Abstract: Objective To investigate the effect of berberine on ferroptosis in prostate cancer cells and its mechanism. Methods Prostate cancer DU145 and PC⁃3 cells were cultured in vitro, and the effects of berberine with different concentrations (1.560, 3.125, 6.250, 12.500, 25.000, 50.000, 100.000 μmol/L) on the proliferation ability of prostate cancer cells were evaluated by CCK⁃8 assay, and the half⁃inhibitory concentration (IC50) were calculated. The levels of glutathione (GSH), cysteine, reactive oxygen species (ROS), and Fe2+ in both DU145 and PC⁃3 cells were determined by GSH detection assay kit, cysteine assay kit, DCFH⁃DA fluorescent probe assay, and the fluorescent probe, respectively. qRT⁃PCR was performed to detect the expression levels of ferroptosis⁃related genes (GPX4, COX2, FTH1 and SLC7A11). Results Berberine at various concentrations inhibited the proliferation abilities of DU145 and PC⁃3 cells in a concentration⁃dependent way (all P<0.05) , with IC50 values of 19.94 μmol/L and 20.18 μmol/L, respectively. The ferroptosis inhibitor Ferrostatin1 (Fer⁃1) reversed the inhibitory effect of berberine (20 μmol/L) on cell proliferation in DU145 and PC⁃3 cells (all P<0.001), whereas cell apoptosis and pyroptosis inhibitors could not restore cell viability. Treatment with berberine at the concentration of 20 μmol/L significantly decreased the levels of GSH and cysteine in DU145 and PC⁃3 cells (all P<0.001), and increased the levels of lipid ROS and Fe2+ (all P<0.001). However, the Fer⁃1 could reverse berberine⁃induced intracellular lipid ROS level and Fe2+ level (all P<0.001), and restored the levels of GSH and cysteine (all P<0.001). In addition, berberine significantly down⁃regulated the expression levels of SLC7A11 and GPX4 in DU145 and PC⁃3 cells (all P<0.05), while up⁃regulated the expression levels of COX2 and FTH1 (all P<0.01). Overexpression of SLC7A11 reversed the promotive effect of berberine on ferroptosis in prostate cancer cells (all P<0.001). Conclusions Berberine promotes intracellular lipid ROS accumulation and up⁃regulation of Fe2+ levels in prostate cancer cells by inhibiting SLC7A11 expression to induce ferroptosis.

Key words: Prostate cancer, Berberine, Ferroptosis, Lipid oxidation