Siweixizangmaoru Decoction Alleviates Rheumatoid Arthritis by Enhancing Pol β-Mediated Attenuation of DNA Damage and Suppression of cGAS/STING/NF-κB/NLRP3-Associated Pyroptosis

Objective: Siweixizangmaoru decoction (SXD), a classical Tibetan prescription documented in the medical text Four Medical Tantras, has shown therapeutic activity in experimental rheumatoid arthritis (RA). However, its candidate active constituents and underlying mechanisms remain unclear. Methods: In this study, serum-absorbed constituents following SXD administration were profiled using ultra-high-performance liquid chromatography coupled with quadrupole-Orbitrap high-resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS), and network pharmacology was employed to identify core targets and candidate active constituents of SXD against RA. Candidate active constituents were further screened using cell-based assays, and the selected constituents were quantified using HPLC fingerprint analysis. Both in vivo (CIA rat model) and in vitro (RAW264.7 pyroptosis model) systems were used to investigate the pharmacological effects and mechanisms of SXD. Results: A total of 11 absorbed constituents were identified in the serum of SXD-treated rats, and four preliminary candidate active constituents, including chebulagic acid, kaempferol, gentiopicroside, and berberine, were screened. The combined in vivo and in vitro results showed that SXD attenuated RA progression and reduced inflammatory cytokine levels in rat serum and cell culture supernatants. At the molecular level, SXD increased Pol β expression and reduced DNA damage markers, cytosolic dsDNA accumulation, and cGAS/STING-, NF-κB-, and NLRP3-associated signaling. Pol β knockdown partially reduced the effects of SXD. Conclusions: These findings support the partial involvement of Pol β-associated processes in the anti-arthritic effects of SXD.