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Archives of Toxicology Apr 2021Organophosphate pesticides (OPs) are known to inhibit acetylcholine esterase (AChE), a critical effect used to establish health-based guidance values. This study... (Comparative Study)
Comparative Study
Prediction of dose-dependent in vivo acetylcholinesterase inhibition by profenofos in rats and humans using physiologically based kinetic (PBK) modeling-facilitated reverse dosimetry.
Organophosphate pesticides (OPs) are known to inhibit acetylcholine esterase (AChE), a critical effect used to establish health-based guidance values. This study developed a combined in vitro-in silico approach to predict AChE inhibition by the OP profenofos in rats and humans. A physiologically based kinetic (PBK) model was developed for both species. Parameter values for profenofos conversion to 4-bromo-2-chlorophenol (BCP) were derived from in vitro incubations with liver microsomes, liver cytosol, and plasma from rats (catalytic efficiencies of 1.1, 2.8, and 0.19 ml/min/mg protein, respectively) and humans (catalytic efficiencies of 0.17, 0.79, and 0.063 ml/min/mg protein, respectively), whereas other chemical-related parameter values were derived using in silico calculations. The rat PBK model was evaluated against literature data on urinary excretion of conjugated BCP. Concentration-dependent inhibition of rat and human AChE was determined in vitro and these data were translated with the PBK models to predicted dose-dependent AChE inhibition in rats and humans in vivo. Comparing predicted dose-dependent AChE inhibition in rats to literature data on profenofos-induced AChE inhibition revealed an accurate prediction of in vivo effect levels. Comparison of rat predictions (BMDL10 of predicted dose-response data of 0.45 mg/kg bw) and human predictions (BMDL10 of predicted dose-response data of 0.01 mg/kg bw) suggests that humans are more sensitive than rats, being mainly due to differences in kinetics. Altogether, the results demonstrate that in vivo AChE inhibition upon acute exposure to profenofos was closely predicted in rats, indicating the potential of this novel approach method in chemical hazard assessment.
Topics: Acetylcholinesterase; Animals; Cholinesterase Inhibitors; Computer Simulation; Dose-Response Relationship, Drug; Female; Humans; Male; Microsomes, Liver; Models, Biological; Organothiophosphates; Pesticides; Rats; Rats, Sprague-Dawley; Species Specificity
PubMed: 33651127
DOI: 10.1007/s00204-021-03004-4 -
The Lancet. Planetary Health Jul 2020Agrochemical pollution of surface waters is a growing global environmental challenge, especially in areas where agriculture is rapidly expanding and intensifying.... (Review)
Review
BACKGROUND
Agrochemical pollution of surface waters is a growing global environmental challenge, especially in areas where agriculture is rapidly expanding and intensifying. Agrochemicals might affect schistosomiasis transmission through direct and indirect effects on Schistosoma parasites, their intermediate snail hosts, snail predators, and snail algal resources. We aimed to review and summarise the effects of these agrochemicals on schistosomiasis transmission dynamics.
METHODS
We did a systematic review of agrochemical effects on the lifecycle of Schistosoma spp and fitted dose-response models to data regarding the association between components of the lifecycle and agrochemical concentrations. We incorporated these dose-response functions and environmentally relevant concentrations of agrochemicals into a mathematical model to estimate agrochemical effects on schistosomiasis transmission. Dose-response functions were used to estimate individual agrochemical effects on estimates of the agrochemically influenced basic reproduction number, R, for Schistosoma haematobium. We incorporated time series of environmentally relevant agrochemical concentrations into the model and simulated mass drug administration control efforts in the presence of agrochemicals.
FINDINGS
We derived 120 dose-response functions describing the effects of agrochemicals on schistosome lifecycle components. The median estimate of the basic reproduction number under agrochemical-free conditions, was 1·65 (IQR 1·47-1·79). Agrochemical effects on estimates of R for S haematobium ranged from a median three-times increase (R 5·05, IQR 4·06-5·97) to transmission elimination (R 0). Simulations of transmission dynamics subject to interacting annual mass drug administration and agrochemical pollution yielded a median estimate of 64·82 disability-adjusted life-years (DALYs) lost per 100 000 people per year (IQR 62·52-67·68) attributable to atrazine use. In areas where aquatic arthropod predators of intermediate host snails suppress transmission, the insecticides chlorpyrifos (6·82 DALYs lost per 100 000 people per year, IQR 4·13-8·69) and profenofos (103·06 DALYs lost per 100 000 people per year, IQR 89·63-104·90) might also increase the disability burden through their toxic effects on arthropods.
