Collectively, our study has demonstrated, for the first time, the antioxidant, anti-inflammatory and immunomodulatory effects of dietary OLE in CIA model, which were accompanied by an important attenuation of RA biomarkers (MMP-3), pro-inflammatory cytokines (IL-6, IL-1β, IL-17, IFN-γ, TNF-α), and inhibition of COX-2, mPGES-1 and iNOS overexpression. This evidence concerns the gene PTGS2 and rheumatoid arthritis.