Genotoxicity of methyl parathion in short‐term bacterial test systems

Rashid, Kamal A.; Mumma, Ralph O.

doi:10.1080/03601238409372451

Cited by 8 publications

(4 citation statements)

References 19 publications

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“…Other studies have reported that the transformation of MP with partially purified rat brain fraction was not due to the monoxygenase‐dependent activation [7]. A previous study observed that MP induced a positive genotoxic response in S. typhimurium strain TA100 only after being metabolically activated with rat liver S9 enzymes [12]. In the present study, MP induced a genotoxic response both with and without metabolic activation (Table 1).…”

Section: Discussionsupporting

confidence: 65%

“…Chem. 19,2000 T.-H. Cho et al zymes [12]. In the present study, MP induced a genotoxic response both with and without metabolic activation ( Table 1).…”

Section: Discussionsupporting

confidence: 56%

“…Methyl parathion was reported to exhibit estrogenic activity in yeast and trout he‐patocyte aggregate cultures [10]. Additionally, MP was reported to have mutagenic potential in bacterial and mammalian cells [3,11,12]. A study demonstrated that MP was bioaccumulated in aquatic organisms, which could lead to inhibition of egg viability and hepatic glutathione depletion [13].…”

Section: Introductionmentioning

confidence: 99%

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Utility of organophosphorus hydrolase for the remediation of mutagenicity of methyl parathion

Cho

Wild

Donnelly

2000

Enviro Toxic and Chemistry

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The pesticide methyl parathion (MP) is widely distributed in the environment and is chemically similar to nerve agents used in chemical warfare. Detoxification of this class of compounds is a critical environmental concern. Toxicity of MP is primarily associated with the inhibition of cholinesterase activity and resulting effects on the nervous system. Methyl parathion can also induce a genotoxic effect in bacterial and mammalian cells. However, the major metabolite of MP degradation, p‐nitrophenol (PNP), is generally considered less toxic. This study reports on the evaluation of the genotoxic effect of MP, PNP, and a 1:1 MP:PNP mixture, and the utility of an organophosphorus hydrolase (OPH) enzyme for degradation of MP. Although MP induced a positive genotoxic response in Salmonella typhimurium TA100 at a dose of 1,000 μg per plate, PNP and a 1:1 mixture of PNP and MP did not induce a positive response. Methyl parathion dissolved in Luria‐Bertani broth containing 5% methanol was treated with genetically engineered intact Escherichia coli cells expressing OPH activity. Significant rates of MP biodegradation were observed in the liquid culture. Within 55 h, an average 95.5% of the MP was converted to PNP as measured spectrophotometrically. The genotoxic potential of extracts of OPH‐treated and untreated MP‐amended media was measured with S. typhimurium strain TA100. The untreated media induced a dose‐dependent genotoxic response at a dose equivalent to 54 ml of medium (MP 0.025 mg/ml) per plate, whereas the OPH‐treated media failed to induce a genotoxic response. Chemical analysis indicated that about 90% of MP was removed from the media by treatment with OPH enzyme. These studies indicate that the OPH enzyme is capable of degrading MP and eliminating its genotoxic potential in liquid culture.

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Section: Discussionsupporting

confidence: 65%

“…Chem. 19,2000 T.-H. Cho et al zymes [12]. In the present study, MP induced a genotoxic response both with and without metabolic activation ( Table 1).…”

Section: Discussionsupporting

confidence: 56%

Section: Introductionmentioning

confidence: 99%

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Utility of organophosphorus hydrolase for the remediation of mutagenicity of methyl parathion

Cho

Wild

Donnelly

2000

Enviro Toxic and Chemistry

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“…Negative results have been reported in mutagenic assays with MP on Salmonella and Streptomyces (Carere et al 1978), and positive results in Salm¿rneIla with and without S9 mix (Waters et al 1980, Rashid and Mumma 1984, Breau et al 1985. The compound is probably mutagenic in Escha'chia coli, inducing 5-methyltryptophan (5-MT) resistance (Mohn 1973a, b).…”

Section: Introductionmentioning

confidence: 99%

Detection of micronuclei in peripheral erythrocytes ofCyprinus carpio exposed to metallic mercury

Nepomuceno

Ferrari

Spanó

et al. 1997

Environ. Mol. Mutagen.

