Integrated cartilage metabolomics and proteomics analysis reveals the therapeutic effect of Wenjing Tongluo Decoction on Knee osteoarthritis rats

Knee osteoarthritis (KOA)is an age-related degenerative whole-joint disease characterized by poor outcomes. Wenjing Tongluo Decoction (WJTLD), a Chinese herbal remedy, has demonstrated favorable clinical effects on KOA. However, the precise mechanisms therein remain poorly defined. In this study, we employed the method of anterior cruciate ligament transection (ACLT) method to establish a rat model of KOA. Following 8 weeks of oral administration of WJTLD, the morphology of knee joint cartilage was evaluated using Safranin-O/Fast green staining, H&E staining, and micro-CT imaging. Utilizing GC-MS based untargeted metabolomics and nano-LC-QE-MS based proteomics, we identified altered metabolites and proteins associated with knee cartilage in different rat groups, which were further validated through western blotting and real-time PCR. Our findings indicate that WJTLD alleviates damage to knee joint cartilage and inhibits cartilage degradation. Proteomics data revealed that the altered proteins in OA and WJTLD treated group were related to the biological process including amoebiasis, platelet activation, ECM-receptor interaction, protein digestion and absorption, and ribosome function. Western blotting results confirmed that the expression levels of MMP8 and LDHA were significantly upregulated in the KOA group but were rescued by WJTLD treatment. According to untargeted metabolomics, the intensities of lactic acid, isoleucine, lysine, glutamate, myo-inositol, adenosine, and β-alanine were significantly elevated in the KOA group, however, these metabolites experienced a dramatic following WJTLD treatment. These results suggest that WJTLD exerts a therapeutic effect on KOA by suppressing inflammation and cartilage degradation, as well as regulating multiple pathways related to ECM degradation, amino acid metabolism, and energy metabolism, including glycolysis.