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1.
J Agric Food Chem ; 67(41): 11536-11541, 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31589045

RESUMO

Limited reports on the use of nanobodies (Nbs) in fluorescence polarization immunoassay (FPIA) aroused us to explore if the small size of Nbs is a drawback for the development of sensitive FPIA to small molecular compounds, particularly since FPIA is a technology strongly dependent on molecular weight. In the present work, three different molecular weight Nbs against 3-phenoxybenzoic acid (3-PBA), an exposure biomarker of pyrethroid insecticides, including bare Nbs (15 kDa), Nbs-Avidin (Nbs-AV, 60 kDa), and Nbs-Alkaline phosphatase (Nbs-AP, 130 kDa) were specifically generated to cover distinct regions on the polarization and molecular weight relationship curve for a fluorescein tracer. In competitive FPIA, similar half-maximal inhibitory concentrations (IC50) of 3-PBA of 16.4, 12.2, and 14.8 ng mL-1 were obtained for Nbs, Nbs-AV, and Nbs-AP, respectively, indicating that the size of Nbs in the range tested had no significant effect on the sensitivity of the resulting competitive FPIA. An IC50 of 20.2 ng mL-1 for an anti-3-PBA polyconal antibody based FPIA further demonstrated the performance of Nbs, which was comparable to that of traditional antibodies in FPIA. Spike-recovery studies showed good and reproducible recovery of 3-PBA in urine samples, demonstrating the applicability of Nb-based FPIA. Overall, our results show that Nb-based FPIA achieves sensitivity levels of FPIA based on conventional antibodies and further indicate that Nb absolutely meets the sensitivity requirement of FPIA.


Assuntos
Benzoatos/urina , Imunoensaio de Fluorescência por Polarização/métodos , Inseticidas/toxicidade , Piretrinas/toxicidade , Anticorpos de Domínio Único/química , Biomarcadores/urina , Exposição Ambiental/análise , Imunoensaio de Fluorescência por Polarização/instrumentação , Humanos , Inseticidas/análise , Piretrinas/análise , Sensibilidade e Especificidade
2.
J Agric Food Chem ; 67(40): 10997-11004, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31487170

RESUMO

The enantioselective bioactivity, toxicity, and environmental behaviors of isocarbophos (ICP) were investigated. The order of the bioactivity and toxicity was S-(+) ≥ rac > R-(-), and the difference of R-(-) and S-(+) was up to 232 times. The usage of S-(+)-ICP may efficiently reduce the usage amount of rac-ICP by 35% under the same effect, and the toxicity was not increased. Based on the toxic unit analysis, the additive effect and synergistic effect of ICP enantiomers were found in the four nontarget organisms, and R-(-)-ICP might cooperate the side-effects of S-(+)-ICP. The accumulation of rac-ICP in earthworms was enantioselective with an enantioenrichment of R-(-)-ICP, so the usage of racemic ICP might increase the exposure risk of R-(-)-ICP to earthworms. From the comprehensive results, the production of enantiomer enriched S-(+)-ICP might increase bioactivity and reduce environmental pollution, while the toxicity of S-(+)-ICP to other nontarget organisms needs to be further assessed.


Assuntos
Inseticidas/química , Inseticidas/toxicidade , Malation/análogos & derivados , Animais , Malation/química , Malation/toxicidade , Oligoquetos/efeitos dos fármacos , Oligoquetos/crescimento & desenvolvimento , Estereoisomerismo , Relação Estrutura-Atividade
3.
Sci Total Environ ; 690: 1237-1244, 2019 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-31470486

RESUMO

To improve risk assessment there is increasing attention for the effect of climate change on the sensitivity to contaminants and vice versa. Two important and connected topics have been largely ignored in this context: (i) the increase of daily temperature variation (DTV) as a key component of climate change, and (ii) differences in sensitivity to climate change and contaminants between developmental stages. We therefore investigated whether DTV magnified the negative effects of the organophosphate insecticide chlorpyrifos on mortality and heat tolerance and whether this effect was stronger in aquatic larvae than in terrestrial adults of the mosquito Culex pipiens. Exposure to chlorpyrifos at a constant temperature imposed mortality and reduced the heat tolerance in both larvae and adult males, but not in adult females. This provides the first evidence that the TICS ("toxicant-induced climate change sensitivity") concept can be sex-specific. DTV had no direct negative effects. Yet, consistent with the CITS ("climate-induced toxicant sensitivity") concept, DTV magnified the toxicity of the pesticide in terms of larval mortality. This was not the case in the adult stage indicating the CITS concept to be dependent on the developmental stage. Notably, chlorpyrifos reduced the heat tolerance of adult females only in the presence of DTV, thereby providing support for the reciprocal effects between DTV and contaminants, hence the coupling of the TICS and CITS concepts. Taken together, our results highlight the importance of integrating DTV and the developmental stage to improve risk assessment of contaminants under climate change.


