Effects of sweet corncob polysaccharide on pancreatic protein expression in type 2 diabetic rats

Abstract

The cobs of sweet corn, also known as vegetable corn, are a nutritionally rich agricultural by-product. Sweet corncob polysaccharide (SCP-80-I) is a bioactive macromolecule extracted from the sweet corncob. Previous studies have shown that SCP-80-I has beneficial biological activities, including anti-oxidative and hypoglycemic properties. Previously, we showed that SCP-80-I had hypoglycemic effects, but the overall molecular changes associated with SCP-80-I have not yet been clarified in vivo. In this study, we investigated the hypoglycemic effects of SCP-80-I in diabetic rats with insulin resistance and analyzed the hypoglycemic mechanisms of SCP-80-I using tandem mass tag (TMT) -labeled quantitative proteomics. Using gene onotology (GO) annotations and kyoto encyclopedia of genes and genomes (KEGG) pathway analysis, the biological process, cell composition, and molecular function terms associated with the differentially expressed proteins were identified, as were the associated signaling pathways. In total, 4780 proteins exhibited a fold-change greater than 1.5. Six differentially expressed proteins related to the development and treatment of diabetes were selected, encoded by the genes Pik3r5, Ndufb3, Pygl, Cbl, Prkcd, and Stat1. SCP-80-I induced hypoglycemia mainly through the PI3K-Akt and JAK-STAT signaling pathways. SCP-80-I also ameliorated diabetes by regulating the expression of the Pik3r5, Ndufb3, Pygl, Cbl, Prkcd, and Stat1 genes. This study provided a theoretical basis for the treatment of diabetes and the development of hypoglycemic drugs. Our results suggested that SCP-80-I plays a beneficial role in reducing blood glucose in diabetic mice, which helps to clarify the molecular mechanisms by which sweet corncob polysaccharide reduces blood glucose.

Keywords

• Sweet corncob polysaccharide
• Type 2 diabetes mellitus
• Proteomics