RESUMO
The co-occurrence of pesticides in aquatic ecosystems highlights the need for studies investigating their potential toxicity as mixtures to the aquatic biota. Well-designed studies are essential to assess the presence and toxicity of relevant pesticide mixtures, particularly those such as the chloroacetamide herbicide metolachlor (MET), the triazole fungicide epoxiconazole (EP) and the diamide anthranilic insecticide chlorantraniliprole (CAP), which have not been previously tested, and whose co-occurrence is possible in waters close to cultivated areas. A solid phase extraction ultra-performance liquid chromatography-tandem quadrupole mass spectrometry method was developed to quantify equivalent toxicity concentrations for CAP, EP, and MET in artificial freshwater during acute toxicity tests. Compounds were separated within 1.30 min, showing linearity over the calibration ranges of 2-150 µgL-1 for CAP and 50-3000 µgL-1 for EP and MET. Detection and quantification limits were (µgL-1): 0.001 and 0.0037 MET; 0.000038 and 0.00013 EP; and 0.002 and 0.007 CAP, respectively. Precision and accuracy met intra-assay validation requirements. Recoveries were tested at low and high concentration levels and were between 77% and 120%. Additionally, matrix effect showed different behavior among compounds. In an acute toxicity test proposed, MET and EP remained stable (24 h), while CAP decayed 27% ± 4% in the same period. The method proved effective despite different concentrations in toxicity testing design.
Assuntos
Acetamidas , Compostos de Epóxi , Espectrometria de Massas em Tandem , Triazóis , Poluentes Químicos da Água , ortoaminobenzoatos , Poluentes Químicos da Água/toxicidade , Poluentes Químicos da Água/análise , Triazóis/toxicidade , Triazóis/análise , Acetamidas/toxicidade , Acetamidas/análise , Cromatografia Líquida de Alta Pressão , ortoaminobenzoatos/toxicidade , ortoaminobenzoatos/análise , Compostos de Epóxi/toxicidade , Compostos de Epóxi/análise , Animais , Inseticidas/toxicidade , Inseticidas/análise , Fungicidas Industriais/toxicidade , Fungicidas Industriais/análise , Herbicidas/toxicidade , Herbicidas/análiseRESUMO
Caterpillars of the genus Spodoptera are the main pests in soybean and cotton crops and Spodoptera cosmioides causes more severe losses than other caterpillars in these agricultural crops. However, there are few recommended insecticides for controlling this pest. Lambda-cyhalothrin is a pyrethroid used to control a wide spectrum of arthropods including lepidopterans. Therefore, the objective of this study was to evaluate the potential of lambda-cyhalothrin for the control of S. cosmioides. Specifically, toxicity and histopathological changes in the midgut were evaluated. The effectiveness of the insecticide was determined by estimating the different lethal concentrations (LCs) ââin the laboratory upon S. cosmioides. Lambda-cyhalothrin was found toxic to S. cosmioides (LC50 = 23.03 mg L-1 and LC90 = 174.8 mg L-1), with the survival reduced from 83.33% in the control to 37.89%, 16.66%, 0%, and 0% after 72 h of exposure to the LC25, LC50, LC75, and LC90 of lambda-cyhalothrin, respectively. Histopathological studies revealed that lambda-cyhalothrin caused damage to midgut cells, including epithelial disorganization, increased cytoplasmic vacuolization, brush border degeneration, nuclear chromatin condensation, and cell fragmentation, indicating cell death by apoptosis. It was concluded that lambda-cyhalothrin, a neurotoxic insecticide, caused damage to the midgut of S. cosmioides, compromising its physiology and indicating that it has potential to be used to control this pest.