Assuntos
Clorpirifos/toxicidade , Culicidae/fisiologia , Inseticidas/toxicidade , Temperatura Ambiente , Animais , Mudança Climática , Feminino , Larva , Masculino
4.
J Agric Food Chem ; 67(38): 10553-10562, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31490076

RESUMO

Chlorpyrifos (CPF) is a widely used organophosphorus pesticide and detected frequently in fruits, vegetables, as well as in urine and blood in humans. Studies have suggested that CPF can induce metabolic disruption, such as type-2 diabetes mellitus and changed body weight. The main mechanisms are based on oxidative damage, fatty-acid synthesis, and lipid peroxidation. Studies have also shown that CPF can change reproductive hormone (RH) levels. CPF might result in metabolic disorders through altered RH levels. Here, we review the studies showing that CFP causes metabolic disruption. Then, we present the studies showing that CFP changes RH levels. Finally, we discuss a potential pathway of how CPF elicits metabolic disruption.


Assuntos
Clorpirifos/toxicidade , Hormônios Gonadais/metabolismo , Inseticidas/toxicidade , Doenças Metabólicas/metabolismo , Animais , Humanos , Peroxidação de Lipídeos , Doenças Metabólicas/etiologia
5.
Sci Total Environ ; 692: 1291-1303, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31539961

RESUMO

Pesticides are important contributors to the global freshwater biodiversity crisis. Among pesticides, neonicotinoids are the best-selling class of agricultural insecticides and are suspected to represent significant risks to freshwater and terrestrial ecosystems worldwide. Despite growing recognition that neonicotinoid impacts may be modified by the presence of additional stressors, there is limited information about their interactions with other agricultural stressors in freshwater ecosystems. We conducted an outdoor pond-mesocosm experiment to investigate the individual and interactive effects of nutrients, fine sediment, and imidacloprid (a neonicotinoid insecticide) inputs on freshwater community structure (density, diversity, and composition of zooplankton and benthic invertebrates) and ecosystem functioning (ecosystem metabolism, primary production, and organic matter decomposition). We hypothesized antagonistic nutrient-imidacloprid, and synergistic sediment-imidacloprid interactions, affecting aquatic invertebrate communities. The three stressors had significant individual and interactive effects on pond ecosystems. The insecticide neutralized the positive effects of nutrient additions on benthic invertebrate richness and mitigated the negative effects of sediment on zooplankton communities (antagonistic interactions). Moreover, we observed compensatory responses of tolerant benthic invertebrates, which resulted in reversal interactions between sediment and imidacloprid. Furthermore, our observations suggest that imidacloprid has the potential to increase net ecosystem production at environmentally relevant concentrations. Our findings support the hypothesis that the impacts of imidacloprid may be modified by other agricultural stressors. This has important implications on a global scale, given the widespread use of these pesticides in intensive agricultural landscapes and the growing body of literature suggesting that traditional pesticide assessment frameworks, based on laboratory toxicity tests alone, may be insufficient to adequately predict effects to complex freshwater ecosystems.


Assuntos
Organismos Aquáticos/fisiologia , Ecossistema , Inseticidas/toxicidade , Neonicotinoides/toxicidade , Poluentes Químicos da Água/toxicidade , Agricultura , Animais , Biodiversidade , Monitoramento Ambiental , Água Doce , Inseticidas/análise , Invertebrados/fisiologia , Neonicotinoides/análise , Nitrogênio , Fósforo , Poluentes Químicos da Água/análise , Zooplâncton
6.
Ecotoxicol Environ Saf ; 182: 109464, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31398777

