Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 27
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Environ Toxicol Pharmacol ; 104: 104313, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37972914

RESUMO

When silica nanoparticles (SiNP) reach the water bodies interact with the already existing pollutants in the environments. This study aimed to evaluate the ecotoxicity of SiNP under the presence/absence of Cu in mosquitofish (Gambusia holbrooki). Fish were exposed to 0, 10 and 100 mg SiNP L-1, alone or mixed with Cu (0.25 mg L-1). After 96 h, the amount of colony forming units (CFU) of bacteria living on the skin mucus was analysed, and oxidative stress, tissue damage enzymes, and neurotoxicity were evaluated. We observed a reduction in CFU when Cu was present in the media. The liver was the target organ, evidencing a decrease in tissue damage enzymatic activities, activation of the antioxidant system in all treatments, and lipid oxidative damage when the SiNP and Cu were mixed. Overall, SiNP ecotoxicity was proved, which could also be enhanced by the presence of ubiquitous elements such as metals.


Assuntos
Ciprinodontiformes , Poluentes Químicos da Água , Animais , Cobre/toxicidade , Estresse Oxidativo , Antioxidantes , Ciprinodontiformes/fisiologia , Poluentes Químicos da Água/toxicidade
2.
Environ Toxicol Pharmacol ; 102: 104238, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37524194

RESUMO

Silica nanoparticles (SiNP) are the most produced nanomaterials due to their variety of applications. When released to environments, surface water bodies are their main final sink. SiNP toxicity is still inconclusive and may vary according to particle properties such as their size. We analyzed the size-related effects of SiNP (22 and 244 nm) on mortality, life history traits, and oxidative stress in the cladoceran Ceriodaphnia reticulata. The smaller SiNP (LC5072 h: 105.5 µg/ml) were more lethal than the larger ones (LC5072 h >500 µg/ml). The 22 nm-sized SiNP decreased the number of molts and neonates, increased superoxide dismutase and inhibited glutathione S-transferase activities, while larger SiNP did not exert substantial effects on the organisms at the tested concentrations. In conclusion, SiNP toxicity depended on their size, and this information should be considered for regulatory purposes and to the development of safe-by-design nanoproducts to ultimately guarantee the environment protection.


Assuntos
Cladóceros , Nanopartículas , Animais , Humanos , Recém-Nascido , Nanopartículas/toxicidade , Estresse Oxidativo , Superóxido Dismutase , Dióxido de Silício/toxicidade
3.
Toxicol Appl Pharmacol ; 471: 116560, 2023 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-37230195

RESUMO

The imminent increase in global food demand inevitably leads to an increase in agricultural practices, with an emphasis on pesticide applications. Nanotechnology-based pesticides, or nanopesticides, have gained importance as they are more efficient and, in some cases, less toxic than their conventional counterparts. However, concerns about these novel products have arisen as evidence about their (eco)safety is controversial. This review aims to: (1) introduce the currently applied nanotechnology-based pesticides and their mechanisms of toxic action; (2) describe their fate when released into the environment, with an emphasis on aquatic environments; (3) summarize available research on ecotoxicological studies in freshwater non-target organisms through a bibliometric analysis; and (4) identify gaps in knowledge from an ecotoxicological perspective. Our results show that the environmental fate of nanopesticides is poorly studied and depends on both intrinsic and external factors. There is also a need for comparative research into their ecotoxicity between conventional pesticide formulations and their nano-based counterparts. Among the few available studies, most considered fish species as test organisms, compared to algae and invertebrates. Overall, these new materials generate toxic effects on non-target organisms and threaten the integrity of the environment. Therefore, deepening the understanding of their ecotoxicity is crucial.


