-
Spectrochimica Acta. Part A, Molecular... Jan 2021Phosmet exerts its neurotoxicity by inhibiting acetylcholinesterase that catalyzes the degradation of acetylcholine (a neurotransmitter). Serum proteins are known to...
Phosmet exerts its neurotoxicity by inhibiting acetylcholinesterase that catalyzes the degradation of acetylcholine (a neurotransmitter). Serum proteins are known to influence the biodistribution of various endogenous and exogenous compounds. In the present study, the binding interactions of phosmet with bovine serum albumin (BSA) was investigated to determine the free concentration of phosmet for its neurotoxicity. The binding mechanism was studied using fluorescence, UV-Vis absorption spectroscopy, circular dichroism (CD), and molecular docking techniques. UV-Vis absorption data showed an increase in absorbance of BSA upon binding with phosmet with a slight red-shift in the peak around 280 nm. Intrinsic fluorescence of BSA was quenched in the presence of phosmet. The quenching was observed to be inversely correlated to the temperature that indicated the formation of ground state non-fluorescent complex (static quenching). Binding constant values and n values for the binding of phosmet with BSA at three different temperatures confirmed non-covalent binding interactions with a single set of equivalent binding sites. Thermodynamic parameters ∆G (-137.40 ± 3.58 kJ mol); ΔH (-16.33 ± 5.28 kJ mol) and ΔS(-469 ± 12.45 kJ mol) confirmed that the binding was spontaneous and non-covalent interactions like electrostatic, hydrogen bonding and van der Waals forces played an important role in the binding. The CD data indicated the conformational change in BSA upon binding with phosmet which resulted in a change in the melting temperature. Molecular docking presented the binding model for BSA-phosmet complex and displayed that non-covalent interactions played a significant role in the binding mechanism.
Topics: Binding Sites; Circular Dichroism; Molecular Docking Simulation; Phosmet; Protein Binding; Serum Albumin, Bovine; Spectrometry, Fluorescence; Spectrophotometry, Ultraviolet; Thermodynamics; Tissue Distribution
PubMed: 32829155
DOI: 10.1016/j.saa.2020.118803 -
Toxicology Research Oct 2021Phosmet is a non-systemic organophosphorus insecticide exerting its toxicity by inhibiting acetylcholinesterase upon entering the body via contact, ingestion and...
Phosmet is a non-systemic organophosphorus insecticide exerting its toxicity by inhibiting acetylcholinesterase upon entering the body via contact, ingestion and inhalation. Data regarding its sublethal effects on fish are limited, and therefore, with this study it was aimed to investigate the effects of phosmet on liver and brain tissues of juvenile following 24, 48, 72 and 96 h of exposure to 5, 25 and 50 μg/l concentrations. Pesticide treatment caused notable decrease in the levels of serum glucose, protein and cholesterol, whereas there was prominent elevation in the activities of alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase. Anticholinesterase activity of phosmet was observed in brain tissue reaching maximum of 46%. In both tissues, increase in the activities of superoxide dismutase, catalase and glutathione peroxidase and level of glutathione was accompanied by elevated thiobarbituric acid reactive substances level. Our results clearly indicate the modulatory effect of phosmet on acetylcholinesterase activity and its potency to provoke oxidative stress condition. The determined alteration in alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase activities indicates hepatotoxic potential of pesticide; meanwhile, obtained hypoglycaemia and hypoproteinaemia are evaluated as adaptive responses to handle the stress to survive.
PubMed: 34733483
DOI: 10.1093/toxres/tfab084 -
Environment International Jan 2023Pesticide exposure has been associated with adverse health effects. We evaluated relationships between proximity to agricultural insecticide applications and...
BACKGROUND
Pesticide exposure has been associated with adverse health effects. We evaluated relationships between proximity to agricultural insecticide applications and insecticides in household dust, accounting for land use and wind direction.
METHODS
We measured concentrations (ng/g) of nine insecticides in carpet-dust samples collected from 598 California homes. Using a geographic information system (GIS), we integrated the California Pesticide Use Reporting (CPUR) database to estimate agricultural use within residential buffers with radii of 0.5 to 4 km. We calculated the density of use (kg/km) during 30-, 60-, 180-, and 365-day periods prior to dust collection and evaluated relationships between three density metrics (CPUR unit-based, agricultural land area adjusted, and average daily wind direction adjusted) and dust concentrations. We modeled natural-log transformed concentrations using Tobit regression for carbaryl, chlorpyrifos, cypermethrin, diazinon, and permethrin. Odds of detection were modeled with logistic regression for azinphos-methyl, cyfluthrin, malathion, and phosmet. We adjusted for season, year, occupation, and home/garden uses.
