1
|
Vignaux PA, Shriwas P, Revnew A, Agarwal G, Lane TR, McElroy CA, Ekins S. Human CYP2C19 Substrate and Inhibitor Characterization of Organophosphate Pesticides. Chem Res Toxicol 2023; 36:1451-1455. [PMID: 37650603 DOI: 10.1021/acs.chemrestox.3c00188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
CYP2C19 is an important enzyme for organophosphate pesticide (OPP) metabolism. Because the OPPs can be both substrates and inhibitors of CYP2C19, we screened 45 OPPs for their ability to inhibit the activity of this enzyme and investigated the role of CYP2C19 in the metabolism of 22 of these molecules. We identified several nanomolar inhibitors of CYP2C19 as well as determined that thions, in general, are more potent inhibitors than oxons. We also determined that thions are readily metabolized by CYP2C19, although we saw no relationship between IC50 values and intrinsic clearance rates. This study may have implications for mitigating the risk of OPP poisoning.
Collapse
Affiliation(s)
- Patricia A Vignaux
- Collaborations Pharmaceuticals, Inc., Raleigh, North Carolina 27606, United States
| | - Pratik Shriwas
- Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, Ohio 43210, United States
| | - Andre Revnew
- Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, Ohio 43210, United States
| | - Garima Agarwal
- Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, Ohio 43210, United States
| | - Thomas R Lane
- Collaborations Pharmaceuticals, Inc., Raleigh, North Carolina 27606, United States
| | - Craig A McElroy
- Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, Ohio 43210, United States
| | - Sean Ekins
- Collaborations Pharmaceuticals, Inc., Raleigh, North Carolina 27606, United States
| |
Collapse
|
2
|
Zhang Z, Meng M, Wu Q, Kim JH, Zhu Y. Biodegradation and metabolic pathway of quinalphos by Cunninghamella elegans ATCC36112. Biotechnol Lett 2023:10.1007/s10529-023-03393-9. [PMID: 37195489 DOI: 10.1007/s10529-023-03393-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 04/27/2023] [Accepted: 04/30/2023] [Indexed: 05/18/2023]
Abstract
Quinalphos is a long-term, wide-spectrum organophosphate insecticide with residual problems in the natural environment. Cunninghamella elegans (C. elegans) is a member of Mucoromycotina. Since the degradation products of its exogenous compounds are similar to those of mammals, it is often used to simulate the metabolism pathways of mammals. In this study, the detailed metabolic pathways of quinalphos were investigated with C. elegans. Quinalphos was degraded by 92% in 7 days, while ten metabolites were produced. The metabolites were analyzed and identified by GC-MS. To determine the responsible enzymes in quinalphos metabolism, piperonyl butoxide (PB) and methimazole included in the culture flasks, and the kinetic responses of quinalphos and its metabolites by C. elegans were measured. Results indirectly demonstrated that cytochrome P450 monooxygenases were involved in the metabolism of quinalphos, but that methimazole inhibited the metabolism less efficiently. Comprehensive metabolic pathways can be deduced from the detailed analysis of metabolite profiles in control and inhibitor assays.
Collapse
Affiliation(s)
- Zhenxing Zhang
- College of Plant Health and Medicine, Qingdao Agricultural University, Changcheng Road, Chengyang, Qingdao, 266-109, Shandong, China
| | - Min Meng
- College of Plant Health and Medicine, Qingdao Agricultural University, Changcheng Road, Chengyang, Qingdao, 266-109, Shandong, China
| | - Qiong Wu
- College of Chemistry and Pharmacy, Qingdao Agricultural University, Changcheng Road, Chengyang, Qingdao, 266-109, Shandong, China
| | - Jeong-Han Kim
- Department of Agricultural Biotechnology, Seoul National University, 599 Gwanak-ro, Silim-dong, Gwanak-Gu, Seoul, 151-742, Republic of Korea
| | - Yongzhe Zhu
- College of Chemistry and Pharmacy, Qingdao Agricultural University, Changcheng Road, Chengyang, Qingdao, 266-109, Shandong, China.
