Effects of permethrin exposure on antioxidant enzymes and protein status in Mediterranean clams Ruditapes decussatus

The effects of permethrin (PER) on a panel of antoxidant enzymes; superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST) and indices of protein oxidation status (carbonylation and free thiols) were determined in digestive gland and gills of the clam Ruditapes decussatus. Animals were exposed to 100 ppb PER for 2 days. These enzyme activities increased significantly in digestive gland (p?<?0.05) after PER treatment and oxidative modification of proteins was detected in both gill and digestive gland extracts using redox proteomics. PER exposure significantly reduced the amount of protein free thiol groups in digestive gland rather than in gill, when compared to controls. Conversely, digestive gland showed significantly higher levels of carbonylated proteins than gill after PER exposure. Some proteins were successfully identified by mass spectrometry of tryptic peptides. Our data suggest that digestive gland of R. decussatus can be used as a model tissue for investigating environmental risk of PER contamination.     

Trace element contamination in the mine-affected stream sediments of Oued Rarai in north-western Tunisia: a river basin scale assessment

Environmental Geochemistry and Health - High-quality and accurate environmental investigations are essential for the evaluation of contamination and subsequent decision-making processes. A...     

Protective properties of filamentous blue–green alga Spirulina against the oxidative stress induced by cadmium in freshwater mussel Unio ravoisieri

ABSTRACT

Cadmium (Cd) is a toxic-heavy metal that induces a wide range of behavioural, biochemical and physiological effects in aquatic organisms. Oxidative damage has been proposed as a possible mechanism involved in cadmium toxicity. The current study was carried out to evaluate the antioxidant activity of Spirulina as feed additive (1?mg/L) against the toxicity of cadmium (Cd) 0.5?mg/L in freshwater mussel Unio ravoisieri. At the end of the exposed period of 4 days, digestive gland antioxidant status Superoxide dismutase, Catalase, Glutathione-S-transferase and damage markers such as Malondialdehyde and Protein carbonyl were determined. Associations between biomarkers were assessed by a multivariate analysis technique, principal component analysis (PCA). The results of this study revealed that digestive gland antioxidant status showed a significant decrease when mussels were exposed to Cd. Superoxide dismutase, Catalase and Glutathione-S-transferase activities in the Cd?+?SP group were significantly higher than the Cd group (p P?相似文献   

Titanium dioxide nanoparticles: synthesis,characterisations and aquatic ecotoxicity effects

Little information is available on the potential ecotoxicity of nanomaterials in the marine environment. In particular, the aquatic ecotoxicity impact of titanium dioxide (TiO₂) has been rarely reported. To carefully address this issue, we report on the synthesis of TiO₂ NPs using solvothermal process. The structure and morphology of the prepared TiO₂ nanoparticles were characterised using different techniques. To study the potential ecotoxicity effect of TiO₂, antioxidant system of mediterranean bivalves (Mytilus galloprovincialis) was used, measuring three oxidative biomarkers (ROS production, SOD activity and GSH/GSSG level). No considerable effect was found in the digestive glands of any of the groups treated with TiO₂ with concentration gradients ranging from 1 to 100?mg/L. Thus, the level of the superoxide anion, the activity of an antioxidant enzyme superoxide dismutase (SOD) and the GSH/GSSG ratio showed no significantly differences in digestive glands of all treated groups compared to the control. However, slight modifications were observed in the gills at high concentrations. These results demonstrated that TiO₂ appears to exert little toxicity on marine mussels after a short-term exposure at high concentration. However, before considering the use of this nanomaterial in various applications, further complementary studies are required in order to ensure the environmental safety of these NPs.     

The effects of anthracene on biochemical responses of Mediterranean mussels Mytilus galloprovincialis

Mediterranean mussels Mytilus galloprovincialis is among the most widely used bioindicators, and anthracene (AN) is one of the most commonly found hydrocarbons in the aquatic environment. M. galloprovincialis were exposed to nominal concentrations of 0.05, 0.15 and 0.4?μg/L AN. Chemical analysis using high-performance liquid chromatography revealed the uptake of AN in the whole soft body and digestive gland at different amounts. After a short exposure (2, 4 and 8 days), the results revealed that AN induced malondialdehyde (MDA), glutathione (GSH) and acetylcholinesterase (AChE) activity in digestive gland. Our findings demonstrated also that AN reduced the filtration rates in a concentration-dependent manner. Increase in lipid peroxidation (MDA content) in digestive gland (p?M. galloprovincialis, where digestive gland constitutes a valuable organ for investigating AN biotransformation and toxicity.     

Neurotoxicity and oxidative stress induced by permethrin in gills of the freshwater mussel Unio ravoisieri

Pyrethroids are contaminants found in the aquatic environment, and their toxicological effects on aquatic organisms have received extensive attention. However, the impact on freshwater bivalve of exposure to these chemicals is still largely unknown. Freshwater mussels Unio ravoisieri were exposed to two nominal permethrin (PM) concentrations C1?=?50?µg/L and C2?=?100?µg/L during 7 days. The measured concentrations of PM using gas chromatography (GC/ECD) in the treated aquariums were, respectively, 28.7–62.3?µg/L. Catalase (CAT), Glutathione-S-transferase (GST), and Acetylcholinesterase (AChE) activities, Glutatione (GSH) and Malondialdehyde (MDA) levels were determined in gills of U. ravoisieri. Significant increase in CAT activity by the lowest concentration and decrease by highest concentration were observed. Additionally, GST activity was increased in a concentration-dependent manner. However, statistically significant decrease in GSH levels (about 39%) was observed only at high concentration of this compound (100?µg/L). PM generated an increase in MDA levels reaching the highest value at the high concentration. AChE activity of mussel ranging from 51% inhibition at lowest concentration 50?µg/L to 89% inhibition at highest concentration 100?µg/L. The results indicated that oxidative stress and cell damage might be one of the main mechanisms of PM toxicity to freshwater mussels.     

Tolerance to agricultural pesticides of strains belonging to four genera of Rhizobiaceae

In order to determine their tolerance to pesticides, 122 strains of rhizobia isolated from different geographical regions, and belonging to the genera Rhizobium, Mesorhizobium, Sinorhizobium and Bradyrhizobium were tested against eight herbicides, four fungicides and five insecticides. Sensitivity to the pesticides was measured by using the filter paper disk method at four concentrations, 0.45, 4.5, 45 and 450 μg per disk. When the pesticides were used at 0.45 μg per disk, a concentration similar to that found when pesticides are applied under field conditions, no inhibition was observed. Strains growth was affected at concentrations of 45 and 450 μg pesticide per disk. These higher concentrations can be encountered when seeds are treated with pesticides. Pesticides tolerance level was correlated to pesticide function, i.e rhizobial strains were more tolerant to insecticides, followed by herbicides and then fungicides. Two fungicides, captan and mancozeb, inhibited the highest number of strains. Only one insecticide, carbaryl, affected the growth of some rhizobial strains. Strains isolated from the arctic (Mesorhizobium spp. and R. leguminosarum bv. viciae), a putative pesticides-free environment, were either less or equally affected by pesticides compared to strains isolated from agricultural regions.