Micronuclei and chromatid buds are the result of related genotoxic events

Impacts of horticultural environments on Rhinella arenarum (Anura, Bufonidae) populations: exploring genocytotoxic damage and demographic life history traits

Horticulture poses a significant ecological risk, as agrochemicals are applied more frequently and in larger quantities per unit of production compared to extensive crop fields. The native amphibian Rhinella arenarum serves as a reliable bioindicator of environmental health. This study aimed to assess genocytotoxic damage and demographic life history traits of R. arenarum inhabiting horticultural environments. Sampling was conducted in suburban sites in central Argentina: H1 and H2 (sites associated with horticultural activity) and a reference site, RS. Environmental parameters were recorded, and the frequency of micronuclei (Mn), nuclear abnormalities (ENA), and indicators of cytotoxic damage were determined in tadpoles and adults. Demographic variables (age at maturity, longevity, potential reproductive lifespan, size at maturity, modal lifespan) were calculated. The highest nitrate and phosphate values, along with low dissolved oxygen values, were recorded at sites H1 and H2. Organisms inhabiting horticultural environments exhibited higher frequencies of Mn and ENA, surpassing those recorded in previous studies on tadpoles from sites with extensive crop production. Size at maturity and age at maturity of females, as well as size at maturity, longevity, mean age, and mean adult SVL of males, were lower in horticultural sites. The results support the hypothesis that anuran populations inhabiting horticultural environments demonstrate a diminished health status attributed to subpar environmental quality. Monitoring endpoints at different biological levels provides information on the ecotoxicological risk for amphibians and human populations inhabiting nearby areas.

Effect on growth and development of common toad (Rhinella arenarum) tadpoles in environment related to fluorite mine

Fluorite mining activities have been scarcely evaluated so far and the potential effect of this activity on larval stages is poorly known. Thus, studies addressing the effect of contaminants present in water bodies on the health of amphibian larvae are crucial information for their conservation and constitute a warning sign of environmental modification. This study aims to evaluate the effects of natural and artificial surface waters associated with a fluorite mine on the early life stages of Rhinella arenarum. Using microcosms, we assessed four sites with different degrees of disturbance by the fluorine mine: Vallecitos stream (undisturbed); Cerros Negros upstream of mining camp (low disturbance); Cerros Negro downstream of mining camp (medium disturbance); Decantation Ponds (high disturbance). For 65 days we measured different endpoints at different periods of tadpole development. The highest mortality of tadpoles was observed in the Decantation Ponds. In the same way, larval body condition was lower at Decantation Ponds throughout the study, due mainly to the lower weight. A significant decrease in growth and development was observed in Cerros Negro downstream of the mining camp and Decantation Ponds. No significant differences in growth, development and mortality were observed for the other two sites. At the metamorphic climax we observe a lower body condition and a reduced recruitment of individuals in Decantation Ponds. This study allowed us to assess the effect on larvae of R. arenarum of fluorite mining wastewater compared with other near-natural sites. Given the potentially negative synergic effects of mixed water pollutants on tadpoles, this study suggests that chronic exposure to fluorite mining water may significantly impact the adult amphibian population structure, thus altering population viability. Therefore, we propose to monitor the correct functioning of the mine and especially of Decantation Ponds to avoid discharges into the natural streams.

Effect of environmental factors on blood counts of Gambusia affinis caught at Brantas River watershed, Indonesia

Background: Contamination of freshwater ecosystems has become a major issue as it threatens public water sources as well as aquatic life. It is important to predict changes in organism health, given a known number of environmental factors and pollutant concentrations, in order to better manage contaminants through biomarker analysis. This study aims to examine the ecosystem health of the Brantas River based on its environmental condition and the hematology profile of Gambusia affinis fish present in the river. This species was chosen because of its wide distribution along the Brantas River, and because it is very tolerant, adaptable, highly abundant, and easy to catch.

Methods: The study area included 10 sampling sites along the Brantas River watershed. In total, six water quality parameters were observed (temperature, pH, dissolved oxygen (DO), biological oxygen demand (BOD), ammonia concentration, and phenol concentration) and hematology measurements consisted of erythrocyte, leucocyte, and micronuclei analyses.

Results: The results showed that the upstream area of Brantas River, located in Batu, was the least polluted region, while Mojokerto was the most polluted. The erythrocyte level of Gambusia affinis caught in most sampling sites was quite low. Furthermore, research revealed that the status of Gambusia affinis' hematological profile was significantly correlated (p<0.05) with water quality parameters, particularly DO, BOD, ammonia, and phenol.

Conclusions: It can be concluded from these results that the hematological profile of the fish is poor due to high levels of organic waste and harmful substances.

Mitochondrial dysfunction in mandibular hypoplasia, deafness and progeroid features with concomitant lipodystrophy (MDPL) patients

Mandibular hypoplasia, Deafness and Progeroid features with concomitant Lipodystrophy is a rare, genetic, premature aging disease named MDPL Syndrome, due to almost always a de novo variant in POLD1 gene, encoding the DNA polymerase δ. In previous in vitro studies, we have already described several hallmarks of aging, including genetic damage, telomere shortening, cell senescence and proliferation defects. Since a clear connection has been reported between telomere shortening and mitochondria malfunction to initiate the aging process, we explored the role that mitochondrial metabolism and activity play in pathogenesis of MDPL Syndrome, an aspect that has not been addressed yet. We thus evaluated mtDNA copy number, assessing a significant decrease in mutated cells.

The expression level of genes related to mitochondrial biogenesis and activity also revealed a significant reduction, highlighting a mitochondrial dysfunction in MDPL cells. Even the expression levels of mitochondrial marker SOD2, as assessed by immunofluorescence, were reduced. The decrease in this antioxidant enzyme correlated with increased production of mitochondrial ROS in MDPL cells, compared to WT. Consistent with these data, Focused Ion Beam/Scanning Electron Microscopy (FIB/SEM) analysis revealed in MDPL cells fewer mitochondria, which also displayed morphological abnormalities. Accordingly, we detected autophagic vacuoles containing partially digested mitochondria.

Overall, our results demonstrate a dramatic impairment of mitochondrial biogenesis and activity in MDPL Syndrome. Administration of Metformin, though unable to restore mitochondrial impairment, proved efficient in rescuing nuclear abnormalities, suggesting its use to specifically ameliorate the premature aging phenotype.

Micronuclei and Nuclear Buds Induced by Cyclophosphamide in Crocodylus moreletii as Useful Biomarkers in Aquatic Environments

Simple Summary

Crocodiles are territorial reptiles that are exposed to both aquatic and terrestrial environments. Analyzing their state of health and the environment in which they live is essential to detect changes that could affect them by exposure to agents that damage their genetic material, putting their health or other species that share said habitat, including humans, at risk. There are several ways to determine exposure to harmful agents, a very simple and direct one is to analyze the nuclei of blood cells under a microscope, a test that can also be carried out directly in their habitat and that gives rapid results on the effects of agents on those at that moment they are exposed. This study demonstrates the possibility of analyzing the blood of Crocodylus moreletii to quickly analyze its exposure to toxic agents in a sample of its blood by evaluating two abnormal structures in its cells under the microscope, demonstrating that evidence of damage can be observed only by analyzing a drop of their blood.

Abstract

Micronuclei (MN) are used to assess genotoxic exposure, whereas nuclear buds (NBs) have been linked to genotoxic events. Crocodylus moreletii was studied to identify MN and NBs. Three groups were formed: Group 1 (water) and groups 2 and 3 (7 or 10 mg/kg of cyclophosphamide). A drop of blood was obtained daily from the claw tip at 0 to 120 h. Spontaneous micronucleated erythrocytes (MNEs) and erythrocytes with nuclear buds (NBEs) were counted. The frequencies of micronucleated young erythrocytes (MNYEs) and NB young erythrocytes (NBYEs) were evaluated, including the ratio of young erythrocytes (YE)/1000 total erythrocytes. No significant differences were observed in the YE proportion on sampling days; group 1 did not show differences for any parameter, whereas group 2 showed significant differences in MNEs and NBEs, and group 3 showed differences in NBEs and NBYEs. Some mitotic activity in circulation was observed in YEs. In conclusion, NBEs could be a more sensitive biomarker to genotoxic damage than MNEs. The identification of these biomarkers leads us to propose Crocodylus moreletii as a possible environment bioindicator because these parameters could be useful to analyze the in vivo health status of these reptiles and for biomonitoring genotoxic pollutants in their habitats.

