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1.
Pestic Biochem Physiol ; 187: 105190, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36127050

RESUMO

Avermectin is one of the most widely used pesticides, but its toxicity to non-target organisms, especially aquatic organisms, has been ignored. Therefore, an acute spleen injury model of avermectin in carp was established to assess the non-target toxicity of avermectin to carp. In this study, 3.005 µg/L and 12.02 µg/L were set as the low and high dose groups of avermectin, respectively, and a four days acute exposure experiment was conducted. Pathological structure observation showed that avermectin damaged spleen tissue structure and produced inflammatory cell infiltration. Biochemical analysis showed that avermectin significantly reduced the activities of antioxidant enzymes CAT, SOD, and GSH-px, but increased the content of MDA, a marker of oxidative damage. Avermectin exposure also significantly increased the transcription levels of inflammatory cytokines such as IL-1ß, IL-6, TNF-α, and INOS, and also significantly enhanced the activity of the inflammatory mediator iNOS, but suppressed the transcription levels of anti-inflammatory factors TGF-ß1 and IL-10. In addition, TUNEL detected that the apoptosis rate increased significantly with the increase of avermectin dosage, and the transcription levels of apoptosis-related genes BAX, P53, and Caspase 3/9 also increased in a dose-dependent manner. This study is preliminary evidence that avermectin induces spleen injury in carp through oxidative stress, inflammation, and apoptosis, which has important implications for subsequent studies on the effects of avermectin on non-target organisms.


Assuntos
Carpas , Praguicidas , Animais , Antioxidantes/metabolismo , Apoptose , Carpas/metabolismo , Caspase 3/metabolismo , Inflamação/induzido quimicamente , Mediadores da Inflamação/farmacologia , Interleucina-10/metabolismo , Interleucina-10/farmacologia , Interleucina-6/farmacologia , Ivermectina/análogos & derivados , Estresse Oxidativo , Praguicidas/farmacologia , Baço/metabolismo , Superóxido Dismutase/metabolismo , Fator de Crescimento Transformador beta1/farmacologia , Fator de Necrose Tumoral alfa , Proteína Supressora de Tumor p53 , Proteína X Associada a bcl-2
2.
Pestic Biochem Physiol ; 187: 105202, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36127053

RESUMO

Overproduction of free radicals and inflammation could lead to maneb (MB)- and paraquat (PQ)-induced toxicity in the polymorphonuclear leukocytes (PMNs). Cyclooxygenase-2 (COX-2), an inducible COX, is imperative in the pesticides-induced pathological alterations. However, its role in MB- and PQ-induced toxicity in the PMNs is not yet clearly deciphered. The current study explored the contribution of COX-2 in MB- and PQ-induced toxicity in the PMNs and the mechanism involved therein. Combined MB and PQ augmented the production of free radicals, lipid peroxides and activity of superoxide dismutase (SOD) in the rat PMNs. While combined MB and PQ elevated the expression of COX-2 protein, activation of nuclear factor-kappa B (NF-κB) and phosphorylation of c-Jun N-terminal kinase (JNK), release of mitochondrial cytochrome c and levels of procaspase-3/9 were attenuated in the PMNs. Celecoxib (CXB), a COX-2 inhibitor, ameliorated the combined MB and PQ-induced modulations in the PMNs. MB and PQ augmented the free radical generation, COX-2 protein expression, NF-κB activation and JNK phosphorylation and reduced the cell viability of cultured rat PMNs and human leukemic HL60. MB and PQ elevated mitochondrial cytochrome c release and poly (ADP-ribose) polymerase cleavage whilst procaspase-3/9 levels were attenuated in the cultured PMNs. MB and PQ also increased the levels of phosphorylated c-jun and caspase-3 activity in the HL60 cells. CXB; SP600125, a JNK-inhibitor and pyrrolidine dithiocarbamate (PDTC), a NF-κB inhibitor, rescued from MB and PQ-induced changes in the PMNs and HL60 cells. However, CXB offered the maximum protection among the three. The results show that COX-2 activates apoptosis in the PMNs following MB and PQ intoxication, which could be linked to NF-κB and JNK signaling.