Assuntos
Inseticidas , Nitrilas , Piretrinas , Spodoptera , Animais , Nitrilas/toxicidade , Piretrinas/toxicidade , Inseticidas/toxicidade , Spodoptera/efeitos dos fármacos , Trato Gastrointestinal/efeitos dos fármacos , Larva/efeitos dos fármacosRESUMO
Bees are essential pollinators that contribute to maintaining biodiversity and increasing agricultural production. However, by foraging on agricultural crops, bees may become contaminated with compounds used for pest control. In this study, we exposed bee (Apis mellifera L.) colonies to the insecticide imidacloprid (IMD) under field conditions to assess the occurrence of oxidative stress in larvae and pupae and investigate morphological changes in the fat body and midgut of larvae and midgut of adult bees. The apiary area was divided into three groups: control, commercial formulation containing IMD (Evidence® 700WG) (IMDCF), and IMD active ingredient (Sigma-Aldrich) (IMDAI). Treatment groups were fed syrup containing 1 µg L-1 IMD, whereas the control group was fed syrup only. Compared with the control, larvae exposed to IMDCF or IMDAI for 42 days exhibited morphological changes in the external body, midgut, and fat body. The midgut of adult bees contaminated with IMDCF showed only structural remnants of the peritrophic membrane and absence of regenerative cell nests. Oxidative stress analyses revealed that IMDCF-exposed larvae had higher nitrite and carbonylated protein contents and lower catalase and superoxide dismutase activity than control individuals. In pupae, IMDAI decreased catalase activity while increasing superoxide dismutase activity. These findings indicate that IMD has the potential to significantly impact the development of bees and their colonies by disrupting vital organs responsible for normal physiological functioning and overall activities of individuals. Oxidative stress, which was detected at different stages of bee development, may induce lipid, protein, and DNA oxidation, leading to cell death.
Assuntos
Inseticidas , Larva , Neonicotinoides , Nitrocompostos , Estresse Oxidativo , Pupa , Animais , Abelhas/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Neonicotinoides/toxicidade , Nitrocompostos/toxicidade , Pupa/efeitos dos fármacos , Larva/efeitos dos fármacos , Inseticidas/toxicidadeRESUMO
This study aimed to determine the chemical composition of ginger Zingiber officinale Roscoe (Zingiberaceae) and soursop Annona muricata Linn (Annonaceae) oils, formulate stable emulsions of these oils separately, as well as neem oil Azadirachta indica A. Juss (Meliaceae), and evaluate the insecticidal activity of these emulsions against Duponchelia fovealis Zeller, 1847 (Lepidoptera: Crambidae). Each stable emulsion contained an oil phase containing ginger, soursop, or neem oil, a fruit polyalcohol-based emulsifier, ethanol, or water. The insecticidal effect of the different oils and formulated emulsions was tested on the first- and second-instar caterpillars of D. fovealis. The majority of the compounds of the ginger essential oil were α-zingiberene (29%), geranial (14.9%), and α-farnesene (12.9%), and soursop oil had a higher percentage of oleic acid (43.73%), linoleic acid (29.51%), and palmitic acid (20.50%). The CL50 values of the soursop, neem, and ginger oils were 0.474, 0.473, and 0.602% for first-instar caterpillars and 2.25, 1.02, and 0.624% for second-instar caterpillars of D. fovealis. The formulated emulsions of ginger, soursop, and neem oils remained stable and exhibited toxicity in the first and second instars of D. fovealis development.
Assuntos
Lepidópteros , Óleos de Plantas , Animais , Lepidópteros/efeitos dos fármacos , Inseticidas/toxicidade , Annona/química , Zingiber officinale , Larva/efeitos dos fármacos , Mariposas/efeitos dos fármacosRESUMO
Chlorpyrifos is one of the most widely used insecticides globally, yet its toxicity for tropical aquatic ecosystems in Latin America has not been thoroughly evaluated. In this study, we conducted a 70-day mesocosm experiment to assess the effects of chlorpyrifos on zooplankton and macroinvertebrate communities representative of the Ecuadorian Amazon. Mesocosms were exposed to a single application of chlorpyrifos at four nominal concentrations (0.01, 0.1, 1, and 10 µg/L). Results showed rapid chlorpyrifos dissipation, with a half-life of 1.2 days. For some Rotifera species, including Polyarthra luminosa and Anuraeopsis sp., a consistent No Observed Effect Concentration (NOEC) of 0.01 µg/L was identified. Cyclopoida (e.g., Macrocyclops sp.) also displayed treatment-related declines, with a NOEC of 0.1 µg/L. Among macroinvertebrates, the most sensitive taxon was the Ephemeropteran Caenis sp. (NOEC: 0.1 µg/L), while other insect taxa (Odonata, Diptera) also showed significant treatment-related declines. Based on the response of some Rotifera species and the zooplankton community, we determined a mesocosm NOEC of 0.01 µg/L. The response of Rotifera taxa was explained by indirect effects resulting from a decline in copepod populations within the experimental systems, which led to an increase in Cladocera (e.g., Moina sp.), effective grazers on small rotifers. Our findings suggest a mesocosm NOEC slightly lower than those reported in other tropical and temperate studies (0.1 µg/L), potentially due to differences in species composition and interactions. Finally, our study highlights that measured chlorpyrifos concentrations in Latin American surface waters exceed levels at which both direct and indirect effects have been observed. Additional monitoring and regulatory measures are needed to control chlorpyrifos use and environmental release in tropical regions with intensive agriculture and high rainfall.