| |
Collapse
|
3
|
Agarwal G, Tichenor H, Roo S, Lane TR, Ekins S, McElroy CA. Targeted Metabolomics of Organophosphate Pesticides and Chemical Warfare Nerve Agent Simulants Using High- and Low-Dose Exposure in Human Liver Microsomes. Metabolites 2023; 13:metabo13040495. [PMID: 37110155 PMCID: PMC10144572 DOI: 10.3390/metabo13040495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Revised: 03/21/2023] [Accepted: 03/23/2023] [Indexed: 03/31/2023] Open
Abstract
Our current understanding of organophosphorus agent (pesticides and chemical warfare nerve agents) metabolism in humans is limited to the general transformation by cytochrome P450 enzymes and, to some extent, by esterases and paraoxonases. The role of compound concentrations on the rate of clearance is not well established and is further explored in the current study. We discuss the metabolism of 56 diverse organophosphorus compounds (both pesticides and chemical warfare nerve agent simulants), many of which were explored at two variable dose regimens (high and low), determining their clearance rates (Clint) in human liver microsomes. For compounds that were soluble at high concentrations, 1D-NMR, 31P, and MRM LC-MS/MS were used to calculate the Clint and the identity of certain metabolites. The determined Clint rates ranged from 0.001 to 2245.52 µL/min/mg of protein in the lower dose regimen and from 0.002 to 98.57 µL/min/mg of protein in the high dose regimen. Though direct equivalency between the two regimens was absent, we observed (1) both mono- and bi-phasic metabolism of the OPs and simulants in the microsomes. Compounds such as aspon and formothion exhibited biphasic decay at both high and low doses, suggesting either the involvement of multiple enzymes with different KM or substrate/metabolite effects on the metabolism. (2) A second observation was that while some compounds, such as dibrom and merphos, demonstrated a biphasic decay curve at the lower concentrations, they exhibited only monophasic metabolism at the higher concentration, likely indicative of saturation of some metabolic enzymes. (3) Isomeric differences in metabolism (between Z- and E- isomers) were also observed. (4) Lastly, structural comparisons using examples of the oxon group over the original phosphorothioate OP are also discussed, along with the identification of some metabolites. This study provides initial data for the development of in silico metabolism models for OPs with broad applications.
Collapse
Affiliation(s)
- Garima Agarwal
- Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA
| | - Hunter Tichenor
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Sarah Roo
- Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA
| | - Thomas R. Lane
- Collaborations Pharmaceutical Inc., Raleigh, NC 27606, USA
| | - Sean Ekins
- Collaborations Pharmaceutical Inc., Raleigh, NC 27606, USA
| | - Craig A. McElroy
- Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA
- Correspondence:
| |
Collapse
|
4
|
Miranda CA, Beretta EM, Ferreira LA, da Silva ES, Coimbra BZ, Pereira PT, Miranda RG, Dorta DJ, Rodrigues FTV, Mingatto FE. Role of biotransformation in the diazinon-induced toxicity in HepG2 cells and antioxidant protection by tetrahydrocurcumin. Toxicol Rep 2022; 10:32-39. [PMID: 36578673 PMCID: PMC9791245 DOI: 10.1016/j.toxrep.2022.12.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 11/27/2022] [Accepted: 12/11/2022] [Indexed: 12/14/2022] Open
Abstract
Diazinon (DZN) is an insecticide extensively used to control pests in crops and animals. However, its indicriminated use may lead to liver damage in animals and humans. This study aimed to evaluate the toxicity of DZN (25-150 µM) on human hepatoblastoma (HepG2) cells after 24 and 48 h of exposure and the role of its biotransformation on the toxicological potential. We also tested the protective effect of tetrahydrocurcumin (THC), an antioxidant agent, in the DZN-induced citotoxicity. DZN caused cytotoxicity in the HepG2 cells, inhibiting cell proliferation and reducing cell viability in a dose- and time-dependent manner. The pre-incubation of HepG2 cells with chemical inducers of cytochrome P450 monooxygenase 3-methylcholanthrene and phenobarbital resulted in a further decrease of cell viability associated with DZN exposure. In addition, the metabolite diazoxon was more toxic than DZN. Our results also revealed that THC alleviated DZN-induced cytotoxicity and reactive oxygen and nitrogen species (RONS) generation in HepG2 cells. In conclusion, our data provide novel insights into the involvement of biotransformation in the mechanisms of DZN-induced cytotoxicity and suggest that amelioration of RONS accumulation might be involved in the protective effect of THC on DZN-induced liver injury.
