Bioactive feruloylated xylooligosaccharides derived from Pearl millet (Pennisetum glaucum) bran with antiglycation and antioxidant properties

Non-communicable diseases have a promising link with the glycated proteins and advanced glycation end products, which are formed during hyperglycemic conditions of diabetes mellitus. Consumption of whole grain millets serves as an aid in the management of lifestyle disorders. Despite being the most robust and widely cultivated millet grain and its position as a major food staple, there has been a lack of research on the effects of pearl millet on human health and disease prevention. Therefore, this study was aimed at utilizing pearl millet bran, an agro-industrial waste, to derive feruloylated xylooligosaccharides (FXOS) by enzymatic hydrolysis and examine their potential as a natural antioxidant and antiglycating agent. The isolated FXOS were composed of 25.19 mg/g bound ferulic acid, 227.5 mg/g arabinose, and 359.9 mg/g xylose as the major monosaccharides besides 25.8 mg/g glucose, 27.2 mg/g galactose, and 14 mg/g glucuronic acid with the total arabinoxylan content of 51.5%. FTIR analysis confirmed the presence of backbone having beta-glycosidic linkages and bound phenolic group. Further, antiglycation potential was studied with the help of inhibition of fructosamine and protein carbonyl formation and fluorescence measurements. FXOS showed a potent antiglycation effect in the bovine serum albumin (BSA)/glucose model with an inhibition rate of 54.6, 62.8, and 87.7% at 1 mg/mL during the early, middle, and late stages of glycation, respectively. FXOS also inhibited protein aggregation, as confirmed by Thioflavin-T fluorescence measurements and SDS-PAGE. In addition, we evaluated the antioxidant property of FXOS by DPPH, ABTS, FRAP, superoxide radical scavenging, and ferrous ion chelating assays. Our findings suggest that FXOS from pearl millet bran can be utilized as a constituent of functional foods with antiglycation and antioxidant properties.