Assuntos
Praguicidas , Poluentes Químicos da Água , Animais , Praguicidas/toxicidade , Nanotecnologia , Peixes , Agricultura , Poluentes Químicos da Água/toxicidade
4.
Environ Sci Pollut Res Int ; 30(10): 27137-27149, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36378381

RESUMO

Silver nanoparticles (AgNPs) are applied in diverse industries due to their biocide and physicochemical properties; therefore, they can be released into aquatic systems, interact with environmental factors, and ultimately exert adverse effects on the biota. We analyzed AgNPs effects on Ceriodaphnia reticulata (Cladocera) through mortality and life-history traits, considering the influence of food (Tetradesmus obliquus, Chlorophyceae) presence and concentration. C. reticulata was exposed to AgNPs in acute (absence and two algae concentrations plus five AgNPs treatments) and chronic assays (two algae concentrations plus three AgNPs treatments). AgNPs did not affect algae flocculation but increased Ag+ release, being these ions less toxic than AgNPs (as proved by the exposure to AgNO3). A reduction in AgNPs acute toxicity was observed when algae concentration increased. Acute AgNP exposure decreased C. reticulata body size and heart rate. The chronic AgNP exposure reduced C. reticulata molt number, growth, heart rate, and neonate size:number ratio, being these effects mitigated at the highest algae concentration. Increases in relative size and number of neonates were observed in AgNP treatments suggesting energy trade off. The increased Ag+ release with food presence suggests that the AgNP-algae interaction might be responsible of the decreased toxicity. Although algae reduced AgNP toxicity, they still exerted adverse effects on C. reticulata below predicted environmental concentrations. Since algae presence reduces AgNP effects but increases Ag+ release, studies should be continued to provide evidence on their toxicity to other organisms.


Assuntos
Clorofíceas , Cladóceros , Nanopartículas Metálicas , Animais , Humanos , Recém-Nascido , Nanopartículas Metálicas/toxicidade , Nanopartículas Metálicas/química , Prata/toxicidade , Prata/química
6.
Environ Pollut ; 304: 119237, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35367505

RESUMO

Farmland birds can be exposed to neonicotinoids through the ingestion of treated unburied seeds and cotyledons. The aim of this study was to evaluate the avoidance of sorghum with imidacloprid, clothianidin or thiamethoxam, soybean with imidacloprid, and soybean cotyledons with imidacloprid or thiamethoxam on eared doves (Zenaida auriculata). Doves were fed with test food (untreated and neonicotinoid-treated sorghum, soybean or soybean cotyledons) and maintenance food (seed mix) for 3-5 days to study the repellency (primary repellency and conditioned aversion) and anorexia caused by neonicotinoid-treated food, followed by a 7-day period on maintenance food to study the persistence of the anorexic effect after neonicotinoid exposure. Immediately afterward, the same doves were exposed to treated test food during a second period of 3-5 days to study the potential reinforcement of food avoidance. Finally, doves were fed with untreated test food to test the capacity of the pesticide to induce conditioned food aversion against untreated food in subsequent encounters. Intoxication signs and differences of body weight were determined. With sorghum, the three neonicotinoids produced a decrease in the consumption of treated seeds by >97% compared to control birds. However, this was not enough to prevent the death of 3/8 and 1/8 of the doves exposed to imidacloprid and clothianidin, respectively. Anorexia was clearly observed with neonicotinoid-treated sorghum. The birds did not avoid the untreated sorghum after exposure to the treated sorghum, indicating that avoidance is not generalized to the type of food without an associated sensory cue. The results obtained with soybean seeds and cotyledons were less conclusive because captive doves hardly consumed these foods, even without neonicotinoid treatment. The avoidance of sorghum seeds treated with neonicotinoids was insufficient to prevent poisoning and death of eared doves.


