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1.
Ecotoxicol Environ Saf ; 215: 112151, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33743402

RESUMEN

The Water Framework Directive (WFD) was adopted in 2000 and is a common framework for water policy, management and protection in Europe. The WFD assesses specific parameters; however, it ignores indicators of ecosystem functioning and sub-individual performance. Reservoirs are strongly influenced by anthropogenic activities that promote their imbalance. Bioassays and biomarkers are useful tools to link the chemical, ecological and toxicological assessments in water quality assessments. These approaches can be complementary to WFD methodologies, allowing the detection of impacts on the ecosystem. This study evaluated if the biochemical parameters can improve the sensitivity of the biomonitoring strategy using bioassays with the standard species Daphnia magna, in the assessment of the ecological quality of water reservoirs. To this end, water samples of Portuguese reservoirs were analysed in three sampling periods (Autumn 2018 and Spring, Autumn 2019). In parallel, a physicochemical characterization of waters was performed. D. magna feeding rate assays were performed for 24 h. After exposure, metabolism, oxidative stress and lipid peroxidation biomarkers were evaluated. Feeding rate assays showed sensitivity to different reservoirs. Biomarkers showed a higher sensitivity and can therefore improve the sensitivity of the biomonitoring strategy using bioassays. Bioassays and biomarkers approach allowed to highlight potential sources of stress, more related to the quality of the seston than to chemical contamination. This work highlights the complementarity between bioassays and biomarkers to identify ecotoxicological effects of surface waters, and can be extremely useful, especially in cases where the biotic indices are difficult to establish, such as reservoirs.


Asunto(s)
Bioensayo , Monitoreo del Ambiente/métodos , Contaminantes Químicos del Agua/análisis , Animales , Monitoreo Biológico , Daphnia/efectos de los fármacos , Ecosistema , Ecotoxicología , Europa (Continente) , Estándares de Referencia , Estaciones del Año , Calidad del Agua
2.
SAR QSAR Environ Res ; 32(2): 151-174, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33525942

RESUMEN

One step towards reduced animal testing is the use of in silico screening methods to predict toxicity of chemicals, which requires high-quality data to develop models that are reliable and clearly interpretable. We compiled a large data set of fish early life stage no observed effect concentration endpoints (FELS NOEC) based on published data sources and internal studies, containing data for 338 molecules. Furthermore, we developed a new quantitative structure-activity-activity relationship (QSAAR) model to inform estimation of this endpoint using a combination of dimensionality reduction, regularization, and domain knowledge. In particular, we made use of a sparse partial least squares algorithm (sPLS) to select relevant variables from a huge number of molecular descriptors ranging from topological to quantum chemical properties. The final QSAAR model is of low complexity, consisting of 2 latent variables based on 8 molecular descriptors and experimental Daphnia magna acute data (EC50, 48 h). We provide a mechanistic interpretation of each model parameter. The model performs well, with a coefficient of determination r 2 of 0.723 on the training set (cross-validated q 2 = 0.686) and comparable predictivity on a test data set of chemically related molecules with experimental Daphnia magna data (r 2 test = 0.687, RMSE = 0.793 log units).


Asunto(s)
Daphnia/efectos de los fármacos , Peces/metabolismo , Larva/efectos de los fármacos , Relación Estructura-Actividad Cuantitativa , Pruebas de Toxicidad/veterinaria , Animales , Análisis de los Mínimos Cuadrados , Modelos Biológicos , Pruebas de Toxicidad/instrumentación
3.
SAR QSAR Environ Res ; 32(2): 133-150, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33601998

RESUMEN

A series of 18 2-arylidene indan-1,3-dione derivatives was synthesized and tested against Daphnia magna to assess the environmental toxicity of these compounds. Aiming to investigate the toxicity mechanism for this series of compounds, a four-dimensional quantitative structure-activity analysis (4D-QSAR) was performed through the partial least square regression (PLS). The best PLS model was built with two factors and the selected field descriptors, of Coulomb (C) and Lennard-Jones (L) nature, describing 77.43% of variance and presenting the following statistics: r 2 = 0.89; SEC = 0.30; Q 2 = 0.81; SEV = 0.36. According to the literature, the bioactivity of α,ß-unsaturated ketones, a functionality present in the series of compounds under investigation, is related to the conjugated double bond with the carbonyl group. The presence of a positive Coulomb descriptor nearby the carbonyl moieties, obtained as a result of the regression model, indicates that these polar groups are also related to the toxicity on D. magna. From the PLS regression model, the toxicity EC50-48 h values increases with the positive Coulomb descriptor and diminishes with the negative Lennard-Jones descriptors. It could be concluded that the presence of small polar groups in the aromatic ring of the arylidene moiety tends to increase the toxicity, while bulkier apolar substituents lead to a decrease of the toxicity.


