Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 10.585
Filtrar
1.
Chemosphere ; 287(Pt 2): 132089, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34509765

RESUMO

Plant essential oil-based insecticides, with special reference to those that may be obtained from largely available biomasses, represent a valuable tool for Integrated Pest Management. However, the sublethal effects and the potential effects on aggressive insect traits of these green insecticides are understudied. Herein, the lethal and sub-lethal effects of the carlina oxide, constituting more than 97% of the whole Carlina acaulis (Asteraceae) root essential oil (EO), were determined against an invasive polyphagous tephritid pest, Ceratitis capitata (medfly). The carlina oxide was formulated in a mucilaginous solution containing carboxymethylcellulose sodium salt, sucrose, and hydrolysed proteins, showing high ingestion toxicity on medfly adults. The behavioural effects of carlina oxide at LC10 and LC30 were evaluated on the medfly aggressive traits, which are crucial for securing reproductive success in both sexes. Insecticide exposure affected the directionality of aggressive actions, but not the aggression escalation intensity and duration. The EO safety to mammals was investigated by studying its acute toxicity on the stomach, liver, and kidney of rats after oral administration. Only the highest dose (1000 mg/kg) of the EO caused modest neurological signs and moderate effects on the stomach, liver, and kidney. The other doses, which are closer to the practical use of the EO when formulated in protein baits, did not cause side effects. Overall, C. acaulis-based products are effective and safe to non-target mammals, deserving further consideration for eco-friendly pesticide formulations.


Assuntos
Asteraceae , Ceratitis capitata , Inseticidas , Óleos Voláteis , Animais , Inseticidas/toxicidade , Mamíferos , Óleos Voláteis/toxicidade , Ratos
2.
Environ Pollut ; 292(Pt A): 118212, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34582921

RESUMO

Varroa mite is one of the major adverse factors causing honey bee population decline. In this study, Varroa destructor-infested and uninfested honey bee colonies were established by selective applying miticide (Apivar® amitraz). Mite population was monitored monthly (April-October 2016), and deformed wing virus (DWV) loading was detected seasonally (April, July, and October). Four immunity- and two physiology-related gene expressions, natural mortality, and susceptibility to five insecticides were comparatively and seasonally examined in field-collected honey bee workers. Results showed that Apivar-treated bee colonies had minor or undetectable mite and DWV (using RT-qPCR) infestations in whole bee season, while untreated colonies had substantially higher mite and DWV infestations. In untreated colonies, Varroa mite population irregularly fluctuated over the bee season with higher mite counts in Jun (318 ± 89 mites dropped in 48 h) or August (302) than that (25 ± 4 or 34) in October, and mite population density was not dynamically or closely correlated with the seasonal shift of honey bee natural mortality (regression slope = -0.5212). Unlike mite, DWV titer in untreated colonies progressively increased over the bee season, and it was highly correlated (R2 = 1) with the seasonal increase of honey bee natural mortality. Significantly lower gene expressions of dor, PPO, mfe, potentially PPOa and eat as well, in untreated colonies also indicated an association of increased DWV infestation with decreased physiological and immunity-related functions in late-season honey bees. Furthermore, bees with lower mite/DWV infestations exhibited generally consistently lower susceptibilities (contact and oral toxicities) to five representative insecticides than the bees without Apivar treatment. All of these data from this study consistently indicated an interaction of Varroa/viral infestations with insecticide susceptibilities in honey bees, potentially through impairing bee's physiology and immunity, emphasizing the importance of mite control in order to minimize honey bee decline.


Assuntos
Acaricidas , Inseticidas , Vírus de RNA , Varroidae , Acaricidas/toxicidade , Animais , Abelhas , Inseticidas/toxicidade
3.
Environ Pollut ; 292(Pt A): 118317, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34634407

RESUMO

Neonicotinoids have been often detected in aquatic environment with high concentrations; however, little is known about their risk and fate to/in fish. This study systematically investigated the bio-uptake, tissue distribution and metabolism of neonicotinoids in zebrafish, taking clothianidin (CLO) as an example. The results revealed the uptake and elimination kinetics of CLO in whole fish and different tissues was very similar, and its bioconcentration factor (<1) indicates the low bioaccumulation potential in zebrafish. The highest accumulative tissues for CLO were found to be intestine and liver. Eight biotransformation products were identified in intestine and liver, and the metabolic pathways were found to be N-demethylation and nitro-reduction. The metabolic kinetics of two products (desmethyl clothianidin and clothianidin urea) revealed the metabolism of CLO mainly occurred in liver and intestine. This suggested that the hepatobiliary system played an important role in the metabolism and elimination of CLO. This study provides a comprehensive evaluation of the toxicokinetics of CLO in zebrafish, and these results can contribute to its ecological risk assessment.