Assuntos
Clorpirifos , Inseticidas , Invertebrados , Poluentes Químicos da Água , Animais , Clorpirifos/toxicidade , Inseticidas/toxicidade , Poluentes Químicos da Água/toxicidade , Invertebrados/efeitos dos fármacos , Zooplâncton/efeitos dos fármacos , Água Doce , Monitoramento Ambiental , EquadorRESUMO
The use of pesticides in integrated rice-fish farming could have an impact on fish health. The present study aimed to evaluate, for the first time, the biological effects of the insecticide bifenthrin on fish (Piaractus mesopotamicus and Hoplosternum littorale) using a caging experiment. Fish were divided into two sites: control (C) and bifenthrin exposure (BF). Two cages (n = 8 fish/cage) per species were placed separately at each site. The BF application (Seizer ®) was carried out with a coastal sprayer according to the BF recommended dose for rice cultivation (0.1 L/ha). After 72 h, fish were collected, and gills, liver, brain, and muscle were dissected for the analysis of biomarkers of accumulation, oxidative stress, and neurotoxicity. In P. mesopotamicus, the main changes were observed in the muscle, where BF accumulated and induced neurotoxicity (inhibition of cholinesterase activity) and oxidative stress (activation of antioxidant enzymes, decreased glutathione levels, increased lipid peroxidation). The gills and liver also showed changes in some markers of the antioxidant system. In H. littorale, BF exposure induced changes in oxidative stress biomarkers in liver (activation of antioxidant enzymes and lipid peroxidation) and gill tissues (alteration in antioxidant markers). These results show that the use of bifenthrin in rice fields poses a risk to fish farming under current pesticide management practices. Furthermore, its use could affect other species in these agroecosystems, highlighting the need for further studies to assess the ecological and productive consequences in a context of increasing pyrethroid use worldwide.
Assuntos
Biomarcadores , Inseticidas , Oryza , Piretrinas , Poluentes Químicos da Água , Piretrinas/toxicidade , Animais , Inseticidas/toxicidade , Poluentes Químicos da Água/toxicidade , Biomarcadores/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismoRESUMO
Pesticides are diluted in products called solvents for spraying fields and for cell viability studies. This study aimed to determine whether pesticide solvents can alter the toxicity of endosulfan and Vero cell viability. Thus, the cytotoxicity of some diluents commonly used in pesticide solutions was evaluated by the neutral red incorporation technique and cell growth. Vero cells were exposed to endosulfan dissolved in sunflower (Helianthus annus, Linnaeus) oil, corn (Zea mays, Linnaeus) oil, dimethylsulfoxide (DMSO), and Tween 80, at a concentration of 1 µg L-1 for a period of 96 h. The results showed that both DMSO and Tween 80 induced a significant increase in cytotoxicity compared to sunflower oil and corn oil. Moreover, Tween 80 had a significant cytotoxic effect (P < 0.05) when compared to DMSO. The solvent can alter the toxicity of endosulfan, decreasing Vero cell viability, as was the case with DMSO and Tween 80.
Assuntos
Sobrevivência Celular , Endossulfano , Solventes , Células Vero , Animais , Chlorocebus aethiops , Solventes/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Endossulfano/toxicidade , Praguicidas/toxicidade , Dimetil Sulfóxido/toxicidade , Polissorbatos/toxicidade , Inseticidas/toxicidadeRESUMO
Chlorpyrifos (CPF) has been used worldwide, but its possible negative effects on macrophytes have been scarcely studied. The main goal of the present work was to assess the potential phytotoxic effects of CPF on different stages (seed and seedling) of the wetland macrophyte Bidens laevis. During the germination of seeds, stimulation of radicle growth at low concentrations of CPF (10 µg/L) and inhibition of its elongation at 80 µg/L CPF were observed. In seedlings, concentrations ≤ 160 µg/L CPF did not exhibit adverse effects on growth after 7 days of exposure, despite the decrease of photosynthetic pigments and carotenoids observed at 40 µg/L CPF compared to the control. Environmentally relevant concentrations of CPF altered neither oxidative stress biomarkers nor pigment contents in seedlings exposed for 48 h, suggesting CPF would be non-toxic to B. laevis in natural scenarios.
