ABSTRACT:Objective: Neutrophil extracellular traps (NETs) defend against acute infections. However, their overexpression causes organ failure during sepsis. Control of NET formation may improve the outcomes of patients with sepsis. Equol, a soybean isoflavone, is a female hormone analog, which prevents inflammation. We evaluated the effects of equol on NET formation in human neutrophils during inflammatory stimulation in vitro . Methods: Healthy volunteers provided blood samples. An enzyme-linked immunosorbent assay assessed serum equol concentrations. Neutrophil extracellular trap formation in neutrophils was induced by lipopolysaccharide treatment. Enzyme-linked immunosorbent assay quantified DNA-binding elastase, and immunostaining assessed NET formation. Reverse-transcription quantitative polymerase chain reaction and Western blotting detected G-protein-coupled receptor 30 (GPR30) or peptidyl arginine deiminase 4 (PAD4) expression. Flow cytometry assessed neutrophil phagocytic ability with inactivated Escherichia coli . Results: In neutrophils derived from males with low-serum equol levels (low-serum equol group), equol significantly decreased DNA-binding elastase levels and NET formation. Equol did not decrease NETs in neutrophils from males with high-serum equol levels. GPR30 expression of neutrophils was higher in the low-serum than in the high-serum equol group. PAD4 mRNA levels and nuclear PAD4 protein expression also decreased more than the vehicle control in the low-serum equol group. Equol did not alter the phagocytic ability of neutrophils. In neutrophils from young females, equol had no inhibitory effect on NET formation. Conclusions: Equol decreases lipopolysaccharide-induced NET formation in neutrophils from males via inhibition of PAD4 expression. Our findings provide a rationale for investigating a new therapeutic approach using equol to control neutrophil activity during sepsis.

A possible link between diet and cancer has long been considered, with growing interest in phytochemicals. Soy isoflavones have been associated with a reduced risk of prostate cancer in Asian populations. Of the soy isoflavones, genistein and daidzein, in particular, have been studied, but recently, equol as a derivative has gained interest because it is more biologically potent. Different mechanisms of action have already been studied for the different isoflavones in multiple conditions, such as breast, gastrointestinal, and urogenital cancers. Many of these mechanisms of action could also be demonstrated in the prostate, both in vitro and in vivo. This review focuses on the known mechanisms of action at the cellular level and compares them between genistein, daidzein, and equol. These include androgen- and estrogen-mediated pathways, regulation of the cell cycle and cell proliferation, apoptosis, angiogenesis, and metastasis. In addition, antioxidant and anti-inflammatory effects and epigenetics are addressed.

BACKGROUND:Inflammatory bowel disease (IBD) is characterized by immune-mediated, chronic inflammation of the intestinal tract. The occurrence of IBD is driven by the complex interactions of multiple factors. The objective of this study was to evaluate the therapeutic effects of IAA in colitis. METHOD:C57/BL6 mice were administered 2.5% DSS in drinking water to induce colitis. IAA, and R-equol were administered by oral gavage and fed a regular diet. The Disease Activity Index was used to evaluate disease activity. The degree of colitis was evaluated using histological morphology, RNA, and inflammation marker proteins. CD45+ CD4+ FOXP3+ Treg and CD45+ CD4+ IL17A+ Th17 cells were detected by flow cytometry. Analysis of the gut microbiome in fecal content was performed using 16S rRNA gene sequencing. Gut microbiome metabolites were analyzed using Untargeted Metabolomics. RESULT:In our study, we found IAA alleviates DSS-induced colitis in mice by altering the gut microbiome. The abundance of significantly increased in the IAA treatment group. ATCC25526 alleviates DSS-induced colitis by increasing the ratio of Foxp3+T cells in colon tissue. R-equol alleviates DSS-induced colitis by increasing Foxp3+T cells, which may be the mechanism by which ATCC25526 alleviates DSS-induced colitis in mice. CONCLUSION:Our study demonstrates that IAA, an indole derivative, alleviates DSS-induced colitis by promoting the production of Equol from which provides new insights into gut homeostasis regulated by indole metabolites other than the classic AHR pathway.

