Pristimerin protects against inflammation and metabolic disorder in mice through inhibition of NLRP3 inflammasome activation.
Acta pharmacologica Sinica
Excessive activation of NLRP3 inflammasome is associated with the pathogenesis of inflammatory diseases. Pristimerin (Pri) is a quinonoid triterpene derived from traditional Chinese medical herb Celastraceae and Hippocrateaceae. Pri has shown antifungal, antibacterial, antioxidant, and anticancer activities. In this study we investigated whether NLRP3 inflammasome was associated with the anti-inflammatory activity of Pri. We showed that Pri (0.1-0.4 μM) dose-dependently blocked caspase-1 activation and IL-1β maturation in LPS-primed mouse bone-marrow-derived macrophages (BMDMs). Pri specifically inhibited NLRP3 inflammasome activation, had no visible effects on NLRC4 and AIM2 inflammasome activation. Furthermore, we demonstrated that Pri blocked the assembly of the NLRP3 inflammasome via disturbing the interaction between NEK7 and NLRP3; the α, β-unsaturated carbonyl moiety of Pri was essential for NLRP3 inflammasome inactivation. In LPS-induced systemic inflammation mouse model and MSU-induced mouse peritonitis model, preinjection of Pri (500 μg/kg, ip) produced remarkable therapeutic effects via inhibition of NLRP3 inflammasome in vivo. In HFD-induced diabetic mouse model, administration of Pri (100 μg· kg ·d, ip, for 6 weeks) reversed HFD-induced metabolic disorders via suppression of NLRP3 inflammasome activation. Taken together, our results demonstrate that Pri acts as a NLRP3 inhibitor, suggesting that Pri might be useful for the treatment of NLRP3-associated diseases.
Celastrol gel ameliorates imiquimod-induced psoriasis-like dermatitis in mice by targeting Langerhans cells.
Liu Liu,Chen Xi,Lu Yi,Sun Xiao-Ying,Ze Kan,Zhou Ya-Qiong,Li Wei,Li Xin,Li Hong-Jin,Li Bin
Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie
BACKGROUND:Psoriasis is an autoimmune disease mediated by T cells. However, treatment remains a clinical challenge because of its frequent recurrence. Celastrol (Cel), the main active ingredient in Tripterygium wilfordii Hook F, is efficacious in treating autoimmune diseases such as psoriasis. OBJECTIVE:To investigate the effect and mechanism of topical Cel in imiquimod (IMQ)-induced psoriasis-like inflammation in mice. METHODS:Female C57BL/6 and Langerin-diphtheria toxin receptor (DTR) mice were divided into Vehicle group and Cel gel groups. IMQ was used induce psoriasis-like inflammation to establish the mouse model of psoriasis. Hematoxylin and eosin staining was used to observe changes in local inflammatory cells in the skin lesions. Enzyme-linked immunosorbent assay was used to detect protein expression levels. Flow cytometry was used to detect the cell number and cytokine expression. Polymerase chain reaction was used to detect cytokine gene expression. RESULTS:Cel gel targeted the Langerhans cells. In IMQ-induced psoriatic dermatitis, Cel gel reduced the secretion of interleukin (IL)- 23 by Langerhans cells, suppressed the interaction between Langerhans cells and γδT cells, and decreased the number of activated γδT cells and related IL-17 secretion, alleviating psoriasis-like inflammation. Furthermore, Cel gel demonstrated a glucocorticoid-like effect that could impede the recurrence of psoriasis. CONCLUSION:Cel gel reduces the secretion of IL-23 from LCs and inhibits the interaction between LCs and γδT cells to alleviate psoriasis. It also shows an effect similar to that of glucocorticoids, which can prevent psoriasis recurrence. These findings provide a new direction for the clinical treatment of psoriasis and contribute to the development of novel drugs.
Formulation, characterization, and evaluation of in vitro skin permeation and in vivo pharmacodynamics of surface-charged tripterine-loaded nanostructured lipid carriers.
Chen Yan,Zhou Lei,Yuan Ling,Zhang Zhen-hai,Liu Xuan,Wu Qingqing
International journal of nanomedicine
BACKGROUND:Nanostructured lipid carriers (NLCs) are attractive materials for topical drug delivery, and in a previous study, we demonstrated that NLCs loaded with tripterine enhance its deposition. However, the surface charge of nanoparticles influences percutaneous drug penetration. Therefore, we aimed to evaluate the influence of the surface charge of NLCs on in vitro skin permeation and in vivo pharmacodynamics of tripterine and optimize tripterine- loaded NLCs for the treatment of skin diseases. METHODS:Different solid and liquid matrices were selected to prepare cationic, anionic, and neutral NLCs by the solvent evaporation method. The in vitro studies were evaluated by using Franz diffusion cells. The effect of surface-charged NLCs on cellular uptake was appraised across HaCaT and B16BL6 cells. The in vitro and in vivo anticancer activity of surface-charged NLCs was evaluated in B16BL6 cells and melanoma-bearing mice, respectively. RESULTS:The average particle sizes of the cationic, anionic, and neutral NLCs were 90.2 ± 9.7, 87.8 ± 7.4, and 84.5 ± 10.2 nm, respectively; their encapsulation efficiencies were 64.3% ± 5.1%, 67.8% ± 4.4%, and 72.5% ± 4.9%, respectively. In vitro studies showed delayed tripterine release, and the order of skin permeation was cationic NLCs > anionic NLCs > neutral NLCs. Further, in vitro cytotoxicity studies showed that the cationic NLCs had the highest (P < 0.05) inhibition ratio in B16BL6 (melanoma) cells. Moreover, in vivo pharmacodynamic experiments in melanoma-bearing mice indicated that the cationic NLCs had significantly higher (P < 0.05) antimelanoma efficacy than the anionic and neutral NLCs. CONCLUSION:The surface charge of NLCs has a great influence on the skin permeation and pharmacodynamics of tripterine. Cationic tripterine-loaded NLCs could enhance the percutaneous penetration and antimelanoma efficacy of tripterine and offer several advantages over tripterine alone. Therefore, they are promising carriers of tripterine for topical antimelanoma therapy.
The application of natural compounds in uveal melanoma drug discovery.
The Journal of pharmacy and pharmacology
OBJECTIVES:Uveal melanoma (UM) is the most common primary intraocular tumour in adults. UM has a poor overall prognosis and ~50% of patients progress to metastatic disease that has a median survival of 5.2 months. There are currently no proven pharmacological treatments for primary or metastatic UM. Research efforts continue to seek new agents. Many natural compounds have shown promising anti-UM activity in in-vitro and/or in-vivo studies. This review summarises the current findings for natural compounds that may be potentially useful in treating UM. KEY FINDINGS:Literature suggests that natural compounds, such as pristimerin, picropodophyllin, oridonin, zeaxanthin, withaferin and FR-900359, may be promising candidate compounds to treat UM. Most of these compounds have demonstrated satisfactory efficacy in inhibiting in-vitro UM cell growth. SUMMARY:The evidence regarding the anti-UM effects of natural compounds is mainly limited to in-vitro studies; to date, only a small number of these agents have been evaluated in vivo. The molecular mechanisms underpinning the anti-UM properties of these compounds remain largely undefined. Further studies are required to evaluate the in-vivo anticancer activity, appropriate dosage regimen and safety of natural compounds that could be developed for use in UM.
Pristimerin-induced uveal melanoma cell death via inhibiting PI3K/Akt/FoxO3a signalling pathway.
Yan Fengxia,Liao Rifang,Silva Marta,Li Shuai,Jiang Yizhou,Peng Tangming,Lazarovici Philip,Zheng Wenhua
Journal of cellular and molecular medicine
Uveal melanoma (UM) is a highly invasive intraocular malignancy with high mortality. Presently, there is no FDA-approved standard for the treatment of metastatic UM. Pristimerin is a natural quinine methide triterpenoid compound with anti-angiogenic, anti-cancer and anti-inflammatory activities. However, Pristimerin potential cytotoxic effect on UM was poorly investigated. In the present study, we found the migration and invasion of UM-1 cells were inhibited by Pristimerin which also caused a rapid increase of ROS, decreased mitochondrial membrane potential, induced the accumulation of cells in G0/G1 phase, ending with apoptotic cell death. Pristimerin inhibited Akt and FoxO3a phosphorylation and induced nuclear accumulation of FoxO3a in UM-1 cells, increased the expression of pro-apoptotic proteins Bim、p27 , cleaved caspase-3, PARP and Bax, and decreased the expression of Cyclin D1 and Bcl-2. LY294002 or Akt-siRNA inhibited the PI3K/Akt/FoxO3a pathway and promoted the Pristimerin-induced apoptosis, while Pristimerin effects were partially abolished in FoxO3a knockdown UM-1 cell cultures. Taken together, present results showed that Pristimerin induced apoptotic cell death through inhibition of PI3K/Akt/FoxO3a pathway in UM-1 cells. These findings indicate that Pristimerin may be considered as a potential chemotherapeutic agent for patients with UM.
Celastrol inhibits growth and induces apoptotic cell death in melanoma cells via the activation ROS-dependent mitochondrial pathway and the suppression of PI3K/AKT signaling.
Lee Ju-Hye,Won Yeong-Seon,Park Ki-Hun,Lee Mi-Kyung,Tachibana Hirofumi,Yamada Koji,Seo Kwon-Il
Apoptosis : an international journal on programmed cell death
Celastrol has been reported to possess anticancer effects in various cancers; however, the precise mechanism underlying ROS-mediated mitochondria-dependent apoptotic cell death triggered by celastrol treatment in melanoma cells remains unknown. We showed that celastrol effectively induced apoptotic cell death and inhibited tumor growth using tissue culture and in vivo models of B16 melanoma. In addition to apoptotic cell death in B16 cells, several apoptotic events such as PARP cleavage and activation of caspase were confirmed. Pretreatment with caspase inhibitor modestly attenuated the celastrol-induced increase in PARP cleavage and sub-G1 cell population, implying that caspases play a partial role in celastrol-induced apoptosis. Moreover, ROS generation was detected following celastrol treatment. Blocking of ROS accumulation with ROS scavengers resulted in inhibition of celastrol-induced Bcl-2 family-mediated apoptosis, indicating that celastrol-induced apoptosis involves ROS generation as well as an increase in the Bax/Bcl-2 ratio leading to release of cytochrome c and AIF. Importantly, silencing of AIF by transfection of siAIF into cells remarkably attenuated celastrol-induced apoptotic cell death. Moreover, celastrol inhibited the activation of PI3K/AKT/mTOR signaling cascade in B16 cells. Our data reveal that celastrol inhibits growth and induces apoptosis in melanoma cells via the activation of ROS-mediated caspase-dependent and -independent pathways and the suppression of PI3K/AKT signaling.
Topical application of celastrol alleviates atopic dermatitis symptoms mediated through the regulation of thymic stromal lymphopoietin and group 2 innate lymphoid cells.
Lee Jae Kwon,Seok Jin Kyung,Cho Ilyoung,Yang Gabsik,Kim Kyu-Bong,Kwack Seung Jun,Kang Han Chang,Cho Yong-Yeon,Lee Hye Suk,Lee Joo Young
Journal of toxicology and environmental health. Part A
Atopic dermatitis is a chronic inflammatory skin disease, of which incidence is closely related to exposure to environmental pollutants and allergens. Thymic stromal lymphopoietin (TSLP) plays an important role in the early stages of atopic dermatitis development by inducing Th2 immune responses. In addition, TSLP regulates activation of group 2 innate lymphoid cells (ILC2), promoting the pathogenesis of atopic dermatitis. The aim of this study was to investigate whether celastrol alleviated atopic dermatitis symptoms by regulating TSLP expression and ILC2 stimulation. Celastrol suppressed TSLP production in mouse keratinocyte cells by inhibiting NF-ĸB activation. Topical application of celastrol significantly improved atopic dermatitis symptoms induced by house dust mite (HDM) in NC/Nga mice as determined by dermatitis score and histological assessment. Celastrol decreased the levels of TSLP in atopic dermatitis skin lesions of HDM-stimulated NC/Nga mice. Celastrol reduced levels of Th2 cytokines including IL-4, IL-5, and IL-13 in atopic dermatitis skin lesions of NC/Nga mice. Further, celastrol significantly reduced ILC2 population in atopic dermatitis skin lesions of NC/Nga mice. These results indicate that topical application of celastrol improved atopic dermatitis symptoms by lowering TSLP levels and concomitant immune responses. Data demonstrated that reduced TSLP levels and associated lower number of ILC2 cells alleviate atopic dermatitis symptoms induced by house dust mite.
An effective and safe treatment strategy for rheumatoid arthritis based on human serum albumin and Kolliphor HS 15.
Gong Ting,Zhang Pei,Deng Caifeng,Xiao Yu,Gong Tao,Zhang Zhirong
Nanomedicine (London, England)
We aimed to construct human serum albumin-Kolliphor HS 15 nanoparticles (HSA-HS15 NPs) to overcome the limitations in targeted therapy for rheumatoid arthritis (RA) and enhance the safety of drug-loaded HSA NPs. Celastrol (CLT)-loaded HSA-HS15 NPs were prepared and the properties were adequately investigated; the treatment effect were evaluated in RA rats; and studies were performed to explain the mechanism. CLT-HSA-HS15 NPs had remarkable treatment ability and enhanced safety in the treatment of RA compared with free CLT and CLT-HSA NPs. HSA-HS15 NPs could be a safe and efficient therapeutic strategy for the treatment of RA, because of the inflammatory targeting ability of albumin, the added HS15 and ELVIS effect (extravasation through leaky vasculature followed by inflammatory cell-mediated sequestration) of nanoparticles.
Palmitic acid-modified bovine serum albumin nanoparticles target scavenger receptor-A on activated macrophages to treat rheumatoid arthritis.
Gong Ting,Tan Tiantian,Zhang Pei,Li Haohuan,Deng Caifeng,Huang Yuan,Gong Tao,Zhang Zhirong
Palmitic acid-modified bovine serum albumin (PAB) was synthetized and found to own remarkable scavenger receptor-A (SR-A) targeting ability in vitro and in vivo, through which activated macrophages took up PAB nanoparticles (PAB NPs) 9.10 times more than bovine serum albumin nanoparticles (BSA NPs) and PAB NPs could delivery anti-inflammatory drugs celastrol (CLT) to inflamed tissues more effectively than BSA NPs. Compared with chondroitin sulfate modified BSA NPs targeting activated macrophages via CD44, PAB NPs show a more prominent targeting effect whether in vivo or in vitro. And PAB also demonstrated excellent biosafety compared to maleylated BSA, a known SR-A ligand that was lethal in our study. Furthermore, in adjuvant-induced arthritis rats, CLT-PAB NPs significantly improved disease pathology at a lower CLT dose with high safety, compared with CLT-BSA NPs. In addition, compared with the existing ligands with SR-A targeting due to strong electronegativity, the enhanced electronegativity and introduced PA are both important for the SR-A targeting effect of PAB. Therefore, PAB provides a novel direction for the treatment of rheumatoid arthritis and design of new ligands of SR-A.
Subcellular co-delivery of two different site-oriented payloads based on multistage targeted polymeric nanoparticles for enhanced cancer therapy.
You Chao-Qun,Wu Hong-Shuai,Gao Zhi-Guo,Sun Kai,Chen Fang-Hui,Tao W Andy,Sun Bai-Wang
Journal of materials chemistry. B
The co-delivery of two or more anti-tumor agents using nanocarriers has shown great promise in cancer therapy, but more work is needed to selectively target drugs to specific subcellular organelles. To this end, our research has reported on "smart" polymeric nanoparticles that can encapsulate two different site-oriented pro-drug molecules, allowing them to reach their targeted subcellular organelles based on NIR-mediated controlled release, allowing for targeted modifications in the nucleus or the mitochondria. Specially, an all-trans retinoic acid (RA) conjugated cisplatin derivative (RA-Pt) can be delivered with high affinity to the nucleus of target cells, facilitating the binding of cisplatin to double-stranded DNA. Similarly, a synthesized derivative generated by conjugation of triphenylphosphine (TPP) and celastrol (TPP-Cet) may facilitate mitochondrial targeted drug delivery in tumor cells, inducing ROS accumulation and thereby leading to apoptosis. Relative to nanoparticles loaded with a single therapeutic agent, dual antitumor agent-loaded nanocarriers showed promising synergy, exhibiting significant tumor inhibition in vivo (81.5%), and less systemic toxicity than the free therapeutic agents alone or the drug-loaded nanoparticles without targeted ligands. These results indicated that site-oriented payloads can effectively enhance antitumor therapeutic efficiency and these studies offer a novel "multistage targeted-delivery" strategy in synergistic therapy for cancer treatment.
