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1.
SAR QSAR Environ Res ; 31(10): 717-739, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32930630

RESUMO

Aedes aegypti is the primary vector of several infectious viruses that cause yellow, dengue, chikungunya, and Zika fevers. Recently, plant-derived products have been tested as safe and eco-friendly larvicides against Ae. aegypti. The present study aimed to improve QSAR models for 62 larvicidal phytocompounds against Ae. aegypti via the Monte Carlo method based on the index of the ideality of correlation (IIC) criterion. The representation of structures was done with SMILES. Three splits were prepared randomly and three QSAR models were constructed using IIC target function. The molecular descriptors were selected from SMILES descriptors and the hydrogen-filled molecular graphs. The predictability of three models was evaluated on the validation sets, the r 2 of which was 0.9770, 0.8660, and 0.8565 for models 1 to 3, respectively. The statistical results of three randomized splits indicated that robust, simple, predictive, and reliable models were obtained for different sets. From the modelling results, important descriptors were identified to enhance and reduce the larvicidal activity of compounds. Based on the identified important descriptors, some new structures of larvicidal compounds were proposed. The larvicidal activity of novel molecules designed further was supported by docking studies. Using the simple QSAR model, one can predict pLC50 of new similarity larvicidal phytocompounds.


Assuntos
Aedes/efeitos dos fármacos , Inseticidas/farmacologia , Mosquitos Vetores/efeitos dos fármacos , Relação Quantitativa Estrutura-Atividade , Aedes/crescimento & desenvolvimento , Animais , Inseticidas/química , Larva/efeitos dos fármacos , Mosquitos Vetores/crescimento & desenvolvimento
2.
Chemosphere ; 254: 126900, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957295

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous pollutants in marine environments and have arouse great concern since they pose adverse effects to marine ecosystem. To determine the potential impacts of environmentally relevant PAHs on early life stages of marine fish, this study exposed embryos of marine medaka (Oryzias melastigma) to 0, 2, 10, 50, and 250 µg/L of phenanthrene (Phe), one of the most abundant PAHs. The results demonstrated that Phe exposure decreased hatching rates, delayed hatching time of embryos, and increased deformity rate of newly-hatched larvae. Exposure to 10 and 50 µg/L Phe decreased the survival rate of marine medaka larvae at 28 days post-fertilization (dpf), and no embryo successfully hatched in 250 µg/L Phe exposure group. Morphology results showed that 10, 50, and 250 µg/L Phe exposure significantly retarded the development of embryos, and 2, 10, and 50 µg/L caused yolk sac edema and pericardial edema in newly-hatched larvae, indicating that low concentrations of Phe could induce developmental cardiac toxicity. Furthermore, the changes in the expression of heart development-related genes were determined, and the results showed that Phe-induced cardiac malformation might be related with fgf8, bmp4, smyd1, ATPase and gata4 genes. Overall, environmentally relevant PAHs could disrupt heart morphogenesis and hatching process of marine medaka, which might have profound consequences for sustainability of fish population.


Assuntos
Embrião não Mamífero/efeitos dos fármacos , Desenvolvimento Embrionário/efeitos dos fármacos , Oryzias/crescimento & desenvolvimento , Fenantrenos/toxicidade , Teratogênios/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Ecossistema , Embrião não Mamífero/anormalidades , Desenvolvimento Embrionário/genética , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Coração/efeitos dos fármacos , Coração/embriologia , Larva/efeitos dos fármacos , Larva/genética , Oryzias/genética , Fenantrenos/análise , Teratogênios/análise , Poluentes Químicos da Água/análise
3.
Nat Commun ; 11(1): 4608, 2020 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-32929085

RESUMO

Actinobacteria produce antibacterial and antifungal specialized metabolites. Many insects harbour actinobacteria on their bodies or in their nests and use these metabolites for protection. However, some actinobacteria produce metabolites that are toxic to insects and the evolutionary relevance of this toxicity is unknown. Here we explore chemical interactions between streptomycetes and the fruit fly Drosophila melanogaster. We find that many streptomycetes produce specialized metabolites that have potent larvicidal effects against the fly; larvae that ingest spores of these species die. The mechanism of toxicity is specific to the bacterium's chemical arsenal: cosmomycin D producing bacteria induce a cell death-like response in the larval digestive tract; avermectin producing bacteria induce paralysis. Furthermore, low concentrations of volatile terpenes like 2-methylisoborneol that are produced by streptomycetes attract fruit flies such that they preferentially deposit their eggs on contaminated food sources. The resulting larvae are killed during growth and development. The phenomenon of volatile-mediated attraction and specialized metabolite toxicity suggests that some streptomycetes pose an evolutionary risk to insects in nature.


