Curcumin use in ulcerative colitis: is it ready for prime time? A systematic review and meta-analysis of clinical trials

BACKGROUND: Curcumin, an active ingredient of the Indian herb turmeric (Curcuma longa), has shown promising anti-inflammatory properties. Studies of its potential benefits in treating patients with ulcerative colitis (UC) are limited. We performed a systematic review and meta-analysis of human randomized placebo controlled trials to evaluate the efficacy of adjunctive therapy with curcumin in treating patients with UC. METHODS: We conducted a search of several databases (from January 2000 to September 2018). A random-effects model was used for analysis. We assessed heterogeneity between study-specific estimates using the Cochran Q statistical test, 95% prediction interval (PI) and I(2) statistics. The outcomes assessed were the pooled odds of clinical response and remission as well as the endoscopic response. RESULTS: A total of 7 studies with 380 patients (curcumin n=188; placebo n=190) were included in the final analysis. The pooled odds ratio for clinical remission with curcumin use was 2.9 (95%CI 1.5-5.5, I(2)=45, P=0.002), clinical response was 2.6 (95%CI 1.5-4.5, I(2)=74%, P=0.001), and endoscopic response/remission was 2.3 (95%CI 1.2-4.6, I(2)=35.5%, P=0.01). CONCLUSIONS: Based on our study, combined mesalamine and curcumin therapy was associated with roughly threefold better odds of a clinical response compared to placebo, with minimal side effects. This response was statistically significant, albeit with heterogeneity, probably due to the different severity scoring indices, curcumin dosages and routes of drug delivery used.