[Effect of cystatin from on DSS - induced ulcerative colitis in mice].

Objective: To investigate the effect of cysteine protease inhibitor derived from (SjCystatin) on dextran sodium sulfate (DSS)-induced acute ulcerative colitis in mice.

Methods: Eighteen C57BL/6 mice were randomly divided into three groups: a control group treated with PBS (Group A), a DSS-induced-colitis group treated with PBS (Group B), and a DSS-induced-colitis group treated with SjCystatin (Group C). Colitis was induced in mice by giving 3% DSS orally for 7 days. During this period, the mice were daily injected with 10 μg of SjCystatin or PBS only as a control intraperitoneally. The mice were monitored daily for their clinical manifestations and given scores based on disease activity index (DAI). The severity of colonic inflammation was monitored by the macroscopic score and pathological change. The cytokine profile including TNF-α, IL-4, IL-6 and IL-10 in the supernatants of colon homogenate was detected by ELISA.

Results: Compared with Group A (0.50 ± 0.28), the DAI score increased significantly in Group B (9.30 ± 1.30) ( = 86.86, < 0.01), with remarkable pathological damages seen in colon tissues. and the levels of TNF-α and IL-6 were (321.33±67.01) and (403.58 ±180.51) pg/mL. The DAI score significantly reduced in Group C (6.67±1.57) as compared to Group B ( = 86.86, < 0.01), with improvements in the macroscopic and microscopic pathology in mouse colon specimens. As compared to Group B, the levels of TNF-α [(188.14 ± 40.14) pg/mL] and IL-6 ([ 209.71 ± 48.47) pg/mL] significantly decreased ( = 17.46 and 9.89, both < 0.01).

Conclusions: SjCystatin has a significantly inhibitory effect for alleviating DSS-induced acute ulcerative colitis in C57BL/6 mice.