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1.
Environ Pollut ; 292(Pt A): 118212, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34582921

RESUMEN

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.


Asunto(s)
Acaricidas , Insecticidas , Virus ARN , Varroidae , Acaricidas/toxicidad , Animales , Abejas , Insecticidas/toxicidad
2.
Environ Pollut ; 292(Pt A): 118317, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34634407

RESUMEN

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.


Asunto(s)
Insecticidas , Animales , Guanidinas/toxicidad , Insecticidas/toxicidad , Neonicotinoides/toxicidad , Tiazoles , Distribución Tisular , Pez Cebra
3.
Environ Pollut ; 292(Pt A): 118335, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34637835

RESUMEN

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.


Asunto(s)
Fungicidas Industriales , Galliformes , Insecticidas , Animales , Fungicidas Industriales/toxicidad , Insecticidas/análisis , Insecticidas/toxicidad , Semillas/química , España
4.
Sci Total Environ ; 804: 150254, 2022 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-34798758

RESUMEN

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.


Asunto(s)
Proteínas de Drosophila , Drosophilidae , Insecticidas , Plaguicidas , Animales , Proteína 7 Relacionada con la Autofagia , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Drosophilidae/metabolismo , Femenino , Insecticidas/toxicidad , Masculino , Neonicotinoides , Reproducción , Transcriptoma
5.
Chemosphere ; 286(Pt 1): 131642, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34351280

RESUMEN

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.


Asunto(s)
Insecticidas , Insulina , Adulto , Femenino , Glucosa , Homeostasis , Humanos , Insecticidas/toxicidad , Masculino , Neonicotinoides , Nitrocompuestos , Encuestas Nutricionales , Estudios Prospectivos
6.
Biol Trace Elem Res ; 200(1): 228-237, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33566284

RESUMEN

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.


Asunto(s)
Cloropirifos , Insecticidas , Selenio , Oligoelementos , Animales , Cloropirifos/toxicidad , Insecticidas/toxicidad , Masculino , Ratas , Ratas Sprague-Dawley , Selenio/farmacología
7.
Sci Total Environ ; 803: 150026, 2022 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-34500277

RESUMEN

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.


Asunto(s)
Heterópteros , Insecticidas , Animales , Humanos , Resistencia a los Insecticidas , Insecticidas/toxicidad , Pirazoles , Medición de Riesgo
8.
Environ Pollut ; 291: 118221, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34740294

RESUMEN

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.


Asunto(s)
Insecticidas , Plantones , Ecosistema , Insecticidas/toxicidad , Lechuga , Neonicotinoides/toxicidad , Nitrocompuestos/toxicidad , Compuestos de Sulfhidrilo , Azufre
9.
Pestic Biochem Physiol ; 179: 104965, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34802515

RESUMEN

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.


Asunto(s)
Insecticidas , Estilbenos , Animales , Resistencia a los Insecticidas , Insecticidas/toxicidad , Spodoptera , Estilbenos/toxicidad , Zea mays
10.
Pestic Biochem Physiol ; 179: 104967, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34802517

RESUMEN

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.


Asunto(s)
Insecticidas , Avispas , Animales , Glicosiltransferasas/genética , Insecticidas/toxicidad , Uridina Difosfato , Avispas/genética
11.
Pestic Biochem Physiol ; 179: 104973, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34802523

RESUMEN

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.


Asunto(s)
Insecticidas , Animales , Insecticidas/toxicidad , Larva , Receptores de GABA , Spodoptera , Zea mays
12.
Pestic Biochem Physiol ; 179: 104975, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34802525

RESUMEN

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.


Asunto(s)
Insecticidas , Espectrometría de Masas en Tándem , Animales , Abejas , Bencimidazoles , Carbamatos/toxicidad , Cromatografía Líquida de Alta Presión , Cromatografía Liquida , Insecticidas/toxicidad
13.
Pestic Biochem Physiol ; 179: 104977, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34802527

RESUMEN

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.


