The effects of increased freshwater salinity in the biodisponibility of metals (Cr, Pb) and effects on antioxidant systems of Oreochromis niloticus

• Published in: Ecotoxicology and environmental safety Vol. 84; pp. 249 - 253
• Main Authors: Baysoy, E., Atli, G., Gürler, C.Ö., Dogan, Z., Eroglu, A., Kocalar, K., Canli, M.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01.10.2012; Elsevier
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Animals; anthropogenic activities; Antioxidant; antioxidant activity; antioxidants; Antioxidants - metabolism; Applied ecology; bioavailability; Biological and medical sciences; biomarkers; Biomarkers - metabolism; Cichlids - metabolism; Ecotoxicology, biological effects of pollution; Enzyme Activation - drug effects; exposure duration; Fresh Water - chemistry; Fresh water ecosystems; freshwater; freshwater fish; Fundamental and applied biological sciences. Psychology; General aspects; Glutathione - metabolism; glutathione peroxidase; Glutathione Peroxidase - metabolism; Glutathione Reductase - metabolism; glutathione transferase; Glutathione Transferase - metabolism; glutathione-disulfide reductase; GSH; liver; Liver - drug effects; Liver - enzymology; Metal; metals; Metals - toxicity; monitoring; Oreochromis niloticus; oxidative stress; Oxidative Stress - drug effects; pollution; Salinity; salt stress; Salts - toxicity; superoxide dismutase; Superoxide Dismutase - metabolism; Synecology; Oreochromis niloticus; Metal; Antioxidant; GSH; Salinity; Ecotoxicology; Toxicity; Fresh water; Environmental factor; Heavy metal; Freshwater environment; Vertebrata; Pisces; Chromium; Lead; Environment
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2012.07.017

Anthropogenic activities can increase the salinity of freshwaters and this may cause stress for fish and affect metal bioavailability. Oxidative stress biomarkers are of great interest due to their responses to environmental stressors which provide valuable data for biological monitoring of aquatic pollution. Thus, the individual and combined effects of salinity and metals (Cr, Pb) were investigated in the liver of freshwater fish Oreochromis niloticus in the present study. Fish were exposed to salinity (2 and 8ppt) alone and salinity+metal (1μg/mL Pb and Cr) combination exposures for 0, 1, 7 and 14 days and subsequently antioxidant enzymes (superoxide dismutase, SOD; glutathione peroxidase, GPX; glutathione reductase, GR and glutathione S-transferase, GST) activities and glutathione (GSH) levels in the liver were measured. Data showed that all the parameters varied in relation to metal species, exposure durations and salinity levels. Profound alterations on the measured parameters were detected at the lower salinity compared to the higher one. Salinity increase effectively stimulated the antioxidant parameters. The effects of salinity and metals on the measured parameters increased as the exposure duration prolonged. SOD was the most affected antioxidant parameter from both salinity and metals. Because metal and salinity stresses affect fish antioxidant system, this work suggests that the chemistry of freshwaters should be taken into account in natural monitoring for metal contamination in the field. ► Salinity increase in freshwater affects antioxidant system of fish O. niloticus. ► Metal and salinity exposure of fish cause stress that can lead to alteration in antioxidant reaction. ► Profound effects were found at lower salinity. ► Salinity of freshwater should be taken into account in measuring antioxidant system of freshwater fish in the field.