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1.
Chemosphere ; 254: 126905, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957298

RESUMO

With the development of modern technologies, the exploitation and application of rare earth metals (REMs) have increased parallelly. Consequently, more REMs are entering into the environment and therefore there is a pressing need to assess their potential environmental hazards. Here, a standard toxicity test with wheat (Triticum aestivum) was conducted to investigate the single and mixture toxicity of La and Ce in solutions with different levels of calcium and nitrilotriacetic acid (NTA) and results were deciphered by different modeling approaches. Both La and Ce caused adverse effect to wheat, but the presence of Ca and NTA alleviated their toxicity. The obtained EC50 for [La] or [Ce] changed by more than 28-fold and by 4-fold, respectively, with the increase of Ca or NTA. The biotic ligand model (BLM) explained approximately 93% variation of single La or Ce toxicity. The binding constants obtained were 4.14, 6.67, and 6.59 for logKCaBL, logKLaBL, and logKCeBL respectively. The electrostatic toxicity model (ETM) was proved as effective as the BLM, with R2 = 0.93 for La and R2 = 0.92 for Ce. For La-Ce mixtures, parameters from single toxicity approaches were applied successfully to predict the mixture toxicity with concentration addition (CA) model based on the BLM or ETM theory (R2 = 0.92 and RMSE = 8.56; R2 = 0.90 and RMSE = 9.6, respectively). Thus, the results obtained in this study prove that both ETM and BLM theories are appropriate to predict single and mixture REMs toxicity, providing coherent and promising tools for the risk assessment of REM pollution.


Assuntos
Cálcio/química , Cério/toxicidade , Lantânio/toxicidade , Ácido Nitrilotriacético/química , Testes de Toxicidade/métodos , Triticum/efeitos dos fármacos , Ligantes , Modelos Teóricos , Soluções , Eletricidade Estática , Triticum/crescimento & desenvolvimento
2.
Ecotoxicol Environ Saf ; 203: 110991, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32888602

RESUMO

The stimulant and toxicity effects of reported organic (acetic acid, propionic acid, butyric acid, formic acid, oil & grease) and inorganic (copper) by-products presented in palm oil mill effluent on anaerobic bacterial population were examined in this paper. The toxicity test had shown that acetic, propionic and butyric acids tend to stimulate the bacterial density level (survival rate more than 50%), while formic acid, copper, oil and grease were shown to have suppressed the density level (survival rate less than 50%). The highest biomass recorded was 1.66 mg/L for the concentration of acetic acid at 216 mg/L and lowest biomass concentration, 0.90 mg/L for copper at 1.40 mg/L. Biohydrogen-producing bacteria have a favourable growth rate around pH 5.5. The comparison of half maximal effective concentration (EC50) values between two test duration on the effects of organic and inorganic by-products postulate that bacteria had a higher tolerance towards volatile fatty acids. While acetic, butyric and propionic acids had exhibited higher tolerance EC50 values for bacteria, but the opposite trend was observed for formic acid, copper and oil & grease.


Assuntos
Bactérias Anaeróbias/efeitos dos fármacos , Óleo de Palmeira/toxicidade , Testes de Toxicidade/métodos , Relação Dose-Resposta a Droga , Hidrogênio/metabolismo , Resíduos Industriais/análise
3.
Int J Nanomedicine ; 15: 6183-6200, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32922001

RESUMO

Purpose: Diethylaminoethyl-chitosan (DEAE-CH) is a derivative with excellent potential as a delivery vector for gene therapy applications. The aim of this study is to evaluate its toxicological profile for potential future clinical applications. Methods: An endotoxin-free chitosan (CH) modified with DEAE, folic acid (FA) and polyethylene glycol (PEG) was used to complex small interfering RNA (siRNA) and form nanoparticles (DEAE12-CH-PEG-FA2/siRNA). Based on the guidelines from the International Organization for Standardization (ISO), the American Society for Testing and Materials (ASTM), and the Nanotechnology Characterization Laboratory (NCL), we evaluated the effects of the interaction between these nanoparticles and blood components. In vitro screening assays such as hemolysis, hemagglutination, complement activation, platelet aggregation, coagulation times, cytokine production, and reactive species, such as nitric oxide (NO) and reactive oxygen species (ROS), were performed on erythrocytes, plasma, platelets, peripheral blood mononuclear cells (PBMC) and Raw 264.7 macrophages. Moreover, MTS and LDH assays on Raw 264.7 macrophages, PBMC and MG-63 cells were performed. Results: Our results show that a targeted theoretical plasma concentration (TPC) of DEAE12-CH-PEG-FA2/siRNA nanoparticles falls within the guidelines' thresholds: <1% hemolysis, 2.9% platelet aggregation, no complement activation, and no effect on coagulation times. ROS and NO production levels were comparable to controls. Cytokine secretion (TNF-α, IL-6, IL-4, and IL-10) was not affected by nanoparticles except for IL-1ß and IL-8. Nanoparticles showed a slight agglutination. Cell viability was >70% for TPC in all cell types, although LDH levels were statistically significant in Raw 264.7 macrophages and PBMC after 24 and 48 h of incubation. Conclusion: These DEAE12-CH-PEG-FA2/siRNA nanoparticles fulfill the existing ISO, ASTM and NCL guidelines' threshold criteria, and their low toxicity and blood biocompatibility warrant further investigation for potential clinical applications.