Assuntos
Inseticidas , Animais , Guanidinas/toxicidade , Inseticidas/toxicidade , Neonicotinoides/toxicidade , Tiazóis , Distribuição Tecidual , Peixe-Zebra
4.
Environ Pollut ; 292(Pt A): 118335, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34637835

RESUMO

Sown seeds are a key component of many farmland birds' diets due to natural food shortages in autumn and winter. Because these seeds are often treated with pesticides, their ingestion by birds can result in toxic effects. For risk assessment, data on treated seed toxicity should be combined with information about exposure risk for wild birds and the factors that modulate it. We characterized the exposure of red-legged partridges to pesticide-treated seeds through the analysis of digestive contents of birds shot by hunters (n = 194) in an agricultural region in central Spain. We measured the contribution of sown seeds to the partridges' diet and how it related to pesticide exposure. Moreover, we evaluated the influence of landscape composition on the intake of sown seeds and pesticides by partridges. During peak sowing time, seeds constituted half (50.7%) of the fresh biomass ingested by partridges, which consumed mostly winter cereal seeds (42.3% of biomass). Residues of seven fungicides and one insecticide (active ingredients) were detected in 33.0% of birds. The presence of pesticides in digestive contents was linked to the ingestion of cereal sown seeds. Moreover, dietary exposure of birds to pesticides was modulated by landscape characteristics, being lower in areas with heterogeneous landscapes, greater habitat mosaic and more natural vegetation. The estimated dietary intake of pesticides resulting from our field observations, in combination with experimental data on pesticide toxicity, raise concerns about the risks that pesticide-treated cereal seeds pose to granivorous bird populations. Our results highlight the importance of farming landscape composition and diversification, which should be considered as a priority in the agricultural policy to mitigate pesticide risks to farmland birds through the consumption of treated seeds.


Assuntos
Fungicidas Industriais , Galliformes , Inseticidas , Animais , Fungicidas Industriais/toxicidade , Inseticidas/análise , Inseticidas/toxicidade , Sementes/química , Espanha
5.
Sci Total Environ ; 803: 150026, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-34500277

RESUMO

Pesticides are extensively used to control pests, diseases, and weeds in order to increase agricultural production. Usage of indiscriminate doses and persistent pesticides has not only caused resistance issues in insect pests but has also had deleterious effects on non-target organisms (beneficial insects, fish, and wildlife) and caused environmental contamination (soil, water, and air) through leaching, overflow, and insecticide spray drift. Exposure from eating food and drinking water contaminated to pesticide residues is also affecting human health. This study was conducted to obtain information to reduce pesticide resistance and environmental pollution. A cotton dusky bug (Oxycarenus hyalinipennis) population was collected from a farmer's field and exposed to fipronil for 18 generations. In comparison to an unselected strain (XYZ-FS) and a field population (Field-Popn), the fipronil-selected strain of O. hyalinipennis (XYZ-FR) developed a 2631.50-fold level of resistance and a 202.42-fold resistance level respectively. Significantly higher fecundity was observed in the XYZ-FS (24.93) compared to that of Hybrid2 (XYZ-FR ♀ XYZ-FS ♂) (17.60), Hybrid1 (XYZ-FR ♂ × XYZ-FS ♀) (17.13), and XYZ-FR (12.6). The intrinsic rate of natural increase, relative fitness and biotic potential were highest in XYZ-FS, followed by Hybrid2, Hybrid1, and XYZ-FR. The XYZ-FR strain of O. hyalinipennis had very low cross-resistance to profenofos (1.15-2.83-fold), and emamectin benzoate (1.09-2.86-fold) and moderate resistance to bifenthrin (5.49-24.54-fold) when selection progressed from G4 to G19. The proper use of this pesticide, along with rotation and a high-dose strategy may helpful to reduce the risk of resistance development and also its negative impacts on the environment and humans.


