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The United Nations World Drug Report published in 2022 alarmed that the global market of illicit drugs is steadily expanding in space and scale. Substances of abuse are usually perceived in the light of threats to human health and public security, while the environmental aspects of their use and subsequent emissions usually remain less explored. However, as with other human activities, drug production, trade, and consumption of drugs may leave their environmental mark. Therefore, this paper aims to review the occurrence of illicit drugs in surface waters and their bioaccumulation and toxicity in fish. Illicit drugs of different groups, i.e., psychostimulants (methamphetamines/amphetamines, cocaine, and its metabolite benzoylecgonine) and depressants (opioids: morphine, heroin, methadone, fentanyl), can reach the aquatic environment through wastewater discharge as they are often not entirely removed during wastewater treatment processes, resulting in their subsequent circulation in nanomolar concentrations, potentially affecting aquatic biota, including fish. Exposure to such xenobiotics can induce oxidative stress and dysfunction to mitochondrial and lysosomal function, distort locomotion activity by regulating the dopaminergic and glutamatergic systems, increase the predation risk, instigate neurological disorders, disbalance neurotransmission, and produce histopathological alterations in the brain and liver tissues, similar to those described in mammals. Hence, this drugs-related multidimensional harm to fish should be thoroughly investigated in line with environmental protection policies before it is too late. At the same time, selected fish species (e.g., Danio rerio , zebrafish) can be employed as models to study toxic and binge-like effects of psychoactive, illicit compounds.

Oxygen fluctuations are common in freshwater habitats and aquaculture and can impact ecologically and economically important species of fish like cyprinids. To gain insight into the physiological responses to oxygen fluctuations in two common cyprinid species, we evaluated the impact of short-term intermittent hypoxia on oxidative stress and metabolic parameters (including levels of prooxidants and oxidative lesions, antioxidants, mitochondrial enzyme activities, mitochondrial swelling, markers of apoptosis, autophagy and cytotoxicity) in silver carp Hypophthalmichthys molitrix and gibel carp Carassius gibelio. During hypoxia, gibel carp showed higher baseline levels of antioxidants and less pronounced changes in oxidative and metabolic biomarkers in the tissues than silver carp. Reoxygenation led to a strong shift in metabolic and redox-related parameters and tissue damage, indicating high cost of post-hypoxic recovery in both species. Species-specific differences were more strongly associated with oxidative stress status, whereas metabolic indices and nitrosative stress parameters were more relevant to the response to hypoxia-reoxygenation. Overall, regulation of energy metabolism appears more critical than the regulation of antioxidants in the response to oxygen deprivation in the studied species. Further research is needed to establish whether prioritizing metabolic over redox regulation during hypoxia-reoxygenation stress is common in freshwater cyprinids., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2023. Published by The Company of Biologists Ltd.)

Our research sought to determine the molecular and biochemical effects of environmentally relevant exposure to commonly used chloro-s-triazine herbicide terbuthylazine and organophosphate insecticide malathion on zebrafish. To this aim, mature zebrafish were exposed to 2 and 30 µg L -1 terbuthylazine and 5 and 50 µg L -1 malathion alone and in combination for 14 days. Aside from the accumulation of TBARS and protein carbonyls, a decrease in antioxidants and succinate dehydrogenase activity, an increase in oxidized glutathione, and enhanced apoptosis via Caspase-3 and BAX overexpression were observed. Furthermore, terbuthylazine and malathion induced mitochondrial swelling (up to 210% after single exposure and up to 470% after co-exposure) and lactate dehydrogenase leakage (up to 268% after single exposure and up to 570% after co-exposure) in a concentration-dependent manner. Significant upregulation of ubiquitin expression and increased cathepsin D activity were characteristics that appeared only upon terbuthylazine exposure, whereas the induction of IgM was identified as the specific characteristic of malathion toxicity. Meanwhile, no alterations in the zebrafish hypothalamic-pituitary-thyroid axis was observed. Co-exposure increased the adverse effects of individual pesticides on zebrafish. This study should improve the understanding of the mechanisms of pesticide toxicity that lead to fish impairment and biodiversity decline.

Global warming and human-induced eutrophication drive the occurrence of various cyanotoxins in aquatic environments. These metabolites reveal diversified mechanisms of action, encompassing cyto-, neuro-, hepato-, nephro-, and neurotoxicity, and pose a threat to aquatic biota and human health. In the present paper, we review data on the occurrence of the most studied cyanotoxins, microcystins, nodularins, cylindrospermopsin, anatoxins, and saxitoxins, in the aquatic environment, as well as their potential bioaccumulation and toxicity in fish. Microcystins are the most studied among all known cyanotoxins, although other toxic cyanobacterial metabolites are also commonly identified in aquatic environments and can reveal high toxicity in fish. Except for primary toxicity signs, cyanotoxins adversely affect the antioxidant system and anti-/pro-oxidant balance. Cyanotoxins also negatively impact the mitochondrial and endoplasmic reticulum by increasing intracellular reactive oxygen species. Furthermore, fish exposed to microcystins and cylindrospermopsin exhibit various immunomodulatory, inflammatory, and endocrine responses. Even though cyanotoxins exert a complex pressure on fish, numerous aspects are yet to be the subject of in-depth investigation. Metabolites other than microcystins should be studied more thoroughly to understand the long-term effects in fish and provide a robust background for monitoring and management actions.

Zinc oxide nanoparticles are released into marine environments from industrial, medical and consumer uses sparking concerns about their potential ecotoxicological effects. Ecological hazard assessment of nZnO in marine ecosystems is hindered by the lack of understanding of the potential interactive effects of nZnO toxicity with other common abiotic stressors, such as salinity fluctuations, in marine organisms. To close this gap in our knowledge, we carried out a comprehensive biomarker-based assessment of the combined effects of salinity and nZnO in a sentinel marine bivalve, the blue mussels Mytilus edulis. The mussels were exposed for 21 days to clean seawater (control), an environmentally relevant concentration (100 μg Zn l -1 ) of nZnO or dissolved Zn (to identify the toxic effects attributable to Zn 2+ toxicity) under the normal (15), low (5) and fluctuating (5-15) salinity regimes. The selected molecular and biochemical markers focused on the oxidative stress, apoptosis, detoxification system and inflammation in the gills and the digestive gland of the mussels. Biomarker analysis showed different effects of nZnO and dissolved Zn on biomarkers of oxidative stress, xenobiotic detoxification and apoptosis but similar effects of both pollutants on the levels of metallothioneins and inflammatory markers. Exposure to nZnO led to elevated levels of lipid peroxidation, upregulation of p53 and p38 stress kinases and apoptosis-related genes, most notably in the gills. Exposure to dissolved Zn led to accumulation of protein carbonyls and activated redox-sensitive detoxification enzymes (NADPH-P450 reductase and glutathione-S-transferase) in the mussels. The ambient salinity had significant effects the cellular adverse effects of nZnO in the mussels. The nZnO-induced cellular stress was detectable under the normal (15) and fluctuating (5-15) salinity conditions in the studied brackish water population of the mussels. At low salinity (5), nZnO toxicity signal was almost completely dampened. These findings indicate that chronic osmotic stress close to the tolerance limits of M. edulis prevails over the effects of the environmentally relevant nZnO and dissolved Zn concentrations in combined exposures. These stressor interactions might ameliorate the cellular toxicity of nZnO in the mussels but limit applicability of cellular stress biomarkers for detecting the toxic effects of nanopollutants in low salinity habitats., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Pharmaceutical pollution of water bodies is among the top-notch environmental health risks all over the world. The aim of the present study was to investigate the effects of two common pharmaceuticals namely ibuprofen and gemfibrozil on zebrafish at environmentally relevant concentrations. In zebrafish liver, gemfibrozil caused a decrease in glutathione and glutathione transferase and an increase in catalase but had no effect on lipid peroxidation and protein carbonylation. Ibuprofen altered the antioxidant defense system, promoted protein carbonylation in zebrafish liver, and increased vitellogenin-like protein in the blood. Ibuprofen and particularly gemfibrozil induced lysosomes biogenesis. Lactate dehydrogenase in the blood was also found to be higher in the studied groups. Studied pharmaceuticals did not affect complex II of the electron respiratory chain. Ibuprofen affects zebrafish health status more profoundly than gemfibrozil. Our results showed that pharmaceuticals even in low, environmentally realistic concentrations, induced profound changes in the stress-responsive systems of zebrafish., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Organic UV filters have emerged as a new threat to marine organisms, but ecotoxicological studies have so far focused on only a few substances despite the chemical diversity of these synthetic sunscreen agents. Here we examined the responses of blue mussels Mytilus edulis to ensulizole, a non-lipophilic UV filter commonly found in the Baltic Sea. Mussels were exposed for three weeks to five ensulizole concentrations of 10, 10 2 , 10 3 , 10 4 , and 10 5  ng/L. Stress on stress response was evaluated by subjecting mussels to air exposure. A battery of biomarkers related to detoxification and antioxidant defense, oxidative stress damage, energy reserves and metabolism, autophagy, apoptosis, inflammation, and DNA damage was measured in the gills and the digestive gland. In general, ensulizole affected the antioxidant response, energy storage, and cell death-related processes in mussel tissues. Mussels exposed to low, environmentally relevant concentrations of ensulizole had a shorter air survival time than the control. Ensulizole often showed the non-monotonic concentration-response curves, suggesting the complex effects of this UV filter at molecular, biochemical, and organismal levels., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The unprovoked aggression of Russian military forces on Ukraine in February 2022 has caused a high influx of refugees, including children, to neighboring countries, particularly Poland. This caused additional pressures on the healthcare system and the need to meet challenges for public health, such as those related to infectious diseases. Here, we discuss the potential epidemiological risks associated with the war-induced influx of refugees (coronavirus disease 2019, measles, pertussis, tetanus, and poliomyelitis) and highlight the need for their swift management through institutional support, educational campaigns, counteracting antiscience misinformation, and pursuing vaccinations of refugees but also improving or maintaining good levels of immunization in populations of countries welcoming them. These are necessary actions to avoid overlapping of war and infectious diseases and associated public health challenges., Competing Interests: Potential conflicts of interest. A. F. reports an unpaid position as President of the Polish Society of Public Health. All other authors report no potential conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Pesticides are well known for their high levels of persistence and ubiquity in the environment, and because of their capacity to bioaccumulate and disrupt the food chain, they pose a risk to animals and humans. With a focus on organophosphate and triazine pesticides, the present review aims to describe the current state of knowledge regarding spatial distribution, bioaccumulation, and mode of action of frequently used pesticides. We discuss the processes by which pesticides and their active residues are accumulated and bioconcentrated in fish, as well as the toxic mechanisms involved, including biological redox activity, immunotoxicity, neuroendocrine disorders, and cytotoxicity, which is manifested in oxidative stress, lysosomal and mitochondrial damage, inflammation, and apoptosis/autophagy. We also explore potential research strategies to close the gaps in our understanding of the toxicity and environmental risk assessment of organophosphate and triazine pesticides.

