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Reviews of Environmental Contamination... 1996Mevinphos (trade name, Phosdrin), a category 1 organophosphorus insecticide, has been used mainly as a cleanup pesticide for vegetable crops. A risk assessment for... (Review)
Review
Mevinphos (trade name, Phosdrin), a category 1 organophosphorus insecticide, has been used mainly as a cleanup pesticide for vegetable crops. A risk assessment for occupational and dietary exposure to mevinphos was initiated because of the high acute toxicity of the compound. Repetitive dosing with mevinphos did not cause any discernible histopathological effects in mice or rats, nor was it oncogenic in either species. The principal toxic effects of mevinphos, both short- and long term, were due to inhibition of cholinesterase activity. Consequently, potential adverse effects from short-term exposures were the primary concern. A human no-observed-effect level (0.025 mg/kg) for cholinergic signs was used as the regulatory basis for calculating margins of safety (MOSs) for potential acute dietary and short-term occupational exposures. Estimates of exposure to mixer/loaders, pilots, and flaggers associated with aerial application of mevinphos were based on passive dosimetry. Because no acceptable exposure studies for work tasks associated with ground application of mevinphos were available, surrogate data based on ground application of oxydemeton-methyl were used. Exposure estimates for field workers and harvesters relied on measured dislodgeable foliar residues of mevinphos and transfer factors generated from studies of other active ingredients. MOSs for mean acute occupational exposure of mixer/loader/applicators associated with ground application and of harvesters working in fruit trees were less than the value conventionally recommended to protect people from the toxic effects of mevinphos. MOSs for the 95th percentile of short-term worker exposure for all mixer/loader work categories associated with mevinphos application were also inadequate. Calculated MOSs for potential acute dietary exposure to measured residue levels of mevinphos were adequate for the various population subgroups. However, 25 of the USEPA tolerances for mevinphos on agricultural commodities were not adequate to protect for the toxic effects of mevinphos from theoretical acute dietary exposure to one or more population subgroups if commodities are consumed with residues at the tolerance level. When the mean short-term occupational exposures were combined with potential acute dietary exposure, the MOSs for mixer/loaders engaged in aerial applications, as well as ground applications, were inadequate to protect people from the toxic effects of mevinphos. As mitigation of the estimated excessive occupational exposures did not appear possible, both California and the USEPA were preparing to cancel registration of the product. However, an agreement was worked out between the manufacturer and the two agencies that ended production for domestic use but allowed existing stocks in the channels of trade to continue to be used for a limited period.
Topics: Animals; Diet; Dose-Response Relationship, Drug; Humans; Insecticides; Mevinphos; Occupational Exposure; Risk Assessment
PubMed: 8714219
DOI: 10.1007/978-1-4613-8478-6_1 -
Comparative Biochemistry and... Jan 2024Mevinphos, an organophosphate insecticide, is widely used to control pests and enhance crop yield. Because of its high solubility, it can easily flow into water and...
Mevinphos, an organophosphate insecticide, is widely used to control pests and enhance crop yield. Because of its high solubility, it can easily flow into water and threaten the aquatic environment, and it is known to be hazardous to non-target organisms. However, little is known about its developmental toxicity and the underlying toxic mechanisms. In this study, we utilized zebrafish, which is frequently used for toxicological research to estimate the toxicity in other aquatic organisms or vertebrates including humans, to elucidate the developmental defects induced by mevinphos. Here, we observed that mevinphos induced various phenotypical abnormalities, such as diminished eyes and head sizes, shortened body length, loss of swim bladder, and increased pericardiac edema. Also, exposure to mevinphos triggered inflammation, apoptosis, and DNA fragmentation in zebrafish larvae. In addition, MAPK and Akt signaling pathways, which control apoptosis, inflammation, and proper development of various organs, were also altered by the treatment of mevinphos. Furthermore, these factors induced various organ defects which were confirmed by various transgenic models. We identified neuronal toxicity through transgenic olig2:dsRed zebrafish, cardiovascular toxicity through transgenic fli1:eGFP zebrafish, and hepatotoxicity and pancreatic toxicity through transgenic lfabp:dsRed;elastase:GFP zebrafish. Overall, our results elucidated the developmental toxicities of mevinphos in zebrafish and provided the parameters for the assessment of toxicities in aquatic environments.