Effect of Angiotensin-I Converting Enzyme Gene Insertion/Deletion Polymorphism on genome instability in children living in Russian Arctic

Main risks of arterial hypertension manifest in childhood. Children living in the Far North are especially susceptible to this. There is a need for an inexpensive, non-invasive and simple diagnosis of the risk of childhood pathologies. It was previously found that the genotype DD of the in/del polymorphic marker of the ACE gene is found in people at risk of developing cardiovascular pathologies. Buccal micronucleus cytome assay and genetic analysis were used in the work. In total, 77 schoolchildren from the city of Apatity, aged 15-17 years old, were examined. We have shown that carriers of the D allele have a tendency to an increase in the frequency of cells with micronuclei. In the case of homozygous I/I variant, the frequency of occurrence of cells with karyopycnosis is significantly higher than in carriers of allele D. Polymorphic marker in/del of the ACE gene is associated with apoptotic changes in the cells of the studied children. The in/del polymorphic marker of the ACE gene can be used as a prognostic marker of the processes of genome destabilization at the early stages of development of the human body.

Effect of Heracleum sosnowskyi extract aqueous solution on the Allium cepa root meristem

Heracleum sosnowskyi (Apiaceae) contains a lot of useful chemical ingredients that can be used in industry, medicine and other fields as plant component extracts and as chemical compounds that have been extracted in different ways, which requires the last to be tested for chemical safety, including a genotoxic test in vivo. In the present paper, the 96-hour effect of the H. sosnowskyi extract aqueous solution at concentrations of 0.01, 0.05, 0.10, and 0.50 mL/L on the genetic apparatus and mitotic activity of the cells of the Allium cepa (Alliaceae) root meristem is discussed. Distilled water was applied as a negative control, and hydrogen peroxide 1% as a positive one. The extract was prepared from the plant’s fresh leaves by soaking them in acetone. It was then distilled at 57 ºС and diluted with distilled water to obtain the experimental concentrations. As extract content in the aqueous solution increased, a statistically significant decrease in mitotic activity, an increase in aberrant cell percentage and a concentration-dependent inhibition of root growth were observed. In the 0.5 mL/L solution, if compared against the other experimental concentrations, an increase in the metaphase, anaphase and telophase indices along with a decrease in the prophase index were observed. The most common aberrations for all the concentrations were lagging and sticking chromosomes, anaphase bridges, ring chromosomes and nuclear buds. The same solution and the positive control produced membrane damage; giant and ghost cells. The results of the experiment performed have demonstrated the extract’s aneugenic effect that causes spindle disturbance, mitodepression and inhibits the cells of the Allium cepa root meristem, prevails over its clastogenic effect.

Toxicity of the sawdust used for phosphorus recovery in a eutrophic reservoir: experiments with Lactuca sativa and Allium cepa

Eutrophication is one of the environmental problems arising from the increase of essential nutrient concentrations, mainly phosphorus and nitrogen. In contrast to excess phosphorus, the depletion of phosphate rock deposits used for the production of fertilizers compromises the food supply. Therefore, the development of technologies that propose the recovery of the phosphorus contained in eutrophic environments for its later use for agricultural fertilization purposes is very important to ensure global food security. This work aimed to evaluate the toxic potential of the sawdust (biosorbent previously used for phosphorus adsorption) in order to enable its application in agriculture. For this, toxicity experiments with Lactuca sativa (lettuce) and Allium cepa (onion) seeds were performed. The phytotoxic potential was assessed by means of the seed germination index and physiological parameters such as radicle and hypocotyl growth. Cytotoxicity, genotoxicity, and mutagenicity tests were also performed on onion seeds. From statistical tests, it was possible to affirm that the sawdust did not promote inhibition of seed germination and radicle and hypocotyl growth. No genotoxicity, cytotoxicity and, mutagenicity were observed, which allowed to state that the sawdust is not toxic to the onion species, which reinforces the possibility of application of the biosorbent for soil fertilization purposes. Therefore, the use of sawdust for phosphorus biosorption with the subsequent agricultural application is promising and quite important from a global food security point of view.

Genotoxicity, oxidative stress, and biochemical biomarkers of exposure to green synthesized cadmium nanoparticles in Oreochromis niloticus (L.)

The considerable increment in the use of Nanoparticles in the industry has been recognized as an environmental concern today. Therefore, this study aimed to investigate the toxicity effects of green synthesized cadmium nanoparticles [Cd]^NPs using Moringa oleifera leaves extract on multi-biomarkers in Oreochromis niloticus after four weeks of exposure. The results showed that LC₅₀ values of [Cd]^NPs for 24, 48, 72 and 96 h were 2.17, 1.75, 1.49 and 1.22 mg l^-1, respectively. There was a significant decrease in the number of white and red blood cells, hemoglobin, hematocrit, mean corpuscular hemoglobin concentration value in fish exposed to [Cd]^NPs. The mean corpuscular volume and neutrophils were increased. [Cd]^NPs exposure to fish has led to cytotoxic and genotoxic changes in the erythrocytes. Significant changes were observed in the cortisol, triiodothyronine, and thyroxine levels of the fish exposed to [Cd]^NPs. The activities of aspartate aminotransferase and alanine aminotransferase increased. Glucose, total lipids, urea, and creatinine levels increased in the serum of fish exposed to [Cd]^NPs, whereas total protein contents and alkaline phosphatase activity decreased. A significant reduction was observed in glycogen, total antioxidant levels, and superoxide dismutase, catalase and glutathione S-transferase activities of fish exposed to [Cd]^NPs. In contrast, the [Cd]NPs exposure resulted in a significant increase in DNA fragmentation percentages, lipid peroxidation, and carbonyl protein levels in different tissues. The results of the present study confirmed that [Cd]^NPs has the toxicity potential to cause Cyto-genotoxicity, oxidative damages, changes in the hematological and biochemical changes, and endocrine disruptor in the fish.

Water assessment of the Itapemirim River/Espírito Santo (Brazil): abiotic and toxicogenetic aspects

The Itapemirim River is considered one of the most important water resources in the state of Espírito Santo, Brazil. However, environmental problems due to continuous anthropogenic contamination are threatening its potential use. This study assessed water quality by analyzing abiotic and toxicogenetic aspects of the water from four stations along the river. Samples were collected in both dry and rainy seasons. Most of the abiotic variables were below the threshold established by CONAMA Resolution No. 357/2005, and so were most of the metals. However, Al and Cu contents were above those allowed by legislation, ranging from 0.2 to 0.9 mg/L. Regarding toxicogenetic aspects, genotoxic effects were observed in meristematic cells of Allium cepa, in micronucleus test and comet assay of Oreochromis niloticus, and CHO-K1 cells. Mutagenic effects were significant at RI 02 (0.34), RI 03 (0.46), and RI 04 (0.12) stations on the first campaign in A. cepa F1 cells, compared to the negative control (0.0). The second campaign revealed the same results, but with the addition of samples from RI 01 (0.17) and RI 03 (0.18) showing mutagenicity in the micronucleus test with fish erythrocytes when compared to the negative control (0.3). Essentially, all the samples evaluated in both campaigns showed damage in A. cepa, O. niloticus, and CHO-K1 cells, thus demonstrating that the water quality of the Itapemirim River is compromised and requires action plans for its recovery.

Micronuclei in Fish Erythrocytes as Genotoxic Biomarkers of Water Pollution: An Overview

Freshwater and marine water bodies receive chemical contaminants from industrial, agricultural, urban, and domestic wastes. Eco-genotoxicity assays are useful tools to assess the cumulative genotoxicity of these pollutants. Fish are suitable indicators for biomonitoring of mutagenic and carcinogenic pollution.In this review, we present a complete overview of the studies performed so far using the micronucleus test in peripheral erythrocytes of fish exposed to polluted water. We have listed all the species of fish used and the geographical distribution of the investigations. We have analyzed and discussed all technical aspects of using this test in fish, as well as the advantages and disadvantages of the different experimental protocols. We have reported the results of all studies. This assay has become, for years, one of the simplest, fastest, and most cost-effective for assessing genotoxic risk in aquatic environments. However, there are still several factors influencing the variability of the results. Therefore, we have given indications and suggestions to achieve a standardization of experimental procedures and ensure uniformity of future investigations.

Genotoxic Consequences in Common Grass Carp (Ctenopharyngodon idella Valenciennes, 1844) Exposed to Selected Toxic Metals

The primary aim of the current study was to recognize the biomarker approach as the finest tool to identify the geno-toxicological effects of copper, chromium, and lead inside the blood of grass carp using micronucleus test and comet assay. The induced micronuclei frequency in response to the administered concentrations of LC50 metals was discovered in the erythrocytes of metal-exposed fish at four-time intervals. The genotoxic effect of these metals with respect to the formation of micronuclei was ranked as chromium > lead > copper. Percentages of other cellular and nuclear abnormalities were also determined in the exposed blood films. Equally, the genotoxic studies in terms of comet assay in fish blood revealed significant deviations p < 0.05 against each of the studied metal at their respective time interval as compared with the healthy fish group. However, induced frequency of micronuclei and the calculated DNA damage were not found to be duration dependent. Consequently, copper, chromium, and lead have been explored as cytotoxic elements that can be responsible for inducing genotoxic effects in fish existing aquatic habitats.