Agrochemicals can adversely affect biodiversity, environment and human health, and commonly occur in mixtures with poorly characterized toxic mechanisms and health hazards. Here, we evaluated the individual and mixture toxicities of Roundup and chlorpyrifos in environmentally relevant concentrations to zebrafish using molecular and biochemical indices. Studied pesticides alone and in combination caused depletion of total antioxidant capacity and cellular thiols, overproduction of ROS, accumulation of oxidative lesions and elevated DNA damage in zebrafish liver. Notably, low concentration of Roundup induced a hormesis-like effect by stimulating the protective cellular mechanisms. Chlorpyrifos showed stronger prooxidant effects than Roundup and additionally caused nitrosative and carbonyl stress in zebrafish. At the organismal level, studied pesticides and their mixtures induced hepato- and neurotoxicity. The effects of the studied pesticides on biomarkers of apoptosis, endocrine disruption and immune disorders were generally weak and inconsistent. The multibiomarker assessment showed that chlorpyrifos is considerably more toxic than Roundup to zebrafish. The toxic effects of the pesticide mixtures were mostly driven by chlorpyrifos, with minimal or mitigating effects of Roundup addition. These findings elucidate the toxic mechanisms of common pesticides in a model vertebrate and demonstrate that health hazards of pesticide mixtures cannot be predicted from the effects of single pesticides., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

This study aimed to compare the occurrence and nuisance of adverse events following administration of each COVID-19 vaccine dose between two groups: individuals given three doses of mRNA vaccine (homologous group, 3 × mRNA, n = 252) and those given two doses of adenoviral vector vaccine further boosted with mRNA vaccine (heterologous group, 2 × AZ + 1 × mRNA, n = 205). Although the studied groups differed significantly in the frequency and number of side effects after the first and second vaccine dose, no relevant differences were seen following the booster administration. Arm pain and fatigue were the most common effects, regardless of the vaccination group and vaccine dose. In the homologous group, female sex, lower BMI, and no history of regular influenza vaccination were associated with a higher frequency of side effects of a booster dose. In the heterologous group, the history of COVID-19 was associated with an increased number of side effects seen after a booster. In both groups, the number of side effects related to the first and second dose correlated with the number observed after administration of a booster dose. Individuals receiving a homologous booster reported a higher nuisance of side effects than the heterologous group. It was similar to the level reported after the second dose in both groups. The use of pharmaceuticals to counteract the side effects was more frequent after a first dose in the 2 × AZ + 1 × mRNA group, but higher after second dose in individuals receiving the 3 × mRNA vaccination scheme. The frequency of pharmaceutical use after a booster dose was similar in both groups (approx. 60%). Paracetamol was most frequently chosen, regardless of the group and vaccine dose. In addition, the vast majority of participants (93%) declared to accept future doses of the COVID-19 vaccine if their administration would be recommended. This study provides an overview of the response to homologous and heterologous mRNA vaccine booster dose that may be valuable in shaping accurate and honest communication with vaccinated individuals, especially in those regions which are yet to pursue booster strategies.

Adverse reactions after intravascular administration of iodine-based contrast media are well-known. Nevertheless the same type of contrast media is also used for endoscopic retrograde cholangiopancreatography and systemic absorption of contrast media after mentioned procedure routinely occurs, not much is known about effects of widely used diatrizoates (Triombrast) on the hepato-pancreato-biliary system in case of cholelithiasis treatment., Aim: The aim of the present study was to determine the effectiveness and biosafety of diatrizoate contrast media in terms of complicated cholelithiasis healing using conventional and improved surgery treatment protocols based on set of biochemical markers., Materials and Methods: The paper presents materials of clinical observation and biochemical analysis of 122 patients have been diagnosed with gallstone disease complicated by choledocholithiasis and cholangitis and biliary pancreatitis. Biochemical liver tests before and after surgery treatment using conventional and improved protocols were determined., Results: Biochemical manifestations of hepatocellular injury included exceeded activity of γ-glutamyltranspeptidase and aminotrasferases as well as level of liver fatty acid-binding protein and bilirubin which were different between groups of patients with cholelithiasis who suffered from concomitant cholangitis and pancreatitis. Proposed management algorithm for patients with gallstone disease with concomitant cholangitis and pancreatitis links to get rid of endoscopic retrograde cholangiography with contrast agent from the conventional surgery treatment protocols because its most obvious downside., Conclusions: Patients with gallstone diseases revealed significant biochemical changes that should be successfully resolved after surgery treatment without endoscopic retrograde cholangio- pancreatography with contrast media because its hepatotoxic effect., (© 2022 MEDPRESS.)

The use of glyphosate-based Roundup and triazine herbicide Atrazine has increased markedly in last decades. Thus, it is important to evaluate toxic effects of these herbicides to non-targeted organisms such as zooplankton to understand their safety toward aquatic ecosystems. In the current study, we performed Daphnia toxicity tests based on lethality to identify LC 50 that provides acute aquatic toxicity classification criteria. LC 50 for Roundup exposure for 24 hours was found to be 0.022 mg/L and 48 hours - 0.0008 mg/L. Atrazine showed LC 50 at concentrations of 40 mg/L and 7 mg/L for 24 and 48 hours, respectively. We demonstrated that exposure to ecologically relevant concentrations of Roundup or Atrazine decreases lipid peroxidation and protein thiol levels, however caused increase in carbonyl protein and low-molecular-weight thiols content. Moreover, the herbicide treatments caused increase of superoxide dismutase activity. Our data suggest that at very low concentrations Roundup and Atrazine disturb free radical processes in D. magna ., (Copyright © 2022 Husak et al.)

