Ecotoxicological significance of cytochrome P450 in fish encompassing xenobiotic detoxification and physiological regulation

Cytochrome P450 (CYP) enzymes are central to the biotransformation of xenobiotics and endogenous compounds in fish, linking environmental exposure to physiological responses. This review focuses on CYP1A, CYP1B1, and CYP1C1 isoforms, highlighting their inducibility by pollutants such as polycyclic aromatic hydrocarbons, organophosphates, and endocrine disruptors. Mechanistic regulation via nuclear receptors, including AhR, PXR, and PPARs, and tissue-specific expression in liver, gill, kidney, and brain are discussed. CYP activity, monitored through biomarkers like EROD, GST, and UGT, is species-specific and influenced by environmental factors such as temperature, season, and reproductive status. Although total CYP content in fish is lower than in mammals, inducibility is pronounced, often producing reactive intermediates that increase oxidative stress, impair immunity, and disrupt endocrine and metabolic functions. By integrating data across species, chemicals, and exposure scenarios, this review highlights CYP enzymes as sensitive biomarkers for aquatic environmental monitoring and provides insights for ecotoxicological assessment and regulatory strategies.