Assuntos
Bidens , Clorpirifos , Poluentes Químicos da Água , Áreas Alagadas , Clorpirifos/toxicidade , Poluentes Químicos da Água/toxicidade , Bidens/efeitos dos fármacos , Inseticidas/toxicidade , Germinação/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimentoRESUMO
Little information is available on the adverse effects of expired pesticides on the environment, so it is essential to characterize the risk of these chemicals to non-target organisms. Therefore, this work aims to estimate and compare the acute toxicity (LD50) of unexpired and expired formulations of malathion, chlorpyrifos, and lambda-cyhalothrin in rats and to determine their residues in the liver and kidneys of treated rats. This is the first study to investigate the toxic effects of expired pesticides on rats. The acute toxicity of expired lambda-cyhalothrin was higher than that of non-expired rats, while the opposite was observed in rats treated with malathion and chlorpyrifos. All formulations tested caused clinical signs of toxicity in the treated rats. The data showed that some expired formulations significantly affected body weight and estimated vital signs compared to non-expired pesticides. The data showed that the highest residues were found in the liver and kidneys of rats treated with both malathion formulations, followed by chlorpyrifos; however, the lowest residues were found in rats treated with lambda-cyhalothrin, which can be referred to as LD50 values of the insecticides tested. The residues detected after the 10th dose gradually decreased at the end of the recovery period, and their losses ranged from 80.0 to 95.4% in the liver and from 92.3 to 99.99% (undetectable). The results show that the toxic effects of expired and non-expired formulations are different. This underlines the need to dispose of expired compounds carefully to prevent their discharge into the ecosystem.
Assuntos
Clorpirifos , Inseticidas , Rim , Fígado , Malation , Nitrilas , Piretrinas , Animais , Rim/efeitos dos fármacos , Rim/química , Inseticidas/toxicidade , Fígado/efeitos dos fármacos , Clorpirifos/toxicidade , Piretrinas/toxicidade , Malation/toxicidade , Dose Letal Mediana , Nitrilas/toxicidade , Masculino , Ratos Wistar , Testes de Toxicidade Aguda , Resíduos de Praguicidas/toxicidade , RatosRESUMO
Anthranilic diamides (AD) are a modern class of insecticides used as alternatives to pyrethroids and neonicotinoids, particularly against lepidopteran pests. Despite their widespread use and presence in surface waters, little is known regarding their effects on amphibians. The aim of this study was to examine the effects of environmentally-relevant concentrations of AD insecticides chlorantraniliprole (CHLO) and cyantraniliprole (CYAN) on metamorphosis of the toad Rhinella arenarum. Tadpoles were exposed to CHLO or CYAN at concentrations ranging from 5 and 5000 µg/L from stage 27 until metamorphosis completion. Both insecticides produced a non-monotonic acceleration of the time required for individuals to progress through development and a decrease in the proportion of individuals completing metamorphosis, although a delay in metamorphosis was also observed at 5 µg/L of CHLO. Snout-vent length and body weight of metamorphosed toads were not markedly affected by either insecticide. CHLO was more toxic than CYAN, with a lowest observed effect concentration (LOEC) for CHLO on time to metamorphosis defined as 5 µg/L compared to 5000 µg/L for CYAN. The LOEC for reduced metamorphic success defined as 50 µg/L for CHLO compared to 500 µg/L for CYAN. As most effects occurred after stage 39, when metamorphosis depends upon thyroid hormones, it is conceivable that that AD insecticides act as endocrine disruptors. These findings suggest that contamination of surface waters with CHLO and CYAN may disrupt amphibian development in the wild and warrant further research to investigate the possibility of endocrine-disruption by ADs.