INTERPRETATION
Expected environmental concentrations of agrochemicals alter schistosomiasis transmission through direct and indirect effects on intermediate host and parasite densities. As industrial agricultural practices expand in areas where schistosomiasis is endemic, strategies to prevent increases in transmission due to agrochemical pollution should be developed and pursued.
FUNDING
National Science Foundation, National Institutes of Health.
Topics: Agrochemicals; Animals; Environmental Pollutants; Environmental Pollution; Food Chain; Host-Parasite Interactions; Humans; Schistosoma; Schistosomiasis
PubMed: 32681899
DOI: 10.1016/S2542-5196(20)30105-4 -
Scientific Reports Oct 2022Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) an invasive mealybug on cotton is primarily controlled by conventional insecticides. An endoparasitoid...
Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) an invasive mealybug on cotton is primarily controlled by conventional insecticides. An endoparasitoid Aenasius arizonenesis (Girault) (Hymenoptera: Encyrtidae) is a potential biocontrol agent of this pest. We assessed the susceptibility in field populations of P. solenopsis and A. arizonensis to commonly used insecticides: profenofos, imidacloprid and thiodicarb. Reproductive traits of the parasitoid and Environmental Risk Assessment (ERA) parameters viz., Reduction coefficient, Descriptive analysis, Risk Index (RI), Selectivity ratio and Hazard quotient were measured to assess the direct and indirect effects of these insecticides on the parasitoid. Probit analysis revealed heterogeneity in the insecticide resistance development for both the cotton mealybug and its parasitoid. The field populations of P. solenopsis exhibited resistance to profenofos (18.87-59.86 folds) and thiodicarb (20.07 folds) and susceptibility to imidacloprid. Development of resistance to profenofos was observed in field populations of A. arizonensis. Exposure to lethal doses of imidacloprid and profenofos caused a reduction in parasitization (19-23%) and adult emergence (62-69%) of the parasitoid. Profenofos, thiodicarb and imidacloprid were found to be hazardous, non-selective and harmful to the endoparasitoid, A. arizonensis. There is an urgent need for optimizing insecticide applications for sustainable management of this invasive mealybug in cotton.
Topics: Animals; Gossypium; Hemiptera; Hymenoptera; Insecticide Resistance; Insecticides; Neonicotinoids; Nitro Compounds; Organothiophosphates; Thiocarbamates
PubMed: 36202878
DOI: 10.1038/s41598-022-20779-3 -
RSC Advances Apr 2022A colloidal silver nanoparticle (AgNP)-based lateral flow immunoassay (LFIA) was evaluated in terms of the rapid detection of profenofos (PEO) pesticide residue in...
A colloidal silver nanoparticle (AgNP)-based lateral flow immunoassay (LFIA) was evaluated in terms of the rapid detection of profenofos (PEO) pesticide residue in vegetables. Colloidal AgNPs, of a diameter of approximately 20 nm, were surface-modified with trisodium citrate dehydrate (TSC) in order to improve their stability and dispersion. An anti-profenofos polyclonal antibody (pAb) was successfully immobilized on the surface of the AgNPs by ionic interaction and characterized using UV-vis, SEM, TEM, FTIR and XPS analyses. Surface modification of Ag-pAb conjugates of varying pH, pAb content and cross-reactivity was employed to design and prepare labels for use in an LFIA to examine whether these factors affect the performance of the assay. The visible detection limit and optical detection limit of the PEO test strip were 0.20 and 0.01 ppm, respectively, in PEO standard solution. This assay showed no cross-reaction with omethoate, methamidophos or pyraclofos. Finally, the PEO test strip was effectively applied for the detection of PEO in liquid vegetables A and B, with optical detection limits of 0.09 and 0.075 ppm, respectively.
PubMed: 35497005
DOI: 10.1039/d2ra01654k -
Ecotoxicology and Environmental Safety Jul 2023As an environmental pollutant, profenofos (PFF) can seriously endanger human health through the food chain. Albicanol is a sesquiterpene compound with antioxidant,...
