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1.
Insect Sci ; 27(2): 276-291, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30136378

RESUMO

Uridine diphosphate (UDP)-glycosyltransferases (UGTs) are widely distributed within living organisms and share roles in biotransformation of various lipophilic endo- and xenobiotics with activated UDP sugars. In this study, it was found that the activity of UGTs in abamectin-resistant (AbR) strain was significantly higher (2.35-fold) than that in susceptible strain (SS) of Tetranychus cinnabarinus. Further analysis showed that 5-nitrouracil, the inhibitor of UGTs, could enhance the lethal effect of abamectin on mites. From the previous microarray results, we found an UGT gene (UGT201D3) overexpressed in AbR strain. Quantitative PCR analysis showed that UGT201D3 was highly expressed and more inducible with abamectin exposure in the AbR strain. After silencing the transcription of UGT201D3, the activity of UGTs was decreased and the susceptibility to abamectin was increased in AbR strain whereas it was not in SS. Furthermore, UGT201D3 gene was then successfully expressed in Escherichia coli. The recombinant UGT201D3 exhibited α-naphthol activity (2.81 ± 0.43 nmol/mg protein/min), and the enzyme activity could be inhibited by abamectin (inhibitory concentration at 50%: 57.50 ± 3.54 µmol/L). High-performance liquid chromatography analysis demonstrated that the recombinant UGT201D3 could effectively deplete abamectin (15.77% ± 3.72%) incubating with 150 µg protein for 6 h. These results provided direct evidence that UGT201D3 was involved in abamectin resistance in T. cinnabarinus.


Assuntos
Glucuronosiltransferase/metabolismo , Inseticidas , Ivermectina/análogos & derivados , Tetranychidae/metabolismo , Sequência de Aminoácidos , Animais , Escherichia coli , Feminino , Glucuronosiltransferase/genética , Resistência a Inseticidas , Interferência de RNA , Tetranychidae/genética , Uracila/análogos & derivados
2.
Vet Parasitol ; 277: 108992, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31835054

RESUMO

Eprinomectin (EPM) has been recently granted a marketing authorisation in the European Union for use in goats, with a zero-day milk withdrawal period. Considering the high prevalence of benzimidazole resistance worldwide and the economic implications of managing milk residues, EPM may today be considered the main (or even the only) affordable treatment option, at least in dairy goats in the EU. However, the chosen dose (1 mg/kg) seems to be suboptimal, especially for lactating goats, and the chosen route of administration (Pour-on) highly subject to inter-individual variability. Considering the scarcity of anthelmintic resources, such a dosage regimen might threat the sustainability of this crucial drug in goat milk production and needs to be urgently discussed and reassessed.


Assuntos
Indústria de Laticínios/normas , Doenças das Cabras/tratamento farmacológico , Ivermectina/análogos & derivados , Animais , Anti-Helmínticos/administração & dosagem , Indústria de Laticínios/legislação & jurisprudência , Indústria de Laticínios/tendências , União Europeia , Feminino , Cabras , Ivermectina/administração & dosagem
3.
Ecotoxicol Environ Saf ; 188: 109889, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31704331

RESUMO

It is known that abamectin (ABM) inflicts oxidative damage on aquatic animals; however, knowledge about the immune response under pesticide-induced oxidative stress is incomplete. In the present study, several cellular and humoral immune parameters, including total haemocyte counts (THC), lysosomal membrane stability (LMS), activities of acid phosphatase (ACP), alkaline phosphatase (AKP) and lysozyme (LZM) were investigated to reveal the effects of ABM exposure on the immune defence mechanisms of the important freshwater crab, Erocheir sinensis. According to the results, a significant increase of THC was found in low concentration groups (0.03 and 0.06 mg/L), while dramatic decreases occurred in high concentration groups (0.12 and 0.24 mg/L) after 96 h of exposure. We also detected significant increases of reactive oxygen species (ROS) in haemocytes at 0.12 and 0.24 mg/L, and there was a dose- and time-dependent decrease of lysosomal membrane stability. These results suggest that the excessive generation of ROS induced by ABM may be leading the massive collapse of lysosomal membrane, which in turn may be causing the sharp drop of haemocyte counts in E. sinensis. The increase of hydrolytic enzymes ACP and AKP at low concentrations and the decrease at high concentrations also indicate an immune response associated with haemocytes status under stress. However, activities of LZM decreased significantly. After injection of Aeromonas hydrophil, mortalities increased under exposure to ABM and were positively related to ABM concentration. These results confirm that ABM exposure has the ability to impair immune defence and result in the host's susceptibility to pathogens.