The global occurrence of organic UV filters in the marine environment is of increasing ecotoxicological concern. Here we assessed the toxicity of UV filters ensulizole and octocrylene in the blue mussels Mytilus edulis exposed to 10 or 100 μg l -1 of octocrylene and ensulizole for two weeks. An integrated battery of biochemical and molecular biomarkers related to xenobiotics metabolism and cellular toxicity (including oxidative stress, DNA damage, apoptosis, autophagy and inflammation) was used to assess the toxicity of these UV filters in the mussels. Octocrylene (but not ensulizole) accumulated in the mussel tissues during the waterborne exposures. Both studied UV filters induced sublethal toxic effects in M. edulis at the investigated concentrations. These effects involved induction of oxidative stress, genotoxicity (indicated by upregulation of DNA damage sensing and repair markers), upregulation of apoptosis and inflammation, and dysregulation of the xenobiotic biotransformation system. Octocrylene induced cellular stress in a concentration-dependent manner, whereas ensulizole appeared to be more toxic at the lower (10 μg l -1 ) studied concentration than at 100 μg l -1 . The different concentration-dependence of sublethal effects and distinct toxicological profiles of ensulizole and octocrylene show that the environmental toxicity is not directly related to lipophilicity and bioaccumulation potential of these UV filters and demonstrate the importance of using bioassays for toxicity assessment of emerging pollutants in coastal marine ecosystems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Engineered nanoparticles including ZnO nanoparticles (nZnO) are important emerging pollutants in aquatic ecosystems creating potential risks to coastal ecosystems and associated biota. The toxicity of nanoparticles and its interaction with the important environmental stressors (such as salinity variation) are not well understood in coastal organisms and require further investigation. Here, we examined the interactive effects of 100 μg l -1 nZnO or dissolved Zn (as a positive control for Zn 2+ release) and salinity (normal 15, low 5, and fluctuating 5-15) on bioenergetics and intermediate metabolite homeostasis of a keystone marine bivalve, the blue mussel Mytilus edulis from the Baltic Sea. nZnO exposures did not lead to strong disturbances in energy or intermediate metabolite homeostasis regardless of the salinity regime. Dissolved Zn exposures suppressed the mitochondrial ATP synthesis capacity and coupling as well as anaerobic metabolism and modified the free amino acid profiles in the mussels indicating that dissolved Zn is metabolically more damaging than nZnO. The environmental salinity regime strongly affected metabolic homeostasis and altered physiological and biochemical responses to nZnO or dissolved Zn in the mussels. Exposure to low (5) or fluctuating (5-15) salinity affected the physiological condition, energy metabolism and homeostasis, as well as amino acid metabolism in M. edulis. Generally, fluctuating salinity (5-15) appeared bioenergetically less stressful than constantly hypoosmotic stress (salinity 5) in M. edulis indicating that even short (24 h) periods of recovery might be sufficient to restore the metabolic homeostasis in this euryhaline species. Notably, the biological effects of nZnO and dissolved Zn became progressively less detectable as the salinity stress increased. These findings demonstrate that habitat salinity must be considered in the biomarker-based assessment of the toxic effects of nanopollutants on coastal organisms., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The global increase in cyanobacterial blooms poses environmental and health threats. Selected cyanobacterial strains reveal toxicities despite a lack of synthesis of known toxic metabolites, and the mechanisms of these toxicities are not well understood. Here we investigated the toxicity of non-cylindrospermopsin and non-microcystin producing Aphanizomenon gracile and Raphidiopsis raciborskii of Central European origin to zebrafish exposed for 14 days to their extracts. Toxicological screening revealed the presence of anabaenopeptins and a lack of anatoxin-a, ß-methylamino-L-alanine or saxitoxins in examined extracts. The responses were compared to 20 μg L -1 of common cyanobacterial toxins cylindrospermopsin (CYN) and microcystin-LR (MC-LR). The expression of the marker genes involved in apoptosis (caspase 3a and 3b, Bcl-2, BAX, p53, MAPK, Nrf2), DNA damage detection and repair (GADD45, RAD51, JUN, XPC), detoxification (CYP1A, CYP26, EPHX1), lipid metabolism (PPARa, FABP1, PLA2), phosphorylation/dephosphorylation (PPP6C, PPM1) and cytoskeleton (actin, tubulin) were examined using targeted transcriptomics. Cellular stress and toxicity biomarkers (oxidative injury, antioxidant enzymes, thiol pool status, and lactate dehydrogenase activity) were measured in the liver, and acetylcholinesterase activity was determined as an index of neurotoxicity in the brain. The extracts of three cyanobacterial strains that produce no known cyanotoxins caused marked toxicity in D. rerio, and the biomarker profiles indicate different toxic mechanisms between the bioactive compounds extracted from these strains and the purified cyanotoxins. All studied cyanobacterial extracts and purified cyanotoxins induced oxidative stress and neurotoxicity, downregulated Nrf2 and CYP26B1, disrupted phosphorylation/dephosphorylation processes and actin/tubulin cytoskeleton and upregulated apoptotic activity in the liver. The tested strains and purified toxins displayed distinctively different effects on lipid metabolism. Unlike CYN and MC-LR, the Central European strain of A. gracile and R. raciborskii did not reveal a genotoxic potential. These findings help to further understand the ecotoxicological consequences of toxic cyanobacterial blooms in freshwater ecosystems., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver with a very poor prognosis and constantly growing incidence. Among other primary risks of HCC, metabolic disorders and obesity have been extensively investigated over recent decades. The latter can promote nonalcoholic fatty liver disease (NAFLD) leading to the inflammatory form of nonalcoholic steatohepatitis (NASH), that, in turn, promotes HCC. Molecular determinants of this pathogenic progression, however, remain largely undefined. In this study, we have focussed on the investigation of α-dicarbonyl compounds (α-dC), highly reactive and tightly associated with overweight-induced metabolic disorders, and studied their potential role in NAFLD and progression toward HCC using murine models. NAFLD was induced using high-fat diet (HFD). Autochthonous HCC was induced using transposon-based stable intrahepatic overexpression of oncogenic NRAS G12V in mice lacking p19 Arf tumor suppressor. Our study demonstrates that the HFD regimen and HCC resulted in strong upregulation of α-dC in the liver, heart, and muscles. In addition, an increase in α-dC was confirmed in sera of NAFLD and NASH patients. Furthermore, higher expression of the receptor for advanced glycation products (RAGE) was detected exclusively on immune cells and not on stroma cells in livers of mice with liver cancer progression. Our work confirms astable interplay of liver inflammation, carbonyl stress mediated by α-dC, and upregulated RAGE expression on CD8 + Tand natural killer (NK) cells in situ in NAFLD and HCC, as key factors/determinants in liver disease progression. The obtained findings underline the role of α-dC and RAGE + CD8 + Tand RAGE + NK cells as biomarkers and candidates for a local therapeutic intervention in NAFLD and malignant liver disease., Competing Interests: The authors report no conflict of interest. H.W. is a consultant by Bayer, Eisai, MSD and Roche, H.W. is a clinical trial investigator by Bayer and Roche., (© 2021 The Author(s). Published with license by Taylor & Francis Group, LLC.)

Gastropod mollusks have achieved an eminent importance as biological indicators of environmental quality. In the present study, we applied a multibiomarker approach to evaluate its applicability for the pond snail Lymnaea stagnalis, exposed to common industrial and agricultural pollutants at environmentally relevant concentrations. The snails were exposed to copper (Cu 2+ , 10 µg L -1 ), zinc (Zn 2+ , 130 µg L -1 ), cadmium (Cd 2+ , 15 µg L -1 ), or the thiocarbamate fungicide "Tattoo" (91 µg L -1 ) during 14 days. Metal treatment and exposure to "Tattoo" caused variable patterns of increase or decrease of metal levels in the digestive gland, with a clear accumulation of only Cd and Zn after respective metal exposure. Treatment with Cu and "Tattoo" caused an increase of cytochrome P450-related EROD activity. Glutathione S-transferase was inhibited by exposure to Cu, Zn, and "Tattoo." Treatment with the "Tattoo" led to an inhibition of cholinesterase activity, whereas Cu and Cd increased its activity. Caspase-3 activity was enhanced by up to 3.3 times in all treatments. A nearly uniform inhibitory effect for oxidative stress response parameters was observed in all kinds of exposure, revealing an inhibition of superoxide dismutase (Mn-SOD) activity, a depression of glutathione (GSH and GSSG) and of protein carbonyl levels. Pollutant-specific effects were observed for the catalase activity, superoxide anion production, and lipid peroxidation levels. Due to the high response sensitivity of Lymnaea stagnalis to chemical impacts, we suggest our study as a contribution for biomarker studies with this species under field conditions.

Toxicity of cyanobacteria is the subject of ongoing research, and a number of toxic metabolites have been described, their biosynthesis pathways have been elucidated, and the mechanism of their action has been established. However, several knowledge gaps still exist, e.g., some strains produce hitherto unknown toxic compounds, while the exact dynamics of exerted toxicity during cyanobacterial growth still requires further exploration. Therefore, the present study investigated the toxicity of extracts of nine freshwater strains of Aphanizomenon gracile , an Aphanizomenon sp. strain isolated from the Baltic Sea, a freshwater strain of Planktothrix agardhii , and two strains of Raphidiopsis raciborskii obtained from 25- and 70-day-old cultures. An in vitro experimental model based on Cyprinus carpio hepatocytes (oxidative stress markers, DNA fragmentation, and serine/threonine protein activity) and brain homogenate (cholinesterase activity) was employed. The studied extracts demonstrated toxicity to fish cells, and in general, all examined extracts altered at least one or more of considered parameters, indicating that they possess, to some degree, toxic potency. Although the time from which the extracts were obtained had a significant importance for the response of fish cells, we observed strong variability between the different strains and species. In some strains, extracts that originated from 25-day-old cultures triggered more harmful effects on fish cells compared to those obtained from 70-day-old cultures, whereas in other strains, we observed the opposite effect or a lack of a significant change. Our study revealed that there was no clear or common pattern regarding the degree of cyanobacterial bloom toxicity at a given stage of development. This means that young cyanobacterial blooms that are just forming can pose an equally toxic threat to aquatic vertebrates and ecosystem functioning as those that are stable or old with a tendency to collapse. This might be largely due to a high variability of strains in the bloom.