RESUMO

Chlorpyrifos (CPF) is an environmental pollutant due to its high toxicity to aquatic animals. Because CPF was detected in aquatic environments in many countries, it has been widely concerned by researchers. Although the immunotoxicity of CPF to fish had been reported, the immunotoxicity mechanism is still not clear. Recently, transcriptome analysis has become a major method to study the toxic mechanism of pollutants in environmental toxicology. However, the immunotoxicity identification of CPF on fish had not been reported by transcriptome analysis. In the present study, we examined the effects of CPF on organismal system in the spleen of common carp by transcriptome analysis. We have successfully constructed a database of transcriptome analysis of carp spleens under exposure to CPF and found 773 differentially expressed genes (DEGs) (including 498 up-regulated DEGs and 275 down-regulated DEGs) and 4 branches (containing 33 known KEGG pathways). Some genes associated with the 4 pathways (Complement and coagulation cascades, PPAR signaling pathway, Fat digestion and absorption, and Collecting duct acid secretion) contained in organismal system were validated by quantitative real-time PCR and showed significant improvement compared with the control group. Our results indicated that exposure to CPF caused a change in the signal pathways of organismal system in carp spleens. The present study provides new insights into the immunotoxicity mechanism and risk assessment of CPF, as well as references for comparative medicine.


Assuntos
Clorpirifos/toxicidade , Baço/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Atrazina/toxicidade , Carpas , Sistema Imunitário/efeitos dos fármacos , Inseticidas/toxicidade , Transdução de Sinais , Baço/fisiologia
7.
J Vet Emerg Crit Care (San Antonio) ; 29(4): 424-430, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31257715

RESUMO

OBJECTIVE: To describe 2 cases of organophosphate intoxication through a previously unreported method of exposure. CASE SERIES: A 2-year-old intact male Australian Cattle Dog (case 1) presented with progressive muscarinic and nicotinic clinical signs, and a 3-year-old neutered male mixed breed dog (case 2) presented after known ingestion of cattle ear tags. The dog in case 1 was discovered to have ingested cattle ear tags after abdominal radiographs. Organophosphate testing of gastric contents confirmed diazinon toxicosis. The dog in case 2 was found to be eating ear tags by the owner. The tags in case 2 contained diazinon and coumaphos. The dog in case 1 was treated with gastric lavage, gastroprotectants, prokinetics, antiemetics, pralidoxime chloride, and atropine. The dog in case 2 was treated with pralidoxime chloride. Both patients received standard supportive and nursing care and recovered completely with no further concerns. NEW OR UNIQUE INFORMATION PROVIDED: This is a novel exposure to organophosphates that has not been reported in small animals. In dogs with relevant clinical signs and potential environmental exposure, cattle ear tag ingestion is an important differential diagnosis to consider.


Assuntos
Diazinon/toxicidade , Doenças do Cão/induzido quimicamente , Organofosfatos/toxicidade , Compostos de Pralidoxima/uso terapêutico , Animais , Bovinos , Cumafos/toxicidade , Doenças do Cão/terapia , Cães , Corpos Estranhos , Inseticidas/toxicidade , Masculino
8.
J Environ Sci Health B ; 54(7): 580-589, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31266377

RESUMO

This study aimed to compare the toxicity for fish of two active ingredients (lambda-cyhalothrin-20 g L-1, a pyrethroid, and acetamiprid-15 g L-1, a neonicotinoid) which are components of a commercial insecticide (Acer 35 EC) used in cotton crop in many West African countries. The juveniles of Oreochromis niloticus (4.01 ± 0.34 g, mean body weight) were exposed for 96 h to increasing concentrations of active ingredients (lambda-cyhalothrin and acetamiprid) or a mixture similar to Acer 35 EC (composed by 20 g of chemical compound lambda-cyhalothrin and 15 g of acetamiprid dissolved in 1 L of acetone). The experiments were carried out under controlled conditions in aquaria according to OECD Guidelines. During the experiments, the behavioral responses (loss of balance, color change, hyperactivity, etc.) that usually precede death were observed in exposed fish. Mortalities were recorded in each aquarium and the LC50-96h of each chemical was determined. The LC50-96h obtained were respectively 0.1268, 0.0029, 182.9 and 0.5685 ppm for Acer 35 EC, lambda-cyhalothrin, acetamiprid and mixture. All insecticides used in this study had profound impact on Nile tilapia behavior which may confirm the neurotoxicity of each single active compound as well as of their mixture.


