ABSTRACT
Antihyperglycemic potential of hyperin at 25 and 50 mg/kg doses for 30 days to streptozotocin induced diabetic rats has been reported. In oral glucose tolerance test, hyperin treated rats showed a significant reduction in blood glucose level after 120 min. It was found that hyperin exhibited dose dependent and significant antihyperglycemic activity in streptozotocin induced diabetic rats which were nearly similar with standard drug glybenclamide. Activities of glucose-6-phosphatase, fructose-1,6-bisphosphatase, glycogen phosphorylase, glycosylated haemoglobin and level of serum urea and creatinine were significantly decreased in hyperin supplemented diabetic rats, dose dependently. Activities of hexokinase and glycogen synthase were increased with augmentation in liver glycogen, insulin and haemoglobin content in hyperin treated diabetic rats. General hematological parameters did not show any significant change in hyperin treated diabetic rats hence it is safe at these doses. Histopathological studies showed significant morphological changes in pancreatic β-cells of streptozotocin induced diabetic rats. A decreased number of secretory granules of β- cells were observed in diabetic rats and these pathological abnormalities were normalized after treatment with hyperin and standard drug glybenclamide. Further, hyperin decreases significant in serum total cholesterol, triglyceride, low density lipoprotein, very low density lipoprotein levels coupled with elevation of high density lipoprotein in diabetic rats. These results suggest that hyperin has a pivotal role in blood glucose level in streptozotocin induced hyperglycemia by improving the function of pancreatic islets and increasing glycolysis and decreasing gluconeogenesis.