中文摘要：

[目的]探讨桦褐孔菌多糖对葡聚糖硫酸钠（DSS）诱导的急性炎症性肠病（IBD）模型小鼠的影响.[方法]取7周龄Balb/c雄性小鼠,随机分为正常对照组、模型对照组和实验组.每日灌胃给予实验组小鼠200mg/kg桦褐孔菌多糖,给模型对照组和实验组小鼠自由饮用3.5%（质量分数）DSS溶液7d,第8d饮用纯净水,正常对照组一直自由饮用纯净水.每天测量体质量,于实验第9d处死小鼠取结肠,测量结肠长度,并进行结肠黏膜大体形态学和组织学评分.用半定量RT-PCR法测定结肠组织和肠系膜淋巴结（MLN）中肿瘤坏死因子（TNF）-α和白细胞介素（IL）-17的表达水平.[结果]模型对照组和实验组体质量均下降,但与模型对照组比较,实验组小鼠体质量下降幅度减小,于实验第7～9 d,两组体质量下降幅度间差异有统计学意义（P〈0.05）.模型对照组结肠平均长度较正常对照组明显减少（P〈0.01）,而实验组结肠平均长度较模型对照组缩短程度明显减轻（P〈0.05）.实验组结肠大体和组织学评分均明显低于模型对照组（P〈0.05）,结肠组织和MLN中TNF-α和IL-17 mRNA表达均少于模型对照组.[结论]桦褐孔菌多糖对DSS诱导的急性IBD模型小鼠具有治疗作用,其机制认为可能与下调结肠组织和MLN中促炎细胞因子TNF-α和IL-17表达有关系.

英文摘要：

OBJECTIVE To explore the effects of Inonotus obliquus polysaccharide on acute inflammatory bowel disease（IBD）induced by DSS in mice.METHODS7 weeks old male Balb/c mice were selected,they were randomly divided into control,DSS and experiment groups.The mice in the DSS and experiment group were fed with 3.5%（W/V）DSS solution for 7days,and the mice in the control group were given purified water,and at the same time the mice in the experiment group were given 200mg/kg Inonotus obliquus polysaccharide by gavage every day.The weight of mice was measured.The mice colon was taken out after execution on the 9th day.Colonic lengths were measured and the general morphology and histology of colonic mucosa were graded.Furthermore,the mRNA expression of tumor necrosis factor（TNF）-αand interleukin（IL）-17 in colon and mesenteric lymph nodes（MLN）were also determined by reverse transcription-polymerase chain reaction（RT-PCR）.RESULTS The average weight in the DSS and experiment group was down,but as compared with the DSS group,the descent range of weight was decreased in the experiment group,there was significant difference of the average weight in the two groups on the 7-9d（P〈0.05）.Colonic length in the DSS group was significantly shorter than that in the control group（P〈0.01）,while colonic length in the experiment group was longer than that in the DSS group（P〈0.05）.The scores of the colon general morphology and histology in the experiment group were inferior to that in the DSS group（P〈0.05）.The mRNA expression of TNF-αand IL-17 in colon and MLN in the experiment group were also significantly lower than those in the DSS group.CONCLUSIONInonotus obliquus polysaccharide had the curative effects on acute IBD induced by DSS,and the mechanism might be related with the down regulation of pro-inflammatory cytokines TNF-αand IL-17 in colon and MLN.