Assuntos
Columbidae , Inseticidas , Animais , Anorexia , Cotilédone/química , Grão Comestível/química , Inseticidas/análise , Inseticidas/toxicidade , Neonicotinoides/toxicidade , Nitrocompostos/análise , Nitrocompostos/toxicidade , Sementes/química , Tiametoxam
7.
Front Bioeng Biotechnol ; 10: 836742, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35350188

RESUMO

Nanotechnologies have rapidly grown, and they are considered the new industrial revolution. However, the augmented production and wide applications of engineered nanomaterials (ENMs) and nanoparticles (NPs) inevitably lead to environmental exposure with consequences on human and environmental health. Engineered nanomaterial and nanoparticle (ENM/P) effects on humans and the environment are complex and largely depend on the interplay between their peculiar properties such as size, shape, coating, surface charge, and degree of agglomeration or aggregation and those of the receiving media/body. These rebounds on ENM/P safety and newly developed concepts such as the safety by design are gaining importance in the field of sustainable nanotechnologies. This article aims to review the critical characteristics of the ENM/Ps that need to be addressed in the safe by design process to develop ENM/Ps with the ablility to reduce/minimize any potential toxicological risks for living beings associated with their exposure. Specifically, we focused on silver nanoparticles (AgNPs) due to an increasing number of nanoproducts containing AgNPs, as well as an increasing knowledge about these nanomaterials (NMs) and their effects. We review the ecotoxicological effects documented on freshwater and marine species that demonstrate the importance of the relationship between the ENM/P design and their biological outcomes in terms of environmental safety.

8.
Water Environ Res ; 93(11): 2505-2526, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34470080

RESUMO

In this article, we performed a literature review on the metallic, metal oxide, and metalloid nanoparticles (NP) effects on freshwater microcrustaceans, specifically focusing on (i) the main factors influencing the NP toxicity and (ii) their main ecotoxicological effects. Also, given that most studies are currently developed on the standard test species Daphnia magna Straus, we analyzed (iii) the potential differences in the biological responses between D. magna and other freshwater microcrustacean, and (iv) the ecological implications of considering only D. magna as surrogate of other microcrustaceans. We found that NP effects on microcrustaceans depended on their intrinsic properties as well as the exposure conditions. Among the general responses to different NP, we identified body burial, feeding inhibition, biochemical effects, metabolic changes, and reproductive and behavioral alterations. The differences in the biological responses between D. magna and other freshwater microcrustacean rely on the morphology (size and shape), ecological traits (feeding mechanisms, life cycles), and intrinsic sensitivities. Thus, we strongly recommend the use of microcrustaceans species with different morphological, physiological, and ecological characteristics in future ecotoxicity tests with NP to provide relevant information with regulation purposes regarding the discharge of NP into aquatic environments. PRACTITIONER POINTS: Nanoparticles effects depend on intrinsic and external factors. Nanoparticles affect the morphology, physiology, and behavior. Effects on Daphnia differ from other microcrustaceans. The use of more diverse test species is suggested.


Assuntos
Nanopartículas Metálicas , Metaloides , Nanopartículas , Poluentes Químicos da Água , Animais , Daphnia , Água Doce , Nanopartículas Metálicas/toxicidade , Óxidos , Poluentes Químicos da Água/toxicidade
9.
Environ Toxicol Pharmacol ; 87: 103689, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34144182

RESUMO

This review aims to (i) provide a current overview of the main characteristics of SiNP (physical and chemical properties, applications, and emissions), (ii) evaluate the scientific production up to date concerning SiNP, with focus on their toxic effects, through a bibliometric analysis, (iii) describe the main toxic mechanisms of SiNP, (iv) assess the current knowledge about ecotoxicity of SiNP on aquatic organisms (marine and freshwater), and (v) identify the main gaps in the knowledge of SiNP toxicity from an environmentally point of view. The scientific production of SiNP concerning their chemical and physical characteristics has increased exponentially. However, little information is available regarding their ecotoxicity. Particle functionalization is a key factor that reduces SiNP toxicity. Most of the studies employed standard species as test organisms, being the local/native ones poorly represented. Further studies employing long-term exposures and environmentally relevant concentrations are needed to deepen the knowledge about this emergent pollutant.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Nanopartículas/toxicidade , Dióxido de Silício/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Bibliometria , Humanos
10.
Bull Environ Contam Toxicol ; 107(3): 421-426, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33974084

