Objectives: To observe the effect of moxibustion with seed-size moxa cones on the Toll-like receptor 4(TLR4)/myeloid differentiation factor 88(MyD88)/nuclear transcription factor-κB(NF-κB) signaling pathway in mice with ulcerative colitis(UC), so as to explore the therapeutic mechanism of moxibustion with seed-size moxa cones on colonic injury in UC.
Methods: Forty male C57BL/6 mice were randomly divided into blank group, model group, moxibustion group, and western medicine group, with 10 mice in each group. The UC mouse model was established by 3% DSS solution by free drinking for 7 consecutive days. Mice in the moxibustion group were treated with seed-size moxa cones at "Zhongwan"(CV12), "Tianshu"(ST25) and "Shangjuxu"(ST37), 3 moxa cones per point, with each cone applied for approximately 30 s, while mice in the western medicine group were orally administered with 300 mg/kg mesalazine solution, which were both conducted once a day for 7 consecutive days. The general condition of mice was observed every 2 days, and the disease activity index (DAI) score was calculated. HE staining was used to observe the morphology of colonic tissue in mice. ELISA was used to detect the serum interleukin(IL)-1β, tumor necrosis factor(TNF)-α, IL-6, and IL-8 contents. Immunohistochemistry was used to detect the positive expression of TLR4 and MyD88 in colonic tissue of mice. Real-time fluorescence quantitative PCR was used to detect the expression levels of TLR4, MyD88, and NF-κB p65 mRNAs in colonic tissue.
Results: Compared with the blank group, varying degrees of soft or watery stools were observed, colon length and body weight were decreased(P<0.01) in mice of the model group, while DAI score, colon weight index, mucosal damage score, colonic pathological score, serum IL-1β, TNF-α, IL-6, and IL-8 contents, positive expressions of TLR4 and MyD88, and TLR4, MyD88, and NF-κB p65 mRNA expressions in colonic tissue were increased(P<0.01). Compared with the model group, improved fecal characteristics were observed, colon length and body weight were increased(P<0.01) in mice of the moxibustion group and western medicine group, while DAI scores, colon weight indexes, mucosal damage scores, colonic pathological score, serum contents of IL-1β, TNF-α, IL-6, and IL-8, positive expressions of TLR4 and MyD88, and TLR4, MyD88, and NF-κB p65 mRNA expressions in colonic tissue were decreased(P<0.01, P<0.05). There was no significant difference in the above indicators between the moxibustion group and the western medicine group.
Conclusions: Moxibustion with seed-size moxa cones may alleviate colonic injury in UC mice by regulating the TLR4/MyD88/NF-κB signaling pathway and reducing the release of inflammatory factors.
目的: 观察麦粒灸对溃疡性结肠炎（UC）小鼠Toll样受体4（TLR4）/髓样分化因子88（MyD88）/核转录因子κB（NF-κB）信号通路的影响，探讨麦粒灸对UC结肠损伤的治疗机制。方法: C57BL/6雄性小鼠随机分为空白组、模型组、麦粒灸组、西药组，每组10只。采用连续7 d自由饮用3% DSS溶液法制备UC小鼠模型。麦粒灸组予麦粒灸“中脘”“天枢”“上巨虚”治疗，每穴3壮，每壮时间约为30 s。西药组给予300 mg/kg美沙拉嗪肠溶片溶液灌胃。各组干预均1次/d，连续7 d。每隔2 d观察小鼠一般情况，计算小鼠疾病活动指数（DAI）评分；HE染色法观察小鼠结肠组织形态；ELISA法检测血清白细胞介素（IL）-1β、肿瘤坏死因子α（TNF-α）、IL-6和IL-8的含量；免疫组织化学法检测小鼠结肠组织中TLR4、MyD88的阳性表达；实时荧光定量PCR法检测小鼠结肠组织中TLR4、MyD88、NF-κB p65 mRNA的表达水平。结果: 与空白组比较，模型组小鼠出现不同程度的软便或稀便，结肠长度缩短（P<0.01）、体质量下降（P<0.01），DAI评分、肠重指数、黏膜损伤评分、结肠病理评分及血清IL-1β、TNF-α、IL-6和IL-8含量升高（P<0.01），结肠组织中TLR4、MyD88阳性表达及TLR4、MyD88、NF-κB p65 mRNA的表达均升高（P<0.01）；与模型组比较，麦粒灸组、西药组小鼠粪便性状得到了改善，结肠长度增加（P<0.01）、体质量升高（P<0.01），DAI评分、肠重指数、黏膜损伤评分、结肠病理评分及血清IL-1β、TNF-α、IL-6和IL-8含量降低（P<0.01，P<0.05），结肠组织中TLR4、MyD88阳性表达及TLR4、MyD88、NF-κB p65 mRNA的表达均下降（P<0.05，P<0.01）；麦粒灸与西药组相比，以上指标差异无统计学意义。结论: 麦粒灸可能通过调控TLR4/MyD88/NF-κB信号通路，减少炎性因子的释放，从而改善UC小鼠的结肠损伤。.
Keywords: Colonic injury; Inflammatory response; Moxibustion with seed-size moxa cones; TLR4/MyD88/NF-κB signaling pathway; Ulcerative colitis.