Abstract: Objective: To study the effects of poria cocos complex extract on the levels of blood glucose and blood lipid and the antioxidant capacity in the rats with type 2 diabetes mellitus(T2DM), and to elucidate its mechanism. Methods: After 65 male SPF SD rats were adaptively fed for 1 week,10 rats were randomly selected as control group; the rest of rats were fed with high glucose and fat and intraperitoneally injected with STZ (30 mg·kg^-1) to establish the T2DM rat models. The model rats were randomly divided into model group, metformin group,and low, and medium and high doses of poria cocos compound extract groups. The rats in low, medium and high doses of poria cocos compound extract groups were administered with different doses (1.5, 3.0 and 6.0 g·kg^-1) of poria cocos compound extract by gavage for 4 weeks, and the rats in control group and model group were given the same volume of double distilled water for 4 weeks. The body weights and the levels of fasting blood glucose (FBG) of the rats in various groups were detected, the levels of serum insulin (INS), glucagon (GC), triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and malondialdehyde (MDA) and the activities of superoxide dismutase (SOD) of the rats in various groups were measured, and the homeostasis model was used to evaluate the insulin resistance index (HOMA-IR). Results: Compared with control group, the body weight of the rats in model group was significantly reduced(P<0.05), the FBG level was significantly increased (P<0.05), the serum GC, TG, TC, LDL-C and MDA levels and HOMA-IR were significantly increased(P<0.05), and the serum INS and HDL-C levels and the SOD activity were significantly decreased(P<0.05). Compared with model group, the body weights of the rats in low, medium and high doses of poria cocos compound extract groups were significantly increased(P<0.05), the FBG levels were significantly decreased(P<0.05), the serum GC, TG, TC, LDL-C and MDA levels and HOMA-IR were significantly decreased(P<0.05),and the serum INS and HDL-C levels and the SOD activities were significantly increased(P<0.05). Conclusion: Poria cocos compound extract can reduce the level of FBG, regulate lipid metabolism disorder and resist the oxidation in the T2DM rats, and significantly improve insulin resistance.

Key words: poria cocos compound extract, streptozotocin, fasting blood glucose, lipid metabolism, antioxidant, insulin resistance