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The Science of the Total Environment Dec 2023L'Albufera Natural Park (Valencia, Spain) is a protected wetland of international significance that provides critical habitats to endemic and threatened bird and plant...
L'Albufera Natural Park (Valencia, Spain) is a protected wetland of international significance that provides critical habitats to endemic and threatened bird and plant species. This study aims to use multiple cross-validation techniques to generate an accurate estimation of the environmental risk of organic contaminants (OCs) in an internationally important coastal wetland, to identify compounds of concern and their potential sources and risk factors. Microporous polyethylene tube (MPT) passive samplers were deployed at 12 locations across L'Albufera Natural Park with concurrent grab samples collected. A subset of MPT samplers were also analysed by an additional laboratory in Australia to widen the range of contaminants and assess interlaboratory reproducibility of results. Forty-three pesticides, 20 pharmaceuticals and personal care products (PPCPs), 20 per-and polyfluoroalkyl substances (PFAS) and 4 organophosphorus flame retardants (OPFRs) were detected in the MPT samplers. The fungicides tebuconazole and difenoconazole were detected at the highest concentrations in passive samplers (maximum concentrations, 153 ng sampler and 106 ng sampler, respectively). Several other pesticides were detected in all locations (mean concentrations >1 ng sampler). The compounds fenamiphos, propyzamide, difenoconazole, propiconazole, metsulfuron methyl, sodium bis (perfluorohexyl) phosphinate (6:6 PFPiA), 6:2 fluorotelomer sulfonamide alkylbetaine (6:2 FTAB), 6:2 fluorotelomersulfonate (6:2 FTS), citalopram desmethyl and citalopram were reported in the wetland for the first time. Spatial distribution analysis revealed higher pesticide concentrations in the North of L'Albufera. A risk quotient (RQ) analysis showed that ibuprofen is of concern in the area. Overall, the MPT sampling approach is promising as a risk assessment tool for better understanding the transport and fate of OCs in protected areas.
PubMed: 37640071
DOI: 10.1016/j.scitotenv.2023.166594 -
Scientific Reports Jan 2023Reducing nematicide dose rates could be a useful strategy for mitigating their negative effects on health and the environment. In this study, enzymatic activities and...
Reducing nematicide dose rates could be a useful strategy for mitigating their negative effects on health and the environment. In this study, enzymatic activities and the parasitic ability of Meloidogyne incognita after exposure to sub-lethal concentrations (0.25, 1, 2, and 5 ppm) of ethoprophos, fenamiphos, and oxamyl were investigated. Although the tested concentrations did not show nematicidal properties in vitro, they reduced root galls by at least 30% at 0.25 ppm and up to 67% at 5 ppm in pots, besides disrupting nematode fertility. For all three nematicides at 2 ppm, a chemotaxis assay showed that ≤ 11% of the nematode population was successfully oriented to the host roots, compared to 44% in the control. Ethoprophos and fenamiphos at 5 ppm showed poor inhibitory effects on acetylcholinesterase (AChE) activity (5.6% and 12.5%, respectively). In contrast, the same nematicides were shown to be strong ATPase inhibitors, causing 82.4% and 82.8% inhibition, respectively. At the same concentration, oxamyl moderately inhibited AChE and ATPase-specific activities, the inhibition being 22.5% and 35.2%, respectively. This study suggests that the use of very low nematicide concentrations could be a promising strategy for nematode management. Furthermore, it has also highlighted the role of ATPases as a possible target site for suppressing nematode activity in the development of future nematicides.
Topics: Animals; Tylenchoidea; Acetylcholinesterase; Antinematodal Agents
PubMed: 36604555
DOI: 10.1038/s41598-022-27270-z -
Plants (Basel, Switzerland) Oct 2022Losses caused by phytoparasitic nematodes in crops depend directly on their soil densities at the start of the crop, so reducing their populations before planting is the...
