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Environmental Health Perspectives Jun 1980The phenylphosphonothioate insecticides EPN and leptophos, and several analogs, were evaluated with respect to their delayed neurotoxic effects in hens and their... (Comparative Study)
Comparative Study
The phenylphosphonothioate insecticides EPN and leptophos, and several analogs, were evaluated with respect to their delayed neurotoxic effects in hens and their environmental behavior in a terrestrial-aquatic model ecosystem. Acute toxicity to insects was highly correlated with sigma sigma of the substituted phenyl group (regression coefficient r = -0.91) while acute toxicity to mammals was slightly less well correlated (regression coefficient r = -0.71), and neurotoxicity was poorly correlated with sigma sigma (regression coefficient r = -0.35). Both EPN and leptophos were markedly more persistent and bioaccumulative in the model ecosystem than parathion. Desbromoleptophos, a contaminant and metabolite of leptophos, was seen to be a highly stable and persistent terminal residue of leptophos.
Topics: Animals; Ataxia; Chickens; Cholinesterase Inhibitors; Environmental Pollutants; Female; Houseflies; Leptophos; Organothiophosphorus Compounds; Paralysis; Pesticides; Phenylphosphonothioic Acid, 2-Ethyl 2-(4-Nitrophenyl) Ester; Structure-Activity Relationship
PubMed: 6159210
DOI: 10.1289/ehp.8036187 -
Data in Brief Apr 2022Cytochrome P450 2B6 (CYP2B6) is a human enzyme important in chemical detoxification, steroid and fatty acid metabolism that is primarily hepatic. Therefore, induction or...
Cytochrome P450 2B6 (CYP2B6) is a human enzyme important in chemical detoxification, steroid and fatty acid metabolism that is primarily hepatic. Therefore, induction or inhibition of CYP2B6 may perturb endo- and xenobiotic metabolism and cause adverse reactions. Recent research indicates that mice lacking Cyp2b enzymes are obese with liver steatosis [1] (Heintz et al., , 70:125-137, 2019). Current work is underway to determine the role of CYP2B6 in obesity and fatty acid metabolism, and CYP2B6 fluorescent inhibition assays were used to determine the IC50s of multiple industrial chemicals, pesticides, bile acids, steroids, and fatty acids. In many cases, inhibition of CYP3A4 was also performed in comparison because CYP3A4 is the most abundant hepatic detoxification CYP and therefore by abundance alone may also play a key role in the chemical's metabolism. Further, using the ratio of comparative potency of these compounds for CYP2B6 and CYP3A4, specificity can be estimated for these CYP2B6 inhibitors. These results indicate strong preferential inhibition (greater than 10-fold) of CYP2B6 and include lithocholic acid, arachidonic acid, atrazine, chlorpyrifos, endosulfan, parathion, and nonylphenol. Estradiol was a strong preferential inhibitor of CYP3A4. Other screened CYP2B6 inhibitors include triclosan, ticlopidine, jet fuel, docosahexaenoic acid, linoleic acid, linolenic acid, oleic acid, lithocholic acid, butylate, hexachlorocyclohexane, vinclozolin, pentachlorophenol, metalachlor, butylate, diazinon, avermectin, tribufos, ticlopidine, and bisphenol A. Documentation of xenobiotic and endobiotic inhibition by these CYPs is necessary for proper modeling of the effects of diet, chemical exposure or even mixtures on drug metabolism and potential adverse reactions.
PubMed: 35282180
DOI: 10.1016/j.dib.2022.108013 -
BioMed Research International 2014The toxicity of organophosphate insecticides for nontarget organism has been the subject of extensive research for sustainable agriculture. Pakistan has banned the use...
The toxicity of organophosphate insecticides for nontarget organism has been the subject of extensive research for sustainable agriculture. Pakistan has banned the use of methyl/ethyl parathions, but they are still illegally used. The present study is an attempt to estimate the residual concentration and to suggest remedial solution of adsorption by different types of soils collected and characterized for physicochemical parameters. Sorption of pesticides in soil or other porous media is an important process regulating pesticide transport and degradation. The percentage removal of methyl parathion and ethyl parathion was determined through UV-Visible spectrophotometer at 276 nm and 277 nm, respectively. The results indicate that agricultural soil as compared to barren soil is more efficient adsorbent for both insecticides, at optimum batch condition of pH 7. The equilibrium between adsorbate and adsorbent was attained in 12 hours. Methyl parathion is removed more efficiently (by seven orders of magnitude) than ethyl parathion. It may be attributed to more available binding sites and less steric hindrance of methyl parathion. Adsorption kinetics indicates that a good correlation exists between distribution coefficient (Kd) and soil organic carbon. A general increase in Kd is noted with increase in induced concentration due to the formation of bound or aged residue.
