Berberine inhibits the proliferation of prostate cancer cells and induces G0/G1 or G2/M phase arrest at different concentrations

Prostate cancer is the second most common disease of the male reproductive system. Berberine is a quaternary ammonium salt that is extracted from plants. The aim of the current study was to explore the antitumor activity of berberine in prostate cancer cells and identify the underlying mechanism of its effects. PC3 human and RM-1 mouse prostate cancer cells were treated with increasing concentrations of berberine, followed by analysis of the cell viability with an MTT assay. The results demonstrated that berberine markedly inhibited the proliferation of PC3 and RM-1 cells, and that the inhibitory effects to PC3 and RM-1 were enhanced in a concentration- and time-dependent manner. Flow cytometry was used to analyze the cell cycle of PC3 human prostate cancer cells, and the results demonstrated that G(0)/G(1) phase arrest was induced following treatment with 10 mu M berberine (P<0.05). However, with an increased concentration of berberine (50 mu M) the survival rate of PC3 cells at the G(2)/M phase was significantly increased compared with the cells treated with 10 mu M berberine, which suggests that different cell cycle signaling pathways were activated when PC3 cells were treated with low and high concentrations of berberine. Thus, clarifying the mechanism underlying these effects in prostate cancer may provide novel molecular targets for prostate cancer therapy.