Enhancing Ferroptosis in Lung Adenocarcinoma Cells via the Synergistic Action of Nonthermal Biocompatible Plasma and a Bioactive Phenolic Compound

Para-coumaric acid (p-CA) is a phenolic compound that has antioxidant, anti-inflammatory, and anticancer properties which make it potential for cancer treatment. However, its effectiveness has been limited by poor solubility, rapid metabolism, and poor absorptivity. Nonthermal biocompatible pressure plasma (NBP) has gained attention as a cancer treatment due to its ability to generate reactive oxygen and nitrogen species (RONS), inducing oxidative stress that damages cancer cells. This study aimed to investigate the combined effect of NBP and p-CA on the induction of ferroptosis in lung adenocarcinoma via the GPX4, xCT, and NRF2 pathways. H460 and A549 lung adenocarcinoma cells as well as normal lung cells (MRC5) were treated with p-CA, NBP, and their combination. Cell movement, intracellular RONS levels, and lipid peroxidation, along with apoptosis and ferroptosis-related gene expression, were evaluated by co-treatment. Co-treatment also significantly elevated NO₂^-, NO₃^-, and H₂O₂ levels and reduced cancer cell (H460, A549) viability (26, 31%) without affecting normal cells MRC5 (7%). Elevated MDA levels and changed expression of ferroptotic proteins indicated mitochondrial dysfunction, oxidative damage, lipid peroxidation, and DNA damage, which resulted in the induction of ferroptosis. These findings reveal a novel ferroptosis mechanism, emphasizing co-treatment for delivering bioavailable natural anticancer drugs.