Effects of Chinese herbal medicine Yiqi Zengmin formula on expression of glucose transporter 4 in skeletal muscle in type 2 diabetic rats

OBJECTIVE: To investigate the effects of traditional Chinese compound recipe Yiqi Zengmin (YQZM) formula on expression of glucose transporter 4 (GLUT4) in skeletal muscle of rats with type 2 diabetes induced by high-fat diet combined with low-dose-streptozotocin injection. METHODS: Fifty male rats were randomly divided into two groups: model group fed with high-fat diet (n=40) and control group (n=10). After 4-week feed of high-fat diet, the rats of the model group were injected with streptozotocin at a dose of 35 mg/kg. Rats with plasma glucose over 16.67 mmol/L were randomly divided into 4 groups: diabetic model group, YQZM group, rosiglitazone group and losartan group and were treated with water, YQZM, rosiglitazone or losartan respectively by oral administration for 8 weeks. The expression of GLUT4 protein in the cytoplasm and the plasma membrane of isolated rats' skeletal muscles were detected by Western blotting. RESULTS: The expression of GLUT4 in the plasma membrane was more than that in the cytoplasm in skeletal muscle tissues of the normal rats, while the expression of GLUT-4 in the plasma membrane was less than that in the cytoplasm in skeletal muscle tissues of the type 2 diabetic rats. YQZM formula enhanced GLUT4 translocation from the cytoplasm to the plasma membrane in skeletal muscle tissues, similar to rosiglitazone. CONCLUSION: YQZM formula can enhance GLUT4 translocation from the cytoplasm to the plasma membrane in skeletal muscle tissues, and displays the insulin sensitization characteristic of rosiglitazone.