ANTIHYPERGLYCEMIC ACTIVITY OF CHARANTIN-RICH EXTRACT FROM THE FRUITS OF Momordica charantia Linn. IN in vitro AND in vivo STUDIES

Momordica charantia Linn. (bitter gourd) fruit is one of the common vegetable consumed in India; and is also traditionally used for the management of blood glucose levels (BGL) in diabetes. The present study aimed to evaluate the antihyperglycemic potential of charantin-rich extract from the fruits of bitter gourd in in vitro enzyme inhibition assay (alpha-amylase and alpha alpha-glucosidase) and in vivo using carbohydrate-challenged normal and STZ-induced diabetic rats. The bitter gourd fruits were extracted using an ultrasonicator and the extract was assayed for charantin content using HPTLC method. The standardized extract of M. charantia (SMC) contained 0.34 +/- 0.15% w/w charantin. The charantinrich extracts of M. charantia showed concentration-dependent inhibition of alpha alpha- amylase and alpha alpha-glucosidase enzymes with IC50 values 1.41 +/- 0.17 and 2.29 +/- 1.84 mg mL-1, respectively. In starch and sucrose challenged normal rats, pretreatment with SMC (200 mg kg-1-1, b.w.) produced 13.04% and 16.32% reduction in peak BGL as compared to the negative control. In starch and sucrose- challenged diabetic rats (induced by a single intraperitoneal injection of streptozotocin, 50 mg kg-1 b.w.), pre-treatment with SMC @ 200 mg kg-1-1, b.w. caused 7.44 and 8.32% reduction in peak BGL when compared with toxic control. The study provided scientific evidence to the fact that bitter gourd fruit is effective in the manangement of BGL in diabetes that can be mainly attributed to charantin.