Assuntos
Inseticidas , Larva , Metamorfose Biológica , Poluentes Químicos da Água , ortoaminobenzoatos , Animais , Metamorfose Biológica/efeitos dos fármacos , Inseticidas/toxicidade , Poluentes Químicos da Água/toxicidade , ortoaminobenzoatos/toxicidade , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Pirazóis/toxicidade , Bufonidae/crescimento & desenvolvimento , Relação Dose-Resposta a DrogaRESUMO
The insecticide pyriproxyfen (PPF), commonly used in drinking water, has already been described as a potential neurotoxic agent in non-target organisms, particularly during embryonic development. Consequently, exposure to PPF can lead to congenital anomalies in the central nervous system. Therefore, understanding the impact of this insecticide on developing neural cells is a relevant concern that requires attention. Thus, this study aimed to investigate the effects of PPF on the proliferation, differentiation, migration, and cell death of neural cells by comparing embryos that develop exencephaly with normal embryos, after exposure to this insecticide. Chicken embryos, used as a study model, were exposed to concentrations of 0.01 and 10 mg/L PPF on embryonic day E1 and analyzed on embryonic day E10. Exposed embryos received 50 µL of PPF diluted in vehicle solution, and control embryos received exclusively 50 µL of vehicle solution. After exposure, embryos were categorized into control embryos, embryos with exencephaly exposed to PPF, and embryos without exencephaly exposed to PPF. The results showed that although the impact was differentiated in the forebrain and midbrain, both brain vesicles were affected by PPF exposure, and this was observed in embryos with and without exencephaly. The most evident changes observed in embryos with exencephaly were DNA damage accompanied by alterations in cell proliferation, increased apoptosis, and reduced neural differentiation and migration. Embryos without exencephaly showed DNA damage and reduced cell proliferation and migration. These cellular events directly interfered with the density and thickness of neural cell layers. Together, these results suggest that PPF exposure causes cellular damage during neurogenesis, regardless of whether embryos display or do not display external normal morphology. This nuanced understanding provides important insights into the neurotoxicity of PPF and its potential effects on inherent events in neurogenesis.
Assuntos
Piridinas , Animais , Embrião de Galinha/efeitos dos fármacos , Piridinas/toxicidade , Proliferação de Células/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Inseticidas/toxicidade , Diferenciação Celular/efeitos dos fármacos , Defeitos do Tubo Neural/induzido quimicamente , Defeitos do Tubo Neural/patologia , Defeitos do Tubo Neural/embriologia , Neurônios/efeitos dos fármacos , Neurônios/patologia , Desenvolvimento Embrionário/efeitos dos fármacosRESUMO
This study aimed to evaluate the toxicity of Piper hispidinervum essential oil (PHEO) against 11 Brazilian populations of Sitophilus zeamais (Coleoptera: Curculionidae). The effects of sublethal doses of PHEO on the behavior (walking and flying), respiration, and population growth (ri) of the insect populations were investigated. PHEO toxicity was determined through concentration-mortality bioassays, with mortality curves established using increasing PHEO concentrations ranging from 140.00 to 1000.00 µL kg-1. Behavior was evaluated based on walking distance, walking time, walking speed, walking time proportion, flight height, and flight takeoff success. Respiration was measured via the respiratory rate, while population growth (ri) was assessed through the instantaneous growth rate. All 11 populations of S. zeamais were susceptible to PHEO, showing no signs of resistance. The populations exhibited varying behavioral and physiological responses to sublethal exposure to PHEO, indicating different mitigation strategies. The results confirm that PHEO possesses insecticidal potential for controlling S. zeamais populations. However, the observed behavioral and physiological responses should be considered when establishing control measures in pest management programs for stored products.
Assuntos
Inseticidas , Óleos Voláteis , Piper , Gorgulhos , Animais , Óleos Voláteis/farmacologia , Óleos Voláteis/química , Gorgulhos/efeitos dos fármacos , Gorgulhos/fisiologia , Piper/química , Inseticidas/farmacologia , Inseticidas/toxicidade , Comportamento Animal/efeitos dos fármacos , Óleos de Plantas/farmacologia , Óleos de Plantas/químicaRESUMO
The widely used insecticide chlorpyrifos (CP) is known to inhibit acetylcholinesterase (AChE) activity attributed to result in various neurological disorders and acetylcholine-dependent organ functions including heart, skeletal muscle, lung, gastrointestinal tract, and central nervous systems. Enzyme reactivators, such as oximes, are known to restore AChE activity and mitigate adverse effects. The identification of compounds that reactivate AChE constitute agents with important therapeutic beneficial effects in cases of pesticide poisoning. However, the screening of novel drugs using traditional models may raise ethical concerns. This study aimed to investigate the potential of Drosophila melanogaster as a model organism for screening AChE reactivators, with a focus on organophosphate poisoning. The efficacy of several oximes, including pralidoxime, trimedoxime, obidoxime, methoxime, HI-6, K027, and K048, against CP-induced AChE activity inhibition in D. melanogaster was determined in silico, in vitro, and in vivo experiments. Molecular docking studies indicated a strong interaction between studied oximes and the active-site gorge of AChE. Data showed that selected oximes (100 µM) are effective in the reactivation of AChE inhibited by CP (10 µM) in vitro. Finally, in vivo investigations demonstrated that selected oximes, pralidoxime and K048 (1.5 ppm), reversed the locomotor deficits, inhibition of AChE activity as well as lowered the mortality rates induced by CP (0.75 ppm). Our findings contribute to utilization of D. melanogaster as a robust model for determination of actions of identified new AChE inhibitory agents with more effective therapeutic properties that those currently in use in the clinical practice in treatment of AChE associated disorders.
