Network pharmacology, molecular dynamics simulation, and experiments uncover icariin's role in ferroptosis during postmenopausal osteoporosis

Icariin (ICA) shows therapeutic potential for postmenopausal osteoporosis (PMO), yet its mechanism in regulating osteoblast ferroptosis remains unclear. We combined network pharmacology, molecular docking, molecular dynamics simulation, and in vitro validation to elucidate ICA-mediated anti-ferroptotic effects in PMO. Potential ICA targets were obtained from PubChem, the Comparative Toxicogenomics Database, SwissTargetPrediction, and the Similarity Ensemble Approach, while PMO-associated genes were identified through GeneCards, OMIM, DrugBank, and the Therapeutic Target Database. Ferroptosis-related genes were extracted from FerrDb. Intersecting targets were used to construct drug–target and protein–protein interaction (PPI) networks, and key nodes were identified by topological analysis. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were used to perform functional enrichment. Molecular docking assessed ICA affinity toward candidate proteins, and molecular dynamics simulations evaluated complex stability. Reactive oxygen species (ROS), apoptosis, and the expression of markers linked to ferroptosis, antioxidants, and osteogenesis were measured using osteoblasts in vitro using quantitative RT-PCR and western blotting. Eight key targets were identified through PPI network analysis. GO and KEGG enrichment analyses highlighted pathways associated with redox regulation and ferroptosis. Docking studies revealed the strongest binding affinity between ICA and Nrf2 (Nuclear Factor Erythroid 2–Related Factor 2), further confirmed by stable interactions in molecular dynamics simulations. Experimentally, ICA promoted osteoblast proliferation, reduced intracellular ROS levels and apoptosis, and upregulated antioxidant, osteogenic, and ferroptosis-related proteins, including Nrf2, heme oxygenase-1 (HO-1), glutathione peroxidase-4 (GPX4), solute carrier family 7 member 11 (SLC7A11), alkaline phosphatase (ALP), and runt-related transcription factor-2 (RUNX2), while suppressing caspase-3 activation. ICA activates the Nrf2/HO-1 pathway to suppress ferroptosis and oxidative stress, reduce apoptosis, and promote osteogenic activity, thereby alleviating PMO-related osteoblast dysfunction. These findings provide mechanistic support for ICA as a multi-target candidate for PMO management.