The implications of soy consumption on human health have been a subject of debate, largely due to the mixed evidence regarding its benefits and potential risks. The variability in responses to soy has been partly attributed to differences in the metabolism of soy isoflavones, compounds with structural similarities to estrogen. Approximately one-third of humans possess gut bacteria capable of converting soy isoflavone daidzein into equol, a metabolite produced exclusively by gut microbiota with significant estrogenic potency. In contrast, lab-raised rodents are efficient equol producers, except for those raised germ-free. This discrepancy raises concerns about the applicability of traditional rodent models to humans. Herein, we designed a gnotobiotic mouse model to differentiate between equol producers and non-producers by introducing synthetic bacterial communities with and without the equol-producing capacity into female and male germ-free mice. These gnotobiotic mice display equol-producing phenotypes consistent with the capacity of the gut microbiota received. Our findings confirm the model's efficacy in mimicking human equol production capacity, offering a promising tool for future studies to explore the relationship between endogenous equol production and health outcomes like cardiometabolic health and fertility. This approach aims to refine dietary guidelines by considering individual microbiome differences.

An increasing number of studies have shown that the consumption of soybeans and soybeans products is beneficial to human health, and the biological activity of soy products may be attributed to the presence of Soy Isoflavones (SI) in soybeans. In the intestinal tracts of humans and animals, certain specific bacteria can metabolize soy isoflavones into equol. Equol has a similar chemical structure to endogenous estradiol in the human body, which can bind with estrogen receptors and exert weak estrogen effects. Therefore, equol plays an important role in the occurrence and development of a variety of hormone-dependent malignancies such as breast cancer and prostate cancer. Despite the numerous health benefits of equol for humans, only 30-50% of the population can metabolize soy isoflavones into equol, with individual variation in gut microbiota being the main reason. This article provides an overview of the relevant gut microbiota involved in the synthesis of equol and its anti-tumor effects in various types of cancer. It also summarizes the molecular mechanisms underlying its anti-tumor properties, aiming to provide a more reliable theoretical basis for the rational utilization of equol in the field of cancer treatment.

Osteoarthritis (OA) is a chronic degenerative disease leading to articular cartilage destruction. Menopausal and postmenopausal women are susceptible to both OA and osteoporosis. S-equol, a soy isoflavone-derived molecule, is known to reduce osteoporosis in estrogen-deficient mice, but its role in OA remains unknown. This study aimed to explore the effect of S-equol on different degrees of menopausal OA in female Sprague-Dawley (SD) rats induced by estrogen deficiency caused by bilateral ovariectomy (OVX) combined with intra-articular injection of mono-iodoacetate (MIA). Knee joint histopathological change; serum biomarkers of bone turnover, including N-terminal propeptide of type I procollagen (PINP), C-terminal telopeptide of type I collagen (CTX-I) and N-terminal telopeptide of type I collagen (NTX-I); the cartilage degradation biomarkers hyaluronic acid (HA) and N-terminal propeptide of type II procollagen (PIINP); and the matrix-degrading enzymes matrix metalloproteinases (MMP)-1, MMP-3 and MMP-13, as well as the oxidative stress-inducing molecules nitric oxide (NO) and hydrogen peroxide (HO), were assessed for evaluation of OA progression after S-equol supplementation for 8 weeks. The results showed that OVX without or with MIA injection induced various severity levels of menopausal OA by increasing pathological damage, oxidative stress, and cartilage matrix degradation to various degrees. Moreover, S-equol supplementation could significantly reduce these increased biomarkers in different severity levels of OA. This indicates that S-equol can lessen menopausal OA progression by reducing oxidative stress and the matrix-degrading enzymes involved in cartilage degradation.

