Therapeutic effect of nitrate on dextran sulfate sodium induced acute experimental colitis in mice

Abstract

Objective To investigate the effect of nitrate on acute experimental colitis in mice.Methods A total of 40 BALB/c mice were evenly divided into model group and treatment group.Model group were fed with 4％ dextran sulfate sodium (DSS) solution and treatment group were given 4％ DSS solution and nitrate (1.5 g/L) for seven days.The disease activity index (DAI) of mice was scored.The colon tissue of mice was taken for hematoxylin-eosin staining and myeloperoxidase (MPO)immunohistochemical staining observation.The MPO and activity of nitric oxide in colon tissue were measured by MPO and nitric oxide detecting kit.The data were analyzed by t test.Results At the 6th day and 7th day,the difference of DAI between treatment group and model group was statistically significant (t=5.12 and 6.72,P=0.012 and 0.008).At the 7th day,the tissue score of model group (2.5±0.5) was higher than that of treatment group (1.9±0.4) and the difference was statistically significant (t=3.82,P＜ 0.01).Compared with model group,the histopathological injury of colon tissue in treatment group mice significantly reduced and neutrophil infiltration also decreased.At the 7th day,the concentration of MPO,NO2-and NO3-of model group was (2.8±0.6) U/g,(10.4±4.3) mmol/g and (100.3±50.1) mmol/g respectively,treatment group was (1.5±0.3) U/g,(17.5±7.0) mmol/g and (190.7 ±85.3) mmol/g respectively.The differences were statistically significant (t=11.23,3.81 and 4.50,all P＜0.01).Conclusion Nitrate can reduce DSS-induced acute experimental colitis in mice. Key words: Colitis; Nitrates; Nitric oxide; Peroxidase; Mice, inbrecl BALB C