Fengshi Gutong Capsule Alleviates Osteoarthritis Pain in Association with the Suppression of STING/NF-ΚB Signaling and Modulation of Macrophage Polarization

Objective: This study aimed to evaluate the pharmacological effects of Fengshi Gutong Capsule (FSGT) on osteoarthritis (OA) and to explore the potential involvement of the STING/NF-κB signaling axis, using an integrated strategy combining network pharmacology with in vitro and in vivo experiments. Methods: In the present study, the active ingredients of the FSGT were identified by ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS), and their potential targets and pathways were predicted using network pharmacology. An osteoarthritis rat model was established via intra-articular injection of monoiodoacetate (MIA) to evaluate the therapeutic effects of FSGT. Serum levels of inflammatory cytokines were measured, and histopathological changes were assessed to evaluate the anti-inflammatory and analgesic efficacy. In addition, in vitro experiments, including cytotoxicity assay, flow cytometry, cytokine detection, and Western blotting, were performed to further validate the underlying mechanisms. Results: Chemical profiling of FSGT identified 125 constituents, while serum metabolomics revealed 10 differential metabolites. In vivo studies showed that FSGT ameliorated rat joint lesions and reduced serum inflammatory cytokine levels. To further investigate the underlying mechanisms, fuziline, identified as a representative blood-entering component of FSGT, was selected for in vitro experiments. In LPS-stimulated RAW264.7 macrophages, fuziline attenuated inflammatory responses, reduced the proportion of CD86-positive cells while increasing that of CD206-positive cells, and lowered cytokine levels. By integrating network pharmacology with experimental verification, the anti-inflammatory and analgesic actions of FSGT were found to be associated with modulation of the STING/NF-κB signaling axis, in which fuziline may act as a candidate bioactive constituent. Conclusions: In rats with OA, FSGT attenuated cartilage degradation, inflammatory responses, and pain symptoms. From a mechanistic perspective, these beneficial outcomes were associated with reduced activation of the STING/NF-κB signaling axis, and fuziline attenuated NF-κB-mediated cytokine release. These data suggest that FSGT could be developed as a potential treatment for OA.