Astragalus polysaccharide alleviates type 2 diabetic rats by reversing the glucose transporters and sweet taste receptors/GLP-1/GLP-1 receptor signaling pathways in the intestine-pancreatic axis

The present study revealed that Astragalus polysaccharide (APS) alleviated the symptoms of type 2 diabetes mellitus (T2DM) rats, improved the histopathology of pancreas and promoted insulin secretion. Gene expression analysis found that APS significantly increased the expressions of Glucagon-like peptide 1 and sweet taste receptors (STRs) signaling molecules, and decreased the expressions of glucose transporters of SGLT-1 and GLUT2 in the intestine of T2DM rats. Furthermore, APS significantly increased the expressions of GLP-1 and STRs signaling molecules in the pancreas of T2DM rats, as well as the expression of GLP-1 receptor signaling molecules. Conversely, APS remarkably decreased the expressions of GLUT2 and KCNJ11 in the pancreas of T2DM rats. These results suggested that the physiological roles of STRs in the intestine and pancreas were involved in glucose uptake and insulin secretion, respectively. APS alleviated T2DM rats by reversing expressions of glucose transporters and STRs/GLP-1/GLP-1R pathways in the intestine-pancreatic axis of T2DM rats.