comparative study of effects of gymnema sylvestre extract, tolbutamide and metformin on blood glucose levels of normoglycaemic and hyperglycemic rabbits

ABSTRACT

The watery extract of the leaves of Gymnema sylvestre was administered in doses of50, 100, 150 and 200 mg/kg body weight to normo-glycaemic and ACTH induced hyperglycaemic rabbits. The blood glucose levels were estimated before and after two, four and six hours of the administration of the extract. The extract exerted a significant [P < 0.001] hypoglycaemic effect in normolglycaemic and hyperglycaemic rabbits. The mean percent decreases in blood glucose levels produced by Gymnema sylvestre in normoglycaemic rabbits were compared with those produced in hyperglycaemic rabbits at various time intervals and the differences were highly significant [P< 0.001]. The maximum decrease in blood glucose, at all dosage levels, in normoglycaemic and hypergylcaemic rabbits was observed at six hours. Gymnema sylvestre extract in a dose of 150 mg/kg produced maximum decrease in blood levels of both normoglycaemic and hyperglycaemic rabbits. The mean percent decreases in blood glucose levels produced by 150 mg/kg of Gymnema sylvestre were compared with those produced by 250 mg/kg of tolbutamide at respective time intervals in normoglycaemic and hyperglycaemic rabbits. In normoglycaemic rabbits, the differences were not significant [P > 0.01]. In hyperglycaemic rabbits, however, the differences were highly significant [P< 0.001]. The mean percent decreases in blood glucose levels, produced by 150 mg/kg of Gymnema sylvestre were also compared with those produced by 250 mg/kg of tolbutamide at respective time intervals in normoglycaemic and hyperglycaemic rabbits. In normoglycaemic rabbits, the differences were not signifiacant [P> 0.01]. In hyperglycaemic rabbits, however, the differences were highly significant [P < 0.001]. From, this study, it may be concluded that extract of Gymnema sylevestre possesses a significant and consistent hypoglycaemic effect in normoglycaemic and hyperglycaemic rabbits. Thus it may be recommended in the treatment of hyperglycaemia due to diabetes mellitus