Topics: Animals; Humans; Mevinphos; Zebrafish; Proto-Oncogene Proteins c-akt; Signal Transduction; Apoptosis; Inflammation; Embryo, Nonmammalian
PubMed: 37858660
DOI: 10.1016/j.cbpc.2023.109768 -
Journal of Hazardous Materials Mar 2023Known organophosphorus pesticides are used widely in agriculture to improve the production of crops. Based on the literature, the degradation of some organophosphorus...
Known organophosphorus pesticides are used widely in agriculture to improve the production of crops. Based on the literature, the degradation of some organophosphorus pesticides was studied theoretically. However, the mechanisms and variation of toxicity during the degradation of mevinphos and monocrotophos are still unclear in the environment, especially in wastewater. In this study, the reaction mechanisms for the degradation of the two representative organophosphorus pesticides (i.e., mevinphos and monocrotophos) in presence of OH radicals in the atmosphere and water are proposed using quantum chemical methods wB97-XD/6-311 + +G(3df,2pd)//wB97-XD/6-311 + +G(d,p). Result shows that the dominant channel is OH-addition to the C atom in CC bond with energy barriers being 15.6 and 14.7 kJ/mol, in the atmosphere and water, respectively, for mevinphos. As for monocrotophos, H-abstraction from NH group via barriers of 8.2 and 10.6 kJ/mol is more feasible in both the atmosphere and water. Moreover, the subsequent reactions of the major products in the atmosphere with NO and O were also studied to evaluate the atmospheric chemistry of mevinphos and monocrotophos. Kinetically, the total rate constant is 2.68 × 10 and 3.86 × 10 cm molecule·s for mevinphos and monocrotophos in the atmosphere and 4.91 × 10 and 7.77 × 10 M s in the water at 298 K, thus the lifetime is estimated to be 36.46-364.60 s (2.53-25.31 s) in the atmosphere, and 1.41 × 10 - 1.41 × 10 s (8.92 ×10 - 8.92 ×10 s) in the advanced oxidation processes (AOPs) system. Furthermore, ecotoxic predictions for rats and three aqueous organisms imply their toxicity are reduced during degradation by using ECOSAR and T.E.S.T program based quantitative structure and activity relationship (QSAR) method.
Topics: Animals; Rats; Mevinphos; Monocrotophos; Pesticides; Organophosphorus Compounds; Kinetics; Atmosphere; Oxidation-Reduction; Water; Hydroxyl Radical
PubMed: 36493641
DOI: 10.1016/j.jhazmat.2022.130478 -
Pesticide Biochemistry and Physiology Sep 2017Diamondback moth (Plutella xylostella L.) causes enormous damage on cruciferous vegetables and can rapidly develop resistance to all kinds of insecticides. To...
Diamondback moth (Plutella xylostella L.) causes enormous damage on cruciferous vegetables and can rapidly develop resistance to all kinds of insecticides. To effectively manage the insecticide resistance of P. xylostella, an understanding of its inheritance and stability is essential. Here we investigated the phenotypic and genotypic basis of mevinphos resistance by crossing two genetically pure lines of P. xylostella, an SH wild-type strain and an SHM resistant strain carrying 892T/T, 971C/C, and 1156T/G (TCN) mutations of the acetylcholinesterase 1 gene (Pxace1). Similar median lethal concentrations and degrees of dominance in the reciprocal cross progeny, and no plateau on the log concentration-probit line of F1 backcross and self-cross progeny, suggest that the mevinphos-resistance in P. xylostella is inherited as an autosomal and incomplete dominant trait governed by more than one gene. In the absence of mevinphos exposure, the resistance ratio and Pxace1 mutation frequency declined concomitantly in the SHM strain. After 20-generation relaxation, the mevinphos resistance decreased from 52- to 6-fold and the Pxace1 mutation frequency of the TCN haplotype pair decreased from 100% to 0%. A good correlation was found between the resistance ratio and TCN frequency within the range of 12.5- to 25-fold resistance. Since there was no TCN haplotype pair detected below a resistance level of 12.5-fold, we speculate that resistance mechanisms other than target site insensitivity may exist. These observations are important for the prediction and management of mevinphos and related organophosphate resistance in field populations of P. xylostella.
