Isofraxidin inhibits interleukin-1β induced inflammatory response in human osteoarthritis chondrocytes

Osteoarthritis (OA) is the most prevalent disease of knee especially in the aged people. Isofraxidin (IF) is a coumarin compound refined from traditional Chinese medicines with potential anti-inflammatory ability. This study aimed to evaluate protective anti-inflammatory effects of IF in human OA chondrocytes. The chondrocytes were isolated from OA patients and pretreated with IF before treatment with IL-1 beta. The results showed that IF blocked IL-1 beta-stimulated production of NO and PGE2. In addition, IF inhibited the expression of COX-2, iNOs, MMP-1, MMP-3, MMP-13, ADAMTS-4 and ADAMTS-5, and increased the levels of aggrecan and collagen-II. Mechanistically, IF suppressed IL-1 beta-induced I kappa B-alpha degradation and NF-kappa B activation. In conclusion, our results demonstrate that IF inhibits inflammation in OA via the regulation of NF-kappa B signaling, and suggest that IF may be a potential therapeutic agent for OA.