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1.
Aquat Toxicol ; 227: 105612, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32911328

RESUMO

Lambda-cyhalothrin is a synthetic pyrethroid that mimics the structure and insecticidal properties of pyrethrin, a natural insecticide derived from chrysanthemums. In fish, it disrupts the nervous system, causing motor paralysis and several other alterations associated with varying levels of mortality. This study aimed to evaluate osmoregulatory responses and histological changes in the gills of Oreochromis niloticus chronically exposed to a sublethal dosage (0.86 µg/L) of lambda-cyhalothrin. The mean serum values for Na2+, K+, Cl-, Ca2+, pH, lactate, H+, HCO3, and glucose along to degree of tissue change (DTC) at 24, 96, 168, and 240 h post-exposure (hpe) were evaluated. Lambda-cyhalothrin affected the neuronal motor function at 24 hpe, followed by the increase of the K+, Ca2+, H+, and glucose levels in the exposed group, compared to the control group. Lactate and H+ levels in the exposed group were higher than those in the control group at 168 and 240 hpe respectively. HCO3, and Cl- levels increased at 240 hpe, although there was no change in the pH values. DTC was higher in treated fish than in control fish, but there were no significant differences among time-exposure. The changes detected ranged from hyperemia of the branchial vasculature, eosinophilic granulocytic cell infiltration, mucous cell hyperplasia, and partial fusion of secondary lamellae at 24 hpe to vascular aneurysm formation, and necrosis of the lamellar epithelium at 240 hpe. Thus, a sublethal dosage of lambda-cyhalothrin in the long-term is toxic for Nile tilapia, characterized by hypokalemia, hypercalcemia, hyperglycemia, and respiratory alkalosis, followed by time-dependent histological changes.


Assuntos
Ciclídeos/fisiologia , Nitrilos/toxicidade , Piretrinas/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Brânquias/patologia , Inseticidas
2.
Mar Environ Res ; 159: 105007, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32662438

RESUMO

This study investigated effects of sea lice pharmaceuticals on egg-bearing deep-water shrimp (Pandalus borealis). Both mortality and sub-lethal effects (behavior, embryo development, and reproductive output) were studied for each of three pharmaceuticals alone and in different sequential combinations. The most severe effect was observed for deltamethrin where 2 h exposure to 330 times diluted treatment dose (alone and in sequential application with hydrogen peroxide and azamethiphos) induced almost 100% mortality within a few days after exposure. Similar effects were not observed for hydrogen peroxide or azamethiphos. However, sequential treatment of hydrogen peroxide and azamethiphos (2 h exposure to each pharmaceutical; 500 times dilution) resulted in >40% mortality during the first week following treatment. No sub-lethal effects or loss of eggs in female shrimp could be related to exposure to the bath treatments. Future studies should investigate potential sub-lethal effects at exposure concentrations close to the no-effect concentration.


Assuntos
Copépodes , Nitrilos , Pandalidae , Piretrinas , Animais , Peróxido de Hidrogênio , Nitrilos/toxicidade , Organotiofosfatos/toxicidade , Piretrinas/toxicidade
3.
Toxicol Lett ; 332: 192-201, 2020 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-32693020

RESUMO

Fenvalerate, a synthetic pyrethroid insecticide, is an environmental endocrine disruptor and neurodevelopmental toxicant. An early report found that pubertal exposure to high-dose fenvalerate impaired cognitive and behavioral development. Here, we aimed to further investigate the effect of pubertal exposure to low-dose fenvalerate on cognitive and behavioral development. Mice were orally administered with fenvalerate (0.2, 1.0 and 5.0 mg/kg) daily from postnatal day (PND) 28 to PND56. Learning and memory were assessed by Morris water maze. Anxiety-related activities were detected by open-field and elevated plus-maze. Increased anxiety activities were observed only in females exposed to fenvalerate. Spatial learning and memory were damaged only in females exposed to fenvalerate. Histopathology observed numerous scattered shrinking neurons and nuclear pyknosis in hippocampal CA1 region. Neuronal density was reduced in hippocampal CA1 region of fenvalerate-exposed mice. Mechanistically, hippocampal thyroid hormone receptor (TR)ß1 was down-regulated in a dose-dependent manner in females. In addition, TRα1 was declined only in females exposed to 5.0 mg/kg fenvalerate. Taken together, these suggests that pubertal exposure to low-dose fenvalerate impairs cognitive and behavioral development in a gender-dependent manner. Hippocampal TR signaling may be, at least partially, involved in fenvalerate-induced impairment of cognitive and behavioral development.