Assuntos
Maneb , Praguicidas , Difosfato de Adenosina/metabolismo , Animais , Apoptose , Caspase 3/metabolismo , Celecoxib/metabolismo , Celecoxib/farmacologia , Ciclo-Oxigenase 2/metabolismo , Ciclo-Oxigenase 2/farmacologia , Inibidores de Ciclo-Oxigenase 2/metabolismo , Inibidores de Ciclo-Oxigenase 2/farmacologia , Citocromos c/metabolismo , Radicais Livres/metabolismo , Radicais Livres/farmacologia , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/farmacologia , Peróxidos Lipídicos/metabolismo , Peróxidos Lipídicos/farmacologia , NF-kappa B/metabolismo , Neutrófilos/metabolismo , Estresse Oxidativo , Paraquat/toxicidade , Praguicidas/farmacologia , Ratos , Ribose/metabolismo , Ribose/farmacologia , Superóxido Dismutase/metabolismo
3.
Pestic Biochem Physiol ; 187: 105188, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36127063

RESUMO

Pest management is challenged with resistant herbivores and problems regarding human health and environmental issues. Indeed, the greatest challenge to modern agriculture is to protect crops from pests and still maintain environmental quality. This study aimed to analyze by in silico, in vitro, and in vivo approaches to the feasibility of using the inhibitory protein extracted from mammals - Bovine Pancreatic Trypsin Inhibitor (BPTI) as a potential inhibitor of digestive trypsins from the pest Anticarsia gemmatalis and comparing the results with the host-plant inhibitor - Soybean Kunitz Trypsin Inhibitor (SKTI). BPTI and SKTI interacts with A. gemmatalis trypsin-like enzyme competitively, through hydrogen and hydrophobic bonds. A. gemmatalis larvae exposed to BPTI did not show two common adaptative mechanisms i.e., proteolytic degradation and overproduction of proteases, presenting highly reduced trypsin-like activity. On the other hand, SKTI-fed larvae did not show reduced trypsin-like activity, presenting overproduction of proteases and SKTI digestion. In addition, the larval survival was reduced by BPTI similarly to SKTI, and additionally caused a decrease in pupal weight. The non-plant protease inhibitor BPTI presents intriguing element to compose biopesticide formulations to help decrease the use of conventional refractory pesticides into integrated pest management programs.


Assuntos
Fabaceae , Mariposas , Praguicidas , Animais , Aprotinina/farmacologia , Agentes de Controle Biológico/farmacologia , Bovinos , Humanos , Hidrogênio/farmacologia , Larva , Mamíferos/metabolismo , Peptídeo Hidrolases/metabolismo , Praguicidas/farmacologia , Inibidores de Proteases/farmacologia , Soja/metabolismo , Tripsina , Inibidores da Tripsina/farmacologia
4.
Pestic Biochem Physiol ; 186: 105154, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35973759

RESUMO

Organophosphorus pesticides like Chlorpyrifos 48%EC were widely used to control agricultural pests. The present study aimed to evaluate the toxic effects of Chlorpyrifos 48%EC on B. alexandrina snails, the intermediate host of Schistosoma mansoni. After exposure of snails to serial concentrations to determine the LC50, thirty snails for each sublethal concentration (LC10 2.1 and LC25 5.6 mg/l) in each group were exposed for 24 h followed by another 24 h for recovery. After recovery random samples were collected from hemolymph and tissue to measure the impacts on Phagocytic index, histological, biochemical, and molecular parameters. The current results showed a toxic effect of Chlorpyrifos 48%EC on adult B. alexandrina snails after 24 h of exposure at LC50 9.6 mg/l. After exposure to the sub-lethal concentrations of this pesticide, it decreased the total number of hemocytes and the percentage of small cells, while increased the percentage of hyalinocytes. The granulocyte percentage was increased after exposure to LC10, while after LC25, it was decreased compared to the control group. Also, the light microscopical examination showed that some granulocytes have plenty of granules, vacuoles and filopodia. Some hyalinocytes were contained shrinked nuclei, incomplete cell division and forming pseudopodia. Besides, the phagocytic index of hemocytes was significantly increased than control in all treated groups. Also, these sub-lethal concentrations increased MDA and SOD activities, while, tissue NO, GST and TAC contents were significantly decreased after exposure. Levels of Testosterone (T) and Estradiol (E) were increased significantly after exposure compared with control group. The present results showed that the concentration of DNA and RNA was highly decreased after exposure to LC10, 25 than the control group. Therefore, B. alexandrina snails could be used as a bio monitor of the chemical pollution. Besides, this pesticide could reduce the transmission of schistosomiasis as it altered the biological system of these snails.