Topics: Acetylcholinesterase; Animals; Insecticide Resistance; Insecticides; Mevinphos; Moths; Mutation
PubMed: 28911742
DOI: 10.1016/j.pestbp.2016.11.008 -
American Industrial Hygiene Association... Apr 1993The exposure of sprayers and plant handlers to mevinphos, a toxic organophosphate insecticide, was evaluated in eight flower-growing greenhouses. The purpose was to...
The exposure of sprayers and plant handlers to mevinphos, a toxic organophosphate insecticide, was evaluated in eight flower-growing greenhouses. The purpose was to assess an appropriate re-entry interval for mevinphos after its application in greenhouses. Inhalational and dermal exposure was measured during two days after application by measuring mevinphos in the greenhouse air and on the foliage. Workers' dermal exposure was measured with patch and handwash samples. The method of application considerably affected the levels of mevinphos in greenhouse air and on the foliage. The occupational exposure was measured with patch and handwash samples. The method of application considerably affected the levels of mevinphos in greenhouse air and on the foliage. The occupational exposure limit for mevinphos in Finland (100 micrograms/m3) was exceeded during the use of nonthermal foggers. Usually, however, the concentration of mevinphos in the breathing zone of the workers was below 10 micrograms/m3 9-12 hr after application. Mevinphos disappeared rapidly from greenhouse air and from the foliage after application, with a half-life of 9.2 hr. These data provide evidence that the main route of exposure to mevinphos is dermal, a conclusion supported by the excellent correlation between dermal exposure and the amount of mevinphos on the foliage. The calculated re-entry interval for mevinphos was approximately 4.5 hr. However, that interval is likely to be too short in practice because the risk of dermal exposure is considerable for more than 10 hr after the application of mevinphos.
Topics: Adult; Agriculture; Agrochemicals; Air Pollutants, Occupational; Female; Humans; Male; Mevinphos; Middle Aged; Occupational Exposure; Occupational Health; Time Factors
PubMed: 8480630
DOI: 10.1080/15298669391354496 -
Forensic Science Dec 1974
Topics: Adult; Brain Chemistry; Humans; Insecticides; Kidney; Liver; Male; Mevinphos; Muscles; Stomach; Suicide
PubMed: 4461453
DOI: 10.1016/0300-9432(74)90115-0 -
Neurochemistry International Oct 2020DJ-1 (also known as PARK7) is a redox-active protein that protects against oxidative stress. This study evaluated the hypothesis that DJ-1 sustains brainstem...
DJ-1 (also known as PARK7) is a redox-active protein that protects against oxidative stress. This study evaluated the hypothesis that DJ-1 sustains brainstem cardiovascular regulation via maintaining mitochondrial function in the rostral ventrolateral medulla (RVLM), a brainstem site known to maintain blood pressure and sympathetic vasomotor tone, during cardiovascular depression elicited by the organophosphate insecticide mevinphos. In Sprague-Dawley rats, intravenous administration of mevinphos (640 μg kg) resulted in progressive hypotension, accompanied by an increase (Phase I) followed by a decrease (Phase II) of an experimental index for spontaneous baroreflex-mediated sympathetic vasomotor tone, alongside elevation in mitochondrial superoxide levels in the RVLM. There was concurrent activation of DJ-1 induced by oxidative stress in the RVLM, which was causally and temporally related to translocation of DJ-1 to mitochondria, reduction in mitochondrial membrane potential, increase in cytosolic apoptosis-inducing factor level, and apoptotic cell death in this brainstem site. Loss-of-function by immunoneutralization of DJ-1 in the RVLM significantly exacerbated those biochemical and cellular events, enhanced the progressive hypotension, diminished the increased and augmented the decreased spontaneous baroreflex-mediated sympathetic vasomotor tone respectively during Phases I and II, and heightened lethality during mevinphos intoxication. We conclude that DJ-1 in the RVLM sustains brainstem cardiovascular regulation induced by mevinphos via maintaining mitochondrial function.
