ABSTRACT
Objective To observe the hypoglycemic mechanism of total saponins of Momordica charantia (MC) in type 2 diabetes mellitus (DM) rats. Methods Among the selected 60 male Specific Pathogen Free (SPF)rats, 8 were random- ly chosen as control group, while others were fed with high fat and high glucose diet following streptozotocin injection from caudal vein 8 weeks after to construct type 2 DM models. After the DM models were successfully built, rats were then ran- domized into five groups: DM control group (n=8), the metformin group (n=8) and three groups of total saponins of MC with different dosage (n=8 in each group). The total saponins of MC groups include DM rats administrated with total saponins of MC 100, 200, 400 mg/(kg·d) for 8 weeks, the metformin group include DM rats administrated with metformin 50 mg/(kg·d) for 8 weeks. At the end of the experiment, the fasting blood glucose and insulin were examed. At the same time, a part of pan- creas islet, liver and skeletal muscle were preserved. The pancreas islet structure, the hepatic glycogen and Glucose trans- porter 4 (GLUT4) expression were observed by electron microscope, glycogen dyeing and immunoblot respectively. Results After 8 weeks treatment, compared to type 2 DM control group, fasting blood glucose and insulin values in MC groups were reduced more obviously. However, skeletal muscle GLUT4 expression level, insulin granules and hepatic glycogen increased obviously in MC groups. Conclusion Total saponins of MC has hypoglycemic effect. It’s mechanisms maybe include pro- moting the hepatic glycogen synthesis, inhibiting the hepatic glycogen decomposition and promoting insulin sensitivity by in- creasing peripheral tissue’s GLUT4 expression.