Acute exposure to environmentally relevant concentrations of phenytoin induces oxidative stress and organ-specific histopathological damage in adult zebrafish (Danio rerio)

Phenytoin (PHEN), a widely prescribed antiepileptic drug, is increasingly detected in surface waters, yet its toxic effects on fish remain poorly characterized. This study evaluated the acute impact of environmentally relevant PHEN concentrations on adult zebrafish (Danio rerio). Fish (۲۲۳ ± ۴۰ mg; ۳.۴ ± ۰.۳ cm) were exposed for ۹۶ h to ۲۵ ng/L, ۲۸۲ ng/L, and ۱۵۰۰ ng/L PHEN, alongside a control. PHEN exposure significantly increased lipid peroxidation (malondialdehyde, MDA), inhibited key antioxidant enzymes—catalase (CAT) and superoxide dismutase (SOD)—and elevated glutathione (GSH) levels in gut tissue (p < ۰.۰۵). Histopathological analyses revealed dose-dependent lesions, including hyperemia, branchitis, and lamellar degeneration in the gills; hyperemia and hepatic steatosis in the liver; and hyperemia, hemorrhage, and epithelial necrosis in the kidneys. Overall, short-term PHEN exposure impaired antioxidant defenses and induced oxidative and structural damage across multiple organs in a concentration-dependent manner, indicating potential ecological risks associated with pharmaceutical contamination in aquatic environments.

کلیدواژه ها:

Phenytoin ، Antiepileptic drug ، Oxidative stress ، Histopathology ، Zebrafish