Genotoxic effects of Roundup on the fish Prochilodus lineatus

Associations between metals and metalloids, oxidative stress and genotoxicity in Nurse sharks Ginglymostoma cirratum from the Brazilian Amazon Coast

Elasmobranch populations have significantly declined in recent decades due to anthropogenic activities, with chemical contamination comprising one of the main threats to this group. Although some biochemical biomarkers have been utilized to assess elasmobranch health, especially concerning metal and metalloid contamination, associations with genotoxic biomarkers are still scarce and non-existent for Brazilian Amazon coast sharks. Herein, metals, metalloids, reduced glutathione (GSH), glutathione S-transferase (GST), metallothionein (MT), and nuclear anomalies (micronucleus, nuclear buds, and bilobed cells) were determined in gills, liver, and muscle tissues of Nurse sharks (Ginglymostoma cirratum) from the São Marcos Estuarine Complex, Maranhão, Brazil. Females exhibited significantly higher As concentrations in muscle (23.14 ± 13.98 μg g-1) and gills (4.53 ± 2.10 μg g-1) compared to males (3.98 ± 2.61 μg g-1 and 1.51 ± 0.41 μg g-1, respectively) (p < 0.05). Males showed higher Se concentrations in muscle (0.52 ± 0.02 μg g-1) compared to females (0.32 ± 0.09 μg g-1) (p < 0.05), while Rb levels were higher in male liver (0.28 ± 0.05 μg g-1) than in females (0.18 ± 0.04 μg g-1) (p = 0.001). No significant differences were observed for Hg, Ti or rare earth elements (Ce and La) between sexes (p > 0.05). Higher GSH concentrations and GST activities were noted in gills and liver, while MT concentrations were higher in muscle. Low genotoxic damage frequency was observed, likely due to the species' sedentary lifestyle and efficient DNA repair system. Moderate to strong correlations between metals/metalloids and biochemical/genotoxic responses were detected, particularly in females, highlighting the protective role of GST against DNA damage. Protective effects of Se against Hg were observed in the liver. Metal concentrations did not exceed regulatory limits, although bioaccumulation patterns and physiological responses suggest that Nurse sharks are exposed to environmental contamination, with As and Se accumulation.

Multi-Biomarkers' Responses in Gills of Oreochromis niloticus Exposed to Glyphosate and Polyethylene Microplastic, Isolated and in Mixture

Microplastics (MPs) and glyphosate-based herbicides (GBH) are among the most common contaminants in aquatic environments. In Brazilian rivers, both contaminants were found in elevated levels, leading to a high probability of their association, which can alter their individual effects and potentially intensify their toxicity. This study evaluated the isolated and combined effects of polyethylene microplastics (PE-MPs) and GBH on Oreochromis niloticus using multi-biomarkers of toxicity. The fish were subjected to a 96-h exposure period, with concentrations set based either isolated, PE-MPs group (5 mg L-1), GBH group (5 mg L-1), or in a group of associated contaminants (GAC), PE-MP + GBH (5 mg L-1 + 5 mg L-1). Toxicity effects were evaluated using biochemical, cytogenetic, hematological, and histopathological biomarkers. We observed change in erythrocyte parameters leading to macrocytic normochromic anemia in GAC. Leukocyte parameters indicate a nonspecific immunosuppression caused by the exposure of associated contaminants, besides the attempts to repair damage caused by PE-MPs. Histopathological markers indicate damage to tissues exposed to contaminants. Besides, there were morphophysiological adjustments on gills, with proliferation and hypertrophy of mitochondria-rich cells on GBH and GAC, besides epithelium ruptures, which were mostly present in the exposed groups. Therefore, this study indicates that PE-MPs and GBHs present toxic effects in O. niloticus with the used concentrations, intensified by the association of contaminants. Thus, multi-biomarkers were useful key to verify toxicity, providing data to the investigation of high levels of contaminant's mixture toxicity present in aquatic environments.

Effects of Low Concentration of Glyphosate-Based Herbicide on Genotoxic, Oxidative, Inflammatory, and Behavioral Meters in Danio rerio (Teleostei and Cyprinidae)

The glyphosate herbicide is a pesticide widely used in the world and can contaminate soil, air, and water. The objective of this work was to evaluate the toxicity of a glyphosate-based herbicide (GBH) in zebrafish (Danio rerio). Fish were exposed to different concentrations of GBH (0, 50, 250, and 500 µg/L) for 96 hours. Brain, liver, and blood were collected for biochemical and genotoxicity analyses, and behavioral tests were performed. The results showed that there was a reduction in the activity of the antioxidant enzymes of catalase (CAT) and glutathione-S-transferase (GST) in the liver at all concentrations and at the highest concentration in the brain. There was also a reduction in lipid peroxidation in the liver at all concentrations of glyphosate. There was an increase in micronuclei in the blood at the 500 µg/L concentration. However, the count of nuclear abnormalities showed no differences from the control. Interleukin-1beta (IL-1β) generation was inhibited at all concentrations in the liver and at the highest concentration in the brain. No significant differences were found in the behavioral test compared to the control. The results showed that acute exposure to GBH promoted an inflammatory event, which reduced the efficiency of antioxidants, thus producing a disturbance in tissues, mainly in the liver, causing immunosuppression and generating genotoxicity.

The effect of acute exposure of yellowtail tetra fish Astyanax lacustris (Lütken, 1875) to the glyphosate-based herbicide Templo®

The herbicide glyphosate (N-(phosphonomethyl)glycine) efficiently eliminates weeds, is frequently present in surface waters, and may damage the health of various non-target organisms. The main objective of this study was to investigate cytotoxic and genotoxic effects in erythrocytes, DNA, and chromosomes of native South American fish Astyanax lacustris exposed to a glyphosate-based commercial herbicide Templo®. The presenty study evaluated the presence of micronuclei (MN), chromosomal aberrations (CA), DNA damage revealed by comet assay, and cellular morphological changes (CMC) as biomarkers. The A. lacustris specimens were exposed to Templo® for 96 h at concentrations below the permitted Brazilian legislation for freshwater environments. The glyphosate-based herbicide caused MN formation, an increased incidence of CA, DNA damage, and several types of CMC in all tested concentrations on A. lacustris. Notably, analyses were significant (p<0.05) for all concentrations, except in the frequency mean of MN at 3.7 µg/L. Thus, considering the intensive use of commercial glyphosate formulations in crops, the herbicide Templo® represents a potential risk of genotoxicity and cytotoxicity for aquatic organisms. Therefore, environmental protection agencies must review regulations for glyphosate-based herbicides in freshwater environments.

The toxicity assessment of phosmet on development, reproduction, and gene expression in Daphnia magna

The use of pesticides to control pests, weeds, and diseases or to regulate plant growth is indispensable in agricultural production. However, the excessive use of these chemicals has led to significant concern about their potential negative impacts on health and the environment. Phosmet is one such pesticide that is commonly used on plants and animals against cold moth, aphids, mites, suckers, and fruit flies. Here, we investigated the effects of phosmet on a model organism, Daphnia magna using acute and chronic toxicity endpoints such as lethality, mobility, genotoxicity, reproduction, and gene expression. We performed survival experiments in six-well plates at seven different concentrations (0.01, 0.1, 1, 10, 25, 50, 100 μM) as well as the control in three replicates. We observed statistically significant mortality rates at 25 µM and above upon 24 h of exposure, and at 1 µM and above following 48 h of exposure. Genotoxicity analysis, reproduction assay and qPCR analysis were carried out at concentrations of 0.01 and 0.1 μM phosmet as these concentrations did not show any lethality. Comet assay showed that exposure to phosmet resulted in significant DNA damage in the cells. Interestingly, 0.1 μM phosmet produced more offspring per adult compared to the control group indicating a hormetic response. Gene expression profiles demonstrated several genes involved in different physiological pathways, including oxidative stress, detoxification, immune system, hypoxia and iron homeostasis. Taken together, our results indicate that phosmet has negative effects on Daphnia magna in a dose- and time-dependent manner and could also induce lethal and physiological toxicities to other aquatic organisms.

