Ginsenoside­Rg5 induces apoptosis and DNA damage in human cervical cancer cells.

Panax ginseng is traditionally used as a remedy for cancer, inflammation, stress and aging, and ginsenoside­Rg5 is a major bioactive constituent of steamed ginseng. The present study aimed to evaluate whether ginsenoside­Rg5 had any marked cytotoxic, apoptotic or DNA­damaging effects in human cervical cancer cells. Five human cervical cancer cell lines (HeLa, MS751, C33A, Me180 and HT­3) were used to investigate the cytotoxicity of ginsenoside­Rg5 using a 3­(4,5­dimethylthiazol­2­yl)­2,5­diphenyltetrazolium bromide assay. Additionally, the effects of ginsenoside­Rg5 on the apoptosis of HeLa and MS751 cells were detected using DNA ladder assays and flow cytometry. DNA damage was assessed in the HeLa and MS751 cells using alkaline comet assays and by detection of γH2AX focus formation. The HeLa and MS751 cells were significantly more sensitive to ginsenoside­Rg5 treatment compared with the C­33A, HT­3 and Me180 cells. As expected, ginsenoside­Rg5 induced significant concentration­ and time­dependent increases in apoptosis. In addition, ginsenoside­Rg5 induced significant concentration­dependent increases in the level of DNA damage compared with the negative control. Consistent with the comet assay data, the percentage of γH2AX­positive HeLa and MS751 cells also revealed that ginsenoside­Rg5 caused DNA double­strands to break in a concentration­dependent manner. In conclusion, ginsenoside­Rg5 had marked genotoxic effects in the HeLa and MS751 cells and, thus, demonstrates potential as a genotoxic or cytotoxic drug for the treatment of cervical cancer.