Assuntos
Bactérias/metabolismo , Drosophila melanogaster/citologia , Drosophila melanogaster/microbiologia , Actinobacteria/fisiologia , Animais , Antraciclinas/farmacologia , Antibacterianos/química , Antibacterianos/farmacologia , Canfanos/toxicidade , Morte Celular/efeitos dos fármacos , Drosophila melanogaster/efeitos dos fármacos , Larva/efeitos dos fármacos , Larva/microbiologia , Metaboloma , Esporos Bacterianos/metabolismo , Esporos Bacterianos/fisiologia , Streptomyces/fisiologia , Análise de Sobrevida , Compostos Orgânicos Voláteis/farmacologia
4.
Ecotoxicol Environ Saf ; 203: 111043, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32888597

RESUMO

Intraspecific difference in toxicity brings uncertainty to ecological risk assessment (ERA) and water quality criteria (WQC) of chemicals. Here, we compared intraspecies sensitivity to toxicants for Mesocyclops leuckarti of which toxicity data was obtained from published literatures, and zebrafish Danio rerio of which toxicity data was done in this study). Due to the internal concentration of chemicals not measured, simplified toxicokinetic-toxicodynamic (TK-TD) models were used, and we investigated whether TK-TD parameters estimated by Bayesian method might represent the differences in sensitivity between life-stages of 2 species. The results demonstrated that the difference in TK-TD parameters (background mortality m0, no effect concentration NEC, the killing rate ks, and the dominant rate kd) could represent the toxicity difference between life-stages of individual species. The TK-TD model could predict toxicity in individual species (Cyprinus carpio L., Enchytraeus crypticus, Folsomia candida, Hyalella Azteca) exposed to different chemical concentrations and successfully extrapolate toxicity between different life stages of Mesocyclops leuckarti and Danio rerio by scaling several TK-TD parameters. The modified TK-TD model on the extrapolation toxicity of chemicals between life stages for species could be useful for the ERA and for deriving and revising WQC for chemicals.


Assuntos
Carpas/metabolismo , Copépodes/metabolismo , Embrião não Mamífero/efeitos dos fármacos , Larva/efeitos dos fármacos , Modelos Biológicos , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/metabolismo , Animais , Teorema de Bayes , Bioacumulação , Carpas/crescimento & desenvolvimento , Copépodes/crescimento & desenvolvimento , Embrião não Mamífero/metabolismo , Larva/metabolismo , Medição de Risco , Especificidade da Espécie , Toxicocinética , Peixe-Zebra/crescimento & desenvolvimento
5.
Ecotoxicol Environ Saf ; 203: 111033, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32888611

RESUMO

Diamide insecticides, such as chlorantraniliprole, cyantraniliprole, and tetrachlorantraniliprole, are a new class of insecticides that selectively target insects by affecting calcium homeostasis. While this class of insecticides are effective on a wide range of insect pests, the toxicities of diamide insecticides vary among species and life stages. In this study, we addressed the mechanism underlying the different responses of Plutella xylostella and Pieris rapae to diamide insecticides. The susceptibility to insecticides of P. xylostella and P. rapae larvae was assessed 2 and 4 days after exposure to chlorantraniliprole, cyantraniliprole, and tetrachlorantraniliprole. P. xylostella larvae treated with distilled water (Group A), chlorantraniliprole (Group B), cyantraniliprole (Group C), and tetrachlorantraniliprole (Group D) and P. rapae larvae treated with distilled water (Group E), chlorantraniliprole (Group F), cyantraniliprole (Group G) and tetrachlorantraniliprole (Group H) were subjected to metabolomics analysis. The differential metabolites in the B vs. F, C vs. G, and D vs. H groups were analyzed, followed by pathway enrichment analysis. Chlorantraniliprole, cyantraniliprole, and tetrachlorantraniliprole all showed high toxicities for P. xylostella and P. rapae larvae. P. rapae larvae were more sensitive to the diamide insecticides than P. xylostella larvae. There were 65 overlapped differential metabolites between P. xylostella and P. rapae larvae treated with these three diamide insecticides. Pathway analysis showed that the differential metabolites were closely related with fatty acid biosynthesis and metabolism-related pathways. The differential regulation of fatty acid biosynthesis and metabolism may contribute to the different response to diamide insecticides in P. xylostella and P. rapae.