RESUMO

Silver nanoparticles (AgNP) are unique because of their biocide properties. Once released to environment, AgNP interact with the natural organic matter which impact on their fate, dispersion, and ultimate toxicity. We carried out an ex vivo exposure of gill of Corydoras paleatus fish to 100 µg L-1 of AgNP or AgNO3, alone and in combination with 10 mg L-1 of humic acids (HA), with the aim to evaluate the potential mitigation of HA on AgNP toxic effects. We analyzed Ag accumulation and oxidative stress biomarkers. The results showed high bioaccumulation after the AgNO3+HA exposure. An inhibition of glutathione-S-transferase enzymatic activity and depletion of reduced glutathione levels were registered after the AgNO3 exposure, and increased lipid peroxidation levels in the case of AgNP one. Oxidative responses were mitigated when the HA were present in the media. Overall, the knowledge about the fate of this emergent pollutant was deepened through this study.


Assuntos
Nanopartículas Metálicas , Nitrato de Prata , Animais , Brânquias , Substâncias Húmicas , Nanopartículas Metálicas/toxicidade , Prata/toxicidade , Nitrato de Prata/toxicidade
11.
Environ Pollut ; 287: 117356, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34020257

RESUMO

Fish cultivation in rice fields is a valuable resource in some rural areas of the world. Fish is a source of protein and an additional source of income for local farmers. However, the use of pesticides may impact fish and consumer health. The aim of this study was to evaluate exposure and effect biomarkers in native fish inhabiting a rice field during a production cycle. Samples of fish, water and sediment from a rice field in Santa Fe, Argentina were collected during a cultivation season (at the beginning: November 2017, in the middle: December 2017 and at the end: February 2018). At each sampling period, fish biomarkers of effect (biometric indices, hematological parameters, energy reserves, oxidative stress and neurotoxicity) were assessed together with pesticide screening in water, sediment, and fish samples. Only herbicides were present in water and sediment samples in agreement with land treatment before rice sowing stage, where only herbicides were applied. In general, the greatest water concentrations of bentazone, glyphosate and aminomethylphosphonic acid (AMPA), and the lowest sediment glyphosate and AMPA levels were observed at the beginning of the farming cycle. Fish bioaccumulated AMPA residues at all sampling periods and showed biological responses to cope with a stressful environment. Alterations in hematological parameters, mobilization of energetic reserves and activation of the antioxidant system were detected. However, no oxidative damage nor neurotoxic effects were present along the production cycle. Under a real exposure scenario, the present work demonstrates that biological changes are induced in fish to cope with stressors present in a rice field. Fish-rice coculture is an efficient and ecologically sustainable approach to increase food supplies, and a better understanding of the effect of this particular environment on fish would allow a greater and safer development of this promising productive activity in South American rice producing countries.


Assuntos
Peixes-Gato , Herbicidas , Oryza , Poluentes Químicos da Água , Animais , Biomarcadores , Monitoramento Ambiental , Herbicidas/análise , Organofosfonatos , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
12.
Fish Physiol Biochem ; 47(4): 829-839, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33723682

RESUMO

This study aimed to analyze the cold stress effects (in terms of hematology, energy reserves, and oxidative stress) in Piaractus mesopotamicus (pacú) and their mitigation by a Pyropia columbina red seaweed-supplemented diet. For this purpose, juvenile fish were fed with a control (CD) or a red seaweed-supplemented diet (RD) for 60 days, and then, the animals were exposed to a low temperature (14 °C) and a control temperature (24 °C) for 24 h. The cold shock generated an increase of hemoglobin levels in fish fed with both diets. In CD-fed fish, plasmatic triglycerides, cholesterol, and hepatic glycogen decreased after the thermal shock; meanwhile, the animals fed with RD showed decreased hepatic proteins, but increased cholesterol and hepatic glycogen. Regarding oxidative stress, antioxidant enzymes augmented their activity in the liver, intestine, and gills; meanwhile, lipid oxidative damage was observed in the liver and intestine of fish exposed to 14 °C and fed with both diets. Pacú was sensitive to cold shock, but no mitigation effects were observed in fish fed with the supplemented diet. Further research should target higher concentrations of P. columbina in supplemented diets to take advantage of this valuable resource.