Assuntos
Ciclídeos , Neonicotinoides/toxicidade , Nitrilos/toxicidade , Piretrinas/toxicidade , Animais , Comportamento Animal/efeitos dos fármacos , Ciclídeos/fisiologia , Sinergismo Farmacológico , Inseticidas/toxicidade , Dose Letal Mediana , Mortalidade , Testes de Toxicidade Aguda , Poluentes Químicos da Água/toxicidade
9.
Aquat Toxicol ; 214: 105237, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31276910

RESUMO

Chirality should be taken into consideration when assessing the effect of synthetic pyrethroids to aquatic environmental safety. In our study, 96 h acute toxicity assay showed that enantiomers of cis-BF had an addictive effect of toxicity on Xenopus laevis and R-cis-bifenthrin(R-cis-BF) had higher acute toxicity than S-cis-BF. In chronic assay, R-cis-BF exerted more toxic effect on behavior and development of tadpoles than S-cis-BF, and there was also enantioselective effect of cis-BF on antioxidant enzyme and LDH activity. Besides, thyroid development was also affected at the gene and hormone level, with varied effects observed with different exposure enantiomers. Moreover, in the enantioselective accumulation and tissue distribution of enantiomer assays, results showed that R-cis-BF had higher affinity to organisms than S-cis-BF. This study provided the evidence that chiral pesticides enantioselectively affected development of amphibians, and also shed light on the understanding of enantioselectivity in both acute and chronic eco-toxicities to improve risk assessment and regulation of chiral pesticides.


Assuntos
Comportamento Animal/efeitos dos fármacos , Biomarcadores/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Piretrinas/química , Piretrinas/toxicidade , Xenopus laevis/crescimento & desenvolvimento , Xenopus laevis/metabolismo , Animais , Antioxidantes/metabolismo , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Inseticidas/toxicidade , L-Lactato Desidrogenase/metabolismo , Larva/efeitos dos fármacos , Malondialdeído/metabolismo , Piretrinas/metabolismo , Estereoisomerismo , Hormônios Tireóideos/genética , Hormônios Tireóideos/metabolismo , Distribuição Tecidual/efeitos dos fármacos , Testes de Toxicidade Aguda , Poluentes Químicos da Água/toxicidade
10.
Environ Pollut ; 253: 11-18, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31302396

RESUMO

The use of insecticides based on metabolites found in live organisms, such as the insecticide spinosad, has been an option for the control of agricultural pests because of the allegedly low toxicological risk for nontarget arthropods, such as stingless bees. In the current study, we evaluate the effects of chronic oral exposure to spinosad during the larval phase on survival, developmental time, body mass, midgut epithelial remodeling, and the peritrophic matrix (PM) of Partamona helleri stingless bee workers. Worker larvae that were raised in the laboratory were orally exposed to different concentrations (0, 6.53, 13.06, 32.64, and 3,264 ng. a.i. bee-1) of spinosad (formulation), and the resulting survival, developmental time, and body mass were studied. The concentration of spinosad recommended for use in the field (3,264 ng. a.i. bee-1) reduced the survival of workers during development. Also, sublethal concentrations of spinosad delayed the development and caused morphological changes in the midgut epithelium. Finally, the chronic exposure of larvae to 32.64 ng. a.i. bee-1 spinosad also altered the remodeling of the midgut during metamorphosis and affected the organization of the PM of larvae, pupae, and adults. Our data suggest possible environmental risks for using spinosad in cultures that are naturally pollinated by stingless bees.


Assuntos
Crescimento e Desenvolvimento/efeitos dos fármacos , Himenópteros/crescimento & desenvolvimento , Inseticidas/toxicidade , Macrolídeos/toxicidade , Animais , Abelhas , Sistema Digestório , Combinação de Medicamentos , Himenópteros/efeitos dos fármacos , Larva/efeitos dos fármacos , Polinização
11.
Environ Pollut ; 253: 89-99, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31302406

RESUMO

Juvenile hormone analogue (JHA) insecticides are endocrine disrupters that interfere with hormonal action in insects by mimicking their juvenile hormones (JH). As the structure and functions of methyl farnesoate in crustaceans are similar to those of JH in insects, exogenous JHA insecticides could have adverse effects on the development and reproduction of crustaceans. This study examined the toxic effects of two JHA insecticides, fenoxycarb and methoprene, on a freshwater shrimp model of cherry shrimp, Neocaridina davidi. Both insecticides had detrimental effects on cherry shrimp, but fenoxycarb was more toxic than methoprene. Chronic exposure to these insecticides reduced the shrimp's body length and molting frequency. Based on transcriptome annotations for N. davidi, we identified important gene homologues that were active in both insect JH biosynthetic and degradative pathways as well as JH and ecdysteroid signaling pathways. Chronic treatments with JHAs had significant effects on these genes in N. davidi. Our transcriptomic analysis showed that genes involved in the pathways related to cuticle development, serine protease activity, and carbohydrate, peptide and lipid metabolic processes were differentially expressed in shrimp exposed to JHAs. These results demonstrate the toxicity of fenoxycarb and methoprene to freshwater crustaceans and indicate the need to monitor the use of JHA insecticides.


