The Mechanism Behind the Anti-Apoptotic Effects of TNK on Islet β Cell in Type 2 Diabetic ZDF Rats / 世界科学技术-中医药现代化

ABSTRACT

This study aimed to investigate the anti-apoptotic effects of Tangnaikang (TNK) on islet β cells in Zucker diabetic fatty (ZDF) rats.Six male fa/+ ZDF rats were took as the control group,while other thirty male fa/fa ZDF rats were divided into five groups at random:the model group,the metformin group,the high-,mediumand low-dose TNK groups,depending on their body weight and random blood glucose.Prior to the administration,fasting blood glucose and fasting insulin were measured by drawing blood with inner canthusl.Materials were prepared when administered for six weeks.Fasting blood glucose and fasting insulin were detected again.When the sections of the rat pancreatic tissue were embedded,the morphological changes of the islet were observed via HE staining,and the apoptosis of islet β cell were observed using TUNEL.Positive expression of Caspase-3,the transduction enzyme of cell death signal,was tested by immunohistochemical method.It was found that the fasting blood glucose of the (fa/fa) ZDF rats in the high-,medium-and low-dose TNK group was significantly improved after administration (P ＜ 0.01).The serum insulin of rats in the high-,medium-and low-dose TNK group arised compared with the model group,while the high-and low-dose TNK group showed differences in a statistical sense.Compared with the model group,the HOMA-IR of all the treatment group decreased,while significant difference was presented between the high-dose TNK group and the metformin group.HE staining showed that the morphology of the islet β cell of the rats in all the treatment group was improved.The results of TUNEL showed significantly apoptotic changes on islet β cell of the fa/fa ZDF rats.Compared with the model group,the positive expression of TUNEL in the metformin group and the high-dose TNK group were significantly reduced (P ＜ 0.05).The result of immunohistochemistry method showed that the protein levels of Caspase-3 in the metformin group and the high-dose TNK group decreased (P ＜ 0.05).In conclusion,it was demonstrated that TNK effectively reduced the apoptosis of islet β cells in fa/fa ZDF rats,which presented a protective effect.