Assuntos
Heterópteros , Inseticidas , Animais , Humanos , Resistência a Inseticidas , Inseticidas/toxicidade , Pirazóis , Medição de Risco
6.
Sci Total Environ ; 804: 150254, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34798758

RESUMO

Although the toxicity of neonicotinoid insecticides has been demonstrated in several studies, the information on metabolism, behavior, and health risk remains limited and has raised concerns about its potential toxicity. Thus, in this study we assessed the effects of nitenpyram using different sublethal concentrations (one-third and one-tenth of the acute LC50 values) on various developmental and metabolic parameters from gene expression regulation in Drosophila melanogaster (model system used worldwide in ecotoxicological studies). As a result, nitenpyram sublethal concentrations prolonged the developmental time for both pupation and eclosion. Additionally, nitenpyram sublethal concentrations significantly decreased the lifespan, pupation rate, eclosion rate, and production of eggs of D. melanogaster. Moreover, the mRNA expression of genes relevant for development and metabolism was significantly elevated after exposure. Mixed function oxidase enzymes (Cyp12d1), (Cyp9f2), and (Cyp4ae1), hemocyte proliferation (RyR), and immune response (IM4) genes were upregulated, whereas lifespan (Atg7), male mating behavior (Ple), female fertility (Ddc), and lipid metabolism (Sxe2) genes were downregulated. These findings support a solid basis for further research to determine the hazardous effects of nitenpyram on health and the environment.


Assuntos
Proteínas de Drosophila , Drosophilidae , Inseticidas , Praguicidas , Animais , Proteína 7 Relacionada à Autofagia , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Drosophilidae/metabolismo , Feminino , Inseticidas/toxicidade , Masculino , Neonicotinoides , Reprodução , Transcriptoma
7.
Biol Trace Elem Res ; 200(1): 228-237, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33566284

RESUMO

Organophosphate compounds are the most widely employed insecticides in countries with high agriculture activity. On average, organophosphates cause 3 million people to poison and 200 000 deaths per year due to food chain or occupational, accidental, or suicidal exposure. Our study aimed to research selenium's protective role against the toxic action of CPF, one of the most commonly used organophosphates, with an experimental model formed with rats. A total of 56 male SD rats were distributed into seven groups as follows: control (tap water), sham (corn oil), group I (5.4 mg/kg CPF), group II (13.5 mg/kg CPF), group III (3 mg/kg Se), group IV (5.4 mg/kg CPF+Se), and group V (13.5 mg/kg CPF+Se). Following 6 weeks of oral exposure, there were significant changes in AChE activity, biochemical and hematological parameters, and trace element levels in CPF-treated rats. In the high-dose CPF group, RBC values, Hb, and Hct decreased, and values of WBC, AST, ALT, ALP increased (p < 0.001) significantly compared to control, sham, and Se groups. While there was no significant change in zinc level, the copper and selenium levels were significantly higher in group IV than in control (p < 0.001) and sham (p < 0.05, p < 0.01, respectively) groups. Moreover, max. O.R.L. was found statistically more elevated in the high-dose CPF group compared to control, sham, and Se groups (p < 0.05, p < 0.05, and p < 0.01, respectively). All results indicated that Se is an antioxidant that reduces the toxic effects caused by CPF. Employing combinations of chlorpyrifos and selenium appeared greatly in restoring the harmful effects of CPF exposure.


Assuntos
Clorpirifos , Inseticidas , Selênio , Oligoelementos , Animais , Clorpirifos/toxicidade , Inseticidas/toxicidade , Masculino , Ratos , Ratos Sprague-Dawley , Selênio/farmacologia
8.
Chemosphere ; 286(Pt 1): 131642, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34351280