RESULTS
Chlorpyrifos use within 1-4 km was associated with 1 to 2-times higher dust concentrations in both the 60- and 365-day periods. Carbaryl applications within 2-4 km of homes 60-days prior to dust collection were associated with 3 to 7-times higher concentrations and the 4 km trend was strongest using the wind-adjusted metric (p-trend = 0.04). For diazinon, there were 2-times higher concentrations for the 60-day metrics in the 2 km buffer and for the CPUR and wind-adjusted metrics within 4 km. Cyfluthrin, phosmet, and azinphos-methyl applications within 4 km in the prior 365-days were associated with 2-, 6-, and 3-fold higher odds of detection, respectively.
CONCLUSIONS
Agricultural use of six of the nine insecticides within 4 km is an important determinant of indoor contamination. Our findings demonstrated that GIS-based metrics for quantifying potential exposure to fugitive emissions from agriculture should incorporate tailored distances and time periods and support wind-adjustment for some, but not all insecticides.
Topics: Insecticides; Chlorpyrifos; Diazinon; Azinphosmethyl; Environmental Exposure; Phosmet; Carbaryl; Agriculture; Pesticides; Dust
PubMed: 36493610
DOI: 10.1016/j.envint.2022.107657 -
Micromachines Mar 2023Here, a molecular imprinting technique was employed to create an SPR-based nanosensor for the selective and sensitive detection of organophosphate-based coumaphos, a...
Here, a molecular imprinting technique was employed to create an SPR-based nanosensor for the selective and sensitive detection of organophosphate-based coumaphos, a toxic insecticide/veterinary drug often used. To achieve this, UV polymerization was used to create polymeric nanofilms using -methacryloyl-l-cysteine methyl ester, ethylene glycol dimethacrylate, and 2-hydroxyethyl methacrylate, which are functional monomers, cross-linkers, and hydrophilicity enabling agents, respectively. Several methods, including scanning electron microscopy (SEM), atomic force microscopy (AFM), and contact angle (CA) analyses, were used to characterize the nanofilms. Using coumaphos-imprinted SPR (CIP-SPR) and non-imprinted SPR (NIP-SPR) nanosensor chips, the kinetic evaluations of coumaphos sensing were investigated. The created CIP-SPR nanosensor demonstrated high selectivity to the coumaphos molecule compared to similar competitor molecules, including diazinon, pirimiphos-methyl, pyridaphenthion, phosalone, -2,4(dimethylphenyl) formamide, 2,4-dimethylaniline, dimethoate, and phosmet. Additionally, there is a magnificent linear relationship for the concentration range of 0.1-250 ppb, with a low limit of detection (LOD) and limit of quantification (LOQ) of 0.001 and 0.003 ppb, respectively, and a high imprinting factor (I.F.4.4) for coumaphos. The Langmuir adsorption model is the best appropriate thermodynamic approach for the nanosensor. Intraday trials were performed three times with five repetitions to statistically evaluate the CIP-SPR nanosensor's reusability. Reusability investigations for the two weeks of interday analyses also indicated the three-dimensional stability of the CIP-SPR nanosensor. The remarkable reusability and reproducibility of the procedure are indicated by an RSD% result of less than 1.5. Therefore, it has been determined that the generated CIP-SPR nanosensors are highly selective, rapidly responsive, simple to use, reusable, and sensitive for coumaphos detection in an aqueous solution. An amino acid, which was used to detect coumaphos, included a CIP-SPR nanosensor manufactured without complicated coupling methods and labelling processes. Liquid chromatography with tandem mass spectrometry (LC/MS-MS) studies was performed for the validation studies of the SPR.
PubMed: 37420940
DOI: 10.3390/mi14040707 -
Analytica Chimica Acta Nov 2023The residues of pesticides and antibiotics have always been a major concern in agriculture and food safety. In order to provide a new method for the rapid detection of...
Sensitive fluorescent detection of phosmet and chlortetracycline in animal-derived food samples based on a water-stable Cd(II) chain-based zwitterionic metal-organic framework.