As an environmental pollutant, profenofos (PFF) can seriously endanger human health through the food chain. Albicanol is a sesquiterpene compound with antioxidant, anti-inflammatory, and anti-aging properties. Previous studies have shown that Albicanol can antagonize apoptosis and genotoxicity caused by PFF exposure. However, the toxicity mechanism of PFF regulating hepatocyte immune function, apoptosis, and programmed necrosis and the role of Albicanol in this process have not been reported yet. In this study, grass carp hepatocytes (L8824) were treated with PFF (200 μM) or combined with Albicanol (5 ×10 μg mL) for 24 h to establish an experimental model. The results of JC-1 probe staining and Fluo-3 AM probe staining showed increased free calcium ions and decreased mitochondrial membrane potential in L8824 cells after PFF exposure, suggesting that PFF exposure may lead to mitochondrial damage. Real-time quantitative PCR and Western blot results showed that PFF exposure could increase the transcription of innate immunity-related factors (C3, Pardaxin 1, Hepcidin, INF-γ, IL-8, and IL-1β) in L8824 cells. PFF up-regulated the TNF/NF-κB signaling pathway and the expression of caspase-3, caspase-9, Bax, MLKL, RIPK1, and RIPK3 and down-regulated the expression of Caspase-8 and Bcl-2. Albicanol can antagonize the above-mentioned effects caused by PFF exposure. In conclusion, Albicanol antagonized the mitochondrial damage, apoptosis, and necroptosis of grass carp hepatocytes caused by PFF exposure by inhibiting the TNF/NF-κB pathway in innate immunity.
Topics: Humans; Animals; NF-kappa B; Immunity, Innate; Apoptosis; Sesquiterpenes; Carps
PubMed: 37196524
DOI: 10.1016/j.ecoenv.2023.115014 -
Toxicology International Jan 2014In this study we have evaluated the genotoxic potential of pesticides acephate and profenofos by polymerase chain reaction-restriction fragment length polymorphism...
OBJECTIVES
In this study we have evaluated the genotoxic potential of pesticides acephate and profenofos by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay with the mosquito Culex quinquefasciatus taken as experimental model.
MATERIAL AND METHODS
Second instar larvae were treated with LC20 of each pesticide for 24 h and induced mutations in the sequence of mitochondrial 16S rRNA gene were studied from restriction patterns generated with PacI and PsiI restriction endonucleases.
RESULTS
Variations in the number and size of digested fragments were recorded from treated individuals compared with controls showing that the restriction enzymes created a cut at different locations. In addition, sequences of the 16S gene from control and treated individuals were also used to confirm the RFLP patterns. From the sequence alignment data, it was found that mutations caused the destruction and generation of restriction sites in the gene sequence of treated individuals.
CONCLUSION
This study indicates that both the pesticides had significant potential to induce mutations in the 16S gene of Culex quinquefasciatus.
PubMed: 24748740
DOI: 10.4103/0971-6580.128809 -
Ecotoxicology and Environmental Safety Dec 2021The organophosphorus (OP) and carbamate (CB) insecticides are responsible for inhibition of the Acetylcholinesterase (AChE) enzyme. The AChE activity, therefore, has...
The organophosphorus (OP) and carbamate (CB) insecticides are responsible for inhibition of the Acetylcholinesterase (AChE) enzyme. The AChE activity, therefore, has been demonstrated to be a potent biomarker for these insecticides in terrestrial and aquatic environments. The objective of this study was to investigate the response of AChE in the brain of four-week old fingerlings of silver perch, Bidyanus bidyanus exposed to OP and CB insecticides. The fish fingeling were exposed to three OPs and one CB insecticide as individual and their binary mixtures for 48 h. The OP insecticides with oxon (PO) as well as thion (PS) group gets oxidized to oxon analogs in biological systems. The 50% AChE inhibition (48 h EC) in fingerling exposed to chlorpyrifos (CPF) and triazophos (TRZ) was evident at 2.3 and 6.7 µg/L, respectively. The toxicological interaction of three OPs and one CB insecticide was evaluated using the toxic unit method. A strong synergism was observed for binary combination of CPF with profenofos (PRF), and CPF with TAZ. In contrast, the mixture of TAZ with PRF and carbofuran (CBF) with CPF and PRF showed antagonistic behavior. Although OP and CB insecticides can break down rapidly in the environment, this study suggests that non-target aquatic biota may be exposed to mixtures of ChE-inhibiting insecticides for a period of several months, in agricultural regions where insecticides are applied for extended periods of the year. And at environmentally relevant concentrations such mixtures may lead to deleterious effects in non-target organisms.