Assuntos
Biomphalaria , Clorpirifos , Moluscocidas , Praguicidas , Animais , Biomphalaria/genética , Clorpirifos/toxicidade , Hemócitos , Moluscocidas/toxicidade , Compostos Organofosforados/farmacologia , Praguicidas/farmacologia
5.
J Agric Food Chem ; 70(35): 10693-10707, 2022 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-35998302

RESUMO

Spiro compounds are biologically active organic compounds with unique structures, found in a wide variety of natural products and drugs. They do not readily lead to drug resistance due to their unique mechanisms of action and have, therefore, attracted considerable attention regarding pesticide development. Analyzing structure-activity relationships (SARs) and summarizing the characteristics of spiro compounds with high activity are crucial steps in the design and development of new pesticides. This review mainly summarizes spiro compounds with insecticidal, bactericidal, fungicidal, herbicidal, antiviral, and plant growth regulating functions to provide insight for the creation of new spiro compound pesticides.


Assuntos
Fungicidas Industriais , Inseticidas , Praguicidas , Compostos de Espiro , Desenho de Fármacos , Fungicidas Industriais/química , Fungicidas Industriais/farmacologia , Inseticidas/química , Inseticidas/farmacologia , Praguicidas/farmacologia , Compostos de Espiro/química , Compostos de Espiro/farmacologia , Relação Estrutura-Atividade
6.
Neurotoxicology ; 92: 131-155, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35914637

RESUMO

Investigation of the toxicity triggered by chemicals on the human brain has traditionally relied on approaches using rodent in vivo models and in vitro cell models including primary neuronal cultures and cell lines from rodents. The issues of species differences between humans and rodents, the animal ethical concerns and the time and cost required for neurotoxicity studies on in vivo animal models, do limit the use of animal-based models in neurotoxicology. In this context, human cell models appear relevant in elucidating cellular and molecular impacts of neurotoxicants and facilitating prioritization of in vivo testing. The SH-SY5Y human neuroblastoma cell line (ATCC® CRL-2266™) is one of the most used cell lines in neurosciences, either undifferentiated or differentiated into neuron-like cells. This review presents the characteristics of the SH-SY5Y cell line and proposes the results of a systematic review of literature on the use of this in vitro cell model for neurotoxicity research by focusing on organic environmental pollutants including pesticides, 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD), flame retardants, PFASs, parabens, bisphenols, phthalates, and PAHs. Organic environmental pollutants are widely present in the environment and increasingly known to cause clinical neurotoxic effects during fetal & child development and adulthood. Their effects on cultured SH-SY5Y cells include autophagy, cell death (apoptosis, pyroptosis, necroptosis, or necrosis), increased oxidative stress, mitochondrial dysfunction, disruption of neurotransmitter homeostasis, and alteration of neuritic length. Finally, the inherent advantages and limitations of the SH-SY5Y cell model are discussed in the context of chemical testing.


Assuntos
Poluentes Ambientais , Retardadores de Chama , Fluorcarbonetos , Neuroblastoma , Síndromes Neurotóxicas , Praguicidas , Dibenzodioxinas Policloradas , Adulto , Animais , Linhagem Celular Tumoral , Sobrevivência Celular , Criança , Poluentes Ambientais/toxicidade , Retardadores de Chama/farmacologia , Fluorcarbonetos/farmacologia , Humanos , Neuroblastoma/metabolismo , Síndromes Neurotóxicas/etiologia , Parabenos/farmacologia , Praguicidas/farmacologia , Dibenzodioxinas Policloradas/farmacologia
7.
ACS Appl Mater Interfaces ; 14(36): 41605-41617, 2022 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-36041169

RESUMO

The incorporation of green and sustainable nanomaterials in pesticide formation is an effective method to lower the use of conventional pesticides without adverse effects on productivity. Here pesticide Pickering emulsions stabilized by halloysite nanotubes (HNTs) were developed for low cost, less environmental pollution, low toxic effects, and better emulsion stability. HNTs were added to chlorantraniliprole (CAP) emulsions, and good stability was exhibited due to the adsorption and aggregation of HNTs at the interface of CAP oil droplets, forming a three-dimensional network structure that prevented the emulsion from aggregation. In addition, Spodoptera frugiperda was used as a pest model and corn was used as a plant model to explore the washout resistance, insecticidal effect, and biological safety of HNTs-CAP emulsion. After spraying emulsion on corn leaves and washing for 10 min, the HNTs-CAP emulsion (5 wt % HNTs) pesticide residue rate was 2.7 times that of pristine CAP emulsion. When the HNT dispersion concentration was 2 wt %, the larva mortality was 83%, which was 1.5 times that of the CAP emulsion group. These results demonstrated that HNTs-CAP emulsion showed good foliar adhesion, rainfall resistance, and insecticidal effect. The tubular clay-based nanopesticide formulations show potential applications in the control of crop pests with modern agriculture technology.


