关键词: 日本血吸虫；半胱氨酸蛋白酶抑制剂；葡聚糖硫酸钠；溃疡性结肠炎

Abstract: Objective To investigate the effect of cysteine protease inhibitor derived from Schistosoma japonicum （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]） （F = 86.86， P < 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 （F = 86.86， P < 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 （F = 17.46 and 9.89， both P < 0.01）. Conclusion SjCystatin has a significantly inhibitory effect for alleviating DSS?induced acute ulcerative colitis in C57BL/6 mice.

Key words: Schistosoma japonicum； Cysteine protease inhibitor； Dextransulphate sodium； Ulcerative colitis