Assuntos
Transtornos Cognitivos/induzido quimicamente , Hipocampo/metabolismo , Inseticidas/toxicidade , Nitrilos/toxicidade , Piretrinas/toxicidade , Transdução de Sinais/efeitos dos fármacos , Hormônios Tireóideos , Animais , Ansiedade/induzido quimicamente , Ansiedade/psicologia , Peso Corporal/efeitos dos fármacos , Região CA1 Hipocampal/efeitos dos fármacos , Região CA1 Hipocampal/metabolismo , Transtornos Cognitivos/psicologia , Relação Dose-Resposta a Droga , Regulação para Baixo/efeitos dos fármacos , Ingestão de Alimentos/efeitos dos fármacos , Disruptores Endócrinos , Feminino , Hipocampo/efeitos dos fármacos , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos ICR , Neurônios/patologia , Receptores dos Hormônios Tireóideos/efeitos dos fármacos , Caracteres Sexuais
4.
PLoS Biol ; 18(6): e3000633, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32584814

RESUMO

Mitigating the threat of insecticide resistance in African malaria vector populations requires comprehensive information about where resistance occurs, to what degree, and how this has changed over time. Estimating these trends is complicated by the sparse, heterogeneous distribution of observations of resistance phenotypes in field populations. We use 6,423 observations of the prevalence of resistance to the most important vector control insecticides to inform a Bayesian geostatistical ensemble modelling approach, generating fine-scale predictive maps of resistance phenotypes in mosquitoes from the Anopheles gambiae complex across Africa. Our models are informed by a suite of 111 predictor variables describing potential drivers of selection for resistance. Our maps show alarming increases in the prevalence of resistance to pyrethroids and DDT across sub-Saharan Africa from 2005 to 2017, with mean mortality following insecticide exposure declining from almost 100% to less than 30% in some areas, as well as substantial spatial variation in resistance trends.


Assuntos
Resistência a Inseticidas , Malária/parasitologia , Mosquitos Vetores/parasitologia , África , DDT/toxicidade , Resistência a Inseticidas/efeitos dos fármacos , Aprendizado de Máquina , Mosquitos Vetores/efeitos dos fármacos , Nitrilos/toxicidade , Fenótipo , Prevalência , Piretrinas/toxicidade , Análise Espaço-Temporal
5.
Chemosphere ; 257: 127162, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32485514

RESUMO

Deltamethrin is used widely in Eriocheir sinensis aquaculture to remove wild fish and parasites. The residual deltamethrin greatly affects the growth and quality of E. sinensis. In this study, the LC50 of deltamethrin against E. sinensis at 24, 48 and 96 h was determined to be 6.5, 5.0 and 2.8 µg/L, respectively. The enzyme activity and gene transcription of SOD, CAT, and PO in the hepatopancreas of E. sinensis after deltamethrin stimulation showed an increasing tendency, and these enzymes reached their maximum activities at 6-10 d. The MDA content accumulated with increased time of deltamethrin stress. After 15 d of deltamethrin stress, the hepatopancreas of E. sinensis was found to be damaged based on HE staining. These results showed that deltamethrin is highly toxic to E. sinensis. But the half-life of deltamethrin is long and mainly relies on biodegradation. To resolve the pollution of residual deltamethrin, a strain of deltamethrin-degrading bacteria, P-2, was isolated from the sediment of an E. sinensis culture pond. Through morphological observation, physiological and biochemical identification and 16S rDNA sequence analysis, we found that this strain belonged to Paracoccus sp. When the pH was 7, the substrate concentration was low, the inoculation amount was high, and the deltamethrin degradation effect of Paracoccus sp. P-2 was good. The deltamethrin residue in the hepatopancreas and muscle of E. sinensis decreased significantly when Paracoccus sp. P-2 was added at 6.0 × 108 CFU/L. The degradation efficiency of Paracoccus sp. P-2 in the hepatopancreas and muscle was more than 70%. These results showed that Paracoccus sp. P-2, the first deltamethrin-degrading bacterium in aquaculture, could be used to remove residual deltamethrin and improve the food safety of E. sinensis.


Assuntos
Braquiúros/fisiologia , Inseticidas/toxicidade , Nitrilos/toxicidade , Piretrinas/toxicidade , Animais , Aquicultura , Bactérias , Biodegradação Ambiental , Braquiúros/metabolismo , Hepatopâncreas/metabolismo , Inseticidas/metabolismo , Dose Letal Mediana , Nitrilos/metabolismo , Paracoccus/genética , Paracoccus/isolamento & purificação , Paracoccus/metabolismo , Polímeros , Piretrinas/metabolismo
6.
Aquat Toxicol ; 225: 105527, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32599436

