Dioscin exhibits anti-inflammatory effects in IL-1β-stimulated human osteoarthritis chondrocytes by activating LXRα

Objective: Osteoarthritis (OA) is the most common joint disease that characterized by the degradation of articular cartilage. In this study, we aimed to investigate the anti-inflammatory activity of dioscin on IL-1 beta-stimulated human osteoarthritis chondrocytes. Methods: The production of PGE2 and NO was measured in this study. MMP1 and MMP3 were detected by ELISA. The expression of LXR alpha and NE-kappa B were tested by western blot analysis. Results: Treatment of dioscin suppressed the production of PGE2 and NO, as well as the expression of COX-2 and iNOS (their key regulatory genes). Dioscin also attenuated the secretion of MMP1 and MMP3. Furthermore, dioscin inhibited the phosphorylation of NF-kappa B p65 and I kappa B alpha induced by IL-1 beta. The degradation of I kappa B alpha induced by IL-1 beta was also suppressed by dioscin. Dioscin increased the expression of LXR alpha and pretreatment of GGPP, the LXR alpha inhibitor, blocked the anti-inflammatory effects of dioscin. Conclusions: In conclusion, this study indicated that dioscin-mediated anti-inflammatory effect may be involved in the activation of LXR alpha.