CURCUMIN-QINGDAI COMBINATION FOR PATIENTS WITH ACTIVE ULCERATIVE COLITIS: A RANDOMIZED DOUBLE-BLINDED PLACEBO-CONTROLLED CLINICAL TRIAL

Abstract

Abstract BACKGROUND The herbal extracts Curcumin and QingDai were previously shown to be effective in mild-moderate and in moderate-severe ulcerative colitis (UC), respectively. We evaluated the efficacy and safety of a combination of curcumin-QingDai (CurQD) in patients with active UC. METHODS This was a two parts trial. Part 1 was an open label study of 4 weeks CurQD in patients with active UC, defined by a Simple Clinical Colitis Activity Index (SCCAI) score ≥5 and a modified Mayo endoscopic sub-score≥2. Part 2 was a placebo-controlled trial conducted in two centers in Israel and Greece, that randomized active UC patients at a 2:1 ratio to either enteric-coated CurQD 3gr/day or an identical placebo for eight weeks. The co-primary outcome at week 8 was clinical response (reduction in SCCAI of ≥3 points) and an objective evidence of response (Mayo endoscopic subscore improvement of ≥1 or 50% calprotectin reduction from baseline). Responding patients continued either Curcumin or placebo alone for additional 8 weeks as maintenance treatment. Expression of Cyp1A1 in rectal mucosa was assessed as a measure of aryl-hydrocarbon receptor (AhR) pathway activation. Curcumin purity, and indigo and indirubin content in CurQD were confirmed by LC-MS/MS. RESULTS 59 patients were enrolled in the two study parts. In efficacy analysis of part 1, 7/10 responded including 3/10 who achieved clinical remission. For part 2, 95 patients were screened and 42 were included and randomized. The co-primary outcome was achieved in 43% and 8% of CurQD and placebo patients, respectively (p=0.033). Clinical response was observed in 85.7% versus 30.7% (p<0.001), 50% calprotectin-reduction in 46.4% versus 15.4% (p=0.08) and endoscopic improvement in 75% versus 20% (p=0.036), in the CurQD and placebo groups, respectively. The overall rate of adverse events was comparable between the groups. Among week-8 responders to CurQD, additional 8 weeks of treatment with curcumin alone resulted in 93%, 80% and 40% with maintained clinical response, clinical remission and clinic-biomarker response, respectively, at week 16. CurQD treatment uniquely resulted in activation of the AhR pathway, as gauged by up-regulated expression of CYP1A1 in the rectal mucosa, which was not observed among patients receiving placebo, nor was it observed in patients responding to 5ASA or biologic drugs. CONCLUSION In this randomized controlled trial, combination CurQD was found to be effective for inducing remission in active UC patients. Induction of AhR may merit further study as a potential treatment target in active UC.