Transferrin-Functionalized Microemulsions Coloaded with Coix Seed Oil and Tripterine Deeply Penetrate To Improve Cervical Cancer Therapy.
Guo Mengfei,Qu Ding,Qin Yue,Chen Yunyan,Liu Yuping,Huang Mengmeng,Chen Yan
Tumor-targeted ligand modification and nanosized coloaded drug delivery systems are promising for cancer therapy. In this study, we showed that coix seed oil and tripterine coloaded microemulsions with a transferrin modification (Tf-CT-MEs) could improve the treatment of cervical cancer. Tf-CT-MEs exhibited good stability in serum and a notably synergistic antiproliferation effect. In the HeLa xenograft tumor-bearing mouse model, Tf-CT-MEs accumulated at tumor sites and penetrated deeply in tumor tissues. Tf-CT-MEs had superior anticancer efficacy in vivo, which greatly slowed the growth of tumors (*** < 0.001 vs saline). We also found that Tf-CT-MEs inhibited tumor cell proliferation, enhanced antiangiogenesis, and induced apoptosis by regulating bax/bcl-2 and the activating caspase-3 pathway. Tf-CT-MEs decreased by 27.7, 26.9, 61.2, and 42.5% of concentrations of TGF-β1, CCL2, TNF-α, and IL-6 in serum, respectively. In addition, Tf-CT-MEs showed little toxicity in vital organs. These results were due to the improved drug delivery efficiency. Collectively, Tf-CT-MEs enhance tumor-targeting, facilitate deep penetration of drugs, and have promising potential as an efficient treatment for cervical cancer.
Celastrol inhibits aminoglycoside-induced ototoxicity via heat shock protein 32.
Francis S P,Kramarenko I I,Brandon C S,Lee F-S,Baker T G,Cunningham L L
Cell death & disease
Hearing loss is often caused by death of the mechanosensory hair cells of the inner ear. Hair cells are susceptible to death caused by aging, noise trauma, and ototoxic drugs, including the aminoglycoside antibiotics and the antineoplastic agent cisplatin. Ototoxic drugs result in permanent hearing loss for over 500,000 Americans annually. We showed previously that induction of heat shock proteins (HSPs) inhibits both aminoglycoside- and cisplatin-induced hair cell death in whole-organ cultures of utricles from adult mice. In order to begin to translate these findings into a clinical therapy aimed at inhibiting ototoxic drug-induced hearing loss, we have now examined a pharmacological HSP inducer, celastrol. Celastrol induced upregulation of HSPs in utricles, and it provided significant protection against aminoglycoside-induced hair cell death in vitro and in vivo. Moreover, celastrol inhibited hearing loss in mice receiving systemic aminoglycoside treatment. Our data indicate that the major heat shock transcription factor HSF-1 is not required for celastrol-mediated protection. HSP32 (also called heme oxygenase-1, HO-1) is the primary mediator of the protective effect of celastrol. HSP32/HO-1 inhibits pro-apoptotic c-Jun N-terminal kinase (JNK) activation and hair cell death. Taken together, our data indicate that celastrol inhibits aminoglycoside ototoxicity via HSP32/HO-1 induction.
Celastrol, an oral heat shock activator, ameliorates multiple animal disease models of cell death.
Sharma Sudhish,Mishra Rachana,Walker Brandon L,Deshmukh Savitha,Zampino Manuela,Patel Jay,Anamalai Mani,Simpson David,Singh Ishwar S,Kaushal Shalesh,Kaushal Sunjay
Cell stress & chaperones
Protein homeostatic regulators have been shown to ameliorate single, loss-of-function protein diseases but not to treat broader animal disease models that may involve cell death. Diseases often trigger protein homeostatic instability that disrupts the delicate balance of normal cellular viability. Furthermore, protein homeostatic regulators have been delivered invasively and not with simple oral administration. Here, we report the potent homeostatic abilities of celastrol to promote cell survival, decrease inflammation, and maintain cellular homeostasis in three different disease models of apoptosis and inflammation involving hepatocytes and cardiomyocytes. We show that celastrol significantly recovers the left ventricular function and myocardial remodeling following models of acute myocardial infarction and doxorubicin-induced cardiomyopathy by diminishing infarct size, apoptosis, and inflammation. Celastrol prevents acute liver dysfunction and promotes hepatocyte survival after toxic doses of thioacetamide. Finally, we show that heat shock response (HSR) is necessary and sufficient for the recovery abilities of celastrol. Our observations may have dramatic clinical implications to ameliorate entire disease processes even after cellular injury initiation by using an orally delivered HSR activator.
A Microfluidic Co-Flow Route for Human Serum Albumin-Drug-Nanoparticle Assembly.
Hakala Tuuli A,Davies Sarah,Toprakcioglu Zenon,Bernardim Barbara,Bernardes Gonçalo J L,Knowles Tuomas P J
Chemistry (Weinheim an der Bergstrasse, Germany)
Nanoparticles are widely studied as carrier vehicles in biological systems because their size readily allows access through cellular membranes. Moreover, they have the potential to carry cargo molecules and as such, these factors make them especially attractive for intravenous drug delivery purposes. Interest in protein-based nanoparticles has recently gained attraction due to particle biocompatibility and lack of toxicity. However, the production of homogeneous protein nanoparticles with high encapsulation efficiencies, without the need for additional cross-linking or further engineering of the molecule, remains challenging. Herein, we present a microfluidic 3D co-flow device to generate human serum albumin/celastrol nanoparticles by co-flowing an aqueous protein solution with celastrol in ethanol. This microscale co-flow method resulted in the formation of nanoparticles with a homogeneous size distribution and an average size, which could be tuned from ≈100 nm to 1 μm by modulating the flow rates used. We show that the high stability of the particles stems from the covalent cross-linking of the naturally present cysteine residues within the particles formed during the assembly step. By choosing optimal flow rates during synthesis an encapsulation efficiency of 75±24 % was achieved. Finally, we show that this approach achieves significantly enhanced solubility of celastrol in the aqueous phase and, crucially, reduced cellular toxicity.
Novel Low-Toxic Derivative of Celastrol Maintains Protective Effect against Acute Renal Injury.
Hu Xun,Jia Mengdi,Fu Yu,Zhang Pei,Zhang Zhirong,Lin Qing
This study aimed to novelly design and synthesize an amide derivative as a potential substitute of celastrol (CLT). We constituted the compound celastrol-glucosamine (CLG) by conjugating 1-(2-aminoethoxy)-2-glucosamine to celastrol (CLT) and confirmed its chemical structure by H NMR, C NMR, and LC-MS/MS. Then, the potential efficacy of the CLG was investigated on renal ischemia-reperfusion injury animal models. The results demonstrated that the decorated compound CLG could completely reverse the disease progression as same as CLT. Furthermore, the toxicity of CLG was also fully evaluated in rat blood, liver, kidney, heart, spleen, lung, and reproductive system. Compared to the performance of CLT on normal organs, CLG could remarkably maintain high safety and significantly reduce the side effects. Taken together, the CLG could keep the same efficacy as CLT while processing lower toxicity in vivo.
Lactoferrin-dual drug nanoconjugate: Synergistic anti-tumor efficacy of docetaxel and the NF-κB inhibitor celastrol.
Abdelmoneem Mona A,Abd Elwakil Mahmoud M,Khattab Sherine N,Helmy Maged W,Bekhit Adnan A,Abdulkader Mohammad A,Zaky Amira,Teleb Mohamed,Elkhodairy Kadria A,Albericio Fernando,Elzoghby Ahmed O
Materials science & engineering. C, Materials for biological applications
Despite the progress in cancer nanotherapeutics, some obstacles still impede the success of nanocarriers and hinder their clinical translation. Low drug loading, premature drug release, off-target toxicity and multi-drug resistance are among the most difficult challenges. Lactoferrin (LF) has demonstrated a great tumor targeting capacity via its high binding affinity to low density lipoprotein (LDL) and transferrin (Tf) receptors overexpressed by various cancer cells. Herein, docetaxel (DTX) and celastrol (CST) could be successfully conjugated to LF backbone for synergistic breast cancer therapy. Most importantly, the conjugate self-assembled forming nanoparticles of 157.8 nm with elevated loading for both drugs (6.94 and 5.98% for DTX and CST, respectively) without risk of nanocarrier instability. Moreover, the nanoconjugate demonstrated enhanced in vivo anti-tumor efficacy in breast cancer-bearing mice, as reflected by a reduction in tumor volume, prolonged survival rate and significant suppression of NF-κB p65, TNF-α, COX-2 and Ki-67 expression levels compared to the group given free combined DTX/CST therapy and to positive control. This study demonstrated the proof-of-principle for dual drug coupling to LF as a versatile nanoplatform that could augment their synergistic anticancer efficacy.
Synthesis and Biological Evaluation of Celastrol Derivatives with Improved Cytotoxic Selectivity and Antitumor Activities.
Hu Xiao-Long,He Qi-Wei,Long Huan,Zhang Li-Xin,Wang Rong,Wang Bao-Lin,Feng Jia-Hao,Wang Quan,Hou Ji-Qin,Zhang Xiao-Qi,Ye Wen-Cai,Wang Hao
Journal of natural products
Cdc37 associates kinase clients to Hsp90 and promotes the development of cancers. Celastrol, a natural friedelane triterpenoid, can disrupt the Hsp90-Cdc37 interaction to provide antitumor effects. In this study, 31 new celastrol derivatives, -, -, and -, were designed and synthesized, and their Hsp90-Cdc37 disruption activities and antiproliferative activities against cancer cells were evaluated. Among these compounds, , with the highest tumor cell selectivity (15.4-fold), potent Hsp90-Cdc37 disruption activity (IC = 1.9 μM), and antiproliferative activity against MDA-MB-231 cells (IC = 0.2 μM), was selected as the lead compound. Further studies demonstrated has strong antitumor activities both in vitro and in vivo through disrupting the Hsp90-Cdc37 interaction and inhibiting angiogenesis. In addition, exhibited less toxicity than celastrol and showed a good pharmacokinetics profile in vivo. These findings suggest that may be a promising candidate for development of new cancer therapies.
Nanoparticles based on polymers modified with pH-sensitive molecular switch and low molecular weight heparin carrying Celastrol and ferrocene for breast cancer treatment.
Qian Yun,Zhang Jun,Xu Rui,Li Qiang,Shen Qi,Zhu Guofu
International journal of biological macromolecules
Triple negative breast cancer (TNBC) metastasis is still one of the obstacles in clinical treatment, while highly-effective cancer drugs usually cannot be used for their hydrophobicity and comprehensive system toxicity. This study built a kind of pH-sensitive nanoparticles (PP/H NPs) constructed by poly (lactic-co-glycolic acid) modified with β-cyclodextrin (PLGA-β-CD), polyethyleneimine grafted with benzimidazole (PEI-BM) and low molecular weight heparin (LMWH) to delivery Celastrol (Cela) and ferrocene (Fc) for breast cancer therapy. PLGA-β-CD and PEI-BM were synthesized by amidation reaction, the amphipathic polymer nanoparticles with 108.37 ± 1.02 nm were self-assembled in water. After PP/H NPs treatment, the half maximal inhibitory concentration (IC) decreased by 91% compared with Cela, and ROS level was also elevated. PP/H NPs led to substantial tumor inhibiting rate (TIR, 65.86%), utilized LMWH to strengthen the anti-metastasis effect of PP/H NPs. PP/H NPs took advantage of exogenous chemotherapeutics and endogenous ROS to inhibit tumor growth, and combined with LMWH to hinder breast cancer metastasis.
Design, Synthesis and In Vitro Investigation of Novel Basic Celastrol Carboxamides as Bio-Inspired Leishmanicidal Agents Endowed with Inhibitory Activity against Hsp90.
Bassanini Ivan,Parapini Silvia,Ferrandi Erica E,Gabriele Elena,Basilico Nicoletta,Taramelli Donatella,Sparatore Anna
The natural triterpene celastrol () is here used as lead compound for the design and synthesis of a panel of eleven carboxamides that were tested in vitro for their growth inhibitory activity against and parasites. Among them, in vitro screening identified four basic carboxamides endowed with nanomolar leishmanicidal activity, against both the promastigotes and the intramacrophage amastigotes forms. These compounds also showed low toxicity toward two human (HMEC-1 and THP-1) and one murine (BMDM) cell lines. Interestingly, the most selective analogue (compound ) was also endowed with the ability to inhibit the ATPase activity of the protein chaperone Hsp90 as demonstrated by the in vitro assay conducted on a purified, full-length recombinant protein. Preliminary investigations by comparing it with the naturally occurring Hsp90 active site inhibitor Geldanamycin () in two different in vitro experiments were performed. These promising results set the basis for a future biochemical investigation of the mode of interaction of celastrol and -inspired compounds with Hsp90.
Current advances in the nano-delivery of celastrol for treating inflammation-associated diseases.
Fang Guihua,Tang Bo
Journal of materials chemistry. B
Inflammation is ubiquitous in the body, and uncontrolled inflammation often contributes to various diseases. Celastrol, a compound isolated from a Chinese medicinal herb, holds great potential in treating multiple inflammation-associated diseases. However, its further clinical use is limited by its poor solubility, bioavailability, and high organ toxicity. With the advancement of nanotechnology, the nano-delivery of celastrol can effectively improve its oral bioavailability, maximize its efficacy and minimize its side effects. Here, we summarize the roles of celastrol in the treatment of various inflammation-associated diseases, with a special emphasis on its role in modulating immune cell signaling or non-immune cell signaling within the inflammatory microenvironment, and we highlight the latest advances in nano-delivery strategies for celastrol to treat diseases associated with inflammation.
Nanotechnology-Based Celastrol Formulations and Their Therapeutic Applications.
Wagh Pushkaraj Rajendra,Desai Preshita,Prabhu Sunil,Wang Jeffrey
Frontiers in pharmacology
Celastrol (also called tripterine) is a quinone methide triterpene isolated from the root extract of (thunder god vine in traditional Chinese medicine). Over the past two decades, celastrol has gained wide attention as a potent anti-inflammatory, anti-autoimmune, anti-cancer, anti-oxidant, and neuroprotective agent. However, its clinical translation is very challenging due to its lower aqueous solubility, poor oral bioavailability, and high organ toxicity. To deal with these issues, various formulation strategies have been investigated to augment the overall celastrol efficacy by attempting to increase the bioavailability and/or reduce the toxicity. Among these, nanotechnology-based celastrol formulations are most widely explored by pharmaceutical scientists worldwide. Based on the survey of literature over the past 15 years, this mini-review is aimed at summarizing a multitude of celastrol nanoformulations that have been developed and tested for various therapeutic applications. In addition, the review highlights the unmet need in the clinical translation of celastrol nanoformulations and the path forward.
Celastrol Enhances the Anti-Liver Cancer Activity of Sorafenib.