Assuntos
Decápodes (Crustáceos)/fisiologia , Inseticidas/toxicidade , Animais , Decápodes (Crustáceos)/metabolismo , Disruptores Endócrinos , Hormônios Juvenis , Metoprene , Muda/efeitos dos fármacos , Fenilcarbamatos , Reprodução/efeitos dos fármacos , Transcriptoma/efeitos dos fármacos
12.
J Agric Food Chem ; 67(28): 7793-7809, 2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31274315

RESUMO

Indoxacarb, a commercialized oxadiazine insecticide, nearly irreversibly blocks open/inactivated, but not resting sodium channels. The structure-activity relationships showed that the substituents at the position of the chiral atom in the oxadiazine ring are very important to the biological activity of oxadiazine insecticide. Here we synthesized a series of tricyclic oxadiazine 4a-methyl ester derivatives. The chiral atom in the oxadiazine ring has been epimerized and substituted with either pyrethric acid or cinnamic acid derivatives. Benzene ring in the tricyclic moiety was substituted with a chlorine, fluorine, or bromine atom, and nitrogen-linked benzene ring was substituted with a trifluoromethyl or trifluoromethoxy group. Toxicity of these compounds against Spodoptera litura F. was evaluated. Diastereoisomers of most toxic compounds J7 and J9 with pyrethric acid moiety were separated by flash column chromatography. The more polar diastereoisomers, J7-L-Rf and J9-L-Rf, and compounds J24 and J26 with cinnamic acid moiety exhibited highest insecticidal activities. We further used Monte Carlo energy minimizations to dock compound J7 and J24 in the NavMs-based homology model of the open cockroach sodium channel. In the low-energy binding modes, the compound interacted with residues in the inner pore and domain interfaces, which previously were proposed to contribute to receptors of pyrethroids and sodium channel blocker insecticides. Our results define compound J7 and J24 as a potentially useful optimized hit for the development of multiple sites sodium channel blocker or modulator.


Assuntos
Inseticidas/química , Inseticidas/toxicidade , Oxazinas/química , Oxazinas/toxicidade , Bloqueadores dos Canais de Sódio/química , Bloqueadores dos Canais de Sódio/toxicidade , Animais , Baratas/efeitos dos fármacos , Baratas/metabolismo , Descoberta de Drogas , Ésteres/química , Ésteres/farmacologia , Proteínas de Insetos/química , Proteínas de Insetos/metabolismo , Modelos Moleculares , Canais de Sódio/química , Canais de Sódio/metabolismo , Spodoptera/efeitos dos fármacos , Spodoptera/metabolismo , Relação Estrutura-Atividade
13.
Toxicol Lett ; 314: 124-132, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31362050

RESUMO

Organophosphates are chemical pollutants that are existed widely in the environment, but the reactions of these agents with blood proteins are still not fully clarified. The current story was to analyze the static and dynamic interactions between human serum albumin (HSA) and phenthoate and then uncover the impact of the conjugations on the acetylcholinesterase (AChE) activity at the microscopic scale. Experimental results revealed clearly that the bioconjugate of the HSA-phenthoate was yielded and the conformation of HSA can produce autoregulation during the reaction. Dynamic reaction processes suggested that the conformational flexibility of the specific protein domain was changed significantly in equilibrium, and the electrostatic interaction energy played a major role in total energy of the biosystems, which matches the results of wet experiment and molecular docking. We also found that the modes of homologous proteins-phenthoate have obvious distinctions, and this point is related closely to the local dynamic flexibility of biomolecular structures. Additionally, the degree of bioconjugation of the HSA-phenthoate is positively associated with the enzymatic activity of target AChE, which may be attributed to the competitive reactions between HSA and AChE. Evidently, this scenario could provide useful molecular information for the systematic exploration of the toxicokinetics of organophosphorus compounds.


