Anti-diabetic potential of anthocyanin-rich fractions from purple-wheat (Triticum aestivum L.) cultivars and their correlation with metabolite profiles

Abstract Wheat ( Triticum aestivum L.) is a primary source of nutrition worldwide, and the development of wheat varieties with enhanced functionality has gained considerable interest. This study investigated the antidiabetic activities of three purple wheat varieties and their correlations with their metabolite profiles. We evaluated the antioxidant and antidiabetic activities of the anthocyanin-rich fractions derived from these cultivars. Anthocyanins were extracted from wheat bran using acidified 80% methanol and purified using ion-exchange chromatography. The metabolites were analyzed using UHPLC-HESI-Orbitrap MS/MS. Antioxidant capacity was evaluated by measuring the total polyphenol content and analyzing DPPH, ABTS, ORAC, and ROS levels. Antidiabetic activity was determined through α-glucosidase inhibition and glucose uptake in insulin-resistant HepG2 cells. The effect on the PI3K/AKT signaling pathway was investigated using western blot analysis. The “Ari-heukchal” cultivar exhibited the highest total polyphenol content, antioxidant capacity, and α-glucosidase inhibitory activity. Treatment of insulin-resistant HepG2 cells with 200 µg/mL of the anthocyanin-rich fraction improved glucose uptake and significantly increased AKT phosphorylation at Ser473. This effect was attributed to the high anthocyanin content in the “Ari-heukchal” cultivar. The findings support the potential use of natural anthocyanin pigments from purple-wheat cultivars for the development of functional materials from colored grains.