Assuntos
Acetilcolinesterase , Clorpirifos , Reativadores da Colinesterase , Drosophila melanogaster , Simulação de Acoplamento Molecular , Oximas , Animais , Drosophila melanogaster/efeitos dos fármacos , Drosophila melanogaster/enzimologia , Reativadores da Colinesterase/farmacologia , Clorpirifos/toxicidade , Acetilcolinesterase/metabolismo , Oximas/farmacologia , Modelos Animais , Inseticidas/toxicidade , Inibidores da Colinesterase/toxicidadeRESUMO
We compared the effects of lambda-cyhalothrin as the pure active ingredient and as a formulated product (Zero®), on the larval stage of the autochthonous species Boana pulchella. We evaluated ecotoxicological endpoints, behavioral and developmental alterations, and the biochemical detoxifying, neurotoxic, and oxidative stress responses, covering a wide concentration range from environmental to high application levels. Both pyrethroid preparations displayed similar ecotoxicity (median lethal concentration of ~0.5 mg/L), with the lethal effect of Zero® being more pronounced than that of the active ingredient. Sublethal behavioral alterations in natatory activity were observed at 1000 times lower concentrations, indicating the ecological hazard of tadpole exposure to this pyrethroid at environmentally relevant concentrations. Biochemical endpoints in B. pulchella larvae showed significant responses to lambda-cyhalothrin in the ng/L range; these responses were different for the pure or the formulated product, and they were variable at higher concentrations. Principal components analysis confirmed the prevalence of biochemical responses as early endpoints at the lowest lambda-cyhalothrin concentrations; the Integrated Biomarker Response Index proportionally increased with pyrethroid concentration in a similar way for the pure and the formulated products. We conclude that lambda-cyhalothrin is of concern from an environmental perspective, with particular emphasis on autochthonous anuran development. The battery of biochemical biomarkers included in our study showed a consistent integrated biomarker response, indicating that this is a potent tool for monitoring impacts on amphibians. Environ Toxicol Chem 2024;43:2134-2144. © 2024 SETAC.
Assuntos
Biomarcadores , Inseticidas , Larva , Nitrilas , Piretrinas , Piretrinas/toxicidade , Animais , Nitrilas/toxicidade , Larva/efeitos dos fármacos , Inseticidas/toxicidade , Poluentes Químicos da Água/toxicidade , Anuros , Estresse Oxidativo/efeitos dos fármacosRESUMO
Neurodevelopmental disorders, such as autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD), are characterized by persistent changes in communication and social interaction, as well as restricted and stereotyped patterns of behavior. The complex etiology of these disorders possibly combines the effects of multiple genes and environmental factors. Hence, exposure to insecticides such as imidacloprid (IMI) has been used to replicate the changes observed in these disorders. Lutein is known for its anti-inflammatory and antioxidant properties and is associated with neuroprotective effects. Therefore, the aim of this study was to evaluate the protective effect of lutein-loaded nanoparticles, along with their mechanisms of action, on Drosophila melanogaster offspring exposed to IMI-induced damage. To simulate the neurodevelopmental disorder model, flies were exposed to a diet containing IMI for 7 days. Posteriorly, their offspring were exposed to a diet containing lutein-loaded nanoparticles for a period of 24 h, and male and female flies were subjected to behavioral and biochemical evaluations. Treatment with lutein-loaded nanoparticles reversed the parameters of hyperactivity, aggressiveness, social interaction, repetitive movements, and anxiety in the offspring of flies exposed to IMI. It also protected markers of oxidative stress and cell viability, in addition to preventing the reduction of Nrf2 and Shank3 immunoreactivity. These results demonstrate that the damage induced by exposure to IMI was restored through treatment with lutein-loaded nanoparticles, elucidating lutein's mechanisms of action as a therapeutic agent, which, after further studies, can become a co-adjuvant in the treatment of neurodevelopmental disorders, such as ASD and ADHD.