ZnO nanoparticles (nZnO) are released into the coastal environment from multiple sources, yet their toxicity to marine organisms is not well understood. We investigated the interactive effects of salinity (normal 15, low 5, and fluctuating 5-15) and nZnO (100 μg l - 1 ) on innate immunity of the blue mussels Mytilus edulis from a brackish area of the Baltic Sea. Exposure to ionic Zn (100 μg l - 1 ) was used to test whether the toxic effects of nZnO can be attributed to the potential release of Zn 2+ . Functional parameters and the expression of key immune-related genes were investigated in the mussels exposed to nZnO or ionic Zn under different salinity regimes for 21 days. nZnO exposures elevated hemocyte mortality, suppressed adhesion, stimulated phagocytosis, and led to an apparent increase in lysosomal volume. At salinity 15, nZnO suppressed the mRNA expression of the Toll-like receptors TLRb and c, C-lectin, and the complement system component C3q indicating impaired ability for pathogen recognition. In contrast, the mRNA levels of an antimicrobial peptide defensin increased during nZnO exposure at salinity 15. At fluctuating salinity (5-15), nZnO exposure increased expression of multiple immune-related genes in hemocytes including the complement system components C1 and C3q, and the Toll-like receptors TLRa, b and c. Low salinity (5) had strong immunosuppressive effects on the functional and molecular immune traits of M. edulis that overshadowed the effects of nZnO. The salinity-dependent modulation of immune response to nZnO cannot be attributed to the differences in the aggregation or solubility of nZnO, and likely reflects the interaction of the toxic effects of nanoparticles and physiological effects of the osmotic stress. These findings have implications for the environmental risk assessment of nanomaterials and the development of the context-specific biomarker baselines for coastal pollution monitoring., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Marine benthic invertebrates are frequently exposed to fluctuating oxygen levels resulting in hypoxia-reoxygenation (H/R) stress in the intertidal, estuarine and shallow coastal habitats. H/R stress can strongly affect the organisms' physiological performance due to the negative shifts in bioenergetics and redox balance. H/R stress commonly leads to the depletion of energy substrates and accumulation of anaerobic end products, but the effects of H/R stress on the homeostasis of the intermediate nitrogenous compounds are not well understood. We studied the effects of the short-term and long-term hypoxia (1 and 6 days, respectively) and subsequent reoxygenation on the metabolite profiles of free amino acids (FAAs), as well as the intermediates of the urea cycle and purine metabolism in two species of hypoxia-tolerant intertidal bivalves, the blue mussels Mytilus edulis and the Pacific oysters Crassostrea gigas. Accumulation of succinate was assessed to determine the role of anaerobiosis in the metabolic responses to H/R stress. Our study showed that the more hypoxia-tolerant of the two studied species (C. gigas) had lower rate of succinate accumulation during hypoxia (indicating stronger metabolic rate suppression) and was better able to maintain the homeostasis of nitrogenous intermediates during H/R stress compared with the less hypoxia-tolerant M. edulis. Furthermore, analysis of the metabolite profiles indicate that the oysters maintain high levels of cytoprotective compounds (such as taurine and GABA), accumulate lower levels of potential prooxidants (such as succinate and hypoxanthine) and experience less damage to oxidation-prone thiol-containing amino acids such as cysteine, homocysteine and methionine during hypoxia and reoxygenation compared with the blue mussels. This study indicates a potentially important role of intermediate metabolite homeostasis in the tolerance to prolonged hypoxia and H/R stress in marine organisms and opens avenue for further testing of this hypothesis in a broader comparative framework., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Hypoxia is a major stressor in estuarine and coastal habitats, leading to adverse effects in aquatic organisms. Estuarine bivalves such as blue mussels ( Mytilus edulis ) and Pacific oysters ( Crassostrea gigas ) can survive periodic oxygen deficiency but the molecular mechanisms that underlie cellular injury during hypoxia-reoxygenation are not well understood. We examined the molecular markers of autophagy, apoptosis and inflammation during short-term (1 day) and long-term (6 days) hypoxia and post-hypoxic recovery (1 h) in mussels and oysters by measuring the lysosomal membrane stability, activity of a key autophagic enzyme (cathepsin D) and mRNA expression of the genes involved in the cellular survival and inflammation, including caspase 2, 3 and 8, Bcl-2, BAX, TGF-β-activated kinase 1 (TAK1), nuclear factor kappa B1 (NF-κB) and NF-κB activating kinases IKKα and TBK1. Crassostrea gigas exhibited higher hypoxia tolerance, as well as blunted or delayed inflammatory and apoptotic response to hypoxia and reoxygenation as shown by the later onset and/or the lack of transcriptional activation of caspases, BAX and the inflammatory effector NF-κB, compared with M. edulis Long-term hypoxia resulted in upregulation of Bcl-2 in the oysters and mussels, implying activation of anti-apoptotic mechanisms. Our findings indicate the potential importance of the cell survival pathways in hypoxia tolerance of marine bivalves, and demonstrate the utility of the molecular markers of apoptosis and autophagy for the assessment of sublethal hypoxic stress in bivalve populations., Competing Interests: Competing interestsThe authors declare no competing or financial interests., (© 2020. Published by The Company of Biologists Ltd.)

Selected species of cyanobacteria and green algae have been reported to produce lipophilic polymethoxy-1-alkenes (PMAs) which were shown to exhibit in vivo teratogenicity. Considering that information on PMAs in Arthospira sp. (known commercially as Spirulina) and Chlorella sp. cultivated for food supplement production was essentially lacking, the present study screened Chlorella (n = 10) and Spirulina (n = 13) food supplements registered in the European Union. Mass spectrometry analysis of column fractionated extracts was performed. None of the four variants previously reported in some cyanobacteria and green algae, nor any potentially related structures were detected in the studied samples. Since the isolated lipophilic fractions contained various compounds, they were further screened for in vivo teratogenicity in Danio rerio embryo, and for the potential to induce oxidative stress and genotoxicity in the liver and neurotoxicity in the brain of adult zebrafish. None of the tested food supplements had detectable levels of PMAs or any potentially related structures. No teratogenicity was revealed except for spinal curvature induced by fractions obtained from two Chlorella products. Selected fractions revealed cytotoxicity as indicated by an increased level of reactive oxygen species, catalase activity, lipid peroxidation and increased frequency of DNA strand breaks in hepatic tissue. The majority (60%) of Chlorella fractions induced an increase in cholinesterase activity in zebrafish brain homogenate while exposure to 61.5% of Spirulina fractions was associated with its decrease. The present study confirms that Chlorella and Spirulina food supplements are free of teratogenic PMAs, although the observed in vivo toxicities raise questions regarding the quality of selected products., Competing Interests: The authors declare no conflict of interest.

Biofouling causes massive economical losses in the maritime sector creating an urgent need for effective and ecologically non-harmful antifouling materials. Zinc oxide (ZnO) nanorod coatings show promise as an antifouling material; however, the toxicity of ZnO nanorods to marine organisms is not known. We compared the toxicity of suspended ZnO nanorods (NR) with that of ZnO nanoparticles (NP) and ionic Zn 2+ in a marine bivalve Mytilus edulis exposed for two weeks to 10 or 100 μg Zn L -1 of ZnO NPs, NRs or Zn 2+ , or to immobilized NRs. The multi-biomarker assessment included bioenergetics markers (tissue energy reserves, activity of mitochondrial electron transport system and autophagic enzymes), expression of apoptotic and inflammatory genes, and general stress biomarkers (oxidative lesions, lysosomal membrane stability and metallothionein expression). Exposure to ZnO NPs, NRs and Zn 2+ caused accumulation of oxidative lesions in proteins and lipids, stimulated autophagy, and led to lysosomal membrane destabilization indicating toxicity. However, these responses were not specific for the form of Zn (NPs, NR or Zn 2+ ) and showed no monotonous increase with increasing Zn concentrations in the experimental exposures. No major disturbance of the energy status was found in the mussels exposed to ZnO NPs, NRs, or Zn 2+ . Exposure to ZnO NPs and NRs led to a strong induction of apoptosis- and inflammation-related genes, which was not seen in Zn 2+ exposures. Based on the integrated biomarker response, the overall toxicity as well as the pro-apoptotic and pro-inflammatory action was stronger in ZnO NPs compared with the NRs. Given the stability of ZnO NR coatings and the relatively low toxicity of suspended ZnO NR, ZnO NR coating might be considered a promising low-toxicity material for antifouling paints., (Copyright © 2019 Elsevier B.V. All rights reserved.)

However the physiological stress in aquatic organisms associated with hydropower plants (HPP) ecosystems has been previously investigated, no studies have so far assessed it on biochemical level. Therefore this study evaluated an oxidative stress and toxicity in the gibel carp Carassius auratus gibelio associated with a small-scale HPP in the West Ukraine. A battery of liver, brain and blood markers was evaluated individuals inhabiting upstream and downstream of the dam of the small-scale Kasperivtci HPP (KHPP; an installed capacity of 7.5 MW), and from a reference site. Number of alterations were noted in fish from the KHPP impoundment facility including signs of oxidative stress (a decrease in superoxide dismutase (SOD) activity and an increase in protein carbonyls) and cytotoxicity (an increase in micronucleated erythrocytes and caspase-3 activity). No changes in DNA fragmentation in hepatocytes or brain cholinesterase activity were detected. As demonstrated by the integral stress index, fish associated with downstream of the dam revealed the greatest alterations reflected by the combined oppression of antioxidant system (SOD, catalase) and pro-oxidants (thiobarbituric acid reactive substances and oxyradicals), low concentration of metallothioneins, but high cathepsin D activity (as markers of lysosomal dysfunction and autophagy) and increased vitellogenin concentration in males (indicating an endocrine disruption). The study highlights that fish inhabiting ecosystems associated with HPP, particularly downstream of the dam, may face additional stresses with long-term effects yet to be evaluated., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Cylindrospermopsin (CYN) is an alkaloid biosynthesized by selected cyanobacteria, the cyto- and genotoxic properties of which have been studied extensively by in vitro and in vivo experimental models. Various studies have separately established the role of uracil, guanidine and hydroxyl groups in CYN-induced toxicity. In the present study, we have prepared five synthetic analogues that all possess a uracil group but had variations in the other functionality found in CYN. We compared the in vitro toxicity of these analogues in common carp hepatocytes by assessing oxidative stress markers, DNA fragmentation and apoptosis. All the analogues tested induced generation of reactive oxygen species, lipid peroxidation (LPO) and DNA fragmentation. However, the greatest increase in LPO and increase in caspase-3 activity, an apoptosis marker, was demonstrated by an analogue containing guanidine, hydroxyl and uracil functionalities similar to those found in CYN but lacking the complex tricyclic structure of CYN. We also report a crystal structure of an analogue lacking the hydroxyl group found in CYN which does not show intramolecular H-bonding interactions between the guanidine and the uracil functionalities. The observations made in this work supports the hypothesis that CYN toxicity is a result of an interplay between both of the uracil, hydroxyl and guanidine functional groups., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Multiple interactions between different pollutants in the surface waters can cause unpredictable consequences. The aim of the study was to evaluate the combined effect of two widespread xenobiotics, titanium oxide nanoparticles (TiO 2 ) and bisphenol A (BPA), on freshwater bivalve Unio tumidus. The specimens were exposed for 14 days to TiCl 4 (Ti, 1.25 µM), TiO 2 (1.25 μM), BPA (0.88 nM), or their combination (TiO 2  + BPA). Every type of exposure resulted in a particular oxidative stress response: TiO 2 had antioxidant effect, decreasing the generation of reactive oxygen species (ROS) and phenoloxidase (PhO) activity, and doubling reduced glutathione (GSH) concentration in the digestive gland; Ti caused oxidative changes by increasing levels of ROS, PhO and superoxide dismutase; BPA decreased the GSH level by a factor of two. In the co-exposure treatment, these indices as well as lysosomal membrane stability were not affected. All Ti-containing exposures caused elevated levels of metalated metallothionein (Zn,Cu-MT), its ratio to total metallothionein protein, and lactate/pyruvate ratio. Both BPA-containing exposures decreased caspase-3 activity. All exposures, and particularly co-exposure, up-regulated CYP450-dependent oxidation, lipid peroxidation and lipofuscin accumulation, lysosomal cathepsin D and its efflux, as well as alkali-labile phosphates in gonads and caused DNA instability (except for TiO 2 ). To summarize, co-exposure to TiO 2  + BPA produced an overlap of certain individual responses but strengthened the damage. Development of water purification technologies using TiO 2 requires further studies of the biological effects of its mixtures. U. tumidus can serve as a sentinel organism in such studies.