Phytoestrogens are plant-derived compounds that have chemical structures and functions similar to estrogen. Phytoestrogens act as ligand-inducible transcription factors involved in cellular growth by binding to estrogen receptors (ERs), specifically ER alpha (ERα) and beta (ERβ). Through this mechanism, phytoestrogens have a physiological function similar to that of the female hormone 17β-estradiol (E2), which can be useful in treating osteoporosis, cardiovascular disease, and cancer. Furthermore, phytoestrogens have been found to elicit various cellular responses depending on their affinity for ERs; in particular, they show a greater affinity with for ERβ. This study aimed to comprehensively analyze the mode of action of eight phytoestrogens, namely kaempferol, coumestrol, glycitein, apigenin, daidzein, genistein, equol, and resveratrol, by evaluating their estrogenic activity as ER ligands. Based on the bioluminescence resonance energy transfer (BRET)-based ER dimerization and transactivation assay results, all the phytoestrogens tested were identified as estrogen agonists by mediating ERα and ERβ dimerization. The specific binding and functions of ERα and ERβ were distinguished by differentiating between their dimerization activity. In addition, this study contributes to advancing our understanding of the overall mechanism of action involving both ERs.

Choriocarcinoma is a malignant cancer that belongs to gestational trophoblastic neoplasia (GTN). Herein, serum metabolomic analysis was performed on 29 GTN patients and 30 healthy individuals to characterize the metabolic variations during GTN progression. Ultimately 24 differential metabolites (DMs) were identified, of which, Equol was down-regulated in GTN patients, whose VIP score is the 3rd highest among the 24 DMs. As an intestinal metabolite of daidzein, the anticancer potential of Equol has been demonstrated in multiple cancers, but not choriocarcinoma. Hence, human choriocarcinoma cell lines JEG-3 and Bewo were used and JEG-3-derived subcutaneous xenograft models were developed to assess the effect of Equol on choriocarcinoma. The results suggested that Equol treatment effectively suppressed choriocarcinoma cell proliferation, induced cell apoptosis, and reduced tumorigenesis. Label-free quantitative proteomics showed that 136 proteins were significantly affected by Equol and 20 proteins were enriched in Gene Ontology terms linked to protein degradation. Tripartite motif containing 21 (TRIM21), a E3 ubiquitin ligase, was up-regulated by Equol. Equol-induced effects on choriocarcinoma cells could be reversed by TRIM21 inhibition. Annexin A2 (ANXA2) interacted with TRIM21 and its ubiquitination was modulated by TRIM21. We found that TRIM21 was responsible for proteasome-mediated degradation of ANXA2 induced by Equol, and the inhibitory effects of Equol on the malignant behaviors of choriocarcinoma cells were realized by TRIM21-mediated down-regulation of ANXA2. Moreover, β-catenin activation was inhibited by Equol, which also depended on TRIM21-mediated down-regulation of ANXA2. Taken together, Equol may be a novel candidate for the treatment for choriocarcinoma.