Assuntos
Comportamento Animal , Drosophila melanogaster , Luteína , Nanopartículas , Nitrocompostos , Animais , Drosophila melanogaster/efeitos dos fármacos , Luteína/farmacologia , Luteína/administração & dosagem , Comportamento Animal/efeitos dos fármacos , Masculino , Feminino , Nitrocompostos/toxicidade , Neonicotinoides/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Inseticidas/toxicidade , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/administração & dosagem , Transtornos do Neurodesenvolvimento/prevenção & controle , Transtornos do Neurodesenvolvimento/induzido quimicamente , Transtornos do Neurodesenvolvimento/metabolismo , Antioxidantes/farmacologia , Antioxidantes/metabolismoRESUMO
Insect growth regulators (IGRs) have been playing a major role in the effective management of a range of stored product insect pests including species that have developed resistance to major groups of insecticides, such as organophosphates (OPs) and synthetic pyrethroids (SPs). In the present study, we evaluated the efficacy of S-methoprene alone and in combination with piperonyl butoxide (PBO), an adjuvant component of insecticides for synergy, against two strains, Lab-S (susceptible) and Met-R (Methoprene resistant) of an economically important pest species, the lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae). Adults of both Lab-S and Met-R strains were exposed to wheat treated with multiple concentrations of S-methoprene ranging from 0.001 to 0.01 and 10 to 60 mg/kg, respectively, alone and in combination with PBO. A variety of concentrations, including 0.27, 0.53, 0.80, and 1.07 g/kg, were evaluated for PBO. Mortality of adults and percent reduction in progeny were assessed after 14 and 65 days of treatment, respectively. As anticipated, the adult mortality rates of both strains were not significantly affected by S-methoprene alone. However, the number of progeny produced confirmed that the Met-R strain exhibited a high level of resistance to S-methoprene alone, with over 50 F1 progeny adults surviving in wheat treated with the maximal rate, 10 mg/kg. In contrast, the toxicity of S-methoprene was increased against the same resistant strain (Met-R), by 0.80 or 1.07 g/kg of PBO in combination treatment, resulting in a significant reduction in progeny numbers (25 adults per container). Although the tested concentrations of S-methoprene and PBO were well above the currently registered rate globally, our results highlight the fact that PBO enhances the toxicity of S-methoprene to some extent, reaffirming that the mode of action of the latter involves the inhibition of mixed-function oxidases (MFOs) and highlights the need for further research into developing potential binary or triplet formulations containing these two active ingredients (AIs).
Assuntos
Besouros , Inseticidas , Metoprene , Butóxido de Piperonila , Animais , Inseticidas/toxicidade , Besouros/efeitos dos fármacos , Triticum , Sinergistas de PraguicidasRESUMO
Wetlands play a crucial role in providing valuable ecosystem services, including the removal of various pollutants. In agricultural basins, wetlands are exposed to agrochemical loads. This study aims to assess the attenuation effect of the ubiquitous macrophyte Azolla spp. on the toxicity of lambda-cyhalothrin to sensitive aquatic organisms. An indoor mesocosm experiment was conducted to compare the concentration of lambda-cyhalothrin at different time points after pesticide application in vegetated and unvegetated treatments, including a control without pesticide addition. Toxicity tests were performed throughout the experiment on three organisms: a fish (Cnesterodon decemmaculatus), a macroinvertebrate (Hyalella curvispina), and an amphibian (Boana pulchella). The results demonstrated that lambda-cyhalothrin concentration and toxicity in water were significantly lower in the Azolla spp. treatment. Furthermore, the half-life of lambda-cyhalothrin decreased from 1.2 days in the unvegetated treatment to 0.4 days in the vegetated treatment. The vegetated treatment also resulted in a significantly lower mortality rate for both H. curvispina and C. decemmaculatus. However, no mortality was observed in B. pulchella for any of the treatments. Sublethal effects were observed in this organism, such as lateral bending of the tail and impairment of the ability to swim, which were attenuated in the vegetated treatment. We conclude that Azolla spp. can effectively reduce the concentration and toxicity of lambda-cyhalothrin, suggesting its potential use in farm-scale best management practices to mitigate the effects of pesticide loads from adjacent crops.