The residues of pesticides and antibiotics have always been a major concern in agriculture and food safety. In order to provide a new method for the rapid detection of organophosphorus pesticides and antibiotics, a novel Cd(II) chain-based zwitterionic metal-organic framework MOF 1 with high sensitivity fluorescence sensing performance was successfully synthesized. A series of researches showed that the water- and pH-stable bifunctional MOF 1 has a great ability to detect phosmet (PSM) and chlortetracycline (CTC) in water through fluorescence quenching effect, with high detection sensitivity, low detection limits (0.0124 μM and 0.0131 μM), short response time (40 s) and reusability. Practical application results revealed that MOF 1 could detect PSM and CTC in milk, beef, chicken and egg samples, with satisfactory recoveries (95.2%-103.7%). As a novel fluorescence probe, MOF 1, is known the first case that can detect PSM in animal-derived samples, and the first dual-function material capable of detecting PSM and CTC. Mechanism studies displayed that competitive absorption and photoinduced electron transfer clearly authenticate the high quenching performance of the material.
Topics: Animals; Cattle; Chlortetracycline; Metal-Organic Frameworks; Phosmet; Cadmium; Water; Organophosphorus Compounds; Pesticides; Anti-Bacterial Agents
PubMed: 37858547
DOI: 10.1016/j.aca.2023.341850 -
EFSA Journal. European Food Safety... Mar 2021The conclusions of the EFSA following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State, Spain, and... (Review)
Review
The conclusions of the EFSA following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State, Spain, and co-rapporteur Member State, Greece, for the pesticide active substance phosmet and the assessment of applications for maximum residue levels (MRLs) are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012, as amended by Commission Implementing Regulation (EU) No 2018/1659. The conclusions were reached on the basis of the evaluation of the representative uses of phosmet as an insecticide on citrus fruits, pome fruits, peaches/nectarines and potatoes (field uses). The reliable end points, appropriate for use in regulatory risk assessment, are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are identified.
PubMed: 33747228
DOI: 10.2903/j.efsa.2021.6237 -
PeerJ 2024The use of pesticides to control pests, weeds, and diseases or to regulate plant growth is indispensable in agricultural production. However, the excessive use of these...
The use of pesticides to control pests, weeds, and diseases or to regulate plant growth is indispensable in agricultural production. However, the excessive use of these chemicals has led to significant concern about their potential negative impacts on health and the environment. Phosmet is one such pesticide that is commonly used on plants and animals against cold moth, aphids, mites, suckers, and fruit flies. Here, we investigated the effects of phosmet on a model organism, using acute and chronic toxicity endpoints such as lethality, mobility, genotoxicity, reproduction, and gene expression. We performed survival experiments in six-well plates at seven different concentrations (0.01, 0.1, 1, 10, 25, 50, 100 μM) as well as the control in three replicates. We observed statistically significant mortality rates at 25 µM and above upon 24 h of exposure, and at 1 µM and above following 48 h of exposure. Genotoxicity analysis, reproduction assay and qPCR analysis were carried out at concentrations of 0.01 and 0.1 μM phosmet as these concentrations did not show any lethality. Comet assay showed that exposure to phosmet resulted in significant DNA damage in the cells. Interestingly, 0.1 μM phosmet produced more offspring per adult compared to the control group indicating a hormetic response. Gene expression profiles demonstrated several genes involved in different physiological pathways, including oxidative stress, detoxification, immune system, hypoxia and iron homeostasis. Taken together, our results indicate that phosmet has negative effects on in a dose- and time-dependent manner and could also induce lethal and physiological toxicities to other aquatic organisms.
Topics: Animals; Phosmet; Daphnia magna; Reproduction; Pesticides; Drosophila; Gene Expression
PubMed: 38436013
DOI: 10.7717/peerj.17034 -
Soft Matter Sep 2022Active vesicles, constructed through the confinement of self-propelled particles (SPPs) inside a lipid membrane shell, exhibit a large variety of non-equilibrium shapes,...