Background and objectives: toxic liver injury results in nitrooxidative stress. Melatonin is a potent free radical scavenger, an inducible nitric oxide synthase (iNOS) inhibitor and an activator of antioxidant enzymes. The aim of this study was to investigate the hepatoprotective effect of exogenous melatonin on animals with acute toxic hepatitis. Material and m ethods: 36 healthy Sprague-Dawley male rats were split into three equal groups and given carbon tetrachloride (CCl 4 ), 2 g/kg (CCl 4 group) or the same dose of CCl 4 and melatonin, 10 mg/kg (CCl 4 /melatonin group) or saline (control group). The effect of melatonin on prooxidant and antioxidant system indexes, NO and NOS levels in serum and liver, data of mitochondrial chain functions and cytolysis in liver were evaluated in all three groups. Results: melatonin significantly decreased activities of AST, ALT, ceruloplasmine and thiobarbituric acid reactive substance (TBARS) in serum. Catalase activity was lowered in serum but not in the liver. Hepatic TBARS, lipid hydroperoxides and glutathione concentrations were decreased, while superoxide dismutase, mitochondrial cytochrome oxidase and succinate dehydrogenase activities increased. Melatonin inhibited synthesis of stable NO metabolites in serum: NO 2 -by 37.9%; NO 3 -by 29.2%. There was no significant difference in content NO 2 -in the liver, but concentration of NO 3 -increased by 32.6%. Melatonin significantly reduced iNOS concentrations both in serum (59.7%) and liver (57.8%) but did not affect endothelial isoform enzyme activities neither in serum, nor in liver. The histopathological liver lesions observed in the CCl 4 /melatonin group were less severe than those seen in the CCl 4 group. Conclusions: we demonstrated an ameliorating effect of melatonin on prooxidants and antioxidants, NO-NOS systems balance, mitochondrial function and histopathological lesions in the liver in rats with CCl 4 -induced hepatitis., Competing Interests: The authors declare no conflict of interest.

Biologically active compounds from pharmaceuticals cause concern due to their common occurrence in water and sediments of urbanized coasts and potential threat to marine organisms. Atorvastatin (ATO), a globally prescribed drug, is environmentally stable and bioavailable to marine organisms; however, the physiological and toxic effects of this drug on ecologically important coastal species are yet to be elucidated. We studied the effect of ATO (˜1.2 μg L -1 ) on bioenergetics (including whole-organism and mitochondrial respiration, as well as tissue energy reserves and mRNA expression of genes involved in mitochondrial biogenesis and fatty acid metabolism in the gills and the digestive gland) of a keystone bivalve Mytulis edulis (the blue mussel) from the Baltic Sea. Xenobiotic detoxification systems including activity and mRNA expression of P-glycoprotein, and Phase I and II biotransformation enzymes (cytochrome P450 monooxygenase CYP1A and glutathione transferase, GST) were also assessed in the gill and digestive gland of the mussels. Exposure to ATO caused rapid uptake and biotransformation of the drug by the mussels. Standard metabolic rate of ATO-exposed mussels increased by 56% indicating higher maintenance costs, yet no changes were detected in the respiratory capacity of isolated mitochondria. ATO exposure led to ˜60% decrease in the lysosomal membrane stability of hemocytes and ˜3-fold decrease in the whole-organism P-glycoprotein-driven and diffusional efflux of xenobiotics indicating altered membrane properties. The digestive gland was a major target of ATO toxicity in the mussels. Exposure of mussels to ATO led to depletion of lipid, carbohydrate and protein pools, and suppressed transcription of key enzymes involved in mitochondrial biogenesis (peroxisome proliferator-activated receptor gamma coactivator 1-alpha PGC-1α) and fatty acid metabolism (acetyl-CoA carboxylase and CYP4Y1) in the digestive gland. No bioenergetic disturbances were observed in the gills of ATO-exposed mussels, and elevated GST activity indicated enhanced ATO detoxification in this tissue. These data demonstrate that ATO can act as a metabolic disruptor and chemosensitizer in keystone marine bivalves and warrant further investigations of statins as emerging pollutants of concern in coastal marine ecosystems., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Global decline of amphibian populations causes particular concern about their vulnerability to novel environmental pollutants, including engineering nanomaterials and pharmaceutical products. We evaluated the bioavailability of nanoform of zinc oxide (n-ZnO) in frog Pelophylax ridibundus and determined whether co-exposure to a common pharmaceutical, a calcium-channel blocker nifedipine (Nfd) can affect this bioavailability. Male frogs were exposed for 14 days to the tap water (Control) and n-ZnO (3.1 μM), Zn 2+ (3.1 μM, as a positive control for n-ZnO exposures), Nfd (10 μM), and combination of n-ZnO and Nfd (n-ZnO + Nfd) in environmentally-relevant concentration. Exposure to Zn 2+ or n-ZnO led to up-regulation of metal-binding proteins, metallothioneins (MTs) in the liver and Zn-carrying vitellogenin-like proteins in the blood plasma. Notably, upregulation of MTs by Zn 2+ or n-ZnO exposures combined with increased binding of Zn and Cu to MTs. This was associated with the more reducing conditions in the liver tissue indicated by elevated lactate to pyruvate ratio. Nfd suppressed the binding of Zn and Cu to MTs and led to a decrease in Lactate/Pyruvate ratio and elevated protein carbonylation indicating pro-oxidant conditions. Redox status parameters were not directly related to DNA fragmentation, nuclear abnormalities or suppression of cholinesterase activity indicating that factors other than oxidative stress are involved in cytotoxicity of different pollutants and their combinations. Furthermore, activity of Phase I biotransformation enzyme (CYP450 oxidase measured as EROD) was elevated in Nfd-containing exposures and in Zn 2+ exposed frogs. Tyrosinase-like activity in the frog liver was strongly stimulated by Zn 2+ but suppressed by n-ZnO, Nfd and n-ZnO + Nfd. These findings show that Nfd modulates homeostasis of essential metals in amphibians and emphasize that physiological consequences of combined n-ZnO and Nfd exposures are difficult to predict based on the mechanisms of single stressors.

Bivalves from the cooling reservoirs of electrical power plants (PP) are exposed to the chronic heating and chemical pollution making them a suitable model to study the combined effects of these stressors. We investigated the effect of in situ exposures to chemical and thermal pollution in the PP cooling ponds on the metabolic responses of unionid bivalves (Unio tumidus) to a novel widespread pollutant, ZnO nanoparticles (nZnO). Male U. tumidus from the reservoirs of Dobrotvir and Burshtyn PPs (DPP and BPP) were maintained in clean water at 18 °C, or exposed for 14 days to one of the following conditions: nZnO (3.1 μM) or Zn 2+ (3.1 μM, a positive control for Zn impacts) at 18 °C, elevated temperature (T, 25 °C), or nZnO at 25 °C (nZnO + T). Baseline levels of glycogen, lipids and ATP were similar in the two studied populations, whereas the levels of proteins, lactate/pyruvate ratio (L/P) and extralysosomal cathepsin D level were higher in the tissues of BPP mussels. The levels of glycogen and glucose declined in most experimental exposures indicating elevated energy demand except for a slight increase in the digestive gland of warming-exposed BPP mussels and in the gills of the nZnO + T-exposed DPP-mussels. Experimental exposures stimulated cathepsin D activity likely reflecting onset of autophagic processes to compensate for stress-induced energy demand. No depletion of ATP in Zn-containing exposures was observed indicating that the cellular metabolic adjustments were sufficient for such compensation. Unexpectedly, experimental warming mitigated most metabolic responses to nZnO in co-exposures. Our data thus indicate that metabolic effects of nZnO strongly depend on the environmental context of the mussels (such as temperature and acclimation history) which must be taken into account for the molecular and cellular biomarker-based assessment of the nanoparticle effects in the field., (Copyright © 2018 Elsevier B.V. All rights reserved.)