Assuntos
Inibidores da Colinesterase/sangue , Inseticidas/sangue , Modelos Biológicos , Simulação de Acoplamento Molecular , Compostos Organotiofosforados/sangue , Albumina Sérica Humana/metabolismo , Acetilcolinesterase/química , Acetilcolinesterase/metabolismo , Sítios de Ligação , Ligação Competitiva , Inibidores da Colinesterase/química , Inibidores da Colinesterase/toxicidade , Humanos , Inseticidas/química , Inseticidas/toxicidade , Compostos Organotiofosforados/química , Compostos Organotiofosforados/toxicidade , Ligação Proteica , Conformação Proteica , Domínios Proteicos , Albumina Sérica Humana/química
14.
Environ Pollut ; 252(Pt A): 205-215, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31151059

RESUMO

This study aimed to evaluate and qualify field-based potential risks of seven neonicotinoid and phenylpyrazole (fipronil) insecticides on aquatic invertebrates, including estuary-resident marine crustaceans. One hundred and ninety-three estuarine water samples, with salinity ranging from 0.5 to 32.7, were collected from four estuarine sites in the Seto Inland Sea of Japan, in 2015-2018 and the insecticide levels were measured. Five neonicotinoid and fipronil insecticides were successfully identified, and their occurrence varied temporally. Marine crustaceans were simultaneously harvested every month from one of the estuarine water sampling sites in 2015-2017. Three predominant crustacean species, kuruma prawn (Penaeus japonicus), sand shrimp (Crangon uritai), and mysid (Neomysis awatschensis), were captured and their seasonal presence was species independent. A 96-h laboratory toxicity study with the insecticides using kuruma prawn, sand shrimp, and a surrogate mysid species (Americamysis bahia) indicated that fipronil exerted the highest toxicity to the three crustaceans. Using both toxicity data and insecticide occurrence in estuarine water (salinity ≥10, n = 169), the potential risks on the three marine crustaceans were quantified by calculating the proportion of mixture toxicity effects (Pmix). The Pmix of seven neonicotinoids on the crustaceans was less than 0.8%, which is likely to be too low to indicate adverse effects caused by the insecticides. However, short temporal detection of fipronil (exclusively in June and July) significantly affected the Pmix, which presented the maximal Pmix values of 21%, 3.4%, and 72% for kuruma prawn, sand shrimp, and mysid, respectively, indicating a significant effect on the organisms. As for estuarine water (salinity <10), some water samples contained imidacloprid and fipronil exceeding the freshwater benchmarks for aquatic invertebrates. The present study provides novel insights into the seasonally varying risks of insecticides to estuarine crustaceans and highlights the importance of considering whether ecological risk periods coincide with crustacean presence.


Assuntos
Crangonidae/efeitos dos fármacos , Inseticidas/análise , Neonicotinoides/análise , Nitrocompostos/análise , Penaeidae/efeitos dos fármacos , Pirazóis/análise , Poluentes Químicos da Água/toxicidade , Animais , Ecologia , Estuários , Água Doce/química , Inseticidas/toxicidade , Japão , Neonicotinoides/toxicidade , Nitrocompostos/toxicidade , Pirazóis/toxicidade , Poluentes Químicos da Água/análise
15.
Bull Environ Contam Toxicol ; 103(3): 405-410, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31203409

RESUMO

Global trends in pesticide use can increase aquatic pollution and affect resident fisheries. Crabs exposed to organophosphate pesticides, such as chlorpyrifos, may increase production of reactive oxygen species (ROS), affecting the pro-oxidant/antioxidant balance. Zichiopsis collastinensis crabs were exposed to environmentally relevant concentrations of chlorpyrifos (0.1 and 0.5 µg L-1). Effects on the oxidative stress enzymes catalase, superoxide dismutase, glutathione S-transferases, glutathione reductase, and on thiobarbituric acid reactive substances and hydrogen peroxide concentrations were evaluated at four intervals during 96 h exposures. Exposures caused decreased GST activity and increased H2O2 levels in gills. There were modifications of GST, CAT and SOD activities in the hepatopancreas after 12 h of exposure, and an increase of H2O2 levels at every exposure interval observed. The present study proved that chlorpyrifos lead to oxidative stress in Z. collastinensis. However other enzymatic/non-enzymatic responses should be further investigated in order to be included as part of a battery of biomarkers, together with H2O2 levels, which is a parameter highly recommended to be taken into account.