RESUMO

Neonicotinoids are replacement insecticides increasingly used for organophosphates, methylcarbamates, and pyrethroids. Experimental evidence suggests neonicotinoids may affect glucose metabolism and insulin secretion through pancreatic ß cell dysfunction, oxidative stress, and inflammation. However, no epidemiologic study has investigated neonicotinoids as potential diabetogens. We examined associations between neonicotinoids with insulin and glucose homeostasis parameters among 1381 non-diabetic adults in the National Health and Nutrition Examination Survey (2015-2016). Urinary concentrations of acetamiprid, clothianidin, imidacloprid, N-desmethyl-acetamiprid, and 5-hydroxy-imidacloprid were quantified. Fasting plasma glucose, insulin, and hemoglobin A1c (HbA1c) were assessed. Insulin resistance was defined as a homeostatic model assessment of insulin resistance ≥2.5. We used weighted linear and logistic regression to estimate associations between detectable neonicotinoids with insulin and glucose homeostasis parameters compared to non-detectable neonicotinoid concentrations. Weighted detection frequencies for imidacloprid, 5-hydroxy-imidacloprid, and N-desmethyl-acetamiprid were 4.4 %, 21.5 %, and 32.8 %, respectively. Detectable imidacloprid (ß = -4.7 µIU/mL, 95 % confidence interval [CI] -8.5, -0.8) and 5-hydroxy-imidacloprid (ß = -2.4 µIU/mL, 95 % CI -4.6, -0.2) were associated with lower fasting plasma insulin levels. Individuals with detectable 5-hydroxy-imidacloprid had lower odds of insulin resistance (odds ratio [OR] = 0.3, 95 % CI 0.2, 0.7). We observed evidence of sexually dimorphic associations between N-desmethyl-acetamiprid with glucose (pint = 0.079) and 5-hydroxy-imidacloprid with HbA1c (pint = 0.038), with patterns suggesting positive associations in males and negative associations in females. Associations between 5-hydroxy-imidacloprid and insulin were modified by body mass index (BMI) (pint = 0.013). We additionally observed age modified associations between 5-hydyroxy-imidacloprid and glucose (pint = 0.048). Results suggest neonicotinoids may be associated with insulin and glucose homeostasis indices and call for prospective studies to examine the metabolic impact of these replacement insecticides in humans.


Assuntos
Inseticidas , Insulina , Adulto , Feminino , Glucose , Homeostase , Humanos , Inseticidas/toxicidade , Masculino , Neonicotinoides , Nitrocompostos , Inquéritos Nutricionais , Estudos Prospectivos
9.
Sci Total Environ ; 805: 150351, 2022 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-34818794

RESUMO

Pesticide risk-assessment guidelines for honeybees (Apis mellifera) generally require determining the acute toxicity of a chemical over the short-term through fix-duration tests. However, potential long-lasting or delayed effects resulting from an acute exposure (e.g. a single dose) are often overlooked, although the modification of a developmental process may have life-long consequences. To investigate this question, we exposed young honeybee workers to a single sublethal field-realistic dose of a neurotoxic pesticide, sulfoxaflor, at one of two amounts (16 or 60 ng), at the moment when they initiated orientation flights (preceding foraging activity). We then tracked in the field their flight activity and lifespan with automated life-long monitoring devices. Both amounts of sulfoxaflor administered reduced the total number of flights but did not affect bee survival and flight duration. When looking at the time series of flight activity, effects were not immediate but delayed until foraging activity with a decrease in the daily number of foraging flights and consequently in their total number (24 and 33% less for the 16 and 60 ng doses, respectively). The results of our study therefore blur the general assumption in honeybee toxicology that acute exposure results in immediate and rapid effects and call for long-term recording and/or time-to-effect measurements, even upon exposure to a single dose of pesticide.


Assuntos
Inseticidas , Praguicidas , Animais , Abelhas , Inseticidas/toxicidade , Praguicidas/toxicidade , Piridinas , Compostos de Enxofre
10.
Pestic Biochem Physiol ; 179: 104965, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34802515

RESUMO

The fall armyworm (FAW), Spodoptera frugiperda, is a global pest of multiple economically important row crops and the development of resistance to commercially available insecticidal classes has inhibited FAW control. Thus, there is a need to identify chemical scaffolds that can provide inspiration for the development of novel insecticides for FAW management. This study aimed to assess the sensitivity of central neurons and susceptibility of FAW to chloride channel modulators to establish a platform for repurposing existing insecticides or designing new chemicals capable of controlling FAW. Potency of select chloride channel modulators were initially studied against FAW central neuron firing rate and rank order of potency was determined to be fipronil > lindane > Z-stilbene > DIDS > GABA > E-stilbene. Toxicity bioassays identified fipronil and lindane as the two most toxic modulators studied with topical LD50's of 41 and 75 ng/mg of caterpillar, respectively. Interestingly, Z-stilbene was toxic at 300 ng/mg of caterpillar, but no toxicity was observed with DIDS or E-stilbene. The significant shift in potency between stilbene isomers indicates structure-activity relationships between stilbene chemistry and the binding site in FAW may exist. The data presented in this study defines the potency of select chloride channel modulators to FAW neural activity and survivorship to establish a platform for development of novel chemical agents to control FAW populations. Although stilbenes may hold promise for insecticide development, the low toxicity of the scaffolds tested in this study dampen enthusiasm for their development into FAW specific insecticides.