Mutagenic effects of a commercial glyphosate-based herbicide formulation on the soil filamentous fungus Aspergillus nidulans depending on the mode of exposure

Glyphosate-based herbicides (GBH) are the most used pesticides worldwide. This widespread dissemination raises the question of non-target effects on a wide range of organisms, including soil micro-organisms. Despite a large body of scientific studies reporting the harmful effects of GBHs, the health and environmental safety of glyphosate and its commercial formulations remains controversial. In particular, contradictory results have been obtained on the possible genotoxicity of these herbicides depending on the organisms or biological systems tested, the modes and durations of exposure and the sensitivity of the detection technique used. We previously showed that the well-characterized soil filamentous fungus Aspergillus nidulans was highly affected by a commercial GBH formulation containing 450 g/L of glyphosate (R450), even when used at doses far below the agricultural application rate. In the present study, we analysed the possible mutagenicity of R450 in A. nidulans by screening for specific mutants after different modes of exposure to the herbicide. R450 was found to exert a mutagenic effect only after repeated exposure during growth on agar-medium, and depending on the metabolic status of the tested strain. The nature of some mutants and their ability to tolerate the herbicide better than did the wild-type strain suggested that their emergence may reflect an adaptive response of the fungus to offset the herbicide effects. The use of a non-selective molecular approach, the quantitative random amplified polymorphic DNA (RAPD-qPCR), showed that R450 could also exert a mutagenic effect after a one-shot overnight exposure during growth in liquid culture. However, this effect was subtle and no longer detectable when the fungus had previously been repeatedly exposed to the herbicide on a solid medium. This indicated an elevation of the sensitivity threshold of A. nidulans to the R450 mutagenicity, and thus confirmed the adaptive capacity of the fungus to the herbicide.

Assessment of textile industry effluent (untreated and microbially treated) induced genotoxic, haematological, biochemical, histopathological and ultrastructural alterations in fresh water fish Channa punctata

The unregulated expulsion of untreated textile water into water bodies is a major hazard to aquatic ecosystems. The present investigation was contrived to estimate the impact of textile dye bath effluent (untreated and microbially treated) on fish Channa punctata. Untreated effluent-exposed fish showed extremely altered behaviour (air gulping, erratic and speedy movements, increased opercular activity) and morphology (deposition of dyes on skin and scales, high pigmentation, mucus exudation). Significantly increased micronuclei (1.61-, 1.28-, 1.38-fold) and aberrant cell frequency (1.37-, 1.45-, 1.28-fold) was observed in untreated group as compared to treated group after 15, 30, and 45 days of exposure. Tail length, % tail intensity, tail moment and olive tail moment were also enhanced in all the exposed tissues. However, maximum damage was noticed in gill tissues showing 1.19-, 1.37-, 1.34- and 1.50-fold increased TL, %TI, TM and OTM in untreated group as compared to treated group after 45 days of exposure. On comparing untreated and treated groups, increased blood parameters and significantly reduced white blood cell count (WBC) were noticed in treated group. Significantly enhanced alterations in biochemical parameters were also analysed in untreated group. Reduced alterations in enzymological levels of fishes exposed to treated effluent indicate lesser toxic nature of the degraded metabolites of dye. Histological analysis in fishes exposed to untreated effluent showed several deformities in liver (necrosis, congestion, fusion of cells and melanomacrophage infiltration) and gill tissues (necrosis, bending of lamellae and severe aneurysm). Scanning electron microscopy (SEM) analysis further reaffirmed the pathologies observed in histological analysis. Fewer structural alterations were noticed in treated effluent fishes. The results concluded that untreated effluent inflicted toxicity potential on morphology as well as physiological defects in fish, and the severity increased with increasing duration of exposure, whereas reduction in toxicity in microbially treated groups can be analysed for aquacultural purposes owing to their lesser toxic nature.

Differences in biomarker responses and chemical contamination among three flatfish species in the Bay of Seine (NE Atlantic)

To assess the potential of the sole as sentinel species for ecotoxicological monitoring, the present study compares contaminant levels and biological responses with two closely related flatfish species: the common dab and European flounder. Trace metals, organic contaminants and biomarkers were measured in the three flatfish species collected during the same oceanographic cruise in the Bay of Seine (France). Overall, sole showed lower concentrations of Hg, met-Hg, Cd, Zn and PBDE (lw), higher concentrations of Ag, Cu, PFOS (ww), PCBs, p,p'-DDE (lw) and OH-pyrene, a higher ability to metabolize PBDEs and higher genotoxic (Comet, Micronuclei) and neurotoxic (AChE inhibition) alterations. Sole was the species most frequently occurring in the bay and appeared sensitive to chemical contamination. We therefore recommend promoting the use of the common sole for ecotoxicological monitoring.

Roundup® disrupts tissue architecture, attenuates Na+/K+-ATPase expression, and induces protein oxidation/nitration, cellular apoptosis, and antioxidant enzyme expressions in the gills of goldfish, Carassius auratus

Extensive agricultural activities to feed the growing population are one major driving force behind aquatic pollution. Different types of pesticides are used in farmlands to increase crop production and wash up into water bodies. Glyphosate-based herbicide Roundup® is one of the most used pesticides in the United States; however, its effects on teleost species are still poorly understood. This study focused on the effects of environmentally relevant concentrations of Roundup exposure (low- and high-dose: 0.5 and 5 μg/L for 2-week) on Na+/K+-ATPase (NKA, a biomarker for sodium‑potassium ion pump efficacy), cytochrome P450-1A (CYP1A, a monooxygenase enzyme), 2,4-dinitrophenyl protein (DNP, a biomarker for protein oxidation), 3-nitrotyrosine protein (NTP, a biomarker for protein nitration), superoxidase dismutase (SOD, an antioxidant enzyme), catalase (CAT, an antioxidant enzyme) expressions, and cellular apoptosis in the gills of goldfish. Histopathological and in situ TUNEL analyses showed widespread tissue damage, including lamellar fusion, loss of gill architecture, club shape of primary lamellae, mucous formation, and distortion in the epithelium layer, as well as apoptotic nuclei in gills. Immunohistochemical and qRT-PCR analyses provided insights into the expressions of molecular indicators in gills. Fish exposed to Roundup exhibited a significant (P < 0.05) downregulation of NKA expression in gills. Additionally, we observed upregulation of CYP1A, DNP, NTP, SOD, and CAT expressions in the gills of goldfish. Overall, our results suggest that exposure to Roundup causes disruption of gill architecture, induces protein oxidation/nitration and cellular apoptosis, and alters prooxidant-antioxidant homeostasis in tissues, which may lead to reduced fitness and survivability of teleost species.

Molecular and biochemical biomarkers in the American oyster Crassostrea virginica exposed to herbicide Roundup® at high temperature

Aquatic organisms are frequently exposed to various environmental stressors. Thus, the effects of high temperatures and herbicides on aquatic organisms are a major subject of interest. In this study, we studied the effects of short-term exposure (1 week) to Roundup®, a glyphosate-based herbicide (concentrations: 0.5 and 5 µg/L), on the morphology of gills, digestive glands, and connective tissues, and the expression of heat shock protein-70 (HSP70, a chaperone protein), cytochrome P450 (CYP450, a biomarker of environmental contaminants), dinitrophenyl protein (DNP, a biomarker of protein oxidation), nitrotyrosine protein (NTP, a biomarker of protein nitration), antioxidant enzymes such as superoxidase dismutase (SOD) and catalase (CAT) in tissues of American oyster, Crassostrea virginica (Gmelin, 1791) maintained at high temperature (30 °C). Histological analyses showed an increase in mucous production in the gills and digestive glands, and in hemocyte aggregation in the connective tissues as well as a structural change of lumen in the digestive glands of oysters exposed to Roundup. Immunohistochemical and quantitative RT-PCR analyses showed significant (P < 0.05) increases in HSP70, CYP450, DNP, NTP, CAT, and SOD mRNA and protein expressions in the tissues of oysters exposed to Roundup. Taken together, these results suggest that exposure to Roundup at high temperature induces overproduction of reactive oxygen species/reactive nitrogen species which in turn leads to altered prooxidant-antioxidant activity in oyster tissues. Moreover, our results provide new information on protein oxidation/nitration and antioxidant-dependent mechanisms for HSP70 and CYP450 regulations in oysters exposed to Roundup at high temperature.

Novel data on genotoxic assessment of bismuth sulfide nanoflowers in common carp Cyprinus carpio

The environmental impacts and risks of nanomaterials that are commonly used in different technologies are of great concern as their toxic effects on the aquatic ecosystem remain unclear. In this study, bismuth sulfide (Bi2S3) nanoflowers (nfs) were synthesized using a microwave-based hydrothermal process, and their genotoxic effects were investigated in the common carp, Cyprinus carpio. Bi2S3 nanoflowers were applied to common carp for 96 h. LC50 value (LC50 = 350 mg/L-1) was determined for acute toxicity with probit analysis, and three sublethal concentrations (35, 87, and 175 mg/L-1) were selected accordingly for genotoxicity tests. Such LC50 value - 350 mg L-1 for the common carp makes these nanoflowers non-toxic to aquatic organisms according to the EU-Directive 93/67/EEC classification scheme. Toxicological evaluations of the sublethal concentrations of Bi2S3 nanoflowers demonstrated that the 35 and 87 mg L-1 Bi2S3nfs groups were generally harmless and similar to the control group. Only the 175 mg L-1 Bi2S3nfs group had significant DNA damage frequency and nuclear abnormalities than the control and other Bi2S3nfs groups. To the best of our knowledge, this is a novel data on genotoxicity reported for fish species exposed to Bi2S3 nanoflowers; however, further systematic studies need to be performed to fully estimate the effects of Bi2S3 nanoflowers on aquatic life.