Assuntos
Quitosana/química , Terapia Genética , Nanopartículas/química , Polietilenoglicóis/química , Polímeros/química , Animais , Sobrevivência Celular/efeitos dos fármacos , Ácido Fólico/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Camundongos , Nanopartículas/administração & dosagem , Óxido Nítrico/metabolismo , Células RAW 264.7 , RNA Interferente Pequeno/genética , Espécies Reativas de Oxigênio/metabolismo , Testes de Toxicidade
4.
Ecotoxicol Environ Saf ; 202: 110932, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800216

RESUMO

Adverse health effects arising from exposure to fine particulates have become a major concern. Angiogenesis is a vital physiological process for the growth and development of cells and structures in the human body, whereby excessive or insufficient vessel growth could contribute to pathogenesis of diseases. We therefore evaluated indirect effects of carbon black (CB) and inhalable airborne particles on the angiogenic ability of unexposed Human Umbilical Vein Endothelial Cells (HUVECs) by co-culturing HUVECs with pre-exposed Small Airway Epithelial Cells (SAECs). As endothelial cells are major components of blood vessels and potential targets of fine particles, we investigated if lung epithelial cells exposed to ambient PM2.5 surrogates could induce bystander effects on neighboring unexposed endothelial cells in an alveolar-capillary co-culture lung model. Epithelial exposure to CB at a non-toxic dose of 25 µg/mL reduced endothelial tube formation and cell adhesion in co-cultured HUVECs, and decreased expression of angiogenic genes in SAECs. Similarly, exposure of differentiated SAECs to PM2.5 surrogates reduced cell reproductive ability, adhesion and tube formation of neighboring HUVECs. This indicates epithelial exposure to CB and urban PM2.5 surrogates both compromised the angiogenic ability of endothelial cells through bystander effects, thereby potentially perturbing the ventilation-perfusion ratio and affecting lung function.


Assuntos
Poluentes Atmosféricos/toxicidade , Material Particulado/toxicidade , Testes de Toxicidade , Técnicas de Cocultura , Células Epiteliais , Células Endoteliais da Veia Umbilical Humana/citologia , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Pulmão/metabolismo , Neovascularização Patológica , Fuligem
5.
Ecotoxicol Environ Saf ; 202: 110936, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800219

RESUMO

Developmental toxicity refers to the occurrence of adverse effects on a developing organism as a consequence of exposure to hazardous chemicals. The assessment of developmental toxicity has become relevant to the safety assessment process of chemicals. The zebrafish embryo developmental toxicology assay is an emerging test used to screen the teratogenic potential of chemicals and it is proposed as a promising test to replace teratogenic assays with animals. Supported by the increased availability of data from this test, the developmental toxicity assay with zebrafish has become an interesting endpoint for the in silico modelling. The purpose of this study was to build up quantitative structure-activity relationship (QSAR) models. In this work, new in silico models for the evaluation of developmental toxicity were built using a well-defined set of data from the ToxCastTM Phase I chemical library on the zebrafish embryo. Categorical and continuous QSAR models were built by gradient boosting machine learning and the Monte Carlo technique respectively, in accordance with Organization for Economic Co-operation and Development principles and their statistical quality was satisfactory. The classification model reached balanced accuracy 0.89 and Matthews correlation coefficient 0.77 on the test set. The regression model reached correlation coefficient R2 0.70 in external validation and leave-one-out cross-validated Q2 0.73 in internal validation.