Assuntos
Inseticidas , Estilbenos , Animais , Resistência a Inseticidas , Inseticidas/toxicidade , Spodoptera , Estilbenos/toxicidade , Zea mays
11.
Pestic Biochem Physiol ; 179: 104967, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34802517

RESUMO

Meteorus pulchricornis (Wesmael) (Hymenoptera: Braconidae) is a predominant endoparasitoid of lepidopteran pests in mulberry fields. Extensive application of insecticides puts natural enemies under threat. UDP-glycosyltransferases (UGTs), as important detoxification enzymes, potentially contribute to the detoxification of pesticides in insects. To investigate the roles of UGTs in the process of tolerance towards commonly used insecticides in M. pulchricornis, ten UGT genes were identified from the transcriptome database of M. pulchricornis. Seven UGT genes contained full-length ORFs and shared 47.12-78.28% identity with other homologous hymenopteran insects. qRT-PCR validation revealed that UGT genes can be induced by treatment of sublethal doses of phoxim, cypermethrin and chlorfenapyr, respectively, and these upregulations were depending on the time post insecticide treatments. To further explore the functions of UGT genes, three MpulUGT genes were singly knocked down, which resulted in the decline of UGT expression and significantly increased mortality of parasitoids under sublethal doses of insecticides exposure. This study revealed that UGTs in M. pulchricornis contributed to the tolerance towards insecticides and provided basic insight into the insecticide detoxification mechanism in parasitoid wasps.


Assuntos
Inseticidas , Vespas , Animais , Glicosiltransferases/genética , Inseticidas/toxicidade , Difosfato de Uridina , Vespas/genética
12.
Pestic Biochem Physiol ; 179: 104973, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34802523

RESUMO

The fall armyworm (FAW) Spodoptera frugiperda (Lepidoptera: Noctuidae) is a severe agricultural pest, which has invaded into China in 2019 and caused heavy damage to maize. The γ-aminobutyric acid receptor (GABAR)-targeted insecticides including broflanilide, fluralaner and fipronil exhibit high toxicity towards lepidopteran pests. However, whether they could be used for control of FAW and their possible mode of action in FAW remain unclear. In this study, broflanilide, fluralaner and fipronil exhibited high oral toxicity in FAW larvae with median lethal dose (LD50) values of 0.677, 0.711, and 23.577 mg kg-1 (active ingredient/ artificial food), respectively. In the electrophysiological assay, fluralaner and fipronil could strongly inhibit GABA-induced currents of homomeric FAW resistance to dieldrin 1 (RDL1) receptor with median inhibitory concentration (IC50) values of 5.018 nM (95% confidence interval (CI) 2.864-8.789) and 8.595 nM (95% CI 5.105-14.47), respectively, whereas broflanilide could not. In addition, the cytochrome P450 (P450), glutathione-S-transferase (GST) and carboxylesterase (CarE) activities were positively response to broflanilide, P450 and GST to fluralaner, and GST and CarE to fipronil, respectively, compared with those of control. In conclusion, we firstly reported a notable insecticidal activity of three representative GABAR-targeted insecticides to FAW in vivo, and in vitro using electrophysiological assay. The GST is the primary detoxification enzyme for three tested insecticides. Our results would guide the rotational use of GABAR-targeted insecticides in field.


Assuntos
Inseticidas , Animais , Inseticidas/toxicidade , Larva , Receptores de GABA , Spodoptera , Zea mays
13.
Pestic Biochem Physiol ; 179: 104975, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34802525

RESUMO

Pesticides are one of the main causes of colony losses globally, posing a huge threat to the beekeeping industry. The fungicide carbendazim is commonly used on many crops worldwide, but the effects of fungicides on honey bees have received less attention than those of insecticides. Previous studies have shown that sublethal doses of carbendazim hinder growth and development and may destabilize and impede the development of honey bee colonies. The metabolome closely reflects brain activity at the functional level, allowing the effects of compounds such as fungicides to be investigated. Here, we established a model of carbendazim-treated honey bees, Apis mellifera, and used metabolomic approaches to better understand the effect of carbendazim on bee metabolic profiles. The results showed that 112 metabolites were significantly affected in carbendazim-treated bees compared to the control. Metabolites associated with energy and amino acid metabolism showed high abundance and were enriched for a wide range of pathways. In addition, the down-regulation of Aflatoxin B1exo-8,9-epoxide-GSH and glycerol diphosphate showed that carbenazim may affect the detoxification and immune system of honey bees. These results provide new insights into the interaction between fungicides and honey bees.