A sub-chronic feeding study of dual toxin insect-resistant transgenic maize (CEMB-413) on Wistar rats

Genetically modified (GM) crops expressing insecticidal crystal proteins are widely accepted worldwide, but their commercial utilization demands comprehensive risk assessment studies. A 90-day risk assessment study was conducted on Wistar rats fed with GM maize (CEMB-413) expressing binary insect-resistant genes (cry1Ac and cry2Ab) at low (30%) and high (50%) dose along with a control diet group. The study used fifty Wistar rats randomly distributed in five treatment groups. Our study revealed that compared to controls, GM diet had no adverse effects on animal's health, including body weight, food consumption, clinical pathological parameters, serum hormone levels and histological parameters of testes and ovaries of rats. Differences were observed in transcripts levels of fertility related genes, but these were independent of treatment with GM diet.

Genotoxic effects of polycyclic aromatic hydrocarbons (PAHs) present in vehicle-wash wastewater on grass carp (Ctenopharyngodon idella) and freshwater mussels (Anodonta cygnea)

Vehicle-wash wastewater (VWW) contains high levels of various petrochemicals such as polycyclic aromatic hydrocarbons (PAHs), a carcinogenic category of organic substances. However, the genotoxic effects of PAHs present in VWW remain largely unknown. We explored the genotoxic effects of PAHs present in VWW on fish grass carp (Ctenopharyngodon idella) and freshwater mussels (Anodonta cygnea). Fish and freshwater mussels were divided into control and exposed groups, the prior groups were treated at weekly intervals with clean water, and the latter with Σ16PAHs contaminated VWW for up to four weeks. The samples of blood from fish and haemolymph from freshwater mussels were collected and analyzed using the comet assay technique. Results exhibited that in control fish and freshwater mussel groups the genotoxicity decreased with every week passing following the order of W1 > W2 > W3 > W4, ranging from 8.33 ± 3.06 to 25.3 ± 4.62 and from 46.0 ± 6.93 to 7.67 ± 3.79, respectively. The exposed fish and freshwater mussel groups indicated an increase in genotoxicity with increasing week intervals with an order of W4 > W3 > W2 > W1, ranging from 55.7 ± 11.9 to 128.3 ± 10.0 and from 112.7 ± 8.50 to 183.3 ± 10.1, respectively. The genotoxic effect of Σ16PAHs on fish was comparatively lower than on freshwater mussels. This study elucidates that VWW is highly genotoxic and should be treated before discharging into aquatic ecosystems.

DNA damage and oxidative stress in gill cells of Cnesterodon decemmaculatus exposed to pesticides by runoff source in an agricultural basin

In our country, great concern exists about diffuse pollution cause by the great use of pesticides in rural environments. A thorough analysis is needed to generate information, know the real situation and thus, be able to make decisions with the purpose of reducing environmental pollution. In situ bioassays have been carried out using Cnesterodon decemmaculatus within limnocorrals located in a surface natural water system that receives rainfall excess flowing from an agricultural basin with a typical crop rotation, including corn, wheat and soy. Specimens were taken from the limnocorrals 72 h after a probed natural runoff event toward the water body, and the gill cells were used to evaluate the DNA damage (comet assay, CA), catalase enzyme activity (CAT), and lipid peroxidation (LPO). In addition, the physicochemical analysis of the water (pH, temperature) and the presence and concentration of pesticides were carried out. The results showed significant differences on DNA damage and oxidative stress on the gill cells of the exposed fish compared to controls, being the combination of the rain regime and the mixtures of pesticides used in corn and soy more toxic than in wheat. These results highlight the necessity to understand detrimental processes caused by pesticides used in extensive systems of primary production, in order to prevent and minimize diffuse contamination, contributing to environmental recovery and sustainability.

"Fishcide" effect of the fungicide difenoconazole in freshwater fish (Labeo rohita): A multi-endpoint approach

Difenoconazole is widely used to protect crops, fruits, and vegetables. However, this fungicide can enter aquatic environments and cause harmful effects to non-target organisms and induce little-known biological disorders. Thus, aiming to expand our knowledge about the ecotoxicity of difenoconazole on freshwater ichthyofauna, we aimed to determine the median lethal concentration (LC₅₀) of difenoconazole and evaluate its possible impacts from different toxicity biomarkers, using freshwater fish Labeo rohita as a model system. Using the probit analysis method, the 96 h LC₅₀ value of difenoconazole in the fish was calculated as 4.5 mg L^-1. Posteriorly, fish were exposed to two sublethal concentrations (0.45 mg L^-1 1/10th and 0.9 mg L^-1 1/5th LC₅₀ value) for 21 days. A significant reduction of superoxide dismutase (SOD) and catalase (CAT) activity was noted in the gill, liver, and kidneys of fish compared to the control groups. The level of glutathione-S-transferase (GST) and lipid peroxidation (LPO) activity was higher in all vital tissues of difenoconazole-treated fish. Histological alterations in the gill include epithelial lifting, lamellar fusion, hypertrophy, and epithelial necrosis. At the same time, the liver showed pyknotic nucleus, vacuolation, cellular edema and tubular necrosis, shrinkage of glomeruli, vacuolation, and pyknotic nuclei in the kidney. DNA damage was increased significantly with tail formation based on the concentration and time-dependent manner. Therefore, our study confirms that the exposure of L. rohita to difenoconazole induces negative biological consequences and sheds light on the danger of this fungicide for freshwater fish species. We believe that studies like ours can support actions and strategies for the remediation/mitigation of aquatic pollution by difenoconazole and for the conservation of freshwater ichthyofauna.

DNA Damage and Repair in different Tissues of Fresh Water Fish, <i>Channa punctata</i> after Acute and Subchronic Exposure to bisphenol A

The present study was conducted to investigate the genotoxic effect of Bis-Phenol A (BPA) after acute and subchronic exposure in different tissues of Channa punctata. The recovery in DNA damage was also ascertained after 30 days of cessation of exposure. Fish were exposed to different sublethal concentrations of BPA along with two controls i.e., with positive (acetone) and negative (water) controls for 96h (acute exposure) and 60 days (subchronic exposure) and after that fish were allowed to recover for 30 days in freshwater. The blood, liver, and gill tissue samples were collected at 24, 48, 72 and 96h for acute exposure and after 20, 40, and 60 days post-exposure for subchronic exposure. Exposed groups showed significantly higher DNA damage in both acute and subchronic exposure as compared to control groups. In the case of acute exposure, the highest damage was observed at 24 h of exposure followed by a decline in the value of all the parameters, while in the later hours of exposure these values further increased. On the other hand, in the case of sub-chronic exposure, the highest damage was observed after 60 days of exposure. Recovery experiment showed a decrease in the values of all the parameters studied. The result of the study clearly showed that BPA caused DNA damage in Channa punctata after acute as well as subchronic exposure.

Urbanity as a source of genotoxicity in the synanthropic Kelp Gull (Larus dominicanus)

Increases in human population lead to an increase in urban wastes, which could affect wildlife in several ways. Urban pollutants can affect erythrocytes of birds generating morphological membrane and nuclear anomalies. The Kelp Gull (Larus dominicanus) is an opportunistic species, which take advantage of urban environments, thus being highly exposed to environmental pollution. In northeastern Patagonia, the dynamic of the waste management was transformed in the last decade and consequently, gulls changed their movements in response to changes in waste management systems. The food available to the seagulls went from being a mixture of urban/fishing discards until 2015, when this landfill closures, to being domestic urban offerings. In order of evaluating genotoxicity and changes in pollutants exposition due to these changes, we analyzed the frequencies of erythrocytes nuclear abnormalities and micronuclei (ENAs and MN respectively) in 58 blood smears from adults extracted during the non-breeding season in two periods in landfills with different waste compositions: a mixed landfill (ML) in 2013 before closure (n = 24) versus an urban landfill (UL) (n = 34) in 2021. We found that the Kelp Gull showed high values of abnormalities with an average of 151.5 /10,000 RBC in comparison with other seabird species. The bud and notched types of ENAs were the most prevalent abnormalities in both sites. We did not find significate differences in the overall abnormality frequency between sites, however we found significant higher frequencies in displaced and tailed types of ENAs in ML. We also found poikilocytosis, as seen previously in other animals exposed experimentally to pollutants such as metals and crude oil. Cellular abnormalities found in the Kelp Gull suggest an exposition of individuals to pollutants in foraging areas. The hemispheric distribution and the synanthropic characteristics of the species denote its importance as a suitable global monitor of genotoxicity.