Asunto(s)
Daphnia/efectos de los fármacos , Indanos/toxicidad , Relación Estructura-Actividad Cuantitativa , Contaminantes Químicos del Agua/toxicidad , Animales , Indanos/química , Contaminantes Químicos del Agua/química
4.
Ecotoxicol Environ Saf ; 212: 111967, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33524911

RESUMEN

Non-target effects of genetically engineered (GE) plants on aquatic Daphnia magna have been studied by feeding the species with different maize materials containing insecticidal Cry proteins from Bacillus thuringiensis (Bt). The results of those studies were often difficult to interpret, because only one GE plant was compared to one related non-GE control. In such a setting, effects of the Cry proteins cannot be distinguished from plant background effects, in particular when the test species is nutritionally stressed. In the present study, we tested the suitability of three different maize materials, i.e., flour, leaves and pollen, from five diverse non-GE maize lines (including EXP 258, a breeding line that is closely related to a SmartStax Bt maize) as exclusive food sources for D. magna. The parameters recorded included survival, sublethal endpoints such as body size, number of moltings to first offspring, time to first offspring, number of individuals in first clutch, total number of clutches, total number of offspring, average number of offspring per clutch, and population measures such as net reproductive rate R0, generation time T and intrinsic rate of increase rm. The results showed that D. magna can survive, grow and reproduce when fed only maize materials, although the performance was poorer than when fed algae, which indicates nutritional stress. Large differences in life table and population parameters of D. magna were observed among the different maize lines. Our results suggest that confounding effects caused by nutritional stress and plant background might explain some of the conflicting results previously published on the effects of Bt crops on D. magna. Using 95% confidence intervals for the means of the five maize lines for all measured parameters of D. magna performance in our study, we captured the natural range of variation. This information is useful for the interpretation of observed differences in D. magna performance between a GE plant and its non-GE comparator as it helps judging whether observed effects are of biological relevance. If differences between a GE and comparator line are observed and their biological relevance needs to be assessed in future risk assessments of GE maize, 1) the data on natural variation of the different parameters generated by previous studies can be informative (e.g. data from our study for maize fed D. magna); 2) for additional experiments the inclusion of multiple unrelated non-GE comparators should be considered; In addition, it should be taken into account that nutritional stress can affect the outcome of the study.


Asunto(s)
Daphnia/fisiología , Plantas Modificadas Genéticamente/fisiología , Zea mays/fisiología , Animales , Bacillus thuringiensis/metabolismo , Proteínas Bacterianas/metabolismo , Productos Agrícolas/metabolismo , Daphnia/efectos de los fármacos , Endotoxinas/metabolismo , Harina , Proteínas Hemolisinas/genética , Insecticidas/farmacología , Fitomejoramiento , Hojas de la Planta/metabolismo , Plantas Modificadas Genéticamente/metabolismo , Plantas Modificadas Genéticamente/toxicidad , Polen , Medición de Riesgo , Zea mays/metabolismo
5.
Arch Environ Contam Toxicol ; 80(2): 402-413, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33534037

RESUMEN

In this study, we assessed the effects of 11-day exposure of sulfadiazine (SD), sulfamethazine (SM2), norfloxacin (NOR), and enrofloxacin (ENR) on the growth, chlorophyll a (Chl. a) content, phycobiliproteins (PBPs) content, and alkaline phosphatase (ALP) activity of Chrysosporum ovalisporum, examined the removal rate of these antibiotics by C. ovalisporum, and performed acute toxicology test with Daphnia magna to determine the effect of interaction between antibiotics and cyanobacteria on aquatic animals. The results showed that the stress of SD and SM2 increased extracellular ALP activity and weakly inhibited the algal growth and the contents of Chl. a and PBPs compared with that noted in the control. ENR and NOR treatment groups exerted significant inhibition on algal growth as well as Chl. a and PBPs contents and ALP activity, although the cyanobacterium could degrade these two antibiotics more than SD and SM2. The results also revealed that the interaction between antibiotics and cyanobacteria could inhibit D. magna feeding.