Zhang Rui,Chen Zhi,Wu Shu-Sheng,Xu Jun,Kong Ling-Chun,Wei Pei
Medical science monitor : international medical journal of experimental and clinical research
BACKGROUND Sorafenib, a multiple-target-point kinase inhibitor, has been used as a standard treatment for advanced liver cancer and has shown therapeutic benefits. However, resistance often occurs, prompting the need for identification of synergizing agents. Celastrol is a major active ingredient of Tripterygium wilfordii, which can increase the antitumor effect of traditional antitumor drugs. This work focused on the sensitization of liver cancers in use of celastrol combined with sorafenib. MATERIAL AND METHODS The IC50 values of sorafenib and celastrol on cancer cells were determined through MTT assays. The effects of sorafenib on AKT signaling and VEGF levels in sorafenib-treated cancer cells were analyzed by Western blotting and ELISA, respectively. After combined treatment with celastrol and sorafenib, the survival rate of tumor cells was determined by MTT and clonogenic assays, and the apoptosis rate was also determined by flow cytometry. In addition, the in vivo antitumor activity of celastrol combined with sorafenib was evaluated in Hepa1-6 tumor-bearing mice. RESULTS Sorafenib treatment induced the compensatory activation of the AKT pathway and autocrine VEGF in hepatoma cells, which could be reversed by celastrol. Furthermore, celastrol enhanced the growth inhibition and apoptosis induction of cancer cells by sorafenib both in vitro and in vivo and reduced the dosage of sorafenib needed. CONCLUSIONS Celastrol enhances the antitumor activity of sorafenib in HCC tumor cells by suppressing the AKT pathway and VEGF autocrine system.
Celastrol Loaded Nanoparticles With ROS-Response and ROS-Inducer for the Treatment of Ovarian Cancer.
Niu Weina,Wang Jianguo,Wang Qinyao,Shen Jianjun
Frontiers in chemistry
Ovarian cancer is a gynecological cancer from which it is difficult to be completely cured. It is common to use regimens as an effective treatment for ovarian cancer, but these inevitably bring serious side effects. New treatment strategies and special drugs are needed to improve the prognosis of patients. Celastrol is a natural product, isolated from traditional medicine, that has been proven to be curative for inflammation and cancers. However, the non-targeting and low solubility of celastrol limit its clinical application. We prepared celastrol-loaded nanoparticles for the efficient treatment of ovarian cancer via oxidative stress amplification. In this work, a tumor-targeted, ROS-sensitive nanoparticle was designed, synthesized, and assembled into a drug delivery system that used celastrol. Folic acid (FA) groups on the surface of nanoparticles guide them to actively target the surface of the tumor cell membrane. Thioketal (TK) bonds in nanoparticles can be oxidized and broken into -SH within the ROS level of tumor tissues, which causes the breaking of the PEG hydrophilic shell layer of nanoparticles and promotes the release of celastrol. The released celastrol further stimulated the production of ROS and amplified the intracellular ROS level to promote the apoptosis of tumor cells, thus achieving a therapeutic effect on the celastrol treated ovarian cancer.
Celastrol Protects RPE Cells from Oxidative Stress-Induced Cell Death via Activation of Nrf2 Signaling Pathway.
Zhou Yeqi,Zhou Linbin,Zhou Kewen,Zhang Jingyue,Shang Fu,Zhang Xinyu
Current molecular medicine
PURPOSE:Oxidative stress to retinal pigment epithelial (RPE) cells and inflammation are closely related to the pathogenesis of age-related macular degeneration (AMD). Celastrol is a natural compound isolated from the root of Tripterygium wilfordii. Celastrol has been shown to have potent anti-inflammatory and anti-tumor effects in multiple disease models. The objective of this study was to test the anti-oxidative effects of celastrol in RPE cells and to investigate the underlying mechanisms. METHODS:ARPE-19 cells were treated with hydrogen peroxide (H2O2) and menadione alone or in combination with celastrol. Cell viability and apoptosis were examined by CCK-8 and TUNEL assay, respectively. The expression of Nrf2 and its target genes, such as GCLM and HO-1 was determined by Western blotting. The knockdown of Nrf2 was done by transfecting ARPE-19 cells with lentivirus encoding shRNA against Nrf2. The knockdown efficiency was determined by real-time quantitative PCR and Western blotting. RESULTS:Treatment of ARPE-19 cells with celastrol significantly attenuated the toxic effects of both H2O2 and menadione. Treatment with celastrol enhanced the expression of transcription factor Nrf2 and its targets, GCLM and HO-1. Knockdown of Nrf2 expression by shRNA partially abolished the protective effects of celastrol. Chemical inhibition of glutathione synthesis by L-buthionine-S,R-sulfoximine (BSO) completely abolished the protective effects of celastrol against H2O2 and menadione-induced damage. However, chemical inhibition of HO-1 activity by ZnPPIX did not reduce the protective effects of celastrol. CONCLUSION:This study provides evidence that treatment of RPE cells with celastrol shows potent protective effects against oxidative insults via activation of Nrf2 signaling pathway and upregulation of GCLM expression. This finding suggests that celastrol might be used as a potential therapeutic agent for oxidative stress-related eyes diseases, such as AMD.
Metabolomics Reveals that Cysteine Metabolism Plays a Role in Celastrol-Induced Mitochondrial Apoptosis in HL-60 and NB-4 Cells.
Chen Minjian,Yang Jing,Li Lei,Hu Yanhui,Lu Xiaomei,Sun Rongli,Wang Yubang,Wang Xinru,Zhang Xiaoling
Recently, celastrol has shown great potential for inducing apoptosis in acute myeloid leukemia cells, especially acute promyelocytic leukaemia cells. However, the mechanism is poorly understood. Metabolomics provides an overall understanding of metabolic mechanisms to illustrate celastrol's mechanism of action. We treated both nude mice bearing HL-60 cell xenografts in vivo and HL-60 cells as well as NB-4 cells in vitro with celastrol. Ultra-performance liquid chromatography coupled with mass spectrometry was used for metabolomics analysis of HL-60 cells in vivo and for targeted L-cysteine analysis in HL-60 and NB-4 cells in vitro. Flow cytometric analysis was performed to assess mitochondrial membrane potential, reactive oxygen species and apoptosis. Western blotting was conducted to detect the p53, Bax, cleaved caspase 9 and cleaved caspase 3 proteins. Celastrol inhibited tumour growth, induced apoptosis, and upregulated pro-apoptotic proteins in the xenograft tumour mouse model. Metabolomics showed that cysteine metabolism was the key metabolic alteration after celastrol treatment in HL-60 cells in vivo. Celastrol decreased L-cysteine in HL-60 cells. Acetylcysteine supplementation reversed reactive oxygen species accumulation and apoptosis induced by celastrol and reversed the dramatic decrease in the mitochondrial membrane potential and upregulation of pro-apoptotic proteins in HL-60 cells. In NB-4 cells, celastrol decreased L-cysteine, and acetylcysteine reversed celastrol-induced reactive oxygen species accumulation and apoptosis. We are the first to identify the involvement of a cysteine metabolism/reactive oxygen species/p53/Bax/caspase 9/caspase 3 pathway in celastrol-triggered mitochondrial apoptosis in HL-60 and NB-4 cells, providing a novel underlying mechanism through which celastrol could be used to treat acute myeloid leukaemia, especially acute promyelocytic leukaemia.
Celastrol in metabolic diseases: Progress and application prospects.
Xu Shaohua,Feng Yaqian,He Weishen,Xu Wen,Xu Wei,Yang Hongjun,Li Xianyu
Metabolic diseases are becoming increasingly common in modern society. Therefore, it is essential to develop effective drugs or new treatments for metabolic diseases. As an active ingredient derived from plants, celastrol has shown great potential in the treatment of a wide variety of metabolic diseases and received considerable attention in recent years. In reported studies, the anti-obesity effect of celastrol resulted from regulating leptin sensitivity, energy metabolism, inflammation, lipid metabolism and even gut microbiota. Celastrol reversed insulin resistance via multiple routes to protect against type 2 diabetes. Celastrol also showed effects on atherosclerosis, cholestasis and osteoporosis. Celastrol in treating metabolic diseases seem to be versatile and the targets or pathways were diverse. Here, we systematically review the mechanism of action, and the therapeutic properties of celastrol in various metabolic diseases and complications. Based on this review, potential research strategies might contribute to the celastrol's clinical application in the future.
[UPLC-Q-TOF-MS-based metabolomics study of celastrol].
Zhang Ting,Wang Yi-Kun,Zhao Qi,Xiao Xue-Rong,Li Fei
Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica
The mass spectrometry-based metabolomics method was used to systematically investigate the formation of celastrol metabolites,and the effect of celastrol on endogenous metabolites. The mice plasma,urine and feces samples were collected after oral administration of celastrol. Ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry( UPLC-QTOF-MS) was applied to analyze the exogenous metabolites of celastrol and its altered endogenous metabolites. Mass defect filtering was adopted to screen for the exogenous metabolites of celastrol. Multivariate statistical analysis was used to identify the endogenous metabolites affected by celastrol. Celastrol and its eight metabolites were detected in urine and feces of mice,and 5 metabolites of them were reported for the first time. The hydroxylated metabolites were observed in the metabolism of both human liver microsomes and mouse liver microsomes. Further recombinant enzyme experiments revealed CYP3 A4 was the major metabolic enzyme involved in the formation of hydroxylated metabolites. Urinary metabolomics revealed that celastrol can affect the excretion of intestinal bacteria-related endogenous metabolites,including hippuric acid,phenylacetylglycine,5-hydroxyindoleacetic acid,urocanic acid,cinnamoylglycine,phenylproplonylglycine and xanthurenic acid. These results are helpful to elucidate the metabolism and disposition of celastrol in vivo,and its mechanism of action.
Novel complementary antitumour effects of celastrol and metformin by targeting IκBκB, apoptosis and NLRP3 inflammasome activation in diethylnitrosamine-induced murine hepatocarcinogenesis.
Saber Sameh,Ghanim Amal M H,El-Ahwany Eman,El-Kader Eman M Abd
Cancer chemotherapy and pharmacology
One promising strategy for minimizing chemotherapeutic resistance in hepatocellular carcinoma (HCC) is the use of effective chemosensitizers. We studied the complementary multi-targeted molecular mechanisms of metformin and celastrol in mice with diethylnitrosamine-induced HCC to investigate whether metformin could augment the sensitivity of HCC tissue to the effect of celastrol. Simultaneous administration of celastrol (2 mg/kg) and metformin (200 mg/kg) improved liver function, enhanced the histological picture and prolonged survival. Additionally, combination therapy exerted anti-inflammatory activity, as indicated by the decreased levels of TNF-α and IL-6. This protective role could be attributed to inhibition of inflammasome activation. Herein, our data revealed downregulated NLRP3 gene expression, suppressed caspase-1 activity and reduced levels of the active forms of IL-1β and IL-18. Under this condition, pyroptotic activity was suppressed. In contrast, in the celastrol and celastrol + metformin groups, the apoptotic potential was amplified, as revealed by the increase in the caspase-9 and caspase-3 levels and Bax:BCL-2 ratio. In addition to their repressive effect on the gene expression of NFκBp65, TNFR and TLR4, metformin and celastrol inhibited phosphorylation-induced activation of IκBκB and NFκBp65 and decreased IκBα degradation. Combination therapy with metformin and celastrol repressed markers of angiogenesis, metastasis and tumour proliferation, as revealed by the decreased hepatic levels of VEGF, MMP-2/9 and cyclin D1 mRNA, respectively. In conclusion, by inhibiting NLRP3 inflammasome and its prerequisite NFκB signalling, simultaneous administration of metformin and celastrol appears to have additive benefits in the treatment of HCC compared to cela monotherapy. This effect warrants further clinical investigation.
Interrelated Mechanism by Which the Methide Quinone Celastrol, Obtained from the Roots of , Inhibits Main Protease 3CL of COVID-19 and Acts as Superoxide Radical Scavenger.
Caruso Francesco,Singh Manrose,Belli Stuart,Berinato Molly,Rossi Miriam
International journal of molecular sciences
We describe the potential anti coronavirus disease 2019 (COVID-19) action of the methide quinone inhibitor, celastrol. The related methide quinone dexamethasone is, so far, among COVID-19 medications perhaps the most effective drug for patients with severe symptoms. We observe a parallel redox biology behavior between the antioxidant action of celastrol when scavenging the superoxide radical, and the adduct formation of celastrol with the main COVID-19 protease. The related molecular mechanism is envisioned using molecular mechanics and dynamics calculations. It proposes a covalent bond between the S(Cys145) amino acid thiolate and the celastrol A ring, assisted by proton transfers by His164 and His41 amino acids, and a π interaction from Met49 to the celastrol B ring. Specifically, celastrol possesses two moieties that are able to independently scavenge the superoxide radical: the carboxylic framework located at ring E, and the methide-quinone ring A. The latter captures the superoxide electron, releasing molecular oxygen, and is the feature of interest that correlates with the mechanism of COVID-19 inhibition. This unusual scavenging of the superoxide radical is described using density functional theory (DFT) methods, and is supported experimentally by cyclic voltammetry and X-ray diffraction.
Biotransformation of celastrol to a novel, well-soluble, low-toxic and anti-oxidative celastrol-29-O-β-glucoside by Bacillus glycosyltransferases.
Chang Te-Sheng,Wang Tzi-Yuan,Chiang Chien-Min,Lin Yu-Ju,Chen Hui-Lien,Wu Yu-Wei,Ting Huei-Ju,Wu Jiumn-Yih
Journal of bioscience and bioengineering
Celastrol is a quinone-methide triterpenoid isolated from the root extracts of Tripterygium wilfordii (Thunder god vine). Although celastrol possesses multiple bioactivities, the potent toxicity and rare solubility in water hinder its clinical application. Biotransformation of celastrol using either whole cells or purified enzymes to form less toxic and more soluble derivatives has been proven difficult due to its potent antibiotic and enzyme-conjugation property. The present study evaluated biotransformation of celastrol by four glycosyltransferases from Bacillus species and found one glycosyltransferase (BsGT110) from Bacillus subtilis with significant activity toward celastrol. The biotransformation metabolite was purified and identified as celastrol-29-O-β-glucoside by mass and nuclear magnetic resonance spectroscopy. Celastrol-29-O-β-glucoside showed over 53-fold higher water solubility than celastrol, while maintained 50% of the free radical scavenging activity of celastrol. When using zebrafish as the in vivo animal model, celastrol-29-O-β-glucoside exhibited 50-fold less toxicity than celastrol. To our knowledge, the present study is not only the first report describing the biotransformation of celastrol, but also the first one detailing a new compound, celastrol-29-O-β-glucoside, that is generated in the biotransformation process. Moreover, celastrol-29-O-β-glucoside may serve as a potential candidate in the future medicine application due to its higher water solubility and lower toxicity.
Cytochrome P450 catalyses the 29-carboxyl group formation of celastrol.
Zhou Jiawei,Hu Tianyuan,Liu Yuan,Tu Lichan,Song Yadi,Lu Yun,Zhang Yifeng,Tong Yuru,Zhao Yujun,Su Ping,Wu Xiaoyi,Huang Luqi,Gao Wei
Celastrol, a potent anticancer and anti-obesity drug, was first isolated from Tripterygium wilfordii Hook. f. and it is produced in small quantities in many members of the Celastraceae family. The heterologous reconstitution of celastrol biosynthesis could be a promising method for the efficient production of celastrol and natural and unnatural derivatives thereof, yet only part of the biosynthetic pathway is known. Here, we report a cytochrome P450 monooxygenase (TwCYP712K1) from T. wilfordii that performs the three-step oxidation of friedelin to polpunonic acid in the celastrol pathway. Heterologous expression of TwCYP712K1 showed that TwCYP712K1 catalyses not only the transformation of friedelin to polpunonic acid but also the oxidation of β-amyrin or α-amyrin. The role of TwCYP712K1 in the biosynthesis of celastrol was further revealed via RNA interference. Some key residues of TwCYP712K1 were also screened by molecular docking and site-directed mutagenesis. Our results lay a solid foundation for further elucidating the biosynthesis of celastrol and related triterpenoids.
Potential medicinal value of celastrol and its synthesized analogues for central nervous system diseases.
