Abstract: AIM: To observe clinical efficacy and mechanism of mesalamine oral combined with enema for mildly to moderately distal ulcerative colitis. METHODS: 40 patients with mildly to moderately distal active ulcerative colitis were randomly divided into two groups:trial group (20 cases,mesalamine oral combined with enema)and control group (20 cases, mesalamine oral only),were both treated for 4 weeks. The changes of clinical efficacy and disease activity index(Sutherland DAI)were evaluated before and after the treatment.The expression of MiR-155 in intestinal mucosa was detected by Realtime-PCR.RESULTS: After the treatment for 4 weeks,the trial group total efficiency was better than the control group (P<0.05), the descent range of DAI significantly was higher in trial group than that in control group(P<0.05), the descent range of the expression of MiR-155 in intestinal mucosa significantly was higher in trial group than that in control group(P<0.01). CONCLUSION: The clinical efficacy in the near future of mesalamine oral combined with enema for distal mildly to moderately active ulcerative colitis was superior to that of mesalamine oral only, the intestinal mucosa ulcer heal rapidly and the DAI cut down, by decreasing expression of MiR-155.

Key words: mesalamine, ulcerative colitis, clinical efficacy, MiR-155