Assuntos
Caraciformes , Resposta ao Choque Frio , Suplementos Nutricionais , Rodófitas , Alga Marinha , Animais , Caraciformes/sangue , Caraciformes/metabolismo , Dieta , Proteínas de Peixes/metabolismo , Brânquias/metabolismo , Glutationa Redutase/metabolismo , Glutationa Transferase/metabolismo , Glicogênio/metabolismo , Mucosa Intestinal/metabolismo , Metabolismo dos Lipídeos , Fígado/metabolismo , Músculos/metabolismo , Estresse Oxidativo , Superóxido Dismutase/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
13.
Environ Sci Pollut Res Int ; 28(24): 31659-31669, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33608791

RESUMO

Silver nanoparticles (AgNPs) are one of the most produced nanoproducts due to their unique biocide properties. The natural organic matter has an important impact on nanoparticle's dispersion as it may alter their fate and transport, as well as their bioavailability and toxicity. Therefore, this study aimed to evaluate the mitigatory effect of humic acids (HAs) on AgNP toxicity. For this purpose, we carried out an ex vivo exposure of gill of Piaractus mesopotamicus fish to 100 µg L-1 of AgNPs or AgNO3, alone and in combination with 10 mg L-1 of HAs. In parallel, a complete AgNP characterization in the media, including the presence of HAs, was provided, and the Ag+ release was measured. We analyzed Ag bioaccumulation, antioxidant enzymes activities, lipid peroxidation, antioxidant capacity against peroxyl radicals, and reduced glutathione levels in fish tissue. Our results indicated the Ag+ release from AgNPs decreased 28% when the HAs were present in the media. The Ag accumulation in gill tissue exposed to AgNPs alone was higher than the AgNO3 exposure, and sixfold higher than the treatment with the HA addition. Moreover, after both Ag forms, the catalase enzyme augmented its activity. However, those responses were mitigated when the HAs were present in the media. Then, our results suggested the mitigation by HAs under the exposure to both Ag forms, providing valuable information about the fate and behavior of this emergent pollutant.


Assuntos
Nanopartículas Metálicas , Poluentes Químicos da Água , Animais , Brânquias/química , Substâncias Húmicas , Nanopartículas Metálicas/toxicidade , Prata/análise , Poluentes Químicos da Água/análise
14.
J Therm Biol ; 88: 102497, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32125985

RESUMO

This study investigated the effects of cold stress on morphometrical and hematological biomarkers, energy metabolism, and oxidative stress in different tissues of P. mesopotamicus, and the protective role of ß-carotene. Fish were fed with a control diet (CD) and the same diet supplemented with 105 mg/kg ß-carotene (BD) for 60 days. After the feeding trial, fish fed CD or BD diets were exposed to control (24 °C) and low temperature (14 °C) for 24 h. Fish (CD and BD) exposed to thermal stress showed lower hepatosomatic index. The hemoglobin increased only in CD-fed fish exposed to 14 °C. Increased glycemia, plasmatic protein depletion, and decreased hepatic glycogen were observed in fish fed the CD, while only the lipid levels in liver were augmented in BD-fed fish exposed at 14 °C. Regarding the oxidative stress, increased antioxidant enzymes activity and lipid peroxidation were observed in CD-fed fish exposed to cold. The two-way ANOVA showed an interaction between dietary treatment and temperature for glucose and oxidative stress biomarkers, with the highest values recorded in 14 °C-exposed fish fed with the CD. Our study demonstrated that cold stress had the greatest impact on fish oxidative status, and ß-carotene reduces harmful effects induced by cold in P. mesopotamicus.