RESUMO

A diverse range of chemicals are used in agriculture to increase food production on a large scale, and among them is the use of pesticides such as chlorothalonil, a broad-spectrum fungicide used in the control of foliar fungal diseases. This study aimed to elucidate the effects of chlorothalonil on biochemical biomarkers of oxidative stress in tissues of the fish Danio rerio. To achieve this, animals were exposed for 4 and 7 days, to nominal concentrations of chlorothalonil at 0 µg/L (DMSO, 0.001%), 0.1 µg/L and 10 µg/L, and after the exposure period, the tissues (gills and liver) were removed for biochemical analysis. Antioxidant capacity against peroxyl radicals (ACAP) and enzyme activities, such as superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST) and glutamate cysteine ligase (GCL), were evaluated in both tissues. In addition, the concentration of reactive oxygen species (ROS), reduced glutathione (GSH) and lipid peroxidation (LPO) levels were also analysed. A significant increase in ROS concentration, ACAP levels, GST and GCL activities and a significant reduction of LPO levels in gills exposed to the highest concentration were observed after 4 days. However, there was a significant reduction of ACAP and CAT activity, as well as a significant increase of GST activity and LPO levels in gills exposed to the lower concentration after 7 days. The liver was less affected, presenting a significant reduction in CAT activity and LPO levels after 4 days. However, a significant increase in SOD activity and LPO levels occurred after 7 days. These results indicate that chlorothalonil, after 4 days, caused activation of the antioxidant defence system in gills of animals exposed to the highest concentration. However, after 7 days, the lowest concentration of this compound caused oxidative stress in this same organ. Also, the results show that gills were more affected than the liver, probably because gills can be involved in chlorothalonil metabolisation. Therefore, it is possible that the liver could be exposed to lower chlorothalonil concentrations or less toxic metabolites due to the metabolism taking place in the gills.


Assuntos
Antioxidantes/metabolismo , Fungicidas Industriais/toxicidade , Nitrilos/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/metabolismo , Animais , Catalase/metabolismo , Brânquias/efeitos dos fármacos , Brânquias/enzimologia , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Glutationa Transferase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Peróxidos/metabolismo , Superóxido Dismutase/metabolismo
7.
Chemosphere ; 258: 127383, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32559491

RESUMO

The application of pesticides typically leads to lethal and sublethal exposure of non-target insects. Whereas our current understanding of these sublethal effects typically focuses on reproductive and physiological parameters, recent works emphasize that sublethal effects on behaviors such as maternal care could be of major importance in non-target species. However, it remained unknown whether these sublethal effects occur in insects. Here, we tested if exposure to sublethal doses of deltamethrin - a pyrethroid insecticide commonly used in crops - alters the expression of maternal egg care in females of the European earwig Forficula auricularia, a predator insect and pest control. Our results first reveal that deltamethrin exposure impaired the expression of three forms of maternal egg care: It decreased the likelihood of mothers to gather their otherwise scattered clutch of eggs, increased the time during which the female abandoned the clutch after a predator attack and reduced egg grooming duration. These sublethal effects did not reflect a lower activity of deltamethrin-exposed females, as these females increased their expression of self-grooming, and deltamethrin exposure did not affect females' exploration and mobility. Finally, we found that the negative effects of deltamethrin on egg care did not modify egg development, hatching rate and juvenile weight, possibly due to the transient effects of deltamethrin on maternal behaviors. Overall, our results reveal that sublethal exposure to a pesticide may diminish maternal egg care in a natural pest control and call for the integration of this measurement in assays on pesticides application.


Assuntos
Comportamento Animal/efeitos dos fármacos , Insetos/efeitos dos fármacos , Inseticidas/toxicidade , Comportamento Materno/efeitos dos fármacos , Nitrilos/toxicidade , Óvulo/crescimento & desenvolvimento , Piretrinas/toxicidade , Animais , Relação Dose-Resposta a Droga , Feminino , Insetos/fisiologia , Reprodução/efeitos dos fármacos
8.
J Environ Sci Health B ; 55(8): 719-725, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32538258

RESUMO

The industrialization of the agricultural sector has significantly increased the use of chemicals such as pesticides. Therefore, exposure to them is unavoidable, which makes it necessary to assess their safety for humans at actual exposure doses. This paper aims to determine toxicity of three types of pesticides toward human immune cells (HL-60 and U-937): glyphosate (GLY), deltamethrin (DEL), and chlorothalonil (CHL). Cell viability, membrane integrity, inflammation induction, and antioxidant activity were evaluated to determine differences in cellular response to the tested plant protection agents. In experimental models, all tested substances caused increased mortality of cells after only 24 h. Cell membrane damage was recorded under DEL and CHL influences. The largest disintegration of the cell membrane was due to the action of 100 µg/mL DEL for U-937 and CHL at 1 µg/mL for HL-60. GLY at a concentration of 3,600 µg/mL caused significant peroxidation of U-937 cells' lipids. CHL-induced inflammation in both types of cells tested. DEL and GLY also induced antioxidant activity in cells. These results lead to the conclusion that the tested pesticides act cytotoxically to the cells of the human immune system in doses to which both farmers and consumers are exposed.


