Luteolin, a flavonoid, as an anticancer agent: A review. Imran Muhammad,Rauf Abdur,Abu-Izneid Tareq,Nadeem Muhammad,Shariati Mohammad Ali,Khan Imtiaz Ali,Imran Ali,Orhan Ilkay Erdogan,Rizwan Muhammad,Atif Muhammad,Gondal Tanweer Aslam,Mubarak Mohammad S Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie Many food-derived phytochemicals and their derivatives represent a cornucopia of new anti-cancer compounds. Luteolin (3,4,5,7-tetrahydroxy flavone) is a flavonoid found in different plants such as vegetables, medicinal herbs, and fruits. It acts as an anticancer agent against various types of human malignancies such as lung, breast, glioblastoma, prostate, colon, and pancreatic cancers. It also blocks cancer development in vitro and in vivo by inhibition of proliferation of tumor cells, protection from carcinogenic stimuli, and activation of cell cycle arrest, and by inducing apoptosis through different signaling pathways. Luteolin can additionally reverse epithelial-mesenchymal transition (EMT) through a mechanism that involves cytoskeleton shrinkage, induction of the epithelial biomarker E-cadherin expression, and by down-regulation of the mesenchymal biomarkers N-cadherin, snail, and vimentin. Furthermore, luteolin increases levels of intracellular reactive oxygen species (ROS) by activation of lethal endoplasmic reticulum stress response and mitochondrial dysfunction in glioblastoma cells, and by activation of ER stress-associated proteins expressions, including phosphorylation of eIF2α, PERK, CHOP, ATF4, and cleaved-caspase 12. Accordingly, the present review article summarizes the progress of recent research on luteolin against several human cancers. 10.1016/j.biopha.2019.108612

Flavonoids showed anticancer effects on the ovarian cancer cells: Involvement of reactive oxygen species, apoptosis, cell cycle and invasion. Tavsan Zehra,Kayali Hülya Ayar Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie Flavonoids have been recently identified as a potential anticancer agent against various human epithelial cancers. In this study, the elucidation of mechanisms underlying the anticancer effects of the apigenin, luteolin and myricetin will be new knowledge about preventive strategies against epithelial ovarian cancer in which the effect of flavonoids is still unclear. The cytotoxic effect of flavonoids was assessed by MTT analysis of the ovarian cancer cells (A2780, OVCAR-3 and SKOV-3) in comparison to the ovarian epithelial cells (OSE). The intracellular reactive oxygen species (ROS) generation, malondialdehyde (MDA) and protein carbonyl levels, caspase-3 and -9 activities were evaluated using fluorescence spectrometry. Apoptosis and cell cycle arrest, and cell invasion were measured by flow cytometry and Boyden chamber assay, respectively. MTT analysis showed that flavonoids selectively decreased the cell viability of cancer cells. Furthermore, the intracellular ROS generation was induced or scavenged by flavonoids depending on the structural differences. The flavonoids increased MDA levels due to the disruption of the membrane. Caspase activities indicated that flavonoids activated the extrinsic apoptotic pathway when ROS was scavenged. In contrast, the induced intracellular ROS generation resulted in the activation of the intrinsic apoptotic pathway. In addition, the cell cycle was arrested in different cell cycle phases and cell invasion on the collagen was disrupted by flavonoids. The anticancer activities of apigenin, luteolin and myricetin were attributed to the alterations of ROS signaling, and as well as the induction of apoptosis, cell cycle arrest and abrogation of the invasion. The present study may uncover new strategies for ovarian cancer therapy. 10.1016/j.biopha.2019.109004

Effects of dietary flavonoids, luteolin, and quercetin on the reversal of epithelial-mesenchymal transition in A431 epidermal cancer cells. Lin Yung-Sheng,Tsai Pei-Hsun,Kandaswami Chithan C,Cheng Chia-Hsiung,Ke Ferng-Chun,Lee Ping-Ping,Hwang Jiuan-Jiuan,Lee Ming-Ting Cancer science Highly invasive A431-III cells, which are derived from parental A431-P cells, were originally isolated by three successive passages through a Boyden chamber using a Matrigel-coated membrane support. The greater invasion potential shown by A431-III cells was due to their increased ability to spread/migrate, which was associated with enhanced MMP activity. The tumor progression events evoked by A431-P cells compared to A431-III cells may help identify useful strategies for evaluating the epithelial-mesenchymal transition (EMT) and these cell lines could be a reliable model for evaluating tumor metastasis events. Using this approach, we evaluated the effects of luteolin and quercetin using the A431-P/A431-III EMT model. These flavonoids reversed cadherin switching, downregulated EMT markers, and nullified the invasion ability of A431-III cells. Overexpression of MMP-9 resulted in induction of the EMT in A431-P cells and this could be reversed by treating with luteolin or quercetin. Cotreatment of A431-P and A431-III cells with epidermal growth factor (EGF) plus luteolin or quercetin resulted in a more epithelial-like morphology, led to reduced levels of EGF-induced markers of EMT, and caused the restoration of cell-cell junctions. E-cadherin was decreased by EGF, but increased by luteolin and quercetin. Our results suggest that luteolin and quercetin are potentially beneficial agents that target and prevent the occurrence of EMT in epidermal carcinoma cells. These chemicals also have the ability to attenuate tumor progression in A431-III cells. Luteolin and quercetin show inherent potential as chemopreventive/antineoplastic agents and do this by abating tumor progression through a reversal of EMT. 10.1111/j.1349-7006.2011.02035.x