Avaliação da ecotoxicidade do fármaco maleato de enalapril em Oreochromis niloticus

Abstract

Enalapril maleate (EM) is a pharmaceutical drug used to treat arterial hypertension, acting as a vasodilator through inhibition of the renin-angiotensin-aldosterone system. EM is widely consumed in Brazil, where hypertension is a prevalent disease that requires continuous pharmacological treatment. Pharmaceuticals such as EM are classified as emerging contaminants (Ecs)4chemical compounds that can pose risks to the environment and human health but are not routinely monitored or regulated. In recent decades, this field of study has gained prominence, and various groups of emerging contaminants, including pharmaceuticals, have been detected in water bodies in numerous studies. This study aimed to assess the ecotoxicity of EM using its analytical standard (99.7% purity), with juvenile Oreochromis niloticus (Nile tilapia)4.a species commonly used as a bioindicator due to its ecological and economic relevance. Toxicity was assessed using genetic biomarkers (comet assay and piscine micronucleus test), biochemical biomarkers (analysis of acetylcholinesterase, catalase, glutathione S-transferase, and lipid peroxidation levels), and a somatic biomarker (Fulton’s condition factor). A 21-day subchronic waterborne bioassay was conducted with 70 juvenile fish, divided into five experimental groups to evaluate the toxicological effects of EM at environmentally relevant concentrations of 100, 500, 1000, and 2000 μg/L. Genetic assays revealed DNA damage that increased in a concentration-dependent manner, both in the comet assay and in the analysis of nuclear morphological alterations. The biochemical biomarkers indicated oxidative stress and neurotoxicity. Lastly, the somatic biomarker showed a decline in the overall health condition of the organisms after exposure. These findings suggest that, although the damage observed was relatively low, EM has the potential to cause long-term harm to aquatic organisms, especially considering its continuous release into the environment.