Abstract: Objective: To observe the effect of zinc threonine on antioxidant activity and function of liver in streptozotocin (STZ)-induced diabetic rats and probe the underlying mechanisms. Methods: Wistar rats were subjected to caudal vein injection of STZ to induce a diabetic model. The model rats were randomly divided into diabetic control group, metformin positive control group, and low-, middle- and high-dosage zinc threonine groups, and normal group. The activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and nitric oxide synthase (NOS) and the content of malondialdehyde (MDA) and nitric oxide (NO) in the liver homogenates of each group were determined after 8 weeks of administration carried out once a day. Meanwhile, the activities of serum ALT and AST and the content of TP were assayed. Results: Compared with the diabetic control group, MDA, NO, SOD, GSH-Px and liver index in the high-dosage zinc threonine group were obviously improved (P <0.05), and the effect of zinc threonine on ALT, AST, AST/ALT and TP were in a dose-dependent manner. Conclusion: Zinc threonine can protect the liver from oxidative damage and improve the liver function of diabetic rats.

Key words: zinc threonine, diabetes mellitus, rat, oxidative stress, liver function