Illuminating the therapeutic potential of Schisandrin a against rheumatoid arthritis by targeting ferroptosis: An integrated bioinformatics and experimental study

Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammation and hyperplasia of the synovial membrane. This study aimed to elucidate the anti-inflammatory mechanisms of Schisandrin A (SCHA), a bioactive component from Schisandra chinensis, on RA fibroblast-like synoviocytes (FLSs). Integrated bioinformatics analysis was performed on transcriptomic datasets from RA and normal FLSs as well as SCHA-treated RA FLSs. Enrichment analysis revealed that differentially expressed genes between groups were significantly enriched in the ferroptosis pathway, suggesting SCHA may exert anti-inflammatory effects by inhibiting ferroptosis. Protein-protein interaction network analysis identified Txnrd1, lpcat3 and slc7a11 as key hub genes with pivotal roles in mediating SCHA's effects, and molecular docking and dynamics simulations demonstrated that SCHA directly binds to these proteins with favorable binding affinities through hydrogen bonds and hydrophobic contacts, with stable complex formation confirmed over 100-ns molecular dynamics trajectories. In lipopolysaccharide (LPS)-induced inflamed RA FLSs, SCHA significantly decreased pro-inflammatory cytokines IL-6, TNF-α and IL-1β at both protein and mRNA levels, restored antioxidant enzymes GSH-Px and SOD levels, and reduced lipid peroxidation product MDA, Fe2+ and ROS levels in a dose-dependent manner Transmission electron microscopy confirmed SCHA's dose-dependent protective effects against ferroptosis-induced mitochondrial damage. Our study demonstrates inhibition of ferroptosis via targeting TXNRD1, LPCAT3 and SLC7A11 mediates the anti-inflammatory effects of SCHA on RA FLSs. These findings reveal a novel mechanism for SCHA's therapeutic potential against RA by modulating ferroptosis.