Assuntos
Glicina/análogos & derivados , Sistema Imunitário/efeitos dos fármacos , Nitrilos/toxicidade , Praguicidas/toxicidade , Piretrinas/toxicidade , Agricultura , Antioxidantes/metabolismo , Membrana Celular/efeitos dos fármacos , Membrana Celular/imunologia , Sobrevivência Celular/efeitos dos fármacos , Fazendeiros , Glicina/toxicidade , Células HL-60 , Humanos , Sistema Imunitário/citologia , Peroxidação de Lipídeos/efeitos dos fármacos , Exposição Ocupacional , Testes de Toxicidade
9.
Toxicology ; 440: 152488, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32387285

RESUMO

Exposure to pyrethroids, a popular insecticide class that targets voltage-gated Na+ (Nav) channels, has been correlated to an increase in diagnosis of neurodevelopmental disorders, such as attention deficit hyperactive disorder (ADHD), in children. Dysregulation of medium spiny neurons (MSNs) firing in the nucleus accumbens (NAc) is thought to play a critical role in the pathophysiology of ADHD and other neurodevelopmental disorders. The Nav1.6 channel is the primary molecular determinant of MSN firing and is sensitive to modification by pyrethroids. Building on previous studies demonstrating that deltamethrin (DM), a commonly used pyrethroid, leads to use-dependent enhancement of sodium currents, we characterized the effect of the toxin on long-term inactivation (LTI) of the Nav1.6 channel, a parameter known to affect neuronal firing, and characterized changes in MSN intrinsic excitability. We employed whole-cell patch-clamp electrophysiology to measure sodium currents in HEK-293 cells stably expressing Nav1.6 channels and intrinsic excitability of MSNs in the brain slice preparation. We found that in response to repetitive stimulation acute exposure to 10 µM DM potentiated a build-up of residual sodium currents and modified availability of Nav1.6 by inducing LTI. In the NAc, DM modified MSN intrinsic excitability increasing evoked action potential firing frequency and inducing aberrant action potentials with low amplitude and depolarized voltage threshold, phenotypes that could be explained by DM induced changes on the Nav1.6 channel. These results provide a potential initial mechanism of toxicity of DM that could lead to disruption of the NAc circuitry overtime, increasing the risk of ADHD and other neurodevelopmental disorders.


Assuntos
Inseticidas/toxicidade , Canal de Sódio Disparado por Voltagem NAV1.6/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Nitrilos/toxicidade , Núcleo Accumbens/efeitos dos fármacos , Piretrinas/toxicidade , Bloqueadores dos Canais de Sódio/farmacologia , Potenciais de Ação/efeitos dos fármacos , Animais , Transtorno do Deficit de Atenção com Hiperatividade/metabolismo , Fenômenos Eletrofisiológicos/efeitos dos fármacos , Células HEK293 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Núcleo Accumbens/citologia , Técnicas de Patch-Clamp , Sódio/metabolismo
10.
J Environ Sci Health B ; 55(7): 669-676, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32396780

RESUMO

This study was designed to evaluate the acute toxicity of acetamiprid (neonicotinoid) and lambda-cyhalothrin (pyrethroid), individually and mixtures (Act-LCh mixture and Acer 35 EC®, 15 g/L of acetamiprid and 20 g/L of lambda-cyhalothrin) in African catfish juveniles (3.35 ± 0.75 g). The tests were conducted in the laboratory under semi-static conditions according to OECD Guideline 203. Mixture toxicity effects as a function of lethal concentrations were assessed using the additive index (AI) method. Acetamiprid with 96 h-LC50 = 265.7 ppm can be considered to be nontoxic for this species. However, lambda-cyhalothrin was highly toxic to C. gariepinus with 96 h-LC50 = 0.00083 ppm. Acer 35 EC® was less toxic (96 h-LC50 = 0.21 ppm) than the Act-LCh mixture (96 h-LC50 = 0.043 ppm). Marked changes indicating nervous system damage were also recorded. An antagonistic effect was shown for lethal concentrations leading to 5 to 15% mortality in 96 hours (96 h-LC5-15) while an additive effect was obtained for the 96 h-LC20-50. The results indicate that ecological risk assessment of these molecules in aquatic environments should consider their contamination levels. Moreover, particular attention to behavior changes related to their neurotoxicity is recommended for additional monitoring of the negative effects of these insecticides.


