F. Soler Rodríguez

Effects of deltamethrin on biometric parameters and liver biomarkers in common carp (Cyprinus carpio L.)

The present study is aimed to evaluate the effect of sublethal exposure to the pyrethroid pesticide deltamethrin, according to biometric parameters and important liver biomarkers in the common carp (Cyprinus carpio). Fish were exposed for 4, 15 and 30 days to deltamethrin mixed to the aquaria water at the concentrations of 0.08, 0.4 and 0.8μg/L. The exposure did not affect fish biometric parameters. Glutathione-S-transferase (GST) activity in liver (hepatopancreas) increased in fish exposed to the high concentration of pesticide only after 30 days when compared to controls. A significant increase of malondialdehyde (MDA) content (79.4% and 90.2% of control) was remarked after 15 and 30 days of exposure to the highest concentration of pesticide. Catalase activities (CAT) went up after 4 days of was to the concentration of 0.4μg/L and 0.8μg/L and at 15 days of exposure to 0.4μg/L. The most significant change of glutathione reductase (GR) activity was recorded at the fourth day, when GR activity was significantly increased after exposure to the concentrations of 0.4μg/L and 0.8μg/L of deltamethrin.

Biomarkers of oxidative status associated with metal pollution in the blood of the white stork (Ciconia ciconia) in Spain

The aim of this study was to determine the impact of specific environmental contaminants on the activities of antioxidant enzymes in terrestrial, free-living birds. To investigate this, several biomarkers and the levels of lead, mercury, and arsenic were determined in blood of white stork (Ciconia ciconia) nestlings from two different colonies located in the west of Spain that were exposed to different environmental conditions and human activities. Different biomarker and contaminant patterns were observed between the two colonies, suggesting different levels of environmental contamination. In comparison to nestlings from a natural reference area, the levels of the three hazardous elements Pb, As, and Hg were significantly higher in the colony nearby a landfill. Analysis of antioxidant biomarkers revealed significantly higher levels of glutathione and glutathione S-transferase activity in birds from the colony close to the landfill site than were found in those from the “control” area. In contrast, the levels of malondialdehyde did not significantly differ between the two sampling sites. In addition, a positive correlation between glutathione and both Hg and As has been observed. Taken together, exposure to the three hazardous elements is reflected by enhanced activity of glutathione S-transferases, and elevated levels of glutathione and malondialdehyde. White storks can therefore be considered as a suitable model species for environmental monitoring programs.

Effects of subchronic exposure to carbofuran on antioxidant defence system and malondialdehyde levels in common carp (Cyprinus carpio L.)

The present study focused on the assessment of oxidative stress induction by pesticides such as carbamates which are widely used as insecticides and nematicides and contaminate aquatic ecosystems on certain biomarkers in liver of common carp (Cyprinus carpio L.). Biomarkers selected for stress monitoring were malondialdehyde (MDA), an index of lipid peroxidation, and antioxidant defence system enzymes, mainly catalase (CAT), glutathione reductase (GR), and glutathione-S-transferase (GST) activities in liver of fish exposed to 0, 10, 50, or 100 µg L−1 of carbofuran for 4, 15, or 30 days. Oxidative stress was found in liver of common carp exposed to carbofuran which was manifested by a decrease in CAT and GR activities after 4 and 30 days of exposure. An adaptive response was probably produced since at day 15 no modifications in the CAT activity and increased GR activity were observed. In addition, a decrease in MDA content with the highest concentration of carbofuran used was found after 30 days of exposure. However, no significant changes were found in GST activity showing a varied response. The results concerning oxidative and antioxidant profiles indicate that subchronic exposure to the insecticide carbofuran is capable of inducing oxidative stress in fish.