Assuntos
Braquiúros/imunologia , Inseticidas/toxicidade , Ivermectina/análogos & derivados , Estresse Oxidativo/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Braquiúros/efeitos dos fármacos , Braquiúros/metabolismo , Hemócitos/efeitos dos fármacos , Hemócitos/metabolismo , Hemócitos/patologia , Imunidade Inata/efeitos dos fármacos , Ivermectina/toxicidade , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Espécies Reativas de Oxigênio/metabolismo
4.
Sci Total Environ ; 701: 134882, 2020 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-31739238

RESUMO

The present work was designed to assess the modulatory effects of sesame oil (SO) and ascorbic acid (AA) on abamectin (ABM)-induced oxidative stress and altered gene expression of hepatic cytochrome P450 2E1 (CYP-2E1), p38 MAPK, and caspase-3 and cerebral P-glycoprotein (Abcb1a receptor). Male rats were distributed into five groups (6 rats/group), receiving distilled water, ABM 2 mg/kg bwt 1/5 LD50 orally for 5 days, ABM + AA 100 mg/kg bwt orally, ABM + SO 5 ml/kg bwt orally, or ABM + SO + AA at the aforementioned doses. Nineteen compounds were identified in the SO sample by GC-MS analysis, including tetradecane,2,6,10-trimethyl, octadecane, 1-hexadecanol,2-methyl, and octadecane,6-methyl. Abamectin significantly upregulated the hepatic CYP-2E1 expression with excess generation of oxidative radicals, as evident by the significant depletion of reduced glutathione and elevation of malondialdehyde concentration (p ≤ 0.05) in rat liver and brain tissues. Further, ABM significantly increased TNF-α concentration, the expression of caspase-3 and p38 MAPK in the liver, as well as p-glycoprotein and GABA-A receptor in the brain. These results were in line with the observed histopathological changes. Sesame oil and/or AA supplementation alleviated ABM-induced cell damage by modulating all tested parameters. In conclusion, ABM induces oxidative stress and increases the expression of CYP-2E1, caspase-3, and p38 MAPK in the liver, as well as P-gp and GABA-A receptor in the brain. These effects could be ameliorated by SO and AA, alone and in combination, probably due to their anti-oxidant, anti-apoptotic, and gene-regulating activities.


Assuntos
Inseticidas/toxicidade , Ivermectina/análogos & derivados , Animais , Ácido Ascórbico , Encéfalo/metabolismo , Expressão Gênica/efeitos dos fármacos , Ivermectina/toxicidade , Fígado , Masculino , Estresse Oxidativo/efeitos dos fármacos , Ratos , Óleo de Gergelim
5.
Malar J ; 18(1): 332, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31564253

RESUMO

BACKGROUND: Misuse of long-lasting insecticidal nets together with resistance of vectors to most of the insecticides for indoor residual spraying and impregnated nets threaten malaria vector control interventions, requiring search for alternative control methods. Reports have shown that Anopheles mosquitoes die when they feed on endectocidal drugs used to treat humans and animals. A study was designed to investigate the efficacy of LongRange™ (eprinomectin 5%) on laboratory reared Anopheles arabiensis fed on treated calves. METHODS: Anopheles arabiensis from insectary colony was fed on three calves treated with therapeutic dose of LongRange™ eprinomectin (1 ml/50 kg) and on non-treated three other calves as control arm. For the feeding, mosquitoes were placed in paper cups covered with nylon cloth mesh and then allowed to feed on the necks of calves. Subsequently, mosquito survival, fecundity, egg hatchability, larval development and adult emergence were recorded. Data were entered and analysed by using SPSS version 20. The Kaplan-Meier survival analysis and independent sample t-test were used. RESULTS: All mosquitoes that fed on LongRange™ Eprinomectin treated calves died within 7 days following blood ingestion. The drug also slightly affected fecundity and hatchability of An. arabiensis. CONCLUSION: Treating livestock with LongRange™ (eprinomectin 5%) may serve as a supplementary control method for zoophagic An. arabiensis.


