The Effect of the Extracts of Endophytic Fungi on Pancreatic α-Amylase Activity
Abstract
Inhibitors of pancreatic -amylase offer an effective strategy to lower the levels of postprandial hyperglycemia by control of starch breakdown. Among 86 fungal endophytes isolated from 15 medicinal plants Aspergillus terreus-AF104S, Aspergillus egypticus-HT166S and Penicillium sp.-CC200 exhibited strong pancreatic amylase inhibitory potential were selected. Endophytes were subjected to ethyl acetate extraction and tested for -amylase inhibition, in order to assess and evaluate their inhibitory potential on pancreatic -amylase. Analysis showed concentration dependent enzyme inhibition up to 83% with half inhibition (IC50) values for less 25 mgmL -1 , which is lower than acarbose as control. It was observed 3-fold increasing of V max and maintenance K m at control level in the presence of extracts A. terreus-AF104S and Penicillium sp.-CC200, while in presence of extract A. egypticus-HT166S K m was doubled, and V max was maintained at the control level. Kinetic studies allow proposing the competitive mode of -amylase inhibition by extracts A. egypticus-HT166S and uncompetitive inhibition by extracts A. terreus-AF104S and Penicillium sp.-CC200.