Effects of chronic exposure to microplastics of different polymer types on early life stages of sea trout Salmo trutta

The aim of the present study was to determine the effect of a long-term (113 days) exposure to microplastics on the development and induction of endocrine, geno- and cytotoxic responses in early life stages of sea trout Salmo trutta. Microplastic particles (3000 μm) of three most commonly mass-produced polymers (polystyrene - PS, polyethylene terephthalate - PET and polyethylene - PE) were applied in environmentally realistic concentrations (0.1% of sediment dry weight) in a laboratory experiment imitating the natural environment, typical for sea trout spawning grounds. The exposure of the sea trout, from fertilized eggs to mobile yolk-sac larvae, to microplastics did not affect the hatching success (the survival of embryos), hatching rate and the incubation period. Microplastics of any tested polymer type also had no adverse effect on the larvae survival, growth rate and the rate of yolk sack absorption. Similarly, no changes in frequencies of detected cytotoxicity endpoints compared to the control group were recorded. Exposure to polymer particles induced however the formation of genotoxicity endpoints (nuclear buds, micronuclei and blebbed nuclei cells). The level of total genotoxicity (ΣGentox) in fish larvae erythrocytes increased significantly in the following sequence: PS > PET > PE. No significant changes in the whole body corticosterone, dehydrocorticosterone and cortisone concentrations due to exposure to microplastics were recorded, while cortisol was detected in larvae exposed to PS. Our results show that long-term, non-ingestion related exposure to microplastics does not affect development of S. trutta early life stages but may lead to genotoxic responses. PS seems to be the most hazardous among all polymers studied. This is the first study demonstrating non-ingestion related toxicity of microplastics to the early life stages of fish.

Mutagenic, genotoxic and morphotoxic potential of different pesticides in the erythrocytes of Podocnemis expansa neonates

Despite the damaging effects of pesticides glyphosate (Gly), atrazine (Atra) and fipronil (Fip) on different organisms, the mutagenic, genotoxic and morphotoxic potential of testudine erythrocytes in freshwater remains unknown. Thus, the aim of the present study is to assess the toxicological potential of these compounds in Podocnemis expansa (Amazonian turtles) neonates from eggs artificially incubated in substrate at different concentrations of herbicides Gly and Atra and insecticide Fip. Micronucleus test and other nuclear abnormalities, as well as comet assay and morphometric measurements taken of models' circulating erythrocytes were used as toxicity biomarkers. Pups exposed to Gly (groups Gly-65 ppb and Gly-6500 ppb) were the ones recording the largest amount of nuclear abnormalities; erythrocytes with multilobulated, notched and displaced nucleus were mostly frequent in groups Atra-2 ppb and Gly -65 ppb. All treatments (Gly-6500 ppb, Atra-2 ppb, Atra-200 ppb, Fip-4 ppb and Fip-400 ppb), except for group Gly-65 ppb, led to decreased erythrocyte area, increased "nuclear area: erythrocyte area" ratio, as well as to decreased erythrocyte and erythrocyte nuclei circularity, which highlights the clear effect on the size and shape of these cells. On the other hand, the comet assay did not evidence any genotoxic effect caused by the assessed pesticides. This is a pioneer study on the mutagenic and morphotoxic potential of pesticides in P. expansa eclodides exposed in ovo to Gly, Atra and Fip; therefore, it is an insight on how these compounds can affect the health of these animals.

Assessing the seasonal and intrinsic variability of neurotoxic and cyto-genotoxic biomarkers in blood of free-living Eleonoras' falcons

In the present study we investigated seasonal and intrinsic variability of neurotoxic and cyto-genotoxic biomarkers in blood plasma and erythrocytes of free-living Eleonoras' falcons, captured during the pre-breeding (May of 2017 and 2018) and breeding period (September of 2017) on the Antikythira Island (Greece). Specifically, blood samples of captured birds were prepared for the determination of cholinesterase (ChEs, i.e. acetylcholinesterase/AChE and butyrylcholinesterase/ BChE) activity, as well as the formation of nuclear (i.e. the formation of micronuclei into the cells/MN, binucleated cells/BN and others), and cellular/cytoplasmic (i.e. echinocytes/EC, acanthocytes/AC and notched cells/NC) abnormalities in blood plasma and erythrocytes, respectively. Our results indicated that birds sampled in late May had higher ChE and BChE activity levels, as well as higher frequency of total nuclear abnormalities. The latter were also higher in second calendar year (2cy) birds. Cellular/cytoplasmic abnormalities were less frequent in falcons having better body condition, sampled in late May, as well as in light-morph falcons. The observed ChEs activities, as well as nuclear and cellular/cytoplasmic abnormalities revealed that Eleonora's falcons are likely to be exposed to chemical agents with neurotoxic and cyto-genotoxic potential year round, while different aspects of their biology and ecology, such as their reproductive and nutritional status, could mediate their levels. Although we encourage more sampling campaigns to verify the identified seasonal and intrinsic sources of variation in biomarkers tested, the current study enriches the existing knowledge about their usefulness in the environmental monitoring and risk assessment of migratory birds, like Eleonoras' falcon.

How leachates from wasted cigarette butts influence aquatic life? A case study on freshwater mussel Anodontites trapesiali

There are several reports on the damage smoking causes to human health available in the literature, but little is known about the environmental and biological consequences from inappropriate cigarette butt (CB) disposal in urban and natural environments. The immunotoxic, morphotoxic and mutagenic potential of leachates from cigarette butts (LCB) diluted at environmentally relevant rates (LCB1x: 1.375%; LCB10x: 13.75%) was evaluated in adult representatives of the bivalve species Anodontites trapesialis, which was adopted as model organism. Type II hyalinocytes and granulocytes (phagocytic cells) frequency increased in the hemolymph of subjects exposed to the pollutant for 14 days. Based on this outcome, LCB chemical constituents did not induce immunotoxic effects. The treatments also did not seem to have any impact on the subjects' hemocitary morphometry parameters: diameter, area, perimeter, circularity and nucleus - cytoplasm ratio. However, subjects in groups LCB1x and LCB10x recorded a larger number of hyalinocytes with some nuclear abnormality such as micronucleus, blebbed nucleus, asymmetric constriction nucleus, and nuclear multilobulation and binucleation. The association between these abnormalities and the treatments was confirmed by the Cr, Ni, Pb, Zn, Mn and Na bioaccumulation in tissue samples of the bivalve models exposed to LCB. To the best of our knowledge, this is the first report on LCB mutagenicity in representatives of a freshwater bivalve group. Given the chemical complexity of the addressed pollutants, it is imperative to develop further investigations about the topic.

Pyrethrum extract encapsulated in nanoparticles: Toxicity studies based on genotoxic and hematological effects in bullfrog tadpoles

The environment receives about 2.7 kg.ha^-1 annually of pesticides, used in crop production. Pesticides may have a negative impact on environmental biodiversity and potentially induce physiological effects on non-target species. Advances in technology and nanocarrier systems for agrochemicals led to new alternatives to minimize these impacts, such as nanopesticides, considered more efficient, safe and sustainable. However, it is important to evaluate the risk potential, action and toxicity of nanopesticides in aquatic and terrestrial organisms. This study aims to evaluate genotoxic and hematological biomarkers in bullfrog tadpoles (Lithobates catesbeianus) submitted to acute exposure (48 h) to pyrethrum extract (PYR) and solid lipid nanoparticles loaded with PYR. Results showed increased number of leukocytes during acute exposure, specifically eosinophils in nanoparticle-exposed groups, and basophil in PYR-exposed group. Hematological analysis showed that PYR encapsulated in nanoparticles significantly increased the erythrocyte number compared to the other exposed groups. Data from the comet assay indicated an increase in frequency of the classes that correspond to more severe DNA damages in exposed groups, being that the PYR-exposed group showed a high frequency of class-4 DNA damage. Moreover, erythrocyte nuclear abnormalities were triggered by short-time exposure in all treatments, which showed effects significantly higher than the control group. These results showed genotoxic responses in tadpoles, which could trigger cell death pathways. Concluding, these analyses are important for applications in assessment of contaminated aquatic environments and their biomonitoring, which will evaluate the potential toxicity of xenobiotics, for example, the nanoparticles and pyrethrum extract in frog species. However, further studies are needed to better understand the effects of nanopesticides and botanical insecticides on non-target organisms, in order to contribute to regulatory aspects of future uses for these systems.

