润肠颗粒对小鼠便秘的改善作用及机制

Improvement effects of Runchang granules on the constipation in mice and its mechanism

目的探讨润肠颗粒对小鼠便秘的改善作用及潜在机制。方法将小鼠随机分为正常对照组、模型组、润肠颗粒低剂量组(5 g/kg)、润肠颗粒高剂量组(10 g/kg)和莫沙必利组(0.003 g/kg,阳性对照),每组6只。后4组小鼠灌胃洛哌丁胺(0.004 g/kg),每天2次,持续给药3 d后开始药物治疗,正常对照组和模型组小鼠灌胃纯水,各药物组小鼠灌胃相应药物,连续给药7 d。末次给药后,测定小鼠粪便含水量和肠道推进率,观察结肠和回肠组织结构以及结肠黏液分泌量,检测结肠组织中酪氨酸激酶受体c-kit、黏蛋白2(MUC2)、干细胞因子(SCF)蛋白表达水平以及炎症因子[肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)、IL-1β、诱导型一氧化氮合成酶(iNOS)]和促进肠道运动相关因子[神经型一氧化氮合酶(nNOS)、平滑肌肌球蛋白轻链激酶(smMLCK)、5-羟色胺受体4(5-HT4R)、MUC2、SCF、c-kit]mRNA表达水平。结果与模型组比较,润肠颗粒低、高剂量组和莫沙必利组小鼠粪便含水量,肠道推进率,结肠组织中c-kit蛋白表达水平和MUC2、SCF蛋白相对表达量以及促进肠道运动相关因子(润肠颗粒低剂量组nNOS和SCF除外)mRNA相对表达量均显著增加(P<0.05或P<0.01);炎症因子mRNA相对表达量均显著降低(P<0.05或P<0.01);结肠和回肠损伤均改善;润肠颗粒高剂量组小鼠结肠黏液分泌量显著增加(P<0.01)。结论润肠颗粒具有润肠通便的作用,能够改善小鼠便秘,其润肠机制可能与促进结肠黏液分泌和MUC2表达有关,其通便机制可能与激活SCF/c-kit信号通路有关。

OBJECTIVE To investigate the improvement effects of Runchang granules on the constipation in mice and its potential mechanism.METHODS The mice were randomly divided into normal control group,model group,Runchang granules low-dose and high-dose groups(5,10 g/kg),mosapride group(0.003 g/kg,positive control),with 6 mice in each group.The latter 4 groups were given loperamide intragastrically(0.004 g/kg),twice a day,for 3 consecutive days.Normal control group and model group were given purified water intragastrically,and administration groups were given relevant medicine intragastrically for 7 consecutive days.After the last medication,fecal moisture content and intestinal motility of mice were determined,while the structures of colon and ileum,and the secretion of colonic mucus were observed.Protein expressions of tyrosine kinase receptor(c-kit),mucin 2(MUC2)and stem cell factor(SCF)were determined in colon;meanwhile,the mRNA expression levels of inflammatory factors[tumor necrosis factor-α(TNF-α),interleukin-6(IL-6),IL-1β,inducible nitric oxide synthase(iNOS)]as well as factors related to promoting intestinal motility[neuronal nitric oxide synthase(nNOS),smooth muscle myosin light chain kinase(smMLCK),5-hydroxytryptamine 4 receptor(5-HT4R),MUC2,SCF,c-kit]were determined.RESULTS Compared with model group,the fecal water content,intestinal propulsion rate,protein expression of c-kit in colon,relative expressions of MUC2 and SCF protein,and mRNA expressions of factors related to promoting intestinal motility(except for nNOS and SCF in Runchang granules low-dose group)were all increased significantly in Runchang granules low-dose and high-dose groups,and mosapride group(P<0.05 or P<0.01).mRNA expression levels of inflammatory factors were decreased significantly(P<0.05 or P<0.01).Both colon and ileum injuries improved,and the secretion of colon mucus was increased significantly in Runchang granules high-dose group(P<0.01).CONCLUSIONS Runchang granules have laxative effect and can improve constipation in mice,and its mechanism may be related to the promotion of the secretion of colon mucus and MUC2 expression,and the activation of SCF/c-kit signaling pathway.