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

J Sci Food Agric. 2020 Jan 30;100(2):509-516. doi: 10.1002/jsfa.10020. Epub 2019 Nov 13.

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.

Keywords: DPP-4; Saberry®; amla fruit extract; type 2 diabetes mellitus; α-amylase; α-glucosidase; β-glucogallin.

MeSH terms

  • Antioxidants / chemistry*
  • Antioxidants / isolation & purification
  • Diabetes Mellitus, Type 2 / enzymology
  • Dipeptidyl Peptidase 4 / chemistry
  • Dipeptidyl-Peptidase IV Inhibitors / chemistry*
  • Dipeptidyl-Peptidase IV Inhibitors / isolation & purification
  • Fruit / chemistry*
  • Glycoside Hydrolase Inhibitors / chemistry*
  • Glycoside Hydrolase Inhibitors / isolation & purification
  • Humans
  • Hypoglycemic Agents / chemistry
  • Hypoglycemic Agents / isolation & purification
  • Phyllanthus emblica / chemistry*
  • Plant Extracts / chemistry*
  • Plant Extracts / isolation & purification
  • alpha-Amylases / antagonists & inhibitors
  • alpha-Amylases / chemistry
  • alpha-Glucosidases / chemistry

Substances

  • Antioxidants
  • Dipeptidyl-Peptidase IV Inhibitors
  • Glycoside Hydrolase Inhibitors
  • Hypoglycemic Agents
  • Plant Extracts
  • alpha-Amylases
  • alpha-Glucosidases
  • Dipeptidyl Peptidase 4

Grant support