Assessment of DNA integrity through MN bioassay of erythrocytes and histopathological changes in Wallago attu and Cirrhinus mirigala in response to freshwater pollution

The aim of this study was to determine the level of contamination and genotoxic impact through micronucleus assay and histopathology in Wallago attu and Cirrhinus mrigala procured from the polluted site of the River Chenab at industrial and sewage waste disposal. The water sample was found viciously contaminated with heavy metals i.e. Ni, Cr, Mn, Co, Pb, Hg, Zn, Sn, Cu while all other physio-chemical variables crossed the suggested limits of WHO. The heavy metals load induced histopathological alterations were correlated to environmental degradation and the productivity of this biological system. W. attu and C. mrigala harvested from contaminated sites of the river indicated higher intensity of DNA damage through micronucleus induction and nuclear abnormalities with 5.46 ± 0.17, 1.23 ± 0.08 and 4.2 ± 0.11, 0.4 ± 0.04‰ respectively. Muscle sections of W. attu and C. mrigala harvested from the polluted section of river demonstrated the necrosis, degeneration of muscle fibers, intra-fibular edema and release of the blood into the tissues due to the bursting of blocked of the blood vessels. Dermal layers showed degeneration of the collagen bundles those were found loose or collapsed in some regions. Photomicrography also revealed vacuolar degeneration in muscle tissues and atrophy of muscle bundles. Intra fibular edema and splitting of muscle fibers were also seen along with bioaccumulation of toxicants. W. attu showed maximum incidence of alterations with highest histopathological alteration index related to environmental degradation. Control fish samples showed normal muscle tissues with normal equally spaced muscle bundles and myotomes.

Comparative study of phytotoxicity and genotoxicity of soil contaminated with biodiesel, diesel fuel and petroleum

The worldwide spillage of fossil fuels causes an ever-increasing environmental concern due to their resistance to biodegradation and toxicity. The diesel fuel is one of the derivative forms of petroleum that is widely used in the world. Its composition has many aromatic compounds and long hydrocarbons chains, both persistent and hazardous, thus requiring complex microbial dynamics to achieve full biodegradation. At this point, biodiesel has advantages because it is produced from renewable sources. It also has a relatively fast biodegradation. Biodiesel formulation chemically varies according to the raw material used for its production. While vegetable oils tend to have homogeneous proportions of linoleic and oleic fatty acids, animal fats have an heterogeneous distribution of stearic, palmitic and oleic fatty acids. As some studies have already detected the toxic potential of biodiesel from vegetable oil, this study sought information on the phytotoxic and genotoxic potential of animal fat-based biodiesel and compare it with fossil fuel as diesel fuel and crude petroleum. The impacts on the microbial activity of soils contaminated with biodiesel, diesel fuel and crude petroleum were performed by the dehydrogenase activity. Phytotoxicity tests were performed with Eruca sativa seeds and genotoxicity bioassays with Allium cepa seeds. The results showed a rapid assimilation of biodiesel by the autochthonous soil microorganisms. Soil contaminated with either diesel or crude petroleum inhibited the root and hypocotyl elongation of E. sativa. Overall, petroleum contaminated soils showed higher genotoxic potential. Biodiesel from animal fat was rapidly assimilated by soil microorganisms and did not present significant phytotoxic or genotoxic potential, but significantly reduced the mitotic index of A. cepa roots. Our results showed that biodiesel from animal fat have rapid biodegradability. Biodiesel also led to less impacts during seed development and lower genotoxic potential when compared to crude petroleum and diesel fuel. In addition, biodiesel from animal fat does not present the same toxicity demonstrated by biodiesel from soybean-based biodiesel described in current literature.

In Vivo Evaluation of the Genotoxic Effects of Poly (Butylene adipate-co-terephthalate)/Polypyrrole with Nanohydroxyapatite Scaffolds for Bone Regeneration

Here, butylene adipate-co-terephthalate/polypyrrole with nanohydroxyapatite (PBAT/PPy/nHAp) scaffolds were fabricated and characterized. The electrospinning process was carried out using 12 kV, a needle of 23 G, an infusion pump set at 0.3 mL/h, and 10 cm of distance. Afterwards, nHAp was directly electrodeposited onto PBAT/PPy scaffolds using a classical three-electrode apparatus. For in vivo assays (comet assay, acute and chronic micronucleus), 60 male albino Wistar rats with 4 groups were used in each test (n = 5): PBAT/PPy; PBAT/PPy/nHAp; positive control (cyclophosphamide); and the negative control (distilled water). Peripheral blood samples were collected from the animals to perform the comet test after 4 h (for damage) and 24 h (for repair). In the comet test, it was shown that the scaffolds did not induce damage to the % DNA tail and neither for tail length. After the end of 48 h (for acute micronucleus) and 72 h (for chronic micronucleus), bone marrow was collected from each rat to perform the micronucleus test. All of the produced scaffolds did not present genotoxic effects, providing strong evidence for the biological application of PBAT/PPy/nHAp scaffolds.

Genotoxic, cytotoxic, and neurotoxic responses in Anodonta cygnea after complex metal mixture treatment

Environmental effects associated with the release of various metals even at maximum permissible concentrations (MPC) to the aquatic ecosystems are evident. In the present work, time-dependent increase in accumulated metals amount in gills of Anodonta cygnea after exposure to complex metal (Zn 0.1, Cu 0.01, Ni 0.01, Cr 0.01, Pb 0.005, and Cd 0.005 mg/L, MPC accepted for the inland waters in EU) mixture at various time points (1, 2, 4, 7, 14, and 28 days) was investigated. Statistically significant increase of Cu and Cd was determined in mussel's gills after 7-day exposure, in comparison to control group; moreover, significantly elevated concentration of Cu was measured and after 14-day treatment (in comparison to control and pre-exposure group). Concentrations of five (Cu, Ni, Cr, Pb, and Cd) out of 6 investigated metals were statistically increased in gills tissue after 28-day treatment. Moreover, complex metal mixture has demonstrated tissue- and time-dependent genotoxicity (∑Gentox) and cytotoxicity (∑Cytox) responses in mussels. After 4-day exposure, there were found the highest ∑Gentox levels in gills cells and haemocytes. Two-day treatment of mussels resulted in the highest and statistically significant induction of ∑Cytox level (in gills). Furthermore, after short-term (4 days) exposure, statistically significant inhibition of AChE activity in hemolymph of metal mixture-exposed mussels, in comparison to control and pre-exposure group, was found. Comparison of investigated responses in different tissue of A. cygnea discloses new information about metal mixture (at MPC) impacts at different treatment time. According to the obtained geno- and cytotoxicity data, it is suggested that gills are more sensitive tissue. Environmentally relevant trace metal concentrations when existing in mixture are able to cause adverse effects in A. cygnea; therefore, biological effects at different levels of organism are expected as a realistic scenario.

Evaluation in situ of genotoxic and cytotoxic response in the diploid/polyploid complex Odontophrynus (Anura: Odontophrynidae) inhabiting agroecosystems

Polyploidization has been documented across a wide range of vertebrates. Gene duplication could promote better adaptation to environmental changes and to chronic injury or stress. We investigated if genotoxic and cytotoxic responses to agricultural impact are affected by ploidy. We evaluate syntopic populations of the cryptic diploid/polyploid complex Odontophrynus cordobae/O. americanus breeding in an agroecosystem from Central Argentina. The blood of 72 adult anurans was analysed. We used erythrometry to distinguish Odontophrynus individuals with different ploidy levels. We calculated micronucleus frequencies (Mn) and erythrocytic nuclear abnormalities (ENAs) as genotoxic effects and enucleated, mitotic, pyknotic and immature erythrocytes as cytotoxic endpoints (CYT). Mn, ENAs and CYT frequencies were significantly different between diploid and polyploid organisms. The higher frequencies of Mn and CYT were recorded in polyploid organisms, and the higher frequency of ENAs was recorded in diploids. These results indicate that stress response, as indicated by most genotoxic and cytotoxic endpoints, was higher in polyploids respect to diploids. Polyploidy could provide greater genetic flexibility increasing buffering against exogenous DNA-damaging agents and thus confer an advantage over diploids under certain environmental conditions.

Doramectin induced cytotoxic and genotoxic effects on bovine peripheral lymphocytes and cumulus cells in vitro

The effect of doramectin (DOR) was tested on two experimental somatic bovine cells in vitro: peripheral lymphocytes (PL) and cumulus cells (CC). The cytotoxicity and genotoxicity of DOR were assessed using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay, single cell gel electrophoresis assay (SCGE) and cytokinesis-block micronucleus cytome (CBMN Cyt) assay. Both cells were treated with three concentrations of DOR (20, 40, 60 ng mL^-1) for 24 h. The results obtained from PL demonstrated that DOR was able to induce cytotoxic effect and DNA damage with all concentrations tested. Additionally, DOR increased micronuclei (MNi) frequency and nuclear buds (NBuds) with 20, 40, 60 ng mL^-1, and nucleoplasmic bridges (NPBs) only with 40 ng mL^-1. On the other hand, the three concentrations of DOR were not able to induce cytotoxic effect and DNA damage using SCGE in the bovine CC. Nevertheless, the two higher concentrations of DOR (20, 40 µg mL^-1) significantly increased the frequency of micronucleus formation in bovine CC. These results represent the first experimental evidence of genotoxic and cytotoxic effects exerted by DOR on bovine PL and CC.