Assuntos
Anopheles , Inseticidas/administração & dosagem , Ivermectina/análogos & derivados , Controle de Mosquitos/métodos , Animais , Bioensaio , Bovinos , Comportamento Alimentar , Fertilidade , Injeções Subcutâneas , Ivermectina/administração & dosagem , Gado , Malária/transmissão , Mosquitos Vetores
6.
Ecotoxicol Environ Saf ; 183: 109489, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31394379

RESUMO

Avermectins and moxidectin are antiparasitics widely used as active pharmaceutical ingredients in veterinary medicine, as well as in pesticide formulations for pest control in agriculture. Although the use of these compounds provides benefits to agribusiness, they can impact the environment, since a large part of these substances may reach the soil and water from the excreta of treated animals and following direct applications to crops. The present work had the objective of evaluating the dissipation behaviors of abamectin, doramectin, eprinomectin, ivermectin, and moxidectin in four native Brazilian soils of different textural classes (clay, sandy-clay, sandy, and sandy-clay-loam), following OECD Guideline 307. The studies were conducted in a climate chamber at 22 °C, 71% relative humidity, and protected from light. The dissipation studies were carried out with all drugs together, since no difference was verified when studies were done with each drug separately. The concentrations of the drugs in the soils were determined using an ultra-high performance liquid chromatograph coupled to a fluorescence detector or a tandem mass spectrometer. The dissipation half-life (DT50) values ranged from 9 to 16 days and the calculated GUS index values were in the range from -1.10 to 0.08, indicating low mobility of the drugs in the soils evaluated and low tendency for leaching. In addition, a field study was carried out to evaluate the dissipation of abamectin after application of a foliar pesticide in an orange crop. A DT50 of 9 days was determined, which was similar to that obtained under controlled conditions in the climate chamber (12 days), indicating that biotransformation was the primary process influencing the overall dissipation.


Assuntos
Antiparasitários/química , Ivermectina/análogos & derivados , Macrolídeos/metabolismo , Praguicidas/química , Poluentes do Solo/química , Solo/química , Antiparasitários/análise , Brasil , Monitoramento Ambiental , Meia-Vida , Ivermectina/análise , Ivermectina/química , Ivermectina/metabolismo , Macrolídeos/análise , Macrolídeos/química , Praguicidas/análise , Poluentes do Solo/análise
7.
J Agric Food Chem ; 67(36): 9989-9999, 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31430135

RESUMO

Zein's prevalent hydrophobic character is one of the major challenges associated with ineffective utilization as an aqueous nanocarrier for pesticides. Herein, we report an effective approach to hydrophilic modification of zein by phosphorylation using nontoxic sodium tripolyphosphate (STP), thereby improving the water-solubility, foliage wettability, and adhesion ability of zein as a nanocarrier for sustained release of pesticides. The procedure relied on zein grafted with STP via N- and O- phosphate bonds and encapsulation of avermectin (AVM) as a hydrophobic model drug using phosphorylated zein (P-Zein), which achieved pH sensitivity to controlled release of AVM in various applicable environments. The chemical interaction between zein and STP was confirmed by Fourier transform infrared, thermogravimetric analysis, and differential scanning calorimetric. Scanning electron microscopy, dynamic light scattering, and zeta potential technique were applied to investigate their structural characteristics and stability, from which it was found that AVM encapsulated in P-Zein (AVM@P-Zein) formed uniform nanoparticles with average sizes in the range of 174-278 nm under different conditions, and had an excellent stability in aqueous solution. Besides, AVM@P-Zein facilitated the wettability on the foliage surface evidenced from contact angle values owing to the amphiphilic character after phosphorylation as well as enhanced the adhesion ability between liquid and leaf, restricting the pesticide runoff. Ultraviolet-visible spectroscopy was employed to explore the anti-UV property and encapsulation as well as release behavior, which revealed that the presence of P-Zein like a shell protects AVM from UV photolysis with encapsulation efficiency of approximately 81.52%, and the release of AVM from P-Zein showed pH-responsive behavior ascribed to protonation and deprotonation of phosphate under various pH conditions fitting to Elovich kinetic model, achieving the relatively more rapid release under acidic conditions. More importantly, AVM@P-Zein retained the toxicity for insecticidal effect.


Assuntos
Preparações de Ação Retardada/química , Portadores de Fármacos/química , Composição de Medicamentos/métodos , Inseticidas/química , Ivermectina/análogos & derivados , Nanopartículas/química , Zeína/química , Animais , Preparações de Ação Retardada/farmacologia , Portadores de Fármacos/efeitos da radiação , Composição de Medicamentos/instrumentação , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Inseticidas/farmacologia , Ivermectina/química , Ivermectina/farmacologia , Cinética , Mariposas/efeitos dos fármacos , Mariposas/crescimento & desenvolvimento , Nanopartículas/efeitos da radiação , Fosforilação , Polifosfatos/química , Raios Ultravioleta , Zeína/efeitos da radiação
8.
Molecules ; 24(15)2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31374818