Assuntos
Embrião não Mamífero/efeitos dos fármacos , Testes de Toxicidade/métodos , Poluentes Químicos da Água/toxicidade , Animais , Simulação por Computador , Substâncias Perigosas , Aprendizado de Máquina , Relação Quantitativa Estrutura-Atividade , Teratogênios , Peixe-Zebra/embriologia
6.
Ecotoxicol Environ Saf ; 202: 110911, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800246

RESUMO

Applications of TiO2 nanoparticles (NPs) in food, personal care products and industries pose risks on human health, particularly on vulnerable populations including pregnant women and infants. Fetus, deficient in mature defense system, is more susceptible to NPs. Publications on the developmental toxicity of TiO2 NPs on the maternal-exposed progeny have emerged. This review presents the main exposure routes of TiO2 NPs during pregnancy, including skin penetration, ingestion and inhalation, followed by transport of TiO2 NPs to the placenta. Accumulation of TiO2 NPs in placenta may cause dysfunction in nutrient transfer. TiO2 NPs can be even transported to the fetus and generate toxicities, such as impairments of nervous and reproductive system, and failure in lung and cardiovascular development. The toxicities rely on the crystalline phase and concentrations, and the main mechanisms include the accumulation of excessive reactive oxygen species, DNA damage, and over-activation of signaling pathways such as MAPK which impairs neurotransmission. Finally, this review remarks on the significance for identifying TiO2 NPs dosage safe for both mother and fetus, and particular attention should be paid at TiO2 NPs concentrations safe for mother but toxic to fetus. Importantly, research on the epigenetic trans-generational inheritance of TiO2 NPs is urgently needed to provide insights for deciding the prospects of TiO2 NPs applications.


Assuntos
Nanopartículas Metálicas/toxicidade , Titânio/toxicidade , Animais , Feminino , Feto , Humanos , Nanopartículas/toxicidade , Organogênese , Placenta/metabolismo , Gravidez , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Testes de Toxicidade
7.
Mar Pollut Bull ; 159: 111493, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32736201

RESUMO

The consumption of anticancer agents has increased in the recent decades, and these substances may be present in sewage. Consequently, they may reach the environment when sanitation infrastructure is ineffective. This study evaluated the toxicity of three anticancer agents-Tamoxifen (TAM), Cisplatin (CisPt), and Cyclophosphamide (CP)-on the development of embryos of the sand-dollar Mellita quinquiesperforata. Adult individuals were collected in sandy beaches, and gametes were obtained. Freshly-fertilized eggs were exposed to increasing sets of concentrations of each compound, and the effective concentrations needed to cause a 50% effect in the organisms (EC50) were calculated. The three compounds were toxic, and their EC50 values were 16.78 ± 2.42 ng·L-1 (TAM), 27.20 ± 38.26 ng·L-1 (CisPt), and 101.82 ± 70.96 ng·L-1 (CP). There is no information on the environmental levels of these compounds in Brazil, but as they were already detected in ng·L-1 levels worldwide, it can be expected that these substances pose environmental risks to the marine biota.


Assuntos
Antineoplásicos , Poluentes Químicos da Água/análise , Animais , Brasil , Ecotoxicologia , Ouriços-do-Mar , Testes de Toxicidade
8.
Ecotoxicol Environ Saf ; 202: 110959, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800231

RESUMO

Long-term field experiments were performed to evaluate the phytotoxic properties of fungal metabolites in oil-contaminated soil and to assess the impact of contamination on the allelopathic activity of soil mycobiota. Two contrasting soils of Northwest Russia (sandy and loamy podzols) exposed to oil contamination underwent changes in abundance and allelopathic activities of soil fungi. Shifts within the microbial community caused by oil contamination affected not only oil-decomposition rates but also ecotoxicity of contaminated soil. There were significant differences in soil toxicity dynamics between sandy and loamy podzols. Four years after contamination, ecotoxicity of loamy podzol decreased, whereas sandy podzol remained highly toxic even nine years after contamination. The abundance and allelopathic activity of fungi is correlated with hydrocarbon degradation dynamics. The soil fungal community demonstrated high allelopathic activity which decreased over time in fertile loamy podzolic soil, whereas in poor sandy podzolic soil it remained high over the nine-year monitoring period. The results illustrate how oil contamination may influence allelopathic interactions in soil and demonstrate the advantage of using fungal metabolite toxicity test for testing of oil-contaminated soil samples.


