Gambogic acid inhibits cell proliferation and induces apoptosis of human prostate cancer PC-3 cells in vitro

Objective: To study the effects of gambogic acid (GA) — an effective component extracted from gamboges on cell proliferation and apoptosis of human prostate cancer PC-3 cells. Methods: Prostate cancer PC-3 cells were treated with different concentrations of GA for 24 h in vitro. The cell proliferation was assessed by CCK-8 assay. The apoptosis was analyzed by using AO/EB double staining and flow cytometry (FCM). The expression changes of apoptosis-related proteins such as P53, Bax and Bcl-2 in PC-3 cells were evaluated by Western blotting. Results: As compared with the untreated control group, GA could not only suppress the cell proliferation of PC-3 cells, but also induce the apoptosis in a dose-dependent manner (P0.05). CCK-8 assay revealed that the proliferation of PC-3 cells was significantly inhibited when the concentration of GA was more than 1 μmol/L. AO/EB double staining showed that the nuclei became more dense and more intense orange in PC-3 cells treated with GA as compared with the untreated control PC-3 cells. Apoptosis peak was observed after treatment with GA by FCM. The expression levels of P53 and Bax were up-regulated whereas the expression level of Bcl-2 was down-regulated by GA. Conclusion: GA can significantly suppress the cell proliferation and also induce the apoptosis of human prostate cancer PC-3 cells.