Bioaccumulation of trace metals and genotoxicity responses in Liza aurata as an indicator of industrial pollution

Heavy metal contamination in the coastal and marine ecosystems is becoming a serious risk to aquatic organisms and humans. This study reports the effects, including genetic damage, of accumulations of trace metals on Liza aurata, which is used as a bio-indicator species, in the Payas coast of Iskenderun Bay, north-eastern Mediterranean by COMET Assay. L. aurata were seasonally collected from a sampling site and a reference site for one year. Physicochemical parameters in water and trace metals in the tissues of fish collected from these sites were determined by electrochemical techniques. High DNA damage frequency in L. aurata was observed along the Payas coast of Iskenderun Bay compared to the reference site because of pollutants. The detected high levels of Cd, Pb, Fe and Cu accumulation in L. aurata exceed the maximum levels allowed by the national and international limit values. Significant positive correlations between Cd, Pb, Hg, Cr, Fe, Zn, and Cu accumulations and DNA damage parameters were observed in the present study. Additionally, we first reported the successful use of the electrochemical technique in the determination of trace metal concentrations in mullet. Moreover, L. aurata constitutes a key tool as a sentinel organism for biomonitoring of coastal ecosystems.

Cyclophosphamide alters the behaviors of adult Zebrafish via neurotransmitters and gut microbiota

Cyclophosphamide, one of the earliest prescribed alkylating anticancer drugs, has been frequently detected in aquatic environments. However, its effects on fish behavior and associated mechanisms remain largely unknown. In this study, the behaviors, neurochemicals, and gut microbiota of adult zebrafish were investigated after 2 months of exposure to CP at 0.05, 0.5, 5, and 50 µg/L. Behavioral assays revealed that CP increased locomotion and anxiety, and decreased the cognition of zebrafish. The alteration of neurotransmitters and related gene expressions in the dopamine and gamma-aminobutyric acid pathways induced by CP may be responsible for the observed changes in locomotion and cognition of adult zebrafish. Meanwhile, CP increased the anxiety of adult zebrafish through the serotonin, acetylcholine, and histamine pathways in the brain. In addition, increased abundances of Fusobacteriales, Reyanellales, Staphylococcales, Rhodobacterals, and Patescibateria in the intestine at the CP-50 treatment were observed. The study has demonstrated that CP affects the locomotion, anxiety, and cognition in zebrafish, which might be linked with the dysfunction of neurochemicals in the brain. This study further suggests that the gut-brain axis might interact to modulate fish behaviors upon exposure to CP (maybe other organic pollutants). Further research is warranted to test this hypothesis.

Ecogenotoxicological studies for an early toxicity screening and monitoring in Epinephalus chlorostigma and Scamberomorus commerson

The study was planned to investigate DNA fragmentation in fish to screen aquatic toxicity and in Epinephalus chlorostigma and Scamberomorus commerson collected from Red sea near Jizan, Saudi Arabia from three locations “(Corniche North park: “16.92161, 42.54631; Jizan Port: 16.874, 42.54952” N and Jizan Economic City: 17.26589, 42.34738“ ”)“ were used as a case study for the application of comet assay. The study area of the Red Sea is polluted due to anthropogenic activities and the disposal of wastes from multiple sources. Comet and micronucleus assays were used to detect genotoxicity in these fish species harvested from three sites. The concentration of Pb, Cr, Zn, Mn, Cu, Cd, Sn, and Hg was higher in the water samples collected from the polluted site compared to the non-polluted site of the Red sea. Comet assay for S. commerson showed significant (p < 0.05) genetic damage about 44.33 ± 3.03% DNA in comet tail at site S1. It was subsequently reduced to 31.71 ± 3.52% and 22.11 ± 2.52% at sites S2 and S3. E. chlorostigma also showed significant DNA in comet tail as 17.34 ± 2.19%, 11.87 ± 3.01%, and 36.41 ± 3.98% at site S1-S3, respectively. Significant (p < 0.05) DNA damage was observed in the fishes procured from non-polluted locations and upstream locations. The micronucleus induction in E. chlorostigma was recorded as 23.20 ± 4.19 and 2.20 ± 0.58%, respectively, non-polluted and polluted sites. S. commerson exhibited significant differences between polluted and non-polluted sites (44.80 ± 3.73 and 8.20 ± 2.20‰) polluted and upstream (44.80 ± 3.73 and 20.60 ± 4.02‰), respectively. A significant difference was obtained between E. chlorostigma and S. commerson for nuclear abnormalities S. commerson showed higher frequencies for nuclear deformities than E. chlorostigma. S. commerson showed substantial micronucleus induction frequencies collected from an area of low pollution intensity (upstream). This study showed that E. clorostigma and S. commerson could be successfully used as a bioindicator to determine the health of the Red Sea through the most specific assays such as comet and micronucleus tests as an early warning and to devise the monitoring strategies to ensure a safe supply of fish for human consumption.

Cyclophosphamide affects eye development and locomotion in zebrafish (Danio rerio)

Cyclophosphamide (CP) is a broad-spectrum anticancer drug and has been frequently detected in aquatic environments due to its incomplete removal by wastewater treatment facilities and slow degradation in waters. Its toxicity in fish remains largely unknown. In this study, zebrafish eggs <4 h post fertilization (hpf) were exposed to CP at the concentrations from 0.5 to 50.0 μg/L until 168 hpf, and its toxicity was evaluated by biochemical, transcriptomic, and behavioral approaches. The results showed that malformation and mortality rates increased with CP concentrations. The 7-day malformation EC₅₀ and mortality (LC₃₀) by CP were calculated to be 86.8 μg/L and 7.5 mg/L, respectively. Inhibited startle response (light to dark) (a minimal of 19%) and reduced swimming velocity (a minimal of 30%) were observed in the CP-exposed larvae. The thicknesses of retinal ganglion layer, inner plexiform layer, and inner nuclear layer in the retina were increased after exposure to CP. Meanwhile, exposure to CP increased karyorrhexis and karyolysis in the liver tissue. Transcriptomic analysis identified 607 differentially expressed genes (DEGs) (159 up-regulated and 448 down-regulated). A significant reduction in the transcripts of sgk1 (the FoxO pathway), jun (the MAPK pathway), and diabloa (apoptosis pathway) were observed in the CP-treated larvae. This study has demonstrated that low concentrations of CP cause malformation, reduced swimming capacity, histopathological alterations in the retina and liver tissues, and interference on transcriptional expressions of key genes associated with different pathways. The ecological risk of CP and other anticancer drugs to aquatic organisms merits future investigation.

Effects on reproductive, biochemical and genotoxic parameters of herbicides 2,4-D and glyphosate in silver catfish (Rhamdia quelen)

The objective of this work was to evaluate the effects of the herbicides 2,4-D, glyphosate and the mixture of both on oxidative stress, genotoxicity and the rates of fertilization, hatching and larval normality in silver catfish. Exposure to glyphosate and the mixture of herbicides significantly decreased the fertilization of oocytes and the hatching of eggs. The different concentrations of 2,4-D and glyphosate, in addition to the mixture of both, did not affect the rates of larval normality, the activity of CAT, GST, LPO, and PCO. SOD activity was not evident in any of the treatments. Exposure to 2,4-D and the mixture of herbicides caused damage to the genetic material of larvae silver catfish. Our results show that although high concentrations of the herbicides were used, changes caused by them were detected in only some of the tested biomarkers.

Evaluation of the genotoxic, mutagenic, and histopathological hepatic effects of polyoxyethylene amine (POEA) and glyphosate on Dendropsophus minutus tadpoles

Herbicides improve the productivity of a monoculture by eliminating weeds, although they may also be toxic and have negative effects on non-target organisms, such as amphibians. The present study evaluated the genotoxic, mutagenic, and histopathological hepatic responses of Dendropsophus minutus tadpoles to acute exposure (96 h) to the herbicide glyphosate (GLY, 65, 130, 260 and 520 μg/L) and the surfactant polyoxyethylene amine (POEA, 1.25, 2.5, 5 and 10 μg/L). On average, 174 % more genomic damage was observed in the tadpoles exposed to all concentrations of POEA in comparison with the control, while up to seven times more micronuclei were recorded, on average, at a concentration of 5 μg/L of POEA. All the individuals exposed to 10 μg/L of POEA died. The tadpoles exposed to GLY presented 165 % more DNA damage than the control, on average, at the highest concentrations (260 and 520 μg/L), and up to six times more micronuclei at 520 μg/L. The Erythrocyte Nuclear Abnormality test (ENA) detected a relatively high frequency of cells with lobed nuclei in the tadpoles expose to POEA at 5 μg/L and binucleated cells in those exposed to GLY at 520 μg/L. The hepatic histopathological observations revealed several types of lesions in the tadpoles exposed to both GLY and POEA. Overall, then, the results of the study indicate that both GLY and POEA have potential genotoxic, mutagenic, and hepatotoxic effects in D. minutus tadpoles. We emphasize the need for further studies to monitor the amphibian populations, such as those of D. minutus, which breed in aquatic environments associated with agricultural areas. The release of pollutants into natural habitats may have significant long-term impacts on the survival of anuran tadpoles.