Topics: Adsorption; Agriculture; Hydrogen-Ion Concentration; Kinetics; Methyl Parathion; Models, Chemical; Parathion; Soil; Temperature; Time Factors
PubMed: 24689059
DOI: 10.1155/2014/831989 -
Movement Disorders : Official Journal... May 2022Dream-enacting behavior is a characteristic feature of rapid eye movement sleep behavior disorder, the most specific prodromal marker of synucleinopathies. Pesticide...
BACKGROUND
Dream-enacting behavior is a characteristic feature of rapid eye movement sleep behavior disorder, the most specific prodromal marker of synucleinopathies. Pesticide exposure may be associated with dream-enacting behaviors, but epidemiological evidence is limited.
OBJECTIVES
To examine high pesticide exposure events in relation to dream-enacting behaviors among farmers in the Agricultural Health Study.
METHODS
We conducted multivariable logistic regression analyses to examine high pesticide exposure events reported from 1993 to 1997 in relation to dream-enacting behaviors assessed from 2013 to 2015 among 11,248 farmers (age 47 ± 11 years).
RESULTS
A history of dream-enacting behaviors was reported by 939 (8.3%) farmers. Compared with farmers who did not report any high pesticide exposure event, those who reported were more likely to endorse dream-enacting behaviors 2 decades later (odds ratio = 1.75; 95% confidence interval [CI], 1.49-2.05). The association appeared stronger when there was a long delay in washing with soap and water after the event (2.63 [95% CI, 1.62-4.27] for waiting >6 hours vs. 1.71 [95% CI, 1.36-2.15] for washing within 30 minutes) and when the exposure involved the respiratory or digestive tract (2.04 [95% CI, 1.62-2.57] vs. 1.58 [95% CI, 1.29-1.93] for dermal contact only). In the analyses of specific pesticides involved, we found positive associations with two organochlorine insecticides (dichlorodiphenyltrichloroethane and lindane), four organophosphate insecticides (phorate, ethoprop, terbufos, and parathion), two herbicides (alachlor and paraquat), and fungicides as a group.
CONCLUSIONS
This study provides the first epidemiological evidence that high pesticide exposures may be associated with a higher risk of dream-enacting behaviors. © 2022 International Parkinson and Movement Disorder Society.
Topics: Adult; Agriculture; Farmers; Humans; Insecticides; Middle Aged; Occupational Exposure; Pesticides
PubMed: 35152487
DOI: 10.1002/mds.28960 -
Brain Research Bulletin Apr 2017Organophosphate pesticides elicit developmental neurotoxicity through mechanisms over and above their shared property as cholinesterase inhibitors. We compared the...
Organophosphate pesticides elicit developmental neurotoxicity through mechanisms over and above their shared property as cholinesterase inhibitors. We compared the consequences of neonatal exposure (postnatal days PN1-4) to diazinon or parathion on development of norepinephrine systems in rat brain, using treatments designed to produce equivalent effects on cholinesterase, straddling the threshold for barely-detectable inhibition. Norepinephrine levels were measured throughout development from the immediate posttreatment period (PN5), to early adolescence (PN30), young adulthood (PN60) and full adulthood (PN100); we assessed multiple brain regions containing all the major noradrenergic synaptic projections. Diazinon elicited a significant overall deficit of norepinephrine, whereas parathion produced a net increase. The effects were not immediately apparent (PN5) but rather emerged over the course of development, indicating that the organophosphate effects represent alteration of the trajectory of development, not just continuance of an initial injury. There were no comparable effects on β-adrenergic receptors, indicating that the presynaptic changes were not an adaptation to an underlying, primary effect on postsynaptic receptor signaling. Because we used the cholinesterase inhibition benchmark, the absolute dose of diazinon was much higher than that of parathion, since the latter is a more potent cholinesterase inhibitor. Our results are consistent with the growing evidence that the various organophosphates can differ in their impact on brain development and that consequently, the cholinesterase benchmark is an inadequate predictor of adverse neurodevelopmental effects.