Environmental genotoxicity and risk assessment in the Gulf of Riga (Baltic Sea) using fish, bivalves, and crustaceans

Environmental genotoxicity in the Gulf of Riga was assessed using different bioindicators (fish, clams, and isopods) collected from 14 study stations. Comparison of genotoxicity responses (micronuclei (MN) and nuclear buds (NB)) in blood erythrocytes of herring (Clupea harengus), eelpout (Zoarces viviparous), and flounder (Platichthys flesus) revealed the species- and site-specific differences. For the first time, the analysis of genotoxicity was carried out in gill cells of isopods Saduria entomon. The highest inductions of MN and NB in gill cells of investigated S. entomon and clams (Macoma balthica) were evaluated in specimens from station 111A (offshore zone). In fish, the highest incidences of MN were measured in eelpout and in herring collected in the southern part of Gulf of Riga (station GOR3/41S). Moreover, in the southern coastal area, the assessment of genotoxicity risk (according to micronuclei levels) indicated exceptionally high risk for flounder, eelpout, and clams.

Fish eco-genotoxicology: Comet and micronucleus assay in fish erythrocytes as in situ biomarker of freshwater pollution

Owing to white meat production Labeo rohita have vast economic importance, but its population has been reduced drastically in River Chenab due to pollution. Atomic absorption spectrophotometry showed a merciless toxicity level of Cd, Cu, Mn, Zn, Pb, Cr, Sn and Hg. Comet assay results indicated significant (p < .05) DNA fragmentation in Labeo rohita as 42.21 ± 2.06%, 31.26 ± 2.41% and 21.84 ± 2.21% DNA in comet tail, tail moment as 17.71 ± 1.79, 10.30 ± 1.78 and 7.81 ± 1.56, olive moment as 13.58 ± 1.306, 8.10 ± 1.04 and 5.88 ± 0.06, respectively, from three different polluted sites on the river. Micronucleus assay showed similar findings of single micronucleus induction (MN) as 50.00 ± 6.30‰, double MN 14.40 ± 2.56‰, while nuclear abnormalities (NA) were found as 150.00 ± 2.92‰. These higher frequencies of MN induction and NA were found to be the cause of reduction of 96% of the population of this fish species in an experimental area of the River Chenab. This fish species has been found near extinction through the length of the river Chenab and few specimens in rainy seasons if restored by flood, may die in sugarcane mill season. Due to sweeping extinction Labeo rohita showed the highest sensitivity for pollution and could be used as bioindicator and DNA fragmentation in this column feeder fish species as a biomarker of the pollution load in freshwater bodies.

Effects of humic acids from landfill leachate on plants: An integrated approach using chemical, biochemical and cytogenetic analysis

Biological process treatment of landfill leachate produces a significant amount of sludge, characterized by high levels of organic matter from which humic acids are known to activate several enzymes of energy metabolism, stimulating plant growth. This study aimed to characterize humic acids extracted from landfill sludge and assess the effects on plants exposed to different concentrations (0.5, 1, 2 and 4 mM C L^-1) by chemical and biological analysis, to elucidate the influence of such organic material and minimize potential risks of using sludge in natura. Landfill humic acids showed high carbon and nitrogen levels, which may represent an important source of nutrients for plants. Biochemical analysis demonstrated an increase of enzyme activity, especially H⁺-ATPase in 2 mM C L^-1 landfill humic acid. Additionally, cytogenetic alterations were observed in meristematic and F₁ cells, through nuclear abnormalities and micronuclei. Multivariate statistical analysis provided integration of physical, chemical and biological data. Despite all the nutritional benefits of humic acids and their activation of plant antioxidant systems, the observed biological effects showed concerning levels of mutagenicity.

Genotoxic effects and gene expression in Danio rerio (Hamilton 1822) (Cypriniformes: Cyprinidae) exposed to mining-impacted tributaries in Manizales, Colombia

The zebrafish (Danio rerio) is one of the most studied aquatic organisms for water biomonitoring, due to its sensitivity to environmental degradation and resistance to toxic substances. This study determined the presence of micronuclei and nuclear abnormalities in peripheral blood erythrocytes, and assessed the gene expression of caspase-3 (CASP-3) and metallothionein 1 (MT-1) in the gills and liver of D. rerio. The study fish (n = 45) were exposed to water collected from two stations with mining impact (E2 and E3) and a reference station without evident mining contamination (E1), all located in La Elvira stream (Manizales-Colombia). In addition, a positive control (PC) with HgCl₂ (50 μg/L) and negative control (NC) with tap water were included. The fish from the PC and E2 and E3 treatments displayed genotoxic effects and changes in gene expression, with significant differences in micronuclei formation and the presence of blebbed nuclei. The cytochrome oxidase subunit I (COI) gene was used as reference and proved to be stable compared to the β-actin and 28S ribosomal RNA (28S) genes. In gills, CASP-3 expression was higher in the PC, and MT-1 expression was higher in the PC and E3 treatment. In liver, CASP-3 was expressed in the E2 treatment, and MT-1 expression was low. These results show that the genotoxic effects and differential gene expression observed in fish exposed to water from La Elvira stream could also be affecting the organisms present in this habitat.

The genotoxicity and cytotoxicity of tannery effluent in bullfrog (Lithobates catesbeianus)

Some of the most polluting activities occur in bovine skin processing. Tannery generates effluents containing high concentrations of heavy metals and organic compounds. The phases composing the leather production process generate a large volume of tannery effluents that are often discarded in aquatic environments without any previous treatment. However, the effect these xenobiotics have on adult representatives belonging to the class Amphibia remains unknown. Thus, the aim of the present study is to assess the geno- and cytotoxic effects of tannery effluent on adult male bullfrogs (Lithobates castesbeianus) exposed to it. Accordingly, the animals were divided into the following groups: negative control (tannery effluent-free water), positive control (cyclophosphamide), and effluent (water added with 5% tannery effluent). The animals were euthanized for blood collection, and erythrocyte analyses were conducted after 35 and 90 days of exposure. The micronuclei (MN) frequency and the frequency of other nuclear abnormalities in each of the animals in the experimental groups were assessed in 2000 erythrocytes. According to the present results, the exposure to tannery effluents increased MN frequency as well as other nuclear abnormalities (i.e., lobed nuclei, binucleated cell, kidney-shaped nuclei, notched nuclei, and apoptotic cell) in the erythrocytes of animals in the effluent group and in the positive control group after 35 and 90 exposure days. Thus, the current study corroborated the hypothesis that the tannery effluent has aneugenic and clastogenic potential in adult male bullfrogs (L. castesbeianus). The present study is the first to report such effect.

NIVELES SANGUÍNEOS DE BIOMARCADORES DE DAÑO GENÉTICO EN ERITROCITOS DE Lepidochelys olivacea (Cheloniidae) EN COLOMBIA

Esta investigación se realizó en el municipio de Bahía Solano, Colombia y tuvo como objetivos: 1) detectar la circulación de eritrocitos con lesiones nucleares en 55 hembras adultas de tortuga golfina (Lepidochelys olivacea), empleando la inmunotinción de naranja de acridina y 2) correlacionar sus frecuencias con aspectos biométricos y fisiológicos. Se determinó una frecuencia de eritrocitos con micronúcleos (EMN) de 0,6 ± 0,6 y de protuberancias nucleares (EPN) de 2,1 ± 1,9.  Mediante un análisis multivariado a través de la correlación de Pearson y de Kruskal-Wallis (p<0,05), no se encontró ninguna correlación positiva entre el nivel de frecuencia de EPN ni de EMN con los parámetros biométricos y fisiológicos evaluados. Se estableció una diferencia estadísticamente significativa (p= 0,035) entre las frecuencias de EPN y de EMN. Los resultados hallados indican que esta especie presenta eritrocitos circulantes con los daños nucleares mencionados y reporta por primera vez la presencia de estrés genotóxico para la especie en Colombia. Así mismo, brinda información clave para investigaciones posteriores en el área de la ecotoxicología de especies marinas amenazadas.

GENOTOXICIDADE E CITOTOXICIDADE DOS RAIOS X EM CRIANÇAS SUBMETIDAS À RADIOGRAFIA PANORÂMICA

RESUMO Objetivo: Analisar a genotoxicidade e a citotoxicidade produzidas por raios X no epitélio da mucosa oral de crianças durante a obtenção da radiografia panorâmica. Métodos: A amostra foi constituída por 30 crianças saudáveis, sendo 19 do sexo feminino e 11 do masculino, com faixa etária de 4 a 10 anos (média de 7 anos de idade). As células epiteliais da mucosa oral foram coletadas por meio de citologia esfoliativa em base líquida imediatamente antes e após sete dias da obtenção da radiografia panorâmica. Os esfregaços foram processados e corados utilizando a técnica de Feulgen Rossenbeck modificada. Foram analisadas e quantificadas projeções nucleares dos tipos bud e broken egg, alterações genotóxicas na forma de micronúcleo e alterações citotóxicas dos tipos picnose, cariólise e cariorrexe. Resultados: A frequência de picnose, bud e broken egg foi significativamente maior após a exposição aos raios X (p<0,05), porém não houve diferença estatisticamente significante em relação ao sexo, bem como nas demais alterações estudadas. Conclusões: A exposição aos raios X emitidos durante a obtenção da radiografia panorâmica pode induzir à morte celular no epitélio da mucosa oral de crianças. Não foi encontrado indício significativo de efeito genotóxico.

