益气化浊汤经PI3K/Akt通路减轻氧化应激治疗2型糖尿病大鼠胰岛素抵抗

Yiqi Huazhuo Decoction alleviates oxidative stress through PI3K/Akt pathway to treat insulin resistance in T2DM rats

关键词:  益气化浊汤  ROS  MDA  SOD  肝胰岛素抵抗

Key words:  Yiqi Huazhuo Decoction  ROS  MDA  SOD  hepatic insulin resistance

摘要:

[目的] 本研究旨在探讨益气化浊汤(YD)治疗伴有胰岛素抵抗(IR)的2型糖尿病(T2DM)大鼠的作用及其机制。[方法] 建立2个YD干预组[低剂量YD组，15 mg/(kg·d)；高剂量YD组，30 mg/(kg·d)]，测定大鼠血糖、血清胰岛素、血脂水平，计算胰岛素抵抗(HOMA-IR)指数，采用生化法检测超氧化物歧化酶(SOD)、丙二醛(MDA)水平，免疫荧光法检测活性氧(ROS)水平，蛋白免疫印迹法(Western blot)检测肝组织磷脂酰肌醇3激酶(PI3K)及蛋白激酶B (Akt)活性，观察YD干预对PI3K-p85、Akt蛋白活性、下游各氧化应激因子及肝组织损伤变化的影响。[结果] YD可显著降低T2DM-IR大鼠的血糖、HOMA-IR指数与血脂水平，高剂量YD可升高SOD水平至模型组138.3%，分别降低MDA及ROS水平至模型组的43.4%及45.2%，降低肝组织病理评分至模型组的46.6%，且肝脏p-PI3K-p85^Tyr458/PI3K-p85及p-Akt^S473/Akt的蛋白相对表达量比值均明显升高，高剂量YD的上述蛋白比值分别为模型组的316.6%及248.8%。[结论] YD可通过调节机体的糖脂代谢，减轻氧化应激给胰岛素靶器官肝脏带来的损伤，改善肝IR。YD调节肝IR的机制可能是通过激活PI3K/Akt通路，调节下游蛋白以及抗氧化酶的表达来实现。

Abstract:

[Objective] This study aimed to investigate the effect and mechanism of Yiqi Huazhuo decoction(YD) in treating insulin resistance(IR) in rats with type 2 diabetes mellitus(T2DM). [Methods] The low-dose YD group[15 mg/(kg·d)] and the high-dose YD group[30 mg/(kg·d)] were established as two intervention groups in this study. Blood glucose,serum insulin,and blood lipid levels of rats in the high-dose YD group were measured,and the homeostasis model assessment-insulin resistance(HOMA-IR) index was calculated. superoxide dismutase(SOD) and malondialdehyde(MDA) levels were determined using a biochemical method,while reactive oxygen species(ROS) levels were measured using an immunofluorescence method. Western blot analysis was conducted to assess the activity of phosphatidylinositol 3-hydroxy kinase(PI3K) and protein kinase B(Akt),aiming to observe the effects of YD intervention on PI3K-p85,Akt protein activity,downstream oxidative stress factors,and liver tissue injury. [Results] YD significantly reduced blood glucose levels,HOMA-IR index,and blood lipid levels in T2DM-IR rats. High-dose YD increased SOD level by 138.3% compared to the model group；it also decreased MDA and ROS levels by 43.4% and 45.2%,respectively. Additionally,high-dose YD reduced liver histomorphological score by 46.6% in the model group. Furthermore,there was a significant increase in relative expression ratio of p-PI3K-p85^Tyr458/PI3K-p85 and p-Akt^S473/Akt proteins in liver tissues；these ratios reached 316.6% and 248.8%,respectively for high-dose YD within the model group. [Conclusion] YD can reduce damage caused by oxidative stress to the insulin target organ-liver-and improve liver IR by regulating glucose and lipid metabolism. The mechanism through which YD regulates hepatic IR may involve activating PI3K/Akt pathway as well as regulating downstream proteins’ expression along with antioxidant enzymes.