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Title: Vitamin K3 (menadione) redox cycling inhibits cytochrome P450-mediated metabolism and inhibits parathion intoxication

Abstract

Parathion, a widely used organophosphate insecticide, is considered a high priority chemical threat. Parathion toxicity is dependent on its metabolism by the cytochrome P450 system to paraoxon (diethyl 4-nitrophenyl phosphate), a cytotoxic metabolite. As an effective inhibitor of cholinesterases, paraoxon causes the accumulation of acetylcholine in synapses and overstimulation of nicotinic and muscarinic cholinergic receptors, leading to characteristic signs of organophosphate poisoning. Inhibition of parathion metabolism to paraoxon represents a potential approach to counter parathion toxicity. Herein, we demonstrate that menadione (methyl-1,4-naphthoquinone, vitamin K3) is a potent inhibitor of cytochrome P450-mediated metabolism of parathion. Menadione is active in redox cycling, a reaction mediated by NADPH-cytochrome P450 reductase that preferentially uses electrons from NADPH at the expense of their supply to the P450s. Using human recombinant CYP 1A2, 2B6, 3A4 and human liver microsomes, menadione was found to inhibit the formation of paraoxon from parathion. Administration of menadione bisulfite (40 mg/kg, ip) to rats also reduced parathion-induced inhibition of brain cholinesterase activity, as well as parathion-induced tremors and the progression of other signs and symptoms of parathion poisoning. These data suggest that redox cycling compounds, such as menadione, have the potential to effectively mitigate the toxicity of organophosphorus pesticides including parathionmore » which require cytochrome P450-mediated activation. - Highlights: • Menadione redox cycles with cytochrome P450 reductase and generates reactive oxygen species. • Redox cycling inhibits cytochrome P450-mediated parathion metabolism. • Short term administration of menadione inhibits parathion toxicity by inhibiting paraoxon formation.« less

Authors:
 [1];  [1];  [1];  [2];  [3];  [2];  [1]
  1. Department of Environmental and Occupational Medicine, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ (United States)
  2. Department of Pharmacology and Toxicology, Rutgers University, Piscataway, NJ (United States)
  3. Department of Environmental Health Science, New York Medical College, Valhalla, NY (United States)
Publication Date:
OSTI Identifier:
22687772
Resource Type:
Journal Article
Journal Name:
Toxicology and Applied Pharmacology
Additional Journal Information:
Journal Volume: 288; Journal Issue: 1; Other Information: Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0041-008X
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; ACETYLCHOLINE; BRAIN; CHOLINESTERASE; CYTOCHROMES; INHIBITION; LIVER; METABOLISM; METABOLITES; MICROSOMES; OXIDOREDUCTASES; PARATHION; PHOSPHATES; RATS; RECEPTORS; SYMPTOMS; TOXICITY; VITAMINS

Citation Formats

Jan, Yi-Hua, Richardson, Jason R., E-mail: jricha3@eohsi.rutgers.edu, Baker, Angela A., Mishin, Vladimir, Heck, Diane E., Laskin, Debra L., and Laskin, Jeffrey D., E-mail: jlaskin@eohsi.rutgers.edu. Vitamin K3 (menadione) redox cycling inhibits cytochrome P450-mediated metabolism and inhibits parathion intoxication. United States: N. p., 2015. Web. doi:10.1016/J.TAAP.2015.07.023.
Jan, Yi-Hua, Richardson, Jason R., E-mail: jricha3@eohsi.rutgers.edu, Baker, Angela A., Mishin, Vladimir, Heck, Diane E., Laskin, Debra L., & Laskin, Jeffrey D., E-mail: jlaskin@eohsi.rutgers.edu. Vitamin K3 (menadione) redox cycling inhibits cytochrome P450-mediated metabolism and inhibits parathion intoxication. United States. doi:10.1016/J.TAAP.2015.07.023.
Jan, Yi-Hua, Richardson, Jason R., E-mail: jricha3@eohsi.rutgers.edu, Baker, Angela A., Mishin, Vladimir, Heck, Diane E., Laskin, Debra L., and Laskin, Jeffrey D., E-mail: jlaskin@eohsi.rutgers.edu. Thu . "Vitamin K3 (menadione) redox cycling inhibits cytochrome P450-mediated metabolism and inhibits parathion intoxication". United States. doi:10.1016/J.TAAP.2015.07.023.
@article{osti_22687772,
title = {Vitamin K3 (menadione) redox cycling inhibits cytochrome P450-mediated metabolism and inhibits parathion intoxication},
author = {Jan, Yi-Hua and Richardson, Jason R., E-mail: jricha3@eohsi.rutgers.edu and Baker, Angela A. and Mishin, Vladimir and Heck, Diane E. and Laskin, Debra L. and Laskin, Jeffrey D., E-mail: jlaskin@eohsi.rutgers.edu},
abstractNote = {Parathion, a widely used organophosphate insecticide, is considered a high priority chemical threat. Parathion toxicity is dependent on its metabolism by the cytochrome P450 system to paraoxon (diethyl 4-nitrophenyl phosphate), a cytotoxic metabolite. As an effective inhibitor of cholinesterases, paraoxon causes the accumulation of acetylcholine in synapses and overstimulation of nicotinic and muscarinic cholinergic receptors, leading to characteristic signs of organophosphate poisoning. Inhibition of parathion metabolism to paraoxon represents a potential approach to counter parathion toxicity. Herein, we demonstrate that menadione (methyl-1,4-naphthoquinone, vitamin K3) is a potent inhibitor of cytochrome P450-mediated metabolism of parathion. Menadione is active in redox cycling, a reaction mediated by NADPH-cytochrome P450 reductase that preferentially uses electrons from NADPH at the expense of their supply to the P450s. Using human recombinant CYP 1A2, 2B6, 3A4 and human liver microsomes, menadione was found to inhibit the formation of paraoxon from parathion. Administration of menadione bisulfite (40 mg/kg, ip) to rats also reduced parathion-induced inhibition of brain cholinesterase activity, as well as parathion-induced tremors and the progression of other signs and symptoms of parathion poisoning. These data suggest that redox cycling compounds, such as menadione, have the potential to effectively mitigate the toxicity of organophosphorus pesticides including parathion which require cytochrome P450-mediated activation. - Highlights: • Menadione redox cycles with cytochrome P450 reductase and generates reactive oxygen species. • Redox cycling inhibits cytochrome P450-mediated parathion metabolism. • Short term administration of menadione inhibits parathion toxicity by inhibiting paraoxon formation.},
doi = {10.1016/J.TAAP.2015.07.023},
journal = {Toxicology and Applied Pharmacology},
issn = {0041-008X},
number = 1,
volume = 288,
place = {United States},
year = {2015},
month = {10}
}