Assuntos
Antioxidantes/farmacologia , Caraciformes/fisiologia , Resposta ao Choque Frio/efeitos dos fármacos , Suplementos Nutricionais , beta Caroteno/farmacologia , Animais , Peroxidação de Lipídeos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos
15.
Curr Pharm Des ; 25(37): 3927-3942, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31512995

RESUMO

The increasing production and use of nanoparticles (NP) have raised concerns regarding the potential toxicity to human and environmental health. In this review, we address the up to date information on nanotoxicity using fish as models. Firstly, we carried out a systematic literature search (articles published up to February 2019 in the Scopus database) in order to quantitatively assess the scientific research on nanoparticles, nanotoxicity and fish. Next, we carried out a narrative synthesis on the main factors and mechanisms involved in NP toxicity in fish. According to the bibliometric analysis, there is a low contribution of scientific research on nanotoxicity compared with the general nanoparticles scientific production. The literature search also showed that silver and titanium NP are the most studied nanomaterials and Danio rerio is the fish species most used. In comparison with freshwater fish, the effects of nanomaterials on marine fish have been little studied. After a non-systematic literature analysis, we identified several factors involved in nanotoxicity, as well as the effects and main toxicity mechanisms of NP on fish. Finally, we highlighted the knowledge gaps and the need for future research.


Assuntos
Nanopartículas Metálicas/toxicidade , Nanopartículas/toxicidade , Peixe-Zebra , Animais , Prata , Titânio , Testes de Toxicidade
16.
Aquat Toxicol ; 211: 46-56, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30946994

RESUMO

The incorporation of silver nanoparticles (AgNPs) in commercial products is increasing rapidly. The consequent release of AgNPs into domestic and industrial wastewater raises environmental concerns due to their anti-microbial properties and toxicity to non-target aquatic organisms. The aim of the present study was to investigate the effects of nanArgen™ (Nanotek S.A.), a AgNP-enabled consumer product, in the marine bivalve Mytilus galloprovincialis. Two environmentally relevant concentrations of nanArgen™ (1 and 10 µg/L) were tested in vivo for 96 h, and Ag was quantified in mussel soft tissue and natural seawater (NSW). nanArgen™ suspensions were characterized via TEM, SEM, EDS, DLS, and UV-vis optical analysis. Several molecular and biochemical responses were investigated in exposed mussels: lysosomal membrane stability by Neutral Red Retention Time (NRRT) assay; micronucleus (MN) frequency in hemocytes; metallothionein (MT) protein content and gene expression (mt10 and mt20); catalase (CAT) and glutathione-S-transferase (GST) activities; malondialdehyde (MDA) accumulation in digestive glands; and efflux activity of ATP-binding cassette transport proteins (ABC) in gill biopsies. SEM, TEM and DLS analyses confirmed the presence of well-defined AgNPs in nanArgen™ which were roughly spherical with an average particle size of approx. 30 ± 10 nm. DLS analysis revealed the formation of AgNP aggregates in nanArgen™ suspension in NSW (Z-average of 547.80 ± 90.23 nm; PDI of 0.044). A significant concentration-dependent accumulation of Ag was found in mussels' whole soft tissue in agreement with a concentration-dependent decrease in NRRT and an increase of MN frequency in hemocytes and GST activities in digestive glands. A significant increase in MDA levels and MT via both molecular and biochemical tests, were also observed but only at the highest nanArgen™ concentration (10 µg/L). No changes were observed in CAT activities. ABC efflux activities in gill biopsies showed a significant decrease (p < 0.05) only at the lowest concentration (1 µg/L). On such basis, nanArgen™ is shown to be able to induce toxicity and Ag accumulation in marine mussels similarly to AgNPs and in short-term exposure conditions at environmentally relevant concentrations. AgNP-enabled products, instead of pristine AgNPs, should be the focus of future ecotoxicity studies in order to address any risks associated to their widespread use, disposal and uncontrolled release into the aquatic environment for non target species.


