Morin Exhibits Anti-Inflammatory Effects on IL-1β-Stimulated Human Osteoarthritis Chondrocytes by Activating the Nrf2 Signaling Pathway.

Osteoarthritis (OA) is a multifactorial disease that is associated with inflammation in joints. The purpose of the present study was to investigate the anti-inflammatory activity and mechanism of morin on human osteoarthritis chondrocytes stimulated by IL-1β.The levels of NO and PGE2 were measured by the Griess method and ELISA. The levels of MMP1, MMP3, and MMP13 were also measured by ELISA.The results revealed that IL-1β significantly increased the production of NO, PGE2, MMP1, MMP3, and MMP13. Additionally, the increases were significantly attenuated by treatment with morin. Furthermore, IL-1β-induced NF-κB activation was suppressed by morin. In addition, the expression of Nrf2 and HO-1 were increased by morin and knockdown of Nrf2 could prevent the anti-inflammatory effects of morin.In conclusion, this study suggested that morin attenuated IL-1β-induced inflammation by activating the Nrf2 signaling pathway.