The Effect Of Probiotics And Mesalazine On Ulcerative Colitis In Mice And Their Potential Mechanisms

Objective:To investigate the effect of probiotics-lactobacillus Combined with mesalazine on ulcerative colitis in mice to find its possible mechanism of treating uc.Methods:Experimental colitis was induced by drinking 2.5% dextran sulfate sodium (DSS) freely for 7 consecutive days. Seventy mice were randomly divided into seven groups as follows:normal control group, model control group, negative control group(normal saline,NS), mesalazine group, low-dose (106 CFU/ml),high-dose (108 CFU/ml) lactobacillus acidophilus group and lactobacillus acidophilus combined with mesalazine group. The normal group-mice were only fed with distilled water. Experimental group was induced by drink 2.5% dextran sulfate sodium (DSS, MW:36000-50000) freely for 7 consecutive days. Before two days, each experimental group of the mice was given normal saline(NS), mesalazine (30.25mg/ml), lactobacillus acidophilus (1.0×106CFU/ml), lactobacillus acidophilus (1.0x108CFU/ml), lactobacillus acidophilus (1.0x108CFU/ml) and mesalazine (30.25mg/ml) respectively. The model group was given empty needle to insert stomach.During the experiment, daily weight,stool trait and occult blood were recorded. After 8 days, the mice of each group were sacrificed. The distal colon were obtained respectively.Some colon specimens for maldehyde fixed, were embedded in paraffin and stained with hematoxylin-eosin (H&E), and the conditions of the mice were observed. Disease activity index(DAI) and histological injury scores were used to assess the efficacy of intervention groups; HSP70 and JNK expression in colonic mucosa were measured by immunohistochemistry(IHC).Results:1. probiotics could significantly reduce the DAI and colonic histological scores of experimental mice;2. The expression of JNK at protein level was decreased(P<0.05) in low-dose (106 CFU/ml),high-dose (108 CFU/ml) lactobacillus acidophilus group and lactobacillus acidophilus Combined with mesalazine group, compared with model control and negative control groups; The expression of HSP70 was increased, which was most evidenced in lactobacillus acidophilus Combined with mesalazine group.Conclusion:1. Both Lactobacillus acidophilus and mesalazine were effective on trearment of uc. Efficiency of Lactobacillus acidophilus is similar to that of mesalazine. lactobacillus acidophilus Combined with mesalazine is the best. 2. Lactobacillus had therapeutic effects on the acute UC mice. Its mechanism may be related to the inhibition of the activation of JNK and up-regulation of HSP70.