OBJECTIVES:This study evaluates the impact of equol, a metabolite of soy isoflavone, on bladder dysfunction in rats with bladder outlet obstruction (BOO). In addition, we investigate its potential as a neuroprotective agent for the obstructed bladder and discuss its applicability in managing overactive bladder (OAB). METHODS:Eighteen male Sprague-Dawley rats were divided into three groups (six rats per group) during the rearing period. The Sham and C-BOO groups received an equol-free diet, while the E-BOO group received equol supplementation (0.25 g/kg). At 8 weeks old, rats underwent BOO surgery, followed by continuous cystometry after 4 weeks of rearing. The urinary oxidative stress markers (8-hydroxy-2'-deoxyguanosine and malondialdehyde) were measured, and the bladder histology was analyzed using hematoxylin-eosin, Masson's trichrome, and immunohistochemical staining (neurofilament heavy chain for myelinated nerves, peripherin for unmyelinated nerves, and malondialdehyde). RESULTS:Equol reduced BOO-induced smooth muscle layer fibrosis, significantly prolonged the micturition interval (C-BOO: 193 s, E-BOO: 438 s) and increased the micturition volume (C-BOO: 0.54 mL, E-BOO: 1.02 mL) compared to the C-BOO group. Equol inhibited the increase in urinary and bladder tissue malondialdehyde levels. While the C-BOO group exhibited reduced peripherin alone positive nerve fibers within the smooth muscle layer, equol effectively attenuated this decline. CONCLUSIONS:Equol reduces lipid peroxidation and smooth muscle layer fibrosis in the bladder and exhibited neuroprotective effects on bladder nerves (peripheral nerves) and prevented the development of bladder dysfunction associated with BOO in rats. Consumption of equol is promising for the prevention of OAB associated with BOO.

BACKGROUND:The inflammasome is a cytosolic multiprotein complex associated with multiple autoimmune diseases. Phytochemical compounds in soy () foods, such as isoflavones, have been reported for their anti-inflammatory properties. AIM:the anti-inflammatory activity of DZ (daidzein) and EQ (equol) were investigated in an ex vivo model of LPS-stimulated murine peritoneal macrophages and by molecular docking correlation. METHODS:Cells were pre-treated with DZ (25, 50, and 100 µM) or EQ (5, 10, and 25 µM), followed by LPS stimulation. The levels of PGE, NO, TNF-α, IL-6, and IL-1β were analyzed by ELISA, whereas the expressions of COX-2, iNOS, NLRP3, ASC, caspase 1, and IL-18 were measured by Western blotting. Also, the potential for transcriptional modulation by targeting NF-κB, COX-2, iNOS, NLRP3, ASC, and caspase 1 was investigated by molecular docking. RESULTS:The anti-inflammatory responses observed may be due to the modulation of NF-κB due to the binding of DZ or EQ, which is translated into decreased TNF-α, COX-2, iNOS, NLRP3, and ASC levels. CONCLUSION:This study establishes that DZ and EQ inhibit LPS-induced inflammatory responses in peritoneal murine macrophages via down-regulation of NO and PGE generation, as well as the inhibition of the canonical inflammasome pathway, regulating NLRP3, and consequently decreasing IL-1β and IL-18 activation.

PURPOSE:Equol is metabolized by intestinal bacteria from soy isoflavones and is chemically similar to estrogen. Dietary habits, such as consumption of soy products, influence equol production. A relationship between glaucoma and estrogen has been identified; here, we investigated the relationship between equol production status and glaucoma in Japan. METHODS:We recruited 68 normal-tension glaucoma (NTG) patients (male to female ratio 26:42, average age 63.0 ± 7.6 years) and 31 controls (male to female ratio 13:18, average age 66.0 ± 6.3 years) from our hospital. All women included were postmenopausal. Urinary equol concentration was quantified with the ELISA method. MD was calculated based on the Humphrey visual field. The association between MD and equol was analyzed with Spearman's rank correlation coefficient. The Mann-Whitney U test was used to compare the equol-producing (> 1 μM) and non-producing (< 1 μM) subjects. We also investigated the association between equol and glaucoma with a logistic regression analysis. RESULTS:There was a significant association between equol and MD (r = 0.36, P < 0.01) in the NTG patients. Glaucoma, represented by MD, was significantly milder in the equol-producing subjects than the non-equol producing subjects (P = 0.03). A multivariate analysis revealed the independent contributions of equol, cpRNFLT, and IOP to MD (P = 0.03, P = 0.04, and P < 0.01, respectively). CONCLUSION:Our results suggest that equol, acting through estrogen receptor-mediated neuroprotective effects, might be involved in suppressing the progression of NTG. This result also adds to evidence that glaucoma may be influenced by lifestyle.