Mice deficient in cytosolic PLA2?? (cPLA2??) have been reported to reduce eicosanoid production in the presence of collagen-induced arthritis, indicating that cPLA2 plays a critical role in the pathogenesis of RA (8).ROS have been implicated in inflammatory responses through the activation of transcription factors NF-??B and activator protein 1 (AP-1) (9, 10) and signaling pathways such as MAPKs,