Genistein from Thai Fermented Soybean (Thua-nao) Attenuates Osteoarthritis Pathogenesis via Dual Inhibition of NF-κB and MAPK Signaling: Evidence from Ex Vivo, Computational, and In Vitro Models.

Aglycone isoflavones derived from fermented soybeans demonstrate antioxidant, anticancer, antiobesity, and anti-inflammatory properties, with evidence suggesting protective effects against cartilage deterioration. However, precise mechanisms in chondrocytes remain unclear. This study screened extracts from Thai fermented soybean (Thua-nao) for chondroprotective effects using an ex vivo porcine cartilage explant model. Dichloromethane (DCM) and ethyl acetate (EA) extracts enriched in daidzein and genistein, primary aglycone isoflavones, effectively attenuated the IL-1β/OSM-induced extracellular matrix depletion from explants. Computational analysis predicted genistein to inhibit NF-κB and MAPK signaling effectively, with high gastrointestinal absorption. The in vitro experiments using primary chondrocytes showed that genistein upregulated ACAN while downregulating aggrecanase genes, thereby affecting key chondrogenic markers. Additionally, genistein inhibited IL-1β-mediated MAPK and NF-κB activation and suppressed matrix metalloproteinases (MMP) -1, -3, and -13 expression. Altogether, these findings demonstrate the chondroprotective properties of Thai fermented soybean extract and strengthen the potential of genistein as a promising therapeutic candidate for osteoarthritis.