Assuntos
Inseticidas , Nanotubos , Praguicidas , Argila/química , Emulsões , Inseticidas/farmacologia , Nanotubos/química , Praguicidas/farmacologia , Chuva
8.
Molecules ; 27(16)2022 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-36014396

RESUMO

Fresh fruits and vegetables, being the source of important vitamins, minerals, and other plant chemicals, are of boundless importance these days. Although in agriculture, the green revolution was a milestone, it was accompanied by the intensive utilization of chemical pesticides. However, chemical pesticides have hazardous effects on human health and the environment. Therefore, increasingly stimulating toward more eco-friendly and safer alternatives to prevent postharvest losses and lead to improving the shelf life of fresh fruits and vegetables. Proposed alternatives, natural plant extracts, are very promising due to their high efficacy. The plant-based extract is from a natural source and has no or few health concerns. Many researchers have elaborated on the harmful effects of synthetic chemicals on human life. People are now much more aware of safety and health concerns than ever before. In the present review, we discussed the latest research on natural alternatives for chemical synthetic pesticides. Considering that the use of plant-based extracts from aloe vera, lemongrass, or neem is non-chemical by-products of the fruits and vegetable industry, they are proved safe for human health and may be integrated with economic strategies. Such natural plant extracts can be a good alternative to chemical pesticides and preservatives.


Assuntos
Praguicidas , Verduras , Agricultura , Frutas , Humanos , Praguicidas/farmacologia , Extratos Vegetais/farmacologia
9.
PLoS One ; 17(8): e0258631, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35951548

RESUMO

Pesticides are one of the main drivers of the worldwide amphibian decline. Their actual toxicity depends on a number of factors, like the species in focus or the developmental stage of exposed individuals. As ectothermic species, the metabolism of amphibians is influenced by ambient temperature. Therefore, temperature also affects metabolic rates and thus processes that might enhance or reduce toxic effects. Studies about the interactive effect of temperature and toxicity on amphibians are rare and deliver contrasting results. To investigate the temperature-dependent pesticide sensitivity of larvae of two European species we conducted acute toxicity tests for the viticultural fungicide Folpan® 500 SC with the active ingredient folpet at different temperatures (6°C, 11°C, 16°C, 21°C, 26°C). Sensitivity of Rana temporaria and Bufotes viridis was highly affected by temperature: early larvae (Gosner stage 20) were about twice more sensitive to Folpan® 500 SC at 6°C compared to 21°C. Next to temperature, species and developmental stage of larvae had an effect on sensitivity. The most sensitive individuals (early stages of R. temporaria at 6°C) were 14.5 times more sensitive than the least sensitive ones (early stages of B. viridis at 26°C). Our results raise concerns about typical ecotoxicological studies with amphibians that are often conducted at temperatures between 15°C and 20°C. We suggest that future test designs should be performed at temperatures that reflect the temperature range amphibians are exposed to in their natural habitats. Variations in the sensitivity due to temperature should also be considered as an uncertainty factor in upcoming environmental risk assessments for amphibians.


Assuntos
Fungicidas Industriais , Praguicidas , Animais , Bufonidae , Fungicidas Industriais/farmacologia , Humanos , Larva , Praguicidas/farmacologia , Ftalimidas , Rana temporaria , Temperatura
10.
ACS Appl Bio Mater ; 5(8): 4020-4027, 2022 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-35904971

RESUMO

Spodoptera frugiperda is a global pest that brings about great disasters to crops. Conventional pesticide formulations often suffer from poor water solubility, low stability, burst release, weak leaf adhesion, and low efficiency. To improve the insecticidal activity of pesticides, a stimuli-responsive controlled release pesticide delivery system (PDS) has attracted extensive attention in recent years. This paper reports a temperature-responsive controlled release PDS based on poly(N-isopropyl acrylamide) (PNIPAm)-modified indoxacarb (IDC)-loaded UiO-66-(COOH)2 (IDC@UiO-66-(COOH)2-PNIPAm) and studies its insecticidal activities against S. frugiperda. The UiO-66-(COOH)2 nanocarrier has an excellent pesticide loading performance, and the loading rate for IDC is 78.69%. The as-prepared PDS has good stability, temperature-responsive controllable release performance, and enhanced leaf affinity, so it can effectively improve the utilization rate of IDC. The insecticidal experiment indicates that the PDS has an enhanced control effect against S. frugiperda. In addition, biosafety analysis further verifies that the PDS exhibits no obvious negative effects on the germination of maize seeds and the growth of maize seedlings. In view of this, we believe that this PDS will have a broad application in the field of pesticide formulation innovation, pest management, and sustainable agricultural development.


