塞来昔布灌肠对溃疡性结肠炎小鼠肠黏膜异型增生的防治作用

Prevention and treatment effects of celecoxib via coloclysis in mice with ulcerative colitis associated intestinal mucosa dysplasia

目的探讨不同浓度塞来昔布灌肠对溃疡性结肠炎小鼠肠黏膜异型增生的防治作用,并分析其可能的作用机制。方法 60只C57BL/6雄性小鼠随机分为6组(每组10只):塞来昔布高、中、低剂量组(A、B、C组)、美沙拉秦组(D组)、模型组(E组)、空白组(F组)。氧化偶氮甲烷/葡聚糖硫酸钠(AOM/DSS)复合法制备实验模型,建模第5天,A、B、C组分别给予1.5 mg/ml、1.0 mg/ml、0.5 mg/ml剂量的塞来昔布灌肠,D组给予美沙拉秦灌肠液灌肠,E组给予同等剂量0.9%氯化钠注射液灌肠。治疗23 d后处死小鼠,肉眼观察结肠组织变化,镜下观察结肠病理改变及免疫组化COX-2、CDX-2、BCL-2的表达,Elisa法检测血清细胞因子水平。结果肉眼观察A、B组较E组结肠表面光滑,血管纹理清晰,C、D组结肠表面欠光滑,粪便较成型;HE染色A、B两组黏膜较完整,腺体排列整齐,C组以浅表溃疡为主,D组偶有淋巴细胞浸润,E组以慢性炎症伴轻-中度异型增生为主;各治疗组血清细胞因子IL-6、TNF-α的含量较E组均有下降,其中A、B组TNF-α下降明显(P<0.05);免疫组化检测COX-2显示A、B组评分明显低于C、D、E组,BCL-2显示A、B、D组评分较C、E组低,CDX-2显示A、B、C、D组评分较E组评分明显升高(P<0.05)。结论塞来昔布灌肠具有防治溃疡性结肠炎小鼠肠黏膜异型增生的作用,其中以高、中剂量效果明显;机制可能与下调COX-2、BCL-2的表达,减少IL-6、TNF-α等炎性因子的生成有关。

Objective To compare the prevention and treatment effects of different concentrations of celecoxib via coloclysis in mice with ulcerative colitis associated intestinal mucosa dysplasia and analyze the possible mechanism. Methods Sixty C57BL/6 male mice were randomly divided into six groups（n=10）： the high（A）, middle（B）, low（C） doses of celecoxib groups, mesalazine group（D）, model group（E）, blank group（F）. Azoxymethane / Dextran sulfate sodium（AOM/DSS） combined technique was used to establish the experimental mouse mode. After modeling for five days, the mice were treated accordingly： mice in experimental group A, B, C were given the high, medium and low doses of celecoxib（1.5 mg/m L, 1.0 mg/m L, 0.5 mg/m L） via coloclysis, mice in group D were given mesalazine via coloclysis, mice in group E were given the same dose of 0.9% sodium chloride injection via coloclysis. The mice were sacrificed at day 23 after treatment, the changes of colon tissue were observed with naked eyes, and the differences of colon pathological changes and expression of immunohistochemistry COX-2, CDX-2, BCL-2 were assayed under microscope. Meanwhile, the levels of serum cytokines were detected by Elisa. Results Visually, compared with group E, the colon surface of group A and B were smoother and the vascular texture were clearer. In group C and D, the colon surface was less smooth, while the stool was relatively forming. HE staining showed that there were more complete mucosa, neater glands in group A and B. However, the major types of group C was superficial ulcer, group D was causally with lymphocyte infiltration, group E was mainly chronic inflammation associated with light to moderate hyperplasia. The serum inflammatory cytokines IL-6, TNF-α content of each treatment group declined significantly（P〈 0.05）, the result of immunohistochemical detection showed that COX-2 scores of group A and B were significantly lower than group C, D, E, BCL-2 scores of group A, B, D were significantly lower than group C, E, CDX-2 scores of group A, B, C, D was significantly higher than group E（P〈 0.05）. Conclusion Celecoxib via coloclysis has the effect on prevention and treatment of ulcerative colitis associated intestinal mucosa dysplasia and the effect of middle and high dose is obvious, meanwhile, the mechanism may be related with a down-regulation in the expression of COX-2, BCL-2, and the reduction of production of inflammatory factors IL-6, TNF-α.