Short-term exposure to pharmaceuticals negatively impacts marine flatfish species: Histological, biochemical and molecular clues for an integrated ecosystem risk assessment

The marine habitat and its biodiversity can be impacted by released pharmaceuticals. The short-term (7 days) effect of 3 commonly used drugs – warfarin, dexamethasone and imidazole – on Senegalese sole (Solea senegalensis) juveniles was investigated. Occurrence of hemorrhages, histopathological alterations, antioxidant status, activity of antioxidant enzymes and expression of genes involved in the xenobiotic response (pxr, abcb1 and cyp1a), were evaluated. The results showed a time and drug-dependent effect. Warfarin exposure induced hemorrhages, hepatocyte vacuolar degeneration, and altered the activity of glutathione peroxidase (GPx) and the expression of all the studied genes. Dexamethasone exposure increased liver glycogen content, altered antioxidant status, GPx and superoxide dismutase activities, as well as abcb1 and cyp1a expression. Imidazole induced hepatocyte vacuolar degeneration and ballooning, and altered the antioxidant status and expression of the tested genes. The present work anticipates a deeper impact of pharmaceuticals on the aquatic environment than previously reported, thus underlining the urgent need for an integrated risk assessment.

This research was partially funded by the Portuguese Foundation for Science and Technology (FCT, Portugal) through project UIDB/04326/2020 (CCMAR). I.F. acknowledges the Ramón y Cajal (Ref. RYC2018-025337-I, Spain) contract from the Plan Estatal de Investigación Científica y Técnica e Innovación 2017–2020 with funding from the Ministerio de Ciencia, Innovación y Universidades (MICIU, Spain) and the European Social Fund (“The European Social Fund invests in your future”).