Identification of Antidiabetic Compounds from the Aqueous Extract of Sclerocarya birrea Leaves

Vinesh Maharaj; Chidinma Christiana Ezeofor; Dashnie Naidoo Maharaj; Christo J F Muller; Nnini Jennifer Obonye

doi:10.3390/molecules27228095

Identification of Antidiabetic Compounds from the Aqueous Extract of Sclerocarya birrea Leaves

Molecules. 2022 Nov 21;27(22):8095. doi: 10.3390/molecules27228095.

Authors

Vinesh Maharaj¹, Chidinma Christiana Ezeofor^{1

2}, Dashnie Naidoo Maharaj^{1

3}, Christo J F Muller^{4

5

6}, Nnini Jennifer Obonye⁴

Affiliations

¹ Department of Chemistry, Hatfield Campus, University of Pretoria, Hatfield 0028, South Africa.
² Department of Pure and Industrial Chemistry, University of Nigeria, Nsukka, Enugu 410001, Nigeria.
³ Agricultural Research Council-Vegetable, Industrial and Medicinal Plants, Private Bag X293, Pretoria 0001, South Africa.
⁴ Biomedical Research and Innovation Platform (BRIP), South African Medical Research Council (SAMRC), Tygerberg 7505, South Africa.
⁵ Centre for Cardiometabolic Research in Africa, Division of Medical Physiology, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg 7505, South Africa.
⁶ Department of Biochemistry and Microbiology, University of Zululand, KwaDlangezwa 3880, South Africa.

Abstract

Diabetes, a prevalent metabolic condition with a wide range of complications, is fast becoming a global health crisis. Herbal medicine and enhanced extracts are some of the therapeutic options used in the management of diabetes mellitus. The plant-derived molecules and their suitable structure modification have given many leads or drugs to the world such as metformin used as an antidiabetic drug. The stem extract of Sclerocarya birrea has been reported as a potent antidiabetic (glucose uptake) agent. However, the bioactive compounds have not been reported from S. birrea for treatment of diabetes. In this study, the spray-dried aqueous leaf extracts of S. birrea were investigated as an antidiabetic agent using a 2-deoxy-glucose (2DG) technique showing good stimulatory effect on glucose uptake in differentiated C2C12 myocytes with % 2DG uptake ranging from 110-180% that was comparable to the positive control insulin. Three compounds were isolated and identified using bioassay-guided fractionation of the spray-dried aqueous extract of S. birrea leaves: myricetin (1), myricetin-3-O-β-D-glucuronide (2) and quercetin-3-O-β-D-glucuronide (3). Their chemical structures were determined using NMR and mass spectrometric analyses, as well as a comparison of experimentally obtained data to those reported in the literature. The isolated compounds (1-3) were studied for their stimulatory actions on glucose uptake in differentiated C2C12 myocytes. The three compounds (1, 2 and 3) showed stimulatory effects on the uptake of 2DG in C2C12 myocytes with % 2DG uptake ranging from 43.9-109.1% that was better compared to the positive control insulin. Additionally, this is the first report of the flavonoid glycosides (myricetin-3-O-β-D-glucuronide) for antidiabetic activity and they are the main bioactive compound in the extract responsible for the antidiabetic activity. This result suggests that the S. birrea leaves have the potential to be developed for treatment of diabetes.

Keywords: Sclerocarya birrea; antidiabetic; flavonoid glycosides; glucose uptake activity.

MeSH terms

Anacardiaceae* / chemistry
Diabetes Mellitus* / drug therapy
Glucose / metabolism
Hypoglycemic Agents / chemistry
Insulin
Plant Extracts / chemistry

Substances

Hypoglycemic Agents
Plant Extracts
Insulin
Glucose

Grants and funding

Grant number 0000170729, 2017/Department of Science and Technology