Anti-arthritic Effects of Oplopanax elatus in a Rat Model of Rheumatoid Arthritis (Adjuvant-induced Arthritis)

Abstract

The stems of Oplopanax elatus (OE) have long been used to treat inflammatory disorders in herbal medicine, and in the previous investigation, OE was found to possess anti-inflammatory activity in lipopolysaccharide-treated macrophages, RAW 264.7 cell. OE reduces inducible nitric oxide (NO) synthase-induced NO production, and interferes with mitogen-activated protein kinase activation pathways. In the present study, the pharmacological action of the water extract of OE was examined to establish anti-arthritic action, using a rat model of adjuvant-induced arthritis (AIA). The water extract of OE administered orally inhibited AIAinduced arthritis at (100 - 300) mg/kg/day. The paw edema was significantly decreased, in combination with reduced production of pro-inflammatory cytokines. The action mechanism includes an inhibition of MAPKs/ nuclear transcription factor-κB activation. These new findings strongly suggest that OE possesses anti-arthritic action, and may be used as a therapeutic agent in inflammation-related disorders, particularly in arthritic condition.