Experimental Study On The Effect Of Tangtongyin Formula On Glycolipid Metabolism And The Protective Effect Of Pancreatic Tissue In Type 2 Diabetic Rats

Objective:To observe the effect of Tangtongyin Formula on glucolipid metabolism in type 2 diabetic rats and its regulation on JNK signaling pathway and PI3K-AKT signaling pathway in pancreatic tissue,and to explore the protective effect and mechanism of Tangtongyin Formula on pancreatic tissue in type2 diabetic rats.Methods:Fifty SPF SD male rats were randomly divided into normal groups of ten,and the remaining 40 rats were treated with high-fat diet and low-dose multiple intraperitoneal injection of streptozotocin to prepare the model of type 2diabetic rats.The Forty rats successfully modeled were divided into the model group,Tangtongyin low(10g·kg^-1),medium(20g·kg^-1)and high dose(30g·kg^-1)groups,ten rats in each group,the treatment groups were given Tangtongyin Formula by gavage for intervention,the normal group and the model group were given equal volume of double steaming water by gavage,once a day,for 8 weeks,fasting 12 hours before subsections,and blood samples were collected from the tail vein.Fasting blood glucose of the rats was detected by glucose oxidase method.Blood was collected from the abdominal aorta and serum was separated.Serum insulin level was detected by Elisa.Insulin resistance index was calculated according to the formula:HOMA-IR=FBG×FINS/22.5.Serum triglyceride and total cholesterol were detected by automatic biochemical analyzer.Serum free fatty acids were detected according to copper reagent colorimetry.Serum superoxide dismutase was detected by xanthine oxidase method.The content of malondialdehyde in serum was detected by thiobarbital method.real-time fluorescent quantitative PCR method to detect pancreatic tissue of rats in the JNK1,PDX-1,AKT and IRS-1 m RNA level,using the immunohistochemical detection of pancreatic tissue of rats JNK1,PDX-1,AKT and IRS-1 protein expression.Results:Compared with the normal group SOD of the model group were significantly decreased（P<0.01）,FBG,HOMA-IR,TC,TG,FFA and MDA were significantly increased（P<0.01）,FINS had no significant difference（P>0.05）,m RNA and protein expression of PDX-1,AKT and IRS-1 were significantly decreased（P<0.01）,and m RNA and protein expression of JNK1 were significantly increased（P<0.05,P<0.01）.Compared with the model group,SOD of in each dose group of Tangtongyin were significantly increased（P<0.01）,FBG,HOMA-IR,TC,TG,FFA and MDA were significantly decreased（P<0.01）,FINS had no significant difference between the treatment groups（P>0.05）.The m RNA and protein expressions of PDX-1 in the pancreas of rats in all dose groups were significantly increased（P<0.05,P<0.01）,and the m RNA and protein expressions of JNK1 were significantly decreased（P<0.05,P<0.01）.The expression of AKT in high dose group was significantly increased（P<0.05,P<0.01）,and the expression of IRS-1in medium and high dose group was significantly increased（P<0.05,P<0.01）,and the expression of IRS-1 protein in each dose group was significantly increased（P<0.01）.Conclusion:（1）Tangtongyin Formula can reduce FBG,TG,TC and FFA in type 2diabetes rats,thus improving the disorder of glucose and lipid metabolism.Increase SOD,reduce MDA and HOMA-IR,down-regulate the m RNA and protein expression of JNK1 in pancreatic tissue,up-regulate the m RNA and protein expression of PDX-1,AKT and IRS-1 in pancreatic tissue,so as to fight oxidative stress,improve insulin resistance and reduce islet cell damage.（2）The protective effect of Tangtongyin Formula on pancreatic tissue may be related to the inhibition of JNK signaling pathway and the activation of PI3K-AKT signaling pathway.（3）The effect of Tangtongyin Formula on type 2 diabetes was the best in the high-dose group,which provided the experimental basis for the optimization of clinical dose selection.