Alterations in blood parameters, DNA damage, oxidative stress and antioxidant enzymes and immune-related genes expression in Nile tilapia (Oreochromis niloticus) exposed to glyphosate-based herbicide

In this study, effects of different concentrations (0, 5, 10, 20, 30, and 40 mg/L) of glyphosate-based herbicide (GBH) on Nile tilapia (Oreochromis niloticus) were investigated after a 14-day of exposure. After determination of LC50 value, effects of GBH on hematological and serum biochemical parameters in blood samples, DNA damage, lipid peroxidation and catalase activity in liver tissues, expression levels of antioxidant enzyme-related genes (SOD, CAT, GPx, and GST) and immune-related genes (TGF-β, TGF-α and IL1-β) were evaluated. The LC50 value has been found as 44.4 mg/L for GBH. GBH exposure at all concentrations caused alterations in blood parameters. GBH induced oxidative stress in liver and DNA damage in blood. Antioxidant enzyme-related genes were significantly up-regulated to suppress oxidative stress. On the other hand, the expression levels of immune-related genes decreased in fish exposure to particularly ≥20 mg/L GBH.

Multibiomarker responses to polycyclic aromatic hydrocarbons and microplastics in thumbprint emperor Lethrinus harak from a South Pacific locally managed marine area

To determine the baseline threat of microplastics and polycyclic aromatic hydrocarbons (PAHs) in an important seafood fish from Vueti Navakavu locally managed marine area, a multibiomarker risk assessment was conducted on the thumbprint emperor fish Lethrinus harak. Condition factor, a measure of relative general health condition of fish, was significantly lower in samples from the wet season compared to the dry season but no significant differences were observed for hepatosomatic index, a measure of relative stored energy/nutrition, between seasonal groups. PAHs levels of four metabolites in emperor fish from Fiji waters are reported here for the first time; seasonal groups showed no significant differences, but all samples presented levels of biliary PAHs. Each specimen also contained at least one microplastic in its gastrointestinal system; fibres were the predominant form-type and ingestion levels showed that more than 80% of fragment sizes were below 1.0 mm. Biochemical responses were observed for ethoxyresorufin-O-deethylase and glutathione S-transferase biotransformation activity, oxidative stress (glutathione peroxidase and glutathione reductase activity; lipid peroxidation) and genotoxicity (micronuclei assay). Though there were no statistically significant differences found, there were biological significances that were important to note; relatively low levels of pollutant exposure and low levels of biochemical responses showed enzymes response in thumbprint emperor were as expected to their roles in the body. In this multibiomarker approach, the observation of pollutants presence and histopathological injuries are considered biologically relevant from a toxicological perspective and serve as a baseline for future pollution studies in seafood fishes in Fiji, with site differences and the inclusion of fish species comparison. We recommend adopting a suite of biomarkers in future regional biomonitoring studies to develop holistic baseline information for other marine settings in Fiji and other Pacific Island countries.

Protective role of Spirulina platensis against glyphosate induced toxicity in marine mussel Mytilus galloprovincialis

Glyphosate is a toxic environmental pollutant that has the ability to induce biochemical and physiological alterations in living organisms. Several studies have focused on the research of protective techniques against the stress induced by this contaminant. In this context, we studied the protective effect of Spirulina against the disturbances induced by glyphosate. A biomarker approach was adopted to determine the impact of glyphosate, Spirulina and their mixture, during two time slots (4 and 7 days), on Mytilus galloprovincialis. Glyphosate treated mussels revealed significantly increased malondialdehyde and decreased acetylcholinesterase (AChE) levels. Spirulina normalized catalase (CAT), glutathione-S-transferase (GST), and AChE activities. Furthermore, it reduced glyphosate-induced malondialdehyde (MDA) levels. The current study suggests a protective effect of Spirulina against glyphosate-induced oxidative stress by strengthening the antioxidant system, sequestering ROS and inhibiting cellular damage.

Real-Time Detection of Glyphosate by a Water-Gated Organic Field-Effect Transistor with a Microfluidic Chamber

This paper reports the development of a real-time monitoring system utilizing the combination of a water-gated organic field-effect transistor (WG-OFET) and a microfluidic chamber for the detection of the herbicide glyphosate (GlyP). For the realization of the real-time sensing with the WG-OFET, the surface of a polymer semiconductor was utilized as a sensing unit. The aqueous solution including the target analyte, which is employed as a gate dielectric of the WG-OFET, flows into a designed microfluidic chamber on the semiconductor layer and the gate electrode. As the sensing mechanism, the WG-OFET-based sensor utilizes the competitive complexation among carboxylate-functionalized polythiophene, a copper(II) (Cu²⁺) ion, and GlyP. The reversible accumulation and desorption of the positively charged Cu²⁺ ion on the semiconductor surface induced a change in the electrical double-layer capacitance (EDLC). The optimization of the microfluidic chamber enables a uniform water flow and contributes to real-time quantitative sensing of GlyP at a micromolar level. Thus, this study would lead to practical real-time sensing in water for various fields including environmental assessment.

Bisphenol A induced toxicity in blood cells of freshwater fish Channa punctatus after acute exposure

The widespread use of bisphenol A (BPA) has led to its ubiquity in the natural environment. It is extensively incorporated into different industrial products and is associated with deleterious health effects on both public and wildlife. The current trial was conducted to determine the toxic potential of bisphenol A using various parameters viz haematological, biochemical, and cytological in freshwater fish Channa punctatus. For this purpose, fish were exposed to 1.81 mg/l (1/4 of LC₅₀) and 3.81 mg/l (1/2 of LC₅₀) of BPA along with positive (acetone) and negative controls (water) for 96 h. The blood samples were collected at 24, 48, 72, and 96 h post-exposure. Compared to the control group, fish after acute exposure to BPA showed a significant decrease in HB content, number of red blood cells, PCV values whereas a significant increase in WBCs count was recorded with an increase in the exposure period. Besides, oxidative stress (determined as malondialdehyde content) increased as BPA concentration increased. Further, the activity of different antioxidant enzymes like catalase, and superoxide dismutase decreased significantly after treatment. Results also showed significantly increased frequency of morphological alterations, nuclear changes, and increased DNA damage potential of BPA in red blood cells. Further structural analysis of erythrocytes in maximally damaged group using Scanning Electron Microscopy was performed. The study concludes that BPA exhibits genotoxic activity and oxidative stress could be one of the mechanisms leading to genetic toxicity.

Multixenobiotic resistance mechanism: Organ-specific characteristics in the fish Prochilodus lineatus and its role as a protection against genotoxic agents

The multixenobiotic resistance mechanism (MXR) can decrease intracellular genotoxic pressure through the efflux of compounds out of the cell. Thus, this work presents a temporal approach to evaluate the MXR activity and the occurrence of genotoxic damage in different organs of the fish Prochilodus lineatus after an intraperitoneal injection of benzo[a]pyrene (B[a]P). Although the liver and brain demonstrated rapid MXR induction (6 h), the occurrence of DNA damage was not prevented. However, these organs presented some return to DNA integrity after MXR activity. The kidney demonstrated the slowest response in the MXR induction (24 h), which may be related to the preferential excretion of B[a]P metabolites by this route. Moreover, the kidney MXR reduction at 96 h may be related to its role in the excretion of metabolites from all other metabolizing organs. The gills did not appear to play an essential role in xenobiotics efflux; however, their participation in biotransformation is exhibited through the occurrence of DNA damage. The integrated response of the organs in the dynamics for the maintenance of the organism integrity could be promoted by the circulation of the xenobiotic through the bloodstream, which corroborates the increase in the DNA damage in the erythrocytes at 6 h. Therefore, the ability to induce MXR was linked to the preservation of DNA integrity in the presence of B[a]P, since MXR acts to avoid the accumulation of xenobiotics inside the cell.

