Diabetes is a serious hazard to human health,and its pathogenesis is related to oxidative stress.Hawthorn (Crataegus pinnatifida Bunge) is a fruit-bearing shrub as a medicinal substance,in which total flavonoids from hawthorn leaf (TFHL) have favorable antioxidant properties.To explore the antioxidant effect of TFHL on diabetic mice,84 four-week-old SPF male ICR mice were randomly divided into control group,model control group,DMSO model control group,model groups with high-,medium-and low-dose of TFHL and positive control group,there was no significant difference in body mass among all groups.The mice in each model group were intraperitoneally injected with 1% streptozotocin (STZ) at 150 mg/kg to construct STZ-induced diabetic mice,and the control group were injected with the same amount of sodium citrate solution.After the successful preparation of the model,the patients were given different concentrations of TFHL,or metformin hydrochloride or DMSO or water daily for 28 days.Then,enzyme activities of speroxide dismutase (SOD),glutathione peroxidase (GSH-PX),total antioxidant capacity (T-AOC) and malondialdehyde (MDA) content in serum and liver tissues of mice were measured by the reagent kit method;the expression of antioxidant genes SOD-1,SOD-2,GPX-1 and GPX-4 were detected by Real-time PCR.The results showed that TFHL significantly increased the activities of SOD,T-AOC and GSH-PX in the serum and liver of diabetic mice (P<0.01),and reduced the content of MDA (P<0.01).meanwhile the expression of SOD-1,SOD-2,GPX-1 and GPX-4 genes were increased in the liver of diabetic mice after treated with TFHL.These data suggested that TFHL can improve the oxidative stress in STZ-induced diabetic mice and enhance their antioxidant capacity.