Standardized Extract from Enicostemma littorale Ameliorates Post-prandial Hyperglycaemia in Normal and Diabetic Rats

Abstract

Enicostemma littorale Blume (Gentianaceae) is traditionally used medicinal plant. It is locally known as Chota Chirata. It is used for the treatment of various ailments including diabetes in Indian subcontinent. Its main constituent is a secoiridoid glycoside namely swertiamarin. The aim of current study was to evaluate swertiamarin-rich fraction of E. littorale in controlling post prandial hyperglycemia through the inhibition of carbohydrate metabolizing enzymes in in-vitro and in-vivo studies. Standardized extract of E. littorale (SEL) was prepared by ultrasound assisted extraction (UAE) and its swertiamarin content was estimated by HPTLC. The content of swertiamarin was found to be 13.62 ± 1.46 (% w/w) in SEL on dry weight basis. The effect on α-amylase and α-glucosidase was evaluated in-vitro. It was followed by antihyperglycemic studies in carbohydrate challenged normal and STZ-induced diabetic rats. SEL was found to inhibit α-amylase and α-glucosidase with IC50 values of 12.29 ± 0.31 mg/ml and 9.42 ± 0.61 mg/ml, respectively. In-vivo studies with normal and diabetic rats revealed that the treatment with SEL (200 mg/kg b.w.), twenty minutes prior to carbohydrate challenge produced significant (p < 0.01) blood glucose lowering effect in both the models. The present study clearly indicates the beneficial effects of swertiamarin-rich fraction of E. littorale in controlling post prandial hyperglycemia.