Topics: Acetylcholinesterase; Animals; Chlorpyrifos; Cholinesterase Inhibitors; Insecticides; Perches
PubMed: 34653840
DOI: 10.1016/j.ecoenv.2021.112790 -
Chemosphere May 2018Organophosphorus (OP) compounds can bind covalently to many types of proteins and form protein adducts. These protein adducts can indicate the exposure to and...
Organophosphorus (OP) compounds can bind covalently to many types of proteins and form protein adducts. These protein adducts can indicate the exposure to and neurotoxicity of OPs. In the present work, we studied adduction of tubulin with the OP insecticide profenofos in vitro and optimized the method for detection of adducted peptides. Porcine tubulin was incubated with profenofos and was then digested with trypsin, followed by mass spectrometric identification of the profenofos-modified tubulin and binding sites. With solvent-assisted digestion (80% acetonitrile in digestion solution), the protein was digested for peptide identification, especially for some peptides with low mass. The MALDI-TOF-MS and LC-ESI-TOF-MS analysis results showed that profenofos bound covalently to Tyr83 in porcine α-tubulin (TGTY*R) and to Tyr281 in porcine β-tubulin (GSQQY*R) with a mass increase of 166.02 Da from the original peptide fragments of porcine tubulin proteins. Tyrosine adduct sites were also confirmed by MALDI-TOF/TOF-MS analysis. This result may partially explain the neurotoxicity of profenofos at low doses and prolonged periods of exposure.
Topics: Animals; Binding Sites; Chromatography, Liquid; Insecticides; Organophosphorus Compounds; Organothiophosphates; Protein Binding; Proteins; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Swine; Tubulin; Tyrosine
PubMed: 29433029
DOI: 10.1016/j.chemosphere.2018.02.003 -
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 -
Environmental Analysis, Health and... Dec 2022The aim of the study was to assess the occurrence and distribution of organophosphate compounds residue in soil, surface water, sediment, and banana crops in Araromi...
The aim of the study was to assess the occurrence and distribution of organophosphate compounds residue in soil, surface water, sediment, and banana crops in Araromi farm settlement, Osun State, Nigeria. Organophosphate pesticide residues were determined using a gas chromatography equipped with Flame-Ionization Detection (GC-FID) in 16 soil samples from cocoa and banana farms, 6 water and sediment samples each, and 8 banana samples from 4 farms in the study site. Fourteen organophosphate compounds were detected (acephate, omethoate, dementon-s-methyl, dimethoate, tolcofos-methyl, pirimiphos-methyl, malathion, chlorpyrifos, methidathion, prothiofos, profenofos, ethion, azinphos-methyl and pyrazophos). Tolclofos-methyl, pirimiphos-methyl and prothiofos were detected in all the soil and sediment samples with concentration ranges of 1.9-12.9, 2.25-6.98 and 3.38-9.89 mg/kg respectively in soil and 8.13-9.83, 2.82-25.1 and 3.70-19.5 mg/kg respectively in sediment. Dimethoate, pirimiphos-methyl and prothiofos with concentration ranges, 0.06-0.28, 0.09-0.18 and 0.16-6.11 mg/L respectively were mostly detected in water samples while dimethoate, tolcofos-methyl, malathion, methidathion, prothiofos, ethion and azinphos-methyl compounds were detected in all the banana samples with concentration ranges, 3.40-12.0, 1.82-6.26, 5.73-9.48, 29.7-145, 8.24-20.1, 3.87-9.35 and 3.66-12.2 mg/kg respectively. The organophosphate mean residue concentrations were mostly significantly higher than the Maximum Residue Limits (MRL) at p<0.05. Across the three samples, only pirimiphos-methyl was significantly higher in water samples, omethoate in sediment; acephate, dementon-s-methyl and chlorpyrifos in banana were also not significantly higher at p<0.05. A strong positive significant correlation was observed between the organophosphate compounds in the banana and water samples (R=0.77, p=0.002) at p<0.05. The occurrence of organophosphate compounds in concentrations above MRLs may pose serious environmental and health risks.
PubMed: 36916048
DOI: 10.5620/eaht.2022035