Quality of Evidence Supporting the Role of Supplement Curcumin for the Treatment of Ulcerative Colitis: An Overview of Systematic Reviews

OBJECTIVES: Curcumin is a potential complementary treatment for ulcerative colitis (UC). This overview systematically summarizes and evaluates the existing evidence of curcumin in the treatment of UC. METHODS: Two researchers searched seven databases for systematic reviews (SRs)/meta-analyses (MAs) which are about randomized controlled trials (RCTs) on curcumin for UC. Two researchers use the Assessment of Multiple Systematic Reviews 2 (AMSTAR-2), the Risk of Bias in Systematic Reviews (ROBIS) scale, the list of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system to assess the included SRs/MAs. RESULTS: Seven published SRs/MAs were included in our study. According to the results of the AMSTAR-2 assessment, all SRs/MAs are considered to be of very low quality. According to the ROBIS evaluation results, no SR/MA has been assessed as a low risk of bias. According to the results of the PRISMA checklist assessment, no SR/MA has been fully reported on the PRISMA checklist. According to GRADE, a total of 19 outcome indicators extracted from the included SRs/MAs were evaluated. The quality of evidence was 10 moderate, 6 low, and 3 very low. CONCLUSIONS: Curcumin may be an effective and safe complementary treatment for UC. However, further standard and comprehensive SRs/MAs and RCTs are needed to provide an evidence-based medical rationale for this.