As yet European strains of Raphidiopsis raciborskii (previously Cylindrospermopsis raciborskii) have not been found to produce known cyanotoxins although their extracts have caused adverse effects in mammals, as shown using in vitro and in vivo experimental models. The present study investigated whether R. raciborskii isolated from Western Poland and Ukraine can affect fish cells using in vitro exposures of hepatocytes and red blood cells (RBC), and brain homogenates obtained from common carp (Cyprinus carpio) to 1.0% and 0.1% extracts of 7 strains. The studied extracts evoked different responses of catalase activity in hepatocytes with both increase and decrease observed under low and high concentrations. The cellular thiol pool was also altered with most extracts inducing a decrease in the activity of glutathione-S-transferase, and Ukrainian strains leading to an increase in glutathione level and a decrease in metallothionein content. All the studied extracts induced comparable reactive oxygen species formation, lipid peroxidation, protein carbonylation and DNA fragmentation in hepatocytes, and all but one increased the activity of caspase-3. Only one extract caused lysosomal membrane destabilization as measured by neutral red retention in RBC. In contrast to extracts of Ukrainian isolates, exposure of brain homogenates to extracts of Polish strains induced an increase in acetylcholinesterase activity suggesting the neurotoxic action of their exudates. The results indicate that both Polish and Ukrainian strains of R. raciborskii may pose a toxicological risk to freshwater fish, and further, that Polish strains may produce compound(s) evoking neurotoxic effects., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The occurrence of cyanobacteria in freshwaters attracts much attention due to its associated health threats and ecological implications. Yet data on the composition of cyanobacteria taxa and toxigenicity in some regions is still scarce. Here, we explored the occurrence of cyanobacteria and cyanotoxins in three locations in Ukraine (reservoir for Kasperivtsi Hydrothermal Power Plant and outflowing River Seret, and cooling pond of Khmelnytsky Atomic Power Plant) in summer 2017. Cyanobacteria were a dominant fraction at all stations. A number of potent-toxin producers were identified including Cylindrospermopsis raciborskii, Aphanizomenon gracile, Dolichospermum flos-aquae, and Planktothrix agardhii. Screening for the presence of dissolved and particulate content of microcystins (-LR, -YR, and -RR), cylindrospermopsin, and anatoxin-a yielded negative results. The studied waters displayed no toxicity in human platelets in vitro. Further toxicological and ecological studies are necessary to evaluate the potential presence of cyanotoxin producers in Ukraine.

Bivalve mollusks from the cooling reservoirs of fuel power plants (PP) are acclimated to the chronic heating and chemical pollution. We investigated stress responses of the mussels from these ponds to determine their tolerance to novel environmental pollutant, zinc oxide nanoparticles (nZnO). Male Unio tumidus from the reservoirs of Dobrotvir and Burschtyn PPs (DPP and BPP), Ukraine were exposed for 14 days to nZnO (3.1 μM), Zn 2+ (3.1 μM) at 18 °C, elevated temperature (T, 25 °C), or nZnO at 25 °C (nZnO + T). Control groups were held at 18 °C. Zn-containing exposures resulted in the elevated concentrations of total and Zn-bound metallothionein (MT and Zn-MT) in the digestive gland, an increase in the levels of non-metalated MT (up to 5 times) and alkali-labile phosphates and lysosomal membrane destabilization in hemocytes. A common signature of nZnO exposures was modulation of the multixenobiotic-resistance protein activity (a decrease in the digestive gland and increase in the gills). The origin of population strongly affected the cellular stress responses of mussels. DPP-mussels showed depletion of caspase-3 in the digestive gland and up-regulation of HSP70, HSP72 and HSP60 levels in the gill during most exposures, whereas in the BPP-mussels caspase-3 was up-regulated and HSPs either downregulated or maintained stable. BPP-mussels were less adapted to heating shown by a glutathione depletion at elevated temperature (25 °C). Comparison with the earlier studies on mussels from pristine habitats show that an integrative 'eco-exposome'-based approach is useful for the forecast of the biological responses to novel adverse effects on aquatic organisms., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Pharmaceutical and personal care products (PPCPs) are the environmental pollutants of growing concern. The aim of this study was to indicate the effects of typical PPCPs on the marsh frog Pelophylax ridibundus. We treated male frogs with waterborne ibuprofen (IBU, 250ng·L -1 ), triclosan (TCS, 500ng·L -1 ), or estrone (E1, 100ng·L -1 ) for 14days. Common vulnerability of the frogs was detected from dramatic decrease of Zn, total and metalated metallothionein (MT) concentrations, Zn/Cu ratio, the elevation of activity of glutathione-S-transferase, cathepsin D and DNA instability in the liver, the depletion of cholinesterase in the brain and cortisol in the blood plasma in all exposures. Nevertheless, lipofuscin concentration in the liver was always decreased. The groups were best distinguished by cytochrome P450 (CYP450) activity determined by ELISA. The exposure to IBU caused lesser damage, but elevated the levels of oxyradicals and glutathione (GSH and GSSG) and lysosomal membrane instability. Exposures to TCS and E1 provoked the endocrine disturbance (increased levels of vitellogenin and thyrotropin in blood plasma), decreased lactate dehydrogenase activity and increased level of pyruvate in the liver. TCS caused the increase of GSSG by 7.3 times and lactate levels. Only E1 lead to decrease of deiodinase activity in the liver, activation of CYP450 and caspase-3 and efflux of cathepsin D from lysosomes. Spectrophotometric and ELISA assays of MTs and CYP450 gave distinct results in E1-group. Broad disruption of the hormonal pathways caused by E1 could be of concern for the health status of frogs in their habitats., (Copyright © 2017 Elsevier Inc. All rights reserved.)

The molluscan exoskeleton (shell) plays multiple important roles including structural support, protection from predators and stressors, and physiological homeostasis. Shell formation is a tightly regulated biological process that allows molluscs to build their shells even in environments unfavorable for mineral precipitation. Outer mantle edge epithelial cells (OME) and hemocytes were implicated in this process; however, the exact functions of these cell types in biomineralization are not clear. Pacific oysters ( Crassostrea gigas ) were used to study differences in the expression profiles of selected biomineralization-related genes in hemocytes and mantle cells, and the functional characteristics of hemocytes such as adhesion, motility and phagocytosis. The specialized role of OME in shell formation was supported by high expression levels of the extracellular matrix (ECM) related and cell-cell interaction genes. Density gradient separation of hemocytes revealed distinct phenotypes based on the cell morphology, gene expression patterns, motility and adhesion characteristics. These hemocyte fractions can be categorized into two functional groups, i.e. biomineralization and immune response cells. Gene expression profiles of the putative biomineralizing hemocytes indicate that in addition to their proposed role in mineral transport, hemocytes also contribute to the formation of the ECM, thus challenging the current paradigm of the mantle as the sole source of the ECM for shell formation. Our findings corroborate the specialized roles of hemocytes and the OME in biomineralization and emphasize complexity of the biological controls over shell formation in bivalves., Competing Interests: Competing interestsThe authors declare no competing or financial interests., (© 2017. Published by The Company of Biologists Ltd.)

Freshwater organisms including amphibians experience increasing exposures to emerging pollutants such as nanoparticles and pharmaceuticals, which can affect their fitness and performance. We studied the effects of two common pollutants extensively used in industry, pharmaceutical and personal care products, nano-zinc oxide (nZnO) and a Ca-channel blocker nifedipine (Nfd), on endocrine status and cellular stress markers of the marsh frog Pelophylax ridibundus. Males were exposed for 14days to nZnO (3.1μM), Zn 2+ (3.1μM, as a positive control for nZnO exposures), Nfd (10μM), and combination of nZnO and Nfd (nZnO+Nfd). Exposure to nZnO and Zn 2+ led to an increase in Zn burdens, elevated concentrations of the metal-bound metallothioneins (MT-Me) in the liver and increased vitellogenin in the serum, whereas exposures to Nfd and nZnO+Nfd resulted in the metal release from MTs and a significant increase in the ratio of total to metal-bound MTs. This likely reflects oxidative stress caused by Nfd exposures as manifested in the elevated levels of oxyradical production, upregulation of superoxide dismutase activity (SOD) and increase in the total and oxidized glutathione concentrations in Nfd-exposed frogs. Zn-containing exposures upregulated activity of deiodinase (in nZnO and nZnO+Nfd exposures) and serum thyrotropin level (in the case of Zn 2+ ). All exposures caused an increase in DNA fragmentation, lipofuscin accumulation as well as upregulation of caspase-3 and CYP450 levels reflecting cytotoxicity of the studied compounds in the liver. Across all experimental treatments, nZnO exposures in the absence of Nfd had the least impact on the cellular stress traits or redox status in frogs. This indicates that at the low environmentally relevant levels of pollution, pharmaceuticals such as Nfd and free metals (such as Zn 2+ ) may represent a stronger threat to the health of the frogs than nZnO particles., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Global climate change (GCC) can negatively affect freshwater ecosystems. However, the degree to which freshwater populations can acclimate to long-term warming and the underlying molecular mechanisms are not yet fully understood. We used the cooling water discharge (CWD) area of a power plant as a model for long-term warming. Survival and molecular stress responses (expression of molecular chaperones, antioxidants, bioenergetic and protein synthesis biomarkers) to experimental warming (20-41 °C, +1.5 °C per day) were assessed in invasive clams Corbicula fluminea from two pristine populations and a CWD population. CWD clams had considerably higher (by ~8-12 °C) lethal temperature thresholds than clams from the pristine areas. High thermal tolerance of CWD clams was associated with overexpression of heat shock proteins HSP70, HSP90 and HSP60 and activation of protein synthesis at 38 °C. Heat shock response was prioritized over the oxidative stress response resulting in accumulation of oxidative lesions and ubiquitinated proteins during heat stress in CWD clams. Future studies should determine whether the increase in thermal tolerance in CWD clams are due to genetic adaptation and/or phenotypic plasticity. Overall, our findings indicate that C. fluminea has potential to survive and increase its invasive range during warming such as expected during GCC.