RESUMO

Using nanotechnology to develop new formulations of pesticides is considered a possible option in enhancing the efficiency, safety, and photostability of pesticides under various climatic conditions. In the present study, two novel nanoformulations (NFs) were successfully prepared based on nano-delivery systems for emamectin benzoate (EMB) by loading it on cellulose nanocrystals (CNCs) and silicon dioxide nanoparticles (SNPs) as carriers through a freeze-drying method. The synthesized nanoformulations were examined using field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and dynamic light scattering (DLS). The results showed that SNPs and CNCs had a loading efficiency of 43.31% and 15.04% (w/w) for EMB, respectively, and could effectively protect EMB from photolysis under UV radiation. The LC50 values for EMB + SNPs, EMB + CNCs, and EMB commercial formulation against Phenacoccus solenopsis were 0.01, 0.05, and 0.31 µg/mL, respectively, indicating that both NFs were more effective than the EMB commercial formulation. This work seeks to develop new nano-carriers for potential applications of pesticides in plant protection, which will reduce the recommended dose of pesticides and thereby decrease the amount of pesticide residue in food and the environment.


Assuntos
Hemípteros/efeitos dos fármacos , Ivermectina/análogos & derivados , Nanopartículas/química , Animais , Celulose/química , Hemípteros/patogenicidade , Ivermectina/síntese química , Ivermectina/química , Ivermectina/farmacologia , Microscopia Eletrônica de Transmissão , Nanopartículas/ultraestrutura , Controle de Pragas/métodos , Dióxido de Silício/química , Espectroscopia de Infravermelho com Transformada de Fourier
9.
Environ Sci Pollut Res Int ; 26(27): 28309-28318, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31368070

RESUMO

Biological and behavioral responses of the tropical earthworm Perionyx excavatus towards different concentrations of abamectin were evaluated. Abamectin significantly reduced the biomass and reproduction (cocoon production) of P. excavatus as well as inducing histopathological alterations in the cuticle. Biomass loss was recorded in P. excavatus exposed to abamectin at a concentration as low as 0.1 mg active ingredient (a.i.) kg-1, while atrophy, another physiological response, was observed at an abamectin concentration of 0.21 µg cm-2 in a filter paper test. Cocoon production was significantly reduced in the presence of abamectin, and no cocoons were produced at doses of 20 mg a.i. kg-1 or higher, while abamectin at 50 mg a.i. kg-1 induced extreme pathology, characterized by the loss of the integrity of the whole body wall and intestine of P. excavatus. Histopathological alterations can be used as a biomarker to evaluate the toxicological impact of exposure to abamectin.


Assuntos
Ivermectina/análogos & derivados , Oligoquetos/fisiologia , Animais , Biomassa , Filtração , Ivermectina/química , Reprodução
10.
Ecotoxicol Environ Saf ; 183: 109488, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31376804

RESUMO

The extensive application of pesticides in agricultural activities has raised increasing concerns on crop contamination by pesticide residues. Vegetables seem more susceptible to pesticide contamination given the high-intensive application of pesticides during their entire growth, while information about transfer and cell diffusion characteristics of pesticides in vegetables is currently insufficient. Here, we investigated the uptake, translocation and subcellular distribution behaviors of four commonly used pesticides in Chinese cabbage (Brassica rapa var. chinensis) under laboratory hydroponic conditions. Root uptake of pesticides followed the order of fenbuconazole > avermectin > thiamethoxam > spirotetramat. Thiamethoxam was more readily to be translocated from vegetable root to shoot, while spirotetramat, fenbuconazole and avermectin preferentially accumulated in vegetable root. Cell soluble components were the dominant storage compartment for thiamethoxam. The majority of spirotetramat, fenbuconazole and avermectin were partitioned into the cell walls. Hopefully, results of this study would extend the current knowledge of pesticide bioconcentration behavior in food-crops and assist in properly evaluating the threats of pesticide residues to human health via food chain.


Assuntos
Brassica rapa/metabolismo , Praguicidas/metabolismo , Compostos Aza/metabolismo , Transporte Biológico , Humanos , Hidroponia , Ivermectina/análogos & derivados , Ivermectina/metabolismo , Nitrilos/metabolismo , Raízes de Plantas/metabolismo , Compostos de Espiro/metabolismo , Tiametoxam/metabolismo , Triazóis/metabolismo
11.
J Econ Entomol ; 112(6): 2663-2669, 2019 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-31340041

RESUMO

Granules composed of alfalfa and sunflower meal that were impregnated with avermectins (AVMs) were developed for use against the Moroccan locust, Dociostaurus maroccanus (Thunberg). Laboratory experiments with granules containing 0.15% of AVMs fed to locust nymphs resulted in 100% death within 5 d. The quantification of AVM loss after exposure of AVM-containing preparative forms to UV light for various time periods was performed using high-performance liquid chromatography (HPLC). The results showed no loss of AVMs from the granules after 3 h of their exposure to UV light. The effect of UV radiation on a thin layer of the AVM solution led to the rapid degradation of AVMs. Only 0.2% of the initial AVM amount was detected after 3 h of exposure. In the granulated form, the AVM content remained stable for 10 mo when stored at room temperature in the dark. A method combining solid-phase extraction with HPLC was developed for the quantification of AVMs in locust nymphs. The granulated AVMs are characterized by their high resistance to UVB radiation. The use of plant-based granules impregnated with AVMs can be considered a very promising tool for locust control.