Assuntos
Inseticidas , Espectrometria de Massas em Tandem , Animais , Abelhas , Benzimidazóis , Carbamatos/toxicidade , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Inseticidas/toxicidade
14.
Pestic Biochem Physiol ; 179: 104977, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34802527

RESUMO

Chlorpyrifos (0,0-diethyl 0-(3,5,6-trichloro-2-pyridinyl)-phosphorothioate; (CPF)) is a widely used lipophilic organophosphorus insecticide that primarily manifests into central and peripheral nervous system toxicity. However, it is poorly investigated as a developmental neurotoxicant and thus remains less explored for pharmacological interventions as well. Berberine (BBR) is a benzylisoquinoline alkaloid, primarily found in the plants of Berberidaceae family, and is used for the synthesis of several bioactive derivatives. The goal of this study was to evaluate the CPF-induced neuronal damage through lactational route and analyze the neuroprotective efficacy of berberine (BBR), a potent antioxidant compound in the F1 generation. The environmentally relevant dose of CPF (3 mg/kg b.wt.) was administered via gavage to pregnant dams from postnatal day 1 to day 20 (PND 1-20). BBR (10 mg/kg b.wt.) was administered concurrently with CPF for the same duration as a co-treatment. Levels of reactive oxygen species, lipid peroxidation, membrane bound ATPases (Na+K+ATPase, Ca2+ATPase, and Mg2+ATPase), DNA damage, histomorphological alterations, cellular apoptosis were increased, and activities of glutathione reductase, endogenous antioxidant enzymes (SOD, CAT, GST, and GR) were decreased in cerebellum and cerebrum regions of CPF exposed pups. CPF triggered neuronal apoptosis by upregulating Bax and caspase-3 and downregulating Bcl-2. Co-treatment of BBR significantly attenuated these effects of CPF signifying oxidative stress mediated chlorpyrifos induced neuronal apoptosis. Berberine treatment ameliorated the CPF-induced downregulation of Bcl-2, Bax translocation, and up-regulation of caspase-3 in F1 pups. Therefore, BBR owing to its multiple pharmacological properties can be further explored for its therapeutic potential as an alternative neuroprotective agent against lactational exposure of chlorpyrifos-induced developmental neurotoxicity.


Assuntos
Berberina , Clorpirifos , Inseticidas , Animais , Berberina/toxicidade , Clorpirifos/toxicidade , Inseticidas/toxicidade , Compostos Organofosforados , Estresse Oxidativo , Ratos , Ratos Wistar
15.
Pestic Biochem Physiol ; 179: 104941, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34802531

RESUMO

Tribolium castaneum Herbst (Coleoptera: Tenebrionidae) is an insect popularly known as the red flour beetle, it is widely distributed worldwide and can cause serious damage to stored grains. Chemical control is the most used method for managing this pest, however, some substances are toxic to mammals and the environment. Therefore, the development of new effective and safe insecticides is necessary. Essential oils (EOs) can be considered as a potential alternative in the development of pesticides due to their physicochemical properties and varied effects against insects. In the current study, was determined the fumigant toxicity and biochemical effects of selected essential oils against T. castaneum. The 23 selected EOs were characterized by GC-MS and their fumigant lethal concentrations were determined. An exploratory Cluster analysis was performed to find a relationship between fumigant toxicity and chemical composition. Finally, the inhibition of the catalytic activity of acetylcholinesterase (AChE), glutathione S-transferase (GST) and catalase (CAT) was evaluated using protein homogenates obtained from T. castaneum. The results indicated that EOs with the highest fumigant potential were those with greater diversity in their composition, while the least active EOs presented mainly monoterpenes. The most active EOs were those obtained from Foeniculum vulgare and Zanthoxylum monophyllum with LC50 values of 16.23 and 18.54 µL/L air respectively. Regarding the inhibition of the enzymatic activity of the 23 EOs evaluated at 500 µL/L, only two caused an inhibition greater that 50% on AChE, which corresponded to EOs from Piper nigrum and Rosmarinus officinalis. Likewise, EOs from C. sinensis, Piper aduncum and Zanthoxylum monophyllum were the only ones able to inhibiting GST activity by more than 50%. Respecting CAT inhibition, 7 EOs caused and inhibition greater than 50%, highlighting those from Lavandula angustifolia, C. sempervirens and Eucalyptus sp. These results show that the EOs evaluated in this study seems to be a promising bio-controller of T. castaneum since have high fumigant toxicity and exert different mechanisms of action.


