| Objective: Through the observation of lignans to inhibit the hyperplasia of prostate gland in rats in vivo, we aimed to explore whether enterolactone, the metabolite of lignans could activate the G protein coupled estrogen receptor(G Protein-Coupled estrogen receptor 1/GPER) pathway and inhibit the proliferation of WPMY-1 cells in vitro.Methods: 32 male Wistar rats(about 200g) were randomly divided into SDG/TP treatment group, finasteride/TP treatment group, model group(TP alone) and saline blank, 8 rats in each group. Continuous subcutaneous injection of testosterone propionate(TP, 5 mg/kg/d) for 28 days was employed to establish BPH in male Wistar rats. SDG(40mg/Kg/d) and finasteride(0.1mg/Kg/d) were treated by intragastric administration; the treatment time was 4 weeks; at the end of the experiment, we obtained the rat prostate, to calculate prostate exponent, to observe morphological changes in prostate tissues of prostate tissue using HE staining and to check the expression of GPER by immunofluorescence. Human prostate stromal cells were cultured in vitro(WPMY-1), SDG metabolites enterolactone(ENL) at 1μΜ and 5μΜ, 10μΜ and 20μΜ concentration were used to treat cells for 24 h and MTT assay was used to examine cell proliferation; In addition, 20μΜ ENL and GPER specific agonist G1 was used to treat WPMY-1 cells for 24 h to determine cell cycle. Meanwhile, proteins were extracted and the expression of GPER, p-ERK, p53, p21, cyclin D1 were detected by Western blot.Results:(1)Comparing with the model group, prostate index of SDG treatment group was significantly reduced; while comparing with finasteride group, there was no difference. Prostate HE staining showed that in SDG group, the thickness of pseudostratified epithelial cells and stromal cells decreased, glandular morphology generally recovered. Immunofluorescence staining experiments further showed that GPER receptor levels in prostate cell membrane of SDG treatment group were significantly increased.(2)The proliferation of human prostate stromal cell line WPMY-1 is inhibited by ENL and cell cycle is arrested in G1 phase. The expression of p-ERK,P53, P21 was increased, and cell cycle protein CyclinD1 was reduced after ENL treatment.Conclusions:(1) Lignan suppressed benign prostatic hyperplasia both in vitro and in vivo;(2) ENL inhibited WPMY-1 cell growth by the induction of G0/G1 cell cycle arrest. ENL-induced cell cycle arrest may be mediated by the activation of GPER/ERK pathway and subsequent upregulation of p53 and p21, downregulaton of cyclin D1. |