Assuntos
Borboletas/efeitos dos fármacos , Diamida/farmacologia , Inseticidas/farmacologia , Metaboloma/efeitos dos fármacos , Mariposas/efeitos dos fármacos , Animais , Borboletas/metabolismo , Larva/efeitos dos fármacos , Larva/metabolismo , Mariposas/metabolismo , Especificidade da Espécie
6.
Chemosphere ; 254: 126792, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957266

RESUMO

Iron oxide nanoparticles (IONPs) are used in several medical and environmental applications, but their mechanism of action and hazardous effects to early developmental stages of fish remain unknown. Thus, the present study aimed to assess the developmental toxicity of citrate-functionalized IONPs (γ-Fe2O3 NPs), in comparison with its dissolved counterpart, in zebrafish (Danio rerio) after static and semi-static exposure. Embryos were exposed to environmental concentrations of both iron forms (0.3, 0.6, 1.25, 2.5, 5 and 10 mg L-1) during 144 h, jointly with negative control group. The interaction and distribution of both Fe forms on the external chorion and larvae surface were measured, following by multiple biomarker assessment (mortality, hatching rate, neurotoxicity, cardiotoxicity, morphological alterations and 12 morphometrics parameters). Results showed that IONPs were mainly accumulated on the zebrafish chorion, and in the digestive system and liver of the larvae. Although the IONPs induced low embryotoxicity compared to iron ions in both exposure conditions, these nanomaterials induced sublethal effects, mainly cardiotoxic effects (reduced heartbeat, blood accumulation in the heart and pericardial edema). The semi-static exposure to both iron forms induced high embryotoxicity compared to static exposure, indicating that the nanotoxicity to early developmental stages of fish depends on the exposure system. This is the first study concerning the role of the exposure condition on the developmental toxicity of IONPs on fish species.


Assuntos
Compostos Férricos/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Cloretos , Embrião não Mamífero/efeitos dos fármacos , Ferro/farmacologia , Larva/efeitos dos fármacos , Nanopartículas/toxicidade , Peixe-Zebra/embriologia
7.
Ecotoxicol Environ Saf ; 203: 110934, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32888599

RESUMO

Pharmaceuticals and personal care products are emerging contaminants that are increasingly detected in the environment worldwide. Certain classes of pharmaceuticals, such as selective serotonin reuptake inhibitors (SSRIs), are a major environmental concern due to their widespread use and the fact that these compounds are designed to have biological effects at low doses. A complication in predicting toxic effects of SSRIs in nontarget organisms is that their mechanism of action is not fully understood. To better understand the potential toxic effects of SSRIs, we employed an ultra-low input RNA-sequencing method to identify potential pathways that are affected by early exposure to two SSRIs (fluoxetine and paroxetine). We exposed wildtype zebrafish (Danio rerio) embryos to 100 µg/L of either fluoxetine or paroxetine for 6 days before extracting and sequencing mRNA from individual larval brains. Differential gene expression analysis identified 1550 genes that were significantly affected by SSRI exposure with a core set of 138 genes altered by both SSRIs. Weighted gene co-expression network analysis identified 7 modules of genes whose expression patterns were significantly correlated with SSRI exposure. Functional enrichment analysis of differentially expressed genes as well as network module genes repeatedly identified various terms associated with mitochondrial and neuronal structures, mitochondrial respiration, and neurodevelopmental processes. The enrichment of these terms indicates that toxic effects of SSRI exposure are likely caused by mitochondrial dysfunction and subsequent neurodevelopmental effects. To our knowledge, this is the first effort to study the tissue-specific transcriptomic effects of SSRIs in developing zebrafish, providing specific, high resolution molecular data regarding the sublethal effects of SSRI exposure.