Bai Xue,Fu Rui-Jia,Zhang Shuo,Yue Shi-Jun,Chen Yan-Yan,Xu Ding-Qiao,Tang Yu-Ping
Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie
The central nervous system (CNS) is a vital part of the human nervous system, and the incidence of CNS disease is increasing year by year, which has become a major public health problem and a prominent social problem. At present, the drugs most commonly used in the clinic are receptor regulators, and neurotransmitter inhibitors, but they are accompanied by serious side effects. Therefore, the identification of new drugs and treatment strategies for CNS disease has been a research hotspot in the medical field. Celastrol, a highly bio-active pentacyclic triterpenoid isolated from Tripterygium wilfordii Hook. F, has been proved to have a wide range of pharmacological effects, such as anti-inflammation, immunosuppression, anti-obesity and anti-tumor activity. However, due to its poor water solubility, low bioavailability and toxicity, the clinical development and trials of celastrol have been postponed. However, in recent years, the extensive medical value of celastrol in the treatment of CNS diseases such as nervous system tumors, Alzheimer's disease, Parkinson's disease, cerebral ischemia, multiple sclerosis, spinal cord injury, and amyotrophic lateral sclerosis has gradually attracted intensive attention worldwide. In particular, celastrol has non-negligible anti-tumor efficacy, and as there are no 100% effective anti-tumor drugs, the study of its structural modification to obtain better leading compounds with higher efficiency and lower toxicity has aroused strong interest in pharmaceutical chemists. In this review, research progress on celastrol in CNS diseases and the synthesis of celastrol-type triterpenoid analogues and their application evaluation in disease models, such as CNS diseases and autotoxicity-related target organ cancers in the past decade are summarized in detail, in order to provide reference for future better application in the treatment of CNS diseases.
Design, synthesis of novel celastrol derivatives and study on their antitumor growth through HIF-1α pathway.
Shang Fan-Fan,Wang Jing Ying,Xu Qian,Deng Hao,Guo Hong-Yan,Jin Xuejun,Li Xiaoting,Shen Qing-Kun,Quan Zhe-Shan
European journal of medicinal chemistry
Four series of hypoxia-inducible factor-1 alpha (HIF-1α) functioning derivatives stemming from modifications to the C-29 carboxyl group of celastrol were designed and synthesized, and their anticancer activities were evaluated. To address the structure and activity relationship of each derivative, extensive structural changes were made. HRE luciferase reporter assay demonstrated that 12 modified compounds showed superior HIF-1α inhibitory activity. Among them, compound C6 exhibited the best features: firstly, the strongest HIF-1α inhibitory activity (IC = 0.05 μM, 5-fold higher than that of celastrol); secondly, lower cytotoxicity (22-fold lower, C6-16.85 μM vs celastrol-0.76 μM). Thus, the safety factor of C6 was about 112 times higher than that of celastrol. Western blot assay indicated that C6 may inhibit the expression of HIF-1α protein in cells. Additionally, C6 hindered tumor cell cloning, migration and induced cell apoptosis. It is worth mentioning that in the mouse tumor xenograft model, C6 (10 mg/kg) displayed good antitumor activity in vivo, showing a better inhibition rate (74.03%) than the reference compound 5-fluorouracil (inhibition rate, 59.58%). However, the celastrol treatment group experienced collective death after four doses of the drug. Moreover, C6 minimally affected the mouse weight, indicating that its application in vivo has little toxic effect. H&E staining experiments show that it could also exacerbate the degree of tumor cell damage. The results of water solubility experiment show that the solubility of C6 is increased by 1.36 times than that of celastrol. In conclusion, C6 is a promising antitumor agent through HIF-1α pathway.
Renal targeted delivery of triptolide by conjugation to the fragment peptide of human serum albumin.
Yuan Zhi-xiang,Wu Xiao-juan,Mo Jingxin,Wang Yan-li,Xu Chao-qun,Lim Lee Yong
European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V
We have previously demonstrated that peptide fragments (PFs) of the human serum albumin could be developed as potential renal targeting carriers, in particular, the peptide fragment, PF-A299-585 (A299-585 representing the amino acid sequence of the human serum albumin). In this paper, we conjugated triptolide (TP), the anti-inflammatory Chinese traditional medicine, to PF-A299-585 via a succinic acid spacer to give TPS-PF-A299-585 (TP loading 2.2% w/w). Compared with the free TP, TPS-PF-A299-585 exhibited comparable anti-inflammatory activity in the lipopolysaccharide stimulated MDCK cells, but was significantly less cytotoxic than the free drug. Accumulation of TPS-PF-A299-585 in the MDCK cells in vitro and in rodent kidneys in vivo was demonstrated using FITC-labeled TPS-PF-A299-585. Renal targeting was confirmed in vivo in a membranous nephropathic (MN) rodent model, where optical imaging and analyses of biochemical markers were combined to show that TPS-PF-A299-585 was capable of alleviating the characteristic symptoms of MN. The collective data affirm PF-A299-585 to be a useful carrier for targeting TP to the kidney.
Celastrol: Progresses in structure-modifications, structure-activity relationships, pharmacology and toxicology.
Hou Wei,Liu Bo,Xu Hongtao
European journal of medicinal chemistry
Celastrol, a principal bioactive ingredient of Tripterygium wilfordii Hook F, has gained extensive exploration due to its unique structure features and multiple promising biological activities. This review will focus on the structural modifications, structure-activity relationships, pharmacology, and toxicology of celastrol in the past ten years. We hope this review would be helpful to get a better grasp of the progresses in the field and provide constructive suggestions for the further study of celastrol.
Systemic dendrimer delivery of triptolide to tumor-associated macrophages improves anti-tumor efficacy and reduces systemic toxicity in glioblastoma.
Liaw Kevin,Sharma Rishi,Sharma Anjali,Salazar Sebastian,Appiani La Rosa Santiago,Kannan Rangaramanujam M
Journal of controlled release : official journal of the Controlled Release Society
Novel delivery strategies are necessary to effectively address glioblastoma without systemic toxicities. Triptolide is a therapy derived from the thunder god vine that has shown potent anti-proliferative and immunosuppressive properties but exhibits significant adverse systemic effects. Dendrimer-based nanomedicines have shown great potential for clinical translation of systemic therapies targeting neuroinflammation and brain tumors. Here we present a novel dendrimer-triptolide conjugate that specifically targets tumor-associated macrophages (TAMs) in glioblastoma from systemic administration and exhibits triggered release under intracellular and intratumor conditions. This targeted delivery improves phenotype switching of TAMs from pro- towards anti-tumor expression in vitro. In an orthotopic model of glioblastoma, dendrimer-triptolide achieved significantly improved amelioration of tumor burden compared to free triptolide. Notably, the triggered release mechanism of dendrimer-mediated triptolide delivery significantly reduced triptolide-associated hepatic and cardiac toxicities. These results demonstrate that dendrimers are a promising targeted delivery platform to achieve effective glioblastoma treatment by improving efficacy while reducing systemic toxicities.
Triptolide-loaded nanoparticles targeting breast cancer in vivo with reduced toxicity.
Zheng Wei,Wang Cong,Ding Ruihong,Huang Yahong,Li Yanyi,Lu Yan
International journal of pharmaceutics
Triptolide (TP), a diterpenoid triepoxide that is extracted from the plant Tripterygium wilfordii, has been found to be quite effective for treating many malignant tumors. Although TP was initially considered to be a promising chemotherapeutic agent, its poor solubility and high toxicity limited its potential clinical application. Consequently, we synthesized nanoformulated TP coated with hyaluronic acid (HA) for application in treating breast cancer. Our results showed that TP can prevent tumor progression, but at the cost of significant toxicity. By contrast, using the nanoformulated TP, uptake of drugs into the tumor can be facilitated, which leads to a further increase in efficacy while decreasing systemic toxicity.
Celastrol exerts anti-inflammatory effect in liver fibrosis via activation of AMPK-SIRT3 signalling.
Wang Yuqin,Li Chunling,Gu Jingya,Chen Chang,Duanmu Jiaxin,Miao Jing,Yao Wenjuan,Tao Jinhua,Tu Mengjue,Xiong Biao,Zhao Lingling,Liu Zhaoguo
Journal of cellular and molecular medicine
Celastrol, a pentacyclic tritepene extracted from Tripterygium Wilfordi plant, showing potent liver protection effects on several liver-related diseases. However, the anti-inflammatory potential of celastrol in liver fibrosis and the detailed mechanisms remain uncovered. This study was to investigate the anti-inflammatory effect of celastrol in liver fibrosis and to further reveal mechanisms of celastrol-induced anti-inflammatory effects with a focus on AMPK-SIRT3 signalling. Celastrol showed potent ameliorative effects on liver fibrosis both in activated hepatic stellate cells (HSCs) and in fibrotic liver. Celastrol remarkably suppressed inflammation in vivo and inhibited the secretion of inflammatory factors in vitro. Interestingly, celastrol increased SIRT3 promoter activity and SIRT3 expression both in fibrotic liver and in activated HSCs. Furthermore, SIRT3 silencing evidently ameliorated the anti-inflammatory potential of celastrol. Besides, we found that celastrol could increase the AMPK phosphorylation. Further investigation showed that SIRT3 siRNA decreased SIRT3 expression but had no obvious effect on phosphorylation of AMPK. In addition, inhibition of AMPK by employing compound C (an AMPK inhibitor) or AMPK1α siRNA significantly suppressed SIRT3 expression, suggesting that AMPK was an up-stream protein of SIRT3 in liver fibrosis. We further found that depletion of AMPK significantly attenuated the inhibitory effect of celastrol on inflammation. Collectively, celastrol attenuated liver fibrosis mainly through inhibition of inflammation by activating AMPK-SIRT3 signalling, which makes celastrol be a potential candidate compound in treating or protecting against liver fibrosis.
SAR study of celastrol analogs targeting Nur77-mediated inflammatory pathway.
Chen Ziwen,Zhang Duo,Yan Siwei,Hu Chaochao,Huang Zhenfei,Li Zhuoer,Peng Shuangzhou,Li Xiaotong,Zhu Yi,Yu Hongyu,Lian Baohuan,Kang Qi,Li Mingyu,Zeng Zhiping,Zhang Xiao-Kun,Su Ying
European journal of medicinal chemistry
Nur77, an orphan member of the nuclear receptor superfamily, plays an important role in the regulation of inflammatory processes. Our previous work found that celastrol, a pentacyclic triterpene, bound to Nur77 to inhibit inflammation in a Nur77-dependent manner. Celastrol binding to Nur77 promotes Nur77 translocation from nucleus to cytoplasm, resulting in clearance of inflamed mitochondria and then alleviation of inflammation. Here, we report the design, synthesis, SAR study and biological evaluation of a series of celastrol analogs. A total of 24 celastrol derivatives were made. Compound 3a with a K of 0.87 μM was found to be less toxic than celastrol and could be a hit molecule for further optimization.
Celastrol binds to its target protein via specific noncovalent interactions and reversible covalent bonds.
Zhang Duo,Chen Ziwen,Hu Chaochao,Yan Siwei,Li Zhuoer,Lian Baohuan,Xu Yang,Ding Rong,Zeng Zhiping,Zhang Xiao-Kun,Su Ying
Chemical communications (Cambridge, England)
Celastrol is one of the most studied natural products. Our studies show for the first time that celastrol can bind to its target protein via specific noncovalent interactions that position celastrol next to the thiol group of the reactive cysteine for reversible covalent bond formation. Such specific noncovalent interactions confer celastrol binding specificity and demonstrate the feasibility of improving the efficacy and selectivity of celastrol for therapeutic applications.
Celastrol is a novel selective agonist of cannabinoid receptor 2 with anti-inflammatory and anti-fibrotic activity in a mouse model of systemic sclerosis.
Jiang Xingwu,Chen Si,Zhang Qiansen,Yi Chunyang,He Jiacheng,Ye Xiyun,Liu Mingyao,Lu Weiqiang
Phytomedicine : international journal of phytotherapy and phytopharmacology
BACKGROUND:Increasing evidence indicated that the cannabinoid receptors were involved in the pathogenesis of organ fibrogenesis. PURPOSE:The purpose of this study was to discover novel cannabinoid receptor 2 (CB2) agonist and assess the potential of CB2 activation in treating systemic sclerosis. METHODS:A gaussia princeps luciferase-based split luciferase complementation assay (SLCA) was developed for detection of the interaction between CB2 and β-arrestin2. A library of 366 natural products was then screened as potential CB2 agonist using SLCA approach. Several GPCR functional assays, including HTRF-based cAMP assay and calcium mobilization were also utilized to evaluated CB2 activation. Bleomycin-induced experimental systemic sclerosis was used to assess the in vivo anti-fibrotic effects. Dermal thickness and collagen content were evaluated via H&E and sirius red staining. RESULTS:Celastrol was identified as a new agonist of CB2 by using SLCA. Furthermore, celastrol triggers several CB2-mediated downstream signaling pathways, including calcium mobilization, inhibition of cAMP accumulation, and receptor desensitization in a dose-dependent manner, and it has a moderate selectivity on CB1. In addition, celastrol exhibited the anti-inflammatory properties on lipopolysaccharide (LPS) treated murine Raw 264.7 macrophages and primary macrophages. Finally, we found that celastrol exerts anti-fibrotic effects in the bleomycin-induced systemic sclerosis mouse model accompanied by reduced inflammatory conditions. CONCLUSION:Taken together, celastrol is identified a novel selective CB2 agonist using a new developed arrestin-based SLCA, and CB2 activation by celastrol reduces the inflammatory response, and prevents the development of dermal fibrosis in bleomycin-induced systemic sclerosis mouse model.
[Research progress on triptolide functionalized nanoparticulate drug delivery systems for tumor treatment].
Luo Yao-Yao,Shi Jin-Feng,Chen Liang,Li Jia-Xin,Ma Xiu-Ying,Zhang Jin-Ming,Geng Fu-Neng
Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica
Nowadays,the advantages of traditional Chinese medicine(TCM) for treatment of tumors are increasingly prominent.Triptolide shows wide-spectrum and highly effective anti-tumor activity. Moreover,nano-carrier-based triptolide drug delivery system is more powerful in improving water solubility and pharmacokinetic behavior of the drug,but it is easy to cause toxic and side effects that should not be neglected on human body. Because of tumor vascular heterogeneity and PEGylation dilemma,nanoparticulate drug delivery systems need to overcome multiple physiological and pathological barriers from drug administration to functioning. It is difficult for traditional triptolide nanoparticulate drug delivery systems to achieve active accumulation of nano-drug in tumor tissues and specific drug release in tumor target site solely relying on enhanced permeability and retention effect of solid tumor,limiting their application and clinical transformation in treatment of tumors. Based on the traditional nano-preparation system,the new functionalized nano-drug delivery system further enhances the nano-drug enrichment,penetration and controlled release at the tumor sites,which is of great significance in improving bioavailability,anti-tumor efficacy and reducing the side effects of drugs. In this paper,we summarized and analyzed the researches on new triptolide functionalized nano-drug delivery system from four perspectives,including tumor active targeting,tumor microenvironment response,polymer-drug conjugates,and multidrug co-delivery for tumor treatment,expecting to provide ideas for in-depth research and clinical application of triptolide and some other active anti-tumor TCM ingredients.
Investigation of the influence of glycyrrhizin on the pharmacokinetics of celastrol in rats using LC-MS and its potential mechanism.
