Sub-chronic oral administration of the ethanolic extracts of dried Terminalia chebula mature fruits in streptozotocin (STZ)-induced type 2 diabetes mellitus (T2DM) model of Long-Evans (L-E) rats improve glycemic, lipidemic and anti-oxidative status

Mechanisms of the long known anti-diabetic effects exerted by the fruits of Terminalia chebula are not yet clearly understood. Here, we sought to get a biochemical view of the mechanisms. First, a single injection of streptozotocin (STZ) was given (50 mg/Kg of body weight, bw) to 48 hours old pups of Long-Evans (L-E) rats intraperitoneally (ip) to induce type 2 diabetes (T2DM). At the age of 3 months, a total of twenty male L-E rats, having T2DM were included in this study and divided into 4 groups (n = 5, for each group). T2DM was confirmed by a standard oral glucose tolerance test (OGTT). Next, T2DM rats were orally administered with a single dose of 80% ethanolic extracts of either the fresh or dried fruits for consecutive 28 days. Water and glibenclamide were used as negative and positive control, respectively. Administration of dried(p = 0.001) and fresh (p = 0.02) fruit extracts significantly reduced the fasting serum glucose level as compared to that of water control. Fasting serum lipid profile show that administration of both fresh and dried fruit extracts caused a significant reduction of triglycerides (p = 0.016), total cholesterol (p = 0.001) and low density lipoprotein-cholesterol (p = 0.001). Examinations of antioxidant potential profile demonstrate that dried fruit extracts only decreased the levels of plasma MDA in T2DM rats to a notable extent (62%). Although the fruit extracts could not improve the levels of serum insulin, but increased the liver glycogen content to a remarkable extent (240%). This study indicates that sub-chronic administration of the ethanolic extracts of dried Terminaria chebula mature fruits improve glycemic, lipidemic and anti-oxidative status in T2DM male L-E rats and that the hypoglycemic action may be mediated by an extra-pancreatic mechanism.