Assuntos
Encéfalo/efeitos dos fármacos , Larva/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Inibidores de Captação de Serotonina/toxicidade , Transcriptoma/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Peixe-Zebra , Animais , Encéfalo/embriologia , Biologia Computacional , Embrião não Mamífero/efeitos dos fármacos , Desenvolvimento Embrionário/efeitos dos fármacos , Humanos , Larva/genética , Análise de Sequência de RNA , Peixe-Zebra/genética
8.
Ecotoxicol Environ Saf ; 202: 110906, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800241

RESUMO

The nonsteroidal anti-inflammatory drug diclofenac (DCF) is considered a contaminant of emerging concern. DCF can co-exist with heavy metals in aquatic environments, causing unexpected risks to aquatic organisms. This study aimed to assess the combined effects of DCF and cadmium (Cd) at environmentally relevant concentrations on the bioconcentration and status of oxidative stress and detoxification in Chironomus riparius larvae. The larvae were exposed to DCF (2 and 20 µg L-1) and Cd (5 and 50 µg L-1) alone or in mixtures for 48 h. The combined exposure to DCF and Cd was found to reciprocally facilitate the accumulation of each compound in larvae compared with single exposures. As indicated by the antioxidant enzyme activities, reduced glutathione levels, and malondialdehyde contents, the low concentration of the mixture (2 µg L-1 DCF + 5 µg L-1 Cd) did not alter the oxidative stress status in larvae, while the high concentration of the mixture (20 µg L-1 DCF + 50 µg L-1 Cd) induced stronger oxidative damage to larvae compared with single exposures. The expression levels of eight genes (CuZnSOD, MnSOD, CAT, GSTd3, GSTe1, GSTs4, CYP4G, and CYP9AT2) significantly decreased due to the high concentration of the mixture compared with single exposures in most cases. Overall, the results suggest that the mixture of DCF and Cd might exert greater ecological risks to aquatic insects compared with their individual compounds.


Assuntos
Cádmio/toxicidade , Chironomidae/fisiologia , Diclofenaco/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Cádmio/metabolismo , Chironomidae/efeitos dos fármacos , Diclofenaco/metabolismo , Inativação Metabólica/efeitos dos fármacos , Larva/efeitos dos fármacos , Malondialdeído/metabolismo , Metais Pesados/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Superóxido Dismutase/metabolismo , Poluentes Químicos da Água/metabolismo
9.
Ecotoxicol Environ Saf ; 202: 110909, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800244

RESUMO

The presence of mycotoxins in food has created concern. Mycotoxin prevalence in our environment has changed in the last few years maybe due to climatic and other environmental changes. Evidence has emerged from in vitro and in vivo models: some mycotoxins have been found to be potentially carcinogenic, embryogenically harmful, teratogenic, and to generate nephrotoxicity. The risk assessment of exposures to mycotoxins at early life stages became mandatory. In this regard, the effects of toxic compounds on zebrafish have been widely studied, and more recently, mycotoxins have been tested with respect to their effects on developmental and teratogenic effects in this model system, which offers several advantages as it is an inexpensive and an accessible vertebrate model to study developmental toxicity. External post-fertilization and quick maturation make it sensitive to environmental effects and facilitate the detection of endpoints such as morphological deformities, time of hatching, and behavioral responses. Therefore, there is a potential for larval zebrafish to provide new insights into the toxicological effects of mycotoxins. We provide an overview of recent mycotoxin toxicological research in zebrafish embryos and larvae, highlighting its usefulness to toxicology and discuss the strengths and limitations of this model system.


Assuntos
Micotoxinas/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra , Animais , Embrião não Mamífero/efeitos dos fármacos , Larva/efeitos dos fármacos , Teratogênios/toxicidade
10.
Pestic Biochem Physiol ; 169: 104668, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32828374

RESUMO

Diamondback moth (DBM), Plutella xylostella, is an important pest of crucifers worldwide. The extensive use of flubendiamide has led to the development of resistance in field populations and reports of control failures. In this study, the lab-selected (Rf) and field-collected (Rb) flubendiamide-resistant strains of P. xylostella with LC50 resistance ratios of 1890-fold and 1251-fold, respectively, were used, as well as a lab-reared flubendiamide-susceptible strain (S). The results showed that the fecundity of the Rf and Rb-resistant strains was significantly lower than that of S strain. The contents of vitellin and transcripts of P. xylostella vitellogenin (PxVg) and P. xylostella vitellogenin receptor (PxVgR) genes in the Rf and Rb strains were significantly higher than those of S strains at 0-48 h after adult eclosion. At 96 h after eclosion, the content of vitellin in the Rf and Rb strains did not differ significantly from those of S strains, whereas transcripts of the PxVg and PxVgR genes in the Rf and Rb strains were significantly lower than that of the S strain. The content of the juvenile hormone III (JH III), ß-ecdysone (20E), and the gene expression level of P. xylostella methoprene tolerant (PxMet) in the Rf and Rb strains were significantly higher than that of the S strain. The activity of trehalase was significantly higher in the Rf and Rb strains than that of the S strain in the first to the third instar larvae, whereas in the fourth instar larvae, there was no significantly difference in the three strains. At different times after adult eclosion, the differences in trehalase activity were erratic between the strains. The transcripts of P. xylostella trehalase (PxTre) gene in the Rf and Rb strains were significantly higher than that of the S strain in most developmental stages. Here, we report differences in fecundity between flubendiamide-resistant and susceptible strains of P. xylostella and discuss gene expression of several reproductive factors, which provides a possible explanation for the mechanism of fecundity reduction concurrent with flubendiamide-resistance in P. xylostella.