Naphthalene-2-sulfonate induced toxicity in blood cells of freshwater fish Channa punctatus using comet assay, micronucleus assay and ATIR-FTIR approach

Present inquisition was undertaken to evaluate the genotoxicity of naphthalene-2-sulfonate (2NS), a sulfonated aromatic compound and a momentous intermediate involved in the synthesis of dyes and surfactants, in fresh water fish, Channa punctatus. After LC₅₀ determination, two sublethal concentrations i.e. 2.38 g/15 g b.w. (1/4 of LC₅₀) and 4.77 g/15 g b.w. (1/2 of LC₅₀) were selected for studying acute exposure. For evaluating sub chronic exposure 1/10th (0.238 g/L) and 1/20th (0.119 g/L) of safe application rate (SAR) were reckoned. Blood samples were collected after 24, 48, 72, and 96 h exposure period to study acute effect, and after 30 and 60 days exposure period for sub-chronic effect. Symbolic elevation in time and dose dependent DNA damage was observed by comet assay as well as micronucleus test revealing maximum damage after 60 days of exposure. After cessation of exposure to 2NS, evident recovery was observed after 30 days. Along with comet assay and micronucleus test, spectroscopic evaluation of DNA damage was also noted using Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR). The biomolecular range (800 cm^-1 - 1800cm-¹) in lyophilized red blood cell's extracted from 60 days exposed as well as control group exhibit significant alterations in their nucleic acid indicated through multivariate analysis i.e. Principal Component Analysis (PCA). Further structural analysis of erythrocytes in maximally damaged group using Scanning Electron Microscopy was performed. Thus the study proposed the genotoxic impact of 2NS which is further supported by other toxicity markers like ATR-FTIR and Scanning Electron Microscopy.

Glyphosate-induced lipid metabolism disorder contributes to hepatotoxicity in juvenile common carp

Residues of glyphosate (GLY) are widely detected in aquatic systems, raising potential environmental threats and public health concerns, but the mechanism underlying GLY-induced hepatotoxicity in fish has not been fully elucidated yet. This study was designed to explore the hepatotoxic mechanism using juvenile common carp exposed to GLY for 45 d, and plasma and liver samples were collected at 15 d, 30 d, and 45 d to analyze the assays. First, GLY-induced hepatic damage was confirmed by serum liver damage biomarker and hepatic histopathological analysis. Next, changes in oxidative stress biomarkers, gene expression levels of pro- and anti-inflammatory cytokines, and lipid metabolism-related parameters in collected samples were analyzed to clarify their roles in GLY-induced hepatic damage. Data showed that oxidative stress was an early event during GLY exposure, followed by hepatic inflammatory response. Lipid metabolism disorder was a late event during GLY exposure, as evidenced by overproduced hepatic free fatty acids, enhanced lipogenesis-related gene expression levels, reduced lipolysis-related gene expression levels, and resultant hepatic lipid accumulation. Collectively, these findings demonstrate that GLY induces hepatotoxicity in fish through involvement of oxidative stress, inflammatory response, and lipid metabolism disorder, which are intimately interrelated with each other during GLY exposure.

Genotoxic effects of glyphosate on Physalaemus tadpoles

Genotoxicity studies have revealed that pesticides bind to genetic material in non-target vertebrates, thereby impairing the genetic integrity of these animals. The main objective of this study was to determine the genotoxic damage in erythrocytes of two native South American amphibian Physalaemus cuvieri and Physalaemus gracilis, both species exposed to a glyphosate-based herbicide. We evaluated the presence of micronuclei (MN) and erythrocyte nuclear abnormalities (ENA) as biomarkers for potential genotoxic compounds. Tadpoles were exposed to doses permitted by Brazilian legislation and concentrations found naturally in Brazilian and Argentinian waters (500, 700 and 1000 μg/L). Glyphosate-based herbicide caused micronuclei formation and several types of erythrocyte nuclear abnormalities in both Physalaemus species. The total frequency of MN and ENA demonstrated the occurrence of cell damage at all tested concentrations. Glyphosate herbicide can be considered a genotoxic that may impact the genetic integrity of native populations of P. cuvieri and P. gracilis.

Co-exposure of iron oxide nanoparticles and glyphosate-based herbicide induces DNA damage and mutagenic effects in the guppy (Poecilia reticulata)

Iron oxide nanoparticles (IONPs) have been tested to remediate aquatic environments polluted by chemicals, such as pesticides. However, their interactive effects on aquatic organisms remain unknown. This study aimed to investigate the genotoxicity and mutagenicity of co-exposure of IONPs (γ-Fe2O3 NPs) and glyphosate-based herbicide (GBH) in the fish Poecilia reticulata. Thus, fish were exposed to citrate-functionalized γ-Fe2O3 NPs (0.3 mg L-1; 5.44 nm) alone or co-exposed to γ-Fe2O3 NPs (0.3 mg L-1) and GBH (65 and 130 μg of glyphosate L-1) during 14 and 21 days. The genotoxicity (DNA damage) was analyzed by comet assay, while the mutagenicity evaluated by micronucleus test (MN test) and erythrocyte nuclear abnormalities (ENA) frequency. The co-exposure induced clastogenic (DNA damage) and aneugenic (nuclear alterations) effects on guppies in a time-dependent pattern. Fish co-exposed to NPs and GBH (130 μg glyphosate L-1) showed high DNA damage when compared to NPs alone and control group, indicating synergic effects after 21 days of exposure. However, mutagenic effects (ENA) were observed in the exposure groups after 14 and 21 days. Results showed the potential genotoxic and mutagenic effects of maghemite NPs and GBH co-exposure to freshwater fish. The transformation and interaction of iron oxide nanoparticles with other pollutants, as herbicides, in the aquatic systems are critical factors in the environmental risk assessment of metal-based NPs.

Effects on Ultrastructure, Composition and Specific Surface Area of the Gills of Odontesthes bonariensis Under Subchronic Glyphosate-Based Herbicide Exposure

Gills represent one of the major sites of gas exchange of fish, consequently they are in continuous close contact with the aquatic environment and its pollutants. In the present study the effects on gills of pejerrey fish, Odontesthes bonariensis, under glyphosate-based herbicide subchronic exposure were analyzed. Adult animals were exposed to sublethal concentrations of a glyphosate-based commercial formulation (1 and 10 PMG mg L-1, PMG: glyphosate active ingredient) for 15 days, while control group was maintained in rearing water. Ultrastructural changes in gills were observed by scanning electron microscopy (SEM). The composition of the surface epithelium and specific surface area were determined by energy dispersive spectroscopy (EDS) and N2 (g) adsorption-desorption isotherms, respectively. The herbicide exposure induced severe alterations in gill ultrastructure, as shown in the SEM micrographs. Accordingly, an increase in surface area of the gills of exposed animals was determined. These results support that gills parameters of freshwater fish are sensitive morphological biomarkers for glyphosate exposure.

Heavy metal bioaccumulation, oxidative stress and genotoxicity in African catfish Clarias gariepinus from Orontes river

One of the major problems affecting the ecosystem health is the exposure of heavy metals due to anthropogenic activities. These exposures may induce toxiogenetic damage and carcinogenesis in aquatic organism. DNA damage biomarkers for fish species detect genotoxic parameters for ecological risk assessment. In the present study, the effect of heavy metals (Cr, Cd, Cu, Fe and Mn) on DNA damage and oxidative stress of Clarias gariepinus was examined by Comet assay at Reference site and two different sampling sites of the Orontes River. Moreover, the relationship between DNA damage and physiological response to oxidative stress caused in C. gariepinus was investigated by sampling seasonal water and fish samples for one year. In this study, Cr, Cd and Cu in water column of Orontes River and the concentrations of Fe and Mn in liver tissue of C. gariepinus were highly exceed the maximum permissible limit set by EPA (1999, 2016) WHO (1989) and TEG (2012) that can cause adverse effects on environment health. SOD activities in liver tissues were significantly higher than those in muscle tissues. SOD, CAT activity and MDA levels of both Site 1 and Site 2 at Orontes River were higher than those of the Reference site. In result of the COMET analysis, the highest levels of DNA damage were found at gill and liver tissues in Site 2 (17.746 ± 1.072% T-DNA; 16.014 ± 0.710% T-DNA respectively) at Orontes river. A higher level of DNA damage in gill cells compared to liver cells was observed in all regions of the Orontes River. In Principal component analysis (PCA), the heavy metals Cd, Cr and Cu (in the water column) and MDA in liver and muscle revealed strong contribution to the observed DNA damage that were scattered opposite to each other's along the principal components. Moreover, correlations between parameters revealed a positive significant relationship between Cd, Cr and Cu in water and DNA damage levels in C. gariepinus. Pearson correlation analysis detected a positive relationship between MDA, CAT and SOD and DNA damage levels in African catfish. Consequently, this study exposed genotoxic damage and oxidative stress of C. gariepinus due to metal pollution in Orontes River and lead to the better understanding of genotoxicty, oxidative stress and heavy metal relationships.