Topics: Animals; Brain Stem; Cardiovascular Physiological Phenomena; Cholinesterase Inhibitors; Male; Mevinphos; Microinjections; Mitochondria; Oxidation-Reduction; Protein Deglycase DJ-1; Rats; Rats, Sprague-Dawley
PubMed: 32650030
DOI: 10.1016/j.neuint.2020.104791 -
Pesticide Biochemistry and Physiology Jun 2014The diamondback moth, Plutella xylostella L., is the most destructive insect pest of Brassica crops in the world. It has developed resistance rapidly to almost every...
The diamondback moth, Plutella xylostella L., is the most destructive insect pest of Brassica crops in the world. It has developed resistance rapidly to almost every insecticide used for its control. Mevinphos, a fast degrading and slow resistance evocating organophosphorus insecticide, has been recommended for controlling P. xylostella in Taiwan for more than 40years. SHM strain of P. xylostella, with ca. 22-fold resistance to this chemical, has been established from a field SH strain by selecting with mevinphos since 1997. Three mutations, i.e., G892T, G971C, and T1156T/G leading to A298S, G324A, and F386F/V amino acid substitutions in acetylcholinesterase1 (AChE1), were identified in these two strains; along with three haplotype pairs and a polymorphic intron in AChE1 gene (ace1). Two genetically pure lines, i.e., an SHggt wild type with intron AS and an SHMTCN mutant carrying G892T, G971C, T1156T/G mutations and intron AR in ace1, were established by single pair mating and haplotype determination. The F1 of SHMTCN strain had 52-fold resistance to mevinphos in comparison with the F1 of SHggt strain. In addition, AChE1 of this SHMTCN population, which exhibited lower maximum velocity (Vmax) and affinity (Km), was less susceptible to the inhibition of mevinphos, with an I50 32-fold higher than that of the SHggt F1 population. These results imply that amino acid substitutions in AChE1 of SHMTCN strain are associated with mevinphos resistance in this insect pest, and this finding is important for insecticide resistance management of P. xylostella in the field.
Topics: Acetylcholinesterase; Amino Acid Substitution; Animals; Biocatalysis; Brassica; Female; Haplotypes; Insect Proteins; Insecticide Resistance; Insecticides; Introns; Kinetics; Male; Mevinphos; Models, Molecular; Moths; Mutation, Missense; Plant Diseases; Plant Leaves; Polymorphism, Genetic; Protein Structure, Tertiary; Species Specificity
PubMed: 24974111
DOI: 10.1016/j.pestbp.2014.04.009 -
Neuropharmacology Sep 2017Activation of PI3K/Akt signaling, leading to upregulation of nitric oxide synthase II (NOS II)/peroxynitrite cascade in the rostral ventrolateral medulla (RVLM), the...
