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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 -
Spectrochimica Acta. Part A, Molecular... Aug 2023Phosmet is a phthalimide derived broad spectrum organophosphate pesticide which is vastly used across the globe to protect several ornamental or horticulture crops. The...
Phosmet is a phthalimide derived broad spectrum organophosphate pesticide which is vastly used across the globe to protect several ornamental or horticulture crops. The toxicity of phosmet is of utmost concern because of its direct effect on the nervous system of the victim after exposure. The mechanism of phosmet toxicity was explored by the interaction with the model blood protein which is hemoglobin. Bovine Hemoglobin (BHb) is a major protein of red blood cells (RBCs) that plays an important role in the exchange of gases for respiration and ensures adequate oxygen supply to tissues for oxygenation. In the current study, the interaction of BHb with phosmet was revealed using various spectroscopic techniques. Circular dichroism (CD) and Fourier transform infrared spectroscopy (FTIR) studies of BHb in the presence of phosmet showed secondary structural changes in the protein post binding, Fluorescence study shows the involvement of the dynamic quenching predominantly, Van't Hoffs thermodynamic study showed negative enthalpy value and free energy change and negative entropy change that revealed the involvement of hydrogen bonding and van der Waal forces predominantly further revealing spontaneous nature of binding interaction. The shift in Ultraviolet-visible spectra also revealed the nature of the interaction. In-silico study finally deduced the involvement of hydrogen bonding and polar interaction. The study inferred the moderate interaction of BHb with phosmet.
Topics: Phosmet; Molecular Docking Simulation; Protein Binding; Thermodynamics; Hemoglobins; Circular Dichroism; Binding Sites; Spectrometry, Fluorescence; Serum Albumin, Bovine; Spectrophotometry, Ultraviolet
PubMed: 37001261
DOI: 10.1016/j.saa.2023.122630 -
Food and Chemical Toxicology : An... Sep 2020Data on the bioactivation of Phosmet (Pho), a phthalimide-derived organophosphate pesticide (OPT), to the neurotoxic metabolite Phosmet-oxon (PhOx) in human are not...
Data on the bioactivation of Phosmet (Pho), a phthalimide-derived organophosphate pesticide (OPT), to the neurotoxic metabolite Phosmet-oxon (PhOx) in human are not available. The characterization of the reaction in single human recombinant CYPs evidenced that the ranking of the intrinsic clearances was: 2C18>2C19>2B6>2C9>1A1>1A2>2D6>3A4>2A6. Considering the average human hepatic content, CYP2C19 contributed for the great majority (60%) at relevant exposure concentrations, while CYP2C9 (33%) and CYP3A4 (31%) were relevant at high substrate concentration. The dose-dependent role of the active isoforms was confirmed in human liver microsomes by using selective CYP inhibitors. This prominent role of CYP2C in oxon formation was not shared by other OPTs. The pre-systemic Pho bioactivation measured in human intestinal microsomes was relevant accounting for ¼ of that measured in the liver showing two reaction phases catalysed by CYP2C and CYP3A4. Phosmet efficiently inhibited CPF bioactivation and detoxication, with Ki values (≈30 μM) relevant to pesticide concentrations achievable in the human liver, while the opposite is unlikely (Ki ≈ 160 μM) at the actual exposure levels, depending on the peculiar isoform-specific Pho bioactivation. Kinetic information in humans can support the development of quantitative in vitro/in vivo extrapolation and in silico models for risk assessment refinement for single and multiple pesticides.
Topics: Chlorpyrifos; Cytochrome P-450 Enzyme System; Drug Interactions; Gene Expression Regulation, Enzymologic; Humans; Insecticides; Isoenzymes; Liver; Molecular Structure; Phosmet; Risk Assessment
PubMed: 32590074
DOI: 10.1016/j.fct.2020.111514 -
Acta Crystallographica. Section E,... Jul 2010In the title compound, C(11)H(12)NO(4)PS(2), the dihedral angle between the phthalimidyl ring plane and the PS(2) plane of the phospho-rodithio-ate group is...
In the title compound, C(11)H(12)NO(4)PS(2), the dihedral angle between the phthalimidyl ring plane and the PS(2) plane of the phospho-rodithio-ate group is 60.41 (3)°. In the crystal structure, weak inter-molecular C-H⋯O hydrogen bonds and S⋯S inter-actions [3.3825 (9) Å] contribute to the stabilization of the packing.
PubMed: 21588425
DOI: 10.1107/S1600536810029338 -
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 -
Journal of Food Science Oct 2007Phosmet-adapted bacteria isolated from lowbush blueberries (Vaccinium angustifolium) were evaluated for their ability to degrade phosmet on blueberry fruit and in...
Phosmet-adapted bacteria isolated from lowbush blueberries (Vaccinium angustifolium) were evaluated for their ability to degrade phosmet on blueberry fruit and in minimal salt solutions. Microbial metabolism of phosmet by isolates of Enterobacter agglomerans and Pseudomonas fluorescens resulted in significant reductions (P < 0.05; 33.8%) in phosmet residues on blueberry fruit. Degradation was accompanied by microbial proliferation of phosmet-adapted bacteria. Preferential utilization of phosmet as a carbon source was investigated in minimal salt solutions inoculated with either E. agglomerans or P. fluorescens and supplemented with phosmet or phosmet and glucose. Microbial degradation concurrent with the proliferation of P. fluorescens was similar in both liquid systems, indicative of preferential utilization of phosmet as an energy substrate. E. agglomerans exhibited the ability to degrade phosmet as a carbon source, yet in the presence of added glucose, phosmet degradation occurred within the 1st 24 h only followed by total population mortality resulting in no appreciable degradation. Characteristic utilization of glucose by this isolate suggests a possible switch in carbon substrate utilization away from phosmet, which resulted in toxicity from the remaining phosmet. Overall, microbial metabolism of phosmet as an energy source resulted in significant degradation of residues on blueberries and in minimal salt solutions. Thus, the role of adapted strains of E. agglomerans and P. fluorescens in degrading phosmet on blueberries represents an extensive plant-microorganism relationship, which is essential to determination of phosmet persistence under pre- and postharvest conditions.
Topics: Blueberry Plants; Consumer Product Safety; Enterobacter; Food Microbiology; Humans; Insecticides; Pesticide Residues; Phosmet; Pseudomonas fluorescens
PubMed: 17995608
DOI: 10.1111/j.1750-3841.2007.00466.x -
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 -
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 -
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 -
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