Losses caused by phytoparasitic nematodes in crops depend directly on their soil densities at the start of the crop, so reducing their populations before planting is the main aim of nematological management. Efficacies in reducing soil populations of soil disinfestation methods, such as agrochemicals, botanicals, or biosolarization were estimated on multiple field trials conducted over fourteen years in intensive horticultural crops. Soil nematode populations were reduced by 87 to 78% after fumigation with 1,3-dichloropropene + chloropicrin and dimethyl-disulphide, respectively. Non-fumigant nematicides such as azadirachtin, dazomet, fenamiphos, fluopyram, fosthiazate, metam-sodium, and oxamyl showed efficacies ranging from 51 to 64%, whereas the efficacy of natural products, such as abamectin, garlic extracts, or essential oils was 41 to 48%. Biosolarization with chicken manure had an efficacy of 73%. An economic cost-benefit study of nematode management methods was performed for seven vegetable- pathosystems. Fumigation with 1,3-dichloropropene + chloropicrin and biosolarization with chicken manure were the only treatments able to reduce RKN populations above 1000 and 750 J2 per 100 cm of soil, respectively, to levels below the nematode economic damage threshold, keeping profitability. Fumigation was able to manage RKN soil densities up to 350 J2 per 100 cm of soil in most susceptible crops as aubergine or cucumber and up to 1000 J2 per 100 cm of soil for more tolerant crops, such as other cucurbits, pepper, or tomato. Other nematicidal treatments were not able to reduce RKN populations above 200-300 J2/100 cm of soil below the economic thresholds but were profitable when RKN densities were below the limits of 200-300 J2/100 cm of soil.
PubMed: 36297797
DOI: 10.3390/plants11202774 -
Chirality Aug 2022While not initially a focus or priority, in recent decades, an emphasis has been placed on the activity of individual enantiomers of widely used pesticides. Of...
While not initially a focus or priority, in recent decades, an emphasis has been placed on the activity of individual enantiomers of widely used pesticides. Of particular note are organophosphorus-based pesticides like fenamiphos and profenofos, as examples. This work explores the enantioselective high-performance liquid chromatography (HPLC) separations of seven such organophosphorus pesticides (OP's) on the library of immobilized polysaccharide-based chiral stationary phases (CSPs) with normal phase hexane/alcohol mixtures. Further exploration of the effect of mobile phase strength and temperature on several of the separations was performed using simple factorial design. Equivalent retention of the first eluting enantiomer of several combinations of temperature and mobile phase was compared for peak shape, selectivity, and resolution. Similarly, equivalent selectivity of several combinations of temperature and mobile phase was compared for peak shape, retention of the first eluting enantiomer, and resolution. The results of this study make available several new chiral separations of the OPs included in the work that were not previously documented, including separations on the three most recently commercialized phases, Chiralpak IH, IJ, and IK. Additionally, sufficient understanding was obtained to be able to predict the trade-off of resolution, analysis time, peak sharpness (and thus improve limit-of-detection [LOD]/limit-of-quantification [LOQ]), robustness, and convenience of conditions for further application optimization.
Topics: Chromatography, High Pressure Liquid; Organophosphates; Organophosphorus Compounds; Pesticides; Polysaccharides; Stereoisomerism
PubMed: 35642080
DOI: 10.1002/chir.23473 -
Saudi Journal of Biological Sciences May 2022Organic acids and plant extracts, which have a nemacidal action and may be used instead of nematicides that pollute the environment, are one way for controlling the...
Organic acids and plant extracts, which have a nemacidal action and may be used instead of nematicides that pollute the environment, are one way for controlling the pepper root-knot nematode. We provide in this study for a first time a new strategy for management (Kofoid and White) by using organic acids and plant extract compared to nematicides on four peppers cultivars (Super amarr, Super mard, Super noura and Werta) under greenhouse conditions compared to nematicides. This study aimed to evaluate 0.1% of organic acids (humic and salicylic acid) and 0.1% of extract on plant parameters of pepper varieties (Super amarr, Super mard, Super noura and Werta) and control of under greenhouse conditions compared to four nematicides (Oxamyl 24% SL, Fosthiazates 75% EC, Ethoprophos N40% EC and Fenamiphos 40% EC). Our data obtained four nematicides were more effectiveness than other treatments in reduced galls and egg masses of . Whilst, humic and salicylic acids have remarkably higher nematicidal activity than in all lines of pepper. Therefore, plant extract and organic acids may be used a best alternative of nematicides to control PPNs and caused the longitudinal growth of plant. Also, ultimately reduce environmental risk from nematicide pollution.
PubMed: 35355956
DOI: 10.1016/j.sjbs.2022.03.018 -
Saudi Journal of Biological Sciences Feb 2022Nemours effective management tactics were used to reduce world crop losses caused by plant-parasitic nematodes. Nowadays the metallic nanoparticles are easily developed...
