**4. Preventive effect of CNF on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC)**

In this section we describe the medical aspect of CNFs taking a model of DSS- induced colitis in mouse as investigated by Azuma et al [4]. The effect of CNFs on disease activity index such as weight loose, loose stools, and bleeding symptoms in colitis were studied. CNFs adminis‐ tered mouse exhibited a significant reduced in disease activity index. Colon length increased that was shortened due to DSS induction by administration of CNFs compared to control. Damage in intestinal mucosa was microscopically monitored as shown in Fig. 16. In CNFs group on 6th day erosion, crypt destruction, and edema were markedly suppressed compared to control. The number of myeloperoxidase (MPO)-positive cells lowered significantly compared to control group. Thus CNFs improved clinical symptoms in DSS-induced acute UC mouse model.

**Figure 16.** Effect of CNFs administration on histopathologicucedal changes in DSS-induced acute UC mice; a) control, b) CNFs, and c) chitin powder. Reproduced with permission from ref. 4. Copyright 2012, Elsevier.
