Degradation of sweet corn cob polysaccharides by ultrasound-assisted H2O2/Vc treatment: Structural characterization and hypoglycemic effects in vitro and in vivo.

To investigate the inhibitory potential of plant-degraded polysaccharides on glycosidases and elucidate the mechanism by which they alleviate type 2 diabetes mellitus (T2DM), a degraded sweet corn cob polysaccharide (UHDSCP) was prepared using ultrasound-assisted hydrogen peroxide-ascorbic acid oxidation (H2O2/Vc). UHDSCP was subsequently characterized using various analytical techniques, including UV spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, gel permeation chromatography (GPC), high-performance liquid chromatography (HPLC), scanning electron microscopy (SEM), and atomic force microscopy (AFM). Our findings indicated that UHDSCP has a molecular weight of 14.82 kDa and is composed primarily of mannose, glucose, galactose, and fucose at a molar ratio of 1.705:93.301:1.077:2.501. Additionally, UHDSCP exhibited α- and β-glycosidic bonds. Our findings revealed that UHDSCP can inhibit the activity of α-amylase and α-glucosidase and reduce oxidative stress in vitro. UHDSCP also exerted a hypoglycemic effect in T2DM mice, as determined by a decrease in the activities of disaccharidases in the small intestine, including maltase, sucrase, and lactase. Additionally, UHDSCP could modulate lipid metabolism in T2DM mice and alleviate oxidative stress in hepatic and pancreatic tissues. Moreover, UHDSCP ameliorated T2DM-induced inflammatory responses in the intestine and liver by restoring the integrity of the intestinal barrier. Considering these results, this study can serve as a reference for the inclusion of UHDSCP in the diet to exert hypoglycemic effects and alleviate T2DM through multiple pathways.