Assuntos
Gafanhotos , Animais , Cromatografia Líquida de Alta Pressão , Ivermectina/análogos & derivados , Ninfa
12.
Nat Commun ; 10(1): 3206, 2019 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-31324795

RESUMO

Diosgenin is a spiroketal steroidal natural product extracted from plants and used as the single most important precursor for the world steroid hormone industry. The sporadic occurrences of diosgenin in distantly related plants imply possible independent biosynthetic origins. The characteristic 5,6-spiroketal moiety in diosgenin is reminiscent of the spiroketal moiety present in anthelmintic avermectins isolated from actinomycete bacteria. How plants gained the ability to biosynthesize spiroketal natural products is unknown. Here, we report the diosgenin-biosynthetic pathways in himalayan paris (Paris polyphylla), a monocot medicinal plant with hemostatic and antibacterial properties, and fenugreek (Trigonella foenum-graecum), an eudicot culinary herb plant commonly used as a galactagogue. Both plants have independently recruited pairs of cytochromes P450 that catalyze oxidative 5,6-spiroketalization of cholesterol to produce diosgenin, with evolutionary progenitors traced to conserved phytohormone metabolism. This study paves the way for engineering the production of diosgenin and derived analogs in heterologous hosts.


Assuntos
Vias Biossintéticas , Sistema Enzimático do Citocromo P-450/metabolismo , Diosgenina/metabolismo , Furanos/metabolismo , Lipogênese/fisiologia , Compostos de Espiro/metabolismo , Antibacterianos , Colesterol/metabolismo , Citocromos/metabolismo , Galactagogos , Perfilação da Expressão Gênica , Ivermectina/análogos & derivados , Melanthiaceae/química , Metabolômica , Reguladores de Crescimento de Planta/metabolismo , Trigonella
13.
J Fish Dis ; 42(10): 1351-1357, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31309582

RESUMO

Pseudocapillaria tomentosa is a pathogenic nematode parasite, causing emaciation and severe inflammatory lesions in the intestines in zebrafish Danio rerio (Hamilton 1822). Emamectin benzoate is commercially available analogue of ivermectin used for treating salmon for sea lice, under the brand name SLICE® , and we have used this for treating zebrafish with the P. tomentosa. Here, SLICE® , 0.2 per cent active emamectin benzoate, was used for oral treatments at 0.35 mg emamectin benzoate/kg fish/day for 14 days starting at 7 days post-exposure (dpe). Another experiment entailed initiating treatment during clinical disease (starting at 28 dpe). Early treatment was very effective, but delaying treatment was less so, presumably due to inappetence in clinically affected fish. We evaluated emamectin benzoate delivered in water, using Lice-Solve™ (mectinsol; 1.4% active emamectin benzoate) in two experiments. Application of four 24-hr treatments, space over 7 days was initiated at 28 dpe at either 0.168 or 0.56 mg emamectin benzoate/L/bath, and both treatments completely eradicated infections. This was 3 or 10 times manufacture's recommended dose, but was not associated with clinical or histological side effects.


Assuntos
Antinematódeos/farmacologia , Infecções por Enoplida/veterinária , Enoplídios/efeitos dos fármacos , Doenças dos Peixes/tratamento farmacológico , Ivermectina/análogos & derivados , Peixe-Zebra , Animais , Relação Dose-Resposta a Droga , Infecções por Enoplida/tratamento farmacológico , Feminino , Ivermectina/farmacologia , Masculino
14.
Molecules ; 24(13)2019 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-31269660

