荆芥、防风对溃疡性结肠炎大鼠结肠黏膜AQP4和AQP8表达的影响

探讨荆芥、防风对溃疡性结肠炎(ulcerative colitis, UC)大鼠结肠黏膜水通道蛋白(aquaporin,AQP)4和AQP8表达的影响。SD雄性健康大鼠共35只,随机分为正常组、模型组和风药(荆芥、防风免煎颗粒1∶1)低、中、高剂量组(6,12,24 g·kg-1·d-1),每组7只。除正常组外,其余组大鼠均采用3%葡聚糖硫酸钠(DSS)溶液连续自由饮用复制UC大鼠模型,造模10 d后予以灌胃给药,正常组和模型组均予以生理盐水,连续灌胃10 d,实验期间观察大鼠一般状况,分别于10 d后结束实验时采集结肠组织,测量各组大鼠结肠长度,评估结肠黏膜损伤指数(CMDI)及结肠病理变化评分,ELISA法检测血清IL-1和IL-8含量变化,免疫组化法检测结肠组织内AQP4和AQP8蛋白表达情况,PCR法检测结肠黏膜AQP4和AQP8 mRNA的表达情况。与正常组比较,模型组大鼠结肠长度明显短缩(P<0.01),CMDI及病理评分显著增加(P<0.01),血清IL-1和IL-8含量明显增加(P<0.05),免疫组化结果显示蛋白表达较低,颜色为淡黄色或棕色,AQP4和AQP8 mRNA表达明显降低(P<0.01);与模型组比较,风药组CMDI及病理评分、血清IL-1和IL-8含量明显降低(P<0.01,P<0.05),免疫组化结果显示蛋白表达较强,颜色为棕褐色或深褐色,结肠长度及AQP4和AQP8 mRNA表达增加(P<0.01,P<0.05)。荆芥和防风对UC模型大鼠症状及病理组织有明显的改善作用,促进肠黏膜修复,其机制可能与上调结肠AQP4和AQP8表达相关。

Effect of Schizonepetae Herba and Saposhnikoviae Radix on expression of AQP4 and AQP8 in colonic mucosa of rats with ulcerative colitis

The aim of this paper was to investigate the effect of Schizonepetae Herba and Saposhnikoviae Radix(wind medicine) on the expression of AQP4 and AQP8 in colonic mucosa in rats with ulcerative colitis(UC). A total of 35 healthy SD male rats were randomly divided into normal group(gavaged with normal saline), DSS model group, as well as low, middle, and high dose wind medicine groups(Schizonepeta and Saposhnikovia 1∶1, gavaged at dosages of 6, 12, and 24 g·kg-1·d-1), with 7 in each group. UC rat model was established by free drinking of 3% dextran sulphate sodium(DSS) solution for 10 days. At the end of the 10 th day after the treatment, mice were put to death to collect colonic mucosa. The length of colon was measured;the colonic mucosal injury index(CMDI) and pathological changes of colon were observed. ELISA method was used for measuring the content of serum IL-1, IL-8, and immunohistochemical method was used to measure AQP4, AQP8 protein expressions in colon mucosa. The expressions of AQP4, AQP8 mRNA were measured by Real-time PCR. As compared with the normal group, the length of colon tissue was significantly reduced(P<0.01), CMDI scores and pathological scores were significantly increased(P<0.01), the levels of serum IL-1 and IL-8 were significantly increased(P<0.05) in model group;the immunohistochemical results showed that the protein expressions of AQP4, AQP8 were lower;the color was light yellow or brown;AQP4, AQP8 mRNA expressions in colon mucosa were significantly decreased in model group(P<0.01). CMDI scores, pathological scores, and the levels of serum IL-1, IL-8 in high, middle, low dose wind medicine groups were obvious lower than those in the model group(P<0.01 or P<0.05);the protein expressions of AQP4, AQP8 were higher;the color was chocolate brown or dark brown;the length of colon tissue, and the expressions of AQP4, AQP8 mRNA were obvious higher in wind medicine groups(P<0.01 or P<0.05). Schizonepetae Herba and Saposhnikoviae Radix could significantly improve the symptoms and histopathology of UC model rats and accelerate the intestinal mucosal healing. The mechanism may be related with up-regulating the expression level of AQP4 and AQP8 in colonic mucosa.