Asunto(s)
Antibacterianos/metabolismo , Cianobacterias/metabolismo , Contaminantes Químicos del Agua/metabolismo , Animales , Clorofila A , Daphnia/efectos de los fármacos , Agua
6.
Ecotoxicol Environ Saf ; 208: 111677, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33396009

RESUMEN

CH3NH3PbI3 is one of the most widely studied and most promising photoelectric conversion materials for large-scale application. However, once it is discharged into the aquatic environment, it will release a variety of lethal substances to the aquatic organisms. Herein, two typical aquatic pollution indicators, Scenedesmus obliquus (a typical phytoplankton) and Daphnia magna (a typical zooplankton), were used to assess the acute effects of CH3NH3PbI3 perovskite on aquatic organisms. The results showed that, when the initial CH3NH3PbI3 perovskite level (CPL) was 40 mg L-1 or higher, the growth of S. obliquus would be remarkably inhibited with significant decreases of chlorophyll content and protein content. And when the CPL was over 5 mg L-1, the survival of D. magna would be notably threatened. Specifically, the 72 h EC-50 of CH3NH3PbI3 perovskite to S. obliquus was calculated as 37.21 mg L-1, and the 24 h LC-50 of this perovskite to D. magna adults and neonates were calculated as 37.53 mg L-1 and 18.55 mg L-1, respectively. Moreover, remarkably solution pH declination and large amounts of lead bio-accumulation was observed in the both acute experiments, which could be the main reasons causing the above acute effects. Considering the strong acute effects of these CH3NH3PbI3 perovskite materials and their attractive application prospect, more attentions should be paid on their harmness to the environment.


Asunto(s)
Compuestos de Calcio/toxicidad , Daphnia/efectos de los fármacos , Plomo/toxicidad , Metilaminas/toxicidad , Óxidos/toxicidad , Scenedesmus/efectos de los fármacos , Titanio/toxicidad , Contaminantes Químicos del Agua/toxicidad , Animales , Organismos Acuáticos/efectos de los fármacos , Compuestos de Calcio/química , Humanos , Plomo/química , Metilaminas/química , Óxidos/química , Propiedades de Superficie , Titanio/química , Pruebas de Toxicidad Aguda , Contaminantes Químicos del Agua/química
7.
Ecotoxicol Environ Saf ; 208: 111738, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33396066

RESUMEN

With an ever-increasing number of synthetic chemicals being manufactured, it is unrealistic to expect that they will all be subjected to comprehensive and effective risk assessment. A shift from conventional animal testing to computer-aided methods is therefore an important step towards advancing the environmental risk assessments of chemicals. The aims of this study are two-fold: firstly, it examines the relationships between structural and physicochemical features of a diverse set of organic chemicals, and their acute aquatic toxicity towards Daphnia magna and Oryzias latipes using a classification tree approach. Secondly, it compares the efficiency and accuracy of the predictions of two modeling schemes: local models that are inherently restricted to a smaller subset of structurally-related substances, and a global model that covers a wider chemical space and a number of modes of toxic action. The classification tree-based models differentiate the organic chemicals into either 'highly toxic' or 'low to non-toxic' classes, based on internal and external validation criteria. These mechanistically-driven models, which demonstrate good performance, reveal that the key factors driving acute aquatic toxicity are lipophilicity, electrophilic reactivity, molecular polarizability and size. A comparative analysis of the performance of the two modeling schemes indicates that the local models, trained on homogeneous data sets, are less error prone, and therefore superior to the global model. Although the global models showed worse performance metrics compared to the local ones, their applicability domain is much wider, thereby significantly increasing their usefulness in practical applications for regulatory purposes. This demonstrates their advantage over local models and shows they are an invaluable tool for modeling heterogeneous chemical data sets.


Asunto(s)
Pruebas de Toxicidad/métodos , Contaminantes Químicos del Agua/toxicidad , Animales , Daphnia/efectos de los fármacos , Compuestos Orgánicos/toxicidad , Relación Estructura-Actividad Cuantitativa , Medición de Riesgo
8.
Ecotoxicol Environ Saf ; 212: 111979, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33513482

RESUMEN

Silicon oxide (SiO2) nanostructures (SiO2NS) are increasingly being incorporated into an array of products, notably in the food, pharmaceutical, medical industries and in water treatment systems. Amorphous SiO2NS have low toxicity, however, due to their great versatility, superficial modifications can be made and these altered structures require toxicological investigation. In this study, SiO2NS were synthetized and amine-functionalized with the molecules (3-aminopropyl)triethoxysilane (APTMS) and 3-[2-(2-aminoethylamino)ethylamino]propyltrimethoxysilane (AEAEAPTMS), named SiO2NS@1 and SiO2NS@3, respectively. The bare SiO2NS, SiO2NS@1 and SiO2NS@3 samples were characterized and the influence of the culture medium used in the toxicological assays was also evaluated. The effect of amine functionalization of SiO2NS was investigated through acute and chronic toxicity assays with Daphnia magna. Modifications to ultrastructures of the intestine and eggs of these organisms were observed in TEM and SEM analysis. The toxicity was influenced by the surface modifications and a possible Trojan horse effect was highlighted, particularly in the case of chronic exposure. Exposure to all NSs promoted alterations in the microvilli and mitochondria of the D. magna intestine and some damage to egg cells was also observed. The results demonstrate the importance of carrying out a full characterization of these materials, since surface modifications can enhance their toxic potential.