RESUMO

Pesticides vary in the level of poisonousness, while a conventional rapid test card only provides a general "absence or not" solution, which cannot identify the various genera of pesticides. In order to solve this problem, we proposed a seven-layer paper-based microfluidic chip, integrating the enzyme acetylcholinesterase (AChE) and chromogenic reaction. It enables on-chip pesticide identification via a reflected light intensity spectrum in time-sequence according to the different reaction efficiencies of pesticide molecules and assures the optimum temperature for enzyme activity. After pretreatment of figures of reflected light intensity during the 15 min period, the figures mainly focused on the reflected light variations aroused by the enzyme inhibition assay, and thus, the linear discriminant analysis showed satisfying discrimination of imidacloprid (Y = -1.6525X - 139.7500), phorate (Y = -3.9689X - 483.0526), and avermectin (Y = -2.3617X - 28.3082). The correlation coefficients for these linearity curves were 0.9635, 0.8093, and 0.9094, respectively, with a 95% limit of agreement. Then, the avermectin class chemicals and real-world samples (i.e., lettuce and rice) were tested, which all showed feasible graphic results to distinguish all the chemicals. Therefore, it is feasible to distinguish the three tested kinds of pesticides by the changes in the reflected light spectrum in each min (15 min) via the proposed chip with a high level of automation and integration.


Assuntos
Inibidores Enzimáticos/análise , Dispositivos Lab-On-A-Chip , Óptica e Fotônica/métodos , Papel , Resíduos de Praguicidas/análise , Análise por Conglomerados , Ivermectina/análogos & derivados , Ivermectina/análise , Ivermectina/química , Neonicotinoides/análise , Neonicotinoides/química , Nitrocompostos/análise , Nitrocompostos/química , Forato/análise , Forato/química , Fatores de Tempo
15.
J Econ Entomol ; 112(4): 1858-1865, 2019 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-31329893

RESUMO

Tetranychus cinnabarinus (Boisduval), i.e., carmine spider mite, is a worldwide pest that can cause serious damage to plants. Problems of resistance have arisen since abamectin usage in the control of T. cinnabarinus. Unfortunately, there are only limited data on the extent of this problem. To understand the development of abamectin resistance in the carmine spider mite, we prokaryotically expressed an intradiol ring-cleavage dioxygenase (ID-RCD) gene sequence, TcID-RCD1, which had a significant upregulated expression of over 7.7 times in an abamectin-resistant strain (AbR) when compared with that of a susceptible strain (SS). The crude enzyme activity also indicated that the AbR had a higher activity than that exhibited in SS. When susceptible individuals were treated with abamectin, TcID-RCD1 was also overexpressed. Furthermore, using the RNA interference (RNAi) technique, TcID-RCD1 was successfully knocked down, with the expression level decreasing significantly to approximately 39% in the SS strain compared with the control. And the mortality of mites feeding on dsTcID-RCD1 increased significantly when treated with abamectin. These results strongly suggest that TcID-RCD1 is involved in abamectin resistance in T. cinnabarinus.


Assuntos
Acaricidas , Dioxigenases , Ácaros , Tetranychidae , Animais , Ivermectina/análogos & derivados
16.
Vet Parasitol ; 270 Suppl 1: S58-S63, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31182302

RESUMO

The efficacy of three consecutive monthly treatments with a novel topical product (Revolution® Plus/Stronghold® Plus, Zoetis) containing selamectin in combination with the isoxazoline, sarolaner, was compared with that of another topical isoxazoline, fluralaner [Bravecto® (fluralaner topical solution) for Cats, Merck] against Ixodes scapularis ticks on cats. Twenty-four cats were ranked by pre-treatment tick counts to form groups of three and were randomly allocated to be treated with placebo, the minimum label dosage of Revolution® Plus (6 mg/kg selamectin plus 1 mg/kg sarolaner) or the minimum label dosage of Bravecto® for Cats (40 mg/kg fluralaner) within the groups. On Days 0, 30, and 60, each cat in the placebo and Revolution® Plus-treated groups was treated topically, whereas cats in the Bravecto® for Cats-treated group were treated topically once on Day 0 with fluralaner and, subsequently, these animals were treated with the placebo on Days 30 and 60 to maintain masking. Doses were calculated based on weight to provide the minimum label dosage for each product; the calculated volume of product to be administered was rounded off to the nearest 0.1 mL. The selamectin plus sarolaner-treated cats received effective dosages of 5.29-7.12 mg/kg selamectin and 0.88-1.19 mg/kg sarolaner, while the fluralaner cats received dosages of 35.21-43.16 mg/kg fluralaner. Cats were infested with approximately 50 unfed viable adult I. scapularis ticks on Days 5, 12, 26, 40, 54, 68, 82, and 88. Efficacy was assessed at 48 h after each infestation. There were no adverse reactions to any treatment during the study. The placebo-treated cats maintained adequate tick infestations throughout the study. Three monthly treatments with selamectin plus sarolaner (Revolution® Plus) resulted in high and consistent efficacy against I. scapularis for up to 30 days after each treatment. Based on geometric means, efficacy was ≥99.1% at all time points assessed. Treatment with fluralaner (Bravecto® for Cats) provided high and consistent efficacy of ≥99.3% up to Day 70. On Day 84, efficacy was 90.1%; however, cats from which ticks were recovered on Day 84 had received approximately 4%-12% less than the minimum dosage of 40 mg/kg fluralaner. Three consecutive monthly treatments with Revolution® Plus or a single treatment with Bravecto® for Cats provided >90% control of I. scapularis ticks over a 12-week time period.


