The protective effect of Yi-Qi-Yang-Yin-Ye, a compound of traditional Chinese herbal medicine in diet-induced obese rats

The present study was undertaken to determine the effect of Yi-Qi-Yang-Yin-Ye (Y-Q-Y-Y-Y), a compound of Traditional Chinese Herbal Medicine, on insulin resistance (IR) in the diet-induced obese rat model induced by intravenous injection with a low dose of streptozotocin and fed a high fat and high caloric diet. Y-Q-Y-Y-Y (2, 4, 8 g/kg) was administered via gavage daily for 4 weeks. The results showed that Y-Q-Y-Y-Y treatment decreased the levels of body weight, total cholesterol (TC), triglycerides (TG), low density lipoprotein-cholesterol (LDL-C), free fatty acid (FFA), insulin (INS) and fast blood glucose (FBG) and increased the level of high density lipoprotein-cholesterol (HDL-C) in the diet-induced obese rats. Glucose tolerance was improved in the diet-induced obese rats treated with Y-Q-Y-Y-Y as well as GIR (glucose infusion rate) in the hyperinsulinemic euglycemic clamp experiment compared to the model control rats (p < 0.01). Moreover, treatment with Y-Q-Y-Y-Y up-regulated glycogen contents in both liver and skeletal muscle and increased insulin receptor amounts on the erythrocytes surface as assessed by using (125)I-labeled auto-antibodies against insulin receptors. Taken together, our data suggested that Yi-Qi-Yang-Yin-Ye ameliorates insulin resistance in the diet-induced obese rats.