Inhibitory effects of n-hexane fraction from hydro-methanolic (2:3) extract on alpha-amylase and alpha-glucosidase activities of sepal of Salmalia malabarica: An approach through in vitro study

The antidiabetic therapeutic approach is to reduce gastrointestinal glucose production and absorption through the inhibition in carbohydrate-digesting enzymes such as a-amylase and a-glucosidase. The present study was designed to investigate the a-amylase and a-glucosidase inhibition in the n-hexane fraction of sepal of Salmalia malabarica. The fraction showed concentration-dependent a-amylase (IC50 = 50.17 mg/L) and a-glucosidase (IC50 = 61.04 mg/L) inhibitory activity. The positive in vitro enzyme inhibition tests results were confirmed with an oral starch tolerance test with 18 hour fasted normoglycemic rats. Phytochemical study of the said plant part fraction revealed that is rich in total phenolic contents, flavonoids, and flavonol, which may be responsible for its pharmacological activity. In an acute toxicity study, the n-hexane fraction up to the dose level of 3000 mg/kg body weight did not exhibit any lethality or toxic symptoms. From these results, it may be concluded that the n-hexane fraction may have an inhibitory effect on intestinal a-amylase and a-glucosidase activity, and can be used effectively as a safer alternative therapy to control postprandial hyperglycemia. Copyright (C) 2013, Taiwan Genomic Medicine and Biomarker Society. Published by Elsevier Taiwan LLC. All rights reserved.