Research Of Mechanism Of Action Of TFLC On T2DM Rat Model

Objective: To explore the effects and part mechanism of action of TFLC on experimental T2DM rat model.Method: We established type 2 diabetes mellitus rat model in an improved method. With oral glucose tolerance test (OGTT) and determination of fasting blood glucose and blood insulin levels ,the model was assessed whether established successfully. These rat models were then randomly allocated into model group and treatment group which contained Fenofibrate and Pioglitazone as positive controls. It also contained large dose and small dose of TFLC which were fed 6 weeks for therapy. At the same time, we set up normal control group and high fat control group. At the end of treatment, we did OGTT and insulin tolerance test(ITT). As all rats were sacrificed, blood serum of rats were taken to detect kinds of biochemical indices; liver tissues were kept to carry out dyeing of oil red O to survey the accumulation of fat and messenger RNA was extracted from liver tissues to proceed Realtime-PCR experiments to explore the expression of PTP1B, a related gene of type 2 diabetes mellitus ; pancreatic tissues were obtained to do immunohistochemical analysis;skeletal muscles were used to analyze the expression of PTP1B by Western Blot.Result: The OGTT and insulin sensitivity index(ISI) indicateed that type 2 diabetes mellitus rat model was established successfully in an improved method. Body weights and glucose in urine of T2DM model group are higher than normal control group. After medicating, several serum index of rats in treatment group were significantly decreased, such as fasting blood glucose(FBG), glycosylated hemoglobin(HbA1c),fasting insulin(Fins),ISI, triglyceride(TG), total cholesterol(TC) and so on. It was suggested the enhancement of insulin sensitivity. Staining on liver tissue slices with oil red O showed a significant reduction of lipid droplet in treatment groups, compared with T2DM group and high fat control group. Results of RT Realtime-PCR displayed that mRNA of PTP1B in model group increased significantly and mRNA of PTP1B in treatment groups were decreased significantly compared to T2DM group. Pancreatic islet area in model group was much smaller than in normal control. Consistent with this, gene Bak1 was expressed higher in model group. However, pancreatic islet area could be partially restored and expression of Bak1 could be inhibited by TFLC. Detection of Western Blot of skeletal muscles indicates a notable reduction of PTP1B expressions in large dose of TFLC treatment group compared to T2DM group.Conclusion:TFLC could reduce blood fat and glucose apparently. Its role may be related to the proliferation of pancreatic islets, the reduction of apoptosis in pancreas, decrease of PTP1B in mRNA and protein levels, and then enhancement of insulin sensitivity.