Reduced fluoxetine-induced cyto- and genotoxicity in yellowtail tetra fish Astyanax altiparanae (Characiformes: Acestrorhamphidae) after treatment through a constructed wetlands system

Fluoxetine hydrochloride (FLX) is an antidepressant classified as a selective serotonin reuptake inhibitor. It is commonly found in aquatic environments due to human excretion and improper disposal practices. The presence of FLX raises concerns, as it is linked to behavioral, physiological, and genetic alterations in non-target aquatic organisms. This study investigated the toxic effects of FLX on Astyanax altiparanae, focusing on blood and gill responses, and evaluated the efficiency of a vertical flow constructed wetland (VFCW) as a sustainable treatment solution. Five groups were established: a control, three exposed to increasing FLX concentrations (0.01, 0.1, and 1 mg L-1), and one exposed to 1 mg L-1 of treated effluent by VFCW. After 96 h, the specimens exposed to FLX showed a significant increase in the frequency of micronuclei (MN), cellular morphological changes (CMC), DNA damage, and histopathological lesions in the gills. In contrast, our results indicated that more than 99% of the FLX was removed in the VFCW, with a display of around 89% of cells without DNA damage, a significant reduction in MN, CMC, and histopathological lesions. These results demonstrate the system’s efficiency in removing FLX and mitigating its adverse effects on aquatic organisms.