Abietic acid attenuates IL-1β-induced inflammation in human osteoarthritis chondrocytes

Abietic acid has been reported to have anti-inflammatory activity. However, whether abietic acid has anti-inflammatory effects against osteoarthritis (OA) remains unclear. The present study aimed to measure the anti-inflammatory effects of abietic acid on OA in vitro. Human osteoarthritis chondrocytes were pretreated with abietic acid 1 h before IL-1 beta treatment. The results showed that treatment of abietic acid significantly inhibited IL-1 beta-induced TNF-alpha, NO, PGE2 production, and COX-2 expression. Abietic acid also concentration-dependently suppressed MMP1, MMP3, and MMP13 production induced by IL-1 beta. Moreover, the increased phosphorylation levels of NF-kappa B p65 and I kappa B alpha were inhibited by the treatment of abietic acid. We also found that the expression of PPAR-gamma was increased by abietic acid. The inhibition of abietic acid on TNF-alpha, NO, and PGE2 production were reversed by GW9662, the inhibitor of PPAR-gamma. In conclusion, the study elucidated abietic acid suppressed IL-1 beta-induced inflammation in human osteoarthritis chondrocytes by activating PPAR-gamma.