Curcumin-QingDai Combination for Patients With Active Ulcerative Colitis: A Randomized, Double-Blinded, Placebo-Controlled Trial

Background & Aims: We evaluated the efficacy of herbal combination of curcumin-QingDai (CurQD) in active ulcerative colitis (UC). Methods: Part I was an open-label trial of CurQD in patients with active UC, defined by a Simple Clinical Colitis Activity Index score of 5 or higher and a Mayo endoscopic subscore of 2 or higher. Part II was a placebo-controlled trial conducted in Israel and Greece, randomizing active UC patients at a 2:1 ratio to enteric-coated CurQD 3 g/d or placebo for 8 weeks. The co-primary outcome was clinical response (reduction in the Simple Clinical Colitis Activity Index of ≥3 points) and an objective response (Mayo endoscopic subscore improvement of ≥1 or a 50% fecal calprotectin reduction). Responding patients continued either maintenance curcumin or placebo alone for an additional 8 weeks. Aryl-hydrocarbon receptor activation was assessed by cytochrome P450 1A1 (CYP1A1) mucosal expression. Results: In part I, 7 of 10 patients responded and 3 of 10 achieved clinical remission. Of 42 patients in part II, the week 8 co-primary outcome was achieved in 43% and 8% of CurQD and placebo patients, respectively (P =.033). Clinical response was observed in 85.7% vs 30.7% (P <.001), clinical remission in 14 of 28 (50%) vs 1 of 13 (8%; P =.01), a 50% calprotectin reduction in 46.4% vs 15.4% (P =.08), and endoscopic improvement in 75% vs 20% (P =.036) in the CurQD and placebo groups, respectively. Adverse events were comparable between groups. By week 16, curcumin-maintained clinical response, clinical remission, and clinical biomarker response rates were 93%, 80%, and 40%, respectively. CurQD uniquely up-regulated mucosal CYP1A1 expression, which was not observed among patients receiving placebo, mesalamine, or biologics. Conclusions: In this placebo-controlled trial, CurQD was effective for inducing response and remission in active UC patients. The aryl-hydrocarbon receptor pathway may merit further study as a potential UC treatment target. ClinicalTrials.gov ID: NCT03720002.