Hypoglycemic and antihyperglycemic activity of polyherbal formulation in normoglycemic and Streptozotocin-induced diabetic rats

Abstract

Aim: This study was carried out to investigate the hypoglycemic effects and antihyperglycemic activity of polyherbal (PH) formulation in normal and glucose-loaded and streptozotocin (STZ)-induced diabetic rats. Materials and Methods: PH formulation was tested for hypoglycemic activity for 4 h in normoglycemic rats, oral glucose tolerance test (OGTT) (2 h), and antihyperglycemic activity (28 days) in non-diabetic and STZ-induced diabetic rats.Results and Discussion: PH formulation at 200 and 400 mg/kg doses significantly (P < 0.01) reduced fasting glucose level in normal rats and similar to standard drug glibenclamide. The blood glucose reduction was greatest 32.56% for glibenclamide followed by 32.37% for PH (400 mg/kg) and 26.61% for PH (200 mg/kg), respectively. For OGTT, a significant (P < 0.001) plasma glucose lowering effects of PH (400 mg/kg) followed by PH (200 mg/kg) treated group was observed at all time intervals. Blood glucose lowering was more pronounced for diabetic rat given PH (400 mg/kg) followed by PH (200 mg/kg). Blood glucose levels were significantly lower (P < 0.001) in diabetic rat (STZ), treated with glibenclamide, and the two dose levels of PH up to 4 weeks. At 28 days, blood glucose reduction was greatest 67.48% for PH (400 mg/kg) followed by 62.27% for glibenclamide and 59.26% for PH (200 mg/kg). When compared to non-diabetics, liver glycogen levels in the untreated diabetic group were significantly lower (P < 0.01). Liver glycogen levels increased 2.3-fold in the glibenclamide-treated rats. Similarly, glycogen levels were increased significantly (P < 0.01) by 1.9- and 2.3-fold in PH (200 and 400 mg/kg)-treated groups, respectively. Conclusion: The treatment with PH (400 mg/kg) dose has shown a marked improvement in histological condition, as compared to diabetic control. These findings suggest that this PH formulation may be a potential source for the development of new antidiabetic drug.