基于TLR4/NF-κB 信号通路探讨荆芥连翘汤对溃疡性结肠炎大鼠的作用及机制

目的：观察荆芥连翘汤对溃疡性结肠炎（UC）大肠湿热证大鼠的作用，并基于Toll样受体4/核因子κB（TLR4/NF-κB）信号通路探索其机制。方法：将55只SPF级雄性SD大鼠随机分为5组（对照组、模型组、西药组、灌胃组、灌肠组），对除对照组外的其余组制备溃疡性结肠炎大肠湿热证大鼠模型。造模成功后，西药组予美沙拉嗪灌肠液(0.4 g/kg·d)灌肠，灌胃组、灌肠组分别予荆芥连翘汤（36.84 g/kg·d）灌胃（分2次给药）、灌肠；对照组、模型组均予0.9%氯化钠注射液灌肠。观察大鼠一般行为变化并进行疾病活动指数(DAI)评分，采用苏木精-伊红染色观察大鼠结肠病理改变情况，采用酶联免疫吸附法检测血清白细胞介素-1β（IL-1β）、肿瘤坏死因子-α（TNF-α）、白细胞介素-10（IL-10）的表达，免疫组化检测大鼠结肠黏膜中NF-κB、TLR4的蛋白表达情况，qRT-RCR检测TLR4 mRNA的表达，分析TLR4/NF-κB 信号通路的活化情况。结果：与模型组相比，西药组、灌肠组、灌胃组的 DAI评分降低（P<0.05），结肠组织炎细胞浸润情况改善，肠黏膜趋于正常；IL-10升高，TNF-α、TLR4、NF-κB、TLR4 mRNA表达降低，差异均有统计学意义（P<0.05）。西药组、灌肠组IL-1β较模型组降低（P<0.05）。结论：荆芥连翘汤对溃疡性结肠炎大肠湿热证大鼠具有较好的改善症状及抑制炎症作用，其可能通过抑制TLR4/NF-κB信号通路而发挥作用。

Role and mechanism of Jingjie Lianqiao decoction in rats with ulcerative colitis based on the Toll-like receptor 4/nuclear factor-kappa B signaling pathway

Objective：To investigate the role of Jingjie Lianqiao decoction on ulcerative colitis (UC) rats with large intestine damp-heat syndrome and its mechanism based on the Toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB) signaling pathway.Methods：A total of 55 specific pathogen-free male Sprague-Dawley rats were randomly divided into control group，model group，Western medicine group，gavage group，and enema group，and all rats except those in the control group were used to establish a rat model of UC with large intestine damp-heat syndrome.After successful modeling，the rats in the Western medicine group were given enema with mesalazine enema fluid (0.4 g/kg·d)，those in the gavage group and the enema group were given intragastric administration (in two divided doses) of Jingjie Lianqiao decoction or enema with Jingjie Lianqiao decoction at a dose of 36.84 g/kg·d，and those in the control group and the model group were given enema with 0.9% sodium chloride injection.The changes in general behaviors were observed，and disease activity index (DAI) was determined；HE staining was used to observe the pathological changes of the colon；ELISA was used to measure the expression levels of interleukin-1β (IL-1β)，tumor necrosis factor-α (TNF-α)，and interleukin-10 (IL-10) in serum；immunohistochemistry was used to measure the protein expression levels of NF-κB and TLR4 in colonic mucosa，and qRT-RCR was used to measure the mRNA expression level of TLR4；the activation of the TLR4/NF-κB signaling pathway was analyzed.Results：Compared with the model group，the Western medicine group，the enema group，and the gavage group had a significant reduction in DAI score (P<0.05)，with improvement in inflammatory cell infiltration in colonic tissue and basically normal intestinal mucosa，as well as a significant increase in IL-10 and significant reductions in the mRNA expression levels of TNF-α，TLR4，NF-κB，and TLR4 (P<0.05).The Western medicine group and the enema group had a significant reduction in IL-1β compared with the model group (P<0.05).Conclusion：Jingjie Lianqiao decoction can improve symptoms and inhibit inflammation in UC rats with large intestine damp-heat syndrome，possibly by inhibiting the TLR4/NF-κB signaling pathway.