Herba Patriniae Component Linarin Induces Cell Cycle Arrest and Senescence in Non-Small-Cell Lung Cancer Associated with Cyclin A2 Downregulation

<b>Background</b>: Non-small-cell lung cancer (NSCLC) remains a major therapeutic challenge due to its high incidence and mortality. <i>Herba Patriniae</i> (HP), a traditional Chinese medicine, has long been used for respiratory disorders and exhibits anti-cancer potential. However, the therapeutic effects of HP on NSCLC and the underlying mechanisms have not been fully elucidated. <b>Methods</b>: Network pharmacology was applied to identify the core active components of HP and their potential targets in NSCLC. The anti-cancer effects of the core HP component Linarin on the malignant phenotypes of NSCLC cells were characterized using Tumor Protein P53 (p53) wild-type A549 and p53-null H1299 cell lines with Cell Counting Kit-8 (CCK-8), EdU fluorescence staining, colony formation, apoptosis analysis, cell cycle analysis, and senescence-associated β-galactosidase (SA-β-gal) staining, together with molecular docking and Western blotting analyses. <b>Results</b>: Network pharmacology analysis identified Linarin as the core active component of HP and screened out six hub targets, including Cyclin Dependent Kinase 1/4 (CDK1/4), Cyclin A2/B1 (CCNA2/B1), and Checkpoint Kinase 1/2 (CHEK1/2), which were found to be mainly enriched in cell cycle and senescence pathways. In vitro assays showed that Linarin dose-dependently (0-200 μM) inhibited NSCLC cell proliferation, induced G0/G1 phase arrest, and promoted cellular senescence and apoptosis in both cell lines, irrespective of p53 status. Molecular docking confirmed strong binding affinities between Linarin and the hub targets, and Western blotting confirmed that Linarin downregulated CCNA2/B1 and CHEK1. <b>Conclusions</b>: This study demonstrates that Linarin, the core active component of HP, exerts potent anti-NSCLC effects by inducing G0/G1 arrest, senescence, and apoptosis. These effects are associated with the downregulation of key cell cycle regulators, including CCNA2/B1 and CHEK1. Together, these findings highlight the potential of Linarin as a promising therapeutic option for NSCLC.