The polyphenolic extract (PE) from extra virgin olive oil (EVOO) has been shown to possess important anti-inflammatory and joint protective properties in murine models of rheumatoid arthritis (RA). This study was designed to evaluate the effects of PE on IL-1β-activated human synovial fibroblasts SW982 cell line. PE from EVOO treatment inhibited IL-1β-induced matrix metalloproteases (P<0·001), TNF-α and IL-6 production (P<0·001). Similarly, IL-1β-induced cyclo-oxygenase-2 and microsomal PGE synthase-1 up-regulations were down-regulated by PE (P<0·001). Moreover, IL-1β-induced mitogen-activated protein kinase (MAPK) phosphorylation and NF-κB activation were ameliorated by PE (P<0·001). These results suggest that PE from EVOO reduces the production of proinflammatory mediators in human synovial fibroblasts; particularly, these protective effects could be related to the inhibition of MAPK and NF-κB signalling pathways. Taken together, PE from EVOO probably could provide an attractive complement in management of diseases associated with over-activation of synovial fibroblasts, such as RA.
Keywords: CIA collagen-induced arthritis; COX cyclo-oxygenase; DMSO dimethylsulfoxide; ERK extracellular signal-regulated kinase; EVOO extra virgin olive oil; HTy hydroxytyrosol; IκBα nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor; JNK c-Jun N-terminal kinase; MAPK mitogen-activated protein kinase; MMP matrix metalloproteinase; PE polyphenolic extract; RA rheumatoid arthritis; SF synovial fibroblast; SRB sulforhodamine B; mPGES-1 microsomal PGE synthase-1; α; Extra virgin olive oil; Olive oil; Polyphenols; Rheumatoid arthritis; Synovial fibroblasts.