Effect of rapeseed peptide on DNA damage and apoptosis in Hela cells.

Rapeseed peptide (RSP), obtained by hydrolyzing rapeseed protein, has anticancer activity. In this study, the effects of RSP on proliferation rate, morphological changes, DNA damage, cell cycle distribution and apoptosis in human cervical carcinoma (Hela) cells were investigated. RSP treatment at a concentration of 640 mg/L for 4 days inhibited Hela cell proliferation significantly, as determined by the MTT assay. We observed a dose-dependent increase in cytotoxicity induced by RSP at 20-640 mg/L. After 4 days of 320 mg/L RSP treatment, typical apoptotic changes were observed by transmission electron microscopy (TEM). Using the comet assay, we found dramatic comet tails, indicating DNA damage by RSP (20-640 mg/L). Moreover, RSP treatment caused inhibition of Hela cell growth, with cycle arrest in the S phase and apoptosis induction. Taken together, the results suggested that rapeseed peptide could be a potential antitumor compound with an apoptotic mode of action.