Activation of PI3K/Akt signaling, leading to upregulation of nitric oxide synthase II (NOS II)/peroxynitrite cascade in the rostral ventrolateral medulla (RVLM), the brain stem site that maintains blood pressure and sympathetic vasomotor tone, underpins cardiovascular depression induced by the organophosphate pesticide mevinphos. By exhibiting dual-specificity protein- and lipid-phosphatase activity, phosphatase and tensin homolog (PTEN) directly antagonizes the PI3K/Akt signaling by dephosphorylation of phosphatidylinositol-3,4,5-trisphosphate, the lipid product of PI3K. Based on the guiding hypothesis that PTEN may sustain brain stem cardiovascular regulation during mevinphos intoxication as a negative regulator of PI3K/Akt signaling in the RVLM, we aimed in this study to clarify the mechanistic role of PTEN in mevinphos-induced circulatory depression. Microinjection bilaterally of mevinphos (10 nmol) into the RVLM of anesthetized Sprague-Dawley rats induced a progressive hypotension and a decrease in baroreflex-mediated sympathetic vasomotor tone. There was progressive augmentation in PTEN activity as reflected by a decrease in the oxidized form of PTEN in the RVLM during mevinhpos intoxication, without significant changes in the mRNA or protein level of PTEN. Loss-of-function manipulations of PTEN in the RVLM by immunoneutralization, pharmacological blockade or siRNA pretreatment significantly potentiated the increase in Akt activity or NOS II/peroxynitrite cascade in the RVLM, enhanced the elicited hypotension and exacerbated the already reduced baroreflex-mediated sympathetic vasomotor tone. We conclude that augmented PTEN activity via a decrease of its oxidized form in the RVLM sustains brain stem cardiovascular regulation during mevinphos intoxication via downregulation of the NOS II/peroxynitrite cascade as a negative regulator of PI3K/Akt signaling.
Topics: Animals; Baroreflex; Blood Pressure; Cardiovascular Agents; Heart Rate; Male; Medulla Oblongata; Mevinphos; Nitric Oxide Synthase Type I; Nitric Oxide Synthase Type II; Oxidation-Reduction; PTEN Phosphohydrolase; Peroxynitrous Acid; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; RNA, Messenger; Rats, Sprague-Dawley
PubMed: 28601397
DOI: 10.1016/j.neuropharm.2017.06.007 -
Biochemical Pharmacology Jan 2015FLJ10540, originally identified as a microtubule-associated protein, induces cell proliferation and migration during tumorigenesis via the formation of FLJ10540-PI3K...
FLJ10540, originally identified as a microtubule-associated protein, induces cell proliferation and migration during tumorigenesis via the formation of FLJ10540-PI3K complex and enhancement of PI3K kinase activity. Interestingly, activation of PI3K/Akt cascade, leading to upregulation of nitric oxide synthase II (NOS II)/peroxynitrite signaling in the rostral ventrolateral medulla (RVLM), the brain stem site that maintains blood pressure and sympathetic vasomotor tone, mediates the impairment of brain stem cardiovascular regulation induced by the pesticide mevinphos. We evaluated the hypothesis that upregulation of FLJ10540 in the RVLM is upstream to this repertoire of signaling cascade that underpins mevinphos-induced circulatory depression. Microinjection bilaterally of mevinphos (10nmol) into the RVLM of anesthetized Sprague-Dawley rats induced a progressive hypotension that was accompanied by an increase (Phase I), followed by a decrease (Phase II) of an experimental index for baroreflex-mediated sympathetic vasomotor tone. There was augmentation in FLJ10540 mRNA in the RVLM or FLJ10540 protein in RVLM neurons, both of which were causally and temporally related to an augmentation of binding between the catalytic subunit (p110) and regulatory subunit (p85) of PI3K, phosphorylation of Akt at Thr308 site, and NOS II, superoxide or peroxynitrite level in the RVLM. Immunoneutralization of FJL10540 in the RVLM significantly antagonized those biochemical changes, and blunted the progressive hypotension and the reduced baroreflex-mediated sympathetic vasomotor tone during mevinphos intoxication. We conclude that upregulation of FLJ10540 in the RVLM elicits impairment of brain stem cardiovascular regulation that underpins circulatory depression during mevinphos intoxication via activation of PI3K/Akt/NOS II/peroxynitrite signaling cascade in the RVLM.
Topics: Animals; Brain Stem; Cardiovascular Physiological Phenomena; Cell Cycle Proteins; Male; Medulla Oblongata; Mevinphos; Nuclear Proteins; Phosphatidylinositol 3-Kinases; Rats; Rats, Sprague-Dawley; Up-Regulation
PubMed: 25449601
DOI: 10.1016/j.bcp.2014.10.018