Anti‐glycation Effect and Advanced Glycation End‐products Cross‐link Breaking Ability of Sclerocarya birrea Stembark Extracts

Abstract

Advanced glycation end‐products (AGEs) are implicated in the pathogenesis of late microvascular complications of diabetes mellitus. Currently, there is no clinically approved anti‐glycation agent with minimal side effects. The objective of the study was to investigate the anti‐glycation effect and AGE‐cross‐link breaking ability of Sclerocarya birrea (S. birrea) stembark extracts. Bovine serum albumin (BSA) was incubated with fructose in the presence of different stembark extracts of S. birrea at 37°C for 40 days. Fluorescent AGEs (FAGEs), total immunogenic AGEs (TIAGEs) and carboxymethyl lysine (CML) formed were measured using spectrofluorometry and enzyme‐linked immunosorbent assay (ELISA). The ability of S. birrea stembark extracts to break BSA‐AGE‐collagen cross‐links was also investigated by means of ELISA.Ethyl acetate, methanol and water extracts significantly inhibited the formation of FAGEs than the standard inhibitor aminoguanidine. Hexane extract demonstrated significantly higher anti‐glycation activity than aminoguanidine against TIAGEs. The water extract exhibited higher inhibitory activity than aminoguanidine against the formation of CML. With regard to the ability to break down AGE‐cross‐links, S. birrea stembark methanol and water extracts demonstrated higher ability to break AGE‐cross‐links than the hexane and ethyl acetate extracts. In conclusion, crude S. birrea stembark extracts have the ability to inhibit the formation of AGEs and to breakdown AGEs‐protein cross‐links. The results of this study may lead to the isolation of bioactive phytochemicals from S. birrea stembark extracts that may be used for the prevention of vascular complications of diabetes.Support or Funding Information1. National Research Foundation (NRF), South Africa. 2. Sefako Makgatho Health Sciences University (SMU), South Africa