Asunto(s)
Daphnia/fisiología , Nanoestructuras/toxicidad , Dióxido de Silicio/toxicidad , Aminas , Animales , Bioensayo , Daphnia/efectos de los fármacos , Pruebas de Toxicidad Aguda , Pruebas de Toxicidad Crónica , Contaminantes Químicos del Agua/toxicidad
9.
Chemosphere ; 262: 127823, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32777613

RESUMEN

We conducted the first complete toxicological study of six quinolones, including acute, chronic, and recovery assays on Daphnia magna and Ceriodaphnia dubia. The assayed quinolones were second-generation ciprofloxacin (CIP), norfloxacin (NOR), enrofloxacin (ENR), and marbofloxacin (MAR); third-generation levofloxacin (LEV), and fourth-generation moxifloxacin (MOX). The median lethal concentrations (LC50) obtained for both species by acute ecotoxicity assay ranged from 14 to 73 mg L-1 and from 3 to 23 mg L-1 at 48 and 72 h, respectively; while the median effective concentration (EC50) ranged from 4 to 28 mg L-1 in the chronic ecotoxicity assays. C. dubia surviving the chronic exposure assay was monitored in recovery assays free of quinolones. A fluorometric method was used to confirm that there was no significant loss of quinolone concentrations during the acute assays. We also used this method to show that quinolone concentrations fell below 80% of the nominal value after 9-11 d if exposure solutions were not renewed. This study on the ecotoxicological and chemical behavior of quinolones in two cladoceran species fills a data gap about how these emerging contaminants affect nontarget aquatic organisms and how long they persist in the environment.


Asunto(s)
Daphnia/fisiología , Quinolonas/toxicidad , Contaminantes Químicos del Agua/toxicidad , Animales , Bioensayo , Cladóceros/efectos de los fármacos , Daphnia/efectos de los fármacos
10.
Chemosphere ; 262: 128373, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33182143

RESUMEN

Since aquatic ecosystems receive runoff of most anthropogenic pollutants, risk assessment tools and protocols have been developed in order to protect them. However, most ecological risk assessments focus on the study of single species exposed to a single chemical, overlooking the environmental reality of multiple chemical exposures and stresses over generations. To advance in realistic predictions of population and community changes, the environmental disturbance history should be considered. The aim of this study was to evaluate how environmental disturbance history (continuous expected sublethal exposure to one chemical for several generations) determines populations' responses to another stressors. The experiments were performed with Daphnia magna as model organisms. To create a disturbance history, dimethoate was used as first stressor at two different concentrations: medium (0.089 mg·L-1) and high (0.89 mg·L-1). The population exposed to medium concentration ("vulnerable population") showed no differences from the control population in the selected parameters (body size and reproductive success). Our interest in the vulnerable population was to determine whether, after a first stressor, the detected non-effect hides a population impairment, which might undermine populations' responses to future stressors. After 4 generations under dimethoate exposure, the vulnerable D. magna population was exposed to a second chemical stressor (glyphosate) and an environmental stressor (food scarcity) as compared to control. The vulnerable population showed both less resistance to glyphosate and less resistance to starvation, corroborating the hypothesis that a disturbance history of continuous expected sublethal chemical exposures undermines populations' responses to further chemical and environmental stressors.


Asunto(s)
Contaminación Ambiental/estadística & datos numéricos , Animales , Daphnia/efectos de los fármacos , Ecosistema , Reproducción/efectos de los fármacos
11.
Ecotoxicol Environ Saf ; 207: 111274, 2021 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-32920315

RESUMEN

Nanomaterials (NMs) have significant technological advantages due to their unique properties but their release into the environment also carry potential eco-toxicological risks. Cu2O NMs have numerous industrial and commercial applications, however less is known about the risks to human health and ecosystems. This study investigated different shapes of nano-Cu2O (cubic and octahedron) with humic acid (HA: 2 mg/L and 10 mg/L) on the reproduction, growth, survival rate and Cu accumulation in the two-generations of Daphnia Magna species. Nano-Cu2O cubic and octahedron shapes were analyzed by SEM, demonstrating {111} and {100} facets. The results indicated that octahedron has the more evident toxic effect than cubic shape for both generations. Continuous exposure to nano-Cu2O exhibited negative effects on body length, cumulative neonates and Cu accumulation in filial generation F (1). Survival rate of Cu2O octahedron was the least 66%, while Cu2O cubic was 73% for parental generation F (0). In addition, HA showed a significant reduction in the toxicity of nano-Cu2O for both generations, leading to an enhanced survival rate, body length and reproduction. This study provides insights of the long-term effect of different shapes of nano-Cu2O in the existence of humic acid to the multi-generations ecosystem.