Assuntos
Inseticidas , Estruturas Metalorgânicas , Praguicidas , Animais , Preparações de Ação Retardada/farmacologia , Inseticidas/farmacologia , Praguicidas/farmacologia , Ácidos Ftálicos , Spodoptera , Temperatura
11.
J Agric Food Chem ; 70(28): 8598-8608, 2022 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-35816608

RESUMO

The increasing evolution of insect resistance has made it challenging for traditional insecticides to control the bean aphid (Aphis craccivora Koch). To address this pending issue, a range of pyrido[1,2-a]pyrimidine mesoionic compounds containing benzo[b]thiophene were designed and synthesized. The biological activity test results of the target compounds indicated that they had moderate to outstanding insecticidal activity against the bean aphid (Aphis craccivora) and moderate insecticidal activity against the white-backed planthopper (Sogatella furcifera). Compound L14 exhibited significant insecticidal activity against A. craccivora, with an LC50 value of 1.82 µg/mL, which was superior to triflumezopyrim (LC50 = 4.76 µg/mL). The results of enzyme activity assay showed that compound L14 had a definite inhibitory effect on ATPase. Moreover, the proteomics and docking findings of compound L14 suggested that it may act on the central nervous system of aphids and interact with nicotinic acetylcholine receptors. Therefore, compound L14 is a potentially novel insecticide candidate for further utilization.


Assuntos
Afídeos , Inseticidas , Praguicidas , Receptores Nicotínicos , Animais , Inseticidas/farmacologia , Praguicidas/farmacologia , Tiofenos/farmacologia
12.
Int J Mol Sci ; 23(14)2022 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-35887136

RESUMO

The insulin receptor (IR) is a transmembrane protein that is activated by ligands in insulin signaling pathways. The IR has been considered as a novel therapeutic target for clinical intervention, considering the overexpression of its protein and A-isoform in multiple cancers, Alzheimer's disease, and Type 2 diabetes mellitus in humans. Meanwhile, it may also serve as a potential target in pest management due to its multiple physiological influences in insects. In this review, we provide an overview of the structural and molecular biology of the IR, functions of IRs in humans and insects, physiological and nonpeptide small molecule modulators of the IR, and the regulating mechanisms of the IR. Xenobiotic compounds and the corresponding insecticidal chemicals functioning on the IR are also discussed. This review is expected to provide useful information for a better understanding of human IR-related diseases, as well as to facilitate the development of novel small-molecule activators and inhibitors of the IR for use as medicines or pesticides.


Assuntos
Diabetes Mellitus Tipo 2 , Praguicidas , Diabetes Mellitus Tipo 2/tratamento farmacológico , Humanos , Insulina/metabolismo , Proteínas Substratos do Receptor de Insulina/metabolismo , Praguicidas/farmacologia , Receptor de Insulina/metabolismo
13.
Pestic Biochem Physiol ; 184: 105122, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35715060

RESUMO

The discovery of new scaffolds and targets for pesticides is still a huge challenge facing the sustainable development of modern agriculture. In recent years, quinazoline derivatives have achieved great progress in drug discovery and have attracted great attention. Quinazoline is a unique bicyclic scaffold with a variety of biological activities, which increases the possibilities and flexibility of structural modification, showing enormous appeal in the discovery of new pesticides. Therefore, the agricultural biological activities, structure-activity relationships (SAR), and mechanism of action of quinazoline derivatives in the past decade were reviewed systematically, with emphasis on SAR and mechanism. Then, we prospected the application of the quinazoline scaffold as a special structure in agricultural chemical discovery, hoping to provide new ideas for the rational design and mechanism of novel quinazoline agricultural chemicals in the future.


