关键词: 绞股蓝, DNA损伤, 彗星电泳, O6-甲基鸟嘌呤

Abstract: BACKGROUND ＆ AIM: To investigate the effects of Gynostemma pentaphyllum (GP) extract on DNA oxidative and alkylating damages. MATERIAL AND METHODS: Adult Wistar rats received 100 mg/kg D-galactose subcutaneous injection each day to build the aging model. There was also a control group. These groups of rats were fed with fully compounded diet which was supplemented with different doses of Gynostemma pentaphyllum extract or vitamin E, C(VE＋C) for 8 weeks. Whole blood was collected at the end of the trial.Spontaneous and induced oxidative DNA damages were analyzed by SCGE. Urine was collected before the end of the trial. Urinary O6-MeG was analyzed by high performance capillary zone electrophoresis. RESULTS: There was no statistical difference in spontaneous DNA damage among 6 groups(P>0.05). But less oxidative DNA damage induced by 5, 10, 25 μmol/L H2O2 were found in the groups supplemented with Gynostemma pentaphyllum extract and the VE＋C group than in the aging group(P<0.05). When supplemented with higher dose of Gynostemma pentaphyllum extract, DNA damage showed no significant differences compared with the control group and VE＋C group. The level of urinary O6-MeG in the aging group was not higher than that in the other groups (P>0.05). CONCLUSION: D-galactose could induce DNA oxidative damage while it had no effect on DNA alkylating damage. When Gynostemma pentaphyllum extract was given to aging rats, the oxidative DNA damage induced by H2O2 could be effectively decreased and the alkylating DNA damage showed no change.

Key words: Gynostemma pentaphyllum, DNA damage, SCGE, O6-MeG