薯蓣皂苷激活PERK-Nrf2-HO-1通路改善糖尿病小鼠胰岛素抵抗的机制探究

Mechanism of dioscin in activating PERK-Nrf2-HO-1 pathway to improve insulin resistance in diabetic mice

目的 基于蛋白激酶R样内质网激酶(PERK)/核转录因子E2相关因子2(Nrf2)/血红素加氧酶-1(HO-1)通路的抗氧化作用,研究薯蓣皂苷改善糖尿病小鼠胰岛素抵抗(IR)的作用机制。方法 将小鼠随机分成对照组,糖尿病组(建模),薯蓣皂苷低剂量组(建模+25 mg/kg薯蓣皂苷)、薯蓣皂苷中剂量组(建模+50 mg/kg薯蓣皂苷)、薯蓣皂苷高剂量组(建模+100 mg/kg薯蓣皂苷)和二甲双胍组(建模+100 mg/kg二甲双胍),各组小鼠9只。药物处理30 d后,对各组小鼠空腹血糖(FBG)、空腹胰岛素(FINS)、胰岛素抵抗指数(HOMA-IR)和体重进行检测;通过HE染色检测小鼠肝脏组织病理学情况;通过试剂盒检测肝脏组织超氧化物歧化酶(SOD)活性、丙二醛(MDA)和活性氧自由基(ROS)水平及肝脏细胞凋亡指数(AI);通过Western blot检测肝脏组织中PERK、Nrf2、HO-1及凋亡相关蛋白Bax、cleaved caspase-6的表达情况。结果 与对照组相比,糖尿病组小鼠FBG、FINS、MDA、ROS、AI及Bax、cleaved caspase-6蛋白表达水平均明显升高(P<0.05);而体重、SOD活性及PERK、Nrf2、HO-1蛋白表达水平均明显降低(P<0.05)。与糖尿病组相比,薯蓣皂苷组能够明显降低糖尿病小鼠FBG、FINS、HOMA-IR、MDA、ROS、AI及Bax、cleaved caspase-6蛋白表达水平(P<0.05),明显提高小鼠体重、SOD活性及PERK、Nrf2、HO-1蛋白表达水平(P<0.05)。结论 薯蓣皂苷能够通过激活PERK-Nrf2-HO-1信号通路,减轻氧化应激及肝脏细胞凋亡,改善糖尿病小鼠胰岛素抵抗。

Objective Based on the antioxidant effect of protein kinase R-like endoplasmic reticulum kinase(PERK)/nuclear transcription factor E2 related factor 2(Nrf2)/heme oxygenase-1(HO-1)pathway, to study the mechanism of dioscin in improving insulin resistance(IR)in diabetic mice.Methods Mice were randomly divided into control group, diabetes group(modeling),low dose dioscin group(modeling+25 mg/kg dioscin),medium dose dioscin group(modeling+50 mg/kg dioscin),high dose dioscin group(modeling+100 mg/kg dioscin) and metformin group(modeling +100 mg/kg metformin),with 9 mice in each group.After 30 days of drug treatment, the fasting blood glucose(FBG),fasting insulin(FINS),insulin resistance index(HOMA-IR)and body weight of mice in each group were determined;the histopathology of mouse liver was detected by HE staining;the liver tissue SOD activity, MDA and ROS levels and liver cell apoptosis index(AI)were detected through the kits;the expression of PERK,Nrf2,HO-1 and apoptosis-related proteins Bax and cleaved caspase-6 in liver tissues was detected by Western Blot.Results Compared with the control group, the FBG,FINS,MDA,ROS,AI,expression levels of Bax and cleaved caspase-6 proteins in the diabetic group were significantly increased(P<0.05);the body weight, SOD activity and expression levels of PERK,Nrf2,and HO-1 proteins were significantly reduced(P<0.05).Compared with the diabetes group, the dioscin group could significantly reduce the FBG,FINS,HOMA-IR,MDA,ROS,AI,and the expression levels of Bax and cleaved caspase-6 proteins(P<0.05),and significantly improve the body weight, SOD activity, and the expression levels of PERK,Nrf2,and HO-1 proteins of the mice(P<0.05).Conclusion Dioscin can reduce oxidative stress and liver cell apoptosis by activating the PERK-Nrf2-HO-1 signaling pathway, and improve IR in diabetic mice.