Assuntos
Fungos/efeitos dos fármacos , Hidrocarbonetos/toxicidade , Micotoxinas/toxicidade , Petróleo/toxicidade , Microbiologia do Solo , Poluentes do Solo/análise , Animais , Biodegradação Ambiental , Daphnia/efeitos dos fármacos , Daphnia/crescimento & desenvolvimento , Ecotoxicologia , Fungos/metabolismo , Hidrocarbonetos/análise , Micotoxinas/metabolismo , Petróleo/análise , Federação Russa , Solo/química , Testes de Toxicidade , Triticum/efeitos dos fármacos , Triticum/crescimento & desenvolvimento
9.
Zhonghua Yu Fang Yi Xue Za Zhi ; 54(7): 798-803, 2020 Jul 06.
Artigo em Chinês | MEDLINE | ID: mdl-32842306

RESUMO

With the increasing number of environmental chemicals, the risk assessment system based on animal toxicity testing is difficult to satisfy the current demands and needs to be reformed urgently. With the wide application of high-throughput screening technology, the advantage of exposomics in risk assessment is gradually emerging. Exposomics aims to study the health effects of mixed environmental exposure at different stages of life (especially in the early stage of life) through the dynamic monitoring of external and internal exposure levels. Exposomics is introduced into risk assessment to systematically study gene-environment interaction so as to provide a reliable basis for the construction of exposure-biomarker-disease network. This review summarized the importance and application prospect of exposomics in risk assessment of environmental chemicals in terms of the research progress, application in risk assessment and existing problems, opportunities and challenges.


Assuntos
Exposição Ambiental , Poluentes Ambientais/toxicidade , Animais , Biomarcadores , Monitoramento Ambiental , Medição de Risco , Testes de Toxicidade
10.
AAPS PharmSciTech ; 21(6): 230, 2020 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-32779033

RESUMO

The vaginal rings research is almost exclusively focused on rings for human medicine, although the dosage form offers improvement of therapeutic effect in other mammals as well. This contribution studied an effect of varying dimension parameters (diameter 20, 30 or 40 mm; height 3, 4 or 5 mm; width of annulus 5, 7.5 or 10 mm) on mechanical properties and dissolution behaviour of silicone vaginal rings with constant drug amount, intended for use in dogs. Results showed that altering dimensions influenced mechanical properties (compressive force, tensile strength and resistance of removal thread), in vitro drug release and water uptake. The removal thread resistance was increasing with increasing height and width. Compression force was higher for the rings with smaller diameter. The total drug release was increasing with decreasing height and rising diameter, surface area and water uptake during dissolution test. The initial dissolution rate was slower for the rings with higher width. As the best candidate for use in model dog subjects, the ring with 30 mm diameter, 3 mm height and 7.5 mm width was found. These drug-free vaginal rings were further tested in in vivo safety study. The results did not show any major deviation from the physiological conditions. Graphical abstract.


Assuntos
Dispositivos Anticoncepcionais Femininos , Animais , Cães , Liberação Controlada de Fármacos , Feminino , Fenômenos Mecânicos , Solubilidade , Resistência à Tração , Testes de Toxicidade
11.
Ecotoxicol Environ Saf ; 204: 111065, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32784014

RESUMO

In the present study, chemical analysis of contaminants (three classes of organic pollutants and seven metals) and elutriate toxicity test were adopted to evaluate the potential environmental hazards of dredged sediment samples from five sites (SS1-5) along Huangpu River Channel (Shanghai Harbor, China). The metal Pb, Cu, Cr, Zn and the organic pollutants including total hexachlorocyclohexane (HCHs) and total dichlorodiphenyltrichloroethane (DDTs) in the five samples exceeded the threshold for effects level (TEL) to varying degrees. The probable effect concentration quotients (QPECm) of contaminants from the five dredged samples were all above 0.25, which means potential toxicity risks. Elutriate toxicity tests using medaka fish (Oryzias melastigma) and manila clam (Ruditapes philippinarum) showed that SS2 caused mortality to both species and SS1 caused mortality to fish. To explore the molecular biomarkers that may reflect the toxic effects, differential expressed genes were identified by RNA-Seq-based transcriptome profiling from the survived clams exposed to the two polluted elutriates (SS1, SS2). In clams exposed to SS1 and SS2 elutriate, 368 and 860 differential expressed genes (DEGs) were up-regulated, 199 and 1304 genes were down-regulated, respectively. Fourteen DEGs were selected from the enriched pathways that reflect cytotoxicity and responses to xenobiotics for the following quantitative real time PCR analysis. The transcriptomic profiling and the selected gene's expression patterns from clams exposed to SS1 and SS2 showed significant differences with the non-contaminated and control groups. Using the expression data of the selected gene battery in Factor Analysis allowed the discrimination between contaminated and non-contaminated sites and may reflect an influence gradient of sites. The development of the assay of these molecular biomarkers may provide a rapid and high-throughput tool for the quality assessment of the dredging sediments.