Assuntos
Praguicidas , Quinazolinas , Agroquímicos/farmacologia , Praguicidas/farmacologia , Quinazolinas/química , Quinazolinas/farmacologia , Relação Estrutura-Atividade
14.
J Agric Food Chem ; 70(25): 7653-7661, 2022 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-35698843

RESUMO

Pesticides play an important role in pest control. However, they can be limited due to low utilization efficiency, causing substantial losses to the environment and ecological damage. Nanotechnology is an active area of research regarding encapsulation of pesticides for sustainable pest control. Here, we developed intelligent formulations of avermectin (Av) quaternary ammonium chitosan surfactant (QACS) nanocapsules (i.e., Av-Th@QACS) with on-demand controlled release properties, toward ambient temperature and maximal synergistic biological activity of Av and QACS. The Av-Th@QACS regulated the quantity of pesticide release in accordance with the ambient temperature changes and, insofar as this release is a means of responding to variations in pest populations, maximized the synergistic activity. In addition, the Av-Th@QACS were highly adhesive to crop leaves as a result of the prolonged retention time on the crop leaves. Therefore, Av-Th@QACS exhibited greater control against aphids at 35 °C than at 15 and 25 °C. Compared with commercial formulations, Av-Th@QACS was more toxic at 35 °C and less toxic at 15 °C. Thus, researchers can apply Av-Th@QACS as intelligent nanopesticides with an on-demand, controlled release and synergistic biological activity and, in so doing, prolong pesticide duration and improve the utilization efficiency.


Assuntos
Compostos de Amônio , Quitosana , Nanocápsulas , Praguicidas , Preparações de Ação Retardada/farmacologia , Praguicidas/farmacologia , Compostos de Amônio Quaternário , Tensoativos
15.
Pest Manag Sci ; 78(10): 4072-4082, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35674449

RESUMO

BACKGROUND: Double-cropping is a common practice in vegetable plasticulture whereby a second crop is planted on the same plastic bed as the first crop. Root-knot nematodes (Meloidogyne spp.) are one of the major soilborne constraints in double-cropped vegetables due to nematode population build-up on the first crop. We evaluated the effect of fumigant and non-fumigant nematicides applied on the first crop, on nematode infection and yield of the second crop in 10 field trials between 2017 and 2020. Fumigants were chloropicrin (Pic100), chloropicrin +1,3-D (PicClor60), and non-fumigant nematicides were oxamyl (Vydate), fluensulfone (Nimitz), fluopyram (Velum) and fluazaindolizine (Salibro). The first crop was tomato and double crops were cucumber, squash, zucchini, and cantaloupe. RESULTS: Fumigation with chloropicrin on the first crop increased root-knot nematode damage on the double-crop at the end of the season in seven trials, while the opposite was noted in one trial, and no difference was noted in two trials. Fumigation with chloropicrin+1,3-D resulted in root-knot nematode damage less than chloropicrin but more than non-fumigated plots. Cucurbit yield was greater in non-fumigated beds in four trials, and in chloropicrin-treated beds in two trials. Fluensulfone reduced root-knot nematode damage on the second crop in five out of 10 trials. CONCLUSION: Our results indicate that chloropicrin applied on the tomato crop may lead to increased root-knot nematode damage on the double crop. More research is needed to understand the processes behind this, but it is possibly related to a reduction in natural nematode soil suppressiveness due to the broad-spectrum fungicidal activity of chloropicrin. © 2022 Society of Chemical Industry.


Assuntos
Hidrocarbonetos Clorados , Lycopersicon esculentum , Praguicidas , Tylenchoidea , Animais , Antinematódeos/farmacologia , Fumigação , Hidrocarbonetos Clorados/toxicidade , Praguicidas/farmacologia
16.
Parasit Vectors ; 15(1): 213, 2022 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-35710443

