LAUSR

ABSTRACT Green tea is among the most popular beverages in the world and is an important source of phytoestrogens. Epigallocatechin‐3‐gallate (EGCG) is the major polyphenol in green tea. The aim of this study was to investigate the anti‐benign prostatic hyperplasia (BPH) activity and underling mechanisms of EGCG in testosterone‐induced BPH rats and in BPH‐1 cells. Prostatic levels of oxidative stress and inflammation makers, as well as angiogenesis related growth factors were measured. Additionally, the prostatic levels of sex hormonal mediators (androgen receptor (AR), estrogen receptor (ER)‐&agr; and ER‐&bgr;), hypoxia‐inducible factor (HIF)‐1&agr;, transforming growth factor‐&bgr;1 (TGF‐&bgr;1), type I TGF‐&bgr; receptor (TGF‐&bgr;RI), Smad3, phosphorylation‐Smad3 (p‐Smad3), epithelial–mesenchymal transition (EMT) markers (E‐cadherin, collagen‐I, fibronectin and &agr;‐SMA) and microRNA (miR)‐133a/b were analyzed by immunohistochemistry assay, western blot and/or quantitative RT‐PCR. It was observed that EGCG attenuated the prostatic oxidative stress and inflammatory microenvironment, ameliorated prostatic hyperplasia and collagen deposition, reduced the levels of angiogenesis related growth factors, inhibited the over‐expression of AR, ER‐&agr;, HIF‐1&agr;, TGF‐&bgr;1, TGF‐&bgr;RI and p‐Smad3, enhanced the expression of ER‐&bgr;, increased the levels of miR‐133a/b, as well as relieved prostatic EMT in rats. Both HIF‐1&agr; inhibitor and EGCG decreased the expression of HIF‐1&agr; and TGF‐&bgr;1, as well as attenuated EMT in BPH‐1 cells. It indicated that EGCG could attenuate testosterone‐induced BPH and fibrosis. Graphical abstract Figure. No Caption available. HighlightsEGCG ameliorated prostatic hyperplasia and collagen deposition.EGCG regulated prostatic hormonal mediators.EGCG inhibited prostatic oxidative stress and inflammation.EGCG modulated the prostatic TGF‐&bgr;/Smad pathway.EGCG attenuated prostatic epithelial‐mesenchymal transition.