Topics: Animals; Animals, Newborn; Brain; Cholinesterase Inhibitors; Diazinon; Female; Insecticides; Male; Norepinephrine; Parathion; Rats, Sprague-Dawley
PubMed: 28235599
DOI: 10.1016/j.brainresbull.2017.02.004 -
Microorganisms Jun 2023The use of pesticides in agricultural practices raises concerns considering the toxic effects they generate in the environment; thus, their sustainable application in... (Review)
Review
The use of pesticides in agricultural practices raises concerns considering the toxic effects they generate in the environment; thus, their sustainable application in crop production remains a challenge. One of the frequently addressed issues regarding their application includes the development of a sustainable and ecofriendly approach for their degradation. Since the filamentous fungi can bioremediate various xenobiotics owing to their efficient and versatile enzymatic machinery, this review has addressed their performance in the biodegradation of organochlorine and organophosphorus pesticides. It is focused particularly on fungal strains belonging to the genera and , since both are ubiquitous in the environment, and often abundant in soils contaminated with xenobiotics. Most of the recent reviews on microbial biodegradation of pesticides focus primarily on bacteria, and the soil filamentous fungi are mentioned only marginally there. Therefore, in this review, we have attempted to demonstrate and highlight the exceptional potential of aspergilli and penicillia in degrading the organochlorine and organophosphorus pesticides (e.g., endosulfan, lindane, chlorpyrifos, and methyl parathion). These biologically active xenobiotics have been degraded by fungi into various metabolites efficaciously, or these are completely mineralized within a few days. Since they have demonstrated high rates of degradation activity, as well as high tolerance to pesticides, most of the and species strains listed in this review are excellent candidates for the remediation of pesticide-contaminated soils.
PubMed: 37374987
DOI: 10.3390/microorganisms11061485 -
Toxics Jan 2023Methyl parathion (MP) has been widely used as an organophosphorus pesticide for food preservation and pest management, resulting in its accumulation in the aquatic...
Methyl parathion (MP) has been widely used as an organophosphorus pesticide for food preservation and pest management, resulting in its accumulation in the aquatic environment. However, the early developmental toxicity of MP to non-target species, especially aquatic vertebrates, has not been thoroughly investigated. In this study, zebrafish embryos were treated with 2.5, 5, or 10 mg/L of MP solution until 72 h post-fertilization (hpf). The results showed that MP exposure reduced spontaneous movement, hatching, and survival rates of zebrafish embryos and induced developmental abnormalities such as shortened body length, yolk edema, and spinal curvature. Notably, MP was found to induce cardiac abnormalities, including pericardial edema and decreased heart rate. Exposure to MP resulted in the accumulation of reactive oxygen species (ROS), decreased superoxide dismutase (SOD) activity, increased catalase (CAT) activity, elevated malondialdehyde (MDA) levels, and caused cardiac apoptosis in zebrafish embryos. Moreover, MP affected the transcription of cardiac development-related genes (, , , , , ) and apoptosis-related genes (, , ). Astaxanthin could rescue MP-induced heart development defects by down-regulating oxidative stress. These findings suggest that MP induces cardiac developmental toxicity and provides additional evidence of MP toxicity to aquatic organisms.
PubMed: 36668810
DOI: 10.3390/toxics11010084 -
British Journal of Clinical Pharmacology Dec 2022Organophosphorus (OP) insecticide poisoning causes respiratory failure due to acetylcholinesterase (AChE) inhibition. The AChE reactivating antidote pralidoxime was...
Organophosphorus (OP) insecticide poisoning causes respiratory failure due to acetylcholinesterase (AChE) inhibition. The AChE reactivating antidote pralidoxime was developed in the 1950s and was soon noted to benefit patients occupationally poisoned with the highly potent OP insecticide parathion. Routine use of pralidoxime and other oximes such as obidoxime then became widely recommended. However, nearly all severe cases of OP poisoning now result from self-poisoning with large volumes of less potent (WHO hazard class Ib and II) insecticides and co-formulated solvents. Unfortunately, oxime clinical trials have never shown benefit from their use for these patients, and some have shown that pralidoxime may be associated with harm, including increased mortality. Oximes should not be used routinely for the care of OP insecticide-poisoned patients until translational and clinical studies have identified a safe and effective oxime regimen and identified the patients who benefit.