Assuntos
Antiparasitários/administração & dosagem , Azetidinas/administração & dosagem , Doenças do Gato/tratamento farmacológico , Isoxazóis/administração & dosagem , Ivermectina/análogos & derivados , Compostos de Espiro/administração & dosagem , Controle de Ácaros e Carrapatos , Infestações por Carrapato/veterinária , Administração Tópica , Animais , Gatos , Composição de Medicamentos/veterinária , Feminino , Ivermectina/administração & dosagem , Ixodes/efeitos dos fármacos , Masculino , Infestações por Carrapato/tratamento farmacológico , Resultado do Tratamento
17.
Chemosphere ; 234: 328-337, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31229705

RESUMO

The widespread use of abamectin has recently raised safety concerns as abamectin has yielded various toxicities to non-target organisms. However, the underlying mechanisms of abamectin-induced toxicity are still largely unknown. The present study aimed to investigate the abamectin-induced cytotoxicity in mouse macrophage cells (RAW264.7) and its underlying mechanisms. Abamectin treatment caused oxidative stress as characterized by increased intensity of the ROS indicator. Abamectin also led to DNA damage as demonstrated by increased 8-OHdG/dG ratio in cells even at a relatively low dose (NOAEL). Pretreatment with catalase-PEG, a ROS inhibitor, attenuated abamectin-induced DNA damage, indicating that ROS overproduction should be the reason for abamectin-induced DNA damage. The effects of abamectin on ROS elimination and generation were also investigated, and the results showed that abamectin induced concentration-dependent alteration in the expression and activities of CAT, SOD, GPx enzymes and GSH level (ROS elimination), but had limited effects on the expression and activities of NOX, mitochondrial complex I and III (ROS production) in RAW264.7 cells. Therefore, the effects of abamectin on ROS elimination should be the main reason for abamectin-induced oxidative stress in RAW264.7 cells. Abamectin treatment activated MAPK and ATM/ATR signaling pathways as demonstrated by increased phosphorylation of JNK, ATM and ATR. In addition, inhibiting JNK and ATM/ATR signaling pathways partially rescued the decrease in cell viability, indicating that abamectin-induced ROS overproduction and DNA damage might finally lead to cytotoxicity through JNK and ATM/ATR signaling pathways. These findings should be useful for the more comprehensive assessment of the toxic effects of abamectin.


Assuntos
Dano ao DNA , Ivermectina/análogos & derivados , Macrófagos/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Animais , Sobrevivência Celular/efeitos dos fármacos , Inseticidas/toxicidade , Ivermectina/toxicidade , Macrófagos/metabolismo , Camundongos , Estresse Oxidativo/efeitos dos fármacos , Fosforilação , Células RAW 264.7 , Transdução de Sinais/efeitos dos fármacos
18.
Exp Appl Acarol ; 78(3): 343-360, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31250237

RESUMO

Tetranychus urticae Koch is one of the most common and harmful pests in vegetable production areas. Similar to other countries, control of T. urticae is mainly based on acaricides in Turkey. However, T. urticae rapidly develops resistance and failures in chemical control have occurred frequently. The toxicity of various acaricides was investigated in ten T. urticae populations collected from vegetable crops in Turkey. In addition, populations were screened for the presence of currently known target-site resistance mutations. It was shown that resistance to bifenthrin was the most widespread, but also half of the populations were resistant to abamectin and hexythiazox. Resistance mutations in the voltage-gated sodium channel (VGSC) and chitin synthase 1 were found in various populations. Moreover, for the first time, F1538I and L1024V VGSC mutations were reported for Turkish populations. Mutations that confer resistance to abamectin, bifenazate and METI-I acaricides such as pyridaben were not detected. These results will contribute to the design of an effective resistance management program in Turkey.


