Formononetin inhibits IL-1β-induced inflammation in human chondrocytes and slows the progression of osteoarthritis in rat model via the regulation of PTEN/AKT/NF-κB pathway

Osteoarthritis (OA) is a common degenerative disease characterized by cartilage degradation and inflammation. This study aimed to investigate the anti-inflammatory properties of formononetin, an isoflavone extracted from astragalus membranaceus, on OA.Human OA chondrocytes were pretreated in vitro with formononetin and subsequently stimulated with IL-1β. The production of inflammatory mediators, cytokines and the synthesis of catabolic factors were evaluated by ELISA and Western blot analysis. In addition, a rat model of OA was established and treated with formononetin.Formononetin attenuated the overproduction of inflammatory mediators and cytokines, suppressed the expression of cyclooxygenase-2 and inducible nitric oxide synthase, and inhibited the synthesis of catabolic factors such as MMPs and thrombospondin motifs 5. Furthermore, formononetin exerted protective effects in a rat model of OA. Mechanistically, we found that formononetin inhibited IL-1β induced activation of nuclear factor kappa B and AKT by activating the phosphatase and tensin homolog.Formononetin could be used as a potential agent for OA treatment.