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Methyl parathion (MP) is a commonly used organophosphorus insecticide, commercially available as Folidol 600. This chemical substance was tested to determine micronucleus (MN) frequencies in peripheral erythrocytes of the fish Cypnnus c e i o treated in vivo. The concentrations tested were 1.25,2.50,5.00 and 7.50 ppm. Fish were killed after 24 or 48 h of treatment. There was a significant increase in the frequency of micronuclei in the animals treated with 2.50 and 5.00 ppm after 24 h. At higher dosages this effect disap peared probably due to the increased cell lethality. The frequency of MN induction was lower at 48 than at 24 h after treatment. There was a dosedependent increase in MN frequency which, however, was significant only at the highest concentration (7.50 ppm) compared to control. RESUMENEl metil paratión (MP) es un insecticida organofosforado disponible comercialmente como Folidol 600. Esta substancia fue probada para determinar la frecuencia de micronúcleos (MN) en eritrocitos periféricos de peces Cyprinus ca+o tratados in vivo. Las concentraciones utilizadas fueron 1.25,2.50, 5.00 y 7.50 ppm. Los peces fueron sacrificados 24 y 48 h después del tratamiento. Se notó un aumento significativo en la frecuencia de micronúcleos en los animales tratados con 2.50 y 5.00 ppm y sacrificados después de 24 h. A concentraciones mayores este efecto desapareció probablemente debido al incremento de la letalidad celular. La frecuencia de inducción de MN fue menor después de 48 h que a 24 h del tratamiento. En la primera hubo una elevación en la frecuencia de MN dependiente de la concentración que, sin embargo, fue significativa cuando se comparó con el testigo solamente en la mayor (7.50 ppm).

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Effect of paraoxon‐methyl and parathion‐methyl on DNA in human lymphocytes and protective action of vitamin C

Błasiak

Kowalik

1999

Pestic. Sci.

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The molecular basis of the genotoxicity of the commonly used organophosphorus insecticide, parathion-methyl is poorly understood and there is a lack of information on the possible effects of its metabolic conversion products. In the present work the action of parathion-methyl and its immediate metabolite paraoxon-methyl on DNA in human lymphocytes was compared using the comet assay. Parathion-methyl at 25 and 75 mM did not cause any signi®cant changes but at 200 mM a signi®cant increase in the tail moment was observed as compared with the control. Paraoxon-methyl at 25, 75 and 200 mM evoked dose-dependent DNA damage measured as a signi®cant increase in comet tail moment of lymphocytes. The change evoked by paraoxon-methyl at 200 mM was much more pronounced than that by parathion-methyl at the same concentration. To search for the mechanism underlying the observed effect, the action of a well-known antioxidant, vitamin C, along with parathion-methyl and paraoxon-methyl was studied. The vitamin at 10 and 50 mM reduced the DNA-damaging activity of paraoxon-methyl at all its concentrations. The results indicate that the reported genotoxic effects of parathion-methyl could be mainly attributed to its metabolite paraoxon-methyl. The protective action of vitamin C suggests that paraoxon-methyl may cause oxidative DNA damage.

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Genotoxicity of methyl parathion in short‐term bacterial test systems

Cited by 8 publications

References 19 publications

Utility of organophosphorus hydrolase for the remediation of mutagenicity of methyl parathion

Utility of organophosphorus hydrolase for the remediation of mutagenicity of methyl parathion

Detection of micronuclei in peripheral erythrocytes ofCyprinus carpio exposed to metallic mercury

Effect of paraoxon‐methyl and parathion‐methyl on DNA in human lymphocytes and protective action of vitamin C

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