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1.
PLoS One ; 15(8): e0234166, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32797098

RESUMO

Response to simultaneous stressors is an important facet of plant ecology and land management. In a greenhouse trial, we studied how eight plant species responded to single and combined effects of three soil concentrations of the phytotoxic munitions constituent RDX and two levels of water-resourcing. In an outdoor trial, we studied the effects of high RDX soil concentration and two levels of water-resourcing in three plant species. Multiple endpoints related to RDX fate, plant health, and plant survival were evaluated in both trials. Starting RDX concentration was the most frequent factor influencing all endpoints. Water-resourcing also had significant impacts, but in fewer cases. For most endpoints, significant interaction effects between RDX concentration and water-resourcing were observed for some species and treatments. Main and interaction effects were typically variable (significant in one treatment, but not in another; associated with increasing endpoint values for one treatment and/or with decreasing endpoint values in another). This complexity has implications for understanding how RDX and water-availability combine to impact plants, as well as for applications like phytoremediation. As an additional product of these greenhouse and outdoor trials, three plants native or naturalized within the southeastern United States were identified as promising species for further study as in situ phytoremediation resources. Plumbago auriculata exhibited relatively strong and markedly consistent among-treatment mean proportional reductions in soil RDX concentrations (112% and 2.5% of the means of corresponding values observed within other species). Likewise, across all treatments, Salvia coccinea exhibited distinctively low variance in mean leaf chlorophyll content index levels (6.5% of the means of corresponding values observed within other species). Both species also exhibited mean wilting and chlorosis levels that were 66% and 35%, and 67% and 84%, of corresponding values observed in all other plants, respectively. Ruellia caroliniensis exhibited at least 43% higher mean survival across all treatments than any other test species in outdoor trials, despite exhibiting similar RDX uptake and bioconcentration levels.


Assuntos
Substâncias Explosivas/toxicidade , Plantas/efeitos dos fármacos , Poluentes do Solo/toxicidade , Triazinas/toxicidade , Acanthaceae/efeitos dos fármacos , Acanthaceae/crescimento & desenvolvimento , Acanthaceae/fisiologia , Biodegradação Ambiental , Substâncias Explosivas/administração & dosagem , Substâncias Explosivas/farmacocinética , Instalações Militares , Desenvolvimento Vegetal/efeitos dos fármacos , Fenômenos Fisiológicos Vegetais/efeitos dos fármacos , Plumbaginaceae/efeitos dos fármacos , Plumbaginaceae/crescimento & desenvolvimento , Plumbaginaceae/fisiologia , Salvia/efeitos dos fármacos , Salvia/crescimento & desenvolvimento , Salvia/fisiologia , Poluentes do Solo/administração & dosagem , Poluentes do Solo/farmacocinética , Sudeste dos Estados Unidos , Estresse Fisiológico/efeitos dos fármacos , Triazinas/administração & dosagem , Poluentes Químicos da Água/administração & dosagem , Poluentes Químicos da Água/farmacocinética , Poluentes Químicos da Água/toxicidade , Recursos Hídricos
2.
J Toxicol Environ Health A ; 83(3): 113-125, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-32116137

RESUMO

Simvastatin (SIM), a hypocholesterolaemic drug belonging to the statins group, is a widely prescribed pharmaceutical for prevention of cardiovascular diseases. Several studies showed that lipophilic statins, as SIM, cross the blood-brain barrier and interfere with the energy metabolism of the central nervous system in humans and mammalian models. In fish and other aquatic organisms, the effects of SIM on the brain energy metabolism are unknown, particularly following exposure to low environmentally relevant concentrations. Therefore, the present study aimed at investigating the influence of SIM on gene signaling pathways involved in brain energy metabolism of adult zebrafish (Danio rerio) following chronic exposure (90 days) to environmentally relevant SIM concentrations ranging from 8 ng/L to 1000 ng/L. Real-time PCR was used to determine the transcript levels of several genes involved in different pathways of the brain energy metabolism (glut1b, gapdh, acadm, accα, fasn, idh3a, cox4i1, and cox5aa). The findings here reported integrated well with ecological and biochemical responses obtained in a parallel study. Data demonstrated that SIM modulates transcription of key genes involved in the mitochondrial electron transport chain, in glucose transport and metabolism, in fatty acid synthesis and ß-oxidation. Further, SIM exposure led to a sex-dependent transcription profile for some of the studied genes. Overall, the present study demonstrated, for the first time, that SIM modulates gene regulation of key pathways involved in the energy metabolism in fish brain at environmentally relevant concentrations.