Nemours effective management tactics were used to reduce world crop losses caused by plant-parasitic nematodes. Nowadays the metallic nanoparticles are easily developed with desired size and shape. Nanoparticles (NPs) technology becomes a recognized need for researchers. Ecofriendly and biosafe SiNPs are developed from microorganisms. Recently, silicon nanoparticles (SiNPs) have gained novel pesticide properties against numerous agricultural pests. This study assessed the biosynthesis of SiNPs from SM5. The obtained SiNPs were spherical with a size of 45 nm and a negative charge of -25.65. The nematocidal effect of SiNPs against egg hatching and second-stage juveniles (J2) of root-knot nematode (RKN) () was evaluated on eggplant, L. plants. , all tested SiNPs concentrations significantly ( ≤ 0.05) inhibited the percentage of egg hatching at a different time of exposure than control. Meanwhile, after 72 h, the percent mortality of J2 ranged from 87.00 % to 98.50 %, with SiNPs (100 and 200 ppm). The combination between SiNPs and the half-recommended doses (0.5 RD) of commercial nematicides namely, fenamiphos (Femax 40 % EC), nemathorin (Fosthiazate 10 % WG) , and fosthiazate (krenkel 75 % EC) confirmed the increase of egg hatching inhibition and J2 mortality after exposure to SiNPs (100 ppm) mixed with 0.5 RD of synthetic nematicides. The findings suggest that the combination between SiNPs, and 0.5 RD of nematicides reduced nematode reproduction, gall formation, egg masses on roots and final population of J2 in the soil. Therefore, improving the plant growth parameters by reducing the population.
PubMed: 35197760
DOI: 10.1016/j.sjbs.2021.10.013 -
Scientific Reports Feb 2022Aphelenchoides besseyi could cause great yield losses of rice and many economically important crops. Acetylcholinesterase (AChE) inhibitors were commonly used to manage...
Aphelenchoides besseyi could cause great yield losses of rice and many economically important crops. Acetylcholinesterase (AChE) inhibitors were commonly used to manage plant-parasitic nematodes. However, nematodes resistant to AChE inhibitors have been increasingly reported due to the extensive use of these chemicals. The current study was aimed to establish the correlation between fenamiphos (an AChE-inhibitor) sensitivities and acetylcholinesterase genes (ace) by analyzing two isolates of A. besseyi (designated Rl and HSF), which displayed differential sensitivities to fenamiphos. The concentrations of fenamiphos that led to the death of 50% (LD) of Rl and HSF were 572.2 ppm and 129.4 ppm, respectively. Three ace genes were cloned from A. besseyi and sequenced. Sequence searching and phylogenic analyses revealed that AChEs of R1 and HSF shared strong similarities with those of various vertebrate and invertebrate species. Molecular docking analysis indicated that AChEs-HSF had much higher affinities to fenamiphos than AChEs-R1. Quantitative reverse transcriptase-PCR analyses revealed that expression of three ace genes were downregulated in HSF but were upregulated in Rl after exposure to 100 ppm fenamiphos for 12 h. The results indicated that the expression of the ace genes was modulated in response to fenamiphos in different nematode strains. An increased expression of the ace genes might contribute to fenamiphos-insensitivity as seen in the Rl isolate.
Topics: Acetylcholinesterase; Animals; Cholinesterase Inhibitors; Dose-Response Relationship, Drug; Down-Regulation; Gene Expression; Lethal Dose 50; Molecular Docking Simulation; Nematoda; Organophosphorus Compounds; Up-Regulation
PubMed: 35132122
DOI: 10.1038/s41598-022-05998-y -
Scientific Reports Nov 2021Toxicity of organophosphorus compounds (OPs) remains a major public health concern due to their widespread use as pesticides and the existence of nerve agents. Their...
Toxicity of organophosphorus compounds (OPs) remains a major public health concern due to their widespread use as pesticides and the existence of nerve agents. Their common mechanism of action involves inhibition of enzymes acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) which are crucial for neurotransmission. Both chronic and acute poisoning by OPs can leave long-lasting health effects even when the patients are treated with standard medical therapy. Therefore, an increasing urgency exists to find more effective oxime reactivators for compounds which are resistant to reactivation, especially phosphoramidates. Here, we investigated in silico and in vitro interactions and kinetics of inhibition for human cholinesterases with four organophosphate pesticides-ethoprophos, fenamiphos, methamidophos and phosalone. Overall, ethoprophos and fenamiphos displayed higher potency as inhibitors for tested cholinesterases. Our results show that methamidophos-inhibited hAChE was more susceptible to reactivation than hAChE inhibited by fenamiphos by selected oximes. Molecular modelling enabled an evaluation of interactions important for specificity and selectivity of both inhibition and reactivation of cholinesterases. Two newly developed reactivators-bispyridinium triazole oxime 14A and zwitterionic oxime RS194B possess remarkable potential for further development of antidotes directed against pesticides and related phosphoramidate exposures, such as nerve agents tabun or Novichoks.