Assuntos
Braquiúros/fisiologia , Clorpirifos/toxicidade , Inseticidas/toxicidade , Animais , Antioxidantes/metabolismo , Biomarcadores/metabolismo , Braquiúros/metabolismo , Catalase/metabolismo , Clorpirifos/metabolismo , Monitoramento Ambiental , Água Doce , Brânquias/metabolismo , Glutationa Redutase/metabolismo , Hepatopâncreas/enzimologia , Peróxido de Hidrogênio/metabolismo , Inseticidas/metabolismo , Estresse Oxidativo/fisiologia , Praguicidas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Alimentos Marinhos , Superóxido Dismutase/metabolismo , Poluentes Químicos da Água/toxicidade
16.
Ecotoxicology ; 28(6): 680-685, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31218496

RESUMO

The toxicity of an organophosphorus (OP) insecticide, methyl parathion (MP), and its hydrolysis product, p-nitrophenol (PNP), to the native Australian cladoceran species, Daphnia carinata, was assessed. Both MP and PNP were stable in cladoceran water during the test period. D. carinata was sensitive to both MP and PNP; however, the parent compound was more toxic than its metabolite. This is the first study that demonstrated the acute toxicity of MP and PNP towards an Australian daphnid species. The present investigation emphasizes the need for including the native taxa as non-target test organisms while evaluating the toxicity of environmental pollutants.


Assuntos
Daphnia/efeitos dos fármacos , Inseticidas/toxicidade , Metil Paration/toxicidade , Nitrofenóis/toxicidade , Animais , Austrália , Relação Dose-Resposta a Droga , Testes de Toxicidade Aguda
17.
Life Sci ; 231: 116534, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31173782

RESUMO

N-acetylcysteine (NAC) has largely been used as an effective chemo- protective agent owing to their beneficial effect in restoring several physiological parameters and relieving oxidative stress. Interestingly, it has been suggested that NAC mechanisms of action extend beyond being a precursor to the antioxidant glutathione and that they may involve several neurotropic and inflammatory pathways. Exposure to fenitrothion, an organophosphorus insecticide, promotes oxidative stress and induces several deleterious changes in the immune response and various tissues including cerebrum and spleen. The main objective of our study was to investigate ameliorative efficacy of N-acetylcysteine for immunological and neurological alterations and oxidative DNA damage induced by fenitrothion toxicity in cerebrum and spleen tissues of male rats. Our results revealed that oral exposure to fenitrothion for 30 days caused a reduction in the erythrocyte count in addition to leukocytosis, lymphocytosis, and neutrophilia. Also, this route of administration increased the serum levels of LDH, TNF-α, and IL-2 with reduction in serum immunoglobulins (IgG & IgM) concentrations. Furthermore, a significant downregulation in the antioxidant markers (GSH & SOD) with an elevation of free radical (MDA) levels were noticed. Regarding the brain, fenitrothion administration inhibited AchE activity and increased brain GABA, serotonin and dopamine levels. Moreover, it induced an elevation in oxidative DNA damage indicated by 8-hydroxy 2-deoxyguanosine (8OH2dG) and mRNA expression of pro-apoptotic genes, including Bax, and p53, but Bcl-2 expression was reduced. N-acetylcysteine co-treatment restored the normal physiological tone in most of these parameters. Immunostaining for GFAP and Caspase-3 markers in the brain and spleen tissues were increased respectively. In conclusion, N-acetylcysteine supplementation has an ameliorative effect against immunotoxic, neurotoxic and oxidative DNA damage induced by fenitrothion exposure.


Assuntos
Acetilcisteína/farmacologia , Encéfalo/efeitos dos fármacos , Dano ao DNA , Fenitrotion/toxicidade , Inseticidas/toxicidade , Baço/efeitos dos fármacos , Animais , Antioxidantes/farmacologia , Encéfalo/metabolismo , Caspase 3/metabolismo , Interações de Medicamentos , Fenitrotion/administração & dosagem , Inseticidas/administração & dosagem , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Baço/metabolismo
18.
Sci Total Environ ; 685: 690-701, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31203163

RESUMO

Neonicotinoids (NEOCs) are insecticides that are widely used worldwide in the culture of maize and soya. Whereas they specifically target terrestrial insects by acting as agonists of the neurotransmitter acetylcholine in their nervous system, their effects on the cholinergic system of vertebrates is still unclear. Moreover, there is an increasing concern about their effects on aquatic biota because of their high leaching potential. In the agricultural watershed of Lake St. Pierre (LSP) (St. Lawrence River System, Québec, Canada), for example, NEOC concentrations considered toxic for aquatic biota (>8.3 ng L-1) have frequently been detected. These conditions may affect the yellow perch (Perca flavescens) population in LSP, which collapsed in the mid 1990s and is now experiencing poor recruitment. Moreover, because their larvae are found in shallow waters (<80 cm) near agricultural land, they are also exposed to ultraviolet radiation (UVR), with unknown potential interactions with NEOCs. The objective of this study was to test the synergistic effects of two commonly used NEOCs (imidacloprid and thiamethoxam) with natural UVR on yellow perch larvae using survival analysis and biomarkers to better quantify lethal and sublethal effects. Three common garden experiments were conducted with thiamethoxam and/or imidacloprid and natural UVR following a factorial design. Our results showed an interaction between UVR and thiamethoxam in terms of larval mortality. At the sublethal level, imidacloprid was associated with increased protein content and, in the presence of UVR, with increased acetylcholinesterase activity, thus indicating a cholinergic perturbation like that found in insects. Finally, we also found unexpected reduced lipid peroxidation associated with imidacloprid. A reduction in the overall lipid accumulation is suspected to be behind this puzzling result. These results will open new research avenues related to the effects of NEOCs on proteins and lipid accumulation.


