Abstract: BACKGROUND ＆ AIM: To investigate the antioxidative activity of high doses vitamin E(VE) and C(VC) and its effects on DNA oxidative and alkyl damages in rats. MATERIAL AND METHODS: 72 Wistar rats were randomly divided into six groups including control,VC,VE1,VE2,VE1＋VC and VE2＋VC groups. The trial lasted 8 weeks,and urine and blood samples of each rat were collected at the end of the trial. The activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), level of malondialdehyde (MDA) and DNA damage were assessed. RESULTS: Plasma SOD and GSH-Px activities in VE1 group were 425.21 NU/ml and 440.08 U/ml,respectively which were significantly higher than those of the control group while MDA in this group was significantly lower than that of the control. The same antioxidative enzyme activities in VE1＋VC group were significantly lower than that of the VE1 group. Lymphocyte DNA oxidative damage induced by 10 μmol/L H2O2 in VE1 group was significantly lower than those in other groups and O6-methyl guanine (O6-meG) level in this group was 0.89 mg/g creatinine which was significantly lowered by 50.28％,50.00％ compared with that of control group and that of the VE2 group,respectively. CONCLUSION: Relatively high dose VE could effectively increase antioxidative activity and decrease DNA oxidative and alkyl damages. Using the same dose of VE and VC supplements in combination was found to confer no such advantageous effect. Too high dose VE and VC could decrease the genetic stability.

Key words: vitamin E, vitamin C, antioxidation, DNA damage