Protein glycation and aggregation inhibitory potency of biomolecules from black gram milled by-product

BACKGROUND: Persistent hyperglycaemia causes increased advanced glycation end products (AGEs), which contribute to the pathogenesis of diabetic complication. Therefore, effect of black gram milled by-product (BGBP) extract on inhibition of AGE formation in a bovine serum albumin (BSA)/glucose system was investigated. RESULTS: BGBP extract had a total polyphenol content of 82 mg GAE g(-1) and flavonoid content of 46 mg CE g(-1). Ferulic acid, protocatechuic acid, gallic acid, gentisic acid, isovitexin, vitexin and epicatechin were the major bioactives in the extract. BGBP extract exhibited an effective Fe2+ chelating activity. Size exclusion-high-performance liquid chromatographic studies indicated that upon BSA-AGE formation the BSA monomer content was 38%; however, in the presence of BGBP extract at 50 and 100 mu g levels, the monomer content increased and it was found to be 48% and 73%, respectively. BGBP extract at 50 and 100 mu g levels decreased the protein carbonyl and fructosamine contents, and quenched the fluorescence intensity of glycated BSA in a dose-dependent manner. Further, fluorescence and transmission electron microscopic studies confirmed the decrease in formation of AGEs by BGBP extract. CONCLUSION: As BGBP extract inhibited the formation of AGEs, the extract can be used as a nutraceutical or it can be incorporated into food products to obtain functional foods. (C) 2016 Society of Chemical Industry