Topics: Acetylcholinesterase; Butyrylcholinesterase; Cholinesterase Inhibitors; GPI-Linked Proteins; Humans; Kinetics; Organophosphorus Compounds; Pesticides
PubMed: 34728713
DOI: 10.1038/s41598-021-00953-9 -
Food and Chemical Toxicology : An... Dec 2020Fenamiphos (FS) is a chiral organophosphate pesticide that is used to control nematodes in several crops. Enantioselective differences may be observed in FS activity,...
Fenamiphos (FS) is a chiral organophosphate pesticide that is used to control nematodes in several crops. Enantioselective differences may be observed in FS activity, bioaccumulation, metabolism, and toxicity. Humans may be exposed to FS through occupational and chronic (food, water, and environmental) exposure. FS may cause undesirable CYP450 pesticide-drug interactions, which may impact human health. Here, the CYP450 isoforms involved in enantioselective FS metabolism were identified, and CYP450 inhibition by rac-FS, (+)-FS, and (-)-FS was evaluated to obtain reliable information on enantioselective FS risk assessment in humans. CYP3A4 and CYP2E1 metabolized FS enantiomers, and CYP2B6 may participate in rac-FS metabolism. In addition, rac-FS, (+)-FS, and (-)-FS were reversible competitive CYP1A2, CYP2C19, and CYP3A4/5 inhibitors. High stereoselective inhibition potential was verified; rac-FS and (-)-FS strongly inhibited and (+)-FS moderately inhibited CYP1A2. Stereoselective differences were also detected for CYP2C19 and CYP3A4/5, which were strongly inhibited by rac-FS, (+)-FS, and (-)-FS. Our results indicated a high potential for CYP450 drug-pesticide interactions, which may affect human health. The lack of stereoselective research on the effect of chiral pesticides on the activity of CYP450 isoforms highlights the importance of assessing the risks of such pesticides in humans.
Topics: Cytochrome P-450 Enzyme Inhibitors; Cytochrome P-450 Enzyme System; Drug Interactions; Humans; Isoenzymes; Microsomes, Liver; Organophosphorus Compounds; Pesticides; Recombinant Proteins
PubMed: 33127494
DOI: 10.1016/j.fct.2020.111826 -
Journal of Nematology 2020The nematicidal activity of crudely milled powders of stems, leaves, and bulbs of , , , , , , , and on eggs and J2 population densities of race 2 on tomato was...
The nematicidal activity of crudely milled powders of stems, leaves, and bulbs of , , , , , , , and on eggs and J2 population densities of race 2 on tomato was examined under glasshouse conditions. These plant species have medicinal properties and are being used in South Africa by traditional healers as so-called "muti." All plant species showed a suppressive effect. Relative to untreated control, the soil amendments consistently suppressed population densities in tomato roots and the reproductive potential (RP) of the nematode. When compared to fenamiphos, a commercial systemic chemical nematicide, the soil amendments performed comparable or better in suppressing nematode populations in the root systems in 2008 and 2009, but fenamiphos performed better than all soil amendments in 2011. The RP of was comparable for both soil amendment- and fenamiphos-treated plants. No consistent trend in the effect of the soil amendments on plant root and shoot bioweight was observed, except when plants were treated with -based soil amendments and both root and shoot bioweight were consistently higher compared with untreated control plants. Our results show that the plant species examined are potential sources of phytonematicides effective against race 2. The nematicidal activity of crudely milled powders of stems, leaves, and bulbs of , , , , , , , and on eggs and J2 population densities of race 2 on tomato was examined under glasshouse conditions. These plant species have medicinal properties and are being used in South Africa by traditional healers as so-called “muti.” All plant species showed a suppressive effect. Relative to untreated control, the soil amendments consistently suppressed population densities in tomato roots and the reproductive potential (RP) of the nematode. When compared to fenamiphos, a commercial systemic chemical nematicide, the soil amendments performed comparable or better in suppressing nematode populations in the root systems in 2008 and 2009, but fenamiphos performed better than all soil amendments in 2011. The RP of was comparable for both soil amendment- and fenamiphos-treated plants. No consistent trend in the effect of the soil amendments on plant root and shoot bioweight was observed, except when plants were treated with -based soil amendments and both root and shoot bioweight were consistently higher compared with untreated control plants. Our results show that the plant species examined are potential sources of phytonematicides effective against race 2.
PubMed: 32270654
DOI: 10.21307/jofnem-2020-029