Curcumin in the treatment of oral submucous fibrosis: a systematic review and meta-analysis of randomized controlled trials

The objective was to evaluate the efficacy of curcumin in improving mouth opening (MO), burning sensation (BS), and tongue protrusion (TP) symptoms in patients with oral submucous fibrosis (OSF). An electronic search up to November 2022 was conducted in the PubMed, Web of Science, Embase, EBSCO, ProQuest, and Cochrane Library databases to identify studies using curcumin in the treatment of OSF with comparison to control groups (drugs previously proven to be effective for OSF treatment) or placebo. Only randomized controlled trials (RCTs) were considered. RevMan 5.3 software was used for the meta -analysis. Thirteen RCTs met the eligibility criteria and were included in the analysis. The results showed no significant improvement in MO (in millimetres) for curcumin when compared to control at 1 month (P = 0.91), 2 months (P = 0.54), 3 months (P = 0.56), or 6 months (P = 0.17) of treatment. There was no significant difference in BS (assessed using a visual analogue scale) between curcumin and control after 1 month (P = 0.05), 2 months (P = 0.64), 3 months (P = 0.13), or 6 months (P = 0.56) of treatment. Compared with the control groups, treatment with curcumin for 1 month (P = 0.32), 2 months (P = 0.07), and 3 months (P = 0.14) did not significantly improve the TP (in millimetres) of patients. The administration of curcumin, whether topically applied or taken orally, did not confer statistically significant improvements in MO, BS, or TP in comparison to the control treatments, among patients with OSF. The results of this meta -analysis showed that compared to placebo, the application of curcumin for 6 months markedly alleviated BS (P < 0.001). Curcumin treatment in OSF reaches a clinically effective range, but more bioavailability-centred outcomes should be reported. Robust multicentre RCTs are warranted to elucidate the efficacy of curcumin in improving specific outcomes like MO, BS, and TP in patients with this condition. Defining the therapeutic role of this natural compound may provide an effective botanical alternative for managing OSF.