RESUMO

BACKGROUND: Agricultural pesticides may exert strong selection pressures on malaria vectors during the aquatic life stages and may contribute to resistance in adult mosquitoes. This could reduce the performance of key vector control interventions such as indoor-residual spraying and insecticide-treated nets. The aim of this study was to investigate effects of agrochemicals on susceptibility and fitness of the malaria vectors across farming areas in Tanzania. METHODS: An exploratory mixed-methods study was conducted to assess pesticide use in four villages (V1-V4) in south-eastern Tanzania. Anopheles gambiae (s.l.) larvae were collected from agricultural fields in the same villages and their emergent adults examined for insecticide susceptibility, egg-laying and wing lengths (as proxy for body size). These tests were repeated using two groups of laboratory-reared An. arabiensis, one of which was pre-exposed for 48 h to sub-lethal aquatic doses of agricultural pesticides found in the villages. RESULTS: Farmers lacked awareness about the linkages between the public health and agriculture sectors but were interested in being more informed. Agrochemical usage was reported as extensive in V1, V2 and V3 but minimal in V4. Similarly, mosquitoes from V1 to V3 but not V4 were resistant to pyrethroids and either pirimiphos-methyl or bendiocarb, or both. Adding the synergist piperonyl butoxide restored potency of the pyrethroids. Pre-exposure of laboratory-reared mosquitoes to pesticides during aquatic stages did not affect insecticide susceptibility in emergent adults of the same filial generation. There was also no effect on fecundity, except after pre-exposure to organophosphates, which were associated with fewer eggs and smaller mosquitoes. Wild mosquitoes were smaller than laboratory-reared ones, but fecundity was similar. CONCLUSIONS: Safeguarding the potential of insecticide-based interventions requires improved understanding of how agricultural pesticides influence important life cycle processes and transmission potential of mosquito vectors. In this study, susceptibility of mosquitoes to public health insecticides was lower in villages reporting frequent use of pesticides compared to villages with little or no pesticide use. Variations in the fitness parameters, fecundity and wing length marginally reflected the differences in exposure to agrochemicals and should be investigated further. Pesticide use may exert additional life cycle constraints on mosquito vectors, but this likely occurs after multi-generational exposures.


Assuntos
Anopheles , Inseticidas , Malária , Praguicidas , Piretrinas , Agricultura , Animais , Resistência a Inseticidas , Inseticidas/farmacologia , Malária/prevenção & controle , Controle de Mosquitos/métodos , Mosquitos Vetores , Praguicidas/farmacologia , Piretrinas/farmacologia , Tanzânia
17.
Neotrop Entomol ; 51(4): 600-612, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35680781

RESUMO

Entomopathogens (EPFs) are potential alternatives to chemical insecticides for managing Bemisia tabaci (Genn.), an invasive pest of the cotton crop. EPFs alone may not always provide enough insect pest control, but combining EPFs with pesticides, provided both components are compatible, can make an integrated pest management program considerably more effective. Hence, the bioefficacy of EPFs against whitefly, their compatibility with pesticides, and the factors responsible for determining compatibility were studied. The highest nymphal mortality was recorded with the Beauveria bassiana strains Bb-4511 (95.1%) and Bb-4565 (89.9%), and Metarhizium anisopliae Ma-1299 (86.7%) at 1 × 106 conidia ml-1. Lower LC50 values were observed for Cordyceps javanica Cj-089 and Bb-4511, 0.2 × 104 and 0.5 × 104 conidia ml-1, respectively. The toxicity index values in insecticide sensitivity assays ranged from 19.4 to 119.6% among all the EPFs. Comparatively, all the EPFs except Bb-4543 and Bb-4565 showed compatible to moderately toxic reactions to neonicotinoids and spinosyns. Organophosphates (ethion) and pyrethrins (bifenthrin) were toxic to very toxic to all the EPFs except Bb-4511, Fv-083, and Ma-1299. Cj-102 and Cj-089 were compatible with 50% of the average recommended dose of bifenthrin and ethion, and the average recommended dose for the field application of neonicotinoids and spinosyns. Principal component analysis showed that spore production and toxicity index values correlate with each other and are responsible for determining the EPF compatibility with insecticides. The EPF spore production and toxicity index are important factors for determining chemical compatibility. Compatible EPFs can be used individually or in combination as promising and compatible biological alternatives to insecticides in the management of whitefly in cotton.


Assuntos
Hemípteros , Inseticidas , Praguicidas , Animais , Inseticidas/farmacologia , Neonicotinoides , Ninfa , Controle Biológico de Vetores , Praguicidas/farmacologia , Esporos Fúngicos
18.
Environ Sci Technol ; 56(13): 9379-9386, 2022 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-35704902