A micronucleus assay detects genotoxic effects of herbicide exposure in a protected butterfly species

Lycaena dispar Hawort (Lepidoptera: Lycaenidae), a protected butterfly, is declining in Europe, but it thrives in rice fields in northern Italy. Here, agrochemical usage could threaten its long-term survival. We investigated, by micronucleus (MN) assay, the genotoxic effect of glyphosate, a common herbicide, on L. dispar larvae. Micronuclei (MNi) are DNA fragments separated from the main nucleus and represent the result of genomic damage that has been transmitted to daughter cells. In a control/treatment experiment, we extracted epithelial cells from last-instar larvae fed with Rumex spp. plants sprayed with a solution containing 3.6 g/L of glyphosate, and from larvae fed with unsprayed plants. MNi and other chromosomal aberrations-nuclear buds (NBUDs) and bi-nucleated cells-were then scored in 1000 cells/subject. Significant differences were found between glyphosate-exposed and control groups in terms of MNi and total genomic damage, but not in terms of NBUDs or bi-nucleated cells. We reported a possible genomic damage induced by glyphosate on larvae of L. dispar. For the first time, a MN assay was used in order to evaluate the genomic damage on a phytophagous invertebrate at the larval stage. Increased levels of MNi reflect a condition of genomic instability that can result in reduced vitality and in an increased risk of local extinction. Therefore, farmland management compatible with wildlife conservation is needed.

Effect of heavy metals on toxicogenetic damage of European eels Anguilla anguilla

Aquatic organisms are exposed to a variety of contaminants such as heavy metals introduced into the environment as a consequence of anthropogenic activities that usually cause genotoxic damage in aquatic organisms. DNA damage biomarkers for fish species detect genotoxic parameters for ecological risk assessment. In the present study, the effect of heavy metals (Cd, Cr, Cu, Fe, Ni, Pb, Zn, Co, and Mn) on DNA damage of Anguilla anguilla was examined by comet assay at reference site and three different sampling sites of the Orontes River. The relative mean heavy metal concentrations in water column were in the order of Fe>Cr>Pb>Zn>Ni>Cu>Mn>Cd>Co in all the sampling sites. Cr, Cd, and Pb concentrations at all sampling sites were above the values allowed by the EPA (1999, 2016). With these results, negative effects of Cr, Cd, and Pb appeared on ecosystem health. The comet assay showed a higher level of DNA damage in the gill cells in comparison with the liver cells of A. anguilla. The highest level of DNA damage as %T-DNA, tail moment, and tail migration in gill cells were 20.007 ± 1.744 %; 2.899 ± 0.341 μm, and 12.383 ± 01.040 TM_i and 20.172 ± 1.944 %, 2.559 ± 0.265 μm, and 10.763 ± 0.910 TM_i at Site 2 and Site 3, respectively. The correlations between heavy metals and DNA damage parameters revealed that both Cu and Co in water showed significant negative correlations (p < 0.05) with DNA damage levels. Consequently, this study revealed the genotoxic damage of A. anguilla due to pollution in Orontes River and lead to the better understanding of genotoxicity and heavy metal relationships.

Determination of the Ecotoxicity of Herbicides Roundup® Classic Pro and Garlon New in Aquatic and Terrestrial Environments

Herbicides help increase agricultural yields significantly, but they may negatively impact the life of non-target organisms. Modifying the life cycle of primary producers can affect other organisms in the food chain, and consequently in the whole ecosystem. We investigated the effect of common herbicides Roundup® Classic Pro (active substance glyphosate) and Garlon New (triclopyr and fluroxypyr) on aquatic organisms duckweed Lemna minor and green algae Desmodesmus subspicatus, and on the enzymatic activity of soil. We also compared the effects of Roundup® Classic Pro to that of a metabolite of its active substance, aminomethylphosphonic acid (AMPA). The results of an algal growth test showed that AMPA has a 1.5× weaker inhibitory effect on the growth of D. subspicatus than the Roundup formula, and the strongest growth inhibition was caused by Garlon New (IC50Roundup = 267.3 µg/L, IC50Garlon = 21.0 µg/L, IC50AMPA = 117.8 mg/L). The results of the duckweed growth inhibition test revealed that Roundup and Garlon New caused 100% growth inhibition of L. minor even at significantly lower concentrations than the ready-to-use concentration. The total chlorophyll content in the fronds was lowest when Garlon New was used. The highest dehydrogenase activity was observed in soil treated with Garlon New, and the lowest in soil treated with Roundup® Classic Pro. The results of this study showed that all three tested substances were ecotoxic to the tested organisms.

Ru(II)-Based Amino Acid Complexes Show Promise for Leukemia Treatment: Cytotoxicity and Some Light on their Mechanism of Action

Ruthenium is attracting considerable interest as the basis for new compounds to treat diseases, and studies have shown that complexes with different structures have significant antineoplastic and antimetastatic potential against several types of tumors, including tumors resistant to cisplatin drugs. We examined the cytotoxic, genotoxic, and pro-apoptotic activities of six ruthenium complexes containing amino acid with general formulation [Ru(AA)(bipy)(dppb)]PF₆, where AA = amino acid (alanine, glycine, leucine, lysine, methionine, or tryptophan); bipy = 2,2´-bipyridine; and dppb = [1,4-bis(diphenylphosphine)butane], against A549 (lung carcinoma) and K562 (chronic myelogenous leukemia) cancer cells. The results show that the ruthenium complexes tested were able to induce cytotoxicity in A549 and K562 cancer cells. Complex 1 containing alanine inhibited the cell viability of A549 and K562 tumor cells by inducing apoptosis, as evidenced by an increased number of Annexin V-positive cells and the induction of DNA damage and cell cycle arrest. Complex 1 was able to induce caspase-mediated apoptosis in K562 cells through the mitochondrial dysfunction, the upregulation of apoptotic genes, and the downregulation of Bcl2 anti-apoptotic gene. Besides being cytotoxic to K562 and A549 cells, ruthenium complex containing alanine shows low cytotoxicity and genotoxicity against non-tumor cells. These results suggest that the ruthenium (II) complex is a potential safe and efficient antineoplastic candidate for leukemia treatment.

Lethal and sublethal exposure of Hemichromis bimaculatus (Gill, 1862) to malachite green and possible implications for ornamental fish

Malachite green (MG) is a triphenylmethane dye that is widely used in aquaculture as a fungicide, bactericide, ectoparasiticide, and antiprotozoal. There is great debate regarding the potential for this compound to trigger adverse effects. Here, we review the previous findings and then evaluate the lethal and sublethal effects of MG in the species Hemichromis bimaculatus (jewelfish). The lethal concentration for 50% of the fish in 96 h was 1 mg/L. We observed a dose-dependent increase in the percentage of fish mortality as well as physical and behavioral changes. We further found that the highest tested sublethal dose significantly increased the DNA damage index identified using the comet assay (74.97 ± 13.8 at a significant level of P < 0.05 for the 0.75 mg/L concentration), but did not significantly alter the results of the micronucleus test. Although our results suggest that MG confers risks on exposed fish, the findings were significant only at the highest exposure concentration (0.75 mg/L). At lower concentrations (0.25 mg/L and 0.5 mg/L), no adverse effect was observed. The maximum MG concentration recommended for use in ornamental fish farming is 0.2 mg/L. Therefore, our results suggest that, specifically for the parameters analyzed in this work, MG does not have any adverse effect when users strictly adhere to the recommended concentration criteria for ornamental fish.

Interference of goethite in the effects of glyphosate and Roundup® on ZFL cell line

Goethite (α-FeOOH) brings important perspectives in environmental remediation, as, due to its physicochemical properties, this iron oxide can adsorb a wide variety of compounds, including glyphosate. This study aimed to evaluate the effects of goethite nanoparticles (NPs), glyphosate (Gly), Roundup® (Rd), and co-exposures (Gly + NPs and Rd + NPs) on zebrafish liver cell line (ZFL). ZFL cells were exposed to NPs (1, 10, and 100 mg L-1), Gly (3.6 mg L-1), Rd (10 mg L-1), and co-exposures (Gly + NPs and Rd + NPs), or only to saline for 1, 6, and 12 h. Cell viability was assessed by Trypan blue, MTT, and neutral red assays. The generation of reactive oxygen species and total antioxidant capacity were also determined, while genotoxicity was quantified by the comet assay. Both NPs and Rd in isolation produced cytotoxic effects at 6 h and genotoxic effects at 1 and 6 h. Rd + NPs resulted in synergistic effects, intensifying the toxicity. Cells exposed to Gly did not present toxic effects and Gly + NPs resulted in the suppression of toxic effects observed for NPs. The presence of other components in Roundup® seems to favor its toxicity compared to the active ingredient. In conclusion, according to the in vitro model, the concentrations used were not safe for the ZFL lineage.