Asunto(s)
Daphnia/fisiología , Sustancias Húmicas , Contaminantes Químicos del Agua/toxicidad , Animales , Daphnia/efectos de los fármacos , Ecosistema , Nanoestructuras , Reproducción/efectos de los fármacos
12.
Aquat Toxicol ; 230: 105693, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33310671

RESUMEN

Sea dumping of chemical warfare (CW) took place worldwide during the 20th century. Submerged CW included metal bombs and casings that have been exposed for 50-100 years of corrosion and are now known to be leaking. Therefore, the arsenic-based chemical warfare agents (CWAs), pose a potential threat to the marine ecosystems. The aim of this research was to support a need for real-data measurements for accurate risk assessments and categorization of threats originating from submerged CWAs. This has been achieved by providing a broad insight into arsenic-based CWAs acute toxicity in aquatic ecosystems. Standard tests were performed to provide a solid foundation for acute aquatic toxicity threshold estimations of CWA: Lewisite, Adamsite, Clark I, phenyldichloroarsine (PDCA), CWA-related compounds: TPA, arsenic trichloride and four arsenic-based CWA degradation products. Despite their low solubility, during the 48 h exposure, all CWA caused highly negative effects on Daphnia magna. PDCA was very toxic with 48 h D. magna LC50 at 0.36 µg × L-1 and Lewisite with EC50 at 3.2 µg × L-1. Concentrations at which no immobilization effects were observed were slightly above the analytical Limits of Detection (LOD) and Quantification (LOQ). More water-soluble CWA degradation products showed no effects at concentrations up to 100 mg × L-1.


Asunto(s)
Arsénico/toxicidad , Sustancias para la Guerra Química/toxicidad , Daphnia/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidad , Animales , Arsénico/análisis , Arsenicales/análisis , Sustancias para la Guerra Química/análisis , Cloruros/análisis , Ecosistema , Dosificación Letal Mediana , Límite de Detección , Agua de Mar/química , Pruebas de Toxicidad Aguda , Contaminantes Químicos del Agua/análisis
13.
Int J Mol Sci ; 22(1)2020 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-33374973

RESUMEN

There is increasing recognition that environmental nano-biological interactions in model species, and the resulting effects on progeny, are of paramount importance for nanomaterial (NM) risk assessment. In this work, Daphnia magna F0 mothers were exposed to a range of silver and titanium dioxide NMs. The key biological life history traits (survival, growth and reproduction) of the F1 intergenerations, at the first (F1B1), third (F1B3) and fifth (F1B5) broods, were investigated. Furthermore, the F1 germlines of each of the three broods were investigated over 3 more generations (up to 25 days each) in continuous or removed-from NM exposure, to identify how the length of maternal exposure affects the resulting clonal broods. Our results show how daphnids respond to NM-induced stress, and how the maternal effects show trade-offs between growth, reproduction and survivorship. The F1B1 (and following germline) had the shortest F0 maternal exposure times to the NMs, and thus were the most sensitive showing reduced size and reproductive output. The F1B3 generation had a sub-chronic maternal exposure, whereas the F1B5 generation suffered chronic maternal exposure where (in most cases) the most compensatory adaptive effects were displayed in response to the prolonged NM exposure, including enhanced neonate output and reduced gene expression. Transgenerational responses of multiple germlines showed a direct link with maternal exposure time to 'sub-lethal' effect concentrations of NMs (identified from standard OECDs acute toxicity tests which chronically presented as lethal) including increased survival and production of males in the F1B3 and G1B5 germlines. This information may help to fine-tune environmental risk assessments of NMs and prediction of their impacts on environmental ecology.


Asunto(s)
Adaptación Fisiológica/efectos de los fármacos , Daphnia/efectos de los fármacos , Contaminantes Ambientales/toxicidad , Exposición Materna , Nanoestructuras/toxicidad , Animales , Daphnia/genética , Daphnia/fisiología , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Longevidad/efectos de los fármacos , Longevidad/genética , Nanoestructuras/química , Reproducción/efectos de los fármacos , Reproducción/genética , Factores de Tiempo , Titanio/química , Titanio/toxicidad
14.
Microbiome ; 8(1): 170, 2020 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-33339542

