Genotoxicity assessment of carp (Cyprinus carpioL.) fingerlings by tissue DNA damage and micronucleus test, after environmental exposure to fenitrothion

Oxidative DNA damage of lambda-cyhalothrin in model vertebrate organism

Pesticides, widely used for insect control in agriculture, public health, and veterinary medicine, are usually present as pollutants in aquatic environments. After contamination of water bodies, pesticides cause adverse effects on non-target organisms and long-term problems in the ecosystem. Lambda-cyhalothrin (LCH) is a chemical compound belonging to the family of synthetic pyrethroids (type II) and is an active ingredient in several insecticides. This study investigated the toxic effects (DNA damage) of LCH exposure on zebrafish for 24 and 72 h. After zebrafish (Danio rerio) were obtained commercially, acclimated, and adapted to laboratory conditions. They were randomly selected, transferred to the experimental aquariums (their average height is 2.51 ± 0.49 cm long, 10 L aquarium size of 10x20x35), and exposed to 0.1 mg/L LCH concentrations for 24 and 72 h. There was also a control and a solvent control group in the study, and whole body tissues of zebrafish were analyzed for 8-hydroxy-2-deoxyguanosine (8-OhdG) determination (ng/100 mg tissue), using an Agilent LC-MS/MS with electrospray ionization in positive ion mode. It was observed that the whole-body 8-OHdG tissue values were significantly increased in the group exposed to LCH for 72 h (9.82 ± 1.44) compared with the control group (6.60 ± 1.78, p = .004). These results suggest that LCH could lead to oxidative DNA damage by causing an increase in 8-OHdG activities in zebrafish, one of the aquatic ecosystem model organisms, indicating that it may also cause undesirable effects on other non-target species.

Environmental pollutant sodium omadine: toxic effects in zebra fish (Danio rerio)

In recent years one of the most striking results of over-population and consumption activities in the world is the rapid increase in environmental pollutants. Environmental pollutants, one of the harmful consequences of technological and modern life, threaten the health of people and other living organisms. In this study, we aimed to determine the effects of sodium omadine (NaOM) on superoxide dismutase enzyme (SOD) activity as an antioxidant and on 8-OHdG levels as oxidative DNA damage in zebrafish. Zebrafish, obtained from the aquarium fish producer, were stocked in experimental aquariums to ensure their adaptation period to the experimental conditions 15 days before the experiment. The fish were exposed to 1 ug/L and 5 ug/L concentrations of NaOM for 24, 72, and 96 h. SOD enzyme activity (U/100 mg tissue) and 8-OHdG (pg/100 mg tissue) were measured using commercial kits. The statistically significant differences in tissue SOD levels and data for DNA damage between the groups were determined as time and dose-dependent (p < 0.05). Biocidal products are environmental pollutants that cause changes in antioxidant enzyme activities, especially in non-target organisms. Marine pollution and the degradation of ecosystems directly affect people, and the results of the study offer awareness of health problems, environmental pollution, and marine pollution.

Toxic effects of fenitrothion on freshwater microcosms in Bangladesh

The organophosphate pesticide fenitrothion is widely used as an agricultural pesticide to control tiger bug in larval rearing for aquaculture. The objectives of the present study were to assess the effects of fenitrothion on certain structural (phytoplankton, zooplankton, macro-invertebrates and periphyton) and functional (organic matter decomposition) endpoints of freshwater microcosms. Fenitrothion 50 EC was applied in 12 microcosms (PVC tanks having 400 L of dechlorinated tap water) providing concentrations of 0, 25, 50 and 100 μg/L at a 4-day interval over a period of 4 weeks. Each of the experimental treatment was executed in three replicates. The results indicated the consistent significant effects for most of the species composition of zooplankton and macro-invertebrates. Univariate analysis showed a significant decrease in abundance (p < 0.05) of all identified insects (i.e. Notonecta sp., Gerris sp., Ranatra linearis and Chironomid larvae), when compared to control in all sampling days throughout the treatment period (no observed effect concentration; NOEC = < 25 μg/L). No consistent significant effects were observed for most of the phytoplankton taxa and organic matter decomposition and water quality variables (dissolved oxygen, free CO₂, pH, nitrate etc.). However, several taxa of different endpoints were found sensitive to even the lowest concentration of fenitrothion (25 μg/L). Further studies with acute and chronic conditions are recommended involving more local species exposed to < 25 μg/L of fenitrothion.

