Ethyl acetate extract of Tinospora crispa alleviates osteoarthritis by suppressing ERK1/2-mediated MMP13 transcription and cartilage degradation

Osteoarthritis (OA) is a chronic degenerative joint disorder characterized by inflammation, oxidative stress, and cartilage destruction, resulting in pain, locomotor dysfunction, and substantial health burdens in both humans and animals; however, safe and effective long-term therapeutic strategies remain limited. Tinospora crispa (TC) is a traditional ethnomedicine with anti-inflammatory and antioxidant properties, yet its therapeutic effects and underlying mechanisms in OA remain unclear. LC‒MS analysis revealed 11 main compounds in the TC extract. The network pharmacology results revealed that MMP9, MMP13, TNF, and MAPK signaling pathway components were key candidate targets of TC for the treatment of osteoarthritis. This study demonstrated that TC extract alleviated OA in mice subjected to destabilization of the medial meniscus (DMM) surgery by reducing pain-related sensitivity, inhibiting osteophyte formation and preventing cartilage matrix degradation. In vitro experiments demonstrated that TC extract inhibited chondrocyte apoptosis and reactive oxygen species (ROS) production, downregulated the expression of inflammatory cytokines and genes involved in extracellular matrix degradation, and suppressed MMP13 promoter activity. RNA-seq analysis indicated that the TC extract suppressed ERK1/2 pathway activity, which was subsequently confirmed by western blotting. Syringic acid (SA), a major active compound of TC extract, was also shown to inhibit ROS production, downregulate the expression of inflammatory cytokines and extracellular matrix degradation-related genes, and suppress MMP13 promoter activity in vitro. Finally, western blotting and dual-luciferase assays revealed that TC extract and SA inhibited MMP13 transcription by suppressing ERK1/2 signaling, revealing the mechanism by which they alleviate OA.