Assuntos
Neonicotinoides/toxicidade , Percas/fisiologia , Poluentes Químicos da Água/toxicidade , Animais , Radiação de Fundo , Inseticidas/toxicidade , Peroxidação de Lipídeos , Nitrocompostos/toxicidade , Quebeque , Tiametoxam/toxicidade , Raios Ultravioleta
19.
Arch Insect Biochem Physiol ; 101(4): e21588, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31180585

RESUMO

Boric acid (BA) is widely used in various industrial process and can be accessed to nontarget organisms. This study aimed to investigate the insecticidal effects of BA and its toxic activities with respect to immunologic and genotoxic effects using Galleria mellonella larvae as a model. BA concentrations (78.125-10,000 ppm) were administrated to the larvae using the feeding method. Concentration-dependent mortality was observed in all larval groups. Probit analysis revealed LC30 , LC50 , and LC70 values to be 112.4, 320.1, and 911.4 ppm, respectively. These concentrations were used in all bioassays. Drastic reductions in total hemocyte counts along with changes in differential hemocyte counts were observed following BA treatment. Cell viability assays showed dose-dependent reductions in viable cells and an increase in the necrotic and apoptotic ratios after BA treatment. However, mitotic indices of larval hemocytes did not change at all BA concentrations. The cytotoxic effect of BA led to a significant reduction in cellular immune responses such as encapsulation, melanization, and nodulation activities of treated larvae. While BA increased micronucleus ratios at the highest concentration, comet parameters indicating DNA damage increased in G. mellonella larval hemocytes at all concentrations. These report that BA suppresses the immune system of G. mellonella and also poses risks of genotoxicity at high concentrations.


Assuntos
Ácidos Bóricos/toxicidade , Mariposas/efeitos dos fármacos , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Ensaio Cometa , Relação Dose-Resposta a Droga , Hemócitos/efeitos dos fármacos , Hemolinfa , Inseticidas/toxicidade , Larva/efeitos dos fármacos , Larva/genética , Larva/imunologia , Testes para Micronúcleos , Mariposas/genética , Mariposas/imunologia
20.
Ecotoxicol Environ Saf ; 181: 121-129, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31176246

RESUMO

Biocides based on toxins of Bacillus thuringiensis var. israelensis (Bti) are established as alternatives to conventional chemical insecticides for mosquito control all across the globe since they are regarded ecologically compatible and harmless to non-target species. Since recent studies on amphibian larvae have called this opinion into question, we exposed Rana temporaria tadpoles to single (1 mg/L), tenfold (10 mg/L) and hundredfold (100 mg/L) field concentrations of VectoBac® WG (a water dispersible granule Bti formulation) in the laboratory for eleven days to investigate whether larvae were adversely affected by Bti and its endotoxin proteins. In addition to a negative (water) control, a positive control based on organic rice protein (50 mg/L) was run to check for the nutritional relevance of Bti proteins. There was no Bti-related mortality and a histopathological analysis of tadpole intestines revealed no adverse effects. Analyses of biomarkers for proteotoxicity (stress protein family, Hsp70) and neurotoxicity or metabolic action (b-esterases acetylcholine esterase (AChE) and carboxylesterases) revealed no significant differences between Bti treatments and the negative control. The responses of tadpoles in the protein-supplemented positive control differed from those of the negative control and the Bti treatments. Tadpoles in the positive control had reduced body mass and elevated AChE activity.


Assuntos
Bacillus thuringiensis , Endotoxinas/toxicidade , Inseticidas/toxicidade , Rana temporaria/crescimento & desenvolvimento , Animais , Larva/efeitos dos fármacos , Controle Biológico de Vetores
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