RESUMEN

BACKGROUND: Research around the weedkiller Roundup is among the most contentious of the twenty-first century. Scientists have provided inconclusive evidence that the weedkiller causes cancer and other life-threatening diseases, while industry-paid research reports that the weedkiller has no adverse effect on humans or animals. Much of the controversial evidence on Roundup is rooted in the approach used to determine safe use of chemicals, defined by outdated toxicity tests. We apply a system biology approach to the biomedical and ecological model species Daphnia to quantify the impact of glyphosate and of its commercial formula, Roundup, on fitness, genome-wide transcription and gut microbiota, taking full advantage of clonal reproduction in Daphnia. We then apply machine learning-based statistical analysis to identify and prioritize correlations between genome-wide transcriptional and microbiota changes. RESULTS: We demonstrate that chronic exposure to ecologically relevant concentrations of glyphosate and Roundup at the approved regulatory threshold for drinking water in the US induce embryonic developmental failure, induce significant DNA damage (genotoxicity), and interfere with signaling. Furthermore, chronic exposure to the weedkiller alters the gut microbiota functionality and composition interfering with carbon and fat metabolism, as well as homeostasis. Using the "Reactome," we identify conserved pathways across the Tree of Life, which are potential targets for Roundup in other species, including liver metabolism, inflammation pathways, and collagen degradation, responsible for the repair of wounds and tissue remodeling. CONCLUSIONS: Our results show that chronic exposure to concentrations of Roundup and glyphosate at the approved regulatory threshold for drinking water causes embryonic development failure and alteration of key metabolic functions via direct effect on the host molecular processes and indirect effect on the gut microbiota. The ecological model species Daphnia occupies a central position in the food web of aquatic ecosystems, being the preferred food of small vertebrates and invertebrates as well as a grazer of algae and bacteria. The impact of the weedkiller on this keystone species has cascading effects on aquatic food webs, affecting their ability to deliver critical ecosystem services. Video Abstract.


Asunto(s)
Daphnia/efectos de los fármacos , Desarrollo Embrionario/efectos de los fármacos , Microbioma Gastrointestinal/efectos de los fármacos , Glicina/análogos & derivados , Redes y Vías Metabólicas/efectos de los fármacos , Animales , Glicina/toxicidad
15.
Int J Nanomedicine ; 15: 8097-8108, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33116520

RESUMEN

Background: Metallic nanoparticles (NPs) are highly exploited in manufacturing and medical processes in a broad spectrum of industrial applications and in the academic sectors. Several studies have suggested that many metallic nanomaterials including those derived by silver (Ag) are entering the ecosystem to cause significant toxic consequences in cell culture and animal models. However, ecotoxicity studies are still receiving limited attention when designing functionalized and non.-functionalized AgNPs. Objective: This study aimed to investigate different ecotoxicological profiles of AgNPs, which were analyzed in two different states: in pristine form uncoated AgNPs and coated AgNPs with the antimicrobial peptide indolicidin. These two types of AgNPs are exploited for a set of different tests using Daphnia magna and Raphidocelis subcapitata, which are representatives of two different levels of the aquatic trophic chain, and seeds of Lepidium sativum, Cucumis sativus and Lactuca sativa. Results: Ecotoxicological studies showed that the most sensitive organism to AgNPs was crustacean D. magna, followed by R. subcapitata and plant seeds, while AgNPs coated with indolicidin (IndAgNPs) showed a dose-dependent decreased toxicity for all three. Conclusion: The obtained results demonstrate that high ecotoxicity induced by AgNPs is strongly dependent on the surface chemistry, thus the presence of the antimicrobial peptide. This finding opens new avenues to design and fabricate the next generation of metallic nanoparticles to ensure the biosafety and risk of using engineered nanoparticles in consumer products.


Asunto(s)
Péptidos Catiónicos Antimicrobianos/toxicidad , Organismos Acuáticos/efectos de los fármacos , Ecosistema , Ecotoxicología , Nanopartículas del Metal/toxicidad , Plata/toxicidad , Animales , Péptidos Catiónicos Antimicrobianos/síntesis química , Crustáceos/efectos de los fármacos , Cucumis sativus/efectos de los fármacos , Cucumis sativus/crecimiento & desarrollo , Daphnia/citología , Daphnia/efectos de los fármacos , Germinación/efectos de los fármacos , Lepidium/efectos de los fármacos , Lepidium/crecimiento & desarrollo , Lechuga/efectos de los fármacos , Lechuga/crecimiento & desarrollo , Nanopartículas del Metal/ultraestructura , Semillas/efectos de los fármacos , Semillas/crecimiento & desarrollo , Pruebas de Toxicidad
16.
Ecotoxicol Environ Saf ; 203: 111022, 2020 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-32888608