Assuntos
Nanopartículas Metálicas/toxicidade , Mytilus/efeitos dos fármacos , Prata/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Catalase/metabolismo , Relação Dose-Resposta a Droga , Brânquias/química , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Hemócitos/efeitos dos fármacos , Hemócitos/patologia , Lisossomos/efeitos dos fármacos , Nanopartículas Metálicas/análise , Metalotioneína/metabolismo , Micronúcleos com Defeito Cromossômico/induzido quimicamente , Mytilus/química , Mytilus/metabolismo , Água do Mar/química , Prata/análise , Poluentes Químicos da Água/análise
17.
Acta toxicol. argent ; 23(2): 73-78, set. 2015. ilus, graf
Artigo em Espanhol | LILACS | ID: biblio-837840

RESUMO

El uso creciente de nanomateriales en productos industriales y de consumo ha incrementado la preocupación mundial respecto a sus posibles efectos adversos en los sistemas biológicos. Como consecuencia de la falta de un marco legislativo y la ausencia de un consenso sobre los protocolos experimentales, las investigaciones ecotoxicológicas se llevan a cabo a un ritmo mucho más lento que la producción de nuevas nanopartículas. Por esta razón, existe una necesidad creciente de realizar estudios que aporten conocimiento sobre el riesgo de estos contaminantes emergentes de propiedades únicas. El objetivo del presente trabajo fue evaluar la frecuencia de micronúcleos (FMN) en eritrocitos de ejemplares juveniles de pacú (Piaractus mesopotamicus) expuestos a nanopartículas de plata (Nano-Ag) a las concentraciones de 0 μg·L-1 (control); 2,5 μg·L-1; 10 μg·L-1; y 25 μg·L-1, durante 24 horas. Se observó que la FMN se incrementó significativamente (p<0,01) en la concentración de 25 μg·L-1, mientras que no hubo diferencias significativas entre los grupos expuestos a 2,5 y 10 μg·L-1 y el control. Estos resultados sugieren que los eventos aneugénicos o clastogénicos podrían representar un posible mecanismo de toxicidad de Nano-Ag en esta especie.


The growing use of nanomaterials in consumer and industrial products has aroused global concern about possible adverse effects on biological systems. Due to the lack of a regulation framework and the absence of a consensus on the experimental protocols, ecotoxicological investigations are carried out much slower than the production of new nanoparticles. For this reason, there is a growing need for studies that provide knowledge about the risk of these emerging contaminants of unique properties. The objective of the present study was to evaluate the frequency of micronuclei (FMN) in erythrocytes of juvenile Piaractus mesopotamicus exposed to silver nanoparticles (nano-Ag; Nanotek SA) at concentrations of 0 μg·L-1 (control); 2.5 μg·L-1; 10 μg·L-1; and 25 μg·L-1, for 24 hours (n = 10 per treatment). The FMN show a significant increase (p <0.01) in fish exposed to 25 μg·L-1 of Nano-Ag, while there were no significant differences among the groups exposed to 2.5 and 10 μg·L-1 with the control. These results suggest that the aneugenics or clastogenics events may represent a possible mechanism of toxicity of Nano-Ag in this specie.