Toxic effects of environmental pollutants: Comparative investigation using Allium cepa L. and Lactuca sativa L

Studies that help understand the mechanisms of action of environmental pollutants are extremely important in environmental toxicology. In this context, assays using plants as models stand out for their simplicity and low performance cost. Among the plants used for this purpose, Allium cepa L. is the model most commonly applied for cytogenotoxic tests, while Lactuca sativa L., already widely used in phytotoxic investigations, has been gaining prominence in cytotoxic analyses. The present study aimed to compare the responses of A. cepa and L. sativa via macroscopic (root growth) and microscopic analyses (cell cycle and DNA fragmentation via TdT-mediated deoxy-uracil nick and labeling (TUNEL) and comet assays) after exposure of their roots to environmental pollutants with known cytogenotoxic mechanisms. Both species presented sensitive and efficient response to the applied tests after exposure to the DNA-alkylating agent Methyl Methanesulfonate (MMS), the heavy metal Cadmium, the aluminum industry waste Spent Potliner (SPL) and the herbicide Atrazine. However, they differed regarding the responses to the evaluated endpoints. Overall, A. cepa was more efficient in detecting clastogenic changes, arising from DNA breakage, while L. sativa rather detected aneugenic alterations, related to chromosome segregation in mitosis. In the tests applied to verify DNA fragmentation (comet and TUNEL assays), A. cepa presented higher sensitivity. In conclusion, both models are efficient to evaluate toxicological risks of environmental pollutants.

In vitro and in vivo investigation of the genotoxic potential of waters from rivers under the influence of a petroleum refinery (São Paulo State - Brazil)

In recent years concern about the chemical composition of wastewater generated by the oil refining industry has increased, even after its treatment. These wastewaters contain substances that can harm both the entire aquatic ecosystem and the health of any exposed organisms. The aim of this study was to evaluate the genotoxic and mutagenic potentials of the effluent generated by the largest Brazilian petroleum refinery, the effectiveness of the treatments used by the refinery, and whether its effluent can compromise the water quality of the river where it is discarded. Chromosomal aberration and micronucleus assays were performed in Allium cepa and micronucleus test in mammalian cell culture (CHO-K1). The samples were collected in three sites at the refinery: one site on the Jaguari River and two sites on the Atibaia Rivers (upstream and downstream of the discharged effluent), under three different climatic conditions. Tests with A. cepa showed increased frequencies of chromosomal aberrations and micronuclei in meristematic cells for the effluent after physico-chemical treatment, but the samples after treatment biological and stabilization pond presented none of these abnormalities. It was observed that the induced damage in the meristematic cells was not observed in the F₁ cells of A. cepa roots. The micronucleus test performed with mammalian cell culture also indicated that the effluent, after physico-chemical treatment, induced a significant increase in micronucleus frequencies. Plant and hamster cells exposed to the other samples collected inside the refinery and in the Jaguari and Atibaia Rivers did not present evidence of genotoxicity and mutagenicity in the tests performed. This study showed that the effluent treated carried out by the refinery (biological treatment followed by a stabilization pond) proved to be efficient for the removal of the toxic load still present after the physico-chemical treatment, since no change in the quality of the Atibaia River was observed. However, because this is an industry with a high production of effluent with toxic potential, its effluents must be constantly monitored, so that there is no compromise of the water quality of the receiving river.

Aneugenicity and clastogenicity in freshwater fish Oreochromis niloticus exposed to incipient safe concentration of tannery effluent

Conventional effluent bioassays mostly rely on overt responses or endpoints such as apical and Darwinian fitness. Beyond the empirical observation, laboratory toxicity testing needs to rely on effective detection of prognostic biomarkers such as genotoxicity. Indeed, characterization of tannery effluent requires slotting in of genotoxic responses in whole effluent toxicity testing procedures. Hence, the prime objective of the present experimental investigation is to apply the technique of biological assay as a tool of toxicity testing to evaluate the induction of micronuclei (MN) in peripheral erythrocytes, and exfoliated cells of gill and kidney of O.niloticus exposed to Maximum tolerable concentrations (MTCs) of composite Modjo tannery effluent (CMTE) and to compare the sensitivity of each cells origin to the induction of MN. After 72h of exposure, cellular aberrations were detected using MN and nuclear abnormality (NA) tests. The induction of MN was significantly higher in exposed groups (P<0.05) when compared to the control group; moreover the tissue specific MN response was in the order, gill cells>peripheral erythrocyte>kidney. Total NA was found to increase significantly (P<0.05), when compared to the non-exposed group. NA was also further ramified as blebbed (BL), bi-nucleated (BN), lobbed (LB) and notched (NT) abnormalities. The result of each endpoint measured has demonstrated that at a concentration of total chromium (0.1, 0.73 and 1.27mg/L), a perceptible amount cellular aberration was measured, further implicating somber treat of genotoxicity to fishes, if exposed to water contaminated with tannery effluent. This further highlight that conventional effluent monitoring alone cannot reveal the effects expressed at cellular and genetic levels further demanding the incorporation of effluent bioassays in risk assessment and risk management/abatement programs.

Microelectrophoretic study of environmentally induced DNA damage in fish and its use for early toxicity screening of freshwater bodies

This study investigates the potential of the comet and micronucleus assays of fish DNA as a means of screening the toxicity of aquatic environments. Catla catla and Cirrhinus mrigala collected from the River Chenab in Pakistan were used as a case study for the application of comet and micronucleus techniques. Comet and micronucleus assays were used to compare DNA damage in C. catla and C. mrigala collected from polluted areas of the River Chenab and farmed fish. Atomic absorption spectrophotometry showed an acute level of toxicity from Cd, Cu, Mn, Zn, Pb, Cr, Sn, and Hg in river water. Comet assay showed significant (p < 0.05) DNA damage in C. catla representing 17.33 ± 2.42, 11.53 ± 2.14, and 14.17% DNA in the comet tail, averaged from three sites of the polluted area of the river. Tail moment was observed as 10.06 ± 2.71, 3.11 ± 0.74, and 14.70 ± 1.89, while olive moment was 8.85 ± 1.84, 3.83 ± 0.76, and 7.11 ± 0.73, respectively. Highly significant (p < 0.01) damage was reported in C. mrigala as 37.29 ± 2.51, 34.96 ± 2.53, and 38.80 ± 2.42% DNA in comet tail, tail moment was 23.48 ± 3.90, 19.78 ± 4.26, and 14.30 ± 1.82, and olive moment was 16.22 ± 2.04, 13.83 ± 1.96, and10.99 ± 0.90. Significant (p < 0.05) differences were observed in genotoxicity between farmed and polluted area fish. Micronucleus assay showed a similar picture of significant difference in respect to single and double micronucleus induction: i.e., 23.20 ± 4.19 and 2.80 ± 1.07‰ in C. catla and 44.80 ± 3.73 and 06.20 ± 0.97‰, respectively, in C. mrigala. Nuclear abnormalities were found as 6.00 ± 0.84 and 09.60 ± 1.72/thousand cells, respectively, in both species. The results of this study suggest that these novel fish DNA damage assays can be used as an expedient toxicity screening for aquatic environments.

Assessment in situ of genotoxicity in tadpoles and adults of frog Hypsiboas cordobae (Barrio 1965) inhabiting aquatic ecosystems associated to fluorite mine

Non-lethal biological techniques such as blood biomarkers have gained attention due to their value as early signals of anthropic effects of contamination representing significant tools to evaluate ecosystems health. We evaluate and characterize in situ genotoxicity of water samples collected from aquatic ecosystems around a fluorite mine using amphibian frogs Hypsiboas cordobae as bioindicator species complemented with 16 physicochemical parameters. Four stations associated with fluorite mine sampling were sampled: a stream running on granitic rock with natural high fluorite content; two streams both running on metamorphic rock with low fluorite content; and an artificial decantation pond containing sediments produced by fluorite flotation process with high variation in physicochemical parameters. We analyses the blood of tadpoles and adults of H. Cordobae, calculated frequencies of micronuclei, erythrocyte nuclear abnormalities, mitosis, immature and enucleated erythrocytes. Individuals were measured and weighed and body condition was calculated. The results of this study indicate that individuals of decantation pond are exposed to compounds or mixtures which are causing cell damage when compared to those that were collected of stream. Larval stage was more vulnerable than the adult phase and it could be related mainly to the higher exposure time to xenobiotics, which can penetrate easily by skin, mouth and gills; additionally this site offers a reduced availability of food than other sites. Therefore, chronic exposure to pollutants could derive in degenerative and neoplastic diseases in target organs. Moreover these individuals may experience reproductive and behavioral disturbances which could lead to population decline in the long term.