RESUMEN

To evaluate the aquatic hazards of the insect juvenile hormone analogue fenoxycarb, a single application (0, 48.8, 156.3, 500, 1600, and 5120 µg/L) of it was done in indoor freshwater systems dominated by Daphnia carinata (daphnid) and Dolerocypris sinensis (ostracoda). The responses of zooplankton (counted by abundance and the activity and immuno-reactive content of free N-Acetyl-ß-D-glucosaminidase (NAGase)), phytoplankton (counted by chlorophyll and phycocyanin), planktonic bacteria and fungi, and some water quality parameters were investigated in a period of 35 d. Results of the study showed that the ostracoda was more sensitive than daphnid, with time-weighted average (TWA)-based no observed effect concentrations (NOECs) to be 8.45 and 12.66 µg/L in systems without humic acid addition (HA-) and to be 6.37 and 9.54 µg/L in systems with humic acid addition (HA+). The duration of treatment-related effects in the ostracoda population was longer than the daphnid population (21 vs. 14 days). Besides, the data analysis indicated that the toxicity of fenoxycarb was significantly enhanced in the HA+ systems. Owing to the reduced grazing pressure, the concentrations of chlorophyll and phycocyanin increased in the two highest treatments. The increase in photosynthesis along with a reduced animal excretion led to an increase in pH and a decrease in nutrient contents. These changes seemed to have an effect on the microbial communities. For example, the abundances of some opportunistic pathogens of aquatic animals (e.g. Aeromonas and Cladosporium) and organic-pollutant-degrading microorganisms (e.g. Ancylobacter and Azospirillum) increased significantly in microbial communities, but the abundances of Pedobacter, Candidatus Planktoluna, and Rhodobacter (photosynthetic bacteria) markedly decreased. This study provides useful information to understand the ecotoxicological impacts of fenoxycarb at the population and community levels while integrating the effects of HA on toxicity.


Asunto(s)
Crustáceos/efectos de los fármacos , Daphnia/efectos de los fármacos , Agua Dulce/química , Fenilcarbamatos/toxicidad , Fitoplancton/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidad , Zooplancton/efectos de los fármacos , Animales , Ecotoxicología , Sustancias Húmicas/efectos adversos , Sustancias Húmicas/análisis , Microbiota/efectos de los fármacos
17.
Ecotoxicol Environ Saf ; 203: 111046, 2020 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-32888614

RESUMEN

Agricultural pesticides serve as effective controls of unwanted weeds and pests. However, these same chemicals can exert toxic effects in non-target organisms. To determine chemical modes of action, the toxicity ratio (TR) and critical body residues (CBRs) of 57 pesticides were calculated for Daphnia magna. Results showed that the CBR values of inert compounds were close to a constant while the CBR values of pesticides varied over a wider range. Although herbicides are categorized as specifically-acting compounds to plants, herbicides did not exhibit excess toxicity to Daphnia magna and were categorized as inert compounds with an average logTR = 0.41, which was less than a threshold of one. Conversely, fungicides and insecticides exhibited strong potential for toxic effects to Daphnia magna with an average logTR >2. Many of these chemicals act via disruption of the nervous, respiratory, or reproductive system, with high ligand-receptor binding activity which leads to higher toxicity for Daphnia magna. Molecular docking using acetylcholinesterase revealed that fungicides and insecticides bind more easily with the biological macromolecule when compared with inert compounds. Quantitative structure-activity relationship (QSAR) analysis revealed that the toxicity of fungicides was mainly dependent upon the heat of formation and polar surface area, while the toxicity of insecticides was more related to hydrogen-bond properties. This comprehensive analysis reveals that there are specific differences in toxic mechanisms between fungicides and insecticides. These results are useful for determining relative risk associated with pesticide exposure to aquatic crustaceans, such as Daphnia magna.


Asunto(s)
Daphnia/efectos de los fármacos , Modelos Biológicos , Plaguicidas/química , Plaguicidas/toxicidad , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/toxicidad , Acetilcolinesterasa/metabolismo , Animales , Daphnia/metabolismo , Relación Dosis-Respuesta a Droga , Fungicidas Industriales/química , Fungicidas Industriales/toxicidad , Herbicidas/química , Herbicidas/toxicidad , Enlace de Hidrógeno , Insecticidas/química , Insecticidas/toxicidad , Simulación del Acoplamiento Molecular , Residuos de Plaguicidas/metabolismo , Relación Estructura-Actividad Cuantitativa
18.
Ecotoxicol Environ Saf ; 205: 111291, 2020 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-32956865