Yan Guangkui,Zhang Hanhua,Wang Wei,Li Yuan,Mao Chenghuang,Fang Mingqiao,Yi Xianhong,Zhang Jingdong
Xenobiotica; the fate of foreign compounds in biological systems
1. The aim of this study was to investigate the effects of glycyrrhizin on the pharmacokinetics of celastrol in rats. 2. Twelve male Sprague-Dawley rats were randomly assigned to two groups: control group and test group. Test group was pretreated with glycyrrhizin at a dose of 100 mg/kg/day for 10 days, and then the two groups were orally administered with celastrol at a dose of 1 mg/kg. The concentration of celastrol was determined using a sensitive and reliable LC-MS method. 3. The results showed that glycyrrhizin could significantly decrease the plasma concentration (from 64.36 ng/mL to 38.42 ng/mL) and AUC (from 705.39 to 403.43 μg·h/L) of celastrol in rats. To investigate its potential mechanism, the effects of glycyrrhizin on the transport and metabolic stability of celastrol were investigated using Caco-2 cell monolayer transwell model and rat liver microsome incubation systems. The Caco-2 cell monolayer transwell experiments indicated that glycyrrhizin could increase the efflux ratio of celastrol (4.02 versus 6.51). However, the rat liver microsome incubation experiments showed that glycyrrhizin could significantly increase the intrinsic clearance rate of celastrol from 20.3 ± 3.37 to 38.8 ± 4.18 μL/min/mg protein. 4. In conclusion, these results indicated that the herb-drug interaction between glycyrrhizin and celastrol might occur when they were coadministered.
[Establishment of skin and joint micro-dialysis sampling method of triptolide in vivo by HPLC-MS/MS].
Guan Yong-Mei,Liu Jia,Yu Ya-Ting,Zhu Wei-Feng,Chen Li-Hua,Jin Chen,Zang Zhen-Zhong
Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica
To detect the concentration of triptolide in skin and joint after percutaneous administration,an HPLC-MS/MS method and skin and joint micro-dialysis( MD) method of triptolide were established in this study. The separation was achieved on triple quadrupole( AB QTRAP4500) and phenomenex-C18( 4. 6 mm×150 mm,5 μm,luna) column with acetonitrile-water with 0. 1% formic acid( 65 ∶35) as the mobile phase at a flow rate of 0. 7 m L·min-1. An electrospray ionization( ESI) source was applied and operated in the positive multiple reaction monitoring( MRM) mode. The fragment ion for triptolide was m/z 361. 1→145. 0. The effects of different perfusion [Ringer's,PBS( p H 7. 4),30% ethanol saline]drug concentrations and flow rates on the recovery rate,as well as the relationship between the recovery rate and the loss rate were determined by incremental( dialysis) and reduction( retrodialysis) methods.The reduction method was applied in the in vivo study to investigate and determine the stability of the probe recovery rate in 10 h. The results of HPLC-MS/MS detection method conformed to the requirements of biological samples. The perfusion fluid was 30% ethanol saline. The recovery rate of skin and joint probes in vitro of triptolide increased within the flow rate of 0. 5-2. 5 μL·min-1. In order to increase the timeliness of data and the accuracy,the flow rate was determined to be 1 μL·min-1,and the sample interval was determined to be 0. 5 h. The recovery rate of triptolide in skin and joint probes in vitro and the loss rate were stable and equal despite of change of triptolide concentration within 10-200 μg·L-1. This indicated that the effect of drug concentration on the MD probe recovery rate was small,and the recovery rate could be replaced by the loss rate. The loss rate in vivo using MD method was measured at 10 h,indicating that the transfer rate of triptolide was stable within 10 h. The established method of triptolide in MD and HPLC-MS/MS can be applied to investigate the kinetic in skin and joint after percutaneous administration of triptolide.
Atomic Force Microscopy Study of the Anti-inflammatory Effects of Triptolide on Rheumatoid Arthritis Fibroblast-like Synoviocytes.
Su Zhanhui,Sun Han,Ao Man,Zhao Chunying
Microscopy and microanalysis : the official journal of Microscopy Society of America, Microbeam Analysis Society, Microscopical Society of Canada
High-resolution atomic force microscopy (AFM) was used for the in situ evaluation of the anti-inflammatory effects of triptolide on rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS) to understand the anti-RA effects of triptolide, based on the morphological and biophysical changes observed in RA-FLS. RA-FLS have been reported to play a primary role in inflammatory bone destruction during the development of RA and thus are regarded as an important target for RA treatment. Triptolide pretreatment significantly inhibited tumor necrosis factor-α-induced expression of the interleukin (IL)-1β, IL-6, and IL-8 genes in MH7A cells. Using AFM, we showed that triptolide-induced morphological damage in MH7A cells by inducing significant ultrastructure changes in the membrane, which were closely related to triptolide-induced apoptosis in MH7A cells. Using force measurements determined with AFM, triptolide was shown to increase the stiffness of MH7A cells. These findings not only revealed the strong anti-inflammatory effects of triptolide on RA-FLS, highlighting triptolide as a potential anti-RA agent, but also revealed the possible use of AFM for studying anti-inflammatory responses in RA-FLS, which we expect to be developed into a potential tool for anti-RA drug studies in RA-FLS.
Metabolic alterations in triptolide-induced acute hepatotoxicity.
Zhao Jie,Xie Cen,Mu Xiyan,Krausz Kristopher W,Patel Daxesh P,Shi Xiaowei,Gao Xiaoxia,Wang Qiao,Gonzalez Frank J
Biomedical chromatography : BMC
Triptolide, a major active constitute of Tripterygium wilfordii Hook. F, is prescribed for the treatment of autoimmune diseases in China. One of its most severe adverse effects observed in the clinical use is hepatotoxicity, but the mechanism is still unknown. Therefore, the present study applied an LC/MS-based metabolomic analysis to characterize the metabolomic changes in serum and liver induced by triptolide in mice. Mice were administered triptolide by gavage to establish the acute liver injury model, and serum biochemical and liver histological analyses were applied to assess the degree of toxicity. Multivariate data analyses were performed to investigate the metabolic alterations. Potential metabolites were identified using variable importance in the projection values and Student's t-test. A total of 30 metabolites were observed that were significantly changed by triptolide treatment and the abundance of 29 metabolites was correlated with the severity of toxicity. Pathway analysis indicated that the mechanism of triptolide-induced hepatotoxicity was related to alterations in multiple metabolic pathways, including glutathione metabolism, tricarboxylic acid cycle, purine metabolism, glycerophospholipid metabolism, taurine and hypotaurine metabolism, pantothenate and CoA biosynthesis, pyrimidine metabolism and amino acid metabolism. The current study provides new mechanistic insights into the metabolic alterations that lead to triptolide-induced hepatotoxicity.
Effective inhibition of Th17/Th22 pathway in 2D and 3D human models of psoriasis by Celastrol enriched plant cell culture extract.
Nguyen T,Lestienne F,Cousy A,Mengeaud V,Castex-Rizzi N
Journal of the European Academy of Dermatology and Venereology : JEADV
BACKGROUND:Psoriasis is an immune-mediated inflammatory disease in which the Th17 pathway is mainly involved. Systemic interventions with biologics that specifically block the Th17 pathway are effective to treat severe psoriasis. However, for efficient topical treatment, small molecules are more suitable than antibodies to penetrate and target epidermal keratinocytes, the key players in psoriasis. Celastrol, a well-described triterpene, is present in low amounts in Tripterygium wilfordii roots. By using plant cell culture (PCC), we were able to boost Celastrol production in bioreactors. Here, we evaluated immune modulator effect of Celastrol enriched extract (CEE) in Th17/Th22 psoriasis induced in 2D and 3D human models in vitro in view of its dermatological usage. METHODS:Human CD4 T cells (hCD4), Normal Human Epidermal Keratinocytes (NHEK), micro-epidermis and reconstructed human epidermis (RHE) were preincubated with CEE and reference controls. Then, hCD4 were stimulated by anti-[CD3/CD28] while others were stimulated by Th17/22 cytokines cocktails. Psoriasis biomarkers were assessed by ELISA (hCD4 and RHE), by RT-qPCR (NHEK) or by ICH/ELISA (micro-epidermis). RESULTS:In 2D stimulated models (hCD4 and NHEK), CEE dose dependently inhibited, respectively, the expression of Th17 cytokines and psoriasis induced biomarkers. In 3D models (RHE and micro-epidermis), IL-8 expression was significantly reduced (RHE) and native phenotype was restored by CEE (micro-epidermis). CONCLUSION:These results clearly showed that Th17/Th22 cytokines, main inflammatory parameters, and psoriasis associated key biomarkers were inhibited by CEE in both 2D and 3D human in vitro models. Therefore, skin homeostasis could be restored by these modulator effects. Moreover, this high added value CEE was obtained by an ecofriendly bioprocess in contrast to traditional roots extracts. This is the first time that a well-defined CEE immune modulator has been proposed for psoriasis adjuvant care to reduce inflammation.
Pharmacokinetic and Toxicological Characteristics of Tripterigium Glycosides and Their Derivatives.
Du Xi,Nyagblordzro Makafui,An Lijun,Gao Xue,Du Lemei,Wang Yangyang,Ondieki Gregory,Kikete Siambi,He Xin
Current drug metabolism
BACKGROUND:Tripterigium wilfordii glycosides (TWG) demonstrate paramount bioactive effectiveness in the management of many autoimmune diseases. However, its side effects on the hepatic, nephrotic, reproductive, and cardiovascular systems have limited its immense therapeutic potentials. Triptolide (TP) and Celastrol (CL), the leading bioactive as well as toxic constituents of TWG, have been widely studied. This review aims to summarize the key mechanisms that TWG trigger the toxic reactions and the precautionary measures that could prevent and reduce such reactions. METHOD:We undertook a systemic search of bibliographic databases for peer-reviewed research literature about the toxic mechanisms and pharmacokinetic profiles of TWG. The key points of screened papers were described and combined together to make up whole. RESULTS:Totally 125 papers were referred in this paper, the majority were from Chinese academic associations. It has been reported that reactive oxygen species generation, mitochondrial respiratory chain inhibition, and metabolizing enzyme inhibition are the leading factors of the toxic reactions. The bioactive effects and toxicities of TWG are closely related to its metabolic profiles. It has been confirmed that TP and CL inhibit CYP450 and the transporters. This paper reviews and summarizes the pharmacokinetic parameters of TWG. Antioxidants, polymeric micelle and topical nanoparticle formulations have exhibited potentials in toxicity circumvention. CONCLUSION:A thorough understanding of the pharmacokinetic and toxicological characteristics of TWG combined with further in-depth study will enhance the efficacy and safety in using TWG, which would augment and improve its clinical application in the future.
Advances in phytochemical delivery systems for improved anticancer activity.
Lagoa Ricardo,Silva João,Rodrigues Joaquim Rui,Bishayee Anupam
Natural compounds have significant anticancer pharmacological activities, but often suffer from low bioavailability and selectivity that limit therapeutic use. The present work critically analyzes the latest advances on drug delivery systems designed to enhance pharmacokinetics, targeting, cellular uptake and efficacy of anticancer phytoconstituents. Various phytochemicals, including flavonoids, resveratrol, celastrol, curcumin, berberine and camptothecins, carried by liposomes, nanoparticles, nanoemulsions and films showed promising results. Strategies to avoid drug metabolism, overcome physiological barriers and achieve higher concentration at cancer sites through skin, buccal, nasal, vaginal, pulmonary and colon targeted delivery are presented. Current limitations, challenges and future research directions are also discussed.
Bio-Mimicking Nanoparticles for Targeted Therapy of Malignant Melanoma.
Zhou Xu,Yu Ruilian,Cao Xi,Zhang Zhi-Rong,Deng Li
Journal of biomedical nanotechnology
Polyethylene glycol-poly(lactic-co-glycolic acid) (PEG-PLGA) nanoparticles coated with neutrophil membranes were fabricated to afford a bio-mimicking delivery system and achieve targeted delivery of chemotherapeutics towards malignant melanoma via systemic administration. Using celastrol as the model compound, celastrol-loaded PEG-PLGA nanoparticles coated with neutrophil membranes displayed significantly enhanced cytotoxicity and apoptosis rate in a murine melanoma cell line B16F10 compared to celastrol-loaded PEG-PLGA nanoparticles. Moreover, PEG-PLGA nanoparticles coated with neutrophil membranes exhibited significantly higher internalization efficiency in B16F10 cells than nanoparticles without membrane coating. Next, a B16F10 tumor xenograft mice model was established to explore the biodistribution profiles of PEG-PLGA nanoparticles coated with neutrophil membranes which showed remarkably prolonged blood circulation and more selective accumulation at the tumor site. Celastrol-loaded PEG-PLGA nanoparticles coated with neutrophil membranes also demonstrated greatly improved antitumor efficacy in B16F10 tumor bearing mice xenografts. Taken together, PEG-PLGA nanoparticles coated with neutrophil membranes represent a highly promising nanoscale delivery system to achieve tumor-targeted therapy following systemic administration.
Preclinical studies of celastrol and acetyl isogambogic acid in melanoma.
Abbas Sabiha,Bhoumik Anindita,Dahl Russell,Vasile Stefan,Krajewski Stan,Cosford Nicholas D P,Ronai Ze'ev A
Clinical cancer research : an official journal of the American Association for Cancer Research
PURPOSE:Sensitize melanomas to apoptosis and inhibit their growth and metastatic potential by compounds that mimic the activities of activating transcription factor 2 (ATF2)-driven peptides. EXPERIMENTAL DESIGN:Small-molecule chemical library consisting of 3,280 compounds was screened to identify compounds that elicit properties identified for ATF2 peptide, including (a) sensitization of melanoma cells to apoptosis, (b) inhibition of ATF2 transcriptional activity, (c) activation of c-Jun NH(2)-terminal kinase (JNK) and c-Jun transcriptional activity, and (d) inhibition of melanoma growth and metastasis in mouse models. RESULTS:Two compounds, celastrol (CSL) and acetyl isogambogic acid, could, within a low micromolar range, efficiently elicit cell death in melanoma cells. Both compounds efficiently inhibit ATF2 transcriptional activities, activate JNK, and increase c-Jun transcriptional activities. Similar to the ATF2 peptide, both compounds require JNK activity for their ability to inhibit melanoma cell viability. Derivatives of CSL were identified as potent inducers of cell death in mouse and human melanomas. CSL and a derivative (CA19) could also efficiently inhibit growth of human and mouse melanoma tumors and reduce the number of lung metastases in syngeneic and xenograft mouse models. CONCLUSIONS:These studies show for the first time the effect of CSL and acetyl isogambogic acid on melanoma. These compounds elicit activities that resemble the well-characterized ATF2 peptide and may therefore offer new approaches for the treatment of this tumor type.
Tolerance and efficacy of a new celastrol-containing balm as adjunct care in psoriasis.
Thouvenin M D,Dalmon S,Theunis J,Lauze C,Coubetergues H,Mengeaud V,Calvet B
Journal of the European Academy of Dermatology and Venereology : JEADV
BACKGROUND:In patients with psoriasis, the non-lesional skin also presents abnormalities, requiring emollient application on the whole body. OBJECTIVES:To evaluate the tolerance of a new emollient balm containing celastrol, an active ingredient with anti-Th17 immunomodulatory properties used alone or in association with topical or systemic drug treatments or phototherapy, and its efficacy when used alone. METHODS:Adults with body plaque psoriasis applied the product over the whole body once a day for 4 weeks (balm used alone in 41 patients and with ongoing treatment in 50 patients). At D1, D8 ('balm alone' study) or D15 ('balm in association' study) and D29, the dermatologist rated physical and functional signs and assessed pruritus and body global lesion score (evaluating erythema, induration/thickness, scaling and dryness) in the 'balm alone' study. RESULTS:No reaction related to the product was reported, and the tolerance was deemed excellent. In the 'balm alone' study, mean pruritus intensity score significantly decreased at D8 (-39%, P < 0.001) and D29 (-60%, P < 0.001) compared with D1, together with the body global lesion score (-24% at D8 and -26% at D29, P < 0.001). In parallel, quality of life improved, as evidenced by a patient-reported outcome questionnaire. Cosmetic acceptability was good. CONCLUSION:This new emollient balm was very well tolerated by patients with body plaque psoriasis either alone or in association with drug treatment or phototherapy, which is important to ensure long-term compliance. Daily application during one month improved pruritus, physical signs and quality of life.
Celastrol-induced apoptosis in human HaCaT keratinocytes involves the inhibition of NF-κB activity.