Assuntos
Bivalves/efeitos dos fármacos , Monitoramento Ambiental/métodos , Expressão Gênica/efeitos dos fármacos , Sedimentos Geológicos/química , Rios/química , Poluentes Químicos da Água/toxicidade , Animais , Bivalves/genética , China , DDT/toxicidade , Hexaclorocicloexano/toxicidade , Metais Pesados/toxicidade , Testes de Toxicidade
12.
Ecotoxicol Environ Saf ; 204: 111111, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32795703

RESUMO

Bath treatment chemotherapeutants, used to control sea lice infestations in the salmonid aquaculture industry, are released directly into the marine environment around fish farms and pose a serious risk to non-target species, particularly crustaceans. Hydrogen peroxide (H2O2) is the most frequently used bath treatment chemotherapeutant on Norwegian fish farms, however, limited information is available on its toxicity to European lobsters (Homarus gammarus), a commercially important species at risk of exposure due to its distribution overlapping with salmon farm locations. The aim of this study was to investigate the lethal effects of H2O2 on pelagic (stage I-IV) larvae/post-larvae and its sub-lethal effects on the benthic stage V H. gammarus. To assess the lethal effects of H2O2, we carried out a series of 1 h toxicity tests and assessed mortality after a 24 h post-exposure period. Exposure to H2O2 was toxic to all pelagic larval stages tested, with estimated median lethal concentrations (LC50) of 177, 404, 665 and 737 mg/L for stage I, II, III and IV, respectively. These concentrations represent approximately 10, 23, 40 and 43%, of the recommended H2O2 concentrations used for delousing salmon on Norwegian fish farms, respectively. To assess the sub-lethal effects of H2O2 on H. gammarus, stage V juveniles were exposed to H2O2 at concentrations of 85, 170 and 510 mg/L for 1 h and shelter-seeking behaviour and mobility endpoints were assessed. Numerous behavioural parameters including distance travelled to shelter, time to locate shelter and the number of shelter inspections, were negatively affected in lobsters exposed to H2O2 when assessed immediately after the exposure period. However, no differences between control and exposed lobsters were detected after a 24 h post-exposure period. Our results demonstrate that short term exposures to H2O2 are lethal to pelagic H. gammarus life stages and can negatively affect the shelter seeking behaviour of benthic life stages, though these behavioural changes may be short-lived.


Assuntos
Peróxido de Hidrogênio/toxicidade , Nephropidae/fisiologia , Animais , Aquicultura/métodos , Comportamento Exploratório , Pesqueiros , Larva/efeitos dos fármacos , Dose Letal Mediana , Nephropidae/efeitos dos fármacos , Noruega , Salmão , Testes de Toxicidade
13.
Ecotoxicol Environ Saf ; 205: 111166, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32827966