Variation in genotoxic susceptibility and biomarker responses in Cirrhinus mrigala and Catla catla from different ecological niches of the Chenab River

A large number of methods have been applied to evaluate genotoxic damage in different aquatic species. Comet assay, as a method for detecting DNA alterations, and micronucleus test, as an index of chromosomal damage are the most widely used and authentic methods in laboratory and field studies. The primary objective of the study was to evaluate the genotoxic effects of heavy metals generated by toxic industrial effluents and various kinds of pollutants from urban and agricultural areas and domestic waste on Catla catla and Cirrhinus mrigala due to water pollution in the Chenab River, Pakistan. The heavy metals Cd, Cu, Mn. Zn, Pb, Cr, Sn, and Hg were detected by atomic absorption spectrophotometry from water samples collected from predetermined sampling sites. All the physicochemical parameters and heavy metals were found to exceed the upper limits recommended by various agencies. Comet assays showed significant (p < 0.05) DNA damage in C. mrigala compared to C. catla for tail length and olive tail moment from three different sites. Significant (p < 0.05) differences were reported between fish collected from polluted sites and farmed fish, but only non-significant (p > 0.05) findings were observed between fish collected from farmed and non-polluted upstream waters. Micronucleus assays showed similar findings for single and double micronucleus induction in C. catla and C. mrigala. A significantly (p < 0.05) higher micronuclei induction and percent tail DNA was observed in C. mrigala specimen collected from the polluted site. These findings infer that DNA damage could be used as a biomarker of pollution load and its early monitoring by using simple and reliable techniques such as the comet and micronucleus assays, expedient methods for toxicity screening of aquatic environments. Regular monitoring is necessary to assess eco-health of the Chenab River by choosing perhaps C. mrigala, being a bottom feeder, as a bioindicator that could provide more reliable information to determine the status of the environmental quality of the river.

Effect of acute exposure to nonylphenol on biochemical, hormonal, and hematological parameters and muscle tissues residues of Nile tilapia; Oreochromis niloticus

Aim:

This study was aimed to evaluate some biochemical, hormonal, hematological, and histopathological changes in Nile tilapia, Oreochromis niloticus, after acute exposure to nonylphenol (NP). In addition to detection of NP residues in the fish, muscle tissues for human health concern.

Materials and Methods:

A total of 90 apparently healthy Nile tilapia, O. niloticus, were randomly divided into three equal groups; each containing 30 fish (three replicates). Groups 1 and 2 kept as a control and solvent control (acetone), respectively, and Group 3 exposed to NP at a dose level of 500 µg/L water for 7 successive days. Blood and tissue samples were collected 2 times randomly from each group after 7 days from fish exposure to NP and 10 days from exposure stopping.

Results:

Fish exposed to NP Group 3 showed anorexia, sluggish movement, erythema of the skin, areas of scales loss, and hemorrhagic ulcers in some areas of body region leading to exposing the viscera. Biochemical results revealed a significant increase in serum total proteins and globulins levels, a highly significant increase in serum alanine aminotransferase and aspartate aminotransferase activities, triglycerides, cholesterol, and creatinine levels, insignificant increase in serum uric acid level, and a highly significant decrease in serum testosterone and estradiol-β17 levels in Group 3 in compare with the control group. Histopathological finding confirms these results. While hematological results of the same group revealed a significant increase in red blood cells count and packed cell volume value, insignificant increase in hemoglobin concentration, leukopenia, lymphopenia, and monocytopenia in compared with the control group. All of these changes appeared after 7 days from fish exposure to NP. Most of these alterations returned toward the normal level after 10 days from stopping exposure to NP. NP residues detected in fish muscle tissues of Group 3 during exposure and after stopping exposure to it.

Conclusion:

It is concluded that NP is a toxic pollutant and has an adverse effect on fish health and reproduction as well as accumulates in fish muscle tissues which may cause human health hazard.

Monitoring Genotoxicity Potential in the Mumbuca Stream, Minas Gerais, Brazil

Rivers are sites for water catchment to supply metropolitan areas but also serve as receptors for discharge of urban sewage, wastewater, and agri-industrial effluents. Bioindicators or sentinel organisms are widely used as markers of pollution in various environments. The objective of this study was to evaluate the genotoxic potential and consequent quality of the water from the Mumbuca stream, which supplies the city of Monte Carmelo, located in the Minas Triangle region, Minas Gerais, Brazil. This was achieved using two variable response bioindicators (Rhamdia quelen and Geophagus brasiliensis), the micronucleus (MN) test, and determining the presence of metals by flame atomic absorption spectrometry. Results showed that site 3 water (region of residential flow and intense industrial pottery activity) presented a greater possibility for induction of genotoxic activity, as evidenced by the increase in the MN frequency in Rhamdia quelen and Geophagus brasiliensis in comparison with the reference-site water. The water of the Mumbuca stream was influenced by genotoxic agents, especially lead and chromium, assessed by the rise in MN rate. Data suggested that discharge of industrial effluents in a specific stretch of the stream interfered with biota functions.

Analysis of the genotoxic potential of low concentrations of Malathion on the Allium cepa cells and rat hepatoma tissue culture

Based on the concentration of Malathion used in the field, we evaluated the genotoxic potential of low concentrations of this insecticide on meristematic and F1 cells of Allium cepa and on rat hepatoma tissue culture (HTC cells). In the A. cepa, chromosomal aberrations (CAs), micronuclei (MN), and mitotic index (MI) were evaluated by exposing the cells at 1.5, 0.75, 0.37, and 0.18mg/mL of Malathion for 24 and 48hr of exposure and 48hr of recovery time. The results showed that all concentrations were genotoxic to A. cepa cells. However, the analysis of the MI has showed non-relevant effects. Chromosomal bridges were the CA more frequently induced, indicating the clastogenic action of Malathion. After the recovery period, the higher concentrations continued to induce genotoxic effects, unlike the observed for the lowest concentrations tested. In HTC cells, the genotoxicity of Malathion was evaluated by the MN test and the comet assay by exposing the cells at 0.09, 0.009, and 0.0009mg/5mL culture medium, for 24hr of exposure. In the comet assay, all the concentrations induced genotoxicity in the HTC cells. In the MN test, no significant induction of MN was observed. The genotoxicity induced by the low concentrations of Malathion presented in this work highlights the importance of studying the effects of low concentrations of this pesticide and demonstrates the efficiency of these two test systems for the detection of genetic damage promoted by Malathion.

In vivo genotoxicity and cytotoxicity assessment of cadmium chloride in peripheral erythrocytes of Labeo rohita (Hamilton)

Cadmium chloride (CdCl2) induced genotoxicity and cytotoxicity has been assessed in the peripheral blood erythrocytes of freshwater fish Labeo rohita exposed to 0.37 and 0.62mg/L of CdCl2 in water for 100 days. The blood samples of the fish were collected at different intervals (days 1, 3, 5, 10, 15, 30, 60 and 100) of exposure period to analyze DNA damage using comet assay and the occurrence of micronuclei and other cellular anomalies. The results of comet assay showed a significant increase in the mean percentage of tail DNA at both the concentrations. Exposure to CdCl2 also induced micronuclei in addition to many nuclear abnormalities such as nuclear bud, binucleates, lobed, notched and vacuolated nuclei. Cytoplasmic abnormalities like echinocytes, acanthocytes, notched, microcytes and cells with vacuolated cytoplasm were also observed. The metal exposed groups showed significant variation in the frequency of cellular abnormalities as well as the extent of DNA damage in comparison to controls. These frequencies increased significantly (p<0.05) in concentration dependent manner, peaking on 10th day while a decreasing trend was observed after 15 days of the exposure period.

Seahorse (Hippocampus reidi) as a bioindicator of crude oil exposure

This study explored the suitability of the seahorse Hippocampus reidi (Ginsburg, 1933) for assessing biomarkers of genotoxic effects and its use as a sentinel organism to detect the effects of acute exposure to petroleum hydrocarbons. Fish were exposed to three concentrations of crude oil (10, 20 and 30 g/kg) for 96 h, and the activity of phase II biotransformation enzyme glutathione S-transferase (GST) was measured. In addition, we performed genotoxicity assays, such as comet assay, micronucleus (MN) test and nuclear abnormalities (NA) induction, on the erythrocytes of the fish species. Our results revealed that the inhibition of hepatic GST activity in H. reidi was dependent on increasing crude oil concentrations. In contrast, an increase in the damage index (DI) and MN frequency were observed with increased crude oil concentrations. These results indicate that the alkaline comet assay and micronucleus test were suitable and useful in the evaluation of the genotoxicity of crude oil, which could improve determinations of the impact of oil spills on fish populations. In addition, H. reidi is a promising "sentinel organism" to detect the genotoxic impact of petroleum hydrocarbons.