Assuntos
Besouros , Inseticidas , Óleos Voláteis , Tribolium , Acetilcolinesterase , Animais , Inseticidas/toxicidade , Óleos Voláteis/toxicidade
16.
Environ Pollut ; 291: 118221, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34740294

RESUMO

Sulfur, an essential macronutrient, plays important roles in plant development and stress mitigation. Sulfur deficiency, a common problem in agricultural soils, may disturb plant stress resistance and xenobiotic detoxification. In the present study, the function and mechanism of limited sulfur nutrition on the residues and phtotoxicity of imidacloprid were investigated in lettuce plants. Sulfur deficiency significantly increased imidacloprid accumulation in lettuce tissues, exacerbated imidacloprid biological toxicity by enhancing the accumulation of toxic metabolites, like imidacloprid-olefin. Simultaneously, imidacloprid-induced detoxification enzymes including cytochromes P450, glutathione S-transferases (GSTs) and glycosyltransferases were inhibited under limited sulfur supply. On the other hand, sulfur deficiency further enhanced the generation of reactive oxygen species and exacerbated lipid peroxidation in lettuce tissues. Sulfur deficiency mainly reduced the abundance of thiol groups, which are essential redox modulators as well as xenobiotic conjugators, and significantly inhibited GSTs expression. These results clearly suggested that sulfur deficiency inhibited the synthesis of sulfur-containing compounds, leading to increased accumulation of pesticide residues and toxic metabolites as well as reduced detoxification capacity, consequently leading to oxidative damage to plants. Therefore, moderate sulfur supply in regions where neonicotinoid insecticides are intensively and indiscriminately used may be an efficient strategy to reduce pesticide residues and the potential risk to ecosystem.


Assuntos
Inseticidas , Plântula , Ecossistema , Inseticidas/toxicidade , Alface , Neonicotinoides/toxicidade , Nitrocompostos/toxicidade , Compostos de Sulfidrila , Enxofre
17.
Ecotoxicol Environ Saf ; 226: 112840, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34619473

RESUMO

Within the framework of biocontrol development, several natural lipopeptides produced by Bacillus subtilis show well-documented anti-microbial properties, especially in orchards. However, the number of studies on their putative insecticidal effects remain low despite the growing interest to develop new strategies of orchards pests' control. The rosy apple aphid Dysaphis plantaginea is the major aphid pest causing great leaf damage to apple trees. In this study, we submitted young adult aphids to topical application of three different families of lipopeptides, Plipastatin (Fengycin), Mycosubtilin (Iturin), and Surfactin, either separately or as a ternary mixture. Their aphicidal effects were investigated at 1, 2.5 and 5 g/L, both at 1 h and 24 h after exposure, and their effects on aphid behavior were studied at the 2.5 g/L concentration at 24 h after exposure. When delivered alone, lipopeptides displayed contrasted effects varying from no aphicidal activity for Mycosubtilin to a mortality induced even at low concentrations by Surfactin. Surprisingly, locomotor activity of the surviving aphids was only affected by the two least lethal treatments, Mycosubtilin and the ternary mix. Their feeding behavior was only impacted by Surfactin, the most lethal treatment, that unexpectedly increased phloem sap ingestion. The results are discussed in the context of lipopeptides applicability for integrated pest management.


