Abstract: Objective To explore the different regulatory effects of ginsenoside Rg3 on the proliferation of prostate cancer cells PC3 and DU145. Methods PC3 and DU145 cells were cultured in vitro and treated with ginsenoside Rg3 at 100 µmol/L. Then CCK-8 assay was performed to evaluate the proliferation of cells. Reactive oxygen species (ROS) levels were detected using DCFH-DA staining in DU145 cells treated with DMSO or ginsenoside Rg3. JC-1 staining was performed to investigate the depolarization of mitochondrial membrane in PC3 and DU145 cells treated with ginsenoside Rg3. Differential expression of antioxidant proteins in PC3 and DU145 cells were analyzed by RT-PCR and Western blot assay. Results CCK-8 assay showed that the proliferation of PC3 cells was significantly inhibited by 100 µmol / L ginsenoside Rg3 while no inhibitory effect was observed on DU145 cells. Results of DCFH-DA staining assay showed that the ROS levels in DU145 cells and PC3 cells were up-regulated by ginsenoside Rg3. Furthermore, results of JC-1 assay demonstrated that ginsenoside Rg3 induced the depolarization of mitochondrial membrane both in PC3 and DU145 cells. The results of RT-PCR and Western blot assay indicated that the expressions of glutathione peroxidase-1 (GPX-1) and superoxide dismutase 2 (SOD2) were higher in DU145 cells compared to those of PC3 cells. Conclusion Ginsenoside Rg3 shows different regulatory effects on the proliferation of PC3 and DU145 cells, which may be related to the differential expression of antioxidant proteins in the two cell lines.

Key words: prostatic neoplasms, reactive oxygen species, membrane potential, mitochondrial, glutathione peroxidase, superoxide dismutase, ginsenoside Rg3