RESUMO

N, N-Dimethylformamide (DMF) is a universal organic solvent which widely used in various industries, and a considerable amount of DMF is detected in industrial effluents. Accumulating animal and epidemiological studies have identified liver injury as an early toxic effect of DMF exposure; however, the detailed mechanisms remain poorly understood. In this study, we systematically integrated the quantitative proteomics, lipidomics, and metabolomics data obtained from the primary human hepatocytes exposed to DMF, to depict the complicated biochemical reactions correlated to liver damage. Eventually, we identified 284 deregulated proteins (221 downregulated and 63 upregulated) and 149 deregulated lipids or metabolites (99 downregulated and 50 upregulated) induced by DMF exposure. Further, the integration of the protein-metabolite (lipid) interactions revealed that N-glycan biosynthesis (involved in the endoplasmic reticulum stress and the unfolded protein response), bile acid metabolism (involved in the lipid metabolism and the inflammatory process), and mitochondrial dysfunction and glutathione depletion (both contributed to reactive oxygen species) were the typical biochemical reactions disturbed by DMF exposure. In summary, our study identified the versatile protein, lipid, and metabolite molecules in multiple signaling and metabolic pathways involved in DMF induced liver injury, and provided new insights to elucidate the toxic mechanisms of DMF.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Dimetilformamida/toxicidade , Poluentes Ambientais/toxicidade , Hepatócitos/efeitos dos fármacos , Metabolismo dos Lipídeos/efeitos dos fármacos , Metaboloma/efeitos dos fármacos , Proteoma/metabolismo , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Glutationa/metabolismo , Hepatócitos/metabolismo , Humanos , Lipidômica , Metabolômica , Cultura Primária de Células , Proteômica , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Testes de Toxicidade/métodos
14.
Int J Nanomedicine ; 15: 4091-4104, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32606666

RESUMO

Introduction: Humans are intentionally exposed to gold nanoparticles (AuNPs) where they are used in variety of biomedical applications as imaging and drug delivery agents as well as diagnostic and therapeutic agents currently in clinic and in a variety of upcoming clinical trials. Consequently, it is critical that we gain a better understanding of how physiochemical properties such as size, shape, and surface chemistry drive cellular uptake and AuNP toxicity in vivo. Understanding and being able to manipulate these physiochemical properties will allow for the production of safer and more efficacious use of AuNPs in biomedical applications. Methods and Materials: Here, AuNPs of three sizes, 5 nm, 10 nm, and 20 nm, were coated with a lipid bilayer composed of sodium oleate, hydrogenated phosphatidylcholine, and hexanethiol. To understand how the physical features of AuNPs influence uptake through cellular membranes, sum frequency generation (SFG) was utilized to assess the interactions of the AuNPs with a biomimetic lipid monolayer composed of a deuterated phospholipid 1.2-dipalmitoyl-d62-sn-glycero-3-phosphocholine (dDPPC). Results and Discussion: SFG measurements showed that 5 nm and 10 nm AuNPs are able to phase into the lipid monolayer with very little energetic cost, whereas, the 20 nm AuNPs warped the membrane conforming it to the curvature of hybrid lipid-coated AuNPs. Toxicity of the AuNPs were assessed in vivo to determine how AuNP curvature and uptake influence cell health. In contrast, in vivo toxicity tested in embryonic zebrafish showed rapid toxicity of the 5 nm AuNPs, with significant 24 hpf mortality occurring at concentrations ≥20 mg/L, whereas the 10 nm and 20 nm AuNPs showed no significant mortality throughout the five-day experiment. Conclusion: By combining information from membrane models using SFG spectroscopy with in vivo toxicity studies, a better mechanistic understanding of how nanoparticles (NPs) interact with membranes is developed to understand how the physiochemical features of AuNPs drive nanoparticle-membrane interactions, cellular uptake, and toxicity.


Assuntos
Membrana Celular/química , Ouro/toxicidade , Lipídeos/química , Membranas Artificiais , Nanopartículas Metálicas/toxicidade , Tamanho da Partícula , Testes de Toxicidade , Animais , Embrião não Mamífero/anormalidades , Embrião não Mamífero/efeitos dos fármacos , Humanos , Espectrofotometria Ultravioleta , Análise Espectral , Peixe-Zebra/embriologia
15.
Chemosphere ; 255: 127011, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32679630

RESUMO

The environmental toxicity of tetracycline antibiotics to aquatic organisms has attracted increasing attention. The adverse impacts of tetracycline antibiotics on ciliates should be detailed considering the significant roles of protozoa in the microfood web in the soils and other eco-systems. This study for the first time investigated the toxicity of two typical tetracycline antibiotics, tetracycline (TC) and tetracycline hydrochloride (HTC) on two primary model ciliates, Stentor coeruleus and Stylonychia lemnae. The concentrations for 50% of maximal effect (24h‒EC50) of TC and HTC to Stentor coeruleus were 94.4 mg/L and 8.39 mg/L, respectively. Correspondingly, the 24h‒EC50 values of TC and HTC to Stylonychia lemnae were 40.1 mg/L and 14.0 mg/L, respectively. The TC and HTC inhibited the growth rates, reduced the activities of antioxidant enzymes, and damaged the ultra-structures of the tested ciliate cells, with the latter having larger impacts than the former. Based on the experimental works reported herein, the two model protozoan species were proposed to be the toxicity indicators for tetracycline antibiotics, which could work as supplements with the other existing protocols, such as Brochydanio rerio (zebrafish), Limnodrilus (a worm), Chlorogonium elongatum (a green alga) also studied herein.