Assuntos
Acaricidas/farmacologia , Resistência a Medicamentos/genética , Ivermectina/análogos & derivados , Piretrinas/farmacologia , Tetranychidae/efeitos dos fármacos , Tiazolidinas/farmacologia , Animais , Produtos Agrícolas/crescimento & desenvolvimento , Cadeia Alimentar , Ivermectina/farmacologia , Mutação , Tetranychidae/genética , Turquia , Verduras/crescimento & desenvolvimento
19.
Environ Sci Pollut Res Int ; 26(24): 25107-25116, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31254196

RESUMO

The overdosage use of pesticide was harmful to the environment and human health, which was mainly caused by the low utilization rate of the pesticide. However, the pesticide microcapsule with sustained-release and stimulating response properties could effectively solve this problem. Preparation of carboxymethyl cellulose grafting dimethyldiallylammonium chloride (CMC-g-PDMDAAC) through grafting polymerization and trapping as well as encapsulation of avermectin (AVM) via electrostatic interactions resulted in the formation of AVM/CMC-g-PDMDAAC microcapsules. The results showed that the particle size was 200~300 nm. The encapsulation efficiency was as high as 72.06%. Furthermore, the remaining rate of encapsulated AVM increased from 50.0 to 81.60% after UV irradiation for 359 min. The microcapsules exhibited significant enzyme and pH stimuli responsiveness. Finally, CMC-g-PDMDAAC had no significant difference effect on the toxicity of AVM, AVM could be found, and DMDAAC featured a synergistic effect on the toxicological effects of AVM. Graphical abstract.


Assuntos
Carboximetilcelulose Sódica/química , Ivermectina/análogos & derivados , Praguicidas/química , Polietilenos/química , Compostos de Amônio Quaternário/química , Cápsulas/química , Concentração de Íons de Hidrogênio , Ivermectina/química , Tamanho da Partícula , Polimerização , Raios Ultravioleta
20.
Vet Parasitol ; 270 Suppl 1: S38-S44, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31104940

RESUMO

The efficacy and safety of a new topical formulation containing selamectin plus sarolaner (Revolution® Plus / Stronghold® Plus, Zoetis) was evaluated for the prevention of heartworm (Dirofilaria immitis) disease and the treatment of roundworm infection in cats enrolled as veterinary patients in two field studies conducted in Japan. In the heartworm field study, 91 cats negative for D. immitis antigen and anti-D. immitis antibody were enrolled and received 9 monthly topical treatments with selamectin plus sarolaner during the period of April to December 2015. Efficacy was assessed by testing post-treatment blood samples collected 8, 12, and 15 months after initiation of treatment for the presence of D. immitis antigen and anti-D. immitis antibody. Eighty-seven cats completed the entire study and were included in the determination of efficacy. No D. immitis antigen or anti-D. immitis antibody were detected in any of the post-treatment samples. In the roundworm field study, completed in the period from April to November 2015, 64 cats with ≥100 roundworm eggs per gram (EPG) of feces were enrolled and allocated randomly in a 1:1 ratio, to receive either selamectin plus sarolaner or emodepside plus praziquantel (Profender®, Bayer). Treatments were administered topically on Days 0 and 30, and efficacy was assessed by fecal EPG counts conducted on Days 14, 30, and 60. All cats completed the entire study. At enrollment, all cats were infected with Toxocara cati. Compared to pre-treatment, geometric mean T. cati EPG counts on Days 14, 30, and 60 were reduced by >99.9% in both treatment groups. There were no treatment-related adverse events in either study. Monthly topical administration of Revolution® Plus / Stronghold® Plus providing a minimum of 6 mg/kg selamectin and 1 mg/kg sarolaner was safe and effective in the prevention of heartworm disease and the treatment of roundworm infection in cats enrolled as veterinary patients in Japan.


Assuntos
Antiparasitários/administração & dosagem , Azetidinas/administração & dosagem , Doenças do Gato/prevenção & controle , Dirofilariose/prevenção & controle , Enteropatias Parasitárias/veterinária , Ivermectina/análogos & derivados , Infecções por Nematoides/veterinária , Compostos de Espiro/administração & dosagem , Administração Tópica , Animais , Doenças do Gato/tratamento farmacológico , Doenças do Gato/parasitologia , Gatos , Dirofilaria immitis/efeitos dos fármacos , Dirofilaria immitis/imunologia , Dirofilariose/tratamento farmacológico , Dirofilariose/parasitologia , Composição de Medicamentos/veterinária , Feminino , Helmintíase/tratamento farmacológico , Helmintíase/parasitologia , Helmintíase/prevenção & controle , Enteropatias Parasitárias/tratamento farmacológico , Enteropatias Parasitárias/parasitologia , Enteropatias Parasitárias/prevenção & controle , Ivermectina/administração & dosagem , Masculino , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/parasitologia , Infecções por Nematoides/prevenção & controle , Contagem de Ovos de Parasitas/veterinária , Distribuição Aleatória , Toxocara/efeitos dos fármacos , Resultado do Tratamento
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