Assuntos
Peixes-Gato , Neonicotinoides/toxicidade , Nitrilos/toxicidade , Piretrinas/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Comportamento Animal/efeitos dos fármacos , Ecotoxicologia/métodos , Inseticidas/toxicidade , Dose Letal Mediana , Mortalidade , Testes de Toxicidade Aguda
11.
Aquat Toxicol ; 222: 105453, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32112997

RESUMO

Anti-parasitic drugs used in the aquaculture industry are discharged to the sea after treatment of salmon. In this study, the effects of azamethiphos (AZA) in the Salmosan® formulation and deltamethrin (DEL) in the Alpha Max® formulation, have been assessed in Northern shrimp larvae (Pandalus borealis) when administered both separately and in combination. The exposure concentrations were 100 ng/L for AZA and 2 ng/L for DEL, each representing a 1000-fold dilution of the prescribed concentrations for salmon. These two chemicals were combined at these concentrations to give a third treatment (AZA + DEL). When larvae were exposed for two hours on the first, second and third days post hatch (dph), significantly increased mortality and reduced swimming activity were observed for larvae from the DEL and combined AZA + DEL treatments 4 dph, though not in larvae from the AZA treatment. A single pulse exposure, delivered on the first day post hatch, caused similar effects on mortality and swimming activity 4 dph as the three-pulse exposure. Mortality was driven by the presence of DEL in both experiments, with no amplification or reduction of effects observed when DEL and AZA were combined. Larvae were observed for 13 days following the single pulse exposure, with food limitation introduced as an additional stressor on day 4. In the DEL and AZA + DEL treatments mortality continued to increase regardless of food level, with no larvae completing development to stage II. The overriding toxicity of DEL masked any potential effects the reduced food ration may have exerted. Swimming activity was lower for AZA treated larvae than Control larvae 13 dph, when both groups were fed daily, though no other significant changes to mortality, development to stage II, feeding rate or gene expression were observed. Food limited Control and AZA larvae had lower swimming activity and feeding rate than daily fed Control larvae, with expression of pyruvate kinase and myosin genes also downregulated. However, there was no negative effect on survival or successful development to stage II in these treatments. In addition, mesencephalic astrocyte-derived neurotropic factor was downregulated in food limited Control larvae when compared with the daily fed Controls. Results from this study together with reported estimates of dispersion plume concentrations of discharged pesticides indicate that toxic concentrations of deltamethrin could reach shrimp larvae several kilometers from a treated salmon farm.


Assuntos
Ração Animal , Aquicultura/métodos , Larva/efeitos dos fármacos , Pandalidae/efeitos dos fármacos , Praguicidas/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Nitrilos/toxicidade , Organotiofosfatos/toxicidade , Piretrinas/toxicidade , Salmão/crescimento & desenvolvimento
12.
Ecotoxicol Environ Saf ; 193: 110318, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32105945

RESUMO

The current study aimed to examine, for the first time, the relationship between exposure to deltamethrin (DLM) and atherogenic lipid profile disorders in adult Wistar rats, as well as, to verify the mechanism of the beneficial role of Zygophyllum album leaves extracts (ZALE). The experimental study was assessed using DLM (4 mg/kg b.w) either alone or co administered with ZALE (400 mg/kg b.w) orally for 90 days in rats. RP-HPLC-DAD-ESI-QTOF-MS was used to identify the bioactive metabolites present in ZALE. Plasmatic and aortic total cholesterol (TC), LDL-cholesterol (LDL-C), native LDL (LDL-apo B-100) and oxidized LDL (ox-LDL) were evaluated using auto-analyzer and a sandwich ELISA, respectively. The protein expressions of LDLR (native LDL receptor) and CD36 (Scavenger receptor class B) were evaluated in aorta or liver with a Western blot. The pathology has been confirmed with lipid stain (Oil Red O). Phytochemicals analysis revealed the presence of fifteen saponins in ZALE. Rats intoxicated with DLM revealed a significant increase in plasmatic and aortic lipid profile (TC, LDL-C, LDL-apo B-100 and ox-LDL), as well as, the concentration of the plasmatic cytokines include TNF-α, IL-2 and IL-6, compared to control. Hepatic native LDL and aortic CD36 receptor expression were increased in DLM treated group, however aortic LDL-R does not present any modification, when compared to control. The detected disturbances in lipid parameters were supported by Oil Red O applied. Due to their antioxidant activity, the bioactive compounds in ZALE as powerful agents able to prevent the pro-atherogenic effect observed in DLM-treated animals. These metabolites modulated most of inflammatory markers, prevented accumulation of lipid and lipoprotein biomarkers, regulated the major receptor regulators of hepatic cholesterol metabolism, as well as normalize lipid distribution in liver and aorta tissue.


