Integrating Network Pharmacology, Microbiomics, and Metabolomics to Uncover the Therapeutic Effect of Liubao Tea on Osteoarthritis
Background: Osteoarthritis (OA) is a debilitating joint disorder with no effective disease-modifying drugs. Liubao tea, a traditional Chinese dark tea, possesses various bioactivities, including anti-inflammatory and gut microbiota-regulating effects. However, its potential therapeutic role and mechanism of action in OA remain unexplored.Methods: Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used to analyze the chemical components of Liubao tea. Network pharmacology was employed to identify the active components and their potential targets in OA treatment. A destabilization of the medial meniscus (DMM)-induced mouse OA model was established and treated with low/high-dose Liubao tea extract. Micro-CT, histological staining (H&amp;E, Safranin O-Fast Green), and ELISA were performed to evaluate joint structure, cartilage damage, and inflammatory cytokine levels. 16S rRNA sequencing, fecal microbiota transplantation (FMT), and untargeted serum metabolomics were conducted to explore gut microbiota and metabolic changes. Additionally, Brequinar, a de novo pyrimidine synthesis inhibitor, was used to verify the role of pyrimidine metabolism.Results: UPLC-MS/MS and network pharmacology analyses identified 1,989 metabolites in Liubao tea, including 273 bioactive components (e.g., flavonoids, lignans) that targeted 602 OA-related genes. Liubao tea treatment significantly ameliorated DMM-induced OA progression, as evidenced by improved subchondral bone microarchitecture (increased BV/TV, Tb.N, Tb.Th; decreased Tb.Sp), reduced cartilage erosion (lowered modified Mankin and OARSI scores), and suppressed systemic inflammation (decreased IL-6, IL-1beta, TNF-alpha levels). Liubao tea remodeled gut microbiota homeostasis (increased -diversity and altered bacterial taxa), and FMT from Liubao tea-treated mice recapitulated its anti-OA effects. Metabolomic analysis revealed that Liubao tea significantly downregulated the pyrimidine metabolism pathway, and Brequinar treatment mimicked its therapeutic benefits, confirming the role of pyrimidine metabolism suppression in OA alleviation.Conclusion: Liubao tea attenuates OA progression by modulating gut microbiota composition and inhibiting the pyrimidine metabolism pathway, highlighting its potential as a novel natural therapeutic strategy for osteoarthritis.