Standardized Emblica officinalis fruit extract inhibited the activities of α-amylase, α-glucosidase, and dipeptidyl peptidase-4 and displayed antioxidant potential

Abstract

BACKGROUND: Emblica officinalis, known as amla in Ayurveda, has been used as a folk medicine to treat numerous pathological conditions, including diabetes. However, the novel extract of E. officinalis fruit extract (amla fruit extract, AFE, Saberry®) containing 100 g kg−1 β-glucogallin along with hydrolyzable tannins has not yet been extensively studied for its antidiabetic potential. OBJECTIVE: The aim of this study was to investigate the antidiabetic and antioxidant activities of AFE and its stability during gastric stress as well as its thermostability. METHODS: The effect of AFE on the inhibition of pancreatic α-amylase and salivary α-amylase enzymes was studied using starch and yeast α-glucosidase enzyme using 4-nitrophenyl α-d-glucopyranoside as substrate. Further, 2,2-diphenyl-1-picrylhydrazyl radical scavenging and reactive oxygen species inhibition assay was performed against AFE. RESULTS: AFE potently inhibited the activities of α-amylase and α-glucosidase in a concentration-dependent manner with half maximal inhibitory concentration (IC50) values of 135.70 μg mL−1 and 106.70 μg mL−1 respectively. Furthermore, it also showed inhibition of α-glucosidase (IC50 562.9 μg mL−1) and dipeptidyl peptidase-4 (DPP-4; IC50 3770 μg mL−1) enzyme activities. AFE is a potent antioxidant showing a free radical scavenging activity (IC50 2.37 μg mL−1) and protecting against cellular reactive oxygen species (IC50 1.77 μg mL−1), and the effects elicited could be attributed to its phytoconstituents. CONCLUSION: AFE showed significant gastric acid resistance and was also found to be thermostable against wet heat. Excellent α-amylase, α-glucosidase, and DPP-4 inhibitory activities of AFE, as well as antioxidant activities, strongly recommend its use for the management of type 2 diabetes mellitus. © 2019 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.