Assuntos
Aorta/efeitos dos fármacos , Aterosclerose/prevenção & controle , Poluentes Ambientais/toxicidade , Lipoproteínas LDL/sangue , Nitrilos/toxicidade , Piretrinas/toxicidade , Saponinas/farmacologia , Zygophyllum/química , Animais , Aorta/imunologia , Aorta/metabolismo , Aterosclerose/imunologia , Aterosclerose/metabolismo , Antígenos CD36/metabolismo , Colesterol/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/imunologia , Fígado/metabolismo , Masculino , Folhas de Planta/química , Ratos , Ratos Wistar , Receptores de LDL/metabolismo , Saponinas/isolamento & purificação , Fator de Necrose Tumoral alfa/metabolismo
13.
Chemosphere ; 248: 126075, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32028166

RESUMO

The honeybee, Apis mellifera is economically important for its products (honey, wax, and propolis) and for its role in pollination. This insect is threated due to high population losses in both agriculture and beekeeping. Within causes involved in the loss of honeybees is the increased pesticide use on agriculture. Although current testing for the regularization of insecticide use considers its acute toxic effects on pollinators, little is known about the effects of chronic exposure to sublethal concentrations that may persist in the environment. This study investigated the effect of chronic exposure to sublethal concentrations of lambda-cyhalothrin on the midgut, hypopharyngeal glands, and brain of A. mellifera. Honey bees were fed for eight days with LC50/100 insecticide. Subsequently, the midgut, hypopharyngeal glands, and brain were analyzed in light and transmission electron microscopies. The midgut was not affected after exposure, except in the posterior region with cell fragments in the lumen and changes in the mitochondria. The hypopharyngeal glands were severely affected by the insecticide with changes in the rough endoplasmic reticulum and cell death. The brain has extensive gaps in the neuropil as well as in the cellular bodies, especially in the corpora pedunculata. These resembled cellular alterations similar to those seen in death processes. The results of this study indicate that lambda-cyhalothrin is toxic to bees at sublethal concentrations and ingested chronically, causing damage to the midgut, hypopharyngeal glands, and brain, and may affect physiological and behavioral aspects of these insects.


Assuntos
Abelhas/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Sistema Digestório/efeitos dos fármacos , Hipofaringe/efeitos dos fármacos , Inseticidas/toxicidade , Nitrilos/toxicidade , Piretrinas/toxicidade , Animais , Encéfalo/ultraestrutura , Sistema Digestório/ultraestrutura , Hipofaringe/ultraestrutura , Dose Letal Mediana , Microscopia Eletrônica de Transmissão , Polinização/efeitos dos fármacos
14.
Chemosphere ; 243: 125416, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31995874

RESUMO

Esfenvalerate is a pyrethroid insecticide used widely for agricultural and residential applications. This insecticide has been detected in aquatic environments at concentrations that can induce sub-lethal effects in organisms. In this study, zebrafish embryos were used to examine the effects of environmentally-relevant concentrations of esfenvalerate on development and behavior. It was hypothesized that esfenvalerate exposure would impair locomotion due to its effects on the central nervous system. We also measured mitochondrial bioenergetics and the expression of genes (dopamine system) as putative mechanisms of locomotor impairment. Concentrations of 0.02, 0.2 and 2 µg/L esfenvalerate did not induce significant mortality nor deformity in zebrafish, but there was an acceleration in hatching time for zebrafish exposed to 2 µg/L esfenvalerate. As an indicator of neurotoxicity, the Visual Motor Response (VMR) test was conducted with 5, 6, and 7 dpf zebrafish after continuous exposure, and higher concentrations were used (4 and 8 µg/L esfenvalerate) to better discern age-and dose dependent responses in behavior. Experiments revealed that, unlike the other stages, 6 dpf larvae showed evidence for hypo-activity with esfenvalerate, suggesting that different stages of larval development may show increased sensitivity to pyrethroid exposure. This may be related to age-dependent maturation of the central nervous system. We hypothesized that reduced larval activity may be associated with impaired production of ATP and the function of mitochondria at earlier life stages, however dramatic alterations in oxidative phosphorylation were not observed. Based on evidence that dopamine regulates behavior and studies showing that other pyrethroids affect dopamine system, we measured transcripts involved in dopaminergic signaling. We found that dopamine active transporter was down-regulated with 0.2 µg/L esfenvalerate. Lastly, we comprehensively summarize the current literature (>20 studies) regarding the toxicity of pyrethroids in zebrafish, which is a valuable resource to those studying these pesticides. This study demonstrates that esfenvalerate at environmentally-relevant levels induces hypoactivity that are dependent upon the age of the zebrafish, and these behavioral changes are hypothesized to be related to impaired dopamine signaling.


