Original scientific paper
https://doi.org/10.2478/aiht-2020-71-3473
Oxidative and apoptotic effects of fluoxetine and its metabolite norfluoxetine in Daphnia magna
Sevgi Başalan Över
; Adıyaman University Institute of Natural and Applied Sciences, Department of Biology, Adıyaman, Turkey
Celal Güven
; Niğde Ömer Halisdemir University Faculty of Medicine, Department of Biophysics, Niğde, Turkey
Eylem Taskin
; Niğde Ömer Halisdemir University Faculty of Medicine, Department of Physiology, Niğde, Turkey
Yusuf Sevgiler
orcid.org/0000-0002-4373-2389
; Adıyaman University Faculty of Science and Letters, Department of Biology, Adıyaman, Turkey
Abstract
The aim of this study was to investigate the oxidative and apoptotic potential of fluoxetine, a widely used antidepressant in Turkey and the world, and of its metabolite norfluoxetine on a model non-target organism, Daphnia magna to see how exposure to this group of antidepressants (specific serotonin reuptake inhibitors) could affect the aquatic environment in which they end up. Juvenile D. magna specimens were chronically exposed to fluoxetine and norfluoxetine alone and in combination at concentrations found in the aquatic environment (0.091 and 0.011 μg/L, respectively) and to their 10-fold environmental concentrations for 21 days. Another group of 17-day-old animals were subacutely exposed to 100-fold environmental concentrations for four days. After exposure, we measured their glutathione peroxidase (GPx) and cholinesterase (ChE) activities, thiobarbituric acid-reactive substances (TBARS), and total protein content spectrophotometrically, while mitochondrial membrane potential (MMP) was analysed by fluorescence staining, and cytochrome c and ERK1/2 protein content by Western blotting. This is the first-time cytochrome c and ERK1/2 were determined at the protein level in D. magna. We also measured their carapace length, width, and caudal spine length microscopically. At environmental concentrations fluoxetine and norfluoxetine caused an increase in ChE activity and brood production. They also caused a decrease in juvenile carapace length, width, and caudal spine length and depolarized the mitochondrial membrane. At 10-fold environmental concentrations, GPx activity, lipid peroxidation levels, cytochrome c, and ERK1/2 protein levels rose. The most pronounced effect was observed in D. magna exposed to norfluoxetine. Norfluoxetine also decreased brood production. Similar effects were observed with subacute exposure to 100-fold environmental concentrations. However, total protein content decreased. All this confirms that fluoxetine and norfluoxetine have oxidative and apoptotic potential in D. magna. Daphnia spp. have a great potential to give us precious insight into the mechanisms of environmental toxicants, but there is still a long way to go before they are clarified in these organisms.
Keywords
cholinesterase; cytochrome c; ERK1/2; GPx; lipid peroxidation; mitochondrial membrane potential; oxidative stress; TBARS
Hrčak ID:
243871
URI
Publication date:
22.9.2020.
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