Oxidative Stress Biomarkers as Indicators of Pharmaceutical Toxicity in Fish: A Review

Human pharmaceutical residues are increasingly recognized as environmental contaminants that pose significant risks to aquatic ecosystems. This review focuses on the oxidative stress induced in fish by these pharmaceutical residues. Pharmaceuticals, including antidepressants, anti-inflammatories, and other widely used medications, enter aquatic ecosystems through multiple pathways, most notably through their use in human and veterinary medicine, the subsequent metabolic excretion via urine and feces, and wastewater treatment plant effluents. These substances, often only partially removed during water treatment, persist in the environment and pose potential risks to aquatic organisms, impacting water quality and ecosystem health. Upon exposure, fish exhibit oxidative stress responses characterized by the overproduction of reactive oxygen species (ROS) and subsequent damage to cellular components such as lipids, proteins, DNA, and RNA. This review summarizes current research on the oxidative stress (OS) responses of various fish species to environmental concentrations of pharmaceuticals. It explores the mechanisms underlying OS, identifies the specific pharmaceuticals involved, and discusses these responses' physiological and ecological implications.