Gentiana kurroo Royle attenuates the metabolic aberrations in diabetic rats; Swertiamarin, swertisin and lupeol being the possible bioactive principles.

Background Gentiana kuroo Royle is a medicinally important plant of north-western Himalayas used for various ailments. In the present study, the plant extracts were investigated for the antidiabetic effects in streptozotocin-induced diabetic rats. Methods The impact of the extracts on serum glucose levels of diabetic rats was compared with reference drug - glibenclamide-treated diabetic rats. Streptozotocin injection was used to induce diabetes in fasted rats. Various biochemical, physiological and histopathological parameters in diabetic rats were observed for assessing the antidiabetic activity. Results The serum glucose concentrations in diabetic rats were significantly lowered by the extracts (methanolic and hydroethanolic at the doses of 250 and 500 mg/kg body weight). Several related biochemical parameters like creatinine, low-density lipoproteins, triglycerides, cholesterol, alkaline phosphatase, serum glutamate oxaloacetate transaminase and serum glutamate pyruvate transaminase were likewise decreased by the concentrates. The extracts also showed reduction in feed and water consumption of diabetic rats when compared with the diabetic control. The extracts were found to demonstrate regenerative/protective effect on β-cells of pancreas in diabetic rats. The methanolic and hydroethanolic extracts also exhibited hypoglycaemic effect in normal glucose-fed rats (oral glucose tolerance tests). LC-MS characterization of this extract showed the presence of these compounds - Swertiamarin, swertisin, lupeol, etc. Conclusions The current study demonstrated the counter diabetic capability of G. kuroo Royle being powerful in hyperglycaemia and can viably ensure against other metabolic deviations created by diabetes in rats. The possible bioactive principles responsible for the antidiabetic activity of G. kurroo Royle are Swertiamarin, swertisin and lupeol.