Abstract: To observe the protective effect of Chitosan ? Gentamicin conjugate（CS ? GT）on Dextran Sulfate Sodium（DSS）? induced colitis in mice. Thirty healthy SPF male C57BL / 6J mice were randomly divided into 5 groups：Control group，DSS group and low，medium and high dose CS?GT group. Taking daily clinical observation and recording of mice activity，diet，body weight and fecal occult blood. All animal were euthanized and blood，colon tissues were collected on the 14th day. The changes of intestinal mucosal，the concentration of serum biochemical indexes and inflammatory factors were determined by optical microscope，biochemical analyzer，and ELISA，respectively. The results showed that compared to the control group，the body weight，and colon length were decreased in DSS?treated mice（P<0.01）. Meanwhile，we observed serious bloody stool and intestinal villus dropped in this animal. The concentration of serum ALB and TP significantly decreased（P<0.01），as well as the decrease of anti? inflammatory factors IL?4 and IL?13. But the concentration of pro?inflammatory factor IL?6 was significantly increased （P<0.01）. Compared with DSS group，the body weight and colon length of mice in medium and high dose CS?GT groups were significantly increased（P<0.05），the bleeding was improved，and the level of serum ALB and TP increased significantly（P<0.05）. The expression level of pro?inflammatory factor IL?6 decreased significantly（P< 0.05），and the anti?inflammatory factors IL?4 and IL?13 trend to increase trendy. Our results suggested that CS?GT has a significant protective effect on DSS?induced colitis in mice and is valuable to development as a functional feed additive for animal intestinal protection.

Key words: Chitosan? Gentamicin conjugate； Ulcerative colitis； Inflammatory factors； Feed additive

摘要： 为观察壳聚糖接枝庆大霉素缀合物（CS?GT）对葡聚糖硫酸钠（Dextran sulfate sodium salt，DSS）诱导小鼠溃疡性结肠炎的保护效果。30只健康雄性小鼠（C57BL/6J，SPF级）随机平 均分为5组，分别为对照组、DSS组和CS?GT低、中、高剂量添加组。处理结束后，观察临床变 化、肠道结构、血清生化指标和炎性因子表达。结果发现，与对照组相比，DSS处理组小鼠体重 下降（P<0.01），结肠长度缩短（P<0.01），肠道出血及肠绒毛脱落，血清中ALB与TP含量显著 降低（P<0.01），促炎因子IL?6表达水平显著升高（P<0.01），抗炎因子IL?4和IL?13表达水平显 著降低（P<0.05）。而添加中、高剂量CS?GT组相较于DSS组小鼠体重显著上升（P<0.05）、结肠 长度显著增加（P<0.05），肠出血现象减少，血清中ALB与TP含量显著上升（P<0.05），促炎因 子IL?6表达水平显著下降（P<0.05），抗炎因子IL?4和IL?13有一定的上升趋势。说明CS?GT对 DSS诱导的小鼠结肠炎有明显保护效果，有望开发成动物肠道保护的功能饲料添加剂。

关键词: 壳聚糖接枝庆大霉素缀合物； 溃疡性结肠炎； 炎症因子； 饲料添加剂