geraniol modulation of oxidative stress caused by polyethylene terephthalate nanoplastics in hek-293 cell line

Background: the environmental degradation of plastics into micro- and nanoplastics (mnps) poses a significant threat to human health. polyethylene terephthalate nanoplastics (pet-nps) are of particular concern due to their ability to induce intracellular oxidative stress, a key mechanism of nanoplastic toxicity. geraniol (3,7-dimethylocta-2,6-dien-1-ol), a natural monoterpenoid, has demonstrated potent antioxidant and cytoprotective properties in various models of chemical-induced toxicity.objectives: this study aimed to investigate the oxidative stress induced by pet-nps in human embryonic kidney (hek-293) cells and to evaluate the potential protective effects of geraniol against this toxicity.methods: hek-293 cells were divided into four groups: control, pet-nps (ic₅₀ = 420.7 µg/ml), geraniol (ic₅₀ = 697.7 µg/ml), and a co-treatment group (pet-nps + 100 µg/ml geraniol). following 48 hours of exposure, cytotoxicity was assessed via the mtt and lactate dehydrogenase (ldh) assays. oxidative stress markers, including superoxide dismutase (sod), catalase (cat) activities, and total antioxidant capacity (tac), were measured. the experimental design and reporting adhere to the principles for in vitro toxicology studies.results: pet-np exposure significantly increased ldh release (by ~67%) and depleted antioxidant defenses, reducing sod, cat, and tac levels compared to the control (p<0.0001). co-treatment with geraniol significantly attenuated this damage, reducing ldh release by 23% and restoring tac by 200% relative to the pet-np-only group. geraniol co-treatment also induced a protective shift in the ic₅₀ of pet-nps from 267.9 µg/ml to 437.6 µg/ml at 72 hours, indicating enhanced cellular resistance.conclusion: geraniol effectively mitigates pet-np-induced cytotoxicity in hek-293 cells by preserving membrane integrity and augmenting the cellular antioxidant defense system. these findings position geraniol as a promising therapeutic candidate for countering the adverse effects of nanoplastic exposure.