Zhou Lin-Li,Lin Zhi-Xiu,Fung Kwok-Pui,Cheng Christopher H K,Che Chun-Tao,Zhao Ming,Wu Shi-Hua,Zuo Zhong
European journal of pharmacology
Psoriasis is a chronic inflammatory skin disease affecting 1-3% of the world's population. Traditional Chinese medicines have been extensively used for treating psoriasis with promising clinical results. Celastrol, a triterpenoid isolated from a Chinese herb Celastrus orbiculatus caulis, has been known to have diverse pharmacological effects such as anti-inflammatory, anti-cancer and antioxidant activities. The present study aimed at evaluating the anti-proliferative action of celastrol on cultured HaCaT cells and elucidating the mechanisms of action involved. Celastrol was shown to inhibit HaCaT cells growth with an IC₅₀ value of 1.1 μM as measured by MTT assay. The ability of celastrol to induce apoptosis was studied by flow cytometric and western blot analyses. Celastrol was found to be capable of inducing apoptosis in HaCaT cells as characterized by phosphatidyl-serine (PS) externalization, depolarization of mitochondrial membrane potential and activation of caspase-3. The apoptosis induced by celastrol could be suppressed by Z-IETD-FMK and Z-LEHD-FMK, the respective caspase-8 and caspase-9 inhibitor. In addition, western blot analysis revealed a significant augmentation in the protein expression of Bax and attenuation in Bcl-2, suggesting that the celastrol-induced apoptosis acts through both death receptor and mitochondrial pathways. Moreover, western blot analysis on the expression of Rel/NF-κB demonstrated that the celastrol-mediated apoptosis on HaCaT cells was associated with the inhibition of the NF-κB pathway. Taken together, the present project has for the first time identified celastrol as a naturally occurring compound with potent apoptogenic action on cultured human keratinocytes, rendering it a promising candidate for further development into an anti-psoriatic agent.
Loading of water-insoluble celastrol into niosome hydrogels for improved topical permeation and anti-psoriasis activity.
Meng Shikang,Sun Lin,Wang Lun,Lin Zibei,Liu Zeyu,Xi Long,Wang Zhenping,Zheng Ying
Colloids and surfaces. B, Biointerfaces
Psoriasis is a severe disfiguring skin disease affecting approximately 3% of people worldwide and negatively affecting their daily lives. The pathogenesis of psoriasis is complicated, and typical therapeutic strategies for psoriasis mainly focus on anti-inflammation. Considering the side effects, withdrawal rebound, high cost, and many other disadvantages of existing treatments, we developed a new topical therapeutic formulation consisting of niosomes loaded with celastrol, a triterpenoid extracted from Tripterygium. Celastrol niosomes were prepared by the thin film hydration method and probe sonication. The niosomes were composed of Span 20, Span 60, and cholesterol at a weight ratio of 3:1:1. The particle size of the niosomes was approximately 147 nm, with yield of up to 90%. Celastrol niosomes showed improved in vitro permeation ability compared to the raw drug. In our in vivo study, celastrol niosomes effectively alleviated erythema and scaling on the dorsal skin of psoriasis mouse models. Spleen weight and the levels of cytokines, including IL-22, IL-23, and IL-17, decreased after the treatment, indicating the high therapeutic potential of this formulation for psoriasis. In conclusion, encapsulation of celastrol by niosomes increased the water-solubility and permeation of celastrol into the skin, significantly improving its anti-psoriasis activity in mice.
Triptolide-targeted delivery methods.
Xu Hongtao,Liu Bo
European journal of medicinal chemistry
Triptolide, a complex triepoxide diterpene natural product, has attracted considerable interest in the medicinal society due to its multiple biological activities. However, poor water solubility, narrow therapeutic window and multi-organ toxicity have greatly hindered its clinical application. In order to improve its clinical potential, either structural modification or the development of novel targeted delivery systems for triptolide have been executed worldwide in the past decades. In this review, we systematically summarized strategies that have been utilized to develop triptolide-targeted delivery methods, including direct conjugation of triptolide to selected ligands such as sugar, short peptide, oligonucleotide, antibody and most importantly encapsulation of triptolide with well-designed nano-vehicle. Thanks to the potent multiple biological activities of triptolide, either direct conjugation of triptolide to selected ligands or encapsulation of triptolide with nanocarriers could provide better anti-inflammatory or anticancer activity. Thus, these targeted delivery strategies could be taken as a starting point for future utilization of triptolide and also other NPs in experimental clinical therapy.
Therapeutic applications and delivery systems for triptolide.
Viegas Juliana Santos Rosa,Praça Fabíola Garcia,Kravicz Marcelo,Bentley Maria Vitoria Lopes Badra
Drug delivery and translational research
Triptolide (TPL) is a natural compound and active component of Tripterygium wilfordii Hook F., an Asian native woody vine widely used for over 200 years in Chinese medicine. Hot water, ethanol-ethyl acetate, and chloroform-methanol extracts are the first reported TPL preparations in the literature, and since then, several studies for application in inflammation processes and cancer are described due to the antitumor, anti-inflammatory, and immunosuppressive characteristics of the molecule. However, physicochemical properties such as poor solubility and bioavailability are the main concerns regarding the TPL safety and efficacy in clinical studies since trials have reported adverse side effects alongside the excellent TPL therapeutic effects. Here, we review the main TPL applications and issues related to the drug usage, and a comprehensive summary of diseases is provided. Special emphasis is given to drug delivery systems designed to overcome the TPL physicochemical characteristics such as poor drug solubility, and how to increase efficacy and obtain a safe drug profile. Graphical abstract.
Novel nitric oxide-releasing derivatives of triptolide as antitumor and anti-inflammatory agents: Design, synthesis, biological evaluation, and nitric oxide release studies.
Zang Yingda,Lai Fangfang,Fu Junmin,Li Chuangjun,Ma Jie,Chen Chengjuan,Liu Ke,Zhang Tiantai,Chen Xiaoguang,Zhang Dongming
European journal of medicinal chemistry
A series of novel triptolide/furoxans hybrids were designed and synthesized as analogues of triptolide, which is a naturally derived compound isolated from the thunder god vine (Tripterygium wilfordii Hook. F). Some of these synthesized compounds exhibited antiproliferative activities in the nanomolar range. Among them, compound 33 exhibited both good antiproliferative activity and NO-releasing ability and the acute toxicity of compound 33 decreased more than 160 times (LD = 160.9 mg/kg) than triptolide. Moreover, compound 33 significantly inhibited the growth of melanoma at a low dose (0.3 mg/kg) and showed strong anti-inflammatory activity in vitro and in vivo. These results indicate that compound 33 could be a promising candidate for further study.
Celastrol Self-Stabilized Nanoparticles for Effective Treatment of Melanoma.
International journal of nanomedicine
BACKGROUND:Celastrol (CEL), a triterpene extracted from the Chinese herb , has been reported to have profound anticancer activities. However, poor water solubility and high side toxicities have severely restricted the clinical applications of CEL. PURPOSE:We proposed a facile "in situ drug conjugation-induced self-assembly" strategy to prepare CEL-loaded nanoparticles (CEL-NPs) that exhibited enhanced antitumor activity against melanoma. METHODS:First, the CEL was chemically conjugated onto a methoxyl poly(ethylene glycol)--poly(L-lysine) (mPEG-PLL) backbone, resulting in the conversion of the double hydrophilic mPEG-PLL polymer into an amphiphilic polymer prodrug, mPEG-PLL/CEL. The obtained mPEG-PLL/CEL could self-assemble into stable micelles in aqueous solution due to the hydrophobic association of CEL moieties in the side chains and the possible electrostatic interaction between the carboxyl group in CEL and the residue amine group in the PLL segment. Thus, the obtained mPEG-PLL/CEL nanoparticles were named CEL self-stabilized nanoparticles (CEL-NPs), which were then characterized by dynamic light scattering and transmission electron microscopy. Furthermore, the antitumor effects of the CEL-NPs were investigated by an MTT assay in vitro and in a B16F10 tumor-bearing mice model. RESULTS:The CEL-NPs exhibited sustained drug release behavior and were effectively endocytosed by B16F10 cells. Furthermore, the in vivo antitumor evaluation demonstrated that the CEL-NPs had remarkably higher tumor growth inhibition rates and lower systemic side effects than free CEL. CONCLUSION:In summary, our present work not only demonstrates the generation of stable CEL-loaded nanoparticles for the efficient treatment of melanoma but also describes a general way to prepare drug self-stabilized nanomedicine for anticancer therapy.
Suppression of the migration and invasion is mediated by triptolide in B16F10 mouse melanoma cells through the NF-kappaB-dependent pathway.
Jao Hui-Yu,Yu Fu-Shun,Yu Chun-Shu,Chang Shu-Jen,Liu Kuo-Ching,Liao Ching-Lung,Ji Bin-Chuan,Bau Da-Tian,Chung Jing-Gung
Melanoma cancer is one of the major causes of death in humans worldwide. Triptolide is one of the active components of Tripterygium wilfordii Hook F, and has biological activities including induced cell cycle arrest and induction of apoptosis but its antimetastatic effects on murine melanoma cells have not yet been elucidated. Herein, we investigated the effect of triptolide on the inhibition of migration and invasion and possible associated signal pathways in B16F10 murine melanoma cancer cells. Wound healing assay and Matrigel Cell Migration Assay and Invasion System demonstrated that triptolide marked inhibiting the migration and invasion of B16F10 cells. Gelatin zymography assay demonstrated that triptolide significantly inhibited the activities of matrix metalloproteinases-2 (MMP-2). Western blotting showed that triptolide markedly reduced CXCR4, SOS1, GRB2, p-ERK, FAK, p-AKT, Rho A, p-JNK, NF-κB, MMP-9, and MMP-2 but increased PI3K and p-p38 and COX2 after compared to the untreated (control) cells. Real time PCR indicated that triptolide inhibited the gene expression of MMP-2, FAK, ROCK-1, and NF-κB but did not significantly affect TIMP-1 and -2 gene expression in B16F10 cells in vitro. EMSA assay also showed that triptolide inhibited NF-κB DNA binding in a dose-dependent manner. Confocal laser microscopy examination also confirmed that triptolide inhibited the expression of NF-κB in B16F10 cells. Taken together, we suggest that triptolide inhibited B16F10 cell migration and invasion via the inhibition of NF-κB expression then led to suppress MMP-2 and -9 expressions. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1974-1984, 2016.
Inhibition of epithelial ovarian cancer by Minnelide, a water-soluble pro-drug.
Rivard Colleen,Geller Melissa,Schnettler Erica,Saluja Manju,Vogel Rachel Isaksson,Saluja Ashok,Ramakrishnan Sundaram
OBJECTIVE:Minnelide is a water-soluble pro-drug of triptolide, a natural product. The goal of this study was to evaluate the effectiveness of Minnelide on ovarian cancer growth in vitro and in vivo. METHODS:The effect of Minnelide on ovarian cancer cell proliferation was determined by real time electrical impedance measurements. Multiple mouse models with C200 and A2780 epithelial ovarian cancer cell lines were used to assess the efficacy of Minnelide in inhibiting ovarian cancer growth. RESULTS:Minnelide decreased cell viability of both platinum sensitive and resistant epithelial ovarian cancer cells in vitro. Minnelide with carboplatin showed additive effects in vitro. Minnelide monotherapy increased the survival of mice bearing established ovarian tumors. Minnelide, in combination with carboplatin and paclitaxel, improved overall survival of mice. CONCLUSIONS:Minnelide is a promising pro-drug for the treatment of ovarian cancer, especially when combined with standard chemotherapy.
A study of microemulsion systems for transdermal delivery of triptolide.
Chen Huabing,Chang Xueling,Weng Ting,Zhao Xiaozhi,Gao Zhonghong,Yang Yajiang,Xu Huibi,Yang Xiangliang
Journal of controlled release : official journal of the Controlled Release Society
Triptolide possesses immunosuppressive, anti-fertility and anti-cancer activities. Due to its severe toxicity, microemulsions with controlled, sustained and prolonged delivery of triptolide via a transdermal route are expected to reduce its adverse side effects. The purpose of the present study was to investigate the microemulsions for transdermal delivery of triptolide. The pseudo-ternary phase diagrams were developed and various microemulsion formulations were prepared using oleic acid as an oil, Tween 80 as a surfactant and propylene glycol as a cosurfactant. The droplet size of microemulsions was characterized by photocorrelation spectroscopy. The transdermal ability of triptolide from microemulsions was evaluated in vitro using Franz diffusion cells fitted with mouse skins and triptolide was analyzed by high-performance liquid chromatography. The effect of menthol as a permeation enhancer, and the loading dose of triptolide in microemulsions on the permeation rate were also evaluated. The triptolide-loaded microemulsions showed an enhanced in vitro permeation through mouse skins compared to an aqueous solution of 20% propylene glycol containing 0.025% triptolide. The permeation of microemulsions accorded with the Fick's first diffusion law. No obvious skin irritation was observed for the studied microemulsion ME6, but the aqueous solution of 20% propylene glycol containing 0.025% triptolide revealed the significant skin irritation. The results indicate that the studied microemulsion systems, especially ME6, may be promising vehicles for the transdermal delivery of triptolide.
Development of triptolide-nanoemulsion gels for percutaneous administration: physicochemical, transport, pharmacokinetic and pharmacodynamic characteristics.
Yang Meng,Gu Yongwei,Yang Dishun,Tang Xiaomeng,Liu Jiyong
Journal of nanobiotechnology
BACKGROUND:This work aimed to provide useful information on the use of nanoemulsions for the percutaneous administration of triptolide. Lipid nanosystems have great potential for transdermal drug delivery. Nanoemulsions and nanoemulsion gels were prepared to enhance percutaneous permeation. Microstructure and in vitro/in vivo percutaneous delivery characteristics of triptolide (TPL)-nanoemulsions and TPL-nanoemulsion gels were compared. The integrity of the nanoemulsions and nanoemulsion gels during transdermal delivery and its effects on the surface of skin were also investigated. The penetration mechanisms of nanoemulsions and nanoemulsion gels were investigated by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). The transport characteristics of fluorescence-labelled nanoemulsions were probed using laser scanning confocal microscopy. A chronic dermatitis/eczema model in mice ears and the pharmacodynamic of the TPL-nanoemulsion gels were also investigated. RESULTS:Compared to TPL gels, significantly greater cumulative amounts of TPL-nanoemulsion gels and TPL-nanoemulsions penetrated rat skin in vitro. The in vivo microdialysis showed the concentration-time curve AUC for TPL-NPs is bigger than the TPL-gels. At the same time, TPL-NPs had a larger effect on the surface of skin. By hydrating keratin and changing the structure of both the stratum corneum lipids and keratin, nanoemulsions and nanoemulsion gels influence skin to promote percutaneous drug penetration. Both hairfollicles and the stratum corneum are also important in this transdermal drug delivery system. Moderate and high dosages of the TPL-nanoemulsion gels can significantly improve the symptoms of dermatitis/eczema inflammation and edema erythematic in mice ears and can reduce the expression of IFN-γ and IL-4. Moreover, the TPL-nanoemulsion gels cause less gastrointestinal damage than that of the Tripterygium wilfordii oral tablet does. CONCLUSIONS:Nanoemulsions could be suitable for transdermal stably releasing drugs and maintaining the effective drug concentration. The TPL-nanoemulsion gels provided higher percutaneous amounts than other carriers did. These findings suggest that nanoemulsion gels could be promising percutaneous carriers for TPL. The TPL-nanoemulsion gels have a significant treatment effect on dermatitis/eczema in the mice model and is expected to provide a new, low-toxicity and long-term preparation for the clinical treatment of dermatitis/eczema in transdermal drug delivery systems.
Transdermal drug delivery of triptolide-loaded nanostructured lipid carriers: Preparation, pharmacokinetic, and evaluation for rheumatoid arthritis.