Bioaccumulation and toxicity of 2-naphthalene sulfonate: an intermediate compound used in textile industry

The aromatic compounds substituted with sulfonate groups, being xenobiotic, resist biodegradation in the environment and tend to accumulate up to toxic levels. The hydrophilic sulfonated group makes these compounds highly water soluble and they tend to pass through water-treatment plants. The release of untreated effluents from these industries results in pollution of water bodies affecting aquatic fauna. Thus, the toxicity regarding these compounds is of major concern. The 2-naphthalene sulfonate is a sulfonated aromatic compound being widely used in textile industries. Being non-biodegradable concern regarding its toxicity has risen. Thus in the light of above facts, the present study was undertaken to determine the toxicity of 2-naphthalene sulfonate in blood cells of Channa punctatus. For this, LD₅₀ was determined and after selection of sublethal doses oxidative stress, genotoxicity and bioaccumulation were studied. For oxidative stress determination, biochemical markers such as malondialdehyde content and activities of superoxide dismutase, catalase, and glutathione-S-transferase were studied. Genotoxicity was studied using comet and micronucleus assay. Significant increase in oxidative stress and DNA damage in the exposed groups as compared to control group (P ≤ 0.05) was observed till 96 h. However, decreased values of all the studied parameters at 720 h (30 days) indicate repair capacity of fish. Further, the bio accumulative potential of 2-naphthalene sulfonate was assessed in blood plasma using high-performance liquid chromatography. The study revealed the toxic potential of 2-naphthalene sulfonate to aquatic organisms thus stressed on the need for the implementation of stringent policies regarding the management of such toxic compounds.

Genotoxicity of mixtures of glyphosate with 2,4-dichlorophenoxyacetic acid chemical forms towards Cnesterodon decemmaculatus (Pisces, Poeciliidae)

Acute genotoxicity of commercial glyphosate (GLY) (Credit®)-, 2,4-D-acid (2,4-D) (Dedalo Elite)-, 2,4-D-amine (2,4-D DMA) (Weedar Full®)- and 2,4-D-ester (2,4-D BE) (Herbifen Super®)-based herbicide formulations alone and their combinations were analysed in Cnesterodon decemmaculatus. Mortality was evaluated as a lethal end-point and the single cell gel electrophoresis (SCGE) bioassay was used as a sublethal end-point. LC5096h values for Dedalo Elite was 0.46 mg/L and Herbifen Super® was 2.67 mg/L based on 2,4-D and 2,4-D BE, respectively. Results reveal a higher toxicity exerted on C. decemmaculatus after exposure to 2,4-D- rather than 2,4-D BE-based herbicide formulations. Overall, results demonstrated an enhancement in the genetic damage index committed to an enhancement of damaged erythrocytes of C. decemmaculatus when exposed to Credit®, Dedalo Elite, Weedar Full® and Herbifen Super® at 5% and 10% of LC5096h values alone as well as in their combinations. Overall, the combination of GLY plus 2,4-D or GLY plus 2,4-D DMA showed a synergistic pattern whereas the combination of GLY plus 2,4-D BE was antagonic. Furthermore, this research is pioneer in the assessment of lethality and genotoxicity induced by 2,4-D-, 2,4-D DMA- and 2,4-D BE-based formulations when combined with GLY-based formulated herbicides in fish after they are acutely exposed.

Microplastics and copper effects on the neotropical teleost Prochilodus lineatus: Is there any interaction?

Microplastics (MP) are emerging contaminants widely found in aquatic ecosystems. In addition to MP toxicity itself, there is increasing concern about the MP adsorption capacity and the interactive effects with other contaminants, such as copper. The objective of this research was to investigate the effects of polyethylene microplastic and its association with copper (Cu) in genotoxic, biochemical, and physiological biomarkers of the neotropical teleost Prochilodus lineatus. Fish were exposed for 24 and 96 h to MP (20 μg L^-1) and Cu (10 μg L^-1) and MP + Cu. The results showed that MP and Cu, both isolated and in combination, promoted DNA damage in erythrocytes (96 h) and liver cells (24 and 96 h) indicating that MP and Cu are genotoxic. Fish exposed only to Cu (96 h) showed a decrease in lipid peroxidation in the liver despite of the decrease in glutathione content, indicating the efficiency of other antioxidant defenses. Brain acetylcholinesterase was inhibited in the animals from all the treatments. Although MP did not influence on Cu accumulation in tissues, decreased plasma Na⁺ and Ca²⁺ (24 h) occurred after the exposure to MP and Cu, isolated and combined. Exposure to MP and MP + Cu resulted in decreased activity of Ca²⁺-ATPase (24 h). Taken altogether, these results showed that MP and Cu depicted genotoxic, neurotoxic, and physiological effects on P. lineatus, both alone and combined. An interaction between Cu and MP was observed in plasma Ca²⁺, where the combination of both contaminants caused a greater effect than the contaminants alone.

Avermectin induces the oxidative stress, genotoxicity, and immunological responses in the Chinese Mitten Crab, Eriocheir sinensis

Avermectin is commonly used in aquaculture systems for pest control in recent decades in China. However, no information is provided for the toxic effect to the important commercial species, Chinese mitten crab, Eriocheir sinensis. To investigate the aquatic toxicity of avermectin, an acute toxic test was performed in this study. The results showed that the 48 h- and 96 h- LC₅₀ were 1.663 and 0.954 mg/L, respectively. For further research, crabs were exposed to sublethal concentrations of 0.03, 0.06, 0.12, 0.24 and 0.48 mg/L. Levels of antioxidants, including superoxide dismutase (SOD), catalase (CAT) and total antioxidant capacity (T-AOC) were significantly (P<0.05) decreased with dose- and time- dependent responses, meanwhile the oxidative products including malondialdehyde (MDA), hydrogen peroxide (H₂O₂) and protein carbonyl in serum increased significantly (P<0.05) at concentrations of 0.24 and 0.48 mg/L throughout the experiment. A significant (P<0.05) increase of intracellular ROS and decrease of phagocytic activity was observed in high concentration groups, with dose- and time- dependent manners during the exposure. In addition, serious genetic damage was detected, for the significant increase (P<0.05) of both comet ratio and %DNA in tail at each concentration, and micronucleus (MN) frequency at concentrations of 0.12, 0.24 and 0.48 mg/L at 96 h. These results indicated that sublethal concentration exposure of avermectin had a prominent toxic effect on E. sinensis based on the oxidative stress induced by generated ROS, immunological activity inhibition and genotoxicity.

Effects of chronic glyphosate exposure to pregnant mice on hepatic lipid metabolism in offspring

Glyphosate is the active ingredient in Roundup, one of the most popular herbicides in the world, and its toxicity has caused increasing concerns. The present study aims to investigate the toxic effects of prenatal exposure to pure glyphosate or Roundup on lipid metabolism in offspring. During gestational days (GDs), ICR mice (from Institute of Cancer Research) were given distilled water, 0.5% glyphosate solution (w/v, 0.5 g/100 ml) or 0.5%-glyphosate Roundup solution orally. The livers and serum samples of the offspring were collected on gestational day 19 (GD19), postnatal day 7 (PND7) and PND21. The results showed a significant decrease in the body weight and obvious hepatic steatosis with excessive lipid droplet formation in offspring. Moreover, the concentrations of lipids such as triglycerides (TGs), total cholesterol (T-CHO), and low-density lipoprotein cholesterols (LDL-C) increased to a significant extent in both the serum and livers. Furthermore, there were significant differences in the expression levels of the genes SREBP1C, SREBP2, Fasn, Hmgcr, Hmgcs and PPARα, which are related to lipid biosynthesis or catabolism in the liver. These results demonstrate that chronic prenatal exposure to glyphosate can result in lipid metabolism disruption in the offspring of mice, as glyphosate exerts a negative influence on the expression of lipogenesis genes.

Chitosan/glyphosate formulation as a potential, environmental friendly herbicide with prolonged activity

Although there are many reports on the dangers posed by glyphosate, this herbicide is still one of the most popular and widely used total weed killers. Therefore, great effort should be made to minimize exposure to this herbicide and limit its losses into the environment. The aim of this study was to prepare a new formulation consisted of various molecular weight chitosans with glyphosate and their evaluation toward active substance release, phytotoxicity, and preliminary herbicidal efficiency. The phytotoxicity study of the obtained chitosan/glyphosate formulations was determined based on the Organisation for Economic Co-operation and Development 208 guideline. Among all tested formulations evaluated for phytotoxicity, that containing the highest molecular weight of chitosan was found to be the least toxic, showing simultaneously the most effective herbicidal activity against selected weeds. The release rate of glyphosate from the obtained formulations was dependent on the molecular weight and viscosity of chitosan.