Curcumin and Polyherbal Formulations in Rheumatoid Arthritis: A Systematic Review of Efficacy, Safety

Abstract

This systematic review evaluates the efficacy, safety, and evidence gaps of herbal formulations, particularly curcumin and polyherbal compounds, in the management of rheumatoid arthritis (RA). The evidence base was dominated by curcumin trials, which demonstrated significant improvements in DAS28, ESR, CRP, VAS pain, and ACR20 response rates, with no serious safety signals. The Yishen Tongbi decoction trial showed non-inferiority to methotrexate, achieving a CDAI response of 67.4% versus 57.1% at week 24. In contrast, the Qurs-e-Mafasil trial found no meaningful between-group difference in EULAR response over four weeks. Safety profiles were generally favorable, with mild gastrointestinal events reported occasionally. However, critical evidence gaps persist: no retrieved RA herbal trial reported gut microbiome outcomes, cost-utility data, patient-reported outcomes for fatigue or cognition, or synovial tissue drug concentrations. Evidence for herb-DMARD interactions was limited and heterogeneous, though animal models suggested that Andrographis paniculata extract reduced the Cmax and AUC of a coadministered anti-arthritic drug while still producing synergistic effects. The contribution of this review is the systematic synthesis of short-term efficacy and safety for curcumin and select polyherbal formulations, alongside the identification of major evidence gaps that must be addressed before these therapies can be integrated into RA treatment paradigms. Future research should prioritize long-term outcomes, mechanistic mediation, and economic evaluations.