Panduratin A Induces Caspase-Dependent Apoptosis and G1-Associated Cell-Cycle Arrest and Enhances TNF-α-Associated Cytotoxicity in NSCLC Cells

Background: Non-small-cell lung cancer (NSCLC) is a major cause of cancer-related mortality. Current therapies are limited by drug resistance and adverse effects, highlighting the need for new strategies. Panduratin A (PA), a chalcone from Boesenbergia rotunda, has reported anticancer activity. This study investigated the effects of PA in NSCLC cells and whether PA enhances tumor necrosis factor alpha (TNF-α)-associated cell death. Methods: Human NSCLC cell lines A549 and H1299 were treated with PA alone or in combination with TNF-α. Cytotoxicity and apoptosis were assessed using cell-viability assays, cell-number analysis, and flow cytometry. Western blotting was used to evaluate caspase-3 activation and PARP-1 cleavage. Cell-cycle distribution was analyzed to determine the impact of PA on cell-cycle progression. Results: PA reduced cell number and induced cell death in both A549 and H1299 cells, and co-treatment with TNF-α increased apoptosis compared with single-agent treatment. PA increased the G1-phase fraction and, in a concentration-dependent manner, reduced expression of thymidine kinase and cyclin A2, consistent with a G1-associated arrest phenotype. Combination treatment also increased the sub-G1 population. Conclusions: PA promotes apoptosis in NSCLC cells and enhances TNF-α-associated apoptotic cell death in vitro, accompanied by a G1-associated cell-cycle phenotype. These findings provide an in vitro framework for studying natural compounds as modulators of TNF-α-driven apoptosis and support further mechanistic validation in more disease-relevant models.