Scientific Abstract
Proposal No. IBD-0191
Principal Investigator: Mutsuhiro Ikuma, M.D., Ph.D. (Former Principal Investigator: Yukio Koide, M.D., Ph.D.)
Applicant Organization: Hamamatsu University (Japan)
Project Title: A randomized clinical trial of curcumin in the therapy of ulcerative colitis
Period of Award: November 1, 2006 - April 30, 2009
Curcumin is a natural constituent of curry spice containing turmeric. Curcumin has a variety of pharmacological effects. We have demonstrated that curcumin is able to prevent and improve murine experimental colitis by suppressing NF-κB activation and CD4+ T cell infiltration in colonic mucosa. Furthermore, we demonstrated the efficacy of curcumin in combination therapy with sulfasalazine (SASP) or 5-amino salicylic acid (5-ASA) in prevention of exacerbation of ulcerative colitis (UC) in a double-blind controlled trial. Therefore, the aim of this clinical trial is to investigate the efficacy of curcumin without additional drugs in maintaining remission of UC in a randomized, double-blind trial. Ten centers in Japan will enroll a total of 200 patients. This number is calculated based on the results from our previous study (recurrence rate of curcumin group was 4-5%, compared to the rate of placebo group 15-20%) by using an unmatched case-control study (assuming curcumin group patients number versus control number ration is 1:1). When the desired power of our study (1-β) was set at 80% with a significance level of 0.05 in a two-sided test, at least 67 patients and same number of controls were required. Therefore, our sample size is considered sufficient to study the efficacy of curcumin. Randomization will be performed by the clinical pharmacist. Patients will be treated with either 4 g of curcumin or SASP/5-ASA for six months. Before and after treatment (one to three months after treatment and six months after treatment), the patients will be subjected to endoscopy combined with histological examination in biopsy specimens such as pathological grading and cytokine measurements by immuno-histochemical study and by real-time RT-PCR. Furthermore, the patients’ overall evaluation of symptoms is assessed according to the Mayo score.