Regulatory effect of modified Taohe Chengqi decoction on pancreatic islet alpha cell dysfunction in type 2 diabetic rats

摘要

This study aimed to observe the effect of modified Taohe Chengqi Decoction (MTCD, trade name: Jiangtang Sanhuang Tablet) on incretin and the regulating effect of MTCD on the dysfunction of islet alpha cells. Sixty Sprague Dawley rats were randomly divided into five groups: a control group, diabetes model group, low-dose group (0.781 g of MTCD/kg), high-dose group (1.562 g of MTCD/kg), and dipeptidyl peptidase-4 (DPP-4) inhibitor group (0.47 mg/kg). Type 2 diabetes was simulated through intraperitoneal injection of 35 mg/kg of STZ and feeding with high glucose and lipid. Blood glucose in the high-dose group was lower than in the model group in the eighth week of the experiment. An enzyme-linked immunosorbent assay (ELISA) showed that insulin was significantly reduced after model establishment but increased after treatment with MTCD. The change in glucagon was opposite to that of insulin. After using MTCD, GLP-1 and GIP content increased, but DPP-4 content decreased. The assessment of immunohistochemistry showed that glucagon positive expression in the model group was high, and it declined after treatment with low and high doses of MTCD (P < 0.05). A MagBeads total RNA extraction kit was used to isolate RNA. The qRT-PCR results indicated that the change in the trend of GIPR mRNA expression was similar to that of GLP-1R. The GIPR mRNA increased significantly after using MTCD, and the protein expression of GLP-1R and GIPR showed the same trend in the Western Blot. It is concluded that MTCD could be a potential incretin regulator to reduce the over release of glucagon and produce a multi-target hypoglycemic effect.