双歧杆菌对实验性结肠炎中趋化因子的影响

Effect of Bifidobacterium on expression of inflammatory cytokine in experimental colitis rats

目的观察双歧杆菌在三硝基苯磺酸(TNBS)/乙醇诱导的实验性结肠炎的作用,并探讨其作用机制。方法 40只SPF级SD大鼠随机均分为正常组(N组)、模型组(M组)、双歧杆菌干预组(双歧杆菌预防性应用组:A组;双歧杆菌治疗组:B组)。TNBS/乙醇制备大鼠结肠炎模型。A组造模前7 d始予双歧杆菌0.1 mL,B组造模后予双歧杆菌0.1 mL,双歧杆菌悬液浓度:1×108 cfu/mL,正常组与模型组生理盐水2 mL,连续灌胃14 d。观察各组大鼠结肠炎疾病活动指数(DAI),评价结肠大体形态损伤指数(CMDI)和组织学损伤指数(TDI),免疫组织化学法检测结肠组织CCL20、CCR6的表达,ELISA法检测血清中CCL20、CCR6、TNF-α和IL-10含量。结果双歧杆菌干预组DAI、CMDI和TDI评分明显低于模型组,血清TNF-α、CCL20、CCR6及结肠组织CCL20、CCR6的表达明显降低(P均<0.01),而血清IL-10水平升高(P<0.01)。A组与B组差异无统计学意义。结论双歧杆菌可能通过降低组织及血清CCL20及其受体CCR6表达,调节促炎因子与抗炎因子的平衡,对实验性结肠炎发挥治疗作用,且提前应用能提高疗效,发挥更好的作用。

Objective To observe the preventive and therapeutic effect of Bifidobacterium on experimental rats with 2, 4, 6-trinitrobenzene sulfonic acid （TNBS）/ethanol induced colitis. Methods Forty rats were randomly divided into four groups （n = 10） ： normal control group （group N）, model group （group M）, Bifidobacterium prevention group （group A）, and Bifidobacterium treatment group （group B）. The colitis model of rats was established with TNBS/ethanol. Group A was fed with Bifidobacterium 0.1 mL for 7 days before to be molded, group B was given Bifidobacterium 0.1 mL after to be molded （the solution concentration of Bifidobacterium is 1 x 10s cfu/mL） , and group N and group M were given 2 mL normal saline. After continuous administration for 14 days, the colonic inflammation including disease activity index （DAI） , colonic macroscopic damage index （CMDI） and tissue damage index （TDI） were observed, the expression of CCL20 and CCR6 in the colon tissues of rats were detected by immunohistochemical method, the levels of CCL20, CCR6, TNF-α and IL-10 in serum were detected by ELISA. Results Compared with group M, the scores of DAI, CMDI and TDI, and the expressions of CCL20 and CCR6 in the colon tissues and the serum levels of CCL20, CCR6 and TNF-α significantly decreased in group A and group B （P 〈0.01 ）, while the serum level of IL-10 significantly increased （P 〈 0.01 ）. But the group A and group B had no significant difference. Conclusion Bifidobacterium possiblely produces prevention and treatment effect in experimental colitis rats by regulating the dynamic balance between proinflammatory and inflammation cytokines. Furthermore, Bifidobacterium in advance can improve the effectiveness and perform better.