Abstract: AIM: To explore the oxidant-antioxidant status and levels of mononuclear cells ( PBMCs) oxdative DNA damage in patients with type 2 diabetes mellitus( T2DM) , and to value the effect of resveratrol on peripheral blood mononuclear cells oxidative DNA damage in T2DM patients in vitro.METHODS: The DNA damages in PBMCs of 39 T2DM patients with vascular complication,and 29 T2DM patients without complication were detected by single cell gel electrophoresis ( the comet percentage).The levels of plasma total antioxidative capacity(TAC) , the contents of plasma malondialdehyde (MDA) and plasma thiol grouP( SH) were measured.The effect of resveratrol on DNA damage of T2DM patients were investigated in vitro.In addition, 26 healthy subjects were studied as a control grouP.RESULTS: The comet percentage of PBMCs and the contents of plasma MDA in T2DM patients without complication were all significantly higher than that in healthy controls ( P<0.01).The levels of plasma TAC and the contents of plasma thiol grouPin T2DM patients without complication were all remarkably lower than that in healthy controls ( all P<0.01).The comet percentage of PBMCs and the contents of plasma MDA in T2DM patients without complication were significantly lower than that in T2DM patients with vascular complication( P<0.05) , and the levels of plasma TAC in T2DM patients without complication were significantly higher than that in T2DM patients with vascular complication( P<0.05).There were positively correlations between the comet percentage of PBMCs and the contents of plasma MDA in T2DM patients without complication and T2DM patients with vascular complication( r =0.446, P<0.05 ;r =0.504, P<0.01) ;and there were nega-tively correlations between the comet percentage of PBMCs and the contents of plasma TAC in the two groups( r =-0.418, P<0.05 ;r =-0.399, P<0.05).The comet percentage of PBMCs of patients were reduced by 10μmol·L^-1 resveratrol at 4 hours in vitro ( P<0.05).CONCLUSION: There are oxidant-antioxidant unbalance and oxidative DNA damage in T2DM patients, particularly in the patients with vascular complication.Oxidative stress is probably involved in pathogenesis of diabetic vascular complication.Resveratrol can reduce the oxdative DNA damage of PBMCs in patients with T2DM in vitro.Antioxidants supplementation may benefit the prevention of diabetic vascular complication.

Key words: type 2 diabetes mellitus, oxidative stress, DNA damage, resveratrol