Active vesicles, constructed through the confinement of self-propelled particles (SPPs) inside a lipid membrane shell, exhibit a large variety of non-equilibrium shapes, ranging from the formation of local tethers and dendritic conformations, to prolate and bola-like structures. To better understand the behavior of active vesicles, we perform simulations of membranes modelled as dynamically triangulated surfaces enclosing active Brownian particles. A systematic analysis of membrane deformations and SPP clustering, as a function of SPP activity and volume fraction inside the vesicle is carried out. Distributions of membrane local curvature, and the clustering and mobility of SPPs obtained from simulations of active vesicles are analysed. There exists a feedback mechanism between the enhancement of membrane curvature, the formation of clusters of active particles, and local or global changes in vesicle shape. The emergence of active tension due to the activity of SPPs can well be captured by the Young-Laplace equation. Furthermore, a simple numerical method for tether detection is presented and used to determine correlations between the number of tethers, their length, and local curvature. We also provide several geometrical arguments to explain different tether characteristics for various conditions. These results contribute to the future development of steerable active vesicles or soft micro-robots whose behaviour can be controlled and used for potential applications.
Topics: Lipid Bilayers; Molecular Conformation; Phosmet
PubMed: 36043635
DOI: 10.1039/d2sm00622g -
Food Chemistry May 2020There have been increasing concerns among consumers about pesticide residues in Oolong tea. This study aimed to establish surface-enhanced Raman scattering (SERS) method...
There have been increasing concerns among consumers about pesticide residues in Oolong tea. This study aimed to establish surface-enhanced Raman scattering (SERS) method for rapid measurement of chemical contaminants in Oolong tea. Synthesis of SERS substrate was achieved by synthesizing silver nanoparticles (AgNPs) via a reduction method. AgNPs were spherical and highly monodispersed, which created remarkable electromagnetic fields during SERS activities to measure phosmet in the methanol-water solution and Oolong tea. Partial least squares regression models were established to predict the concentrations of phosmet in the methanol-water solution (r = 0.934; slope = 0.880; RMSEP = 1.001 mg/L) and Oolong tea samples (r = 0.927; slope = 0.938; RMSEP = 1.157 mg/kg) with the detection limit of 0.1 mg/kg. The results indicate that SERS coupled with silver nanoparticles is a fast, sensitive, and reliable method for detection and characterization of pesticide contaminants in Oolong tea products.
Topics: Color; Least-Squares Analysis; Limit of Detection; Metal Nanoparticles; Pesticide Residues; Phosmet; Silver; Spectrum Analysis, Raman; Tea
PubMed: 31896459
DOI: 10.1016/j.foodchem.2019.126016 -
Transcriptome-Based Identification of Genes Responding to the Organophosphate Pesticide Phosmet in .Genes Oct 2021Organophosphate pesticides (OPPs) are one of the most widely used insecticides. OPPs exert their neurotoxic effects by inhibiting acetylcholine esterase (AChE). Most of...
Organophosphate pesticides (OPPs) are one of the most widely used insecticides. OPPs exert their neurotoxic effects by inhibiting acetylcholine esterase (AChE). Most of the gross developmental abnormalities observed in OPP-treated fish, on the other hand, may not be explained solely by AChE inhibition. To understand the overall molecular mechanisms involved in OPP toxicity, we used the zebrafish (ZF) model. We exposed ZF embryos to an OPP, phosmet, for 96 h, and then analyzed developmental abnormalities and performed whole transcriptome analysis. Phenotypic abnormalities, such as bradycardia, spine curvature, and growth retardation, were observed in phosmet-treated ZF (PTZF). Whole transcriptome analysis revealed 2190 differentially expressed genes (DEGs), with 822 and 1368 significantly up-and downregulated genes, respectively. System process and sensory and visual perception were among the top biological pathways affected by phosmet toxicity. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed significant enrichment of metabolic pathways, calcium signaling pathway, regulation of actin cytoskeleton, cardiac muscle contraction, drug metabolism-other enzymes, and phototransduction. Quantitative real-time PCR results of six DEGs agreed with the sequencing data expression profile trend. Our findings provide insights into the consequences of phosmet exposure in ZF, as well as an estimate of the potential risk of OPPs to off-target species.
Topics: Actin Cytoskeleton; Animals; Embryo, Nonmammalian; Gene Expression Profiling; Gene Expression Regulation, Enzymologic; Insecticides; Metabolic Networks and Pathways; Myocardium; Organophosphorus Compounds; Phosmet; Signal Transduction; Transcriptome; Water Pollutants, Chemical; Zebrafish
PubMed: 34828343
DOI: 10.3390/genes12111738