Assuntos
Antibacterianos/toxicidade , Cilióforos/efeitos dos fármacos , Tetraciclina/toxicidade , Antioxidantes/farmacologia , Tetraciclina/farmacologia , Testes de Toxicidade
16.
Bull Environ Contam Toxicol ; 105(2): 250-254, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32666193

RESUMO

Polychlorinated biphenyls (PCBs) are a class of persistent organic pollutants that pose a threat to environment and human health. Aiming at predicting PCBs risk in actual soil ecosystem, this study was conducted by chemical and biological methods to assess the bioavailability of PCBs in spiked soil, and in field-contaminated soils before or after remediation. The three chemical methods were Soxhlet, n-butanol and hydroxypropyl-ß-cyclodextrin (HPCD). Results were compared to actual PCB bioaccumulation in earthworms (Eisenia fetida). HPCD extraction was the best to predict the actual PCB bioaccumulation in all soils. The results suggest that HPCD could be an effective alternative method to earthworm toxicity test. This study provides strategy to understand the toxicity assessment in contaminated soil and soil after remediation.


Assuntos
Recuperação e Remediação Ambiental/métodos , Oligoquetos/efeitos dos fármacos , Bifenilos Policlorados/toxicidade , Poluentes do Solo/toxicidade , Solo/química , 1-Butanol/química , 2-Hidroxipropil-beta-Ciclodextrina/química , Animais , Bioacumulação , Disponibilidade Biológica , China , Ecossistema , Fertilizantes/análise , Oligoquetos/química , Bifenilos Policlorados/análise , Solo/normas , Poluentes do Solo/análise , Testes de Toxicidade
17.
Ecotoxicol Environ Saf ; 202: 110898, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32652344

RESUMO

Recent research has shown that the complexation of metals-organics plays an important role in atmospheric particulate matter, whose health effects should be taken into account. This work investigates the interactions between catechols (CAs), i.e., 4-nitrocatechol (4NC) and 4-methylcatechol (4MC), and transition metals (i.e., Fe) in the aqueous phase dark reaction. The formation of Fe/CAs complexes and secondary organics products are analyzed by UV-Vis spectroscopy, stopped-flow spectroscopy, high-resolution mass spectrometry and Raman spectroscopy, while the insoluble particulate matter formed from the CAs/Fe mixtures are characterized by the FTIR, X-ray photoelectron spectroscopy (XPS) and thermogravimetric-quadrupole-mass spectrometry (TG-Q-MS). On the basis of the density functional theory (DFT) calculation and experimental results, the possible formation pathways for the complexes of Fe(III) with 4NC (a proxy for organics) are proposed. The Fe/CAs complexes and organics products perhaps have significant sources of light absorption which play an important role in influencing the intensity of atmospheric radiation and particulate phase photochemistry. Besides, the cytotoxicity is tested as a function of concentrations for CAs/Fe mixtures in BEAS-2B cells. Our results show that CAs/Fe mixtures have strong association with cytotoxicity, indicating the mixtures have potential influence to human health.


Assuntos
Catecóis/química , Compostos Férricos/química , Testes de Toxicidade , Atmosfera/química , Catecóis/toxicidade , Células Epiteliais , Compostos Férricos/toxicidade , Humanos , Espectrometria de Massas , Metais , Material Particulado , Análise Espectral , Água/química
18.
Ecotoxicol Environ Saf ; 202: 110864, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32610224

