胰岛素抵抗（IR）是胰岛素在周围组织摄取及清除葡萄糖作用减低。胰岛素信号通路的障碍是发生IR的重要机制。我们在前期研究中发现鬼针草黄酮(BBLF)具有降血糖及减少血清胰岛素作用，从而改善IR。其参与糖代谢和胰岛素信号转导的分子机制尚不明确。目前研究发现，胰岛素信号转导主要通过MAPK、PI3K、β-arrestin2三条通路进行，为明确BBLF在胰岛素信号通路中的作用，本课题拟采用软脂酸（PA）诱导HepG2细胞胰岛素抵抗，运用葡萄糖消耗试验、葡萄糖摄取试验、RT-PCR、Western Blot试验等实验方法，探讨BBLF对胰岛素抵抗HepG2细胞中的PI3K、Akt、GLUT4 、JNK、P38MAPK、β-arrestin2、Scr等相关蛋白及基因表达的影响，明确BBLF参与胰岛素信号转导的信号通路，从而为开发研究BBLF治疗胰岛素抵抗提供新的靶点。

Insulin Resistance（IR）is a pathological basis in 2 type diabetes, which cause by the effection of insulin decreased on uptakeing and clearing glucose in peri-constitution. The dysfunction of signal pathway is the important cause of IR,therefore,to enhance the activity of insulin signal pathway is a key strategy to prevent and treat insulin resistance.Our prophase research showed that Bidens Bipinnata L.flavonoids (BBLF) had the effects on improving hypoglycemic and decreasing serum insulin in diabetic mice , so as to improve the sensitivity of insulin of body. But the mechanisms of hypoglycemic and decreasing insulin resistance of BBLF are not clear,especially the mechanisms of signal transduction of insulin. In present studies it was found that there are three signal pathways in insulin transduction,which are Mitogen-activated protein kinase pathway(MAPK pathway), Phosphatidylinositide-3 kinase pathway(PI3K pathway) andβ-arrestin2 pathway.In order to investigate the intervention effects of BBLF on signal pathways of insulin,the HepG2 cells are induced by palmitic acid(PA).Through the glucose consumption and glucose uptake testing in HepG2 cells respectively,the concentration and inducing time of PA are ascertained.The concentration of BBLF is selected by MTT testing.And then HepG2 cells are treated by different groups.At last,RT-PCR and Western Blot testing are adoped to measure relative mRNA expression and protein expression of PI3K,Akt, GLUT4, JNK, P38MAPK,β-arrestin2,Scr,and so on.These proteins exist in signal pathway of insulin respectively. Then BBLF's the molecular mechanism on improving the insulin resistance in HepG2 cell induced by PA is identified.It's a good idea to investigate molecular target of BBLF treatment in insulin resistance.