Abstract

Background

Ulcerative colitis (UC) is a chronic inflammatory condition of the colon characterized by episodes of disease activity and symptom‐free remission.There is paucity of evidence regarding the efficacy and safety of complementary or alternative medicines for the management of UC. Curcumin, an anti‐inflammatory agent, has been used in many chronic inflammatory conditions such as rheumatoid arthritis, esophagitis and post‐surgical inflammation. The efficacy of this agent for maintenance of remission in patients with UC has not been systematically evaluated.

Objectives

The primary objective was to systematically review the efficacy and safety of curcumin for maintenance of remission in UC.

Search methods

A computer‐assisted literature search of MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, and the Cochrane Inflammatory Bowel Disease Specialized Trial Register was performed on July 11, 2012 to identify relevant publications. Proceedings from major gastroenterology meetings and references from published articles were also searched to identify additional studies.

Selection criteria

Randomized placebo‐controlled trials (RCT) of curcumin for maintenance of remission in UC were included. Studies included patients (of any age) who were in remission at the time of recruitment. Co‐interventions were allowed.

Data collection and analysis

Two authors independently extracted data and assessed the methodological quality of the included studies using the Cochrane risk of bias tool. Data were analyzed using Review Manager (RevMan 5.1). We calculated the relative risk (RR) and 95% confidence interval (95% CI) for each dichotomous outcome. For continuous outcomes we calculated the mean difference (MD) and 95% CI.

Main results

Only one trial (89 patients) fulfilled the inclusion criteria. This trial randomized 45 patients to curcumin and 44 patients to placebo. All patients received treatment with sulfasalazine or mesalamine. The study was rated as low risk of bias. Curcumin was administered orally in a dose of 2 g/day for six months. Fewer patients relapsed in the curcumin group than the placebo group at six months. Four per cent of patients in the curcumin group relapsed at six months compared to 18% of patients in the placebo group (RR 0.24, 95% CI 0.05 to 1.09; P = 0.06). There was no statistically significant difference in relapse rates at 12 months. Twenty‐two per cent of curcumin patients relapsed at 12 months compared to 32% of placebo patients (RR 0.70, 95% CI 0.35 to 1.40; P = 0.31). A total of nine adverse events were reported in seven patients. These adverse events included sensation of abdominal bulging, nausea, transient hypertension, and transient increase in the number of stools. The authors did not report which treatment group the patients who experienced adverse events belonged to. The clinical activity index (CAI) at six months was significantly lower in the curcumin group compared to the placebo group (1.0 2.0 versus 2.2 2.3; MD ‐1.20, 95% CI ‐2.14 to ‐0.26). The endoscopic index (EI) at six months was significantly lower in the curcumin group than in the placebo group (0.8 0.6 versus 1.6 1.6; MD ‐0.80, 95% CI ‐1.33 to ‐0.27).

Authors' conclusions

Curcumin may be a safe and effective therapy for maintenance of remission in quiescent UC when given as adjunctive therapy along with mesalamine or sulfasalazine. However, further research in the form of a large scale methodologically rigorous randomized controlled trial is needed to confirm any possible benefit of curcumin in quiescent UC.

Author(s)

Sushil K Garg, Vineet Ahuja, Mari Jeeva Sankar, Atul Kumar, Alan C Moss

Abstract

Plain language summary

Curcumin for maintenance of remission in ulcerative colitis

Curcumin is a natural anti‐inflammatory agent that is often used in many chronic inflammatory conditions including rheumatoid arthritis, esophagitis and post‐surgical inflammation. The purpose of this systematic review was to examine the effectiveness and safety of curcumin therapy for the maintenance of remission in patients with ulcerative colitis (UC), a chronic inflammatory condition of the colon. Currently available agents for the management of this condition have been reported to result side effects, particularly when used for prolonged periods. This review includes one randomized trial with a total of 89 participants. All patients received treatment with sulfasalazine or mesalamine (drugs containing 5‐aminosalicylic acid). Fewer patients in the curcumin group relapsed at six months compared to patients who received placebo (e.g. fake drug). However, this result was not statistically significant. Patients in the curcumin group had significantly lower disease activity index and endoscopic index scores at six months than patients in the placebo group. No serious side effects were reported. A total of nine mild side effects were reported in seven patients. These side effects included a sensation of abdominal bulging, nausea, a brief increase in blood pressure, and a brief increase in the number of stools. The results of this systematic review suggest that curcumin may be a safe and effective therapy for maintenance of remission in ulcerative colitis when given as additional therapy with mesalamine or sulfasalazine. Further research is needed to confirm any possible benefit of curcumin for maintenance therapy in ulcerative colitis.

Author(s)

Sushil K Garg, Vineet Ahuja, Mari Jeeva Sankar, Atul Kumar, Alan C Moss

Reviewer's Conclusions

Authors' conclusions 

Implications for practice 

Curcumin may be an effective and safe therapy in maintenance of remission in ulcerative colitis when given with standard treatments (sulfasalazine or mesalamine) over a period of six months. However, its use for this indication should occur in the context of a well‐conducted randomised clinical trial. Curcumin is not currently approved by regulatory bodies in the U.S. or Europe for clinical use for the treatment of ulcerative colitis. This review was unable to answer the question of its efficacy compared to other interventions in maintaining remission, or the optimal dose to be used, or the optimal duration of therapy for this purpose.

Implications for research 

Well designed RCTs are required to determine the efficacy and safety of curcumin at varying doses in patients with mild to moderately active ulcerative colitis and in patients with quiescent disease, either as an alternative or adjunctive therapy to mesalamine. These trials should include validated clinical and endoscopic end‐points, and be appropriately sized to detect clinically meaningful effect sizes. Based on the relapse rates in the placebo group at 6 months, we estimated that at least 706 patients per group need to be enrolled to detect a 30% relative reduction in the proportion of patients with relapse following curcumin therapy (assuming alpha error of 0.05 and power of 80%). The topical effects of curcumin on the colonic mucosa should also be measured in vitro, and compared to mesalamine in down‐regulating local inflammation in models of colitis.

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