RESUMO

An increasing amount of Fluoranthene (Fla) and Benz(a)anthracene (BaA) is being produced and used, eventually entering the soil sediments. The accumulation of Fla and BaA will cause poisoning to typical enzymes (α-Amylase) and organisms (Eisenia fetida) in soil. However, the studies about exploring and comparing the different effects of Fla, BaA and their joint effect at different levels are rarely reported. In this paper, the different effects of Fla, BaA and their mixed pollutant on α-Amylase were evaluated and compared at the molecular level, and the effect of Fla-BaA to the antioxidant system of earthworm (Eisenia fetida) was investigated from the aspects of concentration and exposure time at the animal level. The results showed that Fla-BaA had the greatest influence on the skeleton structure and the microenvironment of amino acid residue of α-Amylase compared to Fla and BaA, and in the mixed pollutant system, the joint effect mode was additive mode. The inhibitory effect of Fla-BaA on the activity of α-Amylase was also stronger than that of the system alone. The assays at the animal level showed that low concentrations (below 5 mg/kg) of Fla-BaA increased the activity of GSH-Px and SOD while high concentrations inhibited their activity. The POD that was activated throughout the experiment period suggested its key role in the earthworm antioxidant system. Changes in T-AOC and MDA showed that long-term and high-dose of Fla-BaA exposure inhibited the antioxidant capacity of Eisenia fetida, causing lipid peroxidation and damage to cells.


Assuntos
Benzo(a)Antracenos/toxicidade , Fluorenos/toxicidade , Poluentes do Solo/toxicidade , Animais , Antracenos , Antioxidantes/metabolismo , Poluentes Ambientais/metabolismo , Poluição Ambiental , Peroxidação de Lipídeos/efeitos dos fármacos , Oligoquetos/efeitos dos fármacos , Solo/química , Testes de Toxicidade
19.
Artigo em Inglês | MEDLINE | ID: mdl-32728873

RESUMO

Daphnia has been widely used as an indicator species in aquatic biomonitoring for decades. Traditional toxicity assays based on lethality take a long time to assess, and the effect mode of contaminants is not clear. Because of the translucency of the Daphnia body and the application of fluorescent probes in cell staining, different intoxicated parts can be visualized. In this study, a double-staining method using two fluorescent dyes, Calcein AM (cell-permeant dye) and Propidium Iodide (cell-impermeant dye), was carried out on Daphnia magna exposed to six pathogens: Salmonella spp. (four strains) and Shigella spp. (two strains). The results showed that those bacteria caused different infections on daphnia depending on the age of this organism and bacterial concentrations. In detail, S. dublin and S. sonnei are the most harmful to Daphnia when they cause damage at smaller concentrations at the younger stage (3 weeks old). Interestingly, older Daphnia can give responses to nearly 10 CFU/ml to less than 100 CFU/ml of some bacteria strains. In another experiment, S. sonnei disturbed Daphnia after just 10 min of exposure, and Daphnia adapted to S. choleraesuis, S. typhi, and S. flexneri at the early stage (3 weeks old) after 1 h of exposure. Moreover, the damaged areas of the daphnia body were directly observed via a microscope, contributing to the understanding and the prediction of toxicity mechanisms.


Assuntos
Daphnia/microbiologia , Salmonella/química , Shigella/química , Testes de Toxicidade/métodos , Animais , Corantes Fluorescentes/análise , Coloração e Rotulagem
20.
Environ Sci Pollut Res Int ; 27(32): 40604-40617, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32671701

RESUMO

A critical problem derived from airport operations is the environmental impact of runoff water. Airport runoff includes a complex mixture of pollutants, e.g., from deicing agents, that may affect negatively natural water bodies. This study assesses the spatial and temporal aquatic ecotoxicity of runoff water and possible aeroplane drift in a German airport. Over winter 2012-2013, from November to May, water samples were collected within the airport and surrounding area. These samples were analyzed using traditional physicochemical analysis and biotests with two aquatic organisms from different trophic levels, Lemna gibba and Aliivibrio fischeri. Overall, the samples examined in this study were relatively non-toxic to the tested organisms. The physicochemical parameters were mainly influenced by the sampling period being higher in colder months. In contrast, the ecotoxicity was influenced by the sampling site. For sites within the airport, a high correlation between the physicochemical parameters (EC and TOC) and toxicity in L. gibba was found. These correlations were not evident in samples taken outside the airport or when A. fischeri was used as a bioindicator. However, a pronounced seasonality has been observed, linked to the coldest months with average inhibition values of 50% in L. gibba and 25% in A. fischeri, particularly in January. Both biotests yielded differing results; therefore, more biotests should be included. However, L. gibba showed a good response with this type of water samples to be included in future studies together with detailed chemical analysis. The present study provides data to assess the potential ecotoxicological effects of airport runoff affected by winter operations.


Assuntos
Araceae , Poluentes Químicos da Água , Aeroportos , Aliivibrio fischeri , Bioensaio , Testes de Toxicidade , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
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