马齿苋多糖对溃疡性结肠炎大鼠肠组织IL-6/STAT3及NF-κB的影响

Effects of purslane polysaccharide on the intestinal tissue IL-6/STAT3 and NF-kappa B of ulcerative colitis

目的:采用TNBS(2,4,6-三硝基苯磺酸)复制溃疡性结肠炎大鼠模型,探索马齿苋多糖对溃疡性结肠炎大鼠肠组织IL6/STAT3及NF-κB的影响,明确IL-6/STAT3信号通路与慢性炎症性肠病发病的关系,为慢性溃疡性结肠炎的治疗寻找新靶点。方法:将40只SD大鼠随机分为对照组、模型组、美沙拉嗪组和马齿苋组(n=10)。采用TNBS诱导复制结肠炎模型,造模成功后第3天开始灌胃给药:美沙拉嗪组剂量为每次10 mg/kg,每日1次,连续3周;马齿苋组给予马齿苋多糖,每次10 ml/kg,每日1次,连续3周;模型组和对照组大鼠给予等体积生理盐水灌胃,每日1次,连续3周。收集大鼠结肠内容物称重,干燥后再次称重,取结肠组织作病理切片。采用ELISA试剂盒检测血清IL-6、IL-1β、TNF-α和核转录因子-kappa B(NF-κB)含量;免疫组化染色法测定结肠髓过氧化物酶(MPO);RT-PCR法检测信号转导和转录激活因子(STAT3)、IL-6的mRNA。结果:与模型组、美沙拉嗪组比较,马齿苋组大鼠排便状态明显改善,肠粘膜水肿减轻;血清IL-6、s IL-6Rα、gp130,肠组织MPO、NF-κB含量均降低(P<0.01)。与模型组比较,马齿苋组STAT3、IL-6mRNA的表达水平明显降低(P<0.01)。与对照组比较,上述指标无显著性差异(P>0.05)。结论:马齿苋多糖通过降低大鼠血清IL-6、s IL-6Rα、gp130含量及肠组织MPO、NF-κB水平,减轻s IL-6Rα与IL-6形成复合物所致的炎症反应;经IL-6/STAT3信号通路下调大鼠肠组织STAT3和IL-6的mRNA水平,从而抑制炎症的发生。

Objective： 2 minus 2-trinitrobenzene sulfonic acid（ TNBS） copy ulcerative colitis model of rats,to explore purslane polysaccharide on ulcerative colitis rats colon organization IL6/STAT3 and the influence of the NF-kappa B,clear IL-6/STAT3 signaling pathway and the relationship of chronic inflammatory bowel disease,looking for new targets for the treatment of chronic ulcerative colitis. Methods： Fourty rats were randomly divided into control group,model group,mesalazine group,and purslane group（ n =10）. The colonic contents were weighed and weighed again after drying,and the colonic tissues were biopsies. The contents of serum interleukin-6（ IL-6）,interleukin 1 β（ IL-1 β）,tumor necrosis factor α（ TNF-α）,nuclear transcription factor kappa B（ NF-kappa B） were detected by ELISA kit. Immunohistochemical staining was used to determine the colonic MPO（ myeloperoxidase）. RT-PCR method was used to detect signal transduction and transcriptional activator 3（ STAT3）,IL-6 mRNA. Results： Compared with model group and mesalazine group,defecation status of rats in purslane group were markedly improved,intestinal mucosa edema reduced,the serum IL-6,intestinal tissue MPO,the NF-kappa B and serum sIL-6 Rα,gp130 content were decreased（ P〈 0. 01）. Compared with the model group,the expression levels of STAT3 and IL-6 mRNA in the purslane group were significantly reduced（ P 〈0. 01）. There was no significant difference of testing indicator mentioned above between control group and purslane group（ P 〉0. 05）. Conclusion：By lowering the serum IL-6,sIL-6 Rα and gp130 in rats,the purslane polysaccharides reduced the levels of MPO and NF-kappa B in the intestinal tissues,and further reduced the inflammatory response caused by the formation of sIL-6 R alpha and IL-6. By using IL-6/STAT3 signaling pathway,the mRNA expression levels of STAT3 and IL-6 of rats intestinal tissues were down-regulated to inhibit the occurrence of inflammation.