Assesment of hematotoxic, oxidative and genotoxic damage potentials of fipronil in rainbow trout Oncorhynchus mykiss, Walbaum

In this study, changes in the blood tissue of rainbow trout (Oncorhynchus mykiss, Walbaum, 1792) caused by Fipronil (FP) insecticide were investigated using different biomarkers (Hematology parameters, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), malondialdehyde (MDA), paraoxonase (PON), arylesterase (ARE), myeleperoxidase (MPO), micronucleus (MN), 8-hydroxy-2-deoxyguanosine (8-OHdG)) level and caspase-3 activity. Statistically significant alterations in hematology parameters occurred with FP effect. In blood tissue, dose-dependent inhibition was determined in SOD-CAT-GPX-PON and ARE enzyme activities, but MDA and MPO were induced statistically significant. The results of MN assay were compared with the control group and it was obtained that genotoxicity of different dose groups was similar. The level of 8-OHdG and the activity and caspase-3 examined in blood tissue was increased depending on the dose. It was determined with different biomarkers that this insecticide caused physiological stress changes in the tissues examined.

Expression of 8-OHdG in Zosterisessor ophiocephalus from the Venetian lagoon, Italy

The aim of the present work was to evaluate the expression of 8-OHdG (8-hydroxy-2'-deoxyguanosine) in the benthic fish Zosterisessor ophiocephalus collected in two differently polluted sites of the Venetian lagoon (Porto Marghera and Caroman). We compared our data on 8-OHdG with those of CYP1A (Cytochrome P450, family 1, subfamily A, polypeptide 1), which is a well known biomarker for detoxification of contaminants. Immunohistochemistry with an antibody to 8-OHdG showed immunopositivity in nuclei of hepatocytes as well as in melanomacrophage centres of spleen and kidney, whereas an anti-CYP1A antibody exhibited positive immunostaining in the liver, kidney and ovary. The liver of males showed higher expression of both proteins than females. In animals from Porto Marghera site, the enzymatic assay for 8-OHdG exhibited higher levels in liver of males than in females. Western Blot analysis using the antibody anti-CYP1A recognized the presence of a band of about 60 kDa in the liver of males and females. Males exhibited a strong band, whereas in females the band showed a lower intensity. By using Real-Time PCR, the mRNA expression of CYP1A did not show any differences between males and females from each site, but it was at borderline significance level. Comparing the two sites, mRNA expression of CYP1A was significantly higher in the liver of both males and females from Porto Marghera than that of Caroman. The present data suggest that pollutants are bio-available as demonstrated by our biomarker analyses and may have a harmful effect on aquatic organisms such as Z. ophiocephalus. We report that the highest levels of hepatic 8-OHdG and CYP1A expression were detected in males, showing clear gender specificity.

Proposed model for in vitro interaction between fenitrothion and DNA, by using competitive fluorescence, (31)P NMR, (1)H NMR, FT-IR, CD and molecular modeling

In this work we proposed a model for in vitro interaction of fenitrothion (FEN) with calf thymus-DNA by combination of multispectroscopic and two dimensional molecular modeling (ONIOM) methods. The circular dichroism results showed that FEN changes the conformation of B-DNA and caused some changes to C-DNA form. The FT-IR results confirmed a partial intercalation between FEN and edges of all base pairs. The competitive fluorescence, using methylene blue as fluorescence probe, in the presence of increasing amounts of FEN, revealed that FEN is able to release the non-intercalated methylene blue from the DNA. The weak chemical shift and peak broadening of (1)H NMR spectrum of FEN in the presence of DNA confirmed a non-intercalation mode. The (31)P NMR showed that FEN interacts more with DNA via its -NO2 moiety. The ONIOM, based on the hybridization of QM/MM (DFT, 6.31++G (d,p)/UFF) methodology, was also performed by Gaussian 2003 package. The results revealed that the interaction is base sequence dependent, and FEN interacts more with AT base sequences.

The protective role of vitamin E on gill and liver tissue histopathology and micronucleus frequencies in peripheral erythrocytes of Oreochromis niloticus exposed to deltamethrin

Deltamethrin, is a commonly used pyrethroid pesticide. Vitamin E is a antioxidant that plays an important role in protecting cells against toxicity by inactivating free radicals generated following pesticides exposure. Therefore, it was evaluated whether deltamethrin induced histopathological changes and nuclear abnormalities using micronucleus test in Oreochromis niloticus, and the possible protective effect of vitamin E against deltamethrin inducing adverse effects in O. niloticus were investigated. Fish was fed with no pesticide+control diet, no pesticide+vitamin E-supplemented diet, 1.45μg/l deltamethrin+control diet, 1.45μg/l deltamethrin+vitamin E-supplemented diet for 30 days. Pesticide and diet quality made an impact on histopathological lesions. In treatments of deltamethrin, group fed with control diet showed much greater damage in comparison with group fed with vitamin E supplemented diet. Vitamin E decreased some histopathological changes induced by deltamethrin, but did not confer complete protection. Deltamethrin treatment has been shown to results in a significant increase in the frequency of micronucleus. However, coadministration of deltamethrin and vitamin E showed decrease in the frequency of micronucleus as compared to deltamethrin treated fish. Our results indicate that, the MN assay and histopathology can be used as bioassays for monitoring pollution in aquatic medium. On the other hand, it was observed that vitamin E decreased the genotoxicity and histopathological changes induced by deltamethrin.