Assuntos
Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Sinvastatina/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Anticolesterolemiantes/administração & dosagem , Anticolesterolemiantes/toxicidade , Bioensaio , Esquema de Medicação , Feminino , Humanos , Masculino , Sinvastatina/administração & dosagem , Poluentes Químicos da Água/administração & dosagem , Peixe-Zebra
3.
Chemosphere ; 240: 124862, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31550591

RESUMO

The photodegradation of benzisothiazolinone was studied in water under UV-Vis irradiation and led to fourteen photoproducts. Chemical structures of these compounds were elucidated using GC-MS, LCMS/MS, and FT-ICR-MS experiments. Based on the chemical structures determined and their appearance order, a photo induced-degradation mechanism of benzisothiazolinone has been proposed, which combines isomerization, oxidation, hydroxylation, hydrolysis, and elimination processes. In silico tests on mutagenicity, Fathead minnow LC50 and oral rat LD50 were carried out to estimate the toxicity of the photoproducts. Compared with experimental data, the calculated oral rat LD50 values were found to be the most relevant and thus used for toxicity estimation. The photoproducts including a phenolic or a sulfino group or both functions were found potentially more toxic than benzisothiazolinone.


Assuntos
Tiazóis/química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/toxicidade , Administração Oral , Animais , Cromatografia Líquida , Simulação por Computador , Cyprinidae , Cromatografia Gasosa-Espectrometria de Massas , Cinética , Espectrometria de Massas , Fotólise , Ratos , Relação Estrutura-Atividade , Tiazóis/toxicidade , Testes de Toxicidade , Raios Ultravioleta , Poluentes Químicos da Água/administração & dosagem , Poluentes Químicos da Água/análise
4.
Drug Chem Toxicol ; 43(3): 287-297, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-30554537

RESUMO

Mercury (Hg) is among the most deleterious contaminant in the aquatic environment and presents a serious risk to humans and ecosystems. This study evaluated the effects of Hg on oxidative stress biomarkers, DNA integrity and histological structure of the respiratory tree of Holothuria forskali exposed to different concentrations of mercury chloride HgCl2 (0.04, 0.08 and 0.16 mg L-1) for 96 h. Exposure of H. forskali to Hg led to oxidative stress with an increase in Malondialdehyde (MDA), hydrogen peroxide (H2O2), advanced oxidation protein product (AOPP) and protein carbonyls (PCO) levels in the treated groups. Alteration of the antioxidant system was also confirmed by the significant increase in glutathione (GSH), nonprotein thiol (NPSH) and vitamin C contents. Moreover, the enzymatic activity of superoxide dismutase (SOD), Glutathione peroxidase (GPX) and Catalase (CAT) increased significantly. Our research revealed that total Metallothionein (MTs) content enhanced in a dose-dependent manner. Interestingly, the exposure to this metal provoked a decrease in Acetylcholinesterase (AChE) activity. Hg genotoxicity was further evidenced by a random DNA degradation that was observed in the treated groups. The histopathological findings confirmed the biochemical results. Overall, our results indicated that mercury-induced genotoxicity, oxidative damage and histopathological injuries in the respiratory tree of H. forskali.


Assuntos
Cloreto de Mercúrio/toxicidade , Metalotioneína/genética , Mutagênicos/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Antioxidantes/metabolismo , Biomarcadores/metabolismo , Relação Dose-Resposta a Droga , Holothuria/efeitos dos fármacos , Cloreto de Mercúrio/administração & dosagem , Testes de Mutagenicidade , Mutagênicos/administração & dosagem , Oxirredução/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Sistema Respiratório/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos , Poluentes Químicos da Água/administração & dosagem
5.
Arch Toxicol ; 93(10): 2811-2822, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31493028

RESUMO

Mice have been frequently used to study the adverse effects of inorganic arsenic (iAs) exposure in laboratory settings. Like humans, mice metabolize iAs to monomethyl-As (MAs) and dimethyl-As (DMAs) metabolites. However, mice metabolize iAs more efficiently than humans, which may explain why some of the effects of iAs reported in humans have been difficult to reproduce in mice. In the present study, we searched for mouse strains in which iAs metabolism resembles that in humans. We examined iAs metabolism in male mice from 12 genetically diverse Collaborative Cross (CC) strains that were exposed to arsenite in drinking water (0.1 or 50 ppm) for 2 weeks. Concentrations of iAs and its metabolites were measured in urine and livers. Significant differences in total As concentration and in proportions of total As represented by iAs, MAs, and DMAs were observed between the strains. These differences were more pronounced in livers, particularly in mice exposed to 50 ppm iAs. In livers, large variations among the strains were found in percentage of iAs (15-48%), MAs (11-29%), and DMAs (29-66%). In contrast, DMAs represented 96-99% of total As in urine in all strains regardless of exposure. Notably, the percentages of As species in urine did not correlate with total As concentration in liver, suggesting that the urinary profiles were not representative of the internal exposure. In livers of mice exposed to 50 ppm, but not to 0.1 ppm iAs, As3mt expression correlated with percent of iAs and DMAs. No correlations were found between As3mt expression and the proportions of As species in urine regardless of exposure level. Although we did not find yet a CC strain in which proportions of As species in urine would match those reported in humans (typically 10-30% iAs, 10-20% MAs, 60-70% DMAs), CC strains characterized by low %DMAs in livers after exposure to 50 ppm iAs (suggesting inefficient iAs methylation) could be better models for studies aiming to reproduce effects of iAs described in humans.