Gu Yongwei,Tang Xiaomeng,Yang Meng,Yang Dishun,Liu Jiyong
International journal of pharmaceutics
The objective of this present study was to develop and evaluate the triptolide-loaded nanostructured lipid carriers (TPL-NLCs) for transdermal drug delivery system (TDDS). TPL-NLCs was prepared with emulsification technique and optimized by central composite design of a response surface methodology (CCD-RSM). The optimized TPL-NLCs were spherical and physically stable with the average size of 139.6.0 ± 2.53 nm and Zeta potential of -36.03 ± 2.41 mV. The encapsulation efficiency and drug loading were 97.15% ± 9.46 and 10.35% ± 1.12, respectively. Moreover, the in vitro release study showed that TPL-NLCs had a sustained release profiles and the in vitro penetration study indicated that TPL-NLCs could effectively penetrate into skin. Besides, the methodology of skin-blood synchronous microdialysis was established to evaluate the pharmacokinetics of TPL-NLCs in vivo and the results displayed that the TPL concentration in skin was higher than that in blood. And TPL-NLCs presented a remarkable effect of decreasing knee edema, inhibiting inflammation by regulating the levels of TNF-α, IL-1β and IL-6, which indicated that TPL-NLCs was a promising topical administration in treatment of edema and inflammation associated with rheumatoid arthritis (RA).
[Preparation and transdermal permeation of triptolide and ferulic acid ethosomes gel ].
Tao Ling,He Liang-Fei,Guan Yong-Mei,Chen Li-Hua,Zhu Wei-Feng,Jin Chen,Wu Lu
Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica
The aim of this study was to prepare triptolide and ferulic acid ethosomes gel, investigate its transdermal permeation, and compare the results with ordinary gel and cream. Improved Franz diffusion cell method was used in the transdermal delivery experiment with rat abdominal skin as in vitro model. The receptor fluid at different time points was collected; ferulic acid concentration was determined by high performance liquid chromatography (HPLC) and triptolide concentration was determined by liquid chromatography-electrospray ionization mass spectrometry (LC-MS/MS). Then the penetration rate, transdermal volume and skin reserve of three dosage forms (hydroplasy gel, ordinary gel, and cream) to investigate the transdermal properties of ferulic acid and triptolide in vitro of triptolide and ferulic acid ethosomes gel. The results showed that the steady penetration rate of ferulic acid was 5.268 5, 8.990 9, 12.042 0 μg·cm⁻² ·h⁻¹ respectively in triptolide and ferulic acid ethosomes gel, ordinary gel and cream; the skin retention was (30.234 8±1.525 4), (20.402 6±0.402 6), (7.635 3±1.094 2) μg·cm⁻² . The steady-state permeation rate of triptolide was 67.238 0, 67.238 0 ng·cm⁻² ·h⁻¹ in triptolide and ferulic acid ethosomes gel, about 1.24 times of cream and 3.28 times of ordinary gel; the skin retention was (371.351 4±35.317 1) ng·cm⁻², about 3.35 times of cream and 5.25 times of ordinary gel. Therefore, the ethosomes gel showed good transdermal absorption property and it may be good for clinical safety administration.
Lipid nanoparticles loading triptolide for transdermal delivery: mechanisms of penetration enhancement and transport properties.
Gu Yongwei,Yang Meng,Tang Xiaomeng,Wang Ting,Yang Dishun,Zhai Guangxi,Liu Jiyong
Journal of nanobiotechnology
BACKGROUND:In recent years, nanoparticles (NPs) including nanostructured lipid carries (NLC) and solid lipid nanoparticles (SLN) captured an increasing amount of attention in the field of transdermal drug delivery system. However, the mechanisms of penetration enhancement and transdermal transport properties of NPs are not fully understood. Therefore, this work applied different platforms to evaluate the interactions between skin and NPs loading triptolide (TPL, TPL-NLC and TPL-SLN). Besides, NPs labeled with fluorescence probe were tracked after administration to investigate the dynamic penetration process in skin and skin cells. In addition, ELISA assay was applied to verify the in vitro anti-inflammatory effect of TPL-NPs. RESULTS:Compared with the control group, TPL-NPs could disorder skin structure, increase keratin enthalpy and reduce the SC infrared absorption peak area. Besides, the work found that NPs labeled with fluorescence probe accumulated in hair follicles and distributed throughout the skin after 1 h of administration and were taken into HaCaT cells cytoplasm by transcytosis. Additionally, TPL-NLC could effectively inhibit the expression of IL-4, IL-6, IL-8, IFN-γ, and MCP-1 in HaCaT cells, while TPL-SLN and TPL solution can only inhibit the expression of IL-6. CONCLUSIONS:TPL-NLC and TPL-SLN could penetrate into skin in a time-dependent manner and the penetration is done by changing the structure, thermodynamic properties and components of the SC. Furthermore, the significant anti-inflammatory effect of TPL-NPs indicated that nanoparticles containing NLC and SLN could serve as safe prospective agents for transdermal drug delivery system.
Celastrol analogues as inducers of the heat shock response. Design and synthesis of affinity probes for the identification of protein targets.
Klaić Lada,Morimoto Richard I,Silverman Richard B
ACS chemical biology
The natural product celastrol (1) possesses numerous beneficial therapeutic properties and affects numerous cellular pathways. The mechanism of action and cellular target(s) of celastrol, however, remain unresolved. While a number of studies have proposed that the activity of celastrol is mediated through reaction with cysteine residues, these observations have been based on studies with specific proteins or by in vitro analysis of a small fraction of the proteome. In this study, we have investigated the spatial and structural requirements of celastrol for the design of suitable affinity probes to identify cellular binding partners of celastrol. Although celastrol has several potential sites for modification, some of these were not synthetically amenable or yielded unstable analogues. Conversion of the carboxylic acid functionality to amides and long-chain analogues, however, yielded bioactive compounds that induced the heat shock response (HSR) and antioxidant response and inhibited Hsp90 activity. This led to the synthesis of biotinylated celastrols (23 and 24) that were used as affinity reagents in extracts of human Panc-1 cells to identify Annexin II, eEF1A, and β-tubulin as potential targets of celastrol.
Design, synthesis and antitumor evaluation of novel celastrol derivatives.
Xu Manyi,Li Na,Zhao Zihao,Shi Zhixian,Sun Jianbo,Chen Li
European journal of medicinal chemistry
On the basis of the hybridization strategy of natural products, a total of 32 novel celastrol hybrids were designed, synthesized and evaluated for their antitumor activities. Most of these derivatives exihibited significant antiproliferative activities compared to celastrol, among which compound 29 displayed the strongest inhibitory capability [IC = 0.15 ± 0.03 μM (A549),0.17 ± 0.03 μM (MCF-7), 0.26 ± 0.02 μM (HepG2)], which exhibited equal or superior anti-cancer activities in comparison to 2-cyano-3,12-dioxoolean-1,9 (11)-dien-28-oic acid methyl ester (CDDO-Me). The mechanism of pharmacological research indicated that 29 possessed the ability to disrupt Hsp90-Cdc37 complex which was stronger than celastrol. Meanwhile, compound 29 could induce abnormal regulation of clients (p-Akt and Cdk4) of Hsp90 and cell cycle arrest at G/G phase in a concentration-dependent manner. In addition, compound 29 could also induce cell apoptosis through the death receptor pathway on A549 cells. Taken together, our results demonstrated that 29 might be a promising novel candidate for further druggability research.
HSP90 inhibitor, celastrol, arrests human monocytic leukemia cell U937 at G0/G1 in thiol-containing agents reversible way.
Peng Bin,Xu Limin,Cao Fanfan,Wei Tingxuan,Yang Chunxin,Uzan Georges,Zhang Denghai
BACKGROUND:Because some of heat shock protein 90's (HSP90) clients are key cell cycle regulators, HSP90 inhibition can affect the cell cycle. Recently, celastrol is identified both as a novel inhibitor of HSP90 and as a potential anti-tumor agent. However, this agent's effects on the cell cycle are rarely investigated. In this study, we observed the effects of celastrol on the human monocytic leukemia cell line U937 cell cycle. RESULTS:Celastrol affected the proliferation of U937 in a dose-dependent way, arresting the cell cycle at G0/G1 with 400 nM doses and triggering cell death with doses above 1000 nM. Cell cycle arrest was accompanied by inhibition of HSP90 ATPase activity and elevation in HSP70 levels (a biochemical hallmark of HSP90 inhibition), a reduction in Cyclin D1, Cdk4 and Cdk6 levels, and a disruption of the HSP90/Cdc37/Cdk4 complex. The observed effects of celastrol on the U937 cell cycle were thiol-related, firstly because the effects could be countered by pre-loading thiol-containing agents and secondly because celastrol and thiol-containing agents could react with each other to form new compounds. CONCLUSIONS:Our results disclose a novel action of celastrol-- causing cell cycle arrest at G0/G1 phase based upon thiol-related HSP90 inhibition. Our work suggests celastrol's potential in tumor and monocyte-related disease management.
Tough polyacrylamide-tannic acid-kaolin adhesive hydrogels for quick hemostatic application.
Fan Xianmou,Wang Shaobing,Fang Yan,Li Peiyuan,Zhou Weikang,Wang Zhengchao,Chen Mingfeng,Liu Haiqing
Materials science & engineering. C, Materials for biological applications
Adhesive hydrogels for wet and dynamic tissues are important for biomedical applications in order to withstand cyclic loading such as in the case of hemorrhaging control on the curved skins and heart tissues. However, the fabrication of hydrogels with strong mechanical properties, high adhesion strength, and hemostatic efficiency remains a big challenge. Inspired by the great adhesive behavior of mussels and Arion subfuscus, novel adhesive and hemostatic polyacrylamide-tannic acid-kaolin (PAAm-TA-KA) hydrogels were reported in this work. The hydrogels displayed high strength and toughness due to their physical and chemical crosslinking structures. The abundant catechol groups on tannic acid endow the hydrogels with strong and durable adhesion strength of up to 500 kPa on porcine skin. When applied onto human skin, the hydrogels could be easily peeled off without leaving any remains and causing any damages. The kaolin nanoparticles incorporated in the PAAm-TA-KA hydrogels not only served as a physical crosslinking agent, but an activator of the blood clotting factor FXII for accelerating the formation of thrombus. The strong tissue adhesion and blood coagulant potential of the PAAm-TA-KA hydrogels imparted them high hemostatic efficiency. The free-standing, adhesive, tough, cytocompatible, and hemostatic hydrogels are highly promising for traumatic bleeding control materials.
Pharmacogenomic approach reveals a role for the x(c)- cystine/glutamate antiporter in growth and celastrol resistance of glioma cell lines.
Pham Anh-Nhan,Blower Paul E,Alvarado Omar,Ravula Ranadheer,Gout Peter W,Huang Ying
The Journal of pharmacology and experimental therapeutics
The x(c)(-) cystine/glutamate antiporter has been implicated in GSH-based chemoresistance because it mediates cellular uptake of cystine/cysteine for sustenance of intracellular GSH levels. Celastrol, isolated from a Chinese medicinal herb, is a novel heat shock protein 90 (Hsp90) inhibitor with potent anticancer activity against glioma in vitro and in vivo. In search of correlations between growth-inhibitory potency of celastrol in NCI-60 cell lines and microarray expression profiles of most known transporters, we found that expression of SLC7A11, the gene encoding the light chain subunit of x(c)(-), showed a strong negative correlation with celastrol activity. This novel gene-drug correlation was validated. In celastrol-resistant glioma cells that highly expressed SLC7A11, sensitivity to celastrol was consistently increased via treatment with x(c)(-) inhibitors, including glutamate, (S)-4-carboxyphenylglycine, sulfasalazine, and SLC7A11 small interfering RNA. The GSH synthesis inhibitor, buthionine sulfoximine, also increased celastrol sensitivity, whereas the GSH booster, N-acetylcysteine, suppressed its cytotoxicity. Furthermore, the glioma cell lines were dependent on x(c)(-)-mediated cystine uptake for viability, because cystine omission from the culture medium resulted in cell death and treatment with sulfasalazine depleted GSH levels and inhibited their growth. Combined treatment of glioma cells with sulfasalazine and celastrol led to chemosensitization, as suggested by increased celastrol-induced cell cycle arrest, apoptosis, and down-regulation of the Hsp90 client protein, epidermal growth factor receptor. These results indicate that the x(c)(-) transporter provides a useful target for glioma therapy. x(c)(-) inhibitors such as sulfasalazine, a Food and Drug Administration-approved drug, may be effective both as an anticancer drug and as an agent for sensitizing gliomas to celastrol.
Hyaluronic acid-functionalized bilosomes for targeted delivery of tripterine to inflamed area with enhancive therapy on arthritis.
Yang Hailing,Liu Zhenjie,Song Yonglong,Hu Changjiang
Arthritis treatment has been challenging because of low drug exposure to the articular cavity. This study was intended to develop hyaluronic acid (HA)-functionalized bilosomes for targeted delivery of tripterine (Tri), an antiphlogistic phytomedicine, to the inflamed joint via ligand-receptor interaction. Tri-loaded bilosomes (Tri-BLs) with cationic lipid (DOTAP) were prepared by a thin film hydration method followed by HA coating to form HA@Tri-BLs. HA@Tri-BLs were then characterized by particle size (), entrapment efficiency (), and structural morphology. The drug release, hemocompatibility test and cellular uptake were performed to examine the formulation performances of HA@Tri-BLs. The pharmacokinetics and antiarthritic efficacy were evaluated in arthritic models, respectively. The obtained HA@Tri-BLs possessed a of 118.5 nm around with an of 99.56%. HA@Tri-BLs exhibited excellent cellular uptake and targeted delivery efficiency for Tri, which resulted in elongation of circulatory residence time and enhancement of intra-arthritic bioavailability (799.9% relative to Tri solution). The antiarthritic efficacy of HA@Tri-BLs was also significantly superior to uncoated Tri-BLs that gave rise to obvious inflammation resolution. Our findings suggest that HA-functionalized bilosomes are a promising vehicle for articular delivery of antiphlogistic drugs to potentiate their efficacy.
Celastrol Alleviates Gamma Irradiation-Induced Damage by Modulating Diverse Inflammatory Mediators.
Wang Hong,Ahn Kwang Seok,Alharbi Sulaiman Ali,Shair Omar Hm,Arfuso Frank,Sethi Gautam,Chinnathambi Arunachalam,Tang Feng Ru
International journal of molecular sciences
The present study aimed to explore the possible radioprotective effects of celastrol and relevant molecular mechanisms in an in vitro cell and in vivo mouse models exposed to gamma radiation. Human keratinocytes (HaCaT) and foreskin fibroblast (BJ) cells were exposed to gamma radiation of 20Gy, followed by treatment with celastrol for 24 h. Cell viability, reactive oxygen species (ROS), nitric oxide (NO) and glutathione (GSH) production, lipid peroxidation, DNA damage, inflammatory cytokine levels, and NF-κB pathway activation were examined. The survival rate, levels of interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) in blood, and p65 and phospho-p65 expression were also evaluated in mice after exposure to gamma radiation and celastrol treatment. The gamma irradiation of HaCaT cells induced decreased cell viability, but treatment with celastrol significantly blocked this cytotoxicity. Gamma irradiation also increased free radical production (e.g., ROS and NO), decreased the level of GSH, and enhanced oxidative DNA damage and lipid peroxidation in cells, which were effectively reversed by celastrol treatment. Moreover, inflammatory responses induced by gamma irradiation, as demonstrated by increased levels of IL-6, TNF-α, and IL-1β, were also blocked by celastrol. The increased activity of NF-κB DNA binding following gamma radiation was significantly attenuated after celastrol treatment. In the irradiated mice, treatment with celastrol significantly improved overall survival rate, reduced the excessive inflammatory responses, and decreased NF-κB activity. As a NF-κB pathway blocker and antioxidant, celastrol may represent a promising pharmacological agent with protective effects against gamma irradiation-induced injury.
Quinone methides and their prodrugs: a subtle equilibrium between cancer promotion, prevention, and cure.