Assuntos
Nanopartículas Metálicas/toxicidade , Testes para Micronúcleos/métodos , Microscopia Eletrônica de Transmissão/métodos , Testes de Mutagenicidade/estatística & dados numéricos
18.
Fish Physiol Biochem ; 38(3): 693-702, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21850399

RESUMO

This study evaluated the histopathological changes in gills and liver of Prochilodus lineatus inhabiting the Salado River basin. Fish were collected in four different sampling stations. The histological lesions in the tissues were examined under light microscopy and evaluated with quantitative analyses. The morphometric analysis of the gills showed a significant shortening of secondary lamellae and a lower percentage of area for gas exchange in fish from station 1 (an urban area, located near the mouth of the Salado River) in comparison with fish gills from the reference site (station 4, a relatively pristine area). Moreover, a significantly higher area occupied with necrotic foci and the occurrence of an important inflammatory response were observed in fish liver of station 1 than the samples caught from other stations. Thus, histopathological evidences showed differences among sites, which could be related to different environmental conditions.


Assuntos
Caraciformes/anatomia & histologia , Brânquias/patologia , Fígado/patologia , Animais , Argentina , Monitoramento Ambiental , Rios/química , Estresse Fisiológico , Poluição Química da Água/efeitos adversos , Poluição Química da Água/análise
19.
Arch Environ Contam Toxicol ; 61(3): 453-60, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21221961

RESUMO

Median lethal concentration (LC(50)) and sublethal effects of the commercial endosulfan formulation Zebra Ciagro(®) on the fish Cichlasoma dimerus were studied. The 96-h LC(50) was estimated as 17.7 µg/L. In order to investigate sublethal effects, fish were exposed to 25% and 50% LC(1) (3.4 and 6.8 µg/L, respectively). Endosulfan (ED) significantly increased the hemoglobin concentration and white blood cell count after 96 h. Differential leukocytes count was also altered, due to an increase in the percentage of neutrophils in exposed fish. The hepatopancreatic tissue of fish under ED treatment showed a decrease in aspartate aminotransferase and alanine aminotransferase and an increase in alkaline phosphatase. Lipid peroxidation levels in the 6.8-µg/L ED-containing group were higher than those in control fish for all organs tested (gills, hepatopancreas, and brain).


Assuntos
Ciclídeos , Endossulfano/toxicidade , Monitoramento Ambiental/métodos , Inseticidas/toxicidade , Estresse Fisiológico/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Alanina Transaminase/efeitos dos fármacos , Alanina Transaminase/metabolismo , Fosfatase Alcalina/efeitos dos fármacos , Fosfatase Alcalina/metabolismo , Animais , Aspartato Aminotransferases/efeitos dos fármacos , Aspartato Aminotransferases/metabolismo , Encéfalo/efeitos dos fármacos , Endossulfano/análise , Brânquias/efeitos dos fármacos , Hemoglobinas/análise , Hemoglobinas/efeitos dos fármacos , Inseticidas/análise , Dose Letal Mediana , Contagem de Leucócitos , Fígado/efeitos dos fármacos , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Poluentes Químicos da Água/análise
20.
Environ Pollut ; 157(11): 3025-33, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19589632

RESUMO

This field study assessed water quality of Salado River basin by using a set of biomarkers in the fish Prochilodus lineatus. Multiple biomarkers were measured, including morphological indexes (condition factor, liver somatic index), hematological (red and white blood cells) and biochemical (glucose, total protein and cholinesterase activity) parameters. Besides, detoxication and oxidative stress markers (antioxidant enzymes, lipid peroxidation) were measured in liver, gills and kidney. Despite water quality assessment did not show marked differences among sites, biomarkers responses indicate that fish are living under stressful environmental conditions. According to multivariate analysis glucose, glutathione S-transferase activity, lipid peroxidation levels and the count of white blood cells are key biomarkers to contribute to discrimination of sites. So, we suggest use those biomarkers in future monitoring of freshwater aquatic systems.


Assuntos
Caraciformes/metabolismo , Monitoramento Ambiental/métodos , Rios/química , Poluição da Água/análise , Animais , Argentina , Biomarcadores/análise , Caraciformes/crescimento & desenvolvimento , Brânquias/química , Brânquias/metabolismo , Fígado/química , Fígado/metabolismo , Qualidade da Água
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...