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 µg levels, the monomer content increased and it was found to be 48% and 73%, respectively. BGBP extract at 50 and 100 µg 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. © 2016 Society of Chemical Industry