Assuntos
Inseticidas/farmacologia , Mariposas/efeitos dos fármacos , Animais , Benzamidas , Fertilidade/efeitos dos fármacos , Resistência a Inseticidas/efeitos dos fármacos , Larva/efeitos dos fármacos , Sulfonas
11.
PLoS One ; 15(8): e0236791, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32760094

RESUMO

In May 2010 the large white butterfly, Pieris brassicae L. (Lepidoptera: Pieridae), was discovered to have established in New Zealand. It is a Palearctic species that-due to its wide host plant range within the Brassicaceae-was regarded as a risk to New Zealand's native brassicas. New Zealand has 83 native species of Brassicaceae including 81 that are endemic, and many are threatened by both habitat loss and herbivory by other organisms. Initially a program was implemented to slow its spread, then an eradication attempt commenced in November 2012. The P. brassicae population was distributed over an area of approximately 100 km2 primarily in urban residential gardens. The eradication attempt involved promoting public engagement and reports of sightings, including offering a bounty for a two week period, systematically searching gardens for P. brassicae and its host plants, removing host plants, ground-based spraying of insecticide to kill eggs and larvae, searching for pupae, capturing adults with nets, and augmenting natural enemy populations. The attempt was supported by research that helped to progressively refine the eradication strategy and evaluate its performance. The last New Zealand detection of P. brassicae occurred on 16 December 2014, the eradication program ceased on 4 June 2016 and P. brassicae was officially declared eradicated from New Zealand on 22 November 2016, 6.5 years after it was first detected and 4 years after the eradication attempt commenced. This is the first species of butterfly ever to have been eradicated worldwide.


Assuntos
Brassicaceae/parasitologia , Borboletas/crescimento & desenvolvimento , Animais , Borboletas/fisiologia , Ecossistema , Herbivoria , Controle de Insetos , Inseticidas/toxicidade , Larva/efeitos dos fármacos , Larva/fisiologia , Nova Zelândia , Óvulo/efeitos dos fármacos , Vespas/fisiologia
12.
Ecotoxicol Environ Saf ; 204: 111068, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32745784

RESUMO

Herein, eight common endocrine disrupting chemicals (EDCs) were exposed to zebrafish (Danio rerio) to investigate the relationship between different EDCs and their activated estrogen receptors. Under acute exposure, we identified five major malformation types whose incidence and deformity modes differed among EDCs. Luciferase analysis divided the EDC receptors into four categories: (i) triclosan (TCS), 17ß-estradiol (E2) and estriol (E3) mainly activated GPER expression; (ii) bisphenol A (BPA), p-(tert-octyl) phenol (POP), 17α-ethynylestradiol (EE2), E2 and E3 activated ERß expression; (iii) E2 and E3 acted on both GPER and ERß; and (iv) estrone (E1) and 9,9-bis(4-hydroxyphenyl)fluorene (BHPF) had little effect on the two receptors. In vivo immunofluorescence experiments on 96-hpf larvae provided evidence that TCS and POP acted on GPER and ERß, respectively, while E2 acted on the two receptors simultaneously. Luciferase activities in the promoter regions of gper (-986 to -488) and erß (-1998 to -1496) were higher than those in other regions, identifying these key regions as targets for transcription activity. TCS promoted GPER expression by acting on the JUND transcription factor, while POP promoted ERß expression by activating the Foxl1 transcription factor. In contrast, E2 mainly regulated transcription of GPER and ERß by Arid3a. These findings provide compelling evidence that different EDCs possess varying estrogen receptors, leading to differential regulatory pathways and abnormality symptoms. These results offer an experimental strategy and fundamental information to assess the molecular mechanisms of EDC-induced estrogen effects.