Assuntos
Afídeos , Bacillus , Inseticidas , Animais , Bacillus subtilis , Inseticidas/toxicidade , Lipopeptídeos/farmacologia
18.
Ecotoxicol Environ Saf ; 226: 112790, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34653840

RESUMO

The organophosphorus (OP) and carbamate (CB) insecticides are responsible for inhibition of the Acetylcholinesterase (AChE) enzyme. The AChE activity, therefore, has been demonstrated to be a potent biomarker for these insecticides in terrestrial and aquatic environments. The objective of this study was to investigate the response of AChE in the brain of four-week old fingerlings of silver perch, Bidyanus bidyanus exposed to OP and CB insecticides. The fish fingeling were exposed to three OPs and one CB insecticide as individual and their binary mixtures for 48 h. The OP insecticides with oxon (PO) as well as thion (PS) group gets oxidized to oxon analogs in biological systems. The 50% AChE inhibition (48 h EC50) in fingerling exposed to chlorpyrifos (CPF) and triazophos (TRZ) was evident at 2.3 and 6.7 µg/L, respectively. The toxicological interaction of three OPs and one CB insecticide was evaluated using the toxic unit method. A strong synergism was observed for binary combination of CPF with profenofos (PRF), and CPF with TAZ. In contrast, the mixture of TAZ with PRF and carbofuran (CBF) with CPF and PRF showed antagonistic behavior. Although OP and CB insecticides can break down rapidly in the environment, this study suggests that non-target aquatic biota may be exposed to mixtures of ChE-inhibiting insecticides for a period of several months, in agricultural regions where insecticides are applied for extended periods of the year. And at environmentally relevant concentrations such mixtures may lead to deleterious effects in non-target organisms.


Assuntos
Clorpirifos , Inseticidas , Percas , Acetilcolinesterase , Animais , Clorpirifos/toxicidade , Inibidores da Colinesterase/toxicidade , Inseticidas/toxicidade
19.
Artigo em Inglês | MEDLINE | ID: mdl-34639837

RESUMO

Currently, medical and stored grain pests are major concerns of public health and economies worldwide. The synthetic pesticides cause several side effects to human and non-target organisms. Copper nanoparticles (CuNPs) were synthesized from an aqueous extract of Metarhizium robertsii and screened for insecticidal activity against Anopheles stephensi, Aedes aegypti, Culex quinquefasciatus, Tenebrio molitor and other non-target organisms such as Artemia salina, Artemia nauplii, Eudrilus eugeniae and Eudrilus andrei. The synthesized copper nano-particles were characterized using, UV-vis spectrophotometer, Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Energy Dispersive X-Ray analysis (EDaX), High Resolution Scanning Electron Microscope (HR-SEM) and Atomic Force Microscope (AFM) analysis. Insects were exposed to 25 µg/mL concentration produced significant mortality against larvae of A. stephensi, A. aegypti, C. quinquefasciatus and T. molitor. The lower toxicity was observed on non-target organisms. Results showed that, M. robertsii mediated synthesized CuNPs is highly toxic to targeted pests while they had lower toxicity were observed on non-target organisms.


Assuntos
Aedes , Culex , Inseticidas , Nanopartículas Metálicas , Praguicidas , Animais , Cobre/toxicidade , Humanos , Inseticidas/toxicidade , Larva , Nanopartículas Metálicas/toxicidade , Metarhizium , Extratos Vegetais , Folhas de Planta , Prata
20.
Artigo em Inglês | MEDLINE | ID: mdl-34682593

RESUMO

Exposure to insecticides may result in various health problems. This study investigated the association between haematological parameters and exposure to a mixture of organophosphate (OP) and neonicotinoid (NEO) insecticides among male farmworkers in Fang district, Chiang Mai province, northern Thailand. Concentrations of urinary dialkylphosphates, non-specific metabolites of OPs, and NEOs and their metabolites and haematological parameters were measured in 143 male farmworkers. The Bayesian kernel machine regression model was employed to evaluate the associations. Exposure to a mixture of insecticides was significantly associated with the mean corpuscular haemoglobin concentration (MCHC) when the concentrations of all the compounds and their metabolites were at the 60th percentile or higher compared with the 50th percentile. Furthermore, exposure to clothianidin (CLO) showed a decreasing association with MCHC when all the other insecticides were at their mean concentrations. CLO was the most likely compound to reduce MCHC, and this was confirmed by sensitivity analysis. These findings suggest that exposure to NEO insecticides, especially CLO, affects the haematological status relating to haemoglobin parameters.


Assuntos
Inseticidas , Teorema de Bayes , Fazendeiros , Humanos , Inseticidas/toxicidade , Masculino , Neonicotinoides/toxicidade , Organofosfatos , Tailândia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA