AbstractOsteoarthritis is a common chronic degenerative disease, of which the essence is the degenerative changes of bone and joint cartilage, involving damage in multiple structures such as bone, synovium and joints. In the mechanism of arthritis inflammation is closely related, and therefore the exploration to inhibit inflammatory mediators is crucial for the clinical prevention and treatment of osteoarthritis. Inotodiol is a lanostane triterpenoid isolated from Inonotus obliquus, which had been extensively reported to be an anti-inflammatory agent, but its effect on arthritis remains unknown. In this study, we firstly demonstrated that inotodiol significantly reduced IL-1β-induced chondrocyte injury and inhibited the release of inflammatory factors. At the same time, experiments in vivo showed that inotodiol could effectively improve the symptoms of joint injury in mice and reduce the area of cartilage destruction, indicating that inotodiol may be a potential therapeutic drug for osteoarthritis.