Network Pharmacology and Experimental Validation to Elucidate the Pharmacological Mechanisms of Luteolin Against Chondrocyte Senescence

Background: Luteolin, a flavonoid found in various medicinal plants, has shown promising antioxidant, anti-inflammatory, and anti-aging properties. The cartilaginous endplate (CEP) represents a crucial constituent of the intervertebral disc (IVD), assuming a pivotal responsibility in upholding both the structural and functional stability of the IVD. Objective: Exploring the precise mechanism underlying the protective effects of luteolin against senescence and degeneration of endplate chondrocytes (EPCs). Methods: Relevant targets associated with luteolin and aging were obtained from publicly available databases. To ascertain cellular functions and signaling pathways, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were employed. Core genes were identified through the construction of a protein-protein interaction (PPI) network. Molecular docking (MD) was utilized to assess the binding affinity of luteolin to these core genes. Finally, the impact of luteolin on the senescence and degeneration of EPCs was evaluated in an in vitro cellular senescence model induced by tert-butyl hydroperoxide (TBHP). Results: There are 145 overlapping targets between luteolin and senescence. Analysis using GO revealed that these targets primarily participate in cellular response to oxidative stress and reactive oxygen species. KEGG analysis demonstrated that these markers mainly associate with signaling pathways such as p53 and PI3K-Akt. MD simulations exhibited luteolin’s binding affinity to P53, Cyclin-dependent kinase (CDK)2, and CDK4. Cell cycle, cell proliferation, and β- galactosidase assays confirmed that luteolin mitigated senescence in SW1353 cells. Western blot assays exhibited that luteolin significantly suppressed the expression of Matrix Metallopeptidase (MMP) 13, P53, and P21, while concurrently promoting CDK2, CDK4, and Collagen Type II Alpha 1 (COL2A1) expression. Conclusion: In summary, luteolin demonstrated beneficial properties against aging and degeneration in EPCs, offering novel insights to mitigate the progression of intervertebral disc degeneration (IVDD).