Assuntos
Organismos Aquáticos , Nitrilas , Piretrinas , Poluentes Químicos da Água , Piretrinas/toxicidade , Nitrilas/toxicidade , Animais , Poluentes Químicos da Água/toxicidade , Organismos Aquáticos/efeitos dos fármacos , Áreas Alagadas , Inseticidas/toxicidade , Peixes/fisiologia , Anfípodes/efeitos dos fármacos , Anfípodes/fisiologiaRESUMO
Fipronil, a pesticide widely used to control agricultural and household insect pests, blocks insect GABAA and glutamate (GluCl) ionotropic receptors, resulting in uncontrolled hyperexcitation and paralysis that eventually leads to death. The use of fipronil is controversial because unintentional exposure to this compound may contribute to the ongoing global decline of insect pollinator populations. Although the sublethal effects of fipronil have been linked to aberrant behavior and impaired olfactory learning in insects, the precise mechanisms involved in these responses remain unclear. In this article, we highlight recent studies that have investigated the interaction among different pathways involved in the ability of fipronil to modulate insect behavior, with particular emphasis on the role of GABAergic neurotransmission in fine-tuning the integration of sensorial responses and insect behavior. Recent findings suggest that fipronil can also cause functional alterations that affect synaptic organization and the availability of metal ions in the brain.
Assuntos
Comportamento Animal , Insetos , Inseticidas , Pirazóis , Animais , Pirazóis/toxicidade , Insetos/efeitos dos fármacos , Insetos/fisiologia , Inseticidas/toxicidade , Comportamento Animal/efeitos dos fármacos , Transmissão Sináptica/efeitos dos fármacosRESUMO
Taking into consideration that bees can be contaminated by pesticides through the ingestion of contaminated floral resources, we can utilize genetic techniques to assess effects that are scarcely observed in behavioral studies. This study aimed to investigate the genetic effects of ingesting lethal and sublethal doses of the insecticide fipronil in foraging honey bees during two periods of acute exposure. Bees were exposed to fipronil through contaminated honey syrup at two dosages (LD50 = 0.19 µg/bee; LD50/100 = 0.0019 µg/bee) and for two durations (1 and 4 h). Following exposure, we measured syrup consumption per bee, analyzed the transcriptome of bee brain tissue, and identified differentially expressed genes (DEGs), categorizing them functionally based on gene ontology (GO). The results revealed a significant genetic response in honey bees after exposure to fipronil, regardless of the dosage used. Fipronil affected various metabolic, transport, and cellular regulation pathways, as well as detoxification processes and xenobiotic substance detection. Additionally, the downregulation of several DEGs belonging to the olfactory-binding protein (OBP) family was observed, suggesting potential physiological alterations in bees that may lead to disoriented behaviors and reduced foraging efficiency.
Assuntos
Expressão Gênica , Pirazóis , Animais , Abelhas/efeitos dos fármacos , Pirazóis/toxicidade , Expressão Gênica/efeitos dos fármacos , Contaminação de Alimentos , Inseticidas/toxicidadeRESUMO
The honey bee Apis mellifera plays a significant role as a pollinator of native and cultivated plants, by increasing the productivity of several cultures, preserving the flora, and producing forest seeds. However, bee populations are declining worldwide, including A. mellifera, due to Colony Collapse Disorder, mainly resulting from the constant use of pesticides in the crops. Teflubenzuron is a physiological insecticide that belongs to the benzoylurea group, which inhibits chitin synthesis, the main component of the insect integument classified as safe for non-target insects, including bees. However, its effect on non-target organs of insects remains unknown. The midgut is the main organ of the digestive tract, which works in digestion and absorption and may be exposed to pesticides that contaminate food resources. The present work aimed to verify if the insecticide teflubenzuron is toxic and has histopathological effects on the midgut of A. mellifera adult workers. Workers exposed orally and chronically to the field-realistic concentration of teflubenzuron present 81.54% mortality. The epithelium of the midgut of these bees presents high vacuolization, spherocrystals, cell fragments released to the organ lumen, apocrine secretion, nuclear pyknosis, loss of cell-cell contact, and damage to regenerative cell nests and to the peritrophic matrix. These results indicate that the chitin synthesis-inhibiting insecticide teflubenzuron is toxic to A. mellifera after chronic oral exposure, at realistic field concentration, although it is classified as non-toxic to adult and non-target insects.