RESUMEN

The purpose of this study was to determine the acute toxicity in aquatic organisms of one biocidal active substance and six metabolites derived from biocidal active substances and to assess the suitability of available QSAR models to predict the obtained values. We have reported the acute toxicity in sewage treatment plant (STP) microorganisms, in the freshwater microalgae Pseudokirchneriella subcapitata and in Daphnia magna following OECD test methods. We have also identified in silico models for acute toxicity of these trophic levels currently available in widely recognized platforms such as VEGA and the OECD QSAR ToolBox. A total of six, four and two models have been selected for Daphnia, algae and microorganisms, respectively. Finally, we have compared the in silico and in vivo data for the seven compounds plus two previously assayed biocidal substances. None of the compounds tested were toxic for Daphnia and STP microorganisms. For microalgae, CGA71019 (1,2,4 triazole) presented an ErC50 value of 38.3 mg/L. The selected in silico models have provided lower EC50 values and are therefore more conservative. Models from the OECD QSAR ToolBox predicted values for 7 out of 9 and for 4 out of 9 chemicals for Daphnia and P. subcapitata, respectively. No predictive models were identified in such platform for STP microorganism's acute effects. In terms of models's specificity, biocide-specific models, developed from curated datasets integrated by biocidal active substances and implemented in VEGA, perform better in the case of microalgae but for Daphnia an alternative, non biocide-specific has revealed a better performance. For STP microorganisms only biocide-specific models have been identified.


Asunto(s)
Organismos Acuáticos/efectos de los fármacos , Desinfectantes/toxicidad , Modelos Biológicos , Contaminantes Químicos del Agua/toxicidad , Animales , Chlorophyceae/efectos de los fármacos , Simulación por Computador , Daphnia/efectos de los fármacos , Desinfectantes/química , Desinfectantes/metabolismo , Agua Dulce/química , Microalgas/efectos de los fármacos , Relación Estructura-Actividad Cuantitativa , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/metabolismo
19.
Aquat Toxicol ; 227: 105595, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32911330

RESUMEN

In order to understand the potential impacts of nickel nanowires (Ni NWs) after reaching the aquatic environment, this research evaluated the toxicity of Ni NWs with different lengths (≤ 1.1, ≤11 and ≤ 80 µm) for several floating, planktonic and nektonic freshwater organisms. In this work, Ni NWs were synthesized by electrodeposition using anodized aluminum oxide (AAO) membranes. The toxicity of the NWs was assessed using a battery of aquatic species representative of key functions at the ecosystem level: the bacterium Aliivibrio fischeri, the algae Raphidocelis subcapitata, the macrophyte Lemna minor, the crustacean Daphnia magna and the zebrafish Danio rerio. Results indicated that for the concentrations tested (up to 2.5 mg L-1) the synthesized Ni NWs showed low toxicity. And although no lethal toxicity was observed for D. magna, at a sublethal level the feeding activity of the freshwater cladoceran was severely affected after exposure to Ni NWs. These findings showed that NWs can be accumulated in the gut of D. magna, even during a short exposure (24 h) directly impairing Daphnia nutrition and eventually populations growth. Consequently, this can also contribute to trophic transfer of NWs along the food chain. According to our results the toxicity of Ni NW may be mainly attributed to physical effects rather than chemical effects of Ni ions, considering that the concentrations of Ni NWs tested in this study were well below the toxicity thresholds reported in the literature for Ni ions and for Ni NMs.


Asunto(s)
Organismos Acuáticos/efectos de los fármacos , Nanocables/toxicidad , Níquel/toxicidad , Purificación del Agua/métodos , Aliivibrio fischeri , Animales , Chlorophyceae , Daphnia/efectos de los fármacos , Ecosistema , Cadena Alimentaria , Agua Dulce , Eliminación de Residuos Líquidos/métodos , Contaminantes Químicos del Agua/toxicidad , Pez Cebra
20.
Bull Environ Contam Toxicol ; 105(4): 530-537, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32940716

RESUMEN

An increase in the production and usage of gold nanoparticles (AuNPs) triggers the necessity to focus on their impact on ecosystems. Therefore, the purpose of this study was to investigate the acute toxicity of AuNPs and ionic gold (Au (III)) to organisms representing all trophic levels of the aquatic ecosystem, namely producers (duckweed Lemna minor), consumers (crustacean Daphnia magna, embryos of Danio rerio) and decomposers (bacteria Vibrio fischeri). The organisms were exposed according to a standardized protocol for each species and endpoints. The AuNPs (1.16 and 11.6 d.nm) were synthesized using citrate (CIT) and polyvinylpyrrolidone (PVP) as capping agents, respectively. It was found, that Au (III) was significantly more toxic than AuNPs PVP and AuNPs CIT. AuNPs showed significant toxicity only at high concentrations (mg/L), which are not environmentally relevant in the present time, but a cautious approach is advised, due to the possibility of interactions with other contaminants.


Asunto(s)
Aliivibrio fischeri/efectos de los fármacos , Araceae/efectos de los fármacos , Daphnia/efectos de los fármacos , Oro/toxicidad , Iones/toxicidad , Nanopartículas del Metal/toxicidad , Pez Cebra , Animales , Organismos Acuáticos , Daphnia/embriología , Relación Dosis-Respuesta a Droga , Embrión no Mamífero/efectos de los fármacos , Pruebas de Toxicidad Aguda
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