Chaigui Bitong decoction inhibits rheumatoid arthritis fibroblast-like synoviocyte injury through regulating the ferroptosis signaling pathway via Nrf2/HO-1/GPX4 axis

The present work analyzed the mechanisms of Chaigui Bitong Decoction (CBD) in rheumatoid arthritis fibroblast-like synoviocytes (RA-FLSs), with a particular focus on the effects of its disassembled prescriptions, Qufeng Chushi (QC) and Tongluo Zhitong (TZ). Mass spectrum data and effective components of CBD were obtained using UPLC-Q-TOF-MS. The targets of CBD were screened by performing network pharmacology analysis. The therapeutic efficacy of CBD and its disassembled prescriptions for RA as well as the underlying mechanisms were analyzed using TNF-α-induced MH7A cells. Cell proliferation, the expressions of ferroptosis marker and reactive oxygen species (ROS) and the level of Fe 2+ levels were measured. Additionally, the expression of proteins associated with inflammatory factor IL-6, and Nrf2/HO-1/GXP4 signaling pathways was detected. A total of 102 compounds in CBD were screened. Visualized network of CBD-ingredients-targets-pathways-RA revealed that the ferroptosis pathway and Nrf2 were the core targets of CBD. Notably, CBD, QC, and TZ markedly inhibited cell proliferation and the expressions of IL-6 to suppress the inflammatory response in RA patients. Furthermore, CBD, QC, and TZ elevated the levels of Fe 2+ , promoted ROS accumulation, and effectively inhibited the protein expressions of HO-1, Nrf2, and GPX4, thereby activating the cellular ferroptosis pathway. Notably, such effects were partially reversed after the treatment of ferroptosis inhibitor (Fer-1) and Nrf2 agonist TBHQ. Our study confirmed that CBD and its disassembled prescriptions could inhibit abnormal proliferation and inflammatory factors in MH7A cells induced by TNF-α through modulating the Nrf2/HO-1/GXP4 signaling pathway, ferroptosis, and redox homeostasis.