Assessment of Photo Apoptotic and Genotoxicity of Nalidixic Acid on the Mouse Fibroblast Cell Line Under Ambient Environmental Intensity of UV-B Irradiation

<b>Objectives:</b> Nalidixic acid has been used as a potent antibiotic drug in the biomedical sciences. In this study, we assessed photochemical properties of nalidixic acid as well as its effect for photocytotoxicity, apoptosis, and genotoxicity on the mouse fibroblast (L929) cell line over the course of 24 h under the ambient UVB intensity. <b>Methods:</b> Reactive oxygen species such as singlet oxygen (¹O₂), superoxide anion radical (O₂ ^•-), and hydroxyl radical (^•OH) were measured by photochemical test and photocytotoxicity, apoptosis, and genotoxicity on the mouse fibroblast (L929) cell line were determined by various methods. <b>Results:</b> Furthermore, in UV-B irritated L929 cells, nalidixic acid decreased GSH and raised LPO levels compared to dark control cells. Nalidixic acid caused concentration-dependent toxicological effects (<i>P</i> < 0.05) in L929 cells when exposed to ambient UVB intensity (1.4 mW/cm²). DNA fragmentation and caspase-3 activity were observed to be significantly (<i>P</i> < 0.05) activated in L929 cells under co-exposure of UV-B and nalidixic acid. <b>Conclusion:</b> Our results thus confirm that when exposed to UVB rays, nalidixic acid exhibits both phototoxic and photo-genotoxic effects.