Assuntos
Comportamento Animal/efeitos dos fármacos , Proteínas da Membrana Plasmática de Transporte de Dopamina/biossíntese , Inseticidas/toxicidade , Locomoção/efeitos dos fármacos , Nitrilos/toxicidade , Piretrinas/toxicidade , Animais , Dopamina/metabolismo , Metabolismo Energético/efeitos dos fármacos , Exposição Ambiental/efeitos adversos , Larva/efeitos dos fármacos , Mitocôndrias/metabolismo , Fosforilação Oxidativa , Estresse Oxidativo/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/embriologia , Peixe-Zebra/metabolismo
15.
Ecotoxicol Environ Saf ; 190: 110119, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31891835

RESUMO

Chlorothalonil is an effective fungicide used in agriculture and formulations of antifouling paints, which use and possible toxicity has been generating great concern. Thus, the present study investigated the effects of chlorothalonil on the antioxidant defense system (ADS) of the mussel Perna perna. The ADS was evaluated in gills and digestive gland after 24 h and 96 h of exposure to environmental relevant levels of chlorothalonil (0.1 and 10 µg/L). The activity of the enzymes superoxide dismutase (SOD), catalase (CAT), glutamate cysteine-ligase (GCL) and glutathione S-transferase (GST), levels of non-enzymatic defenses, represented by glutathione (GSH), and lipoperoxidation (LPO) and protein carbonyls (PCO) were evaluated. Results indicated that exposure to chlorothalonil is affecting the ADS in both tissues. While the activity of SOD increased and GST and GSH were not altered in gills, they decreased in digestive gland after 24 h of exposure to 10 µg/L of chlorothalonil. The contrasting results indicate that gills and digestive gland presented different patterns of responses after exposure to chlorothalonil. Moreover, a tissue-specific response to chlorothalonil was observed. Gills could be acting as the first line of defense, presenting higher enzymatic levels with minor effects on the parameters analyzed. On the other hand, digestive gland, with lower levels of antioxidant defenses, was the most affect organ by chlorothalonil. It also should be highlighted that the fungicide reduced the glutathione metabolism in the digestive gland, which can lead to an imbalance of the redox state within the cells of animals.


Assuntos
Antioxidantes/metabolismo , Fungicidas Industriais/toxicidade , Nitrilos/toxicidade , Perna (Organismo)/fisiologia , Animais , Catalase/metabolismo , Fungicidas Industriais/metabolismo , Brânquias/efeitos dos fármacos , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Glutationa Redutase/metabolismo , Glutationa Transferase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Perna (Organismo)/efeitos dos fármacos , Superóxido Dismutase/metabolismo
17.
Environ Pollut ; 259: 113870, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31918140

RESUMO

Deltamethrin (DLM) is an important member of the pyrethroid pesticide family, and its widespread use has led to serious environmental and health problems. Exposure to DLM causes pathological changes in the liver of animals and humans and can lead to liver fibrosis. However, the mechanism of DLM-induced liver fibrosis remains unclear. Therefore, to address its potential molecular mechanisms, we used both in vivo and in vitro methods. Quails were treated in vivo by intragastric administration of different concentrations of DLM (0, 15, 30, or 45 mg kg-1), and the chicken liver cancer cell line LMH was treated in vitro with various doses of DLM (0, 50, 200, or 800 µg mL-1). We found that DLM treatment in vivo induced liver fibrosis in a dose-dependent manner through the promotion of oxidative stress, activation of transforming growth factor-ß1 (TGF-ß1) and phosphorylation of Smad2/3. Treatment of LMH cells with different concentrations of DLM similarly induced oxidative stress and also decreased cell viability. Collectively, our study demonstrates that DLM-induced liver fibrosis in quails occurs via activation of the TGF-ß1/Smad signaling pathway.


Assuntos
Cirrose Hepática , Nitrilos , Piretrinas , Codorniz , Transdução de Sinais , Proteínas Smad , Fator de Crescimento Transformador beta1 , Animais , Linhagem Celular Tumoral , Galinhas , Cirrose Hepática/induzido quimicamente , Nitrilos/toxicidade , Piretrinas/toxicidade , Transdução de Sinais/efeitos dos fármacos , Proteínas Smad/metabolismo , Fator de Crescimento Transformador beta1/metabolismo
18.
Chemosphere ; 243: 125373, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31765895

