Effects of Curcumin on the treatment of oral lichen planus symptoms: a systematic review and meta-analysis study

Abstract

Background and objectives Oral lichen planus (OLP) is a relatively common chronic T-cell–mediated disease that can cause significant pain, particularly in its erosive or ulcerative forms. This study aimed to examine the therapeutic impact of curcumin on symptoms of OLP. Materials and methods This meta-analysis was performed according to the PRISMA guidelines. All related English documents indexed in electronic databases (including PubMed, Web of Science, Scopus, Embase, Wiley, Cochrane, and ProQuest databases [updated to August 15, 2023]) were retrieved. Data were double-extracted into a predefined worksheet, and quality analysis was performed using the Joanna Briggs Institute (JBI) scale. We carried out meta-analyses, and the random effects model was used to estimate the differences in erythema, lesion size, and pain between the curcumin control groups. Results The search identified 289 studies, of which 10 were found to meet the inclusion criteria. The overall findings of the meta-analysis revealed that curcumin did not have a significant effect on erythema of OLP (standardized mean difference [SMD] = -0.14; 95% CI, -0.68 to 0.40; P = 0.61; I2 = 57.50%), lesion size of OLP (SMD = -0.15; 95% CI, -0.45 to 0.15; P = 0.33; I2 = 28.42%), and pain of OLP (SMD = -0.38; 95% CI, -0.97 to 0.22; P = 0.22; I2 = 86.60%). However, subgroup analysis based on treatment duration indicated that 2-week treatment duration was significantly associated with a reduction in OLP pain (n = 3; SMD = -1.21; 95% CI, -2.19 to -0.23; P = 0.01). Conclusions Curcumin had no significant effect on erythema, lesion size, and pain of OLP compared to the control groups. However, subgroup analysis revealed that curcumin was more effective in reducing pain in non-randomized trials and in trials with a treatment duration of 2 weeks.