Assuntos
Compostos Benzidrílicos/toxicidade , Disruptores Endócrinos/toxicidade , Receptor beta de Estrogênio/metabolismo , Fenóis/toxicidade , Receptores Acoplados a Proteínas-G/metabolismo , Poluentes Químicos da Água/toxicidade , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/metabolismo , Animais , Compostos Benzidrílicos/metabolismo , Embrião não Mamífero/efeitos dos fármacos , Embrião não Mamífero/metabolismo , Desenvolvimento Embrionário/efeitos dos fármacos , Disruptores Endócrinos/metabolismo , Larva/efeitos dos fármacos , Larva/metabolismo , Fenóis/metabolismo , Poluentes Químicos da Água/metabolismo
13.
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
14.
PLoS One ; 15(8): e0237876, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32817683

RESUMO

To explain the asymmetrical abundance of native Frankliniella intonsa (Trybom) (Thysanoptera: Thripidae) and invasive Frankliniella occidentalis (Pergande) in the fields, we examined differential susceptibility to pesticides and environmental conditions, i.e., nine combinations of temperatures and relative humidities (RHs). We found adult female F. intonsa to be more susceptible to most of the tested insecticides as compared to F. occidentalis. Chlorfenapyr was most toxic to both thrips' species. In the evaluation of environment conditions in the adult stage, F. intonsa survived 2.5 and 2.4-fold longer as RH increased at 20 and 25 °C, respectively, whereas F. occidentalis survived 1.8 and 1.6-fold longer, respectively. In both pupal and larval stage, no significant effect of interaction of temperatures and RHs was found between the two species. In conclusion, the insecticides tested differed considerably in their species-specific toxicity, and F. intonsa was generally more susceptible to the insecticides, while at the same time survivorship was better at higher RH conditions than F. occidentalis. Thus, differences in the relative susceptibility to changing environmental conditions, especially humidity, may be an underlying mechanism for the recent dominance of F. intonsa over F. occidentalis in the strawberry plastic greenhouse in Korea.


Assuntos
Inseticidas/toxicidade , Praguicidas/toxicidade , Piretrinas/toxicidade , Tisanópteros/efeitos dos fármacos , Animais , Feminino , Fragaria/parasitologia , Umidade , Espécies Introduzidas , Larva/efeitos dos fármacos , Pupa/efeitos dos fármacos , República da Coreia , Especificidade da Espécie , Temperatura
15.
Aquat Toxicol ; 227: 105593, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32861021

RESUMO

Along with traditional ecotoxicological approaches in model organisms, toxicological studies in non-model organisms are being taken into consideration in order to complement them and contribute to more robust approaches. This allows us to figure out the complexity of the exposures involved in natural ecosystems. In this context, in the present research we have used the model species Chironomus riparius (Chironomidae, Diptera) and the non-model species Prodiamesa olivacea (Chironomidae, Diptera) to assess the aquatic toxic effects of acute 4-h and 24-h exposures to 1 µgL-1 of three common environmental pollutants: butyl benzyl phthalate (BBP), bisphenol A (BPA), and benzophenone 3 (BP3). Individuals of both species were collected from a contaminated river (Sar) in Galicia (Spain). Regarding Chironomus, there are four OECD standardized tests for the evaluation of water and sediment toxicity, in which different species in this genus can be used to assess classical toxicity parameters such as survival, immobilization, reproduction, and development. In contrast, Prodiamesa is rarely used in toxicity studies, even though it is an interesting toxicological species because it shares habitats with Chironomus but requires less extreme conditions (e.g., contamination) and higher oxygen levels. These different requirements are particularly interesting in assessing the different responses of both species to pollutant exposure. Quantitative real-time PCR was used to evaluate the transcriptional changes caused by xenobiotics in different genes of interest. Since information about P. olivacea in genomic databases is scarce, its transcriptome was obtained using de novo RNAseq. Genes involved in biotransformation pathways and the oxidative stress response (MnSOD, CAT, PHGPx, Cyp4g15, Cyp6a14-like and Cyp6a2-like) were de novo identified in this species. Our results show differential toxic responses depending on the species and the xenobiotic, being P. olivacea the dipteran that showed the most severe effects in most of the studied biomarker genes. This work represents a multi-species approach that allows us to deepen in the toxicity of BBP, BPA, and BP3 at the molecular level. Besides, it provides an assessment of the tolerance/sensitivity of natural populations of model and non-model insect species chronically exposed to complex mixtures of pollutants in natural scenarios. These findings may have important implications for understanding the adverse biological effects of xenobiotics on P. olivacea, providing new sensitive biomarkers of exposure to BBP, BPA, and BP3. It also highlights the suitability of Prodiamesa for ecotoxicological risk assessment, especially in aquatic ecosystems.


