Title:Euclea natalensis Suppresses Postprandial Hyperglycemia in Rats via the
Inhibition of α-Glucosidase: In vitro, in vivo, and Molecular Docking Studies
Volume: 10
Author(s): Keagile Bati*, Runner R.T Majinda, Goabaone Gaobotse and Tebogo E. Kwape
Affiliation:
- Department of Biology and Biotechnology, Faculty of Science, Botswana International University of Science and
Technology (BIUST), Private Bag 16, Palapye, Botswana
Keywords:
Euclea natalensis, diabetes mellitus, postprandial hyperglycemia, alpha-glucosidase, FTIR fingerprinting
Abstract: Background: Postprandial hyperglycemia is a key factor in type 2 diabetes, and its
management is critical in alleviating the deleterious consequences of diabetes and its associated
micro and macrovascular complications.
Objective: The current study aims to determine the effect of Euclea natalensis leaf extracts on α-
glucosidase inhibition in vitro and postprandial hyperglycemia in vivo in rats.
Methods: Sequentially extracted leaf extracts of Euclea natalensis were evaluated for their inhibitory
effects on α-glucosidase in vitro and the suppression of postprandial hyperglycemia in
normoglycemic rats. The extracts were fingerprinted using a Fourier-transform infrared spectrophotometer
(FTIR), and the bioactive compounds were evaluated by molecular docking for their
interaction with α-glucosidase.
Results: FTIR fingerprinting of the extracts showed that they contain functional groups of important
bioactive phytochemicals. The extracts inhibited α-glucosidase in vitro, with the methanol
extract (1 mg/mL) showing the highest inhibitory effect of 93.52 ± 1.50% compared to
69.62% ± 1.45 of the standard drug acarbose (0.05 mg/mL). The extracts also reduced postprandial
hyperglycemia in rats in a sucrose tolerance test, where the hexane and methanol extracts
performed similarly to Acarbose. Molecular docking studies showed that 20(29)-lupene-3β-
isoferulate 3 is the most potent α-glucosidase inhibitor with the lowest binding energy of -10.79
kcal/mol, 2 hydrogen bonds with residues ASP1526 and ASP1157, and numerous Van der Waal
interactions with amino acids in the binding pocket of α-glucosidase.
Conclusion: Euclea natalensis leaf extracts were found to suppress postprandial hyperglycemia
by inhibiting α-glucosidase activity; thus, it has a promising potential for use as an antidiabetic
agent.