Estuarine organisms including mollusks are exposed to periodic oxygen deficiency (hypoxia) that leads to a decrease in intracellular pH and accumulation of bicarbonate (HCO3(-)). These changes can affect cellular bioenergetics; however, their effects on mitochondria of estuarine mollusks are not well understood. We determined the interactive effects of bicarbonate (0-10mM) and pH (7.2 and 6.5) on mitochondrial oxygen consumption (ṀO2), membrane potential (Δψ) and production of reactive oxygen species (ROS) in two common estuarine bivalves - hard clams Mercenaria mercenaria, and bay scallops Argopecten irradians. In both species, elevated HCO3(-) levels suppressed ADP-stimulated (state 3) ṀO2 but had little effect on the resting (state 4) respiration. These effects were not mediated by the soluble adenylyl cyclase or cyclic AMP. Effects of the low pH (6.5) on mitochondrial traits were species-specific and depended on the substrate oxidized by the mitochondria. Mild acidosis (pH6.5) had minimal effects on ṀO2 and Δψ of the bivalve mitochondria oxidizing pyruvate but led to increased rates of ROS production in clams (ROS production could not be measured in scallops). In succinate-respiring mitochondria of clams, mild acidosis suppressed ṀO2 and increased mitochondrial coupling, while in scallop mitochondria the effects of low pH were opposite. Suppression of mitochondrial oxidative phosphorylation by bicarbonate and/or acidosis may contribute to the metabolic rate depression during shell closure or environmental hypoxia/hypercapnia. These findings have implications for understanding the physiological mechanisms involved in regulation of mitochondrial bioenergetics during hypoxia exposure in estuarine bivalves., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Metal-containing materials are extensively used in industry, personal care products and medicine, and their release in the environment causes concern for the potential impacts on aquatic organisms. We assessed endocrine disrupting potential of N-vinyl-2-pyrrolidone-based nanoparticles (Me-PSs) containing cobalt (Co(2+)) or zinc (Zn(2+)), using the marsh frog Pelophylax ridibundus as a model. Adult males were exposed for 14 days to waterborne Co(2+) (50μg/L), Zn(2+) (100μg/L) or corresponding concentrations of Co-PS, Zn-PS, or parental polymeric compound (PS). The indices of thyroid activity, vitellogenesis, cytochrome P450-dependent monooxygenases activity (EROD) and cytotoxicity markers were evaluated. Exposure to Co(2+) led to the elevation of serum thyrotropin (TSH) and hepatic deiodinase activities accompanied by the up-regulation of EROD activity. In contrast, the action of the polymer-containing substances (Co-PS, Zn-PS and PS) as well as free Zn(2+) caused a prominent decrease of EROD activity and a decrease in serum cortisol and TSH concentrations. Exposures to Zn(2+), Zn-PS and PS upregulated vitellogenesis in males. All exposures except Co(2+) caused neurotoxicity as indicated by the depletion of cholinesterase. These results demonstrate toxicity of Co- and Zn-containing Me-PSs and their parental compounds (Zn(2+) and PS) in frogs and indicate distinct mechanisms of Co(2+) action. Broad disruption of the hormonal pathways and reduced capacity for organic xenobiotic detoxification may have deleterious impacts on amphibian populations from habitats exposed to metallorganic pollution., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Despite numerous studies suggesting a dramatic decline of amphibians, the biochemical mechanisms of adaptation in these animals to polluted environment are poorly studied. The aim of this study was to elucidate the ability to release cobalt (Co) and zinc (Zn) from their nanoscale complexes (NCs) derived from the polymeric substance of N-vinylpyrrolidone (PS) in the liver of amphibian (Rana ridibunda). Frog males were subjected to 14days exposure to waterborne Co(2+) (50μg/L), Zn(2+) (100μg/L), as well as corresponding concentrations of Co-NC, Zn-NC or PS. Main attention was paid to MT's interrelations with indices of stress and toxicity. Only Co(2+) and Zn(2+) caused elevation of the correspondent metal in MTs. Co(2+) caused down-regulation of cathepsin D activity, while Zn(2+), Zn-NC and the PS up-regulated this activity. Zn(2+) provoked 1.6 times increase of metal-bounded form of the MT (MT-Me), while all other exposures caused the elevation of the ratio of MT total protein concentration (MT-SH) and concentrations of the MT-Me and/or immunoreactive (MTi) form (up to ~10 times) accompanied by a decrease in the levels of oxyradicals. The increased DNA fragmentation and down-regulation of caspase-3 activity in relation to the redox state of glutathione and/or lactate/pyruvate were shown at all exposures. These data indicate the vulnerability of the redox state of cellular thiols and inability to release Co and Zn from NCs in frog's liver., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Nanoparticle toxicity is a growing concern in freshwater habitats. However, understanding of the nanoparticle effects on aquatic organisms is impeded by the lack of the studies of the nanoparticles effects in the environmentally relevant context of multiple stress exposures. Zinc oxide nanoparticles (n-ZnO) are widely used metal-based nanoparticles in electronics and personal care products that accumulate in aquatic environments from multiple non-point sources. In this study, we evaluated the effects of n-ZnO in a model organism, a mussel Unio tumidus, and the potential modulation of these effects by common co-occurring environmental stressors. Male U. tumidus were exposed for 14 days to n-ZnO (3.1 μM), Zn(2+) (3.1 μM), Ca-channel blocker nifedipine (Nfd 10 μM), combinations of n-ZnO and Nfd or n-ZnO and thiocarbamate fungicide Tattoo (Ta, 91 μg L(-1)) at 18 °C, and n-ZnO at 25 °C (n-ZnO+t°). Total and metallothionein-bound Zn levels as well as levels of metallothioneins (MT), cellular stress responses and cytotoxicity biomarkers were assessed in the mussels. The key biomarkers that showed differential responses to different single and combined stressors in this study were activities of caspase-3 and lysosomal cathepsin D, as well as protein carbonyl content. At 18 °C, exposures to n-ZnO, organic pollutants and their combinations led to a prominent up-regulation of MT levels (by ∼30%) and oxidative stress response including up-regulation of superoxide dismutase activity, an increase in oxyradical production, and a 2-3-fold decrease in the levels of protein carbonyls in all exposures except nZnO+Ta. Expos ure to n-ZnO in the absence of other stressors also led to a strong (∼7-fold) elevation of cathepsin D activity. Cellular responses to Zn(2+) and n-ZnO were different indicating that n-ZnO was not due exclusively to Zn release. Ca-channel blocker Nfd affected intracellular Zn distribution (reflected in the prominent elevation of Zn-MT levels) and caused reductive stress indicated by elevated levels of reduced glutathione levels and an increase in lactate/pyruvate ratio (reflecting higher NADH/NAD ratio). Elevated temperature (25 °C) abolished most of the typical responses to n-ZnO and induced oxidative injury, DNA fragmentation and caspase-3 mediated apoptosis in n-ZnO-exposed mussels. DNA fragmentation was also induced by exposure to organic toxins (alone and in combination with n-ZnO) but not by n-ZnO alone. These data indicate that n-ZnO toxicity to freshwater organisms is modulated by organic pollutants and enhanced by elevated temperatures., (Copyright © 2015 Elsevier B.V. All rights reserved.)

The environmental safety of pharmaceutical and personal care products (PPCPs) requires a crucial examination. The aim of this study was to evaluate the responses of biomarkers of stress and toxicity in freshwater mussels to the effect of commonly found PPCPs in wastewater. We treated male mussels Unio tumidus, from an undisturbed site with ibuprofen (IBU, 250 ng L(-1)), triclosan (TCS, 500 ng L(-1)), or estrone (E1, 100 ng L(-1)) for 14 days. Untreated mussels from this site (C) and mussels inhabiting a polluted area (P) were also examined after a similar time of being kept in the laboratory. The consequences of chronic exposure of the mussels in the P-group were reflected in elevated concentrations of oxyradicals (1.4 times), oxidized glutathione (4.3 times), lipofuscin (2.2 times), and DNA-strand breaks in the digestive gland (DG) in comparison to the C-group, higher levels of caspase-3 activity in the DG, and vitellogenin-like proteins in gonads among all studied groups. Exposed mussels demonstrated some common responses with mussels in the P-group: elevated levels of lactate/pyruvate ratio, lipofuscin (IBU and E1), DNA fragmentation (TCS and E1), and caspase-3 activity (TCS and E1). Exposed to PPCPs mussels also showed elevation of ethoxyresorufin-O-deethylase and/or glutathione-S-transferase activity in the DG and a decrease in lysosomal stability in hemocytes (TCS and E1). The TCS group was distinguished by having the highest level of DNA-fragmentation and the lowest concentrations of total glutathione, oxyradicals, lipofuscin, pyruvate, and lactate, reflecting total metabolic depression. These results show that selected PPCPs at low concentrations alter a variety of physiological processes in this animal model system., (Copyright © 2014 Elsevier Inc. All rights reserved.)

The main goal of this study was to evaluate the ability of fish Carassius auratus tissues to release cobalt (Co) and zinc (Zn) cations present in the applied Co- and Zn-containing nanoscale composites (NCs). Male fish was subjected to 14day long action of Co- and Zn-NCs, as well as of Co(2+) and Zn(2+) or polymeric substance (PS) used for the NC preparation and derived from the vinylpyrrolidone. 50μg∙L(-1) of Co and 100μg∙L(-1) of Zn were applied either as a salt or a nanocomposite. Both Co and Co-NC increased (3.1 and 2.3 times, respectively) concentration of total Co, metallothionein-related Co (3.7 and 6.6 times, respectively) and thiols (by 71 and 95%, respectively), and caspase-3 activity (2.2 and 3.7 times, respectively) in the fish liver. At the same time, Co and Co-NC decreased glutathione level (1.8 and 1.9 times, respectively) and activated vitellogenesis (5.1 and 9.9 times, respectively) in the fish liver. Both Zn and Zn-NC increased markedly concentrations of metallothionein-related Zn (2.4 and 2.9 times, respectively) and Cu (2.8 and 3.2 times, respectively), and decreased metallothionein-related thiol (2.5 and 4.2 times, respectively), oxyradical (by 30.4 and 44.2%, respectively), and caspase-3 (3.0 and 5.3 times, respectively) levels in the fish liver. These peculiarities are common for metal and metal-NC and witness a release of metal from NS in fish organism. The differences in the levels of DNA strand breaks, biotransformation enzymes and total Zn levels in the liver were dependent on the kind of exposure., (Copyright © 2013 Elsevier Inc. All rights reserved.)

The aim of the present study was the investigation of the effect of in situ exposure history on the responses of freshwater mussels to thiocarbamate fungicide. Male bivalve mollusks Anodonta anatina (Unionidae) from polluted (A) and unpolluted (F) sites were subjected to 14 days of exposure to fungicide Tattoo (mixture of propamocarb and mancozeb, 91 μg L(-1)). When unexposed mussels were compared, chronic effect of toxic environment in site A was confirmed by oxidative stress indices (high levels of superoxide dismutase and catalase activities, lipid peroxidation, protein carbonyls and oxyradical production, low level of total glutathione (GSH)), genotoxicity (high levels of DNA-strand breaks and caspase-3 activity in digestive gland), and cytotoxicity (low lysosomal membrane stability in hemocytes), elevated vitellogenin-like proteins (Vtg-LP) concentration in gonads, high levels of Cu, Zn, Cd, metallothionein (MT)-bound metals (MT-Me) and MT-related thiol (MT-SH), and low ethoxyresorufin-O-deethylase (EROD) activity in digestive gland. The major differences in the responses of the two exposed groups were related to antioxidant defense and MT: in the group A, prominent oxidative stress response with the participation of MT-SH and GSH in the gills, EROD activation, but decrease of MT-Me level was shown, whereas in group F exposure provoked the elevation of MT-Me, caspase-3 and Vtg-LP values. Carbamate did not cause cholinesterase depletion and cytotoxicity. However, genotoxic and pro-oxidant effects (increased levels of hemocytes with micronuclei and nuclear abnormalities, DNA-strand breaks and oxyradical in digestive gland), were common responses for both the exposed groups.

The goal of the study was to assess the adequacy of molecular responses in mollusks in relation to their in situ exposure history. Freshwater male bivalve mollusks Anadonta anatina (Unionidae) from polluted (A) and unpolluted (F) sites were subjected to 14 days of exposure to copper (Cu(2+), 10 μg L(-1)), zinc (Zn(2+), 130 μg L(-1)) or cadmium (Cd(2+), 15 μg L(-1)). The comparison of two control groups showed that the specimens from site A had higher levels of Cu, Zn and Cd and metallothionein (measured both through metal (MT-Me), and protein (MT-SH) levels) in the tissues. Cytotoxicity (low lysosomal membrane stability), low glutathione level, high antioxidant and apoptotic enzymes activities, lipid and protein oxidative injury, depletion of ethoxyresorufin-O-deethylase (EROD) in digestive gland, high vitellogenin-like protein (Vtg-LP) concentration in gonads confirmed the effect of toxic environment on this group. Exposures provoked increased number of hemocytes with micronuclei (by 100-500%) and nuclear abnormalities (by 50-400%) (genotoxicity), elevation of caspase-3 (in 1.5-10 times) and/or Vtg-LP (by 70-310%) levels in all groups. However, the responses were strongly dependent on the origin of mussels. Exposed mussels from site F demonstrated typical for the effect of toxic metals elevation of MT-SH (by 100-380%) and MT-Me (up to seven times) levels and accumulation of metals (with a few exceptions) in the tissues. Conversely, in the mussels inhabiting site A, exposures caused the decrease of metal (by 37% for Cu, by 62% for Zn, by 50% for Cd), MT-SH (by 68% in ZnA group) and MT-Me (by 50-68%) levels. That was accompanied with increase of cytotoxicity and EROD activity (by 144-240%). High level of protein carbonyls was the distinguished feature of all groups from site A. Hence, despite high efficiency of metal detoxification and oxidative stress responses in the mussels, in the specimens from spontaneously polluted site they were impaired., (Copyright © 2012 Elsevier Inc. All rights reserved.)

The aim of this study was to appreciate the consequences of spontaneous human activity for freshwater mollusks in the generally ecologically sustainable area in Western Ukraine. For this, bivalve mollusk, Anodonta cygnea, at three sites, with mixed agricultural and municipal activities (A), close to a municipal water inlet (F) and the cooling pond of a nuclear power plant (N), were studied in spring, summer, and autumn. The set of parameters included the characteristics of oxidative stress (activity of catalase (CAT), levels of protein carbonyls (PC)), levels of reduced and oxidized glutathione (GSH, GSSG, respectively), activities of lactate dehydrogenase (LD), cholinesterase (ChE), ethoxyresorufin-O-deethylase (EROD), glutathione S-transferase (GST) in the digestive gland, and concentrations of vitellogenin-like proteins (Vtg-LP) in gonads and also morphological indices. Although the discriminant functional analysis confirmed the general seasonal regularities for studied groups, it allowed to discriminate between sites (P < 0.05). At site A, oxidative stress; high levels of LD, EROD, and GST; and low levels of ChE and condition factor were reflected. This demonstrated the sensitivity of mussels to constant effect of mixed pollution. At site N, oxidative injury was shown that might be explained by the constantly high temperature. At site F, abrupt elevations of Vtg-LP and EROD levels in autumn were probably related to an emergency situation on the nearby dump. So, both chronic and temporal environmental effects were reflected by a set of markers in mollusk. The classification and regression tree (CART) algorithm selected GSH and PC in the digestive gland and Vtg-LP as partitioning criteria for the characterization of mussel health status. © 2010 Wiley Periodicals, Inc. Environ Toxicol, 2012., (Copyright © 2010 Wiley Periodicals, Inc.)

Cobalt (Co(2+)) is present in many nanoscaled materials created for various applications. The key goal of our study was to develop sensitive approaches for assessing the bio-risks associated with using novel Co(2+)-containing nanoscaled polymeric complex (Co-NC). Freshwater bivalve mollusk Anodonta cygnea (Unionidae) was subjected to 14 d action of the developed Co-NC, as well as of Co(2+) applied in the corresponding concentration (50 μg L(-1)) or polymeric substance (PS). All experimental groups under study have demonstrated signs of toxic targeting, notably changes in DNA characteristics, oxidative stress (with particularities in each exposed group) and activation of anaerobiosis (Co(2+) and Co-NC). However, the group exposed to Co-NC showed some advantages that can be related to the activation of metallothionein (MT) function (increase in the level of MT-related SH-groups (MT-SH)): low level of oxyradical formation, no increase in protein carbonylation and vitellogenin-like proteins concentration unlike in Co(2+) and PS exposed groups. On the other hand, Co(2+) increased metal (Co, Cu, Zn and Cd) binding to MT (MT-Me) without changes in MT-SH level jointly with activation of oxyradical formation and apoptosis and decreasing of lysosomal membrane stability. PS per se initiated unbalanced changes in activities of the biotransformation enzymes ethoxyresorufin-O-deethylase and glutathione-S-transferase. Thus, Co(2+) complexing with the developed PS prevented bio-toxic effects of free Co(2+) ions and PS per se, at least in the studied hydrobiont. The MT-SH was the main distinguishing index of Co-NC group selected by classification and regression tree analysis., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

The aim of this study was to evaluate population-related peculiarities of the adaptive responses of Carassius auratus gibelio. In order to do this, male specimens from polluted (B) and clean (Z) sites were exposed to commercial pesticides thiocarbamate Tatoo (9.1 μg·L(-1)and 91 μg·L(-1)) or tetrazine Apollo (2 μg·L(-1) and 10 μg·L(-1)) during fourteen days. The control fish from site B was distinguished by weakness of antioxidant defence (measured from superoxide dismutase and catalase activities, redox index of glutathione (GSH), superoxide anion (O(2)) and lipid peroxidation levels), imbalance of the concentrations of protein metallothionein (MT-SH) and MT-related metals (MT-Me) and neurotoxicity. Differences in glutathione-S-transferase activity in the liver and vitellogenin-like proteins in the serum were also showed between B and Z control groups. Common effects of pesticides were related to a decrease in GSH, an increase in O(2) production, ethoxyresorufin O-deethylase activity and hepatosomatic index. Apollo provoked particular elevation of MT-SH/MT-Me ratio. Population-related difference in the response was the activation of antioxidant defence in fish from site B and its inhibition in fish from site Z. The genotoxic effect of exposures was more expressed in fish from site B. Principal component analysis combine all exposed groups from site Z and control group from site B in one set, and separated each exposed group from site B. The main distinguishing index of each population selected by classification and regression tree analysis was MT-SH., (Copyright © 2011 Elsevier Inc. All rights reserved.)

The aim of this study was to compare the effect of pro-oxidants copper (Cu(2+), 0.005 and 0.050mg L(-1)) or manganese (Mn(2+), 0.17 and 1.7mg L(-1)) on Carassius auratus gibelio from polluted (B) and unpolluted (Z) sites after exposure for fourteen days. Fish from site B showed high levels of lipid peroxidation (TBARS concentration), lower levels of metallothionein (MT)-related metal, total glutathione (GSH), its redox index, superoxide dismutase (Cu,Zn- and Mn-SOD), glutathione-S-transferase (GST) and cholinesterase (ChE) activities and also higher MT-related thiol concentration in the liver and gills. A common effect of exposure was related to genotoxicity, a decrease in GSH and an increase in microsomal ethoxyresorufin O-deethylase activity in the liver. However, the systems of oxidative stress and biotransformation were more efficient in fish from the polluted site, while the responsivity of MTs in this fish was impaired. Principle Component Analysis separated the subgroups from the unpolluted site and fish loaded by lesser concentrations of metals on the one side, and fish from the polluted site jointly with fish exposed to higher concentrations of metals on the other side. The main distinguishing indices of sites and exposures selected by classification and regression tree (CART) analysis were MT characteristics and genotoxicity., (Copyright © 2011 Elsevier Inc. All rights reserved.)