杞丹方对糖尿病小鼠降血糖作用及机制研究

  目的  研究杞丹方对糖尿病小鼠降血糖作用并探讨相关机制。  方法  取SPF级ICR雄性小鼠, 禁食16 h后腹腔注射四氧嘧啶120 mg·kg-1, 5 d后禁食12 h测血糖, 血糖值在10~25 mmol·L-1为糖尿病造模成功。将造模成功的ICR雄性糖尿病小鼠, 分为模型组, 二甲双胍组, 杞丹方低、中、高剂量组(0.34、0.67、1.34 g·kg-1·d-1), 正常ICR雄性小鼠为空白组, 给药30 d。每10 d记录体质量和空腹血糖(FBG)1次, 30 d后进行葡萄糖耐量试验(OGTT); ELISA法检测血清胰岛素水平并摘取胰腺、肝脏组织, 进行HE染色, 观察其病理改变; 采用Western blot和qPCR检测肝脏组织IRS-1、PI3K、AKT和GLUT4的表达水平。  结果  与模型组相比, 杞丹方中、高剂量组小鼠FBG水平、糖耐量显著降低(P < 0.01)，血清胰岛素水平显著升高(P < 0.01)。杞丹方各剂量组胰腺和肝脏组织结构有明显改善, 胰岛形态得到一定程度恢复, 少见肝脏组织异常与血管充血。杞丹方高剂量组能显著上调肝脏组织中的p-IRS-1/IRS-1、p-PI3K/PI3K、p-AKT/AKT和GLUT4蛋白表达水平(P < 0.01);显著上调肝脏组织中的IRS-1、PI3Kp85α、AKT1和GLUT4 mRNA水平(P < 0.01)。  结论  杞丹方对糖尿病小鼠具有降血糖作用, 其作用机制是通过调控IRS-1/PI3K/AKT信号通路来实现的。 

Study on the Hypoglycemic Effect and Mechanism of Qidan Fang on Diabetic Mice

  OBJECTIVE  To investigate the hypoglycemic effect of Qidan Fang on diabetic mice and explore its relevant mechanism.  METHODS  The SPF ICR mice were intraperitoneally injected with 120 mg·kg-1 alloxan after fasting for 16 h. The blood glucose was measured after fasting for 12 h after 5 d. The blood glucose of 10~25 mmol·L-1 was defined as the successful establishment of the diabetic mouse model. The male diabetic ICR mice were divided into the model group, metformin group, low-, medium- and high-dose Qidan Fang groups (0.34, 0.67, 1.34 g·kg-1·d-1, respectively), and administrated for 30 d. Additionally, normal male ICR mice were selected as the blank group. Body mass and fasting blood glucose (FBG) were recorded once every 10 d, and a glucose tolerance test (OGTT) was performed after 30 d. Serum insulin level was detected by ELISA, and then pancreas and liver tissues were collected for HE staining to observe their pathological changes. The expression levels of IRS-1, PI3K, AKT and GLUT4 in the liver tissues were determined by Western blot and qPCR.  RESULTS  Compared with the model group, the level of FBG and glucose tolerance decreased significantly (P < 0.01), and the serum insulin level increased significantly (P < 0.01), in the medium- and high-dose Qidan Fang groups; The tissue structure of the pancreas and liver was significantly improved, islet morphology recovered to a certain extent, and liver tissue abnormalities and vascular congestion were rarer in the low-, medium- and high-dose Qidan Fang groups. High dose of Qidan Fang could significantly up-regulate the protein expression levels of p-IRS-1/IRS-1, p-PI3K/PI3K, p-AKT/AKT and GLUT4 in liver tissues (P < 0.01), while significantly up-regulate the mRNA levels of IRS-1, PI3Kp85α, AKT1 and GLUT4 in liver tissues (P < 0.01).  CONCLUSION  Qidan Fang has a hypoglycemic effect on diabetic mice, and its mechanism is relative to the regulation of IRS-1/PI3K/AKT signaling pathway.