Biochemical and Cellular Biomarkers in Brown Trout (Salmo trutta f. fario) in Response to the Antidepressants Citalopram and Venlafaxine

Abstract

Background: During the last decades, a worldwide increase in the number of cases of depression accompanied by rising prescription rates of antidepressants was recorded. In Germany, the two most prescribed antidepressants are the selective serotonin reuptake inhibitor (SSRI) citalopram and the serotonin and noradrenalin reuptake inhibitor (SNRI) venlafaxine, taking about 30 % of the market share. Both antidepressants are found frequently in surface waters and have the potential of adversely affecting aquatic organisms. Most studies dealing with antidepressants address apical endpoints and behaviour, however, only few studies investigate biochemical biomarkers and histopathological alterations. We conducted citalopram and venlafaxine exposure experiments with brown trout eggs in the eyed ova stage for five months, as well as with juvenile brown trout for four weeks. Exposure concentrations ranged from environmentally relevant 1 µg/L up to 1 mg/L. In this study, we investigated the effects of the antidepressants on b-esterase activity (neurotoxicity), stress protein level (proteotoxicity) and superoxide dismutase activity (oxidative stress). Additionally, we assessed the health status of the liver by means of histopathological analyses.Results: We were able to show that both antidepressants did neither induce proteotoxic nor neurotoxic effects in brown trout. But for the antidepressant venlafaxine, the biochemical biomarker for oxidative stress (superoxide dismutase activity) was significantly increased in larvae exposed to at least 10 µg/L venlafaxine at 7°C. With regard to liver histopathology, fish exposed to higher citalopram concentrations were in a worse health condition than control fish irrespective of their life stage. Also the energy storage of fish exposed to 1 mg/L citalopram was reduced. Conclusion: Thus, we here report citalopram-dependent histopathological alterations in brown trout liver, and the induction of oxidative stress by venlafaxine.

Enantioselective Ecotoxicity of Venlafaxine in Aquatic Organisms: Daphnia and Zebrafish

“…In addition, some studies showed that venlafaxine can lead to the formation of reactive oxygen species (ROS) causing cellular damage (Ahmadian et al, 2016; Zafir et al, 2009). Nevertheless, only a few studies have reported biochemical changes in fish (Ziegler et al, 2020).…”