Asunto(s)
Berberina , Cloropirifos , Insecticidas , Animales , Berberina/toxicidad , Cloropirifos/toxicidad , Insecticidas/toxicidad , Compuestos Organofosforados , Estrés Oxidativo , Ratas , Ratas Wistar
14.
Pestic Biochem Physiol ; 179: 104941, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34802531

RESUMEN

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.


Asunto(s)
Escarabajos , Insecticidas , Aceites Volátiles , Tribolium , Acetilcolinesterasa , Animales , Insecticidas/toxicidad , Aceites Volátiles/toxicidad
15.
Toxicon ; 203: 22-29, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34600912

RESUMEN

Phenolics are the most abundant secondary metabolites of plants that are widely distributed in the plant kingdom. In the last few years, the development and identification of phenolic compounds from various plants have become a major area of the environment and health-related research. In the present study, different phenolic compounds were purified from the bark of the medicinally important plant Acacia nilotica which is rich in polyphenols and were evaluated for their insecticidal potential against a polyphagous pest, Spodoptera litura (Fab.). The compounds viz. Catechin, Chlorogenic acid, and Umbelliferone were purified from ethyl acetate-acetone (E-AE) fraction using Semi-preparative HPLC and were identified using melting point determination, Nuclear Magnetic Resonance (NMR), and Mass Spectroscopy (MS). These phenolic compounds recorded detrimental effects on the growth and development of second instar larvae (6 days old) of S. litura. The larval growth, survival, adult emergence, pupal weight, and different nutritional indices were adversely affected by the various concentrations of these purified compounds. The findings revealed the insecticidal potential of polyphenols obtained from the bark of A. nilotica, which can provide an alternative for resistance management, as these plant phytochemicals are highly effective against insecticide-resistant insect pests.


Asunto(s)
Acacia , Insecticidas , Animales , Insecticidas/toxicidad , Larva , Fenoles/toxicidad , Spodoptera
16.
Ecotoxicol Environ Saf ; 227: 112909, 2021 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-34673414

RESUMEN

Wilforine, a compound of sesquiterpene alkaloids isolated from Tripterygium wilfordii, exhibits excellent insecticidal activity against Mythimna separata. In order to clarify the action mechanism of wilforine, the plasma membrane calcium transporting ATPase (PMCA) and inositol 1,4,5-trisphosphate receptor (IP3R) from M. separata were studied. Results showed that the open reading frame of MsIP3R and MsPMCA were 8118 bp and 3438 bp in length, as well as encoded 2706 and 1146 amino acids, respectively. Multiple sequence alignment and phylogenetic analysis revealed that the MsIP3R and MsPMCA had high homology with the IP3R and PMCA of other insects, but had low similarity with those of mammals, which means the IP3R and PMCA have potential to be the novel targets of insecticides with high selectivity between mammals and insects. Both MsIP3R and MsPMCA genes existed throughout the life cycle of M. separata, and were all predominantly expressed in somatic muscle of fifth-instar larvae and the adults. The susceptibilities of PMCA-silenced M. separata to wilforine were significantly lower than that of the normal M. separata, which illustrates that PMCA could be one of the targets of wilforine. However, the susceptibilities of IP3R-silenced M. separata to wilforine did not change significantly compared with the susceptibilities of normal M. separata, which shows that wilforine may not interact with the IP3R protein. These findings provide clues for elucidating the insecticidal mechanism of wilforine.


Asunto(s)
Insecticidas , Mariposas Nocturnas , Animales , Silenciador del Gen , Inositol , Receptores de Inositol 1,4,5-Trifosfato/genética , Insecticidas/toxicidad , Lactonas , Larva/genética , Mariposas Nocturnas/genética , Filogenia , ATPasas Transportadoras de Calcio de la Membrana Plasmática , Piridinas , Interferencia de ARN
17.
Ecotoxicol Environ Saf ; 227: 112917, 2021 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-34678628

