Nrf2/HO-1通路在四神丸保护溃疡性结肠炎小鼠模型肠道损伤中的作用

Effect of Nrf2/HO-1 signaling pathway in intestinal protection by Sishen Pills against ulcerative colitis in mice

探讨核转录因子E2相关因子(nuclear factor erythroid 2 related factor 2,Nrf2)/血红素加氧-1(heme oxygenase-1,HO-1)信号通路在四神丸对溃疡性结肠炎肠道保护中的影响。建立3%葡聚糖硫酸钠(dextran sulfate sodium salt, DSS)诱导小鼠实验性溃疡性结肠炎模型,实验分为对照组、模型组、柳氮磺胺嘧啶(salazosulfapyridine, SASP)组以及四神丸高、低剂量组。造模同时给予灌胃给药,连续7 d,第7天实验结束时采集检测小鼠体质量、结肠长度变化情况和结肠病理改变,酶联免疫法检测血清中白细胞介素-6(interleukin-6,IL-6)、肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)、总抗氧化能力(total antioxidant capacity, T-AOC)、丙二醛(malondialdehyde, MDA)、活性氧(reactive oxygen species, ROS)变化情况,Western blot法和逆转录PCR法检测Nrf2、HO-1、醌氧化还原酶-1(NADPH quinine oxidoreductase-1,NQO-1)蛋白和mRNA表达的改变。结果表明,与对照组相比,模型组小鼠体质量和结肠长度明显减少,血清中IL-6、TNF-α、MDA、ROS含量明显升高,T-AOC含量明显降低,Nrf2、HO-1、NQO-1蛋白和mRNA表达水平明显降低。与模型组相比,SASP组和四神丸高剂量组小鼠体质量和结肠长度明显增加,血清中IL-6、TNF-α、MDA、ROS含量明显降低,T-AOC含量明显升高,Nrf2、HO-1、NQO-1蛋白和mRNA表达水平明显升高。病理结果显示,四神丸能改善小鼠结肠组织病理学变化。结果提示,四神丸能够抵抗3%DSS诱导的溃疡性结肠炎从而保护结肠损伤,其具体作用机制可能与激活Nrf2/HO-1信号通路发挥抗炎、抗氧化应激作用有关。

The present study aimed to explore the effect of nuclear factor erythroid 2 related factor 2(Nrf2)/heme oxygenase-1(HO-1) signaling pathway in intestinal protection by Sishen Pills against ulcerative colitis(UC). After the UC model was induced by 3% dextran sodium sulfate(DSS), experimental animals were randomly divided into control group, model group, salazosulfapyridine(SASP) group, and low-and high-dose Sishen Pills groups. Drug intervention(ig) was performed for seven consecutive days during modeling. On the 7 th day, the mice were euthanized. The body weight and colon length were recorded, and the histopathological changes of the colon were observed by HE staining. Serum interleukin-6(IL-6), tumor necrosis factor-α(TNF-α), total antioxidant capacity(T-AOC), malondialdehyde(MDA), and reactive oxygen species(ROS) were detected by ELISA. The protein and mRNA expression of Nrf2, HO-1, and NADPH quinine oxidoreductase-1(NQO-1) was determined by Western blot and reverse transcription-polymerase chain reaction(RT-PCR). Compared with the normal group, the model group exhibited reduced body weight, colon length, and T-AOC, increased IL-6, TNF-α, MDA, and ROS, and diminished protein and mRNA expression of Nrf2, HO-1, and NQO-1 in the colon tissues. Compared with the model group, the SASP group and high-dose Sishen Pills group showed elevated body weight, colon length, and T-AOC, lowered IL-6, TNF-α, MDA, and ROS levels, and increased protein and mRNA expression of Nrf2, HO-1, and NQO-1 in the colon tissues. As assessed by HE staining, Sishen Pills could improve the pathological changes of the colon. The findings suggested that Sishen Pills could protect the colon against UC induced by 3% DSS. The specific mechanism of action may be related to the anti-inflammatory and anti-oxidative stress effects by the activation of the Nrf2/HO-1 signaling pathway.