RESUMO

Despite regulations and improved design, pesticides remain ubiquitous in the environment at relatively low, trace concentrations. To understand how prolonged exposure to trace pesticide concentrations impacts vertebrate brain development and behavior, we raised larval amphibians (northern leopard frogs, Lithobates pipiens) in 0, 1, or 10 µg/L of the organophosphorus pesticide chlorpyrifos (CPF) from hatching to metamorphosis. Tadpoles exposed to 1 µg/L CPF, but not 10 µg/L CPF, had changes in relative brain mass, relative telencephalon shape, and behavioral responses to a novel visual cue. Tadpoles exposed to 10 µg/L CPF had altered behavioral responses to predator-associated olfactory cues. After metamorphosis, frogs raised in 1 µg/L CPF, but not 10 µg/L CPF, had changes in the shape of their optic tectum and medulla. Thus, we provide robust evidence that even trace, yet ecologically realistic, concentrations of CPF have neurodevelopmental and behavioral effects that carry over to later life-history stages, further emphasizing the potent effects of trace levels of CPF on vertebrate development. Also, some but not all effects were nonmonotonic, meaning that effects were evident at the lowest but not at the higher concentration of CPF.


Assuntos
Clorpirifos , Inseticidas , Praguicidas , Animais , Anuros , Encéfalo , Clorpirifos/toxicidade , Larva , Compostos Organofosforados , Praguicidas/farmacologia
19.
Microbiol Res ; 262: 127083, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35696796

RESUMO

The lagoons are fragile ecosystems used by several species as a refuge and breeding area, and it is also a place where certain communities practice fishing activity. With increasing urbanization around this ecosystem, pesticides used in agriculture and untreated urban wastewater are drained into the river basin, resulting in the dispersion of organic matter and antifungals used by the population and farmers. These may favor the selection of resistant pathogens directly into the environment, a concern since several fungi have emerged as pathogens in the last decades. In this study, we investigated the presence in an impacted lagoon by potentially resistant yeasts to antifungal agents. We evaluated their capacity for producing extracellular enzymes that could act as virulence factors. Water samples from the Tramandaí lagoon were analyzed for the presence of pesticides using the SPE-LC-ESI-MS/MS. Tricyclazole, carbendazim, azoxystrobin, thiabendazole, and tebuconazole were found. Twenty-eight yeast species were isolated, including the multidrug-resistant Candida haemulonii, and species with high minimal inhibitory concentrations (MICs) for clinical antifungal agents. Around 93% of the isolates had MIC values above the resistance breakpoints established for Candida species for at least two antifungal agents. And 27% had high MICs values for fluconazole, terbinafine, amphotericin B, and caspofungin. Tebuconazole MICs values were highly associated with MICs for fluconazole, terbinafine, and amphotericin B, and significant correlations between high MICs for antifungal agents and enzyme production were found. The results indicated that the lagoon is a reservoir of resistance genes and a potential source for fungal infection, highlighting the importance of the One Health approach and the integrated vision of the ecosystem when managing these environments.


Assuntos
Antifúngicos , Praguicidas , Anfotericina B/farmacologia , Antifúngicos/farmacologia , Farmacorresistência Fúngica , Ecossistema , Fluconazol/farmacologia , Testes de Sensibilidade Microbiana , Praguicidas/farmacologia , Espectrometria de Massas em Tandem , Terbinafina , Leveduras
20.
J Agric Food Chem ; 70(21): 6377-6384, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35584200

RESUMO

In an effort to develop novel molecules with suitable insecticidal activities, 23,24-alkene-avermectin B2a derivatives have been synthesized via a one-pot multistep reaction using avermectin B2a, a byproduct of avermectin fermentation, as a starting material. All products and intermediates were characterized by 1H NMR, 13C NMR, and high-resolution mass spectrometry. Bioassay results showed that the LC50 values of compounds 4 and 9 against Meloidogyne incognita were 0.63 and 0.50 mg/L, respectively, similar to that of avermectin (0.46 mg/L). Importantly, the LC50 values of compound 9 against Tetranychus cinnabarinus and Mythimna separate were 0.0067 and 0.047 mg/L, respectively, superior to that of avermectin. Through field experiments, it could be found that spraying 0.25% water-dispersible granules of compound 9 345 g ha-1 could effectively control M. incognita outbreaks, with an efficacy of 84.9%. Combined with toxicity experiments, it could be further inferred that compound 9 may be useful as a low-toxicity pesticide. In summary, we efficiently synthesized a new B2a derivative as a potential pesticide and offered an important way for improving the utilization efficiency of avermectin fermentation products. In doing so, the environmental pollution associated with fermentation byproducts may be greatly reduced, potentially enabling a sustainable avermectin fermentation process.


Assuntos
Inseticidas , Praguicidas , Tylenchoidea , Animais , Fermentação , Inseticidas/farmacologia , Ivermectina/análogos & derivados , Praguicidas/farmacologia
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