RESUMO

The pyrethroid insecticide deltamethrin has been reported to have an effect on vertebrate development and cardiovascular disease. Sodium tanshinone IIA sulfonate (STS) is considered to have cardioprotective effects and melatonin is known to regulate sleep-waking cycles. In this experiment, we used transgenic zebrafish Tg (kdrl:mCherry) and Tg (myl7:GFP) to investigate whether STS and melatonin could reverse the cardiovascular toxicity and neurotoxicity induced by deltamethrin. Zebrafish embryos were exposed to 25 µg/L deltamethrin at 10 hpf and treated with 100 mmol/L STS and 1 µmol/L melatonin showed that deltamethrin treatment affected normal cardiovascular development. In situ hybridization and qRT-PCR results showed that deltamethrin could interfere with the normal expression of cardiovascular development-related genes vegfr2, shh, gata4, nkx2.5, causing functional defects in the cardiovascular system. In addition, deltamethrin could affect the sleep-waking behavior of larvae, increasing the activity of larvae, decreasing the rest behavior and the expression of hcrt, hcrtr, aanat2 were down-regulated. The addition of melatonin and STS can significantly alleviate cardiovascular toxicity and sleep-waking induced by deltamethrin, while restoring the expression of related genes to normal levels. Our study demonstrates the role of STS and melatonin in protecting cardiovascular and sleep-waking behavior caused by deltamethrin.


Assuntos
Sistema Cardiovascular/efeitos dos fármacos , Melatonina/metabolismo , Sistema Nervoso/efeitos dos fármacos , Nitrilos/toxicidade , Praguicidas/toxicidade , Fenantrenos/metabolismo , Piretrinas/toxicidade , Animais , Animais Geneticamente Modificados , Regulação para Baixo , Larva , Orexinas , Peixe-Zebra
19.
Ecotoxicol Environ Saf ; 189: 109917, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31776030

RESUMO

Pollinator populations are in decline worldwide. Multiple factors have been cited as potential causes to these declines. In honey bees, a combination of stressors is known to cause colony losses. Adequate nutrition is a key factor for honey bee growth and colony development. Several studies show that the nutritional quality of the diet is directly proportional to the ability of the bee to face challenges or stressors. We explored the effect of p-coumaric (600 µM) and indole-3-acetic acid (2, 20 or 200 µM) supplementation on the survival and activity of key detoxification enzymes of honey bees exposed to tau-fluvalinate. The dietary supplementation with p-coumaric and indole-3-acetic acids (20 µM) enhanced the survival of bees exposed to tau-fluvalinate (approximately 20%). We also showed that dietary p-coumaric acid increased the levels of cytochrome P450 and glutathione reductase activity in bees treated with tau-fluvalinate, as well as in the untreated controls, while glutathione-S-transferase activity was lower in treated bees than in untreated. In bees fed with indole-3-acetic acid, cytochrome P450 showed increased levels, however, glutathione-S-transferase showed the lowest activity. Moreover, the results showed that supplementation with p-coumaric and indole-3-acetic acids did not alter acetyl cholinesterase activity, nor did treatment with tau-fluvalinate. Altogether, the enzymatic changes related to the detoxification mechanisms observed in bees that were fed with p-coumaric and indole-3-acetic acids could be responsible for the increased survival of bees treated with tau-fluvalinate compared to those that received a control diet. The results presented in this study, together with previous studies, provide evidence of the importance of dietary phytochemicals in the response of honey bees to pesticide exposure. Moreover, these results are the first report of the beneficial effect of the phytohormone indole-3-acetic acid on the survival of honey bees treated with tau-fluvalinate.


Assuntos
Abelhas , Suplementos Nutricionais , Ácidos Indolacéticos , Nitrilos/toxicidade , Praguicidas/toxicidade , Propionatos , Piretrinas/toxicidade , Animais , Sistema Enzimático do Citocromo P-450/metabolismo , Dieta , Inativação Metabólica
20.
Arch Environ Contam Toxicol ; 78(1): 117-123, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31642948

RESUMO

As a commonly used pyrethroid insecticide, deltamethrin is very toxic to honeybees, which seriously threatens the managed and feral honeybee population. Because deltamethrin is a nerve agent, it may interfere with the nervous system of honeybees, such as dance behavior and memory-related characteristics. We found that the waggle dances were less precise in honeybees that consumed syrup containing deltamethrin (pesticide group) than those that consumed normal sucrose syrup (control group). Compared with the control group, honeybees of the pesticide group significantly increased number of circuits per 15 s, the divergence angle, return phases in waggle dances, as well as the crop content of the dance followers. Furthermore, six learning and memory-related genes were significantly interfered with the gene expression levels. Our data suggest that the sublethal dose of deltamethrin impaired the honeybees' learning and memory and resulted in cognitive disorder. The novel results assist in establishing guidelines for the risk assessment of pesticide to honeybee safety and prevention of nontarget biological agriculture pesticide poisoning.


Assuntos
Comunicação Animal , Abelhas/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Inseticidas/toxicidade , Nitrilos/toxicidade , Piretrinas/toxicidade , Animais , Abelhas/fisiologia , Relação Dose-Resposta a Droga , Aprendizagem/efeitos dos fármacos , Memória/efeitos dos fármacos
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