Assuntos
Biomarcadores/metabolismo , Chironomidae/fisiologia , Biomarcadores Ambientais , Poluentes Químicos da Água/toxicidade , Animais , Compostos Benzidrílicos , Benzofenonas , Chironomidae/efeitos dos fármacos , Ecossistema , Larva/efeitos dos fármacos , Fenóis , Ácidos Ftálicos , Rios , Espécies Sentinelas , Xenobióticos/metabolismo
16.
Aquat Toxicol ; 227: 105607, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32861022

RESUMO

The ubiquitous contamination of environmental lead (Pb) remains a worldwide threat. Improper Pb mine waste disposal from an abandoned lead-zinc mine has recently unearthed widespread Pb poisoning in children in Kabwe Zambia. Although the adverse effects of Pb on human health have begun to receive attention, the ecotoxicological effects on aquatic vertebrates still need further investigation. In addition, there is paucity in the knowledge on the behavioural and molecular subcellular responses in larval zebrafish exposed to Pb within the range of environmental relevant concentration (average 3 µg/L with maximum of 94 µg/L) on aquatic organisms such as zebrafish. The adverse effects of environmentally relevant levels of Pb on larval zebrafish was evaluated by measuring swimming behaviour under alternating dark and light conditions. Larval zebrafish acutely exposed to environmentally relevant Pb exhibited neuro-behavioural alteration including enhanced hyperactivity under light conditions evidenced by increased distanced covered and speed compared to the control. The alteration of entire behavioral profiles was further associated with the disturbed expression patterns of mRNA level of key genes associated with antioxidant (HO-1, Ucp-2 and CoxI), proapoptotic gene (TP53), and antiapoptotic gene (Bcl-2). To our knowledge, this is the first report on the effects of environmentally relevant Pb levels from Kabwe, Zambia and their adverse neurobehavioural effects and subcellular molecular oxidative responses in larval zebrafish acutely exposed within a 30 min period. The current results would be beneficial in our understanding of the effects of low Pb levels acutely discharged into an aquatic environment and the life of aquatic organisms.


Assuntos
Chumbo/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/fisiologia , Animais , Antioxidantes/metabolismo , Apoptose/efeitos dos fármacos , Humanos , Larva/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Testes de Toxicidade Aguda
17.
Hear Res ; 395: 108019, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32768772

RESUMO

Hearing and balance deficits have been reported during and following treatment with the antimalarial drug chloroquine. However, experimental work examining the direct actions of chloroquine on mechanoreceptive hair cells in common experimental models is lacking. This study examines the effects of chloroquine on hair cells using two common experimental models: the zebrafish lateral line and neonatal mouse cochlear cultures. Zebrafish larvae were exposed to varying concentrations of chloroquine phosphate or hydroxychloroquine for 1 h or 24 h, and hair cells assessed by antibody staining. A significant, dose-dependent reduction in the number of surviving hair cells was seen across conditions for both exposure periods. Hydroxychloroquine showed similar toxicity. In mouse cochlear cultures, chloroquine damage was specific to outer hair cells in tissue from the cochlear basal turn, consistent with susceptibility to other ototoxic agents. These findings suggest a need for future studies employing hearing and balance monitoring during exposure to chloroquine and related compounds, particularly with interest in these compounds as therapeutics against viral infections including coronavirus.


Assuntos
Sobrevivência Celular/efeitos dos fármacos , Cloroquina/análogos & derivados , Células Ciliadas Auditivas/efeitos dos fármacos , Hidroxicloroquina/toxicidade , Sistema da Linha Lateral/efeitos dos fármacos , Animais , Antivirais/toxicidade , Células Cultivadas , Cloroquina/toxicidade , Células Ciliadas Auditivas/citologia , Larva/efeitos dos fármacos , Camundongos , Modelos Animais , Ototoxicidade , Peixe-Zebra
18.
Bull Environ Contam Toxicol ; 105(3): 387-392, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32757041

RESUMO

Systematic studies on the impact of environmental pollution on the survival adaptability of amphibians are relatively few. In this study, Bufo raddei tadpoles from two places with totally different backgrounds of heavy metal pollution were chosen to explore the effects of heavy metal pollution on fitness and swimming performance of tadpoles, the physiological effects were investigated as well. The tadpoles at GS 25, GS 30 and GS 35 were collected randomly from the two study sites and were exposed to different environmental temperatures. The results showed that heavy metal enrichment and antioxidant levels were significantly higher in the tadpoles under long-term heavy metal stress. Meanwhile, heavy metal pollution affected the adaptability of tadpoles to environmental change and decreased the swimming performance of the tadpoles. Unexpected, the tadpoles from heavy metal-polluted area also showed some adaptive changes, mainly reflected in the increase in swimming endurance.