Genotoxic effects of the antimalarial drug lumefantrine in human lymphocytes in vitro and computational prediction of the mechanism associated with its interaction with DNA

Lumefantrine (LF) is an aryl-amino alcohol antimalarial drug used in artemisinin-based combination therapies against malaria worldwide. In this study, we investigated the genotoxic effects of LF in human lymphocytes in vitro, and the potential noncovalent interaction of LF with DNA using a 3D DNA-docking model. The number of DNA breaks and the frequency of nuclear buds (NBUDS) was significantly increased (P < 0.01 and P < 0. 05, respectively) at LF concentrations of 60, 80, and 100 µg/mL (LF60, LF80, and LF100, respectively). Frequency (‰) of micronuclei (MN) formation also increased after LF treatments. However, this was only significant for LF100 (P = 0.01) and LF80 (P = 0.001). LF did not affect the frequency of nucleoplasmic bridges (NPBs) (P = 0.12) or the nuclear division index (NDI) (P = 0.32). Computational analysis suggests that LF may interact noncovalently with DNA via the DNA minor groove surface with a predicted binding affinity energy of -7.2 kcal/mol and showing a favorable shape complementary to this groove. Our results suggest that LF has clastogenic effects in human lymphocytes in vitro due to noncovalent interaction with the minor groove of DNA.

Effects on g2/m phase cell cycle distribution and aneuploidy formation of exposure to a 60 Hz electromagnetic field in combination with ionizing radiation or hydrogen peroxide in l132 nontumorigenic human lung epithelial cells

The aim of the present study was to assess whether exposure to the combination of an extremely low frequency magnetic field (ELF-MF; 60 Hz, 1 mT or 2 mT) with a stress factor, such as ionizing radiation (IR) or H2O2, results in genomic instability in non-tumorigenic human lung epithelial L132 cells. To this end, the percentages of G2/M-arrested cells and aneuploid cells were examined. Exposure to 0.5 Gy IR or 0.05 mM H2O2 for 9 h resulted in the highest levels of aneuploidy; however, no cells were observed in the subG1 phase, which indicated the absence of apoptotic cell death. Exposure to an ELF-MF alone (1 mT or 2 mT) did not affect the percentages of G2/M-arrested cells, aneuploid cells, or the populations of cells in the subG1 phase. Moreover, when cells were exposed to a 1 mT or 2 mT ELF-MF in combination with IR (0.5 Gy) or H2O2 (0.05 mM), the ELF-MF did not further increase the percentages of G2/M-arrested cells or aneuploid cells. These results suggest that ELF-MFs alone do not induce either G2/M arrest or aneuploidy, even when administered in combination with different stressors.

Hematological and biochemical investigations on the effect of vitamin E and C on Oreochromis niloticus exposed to zinc oxide nanoparticles

This study was carried out to determine the LC₅₀ of zinc oxide nanoparticles (ZnONPs) on Oreochromis niloticus and to investigate the effect of vitamin E and C on hematological and biochemical alterations induced by two sublethal concentrations (1 and 2 mg/L) of ZnONPs. One hundred and eighty fish were used for studying the lethal concentrations of ZnONPs. For sublethal study two hundred and twenty-five males of O. niloticus were equally divided into five groups, control, the second and the third were treated with 1 and 2 mg/L ZnONPs respectively. The fourth and fifth were exposed to the same concentrations of ZnONPs plus vitamins E and C. The results revealed that the 96 h LC₅₀ of ZnONPs was 3.1 ± 0.4 mg/L. The sublethal study revealed the presence of normocytic normochromic anemia in groups (2, 3 and 5) along the experiment period. The 4th group showed normocytic normochromic anemia at the 7th day and microcytic hypochromic anemia at the 15th day. Leukocytosis, heterophilia, lymphopenia and monocytopenia were recorded at the 7th day in all treated groups compared with the normal control. At the 15th day heteropenia, lymphopenia and monocytopenia were reported in all treated groups. A significant increase in the serum levels of alkaline phosphatase, aminotransferases, urea, creatinine and erythrocytic nuclear and morphological abnormalities along the experimental periods in all treated groups compared with the normal control. Serum total protein and albumin levels were significantly decreased at the same period in the same groups. Addition of vitamin E and C to the diet (groups 4 and 5) significantly improved all measured parameters compared with groups (2 and 3) which treated with ZnONPs only.

Selective protection of zidovudine-induced DNA-damage by the antioxidants WR-1065 and tempol

The cytokinesis-block micronucleus cytome (CBMN) assay, introduced by Fenech, was used to demonstrate different types of DNA damage in MOLT-3 human lymphoblastoid cells exposed to 10 μM zidovudine (AZT). In addition, we explored the cytoprotective potential of two antioxidants, WR-1065 and Tempol, to decrease AZT-induced genotoxicity. Binucleated cells, arrested by Cytochalasin B (Cyt B), were evaluated for micronuclei (MN), caused by DNA damage or chromosomal loss, and chromatin nucleoplasmic bridges (NPBs), caused by telomere attrition. Additionally, nuclear buds (NBUDs), caused by amplified DNA, and apoptotic and necrotic (A/N) cells were scored. We hypothesized that AZT exposure would increase the frequency of genotoxic end points, and that the antioxidants Tempol and WR-1065 would protect against AZT-induced genotoxicity. MOLT-3 cells were exposed to 0 or 10 µM AZT for a total of 76 hr. After the first 24 hr, 0 or 5 µM WR-1065 and/or 0 or 200 µM Tempol were added for the remainder of the experiment. For the last 28 hr (of 76 hr), Cyt B was added to arrest replication after one cell division, leaving a predominance of binucleated cells. The nuclear division index (NDI) was similar for all treatment groups, indicating that the exposures did not alter cell viability. MOLT-3 cells exposed to AZT alone had significant (P < 0.05) increases in MN and NBs, compared to unexposed cells. Both Tempol and WR-1065 protected against AZT-induced MN formation (P < 0.003 for both), and WR-1065, but not Tempol, reduced the levels of A/N (P = 0.041). In cells exposed to AZT/Tempol there were significantly reduced levels of NBUDs, compared to cells exposed to AZT alone (P = 0.015). Cells exposed to AZT/WR-1065 showed reduced levels of NPBs, compared to cells exposed to AZT alone (P = 0.037). Thus WR-1065 and Tempol protected MOLT-3 cells against specific types of AZT-induced DNA damage.

The role of vitamins A, C, E and selenium as antioxidants against genotoxicity and cytotoxicity of cadmium, copper, lead and zinc on erythrocytes of Nile tilapia, Oreochromis niloticus

This study was carried out to investigate the genotoxic and cytotoxic potentials of sublethal concentration (5mg L(-1)) of combined metals including Cd, Cu, Pb and Zn (1.25mg L(-1) of each) on erythrocytes of Nile tilapia, Oreochromis niloticus after exposure for five and seven days; and to evaluate the protective role of vitamin E alone and a combination of selenium (Se) with vitamins A, C and E which was added to the diet as antioxidants against the genotoxicity and cytotoxicity of these metals. This was accomplished by application of micronuclei (MN), binuclei (BN), nuclear abnormalities (NAs) assays in addition to morphological erythrocyte alteration (MAEs) assay. The results revealed that, exposure of O. niloticus to Cd, Cu, Pb and Zn induced the formation of nine genotoxic endpoints including MN, BN and seven patterns of NAs, kidney-shaped nuclei, blebbed nuclei, lobed nuclei, bilobed nuclei, notched nuclei, hook-shaped nuclei and vacuolated nuclei; and five patterns of morphological malformations were recorded as cytotoxic endpoints including echinocytes, acanthocytes, teardrop-like erythrocytes, microcytes and fused erythrocytes. Frequencies of these abnormalities were significantly different (p<0.05) in comparison to control group. The maximum number of MN, BN and most of NAs and MAEs were recorded in the 5th day of exposure and then start to decrease as recorded in the 7th day. Addition of the vitamin E alone to the diet significantly (p<0.05) decreased the frequencies of MN, BN, and most of NAs and MAEs to become less than those recorded in metals-treated fish. But, addition of a combination of Se with vitamins A, C and E in the diet resulted in more significant decrease (p<0.05) in frequencies of MN, BN, NAs and most MAEs to become less than those recorded in both, fish treated with metals only and fish treated with metals and supplied with vitamin E alone in the diet. Therefore, this study confirms the powerful protective potential of the vitamin E alone and a combination of SE with vitamins A, C and E as antioxidants against the genotoxicity and cytotoxicity of Cd, Cu, Pb and Zn in erythrocytes of O. niloticus. Also, confirmed on the validity of MN test and NAs in addition to MAEs as effective indicators and valuable sensitive monitoring tools for detecting genotoxic and cytotoxic agents in the aquatic environment.