Pumpkin Polysaccharide Extracted by Subcritical Water: Physicochemical Characterization and Anti-Diabetic Effects in T2DM Rats.

SCOPE This study aimed to optimize the extraction of pumpkin polysaccharide by subcritical water, investigate the physicochemical properties and biological activities of pumpkin polysaccharide. METHODS AND RESULTS Subcritical water was used to extract pumpkin polysaccharide. The structure and composition of pumpkin polysaccharide were analyzed by infrared spectroscopy, gel filtration chromatography, and high-performance liquid chromatography. The hypoglycemic and hypolipidemic potential of pumpkin polysaccharide were determined by the physicochemical indexes, pathological and immunohistochemical analysis in T2DM rats induced by STZ + high-fat diet. The optimal conditions for subcritical water were 1:15, 150°C, and 10 min. Pumpkin polysaccharide had α-configurations and were mainly composed of seven different monosaccharides, and it exhibited good free-radical scavenging ability and inhibition of α-amylase, α-glucosidase, and pancreatic lipase activities. Pumpkin polysaccharide treatment in T2DM rats significantly decreased the concentrations of blood glucose, insulin, TC, TG, LDL-C and MDA; increased the levels of HDL-C; and enhanced the antioxidant enzymes activities (SOD and CAT). Histopathology and immunohistochemical analyses revealed that pumpkin polysaccharide had protective effects on kidney and pancreatic organs in T2DM rats. CONCLUSION Pumpkin polysaccharide extracted by SWE shows great potential as functional food ingredients and candidates for T2DM treatment. This article is protected by copyright. All rights reserved.