Assuntos
Larva/fisiologia , Metais Pesados/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Bufonidae , Poluentes Ambientais , Poluição Ambiental , Larva/efeitos dos fármacos , Metais Pesados/análise , Natação
19.
Ecotoxicol Environ Saf ; 204: 111052, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32739675

RESUMO

Transgenerational effects on sensitivity to pesticides are poorly studied. This study investigated the transgenerational influences of maternal body mass in the major pest moth Spodoptera littoralis, with a focus on sensitivity to chlorpyrifos pesticide. In 147 clutches of a laboratory strain of S. littoralis, we compared larval mortality between control larvae and larvae treated with chlorpyrifos. Because of the classic positive relationships between offspring size and maternal size and between offspring size and offspring quality, sensitivity to chlorpyrifos was predicted to be lower in larvae of larger mothers. Surprisingly, we found the opposite result, with higher pesticide toxicity in larvae of larger mothers. This result is partly explained by the lack of a relationship between larval mass and larval sensitivity to chlorpyrifos. This means that another offspring characteristic linked to maternal size should have affected larval sensitivity to chlorpyrifos. More generally, knowledge of the effects of the traits and ecological environments of mothers on offspring sensitivity to pesticides remains limited. Ecotoxicologists should pay more attention to such maternal effects on sensitivity to pesticides, both in pests and non-target species.


Assuntos
Clorpirifos/toxicidade , Epigênese Genética , Resistência a Inseticidas/genética , Inseticidas/toxicidade , Spodoptera/efeitos dos fármacos , Animais , Peso Corporal/efeitos dos fármacos , Feminino , Larva/efeitos dos fármacos , Larva/genética , Larva/crescimento & desenvolvimento , Longevidade/efeitos dos fármacos , Exposição Materna , Spodoptera/genética , Spodoptera/crescimento & desenvolvimento
20.
Ecotoxicol Environ Saf ; 204: 111034, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32758695

RESUMO

Trehalose is the major blood sugar in insects; it not only serves as an energy source but also plays important roles in physiological responses to adverse conditions. However, only a few studies have explored the effects of heavy metal exposure stress on trehalose metabolism in insects. Therefore, in this study, we examined the effects of cadmium stress on changes in trehalose metabolism in Aedes albopictus. Three concentrations of cadmium (0.005, 0.01, and 0.1 mg/L) were selected for evaluation of long-term stress in Ae. albopictus (from eggs to adults); Ae. albopictus in double-distilled water was used as the control group. The trehalose and glucose contents, trehalase activity, and trehalose metabolism-related gene expression were determined. The effects of long-term cadmium exposure on growth, development, and reproduction were also assessed. Trehalose contents were increased, whereas glucose contents and trehalase activity were decreased in Ae. albopictus following long-term exposure to low concentrations of cadmium compared with those in untreated individuals. Moreover, the expression of trehalose-6-phosphate synthase was upregulated, and that of trehalase was downregulated, indicating that Ae. albopictus may enhance trehalose synthesis to resist cadmium stress. Cadmium exposure also caused Ae. albopictus individuals to become smaller with a longer developmental duration, whereas both reproduction and hatching rates of the offspring were decreased compared with those in the control group. Our findings demonstrated that cadmium exposure affected the morphology, physiology, and biochemistry of Ae. albopictus. These findings also confirmed the role of trehalose in the response of Ae. albopictus to cadmium stress, providing insights into the effects of heavy metal stress on trehalose metabolism in an insect model.


Assuntos
Aedes/efeitos dos fármacos , Cádmio/efeitos adversos , Trealose/metabolismo , Poluentes Químicos da Água/efeitos adversos , Aedes/crescimento & desenvolvimento , Aedes/metabolismo , Animais , Feminino , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Larva/metabolismo , Óvulo/efeitos dos fármacos , Óvulo/crescimento & desenvolvimento , Óvulo/metabolismo , Pupa/efeitos dos fármacos , Pupa/crescimento & desenvolvimento , Pupa/metabolismo
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