RESUMEN

Imidacloprid (IMI) and thiamethoxam (THM) are two commonly applied neonicotinoid insecticides. IMI and THM could cause negative impacts on non-target organisms like bees. However, the information about neurotoxicity of IMI and THM in fish is still scarce. Here we investigated the effects of IMI and THM on locomotor behavior, AChE activity, and transcription of genes related to synaptic transmission in zebrafish exposed to IMI and THM with concentrations of 50 ng L-1 to 50,000 ng L-1 at 14 day post fertilization (dpf), 21 dpf, 28 dpf and 35 dpf. Our results showed that IMI and THM significantly influenced the locomotor activity in larvae at 28 dpf and 35 dpf. THM elevated AChE activity at 28 dpf. The qPCR data revealed that IMI and THM affected the transcription of marker genes belonging to the synapse from 14 dpf to 35 dpf. Furthermore, IMI and THM mainly affected transcription of key genes in γ-aminobutyric acid, dopamine and serotonin pathways in larvae at 28 dpf and 35 dpf. These results demonstrated the neurotoxicity of IMI and THM in zebrafish. The findings from this study suggested that IMI and THM in the aquatic environment may pose potential risks to fish fitness and survival.


Asunto(s)
Insecticidas , Contaminantes Químicos del Agua , Animales , Abejas , Insecticidas/análisis , Insecticidas/toxicidad , Neonicotinoides/toxicidad , Nitrocompuestos/toxicidad , Transmisión Sináptica , Tiametoxam , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad , Pez Cebra/genética
18.
Ecotoxicol Environ Saf ; 226: 112840, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34619473

RESUMEN

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.


Asunto(s)
Áfidos , Bacillus , Insecticidas , Animales , Bacillus subtilis , Insecticidas/toxicidad , Lipopéptidos/farmacología
19.
Aquat Toxicol ; 240: 105992, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34656895

RESUMEN

Imidacloprid is one of the most used neonicotinoid insecticides all over the world and is considered as a contaminant of concern due to its high toxicity potential to aquatic organisms. However, the majority of the studies that have evaluated the effects of imidacloprid on aquatic organisms were conducted under temperate conditions. In the present study, a mesocosm experiment was conducted under sub-tropical conditions to assess the effects of imidacloprid on the structure (macroinvertebrates, zooplankton and phytoplankton) and functional endpoints of an aquatic ecosystem and to compare the results with similar temperate and (sub-)tropical mesocosm studies. Imidacloprid (0, 0.03, 0.3 and 3 µg/L) was applied to 13 mesocosms weekly over a period of 4 weeks, followed by a one month recovery period. At the community level a lowest NOECcommunity of 0.03 µg/L was calculated for the zooplankton, phytoplankton and macroinvertebrate communities. The highest sensitivity to imidacloprid (NOEC < 0.03 µg/L) were observed for Gerris sp., Diaptomus sp. and Brachionus quadridentatus. Imidacloprid induced population declines of the larger zooplankton species (Diaptomus sp. and Ostracoda) resulted in increased rotifer abundances and shifted the phytoplankton community to a graze resistant gelatinous cyanobacteria dominated ecosystem. These cyanobacteria blooms occurred at all different concentrations and could pose an important public health and environmental concern. Although there are some differences in species and community sensitivity between the present and the other (sub-)topical mesocosm studies, it can be observed that all show a similar general community response to imidacloprid. Under (sub-)tropical conditions, the toxic effects of imidacloprid occur at lower concentrations than found for temperate ecosystems.


Asunto(s)
Cianobacterias , Insecticidas , Contaminantes Químicos del Agua , Animales , Ecosistema , Agua Dulce , Insecticidas/toxicidad , Neonicotinoides/toxicidad , Nitrocompuestos , Clima Tropical , Contaminantes Químicos del Agua/toxicidad , Zooplancton
20.
Artículo en Inglés | MEDLINE | ID: mdl-34682593

RESUMEN

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.


Asunto(s)
Insecticidas , Teorema de Bayes , Agricultores , Humanos , Insecticidas/toxicidad , Masculino , Neonicotinoides/toxicidad , Organofosfatos , Tailandia
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