Assuntos
Arsênico/farmacocinética , Poluentes Químicos da Água/farmacocinética , Animais , Arsênico/administração & dosagem , Relação Dose-Resposta a Droga , Variação Genética , Masculino , Camundongos , Especificidade da Espécie , Distribuição Tecidual , Poluentes Químicos da Água/administração & dosagem
6.
Mar Pollut Bull ; 149: 110556, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31546108

RESUMO

Copper (Cu) in an essential trace metal but it can also contaminate coastal waters at high concentrations mainly from agricultural run-off and mining activities which are detrimental to marine organisms including seagrasses. The molecular mechanisms driving Cu toxicity in seagrasses are not clearly understood yet. Here, we investigated the molecular responses of the Australian seagrass, Z. muelleri at the whole transcriptomic level after 7 days of exposure to 250 µg Cu L-1 and 500 µg Cu L-1. The leaf-specific whole transcriptome results showed a concentration-dependent disturbance in chloroplast function, regulatory stress responses and defense mechanisms. This study provided new insights into the responses of seagrasses to trace metal stress and reports possible candidate genes which can be considered as biomarkers to improve conservation and management of seagrass meadows.


Assuntos
Cobre/toxicidade , Poluentes Químicos da Água/toxicidade , Zosteraceae/efeitos dos fármacos , Zosteraceae/genética , Organismos Aquáticos , Cobre/administração & dosagem , Relação Dose-Resposta a Droga , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/genética , Poluentes Químicos da Água/administração & dosagem
7.
Environ Sci Pollut Res Int ; 26(30): 30857-30865, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31446602

RESUMO

Recently, the residues of some common and widely used herbicides (acetochlor, bispyribac-sodium, bentazon, bensulfuron-methyl, halosulfuron-methyl, and quinclorac) were detected in the surface water, soil, sediments, and fish tissues as the agricultural drainage problems. In this study, juveniles of Nile tilapia Oreochromis niloticus were exposed to sub-lethal concentrations of these herbicides as 2.625, 0.800, 36.00, 2.50, 1.275, and 11.250 mg/l for acetochlor, bispyribac-sodium, bentazon, bensulfuron-methyl, halosulfuron-methyl, and quinclorac respectively for 96 h. Some hemato-biochemical parameters were evaluated. In comparison with the control group, sub-lethal concentrations of all tested herbicides induced alterations in the shape of erythrocytes. Also, in all tested herbicides, hematological parameters of exposed fish exhibited a significant decrease in red blood cell count except bentazon. However, all tested herbicides showed an insignificant reduction in mean corpuscular hemoglobin concentration and total white blood cells except bensulfuron-methyl. For biochemical parameters, most tested herbicides induced a significant increase in levels of cholesterol, albumin, globulin, albumin/globulin ratio, activity of alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total plasma protein (only with acetochlor), urea, and creatinine (except bentazon and halosulfuron-methyl that exhibited non-significant decrease in creatinine level) compared with the control. In conclusion, the fish blood profiles can be used as good biomarkers for laboratory study to assess the toxicity of the tested rice herbicides at a sub-acute level especially acetochlor on O. niloticus. Graphical Abstract.


Assuntos
Ciclídeos/sangue , Biomarcadores Ambientais/efeitos dos fármacos , Herbicidas/toxicidade , Poluentes Químicos da Água/toxicidade , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , Creatinina/sangue , Ecotoxicologia , Eritrócitos/efeitos dos fármacos , Proteínas de Peixes/sangue , Herbicidas/administração & dosagem , Poluentes Químicos da Água/administração & dosagem
8.
Food Chem Toxicol ; 133: 110760, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31421213

RESUMO

Arsenic is a common toxic contaminant in food and drinking water. Metabolic activation of arsenic species produces reactive trivalent intermediates that can disrupt cellular regulatory systems by covalent binding to thiol groups. Arsenic exposures have been associated with human diseases including cancer, diabetes, lung and cardiovascular disorders and there is accumulating evidence that early life exposures are important in the etiology. Previous toxicokinetic studies of arsenite ingestion in neonatal CD-1 mice showed consistent evidence for metabolic and physiologic immaturity that led to elevated internal exposures to trivalent arsenic species in the youngest mice, relative to adults. The current study in rhesus monkeys showed that metabolism and binding of trivalent intermediates after arsenite ingestion were similar between adult monkeys and CD-1 mice. Unlike neonatal mice, monkeys from the age of 5-70 days showed similar metabolism and binding profiles, which were also similar to those in adults. The absence of evidence for metabolic immaturity in monkeys suggests that toxicological effects observed in mice from early postnatal exposures to arsenic could over-predict those possible in primates, based on significantly higher internal exposures.


Assuntos
Arsenitos/farmacocinética , Compostos de Sódio/farmacocinética , Poluentes Químicos da Água/farmacocinética , Administração Oral , Fatores Etários , Animais , Animais Recém-Nascidos/metabolismo , Arsenitos/administração & dosagem , Arsenitos/metabolismo , Eritrócitos/metabolismo , Feminino , Macaca mulatta/metabolismo , Masculino , Camundongos , Compostos de Sódio/administração & dosagem , Compostos de Sódio/metabolismo , Poluentes Químicos da Água/administração & dosagem , Poluentes Químicos da Água/metabolismo
9.
PLoS One ; 14(7): e0219161, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31339879

RESUMO

Ammonium pulse attributed to runoff of urban surface and agriculture following heavy rain is common in inland aquatic systems and can cause profoundly effects on the growth of macrophytes, especially when combined with low light. In this study, three patterns of NH4-N pulse (differing in magnitude and frequency) were applied to examine their effects on the growth of three submersed macrophytes, namely, Myriophyllum spicatum, Potamogeton maackianus, and Vallisneria natans, in terms of biomass, height, branch/ramet number, root length, leaf number, and total branch length under high and low light. Results showed that NH4-N pulse caused negative effects on the biomass of the submerged macrphytes even on the 13th day after releasing NH4-N pulse. The negative effects on M. spicatum were significantly greater than that on V. natans and P. maackianus. The effects of NH4-N pulse on specific species depended on the ammonium loading patterns. The negative effects of NH4-N pulse on P. maackianus were the strongest at high loading with low frequency, and on V. natans at moderate loading with moderate frequency. For M. spicatum, no significant differences were found among the three NH4-N pulse patterns. Low light availability did not significantly aggregate the negative effects of NH4-N pulse on the growth of the submersed macrophytes. Our study contributes to revealing the roles of NH4-N pulse on the growth of aquatic plants and its species specific effects on the dynamics of submerged macrophytes in lakes.


Assuntos
Compostos de Amônio/administração & dosagem , Hydrocharitaceae/efeitos dos fármacos , Hydrocharitaceae/crescimento & desenvolvimento , Lagos/análise , Potamogetonaceae/efeitos dos fármacos , Potamogetonaceae/crescimento & desenvolvimento , Saxifragales/efeitos dos fármacos , Saxifragales/crescimento & desenvolvimento , Compostos de Amônio/toxicidade , Organismos Aquáticos/efeitos dos fármacos , Organismos Aquáticos/crescimento & desenvolvimento , Biomassa , China , Ecossistema , Eutrofização/efeitos dos fármacos , Nitrogênio/administração & dosagem , Nitrogênio/toxicidade , Chuva/química , Água/análise , Poluentes Químicos da Água/administração & dosagem , Poluentes Químicos da Água/toxicidade
10.
Food Chem Toxicol ; 132: 110597, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31233874

RESUMO

Arsenic is prevalent in contaminated drinking water and affects more than 140 million people in 50 countries. While the wide-ranging effects of arsenic on neurological development and cancer draw the majority of concern, arsenic's effects on the gut mucosa-associated immune system are often overlooked. In this study, we show that 24 h after a single dose [low dose (50 µg/kg bw), medium dose (100 µg/kg bw) or high dose (200 µg/kg bw)] of arsenic by oral gavage, mice show significantly reduced gut mucosa-associated mRNA expression for the key genes involved in the signaling pathways central to immune responses, such as Nuclear factor κB (NFκB), Extracellular signal-regulated protein kinases 1 and 2 (ERK1/2), p38 and Myeloid differentiation protein 88-dependent (Myd88) pathways. Additionally, mRNA expression of apoptosis, inflammasomes and inflammatory response genes are significantly downregulated in the animals exposed to arsenic. Comparisons of time-dependent effects (24 h vs 48 h) from low dose arsenic exposed animals showed a significant shift in expression of Myd88 alone, suggesting that the down regulation was sustained for the key genes/signaling pathway. An extended eight-day exposure to arsenic showed a decreased state of immune preparedness, though not as diminished as seen in the single dose exposure.


Assuntos
Arsênico/efeitos adversos , Sistema Imunitário/efeitos dos fármacos , Intestinos/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , RNA Mensageiro/metabolismo , Poluentes Químicos da Água/efeitos adversos , Administração Oral , Animais , Arsênico/administração & dosagem , Regulação para Baixo , Feminino , Inflamassomos/genética , Intestinos/imunologia , Sistema de Sinalização das MAP Quinases/genética , Camundongos , Fator 88 de Diferenciação Mieloide/genética , NF-kappa B/genética , RNA Mensageiro/genética , Fatores de Tempo , Poluentes Químicos da Água/administração & dosagem
11.
Artigo em Inglês | MEDLINE | ID: mdl-31055069

RESUMO

Sea-Nine™ 211 is an emerging biocide that has an adverse impact on aquatic environments. In this study, the marine polychaete Perinereis aibuhitensis was exposed to Sea-Nine (0.1, 1, and 10 µg L-1), and acute toxicity and biochemical responses such as changes in the intracellular contents of malondialdehyde (MDA) and glutathione (GSH) and enzymatic activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferase (GST), and acetylcholinesterase (AChE) were evaluated over a period of 14 d. Determined median lethal doses, LC50 were 268 µg L-1, 142 µg L-1, and 55 µg L-1 at 24 h, 96 h, and 14 d, respectively. The MDA content increased significantly in a dose- and time-dependent manner, indicative of lipid peroxidation-related oxidative damage. Significantly higher intracellular GSH levels and antioxidant defense-related enzyme (CAT, SOD, GPx, GR, and GST) activities were observed after exposure to 10 µg L-1 Sea-Nine. In contrast, Sea-Nine treatment significantly reduced AChE activity at the highest concentration of Sea-Nine used (10 µg L-1). Taken together, these results indicate that sublethal concentrations of Sea-Nine are toxic to marine polychaetes through potential lipid peroxidation, induction of oxidative stress, and modulation of the cholinergic system. Our results can contribute to biomonitoring of aquatic environments and ecotoxicological research through the measurements of polychaete cellular defenses against waterborne biocides.


Assuntos
Desinfetantes/toxicidade , Poliquetos/efeitos dos fármacos , Tiazóis/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Antioxidantes/metabolismo , Relação Dose-Resposta a Droga , Esquema de Medicação , Glutationa/metabolismo , Malondialdeído/metabolismo , Tiazóis/administração & dosagem , Poluentes Químicos da Água/administração & dosagem
12.
Artigo em Inglês | MEDLINE | ID: mdl-31129174

RESUMO

The importance of trace elements in ecotoxicological investigations is a well-known issue when monitoring polluted areas such as commercial harbors. Copper represents one of the most common metal contaminants, often detected in these areas as it is widely employed in various fields and has many sources of inflow in the marine environment. Pachygrapsus marmoratus is a widespread intertidal crab species that has been extensively studied in ecology, ethology and population genetics. Ecotoxicological studies have also been performed, exclusively on the adult stage. In the present study we investigated the mortality and biochemical (oxidative stress and neurotoxicity) responses of P. marmoratus larvae exposure to environmental relevant concentration of copper. Results showed dose-dependent responses in terms of larval mortality, with a calculated LC50 value of 0.5 mg/L of Cu2+. The LC50 concentration was used as the starting point for subsequent biochemical response evaluation. Results also demonstrated dose-dependent activation of antioxidant systems assuming a compensatory antioxidant activity to prevent higher cellular damage when larvae were exposed to the highest concentrations of copper. Moreover, a significant enhancement of neurotransmitter activities was observed, assuming a possible direct interaction of copper with the enzymes or an increase of free copper ion aliquot into the cells.


Assuntos
Braquiúros/efeitos dos fármacos , Cobre/toxicidade , Animais , Biomarcadores/metabolismo , Braquiúros/metabolismo , Catalase/metabolismo , Colinesterases/metabolismo , Cobre/administração & dosagem , Relação Dose-Resposta a Droga , Feminino , Glutationa Peroxidase/metabolismo , Larva/efeitos dos fármacos , Mortalidade , Estresse Oxidativo/efeitos dos fármacos , Superóxido Dismutase/metabolismo , Testes de Toxicidade , Poluentes Químicos da Água/administração & dosagem , Poluentes Químicos da Água/toxicidade
13.
Chem Res Toxicol ; 32(6): 995-1001, 2019 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-30942079

RESUMO

Flutolanil is a broad-spectrum amide fungicide that is widely used to prevent fungal pathogens in agriculture. However, its usage may have a potential environmental impact on organisms. So far, few literatures have investigated the chronic toxicity of flutolanil at concentrations relevant to environmental conditions in the nontarget aquatic organisms. This study was aimed at evaluating whether the long-term exposure of flutolanil affects oxidative stress, immune response, and apoptosis in the liver of zebrafish ( Danio rerio). The results showed that the activity of catalase (CAT) was significantly decreased in the liver in all flutolanil-treated groups. Interestingly, the malondialdehyde (MDA) contents were remarkably increased following the flutolanil exposure. Deoxyribonucleic acid (DNA) damage was increased with a concentration-dependent manner. The transcription level of genes involved in apoptosis and the immune system were significantly altered following flutolanil chronic exposure in zebrafish liver. Furthermore, the caspase-3 enzyme activity was significantly increased. Taken together, this study demonstrated that the resulting effects on oxidative stress, immune toxicity, and apoptosis may be responsible for the pathological alterations in zebrafish liver after flutolanil exposure at concentrations relevant to environmental conditions, advancing the knowledge of pesticide environmental risk assessment.


Assuntos
Anilidas/toxicidade , Fígado/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Peixe-Zebra , Anilidas/administração & dosagem , Animais , Apoptose/efeitos dos fármacos , Relação Dose-Resposta a Droga , Fígado/metabolismo , Fígado/patologia , Estrutura Molecular , Estresse Oxidativo/efeitos dos fármacos , Poluentes Químicos da Água/administração & dosagem
14.
Toxicol Appl Pharmacol ; 372: 33-39, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30978399

RESUMO

Historical uranium (U) mining in the Southwestern United States resulted in significant environmental contamination throughout this region and presents a significant risk of chronic metal exposure and toxicity for communities living in close proximity to mine waste sites. Uranium exposure is associated with numerous deleterious health effects including immune dysfunction; however, its effects on the immune system have yet to be fully characterized. We recently published that drinking water exposure to U, in the form of uranyl acetate (UA), results in low overall tissue retention of U (<0.01%), with very little accumulation in immune organs (blood, bone marrow, spleen, and thymus) of male and female mice. In the present study we characterized the immunotoxicity of U, in the form of UA, following a 60-day drinking water exposure to 5 and 50 ppm in male and female C57BL/6J mice. The following immunotoxicity endpoints were evaluated: hematology, immune tissue weights and total cell recoveries, immunophenotying of the spleen and thymus, and immune cell function (lymphocyte mitogenesis and T-dependent antibody response). Uranium exposure had subtle impacts on the immune endpoints evaluated, likely due to low U accumulation at these sites. The only significant alterations were a slight decrease in the percentages of splenic natural killer T-cells and macrophages in exposed male mice. Despite minimal immunological effects, this study highlights the importance of investigating toxicological endpoints in both sexes and developing accurate animal models that model epidemiological exposures in the future.


Assuntos
Imunidade Humoral/efeitos dos fármacos , Imunidade Inata/efeitos dos fármacos , Compostos Organometálicos/toxicidade , Poluentes Químicos da Água/toxicidade , Administração Oral , Animais , Células Cultivadas , Feminino , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Masculino , Camundongos Endogâmicos C57BL , Células T Matadoras Naturais/efeitos dos fármacos , Células T Matadoras Naturais/imunologia , Compostos Organometálicos/administração & dosagem , Fatores Sexuais , Baço/efeitos dos fármacos , Baço/imunologia , Baço/metabolismo , Fatores de Tempo , Poluentes Químicos da Água/administração & dosagem
15.
Artigo em Inglês | MEDLINE | ID: mdl-30930206

RESUMO

During the past decade, the total population and overall reproductive performance of the oriental river prawn (Macrobrachium nipponense) in the Anzali international wetland and its basin rivers has been severely reduced. This seems to be caused by an increase in heavy metal pollution from industrial wastewaters. We investigated the effects of chronic levels of lead (Pb) and cadmium (Cd) on reproductive success, hemato-immunology, crustacean hyperglycemic hormone (cHH), Pb/Cd bioaccumulation and histopathology of hepatopancreas of oriental river prawn. The present study was separately carried out using four chronic treatments for Pb (0 (control), 0.024, 0.072 and 0.12 µM/l) and Cd (0 (control), 0.026, 0.053 and 0.08 µM/l) in experimental tanks during 60 days. The broodstock were fed by commercial shrimp diet, ad libitum, twice a day. The results revealed that reproductive activities ceased when Pb levels were 0.072 and 0.12 µM/l and also when Cd levels reached 0.08 µM/l. At 0.024 µM/l Pb, 0.026 and 0.053 µM/l Cd, the prawns showed initial reproductive activity but after spawning, the egg-clutches were found detached from the pleopods of the brood females. Hemato-immunology results showed that by increasing the Pb and Cd concentrations, large granular hemocyte (LGH) and cHH values also increased. However, small granular hemocyte (SGH) count was inversely affected. A significant increase in mortality (P < 0.05) was observed as both Pb and Cd concentrations increased. Histological observations are indicative of increased necrosis, lumen size, melanization, vacuolation and abnormal lumen shape, as the heavy metals concentrations increased. In conclusion, obtained results can help to elucidate effects of Pb and Cd on freshwater decapod crustaceans reproductive performance and related physiological parameters.


Assuntos
Cádmio/toxicidade , Chumbo/toxicidade , Palaemonidae/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Cádmio/administração & dosagem , Relação Dose-Resposta a Droga , Esquema de Medicação , Chumbo/administração & dosagem , Poluentes Químicos da Água/administração & dosagem
16.
Regul Toxicol Pharmacol ; 106: 68-80, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31028799

RESUMO

Fluoride (F-), a harmful compound if present in high concentration, is typically found in groundwater. It is important to investigate the F- concentrations in groundwaters of areas where individuals use groundwater for drinking purposes. The objectives of this study were: (a) to estimate the F- exposure, and (b) to assess the non-carcinogenic risk through consumption of groundwater among urban population (different age groups) of Agra city. A total of 28 groundwater samples were collected from Agra city in May 2016, which comprised 22 samples from hand pump and 6 samples from tube wells from shallow aquifers at different sites. The F- concentrations varied from 0.90 to 4.12 mg/L with an average value of 1.88 mg/L. The results obtained reveal that about 64% of the samples exceeded the F- permissible limit of 1.5 mg/L. Nevertheless, 32% of the samples were well within the WHO drinking water guidelines and 3.5% of the samples from the groundwater were below the 1.0 mg/L threshold. The maximum estimated exposure doses were 0.69, 0.31 and 0.12 mg/kg/day for infants, children and adults, respectively. A dental fluorosis becomes evident when the results obtained are compared with an oral reference dose of 0.06 mg/kg/day. The hazard quotient (HQ) was found to be more than 1 for infants and children in all the studied areas which indicates that young consumers are more vulnerable to non-carcinogenic risk due to exposure of F-. On the other hand, the adults at about 71% of the sampled sites may be victims of non-carcinogenic risk. From the results obtained in this study, it is recommended that there be implementation of the appropriate remediation for defluoridation of water to circumvent the population from the probable health risks of F-.


Assuntos
Monitoramento Ambiental , Fluoretos/análise , Água Subterrânea/química , Poluentes Químicos da Água/análise , Administração Oral , Criança , Pré-Escolar , Fluoretos/administração & dosagem , Fluoretos/efeitos adversos , Humanos , Índia , Lactente , Recém-Nascido , Medição de Risco , Poluentes Químicos da Água/administração & dosagem , Poluentes Químicos da Água/efeitos adversos
17.
Artigo em Inglês | MEDLINE | ID: mdl-31028930

RESUMO

Copper (Cu) and cadmium (Cd) are two kinds of abundant toxic metals in aquatic ecosystem. The present study evaluated the effects of waterborne Cu and Cd on oxidative stress responses and histological alterations in female rare minnow (Gobiocypris rarus). Fish were exposed for 7 days to: (i) control (no added Cu or Cd), (ii) waterborne Cu (39.2 µg L-1), (iii) waterborne Cd (299.6 µg L-1), and (iv) Cu and Cd in mixture (19.6 and 149.8 µg L-1, respectively). Antioxidant enzyme activities and gene mRNA abundance in fish tissues (gills, liver, and ovaries) were induced by Cu and Cd exposures, both individually and in mixture, at day 1, but an asynchronous response was observed between most enzyme activities and gene mRNA abundance following 7 days exposure. Biochemical analysis and histological observation indicated that exposure to Cu and Cd, alone and in combination, caused evident damage to lipids and tissue structure in gills, liver and ovaries. Comparing with single Cu or Cd exposure, Cu and Cd co-exposure induced greater increase in the mRNA expression of most antioxidant genes and caused more severe lesions in fish tissues, which suggested that exposure to waterborne Cu and Cd in mixture might increase their individual toxicity. Furthermore, positive relationships between nuclear factor erythroid 2-related factor (Nrf2) expression and expression of manganese superoxide dismutase (Mn-SOD) and catalase (CAT) were also observed in the present study, which suggested that Cu or/and Cd induced expression of these antioxidant genes were might through activation of Nrf2.


Assuntos
Cádmio/toxicidade , Cobre/toxicidade , Cyprinidae/fisiologia , Doenças dos Peixes/induzido quimicamente , Estresse Oxidativo/efeitos dos fármacos , Animais , Cádmio/administração & dosagem , Cobre/administração & dosagem , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Brânquias/efeitos dos fármacos , Glutationa , Fígado/efeitos dos fármacos , Malondialdeído , Ovário/efeitos dos fármacos , Testes de Toxicidade , Poluentes Químicos da Água/administração & dosagem , Poluentes Químicos da Água/toxicidade
18.
Regul Toxicol Pharmacol ; 106: 43-49, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31026539

RESUMO

Volatilization volumes and health risks associated with indirect inhalation exposure to formaldehyde evaporated from water have not been investigated quantitatively. We experimentally investigated formaldehyde volatility, compared with chloroform volatility, predicted formaldehyde inhalation exposure concentrations in Japanese bathrooms, and then re-evaluated drinking water quality standards. Although the Henry's law constant of formaldehyde is 1/104 that of chloroform, with a 30-min exposure period, the formaldehyde non-equilibrium partition coefficient (K'd) was 1/500th the chloroform value because of formaldehyde's faster volatilization rate. We used this ratio to estimate the cumulative probability distribution of formaldehyde concentrations in bathroom air. For a formaldehyde concentration in water of ≤2.6 mg/L-water (WHO tolerable concentration), the probability that the incremental formaldehyde concentration due to volatilization would exceed 100 µg/m3-air (WHO indoor air quality guideline) was low. However, major sources of formaldehyde in indoor air are building materials and furniture. We therefore calculated the allowable concentration in water by allocating a small percentage of the indoor air guideline value to indirect inhalation exposure via volatilization from tap water. With an allocation factor of 20% (10%), the allowable concentration was 0.52 (0.26) mg/L-water. These concentrations are similar to the Health Canada guideline concentration but they are 3-6 times the Japanese water quality standard.