Topics: Humans; Insecticides; Oximes; Acetylcholinesterase; Organophosphorus Compounds; Organophosphate Poisoning; Cholinesterase Inhibitors; Poisoning
PubMed: 34989015
DOI: 10.1111/bcp.15217 -
Journal of Pharmaceutical Analysis Aug 2022Balancing the risks and benefits of organophosphate pesticides (OPs) on human and environmental health relies partly on their accurate measurement. A highly sensitive...
Balancing the risks and benefits of organophosphate pesticides (OPs) on human and environmental health relies partly on their accurate measurement. A highly sensitive fluorescence anti-quenching multi-residue bio-barcode immunoassay was developed to detect OPs (triazophos, parathion, and chlorpyrifos) in apples, turnips, cabbages, and rice. Gold nanoparticles were functionalized with monoclonal antibodies against the tested OPs. DNA oligonucleotides were complementarily hybridized with an RNA fluorescent label for signal amplification. The detection signals were generated by DNA-RNA hybridization and ribonuclease H dissociation of the fluorophore. The resulting fluorescence signal enables multiplexed quantification of triazophos, parathion, and chlorpyrifos residues over the concentration range of 0.01-25, 0.01-50, and 0.1-50 ng/mL with limits of detection of 0.014, 0.011, and 0.126 ng/mL, respectively. The mean recovery ranged between 80.3% and 110.8% with relative standard deviations of 7.3%-17.6%, which correlate well with results obtained by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The proposed bio-barcode immunoassay is stable, reproducible and reliable, and is able to detect low residual levels of multi-residue OPs in agricultural products.
PubMed: 36105157
DOI: 10.1016/j.jpha.2022.05.004 -
Environmental Health Perspectives Jun 1999Six million children live in poverty in America's inner cities. These children are at high risk of exposure to pesticides that are used extensively in urban schools,... (Review)
Review
Six million children live in poverty in America's inner cities. These children are at high risk of exposure to pesticides that are used extensively in urban schools, homes, and day-care centers for control of roaches, rats, and other vermin. The organophosphate insecticide chlorpyrifos and certain pyrethroids are the registered pesticides most heavily applied in cities. Illegal street pesticides are also in use, including tres pasitos (a carbamate), tiza china, and methyl parathion. In New York State in 1997, the heaviest use of pesticides in all counties statewide was in the urban boroughs of Manhattan and Brooklyn. Children are highly vulnerable to pesticides. Because of their play close to the ground, their hand-to-mouth behavior, and their unique dietary patterns, children absorb more pesticides from their environment than adults. The long persistence of semivolatile pesticides such as chlorpyrifos on rugs, furniture, stuffed toys, and other absorbent surfaces within closed apartments further enhances urban children's exposures. Compounding these risks of heavy exposures are children's decreased ability to detoxify and excrete pesticides and the rapid growth, development, and differentiation of their vital organ systems. These developmental immaturities create early windows of great vulnerability. Recent experimental data suggest, for example, that chlorpyrifos may be a developmental neurotoxicant and that exposure in utero may cause biochemical and functional aberrations in fetal neurons as well as deficits in the number of neurons. Certain pyrethroids exert hormonal activity that may alter early neurologic and reproductive development. Assays currently used for assessment of the toxicity of pesticides are insensitive and cannot accurately predict effects to children exposed in utero or in early postnatal life. Protection of American children, and particularly of inner-city children, against the developmental hazards of pesticides requires a comprehensive strategy that monitors patterns of pesticide use on a continuing basis, assesses children's actual exposures to pesticides, uses state-of-the-art developmental toxicity testing, and establishes societal targets for reduction of pesticide use.
Topics: Adult; Animals; Child; Drug Evaluation, Preclinical; Endocrine Glands; Environmental Exposure; Female; History, 19th Century; History, 20th Century; Humans; Infant; Nervous System; Pesticides; Poverty; Pregnancy; Rats; Risk Factors; United States; United States Environmental Protection Agency; Urban Health
PubMed: 10346991
DOI: 10.1289/ehp.99107s3431