葫芦巴改善瘦素缺陷型ob/ob小鼠炎症及胰岛素抵抗的机制研究

Study on the Mechanism of Fenugreek Improving Inflammation and Insulin Resistance in Leptin-Deficient ob/ob Mice

目的探讨葫芦巴改善瘦素缺陷型ob/ob小鼠炎症及胰岛素抵抗的机制。方法小鼠分为正常饮食组(NC组)、高脂饮食组(HFD组)、葫芦巴低剂量治疗组(Fenu/L组)、葫芦巴高剂量治疗组(Fenu/H组)。葫芦巴干预12周后,测量各组小鼠体重;全自动生化仪检测小鼠血脂水平;手持血糖仪检测小鼠空腹血糖水平;酶联免疫吸附试验(enzyme linked immunosorbent assay,ELISA)检测小鼠空腹血清胰岛素、血清白细胞介素(interleukin,IL)-1β、IL-6及单核细胞趋化蛋白(monocyte chemoattractant protein,MCP)-1水平,计算胰岛素抵抗指数(homeostasis model assessment-insulin resistance,HOMA-IR);实时荧光定量聚合酶链式反应(real time-quantitative polymerase chain reaction,RT-qPCR)检测皮下脂肪组织中IL-1β、IL-6、MCP-1的mRNA表达水平;蛋白质印迹法(western blot,WB)检测皮下脂肪组织胰岛素受体和c-Jun氨基末端激酶(c-Jun N-terminal kinase,JNK)炎症信号通路的相关蛋白磷酸化水平。结果Fenu/L组、Fenu/H组小鼠的体重、空腹血糖、空腹血清胰岛素、HOMA-IR水平显著低于HFD组(P<0.05)。Fenu/L组、Fenu/H组小鼠的血清IL-1β、IL-6和MCP-1蛋白水平及皮下脂肪组织IL-1β、IL-6和MCP-1的mRNA表达水平显著低于HFD组(P<0.05)。Fenu/L组、Fenu/H组小鼠皮下脂肪组织中p-IRS-1、p-PI3K、p-Akt、GLUT4蛋白表达水平高于HFD组。Fenu/L组、Fenu/H组小鼠皮下脂肪组织中c-JUN、p-c-JUN、JNK和p-JNK蛋白表达水平低于HFD组。结论葫芦巴可通过抑制炎症因子(IL-1β、IL-6)及趋化因子(MCP-1)表达、限制JNK炎症信号通路的激活而表现出抗炎特性,也可通过降低空腹血糖、空腹血清胰岛素、HOMA-IR水平并诱导胰岛素受体信号通路的激活而表现出明显的改善胰岛素抵抗效应。

Objective To explore the mechanism of fenugreek in improving inflammation and insulin resistance in leptin-deficient ob/ob mice.Methods Mice were divided into normal diet group(NC group),high-fat diet group(HFD group),fenugreek low-dose treatment group(Fenu/L group),and fenugreek high-dose treatment group(Fenu/H group).After 12 weeks of the fenugreek intervention,body weights of the mice in each group were measured,blood lipid level of the mice were analyzed by an automatic biochemical analyzer,fasting blood glucose concentration of the mice were detected by a handheld blood glucose meter.Fasting serum insulin,serum interleukin(IL)-1β,IL-6 and monocyte chemotaxis protein(MCP)-1 levels of the mice were measured by enzyme linked immunosorbent assay(ELISA),and the homeostasis model assessment-insulin resistance(HOMA-IR)was calculated.The mRNA expression levels of IL-1β,IL-6,and MCP-1 in subcutaneous adipose tissue were measured by real time-quantitative polymerase chain reaction(RT-qPCR).The related protein phosphorylation level of the insulin receptor and c-Jun N-terminal kinase(JNK)inflammatory signaling pathway in subcutaneous adipose tissue were measured by western blot(WB).Results The levels of body weight,fasting blood glucose,fasting serum insulin and HOMA-IR in the Fenu/L group and the Fenu/H group were significantly lower than those of the HFD group(P<0.05).The protein levels in serum and the mRNA expression levels in the subcutaneous adipose tissue of IL-1β,IL-6,and MCP-1 in the Fenu/L group and Fenu/H groups were significantly lower than those of the HFD group(P<0.05).The protein expression levels of p-IRS-1,p-PI3K,p-Akt and GLUT4 in adipose tissue of Fenu/L group and Fenu/H group were higher than those of the HFD group.The protein expression levels of c-JUN,p-c-JUN,JNK and p-JNK in adipose tissue of Fenu/L group and Fenu/H group were lower than those of the HFD group.Conclusion Fenugreek could exhibit anti-inflammatory properties by inhibiting the expression of inflammatory cytokines(IL-1β,IL-6)and chemokines(MCP-1)and limiting the activation of the JNK inflammatory signaling pathway.It could also show a significant improved insulin resistance effect by lowering fasting blood glucose,fasting serum insulin,HOMA-IR levels,and inducing the activation of the insulin receptor signaling pathway.