Assuntos
Poluição do Ar em Ambientes Fechados/análise , Exposição Ambiental/análise , Formaldeído/análise , Exposição por Inalação , Poluentes Químicos da Água/análise , Água/química , Clorofórmio/administração & dosagem , Clorofórmio/análise , Formaldeído/administração & dosagem , Humanos , Japão , Medição de Risco , Volatilização , Poluentes Químicos da Água/administração & dosagem
19.
Environ Sci Pollut Res Int ; 26(14): 14106-14115, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30852756

RESUMO

Environmentally mediated sensitivity of Lemna minor to copper (Cu) was evaluated for the first time in three experiments: the effects of two levels of nutrient concentration, light irradiance or Cu pre-exposure were tested. Various Cu concentrations (ranging from 0.05 to 0.25 mg/L) were used to assess the sensitivity of L. minor to this metal, using one common strain previously acclimatized to two different levels of light intensity, nutrient enrichment and Cu pre-exposure. Our results showed a phenotypic plastic response of the relative growth rates based on frond number and fresh mass production, and maximum quantum yield of photosystem II (Fv/Fm). Growth was affected by the three environmental conditions both prior and during Cu exposure, whereas Fv/Fm was mostly affected during Cu exposure. Copper significantly influenced all the parameters measured in the three experiments. Environmental conditions significantly modified L. minor sensitivity to Cu in all experiments, with up to twofold difference depending on the treatment. Growth rate was the parameter that was most impacted. Our study revealed for the first time the existence of phenotypic plasticity in L. minor sensitivity to chemical contamination, and implies that environmental context needs to be taken into account for a relevant risk assessment.


Assuntos
Araceae/efeitos dos fármacos , Araceae/fisiologia , Cobre/toxicidade , Poluentes Químicos da Água/toxicidade , Aclimatação , Cobre/administração & dosagem , Ecotoxicologia/métodos , Luz , Fenótipo , Complexo de Proteína do Fotossistema II/metabolismo , Poluentes Químicos da Água/administração & dosagem
20.
Chem Res Toxicol ; 32(5): 869-877, 2019 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-30807115

RESUMO

Acrylamide has been classified as a "Group 2A carcinogen" (probably carcinogenic to humans) by the International Agency for Research on Cancer. The carcinogenicity of acrylamide is attributed to its well-recognized genotoxicity. In the present study, we investigated the effect of acrylamide on epigenetic alterations in mice. Female B6C3F1 mice received acrylamide in drinking water for 28 days, at doses previously used in a 2 year cancer bioassay (0, 0.0875, 0.175, 0.35, and 0.70 mM), and the genotoxic and epigenetic effects were investigated in lungs, a target organ for acrylamide carcinogenicity, and livers, a nontarget organ. Acrylamide exposure resulted in a dose-dependent formation of N7-(2-carbamoyl-2-hydroxyethyl)guanine and N3-(2-carbamoyl-2-hydroxyethyl)adenine in liver and lung DNA. In contrast, the profiles of global epigenetic alterations differed between the two tissues. In the lungs, acrylamide exposure resulted in a decrease of histone H4 lysine 20 trimethylation (H4K20me3), a common epigenetic feature of human cancer, while in the livers, there was increased acetylation of histone H3 lysine 27 (H3K27ac), a gene transcription activating mark. Treatment with 0.70 mM acrylamide also resulted in substantial alterations in the DNA methylation and whole transcriptome in the lungs and livers; however, there were substantial differences in the trends of DNA methylation and gene expression changes between the two tissues. Analysis of differentially expressed genes showed a marked up-regulation of genes and activation of the gene transcription regulation pathway in livers, but not lungs. This corresponded to increased histone H3K27ac and DNA hypomethylation in livers, in contrast to hypermethylation and transcription silencing in lungs. Our results demonstrate that acrylamide induced global epigenetic alterations independent of its genotoxic effects, suggesting that epigenetic events may determine the organ-specific carcinogenicity of acrylamide. Additionally this study provides strong support for the importance of epigenetic alterations, in addition to genotoxic events, in the mechanism of carcinogenesis induced by genotoxic chemical carcinogens.


Assuntos
Acrilamida/toxicidade , Adutos de DNA/metabolismo , Fígado/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Mutagênicos/toxicidade , Poluentes Químicos da Água/toxicidade , Acrilamida/administração & dosagem , Adenina/análogos & derivados , Adenina/química , Administração Oral , Animais , Carcinógenos/administração & dosagem , Carcinógenos/toxicidade , Adutos de DNA/química , Adutos de DNA/genética , Epigênese Genética/efeitos dos fármacos , Feminino , Guanina/análogos & derivados , Guanina/química , Histonas/química , Histonas/genética , Histonas/metabolismo , Metilação/efeitos dos fármacos , Camundongos , Mutagênicos/administração & dosagem , Poluentes Químicos da Água/administração & dosagem
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