Dufrasne F,Gelbcke Michel,Neve Jean,Kiss Robert,Kraus Jean-Louis
Current medicinal chemistry
The importance of reactive drug metabolites in the pathogenesis of drug-induced toxicity has been investigated since the early 1950s, mainly to reveal the link between toxic metabolites and chemical carcinogenesis. This review mainly focuses on biologically active compounds, which generate reactive quinone methide (QM) intermediates either directly or after bioactivation. Several examples of anticancer drugs acting through the generation of QM electrophiles are given. The use of those drugs for chemotherapeutic purposes is also discussed. The key feature of those QM-generating drugs is their reactivity toward specific nucleophilic biological targets. Modulation of their reactivity represents a challenge for medicinal chemists because, depending on the reactivity of these QM intermediates, their interaction with critical proteins can alter the function of these key proteins and induce a wide variety of responses with functional consequences. Among the possible consequences, antiproliferative effects could be exploited for chemotherapeutic purposes. Information on how such QM-generating drugs can affect individual target proteins and their functional consequences are required to help the medicinal chemist in the design of more specific QM-generating molecules for chemotherapeutic use.
Reactive oxygen species-responsive nanoprodrug with quinone methides-mediated GSH depletion for improved chlorambucil breast cancers therapy.
Luo Cheng-Qiong,Zhou Yu-Xin,Zhou Tian-Jiao,Xing Lei,Cui Peng-Fei,Sun Minjie,Jin Liang,Lu Na,Jiang Hu-Lin
Journal of controlled release : official journal of the Controlled Release Society
Prodrug-based stimuli-responsive vectors have emerged as highly promising platform. Inspired by the fact that antioxidant systems including glutathione (GSH) make cancer cells adapt to oxidative stress and play a role in the inactivation of alkylating agents like chlorambucil (CHL) inside tumor cells, while arylboronic acid could transform into GSH depleting agent quinone methide (QM) upon degradation by reactive oxygen species (ROS) over-expressed in tumor cells, a ROS-responsive nanoprodrug (denoted by PPAHC) of CHL was established by integrating CHL into diols-containing hydrophilic polymer with self-immolative linker 4-(hydroxymethyl)phenylboronic acid (HPBA). The prodrug could form core-shell nanoparticle and possess high stability during storage. Drug release profile of PPAHC nanoprodrug demonstrated that nature CHL could be quickly released from PPAHC nanoprodrug in the presence of hydrogen peroxide (HO). Moreover, PPAHC nanoprodrug showed improved therapeutic efficiency compared to CHL via anti-proliferative study and cell apoptosis assay. Further measurement of GSH content and ROS levels in tumor cells suggested that the synergistic impact resulted from QM-mediated GSH reduction and CHL-induced further oxidative stress insults to tumor cells. In vivo tumor suppression effect and biocompatibility indicated the superiorities of PPAHC nanoprodrug. Accordingly, PPAHC provides a new approach as a ROS-responsive CHL delivery system and has a great potential for cancer therapy.
Quinone-induced activation of Keap1/Nrf2 signaling by aspirin prodrugs masquerading as nitric oxide.
Dunlap Tareisha,Piyankarage Sujeewa C,Wijewickrama Gihani T,Abdul-Hay Samer,Vanni Michael,Litosh Vladislav,Luo Jia,Thatcher Gregory R J
Chemical research in toxicology
The promising therapeutic potential of the NO-donating hybrid aspirin prodrugs (NO-ASA) includes induction of chemopreventive mechanisms and has been reported in almost 100 publications. One example, NCX-4040 (pNO-ASA), is bioactivated by esterase to a quinone methide (QM) electrophile. In cell cultures, pNO-ASA and QM-donating X-ASA prodrugs that cannot release NO rapidly depleted intracellular GSH and caused DNA damage; however, induction of Nrf2 signaling elicited cellular defense mechanisms including upregulation of NAD(P)H:quinone oxidoreductase-1 (NQO1) and glutamate-cysteine ligase (GCL). In HepG2 cells, the "NO-specific" 4,5-diaminofluorescein reporter, DAF-DA, responded to NO-ASA and X-ASA, with QM-induced oxidative stress masquerading as NO. LC-MS/MS analysis demonstrated efficient alkylation of Cys residues of proteins including glutathione-S-transferase-P1 (GST-P1) and Kelch-like ECH-associated protein 1 (Keap1). Evidence was obtained for alkylation of Keap1 Cys residues associated with Nrf2 translocation to the nucleus, nuclear translocation of Nrf2, activation of antioxidant response element (ARE), and upregulation of cytoprotective target genes. At least in cell culture, pNO-ASA acts as a QM donor, bioactivated by cellular esterase activity to release salicylates, NO(3)(-), and an electrophilic QM. Finally, two novel aspirin prodrugs were synthesized, both potent activators of ARE, designed to release only the QM and salicylates on bioactivation. Current interest in electrophilic drugs acting via Nrf2 signaling suggests that QM-donating hybrid drugs can be designed as informative chemical probes in drug discovery.
Identification of Boronic Acid Derivatives as an Active Form of N-Alkylaminoferrocene-Based Anticancer Prodrugs and Their Radiolabeling with F.
Daum Steffen,Toms Johannes,Reshetnikov Viktor,Özkan Hülya Gizem,Hampel Frank,Maschauer Simone,Hakimioun Amir,Beierlein Frank,Sellner Leopold,Schmitt Michael,Prante Olaf,Mokhir Andriy
N-Alkylaminoferrocene (NAAF)-based prodrugs are activated in the presence of elevated amounts of reactive oxygen species (ROS), which corresponds to cancer specific conditions, with formation of NAAF and p-quinone methide. Both products act synergistically by increasing oxidative stress in cancer cells that causes their death. Though it has already been demonstrated that the best prodrugs of this type retain their antitumor activity in vivo, the effects were found to be substantially weaker than those observed in cell cultures. Moreover, the mechanistic studies of these compounds in vivo are missing. For clarification of these important questions, labeling of the prodrugs with radioactive moieties would be necessary. In this paper, we first observed that the representative NAAF-based prodrugs are hydrolyzed in dilute aqueous solutions to the corresponding arylboronic acids. We confirmed that these products are responsible for ROS amplification and anticancer properties of the parent prodrugs. Next, we developed the efficient synthetic protocol for radiolabeling the hydrolyzed NAAF-based prodrugs by [F]fluoroglucosylation under the conditions of the copper(I)-catalyzed azide-alkyne 1,3-dipolar cycloaddition and used this protocol to prepare one representative hydrolyzed NAAF-based prodrug radiolabeled with F. Finally, we studied the stability of the F-labeled compound in human serum in vitro and in rat blood in vivo and obtained preliminary data on its biodistribution in vivo in mice carrying pancreatic (AR42J) and prostate (PC3) tumors by applying PET imaging studies. The compound described in this paper will help to understand in vivo effects (e.g., pharmacokinetics, accumulation in organs, the nature of side effects) of these prodrugs that will strongly contribute to their advancement to clinical trials.
Activity of aminoferrocene-based prodrugs against prostate cancer.
Schikora Margot,Reznikov Alexander,Chaykovskaya Liudmila,Sachinska Olga,Polyakova Lubov,Mokhir Andriy
Bioorganic & medicinal chemistry letters
We tested cytotoxicity of aminoferrocene-based prodrugs towards human androgen-responsive and unresponsive prostate cancer cell lines LNCaP and DU-145 correspondingly. Two prodrugs were selected, which are both activated at elevated concentrations of ROS with generation of quinone methide (antioxidant system inhibitor) and iron-containing compounds (N-benzylaminoferrocene (prodrug 1) and Fe salts (2)). We observed that only prodrug 1 is active against the selected prostate cancer cells (IC50=11-27 μM) and its activity correlates with the high cell-membrane permeability and increased production of intracellular ROS.
Prodrugs Bioactivated to Quinones Target NF-κB and Multiple Protein Networks: Identification of the Quinonome.
Pierce Emily N,Piyankarage Sujeewa C,Dunlap Tareisha,Litosh Vladislav,Siklos Marton I,Wang Yue-Ting,Thatcher Gregory R J
Chemical research in toxicology
Electrophilic reactive intermediates resulting from drug metabolism have been associated with toxicity and off-target effects and in some drug discovery programs trigger NO-GO decisions. Many botanicals and dietary supplements are replete with such reactive electrophiles, notably Michael acceptors, which have been demonstrated to elicit chemopreventive mechanisms; and Michael acceptors are gaining regulatory approval as contemporary cancer therapeutics. Identifying protein targets of these electrophiles is central to understanding potential therapeutic benefit and toxicity risk. NO-donating NSAID prodrugs (NO-NSAIDs) have been the focus of extensive clinical and preclinical studies in inflammation and cancer chemoprevention and therapy: a subset exemplified by pNO-ASA, induces chemopreventive mechanisms following bioactivation to an electrophilic quinone methide (QM) Michael acceptor. Having previously shown that these NO-independent, QM-donors activated Nrf2 via covalent modification of Keap-1, we demonstrate that components of canonical NF-κB signaling are also targets, leading to the inhibition of NF-κB signaling. Combining bio-orthogonal probes of QM-donor ASA prodrugs with mass spectrometric proteomics and pathway analysis, we proceeded to characterize the quinonome: the protein cellular targets of QM-modification by pNO-ASA and its ASA pro-drug congeners. Further comparison was made using a biorthogonal probe of the "bare-bones", Michael acceptor, and clinical anti-inflammatory agent, dimethyl fumarate, which we have shown to inhibit NF-κB signaling. Identified quinonome pathways include post-translational protein folding, cell-death regulation, protein transport, and glycolysis; and identified proteins included multiple heat shock elements, the latter functionally confirmed by demonstrating activation of heat shock response.
Enhancement of radiation sensitivity in lung cancer cells by celastrol is mediated by inhibition of Hsp90.
Lee Ji-Hyun,Choi Kyu Jin,Seo Woo Duck,Jang Soon Young,Kim Mira,Lee Byong Won,Kim Jun Young,Kang Seongman,Park Ki Hun,Lee Yun-Sil,Bae Sangwoo
International journal of molecular medicine
The radiosensitizing activity of celastrol, a quinone methide triterpene was examined. We found that celastrol treatment of the NCI-H460 lung cancer cell line increased radiation-induced cell killing. The increased radiosensitivity was correlated with decreased levels of Hsp90 clients, such as EGFR, ErbB2 and survivin as well as with increased p53 expression. Celastrol inhibited the ATP-binding activity of Hsp90. Furthermore, celastrol treatment dissociated an Hsp90 client protein, EGFR, and this in turn resulted in degradation of the client protein. These results were not observed with another structurally similar triterpenoid, 6β-acetonyl-22β-hydroxytingenol (TG), suggesting that a specific structural feature of the triterpenoid is required for radiosensitization. Moreover celastrol treatment increased p53 levels by phosphorylating Ser15 and Ser20 residues as well as by inhibiting its proteasomal degradation. Celastrol may be considered an effective radiosensitizer acting as an inhibitor of Hsp90 and a p53 activator. The two activities could be applicable to a broad range of cancer cells with either wild-type or mutant p53 because either activity could be effective for the enhancement of radiation cell killing. Further analysis with other triterpenoids should identify the functional moiety of the structure and additional candidates for effective radiosensitizers, which can be used in combined radiotherapy.
Evaluation of connectivity map-discovered celastrol as a radiosensitizing agent in a murine lung carcinoma model: Feasibility study of diffusion-weighted magnetic resonance imaging.
Jun Hong Young,Kim Tae-Hoon,Choi Jin Woo,Lee Young Hwan,Lee Kang Kyoo,Yoon Kwon-Ha
This study was designed to identify potential radiosensitizing (RS) agents for combined radio- and chemotherapy in a murine model of human lung carcinoma, and to evaluate the in vivo effect of the RS agents using diffusion-weighted magnetic resonance imaging (DW-MRI). Radioresistance-associated genes in A549 and H460 cells were isolated on the basis of their gene expression profiles. Celastrol was selected as a candidate RS by using connectivity mapping, and its efficacy in lung cancer radiotherapy was tested. Mice inoculated with A549 carcinoma cells were treated with single ionizing radiation (SIR), single celastrol (SC), or celastrol-combined ionizing radiation (CCIR). Changes in radiosensitization over time were assessed using DW-MRI before and at 3, 6, and 12 days after therapy initiation. The tumors were stained with hematoxylin and eosin at 6 and 12 days after therapy. The percentage change in the apparent diffusion coefficient (ADC) value in the CCIR group was significantly higher than that in the SC and SIR group on the 12th day (Mann-Whitney U-test, p = 0.05; Kruskal-Wallis test, p < 0.05). A significant correlation (Spearman's rho correlation coefficient of 0.713, p = 0.001) was observed between the mean percentage tumor necrotic area and the mean ADC values after therapy initiation. These results suggest that the novel radiosensitizing agent celastrol has therapeutic effects when combined with ionizing radiation (IR), thereby maximizing the therapeutic effect of radiation in non-small cell lung carcinoma. In addition, DW-MRI is a useful noninvasive tool to monitor the effects of RS agents by assessing cellularity changes and sequential therapeutic responses.
Chemoenzymatic -Quinone Methide Formation.
Doyon Tyler J,Perkins Jonathan C,Baker Dockrey Summer A,Romero Evan O,Skinner Kevin C,Zimmerman Paul M,Narayan Alison R H
Journal of the American Chemical Society
Generation of reactive intermediates and interception of these fleeting species under physiological conditions is a common strategy employed by Nature to build molecular complexity. However, selective formation of these species under mild conditions using classical synthetic techniques is an outstanding challenge. Here, we demonstrate the utility of biocatalysis in generating -quinone methide intermediates with precise chemoselectivity under mild, aqueous conditions. Specifically, α-ketoglutarate-dependent non-heme iron enzymes, CitB and ClaD, are employed to selectively modify benzylic C-H bonds of -cresol substrates. In this transformation, biocatalytic hydroxylation of a benzylic C-H bond affords a benzylic alcohol product which, under the aqueous reaction conditions, is in equilibrium with the corresponding -quinone methide. -Quinone methide interception by a nucleophile or a dienophile allows for one-pot conversion of benzylic C-H bonds into C-C, C-N, C-O, and C-S bonds in chemoenzymatic cascades on preparative scale. The chemoselectivity and mild nature of this platform is showcased here by the selective modification of peptides and chemoenzymatic synthesis of the chroman natural product (-)-xyloketal D.
Biosynthesis, total synthesis, structural modifications, bioactivity, and mechanism of action of the quinone-methide triterpenoid celastrol.
Lu Yun,Liu Yuan,Zhou Jiawei,Li Dan,Gao Wei
Medicinal research reviews
Celastrol, a quinone-methide triterpenoid, was extracted from Tripterygium wilfordii Hook. F. in 1936 for the first time. Almost 70 years later, it is considered one of the molecules most likely to be developed into modern drugs, as it exhibits notable bioactivity, including anticancer and anti-inflammatory activity, and exerts antiobesity effects. In addition, the molecular mechanisms underlying its bioactivity are being widely studied, which offers new avenues for its development as a pharmaceutical reagent. Owing to its potential therapeutic effects and unique chemical structure, celastrol has attracted considerable interest in the fields of organic, biosynthesis, and medicinal chemistry. As several steps in the biosynthesis of celastrol have been revealed, the mechanisms of key enzymes catalyzing the formation and postmodifications of the celastrol scaffold have been gradually elucidated, which lays a good foundation for the future heterogeneous biosynthesis of celastrol. Chemical synthesis is also an effective approach to obtain celastrol. The total synthesis of celastrol was realized for the first time in 2015, which established a new strategy to obtain celastroid natural products. However, owing to the toxic effects and suboptimal pharmacological properties of celastrol, its clinical applications remain limited. To search for drug-like derivatives, several structurally modified compounds were synthesized and tested. This review focuses primarily on the latest research progress in the biosynthesis, total synthesis, structural modifications, bioactivity, and mechanism of action of celastrol. We anticipate that this paper will facilitate a more comprehensive understanding of this promising compound and provide constructive references for future research in this field.