Abstract: Objective To develop a rat model of type 2 diabetic mellitus and study the protective effects of peanut oil on improvement and treatment of type 2 diabetic mellitus.Methods After 2 months of high-fat food feeding,type 2 diabetic mellitus models were prepared with low dose STZ intraperitoneal injection in 8 weeks old SD rats.Then they were treated with different dose of peanut oil.One month later,the rats were examined with Morris water maze test and then the levels of serum lipids,serum insulin and blood glucose were measured.Results The rat models were characterized by hyperglycemia,hyperlipemia and hyperinsulinemia which resembled the clinical phenotype of type 2 diabetes.The results of Morris water maze test : there was no difference among 4 groups(P>0.05).The levels of blood glucose、serum insulin and serum lipids were significantly lower in 5 mL peanut oil group than those of in diabetic model group(P<0.05).Conclusion The data of Morris water maze test suggests that there is no cognitive impairment in early stage of type 2 diabetic mellitus.The decrease of hyperglycemia,hyperlipemia and hyperinsulinemia with peanut oil indicates that peanut oil can improve and treat the type 2 diabetic mellitus.

Key words: type 2 diabetic mellitus, peanut oil, triglyceride, insulin resistance