大豆苷改善3T3-L1脂肪细胞胰岛素抵抗及其作用机制-药理学专业论文.docx

ABSTRACT Objective: To investigate the effects of Daidzin on the proliferation and differentiation of 3T3-L1 preadipocytes, and glucose and lipid metabolism of insulin resistant (IR) adipocytes and its potential mechanism. Methods: The 3T3-L1 preadipocytes were differentiated into adipocytes with DMEM containing dexamethasonin, insulin and isobutyl-methylxanthine, and then divided into control group, medium group, drug groups and positive group. The proliferation of 3T3-L1 preadipocytes was tested by MTT assay and its differentiation was determined by oil red O staining when cells were treated with Daidzin (0.1, 0.3, 1, 3, 10 μM) for 48h. The IR model was induced by 1μM dexamethasonin. Cellular glucose consumption was determined by GOD-POD assay, the content of fatty acid (FFA) by colorimetric method and the adiponectin secretion by ELISA. The expression of PPARγ, adiponectin, IRS-1, GLUT4 and PTP1B mRNA in IR adipocytes were analyzed by qPCR. The PPARγ-transactivation activity was examined by using a GAL4 chimeric receptor assay and the activity of PTP1B by colorimetric method. Results: Compared with medium group, Daidzin increased the proliferation of 3T3-L1 preadipocytes at 3, 10μM significantly (P0.05 or P0.01), while inhibited its differentiation significantly when cells were treated with 0.1 ~ 1μM (P0.05 or P0.01). Compared with medium group, the glucose consumption of model group was significantly reduced by 42.5 % when cells were treated with 1μM dexamethasonin for 96h (P0.01). The IR model was established successfully. Compared with the model group, Daidzin enhanced glucose consumption both in basic and insulin stimulation states in a dose-dependent manner when cells were treated at 0.3~10μM (P0.05 or P0.01) and decreased FFA production at 0.1 ~ 10 μM (P0.05 or P0.01). Compared with medium group, Daidzin significantly inhibited PTP1B activity (P0.05or P0.01), in which could be up to 37.67% in the presence of 1μM (P0.01).Also, it showed