The Role Of Chitosan On The DSS-induced Colitis Model

Chitosan which is derived from the partial deacetylation of chitin, is the onlycatnic polysaccharide in nature, it exhibits many particular phys chem properties andbioactivities. In previous, Chitosan has been found it had the effect of enhancingimmune responses, for example, activiting resident macrophage. But in currentresearch, we found that Chitosan also played an important role in curing woundhealing and inflammation diseases like trachitis, indicting Chitosan could alsoattenuate stimulated macrophage.In this study, we established the DSS induced colitis model with Cooper method.32 Balb/c rats (the number of males and females are the same) were divided into 4groups randomly which named A, B, C and D respectively. The mice group A wastreated with distilled water, meanwhile the mice group B, C, and D were treated with5mg/mL、10mg/mL、15mg/mL Water Soluble Chitosan(WSC) respectively. And thenboth were given 0.5ml per day until eleven days while 5% DSS treated seven days.The experiment results are given in the following: (1) the DAI value decreasedobviously after 7 day, and after 11 days group D had the lowest DAI value; (2) theactivity of MPO of group B, C and D were all reduced in comparison with group A,and group D was dropped obviously in comparison with group A; (3) the length ofcolon of group D were longer in comparison with group A with notability; (4) WaterSoluble Chitosan(WSC)treated colonic tissue H.E stain showed that there were someameliorations in a certain extent in the area of ulceration, soakage of inflammationcells, turbulence of epithelium and damage of the recess, and among them theamelioration of group D was the best.In addition, we study the the immunomodulatory effects of water-solublechitosan on the LPS activated macrophages. Different concentration of WSC wereadded to LPS stimulated macrophage for 6h. 6h later, the expression of IL-6-mRNA,TNF-α-mRNA, and iNOS-mRNA were detected by RT-PCR. Results showed thatcompared to LPS group, WSC could decrease the expression of inflammatory factors. At the same time, we found WSC can reduce the release of NO.In summary, chitosan can alleviate the clinical symptoms of DSS-induced colitismodel, and have therapeutic effect on colitis. Its mechanism may be through theregulation of activated macrophages. In-depth study of the immunomodulatory effectsof chitosan, contribute to the further development of the chitosan.