Collapse
Affiliation(s)
- Camila Araújo Miranda
- Department of Animal Science, College of Agricultural and Technological Sciences, São Paulo State University (Unesp), Dracena, SP, Brazil
| | - Eduardo Morais Beretta
- Department of Animal Science, College of Agricultural and Technological Sciences, São Paulo State University (Unesp), Dracena, SP, Brazil
- Medical School, Unifadra, Faculdades de Dracena, Dracena, SP, Brazil
| | - Layra Araújo Ferreira
- Department of Animal Science, College of Agricultural and Technological Sciences, São Paulo State University (Unesp), Dracena, SP, Brazil
| | | | | | | | - Raul Ghiraldelli Miranda
- Department of Chemistry, Faculty of Philosophy, Sciences and Letters of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Daniel Junqueira Dorta
- Department of Chemistry, Faculty of Philosophy, Sciences and Letters of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Flávia Thomaz Verechia Rodrigues
- Department of Animal Science, College of Agricultural and Technological Sciences, São Paulo State University (Unesp), Dracena, SP, Brazil
| | - Fábio Erminio Mingatto
- Department of Animal Science, College of Agricultural and Technological Sciences, São Paulo State University (Unesp), Dracena, SP, Brazil
- Correspondence to: Department of Animal Science, College of Agricultural and Technological Sciences, São Paulo State University (Unesp), Dracena, 17900–000, SP, Brazil.
| |
Collapse
|
5
|
Girón-Pérez MI, Mary VS, Rubinstein HR, Toledo-Ibarra GA, Theumer MG. Diazinon toxicity in hepatic and spleen mononuclear cells is associated to early induction of oxidative stress. INTERNATIONAL JOURNAL OF ENVIRONMENTAL HEALTH RESEARCH 2022; 32:2309-2323. [PMID: 34404283 DOI: 10.1080/09603123.2021.1962814] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 07/27/2021] [Indexed: 06/13/2023]
Abstract
Diazinon is an organophosphorus pesticide, which may have potential toxic effects on the liver and immune system; however, the underlying mechanisms remain mostly unidentified. This work is aimed at evaluating the oxidative stress and cell cycle alterations elicited by low-dose diazinon in a rat liver cell line (BRL-3A) and spleen mononuclear cells (SMC) from Wistar rats. Diazinon (10-50 μM) caused early reactive oxygen species (ROS) generation (from 4 h) as well as increased O2•- level (from 0.5 h), which led to subsequent lipid peroxidation at 24 h, in BRL-3A cells. In SMC, diazinon (20 μM) produced similar increases in ROS levels, at 4 and 24 h, with the highest O2•- level being found at 4 h. Low-dose diazinon induced G1-phase arrest and cell death in hepatic cells and SMC. Therefore, diazinon could affect the liver and the immunological system through the premature oxidative stress induction.Abbreviations: O2•-: superoxide anion radical; ROS: reactive oxygen species; SMC: spleen mononuclear cells; TBARS: thiobarbituric acid reactive substances.
Collapse
Affiliation(s)
- Manuel Iván Girón-Pérez
- Universidad Autónoma de Nayarit,Secretaría de Investigación Y Posgrado, Laboratorio de Inmunotoxicología, Boulevard Tepic-Xalisco S/n, Cd de La Cultura Amado Nervo, C.P, Tepic, Nayarit, Mexico
| | - Verónica S Mary
- Departamento De Bioquímica Clínica, Facultad De Ciencias Químicas, Universidad Nacional De Córdoba (UNC), Córdoba, Argentina
- Consejo Nacional de Investigaciones Científicas Y Técnicas (CONICET), Centro de Investigaciones En Bioquímica Clínica E Inmunología (CIBICI), Córdoba, Argentina
| | - Héctor R Rubinstein
- Departamento De Bioquímica Clínica, Facultad De Ciencias Químicas, Universidad Nacional De Córdoba (UNC), Córdoba, Argentina
- Consejo Nacional de Investigaciones Científicas Y Técnicas (CONICET), Centro de Investigaciones En Bioquímica Clínica E Inmunología (CIBICI), Córdoba, Argentina
| | - Gladys A Toledo-Ibarra
- Universidad Autónoma de Nayarit,Secretaría de Investigación Y Posgrado, Laboratorio de Inmunotoxicología, Boulevard Tepic-Xalisco S/n, Cd de La Cultura Amado Nervo, C.P, Tepic, Nayarit, Mexico
| | - Martín G Theumer
- Departamento De Bioquímica Clínica, Facultad De Ciencias Químicas, Universidad Nacional De Córdoba (UNC), Córdoba, Argentina
- Consejo Nacional de Investigaciones Científicas Y Técnicas (CONICET), Centro de Investigaciones En Bioquímica Clínica E Inmunología (CIBICI), Córdoba, Argentina
| |
Collapse
|
6
|
Owumi SE, Najophe ES, Otunla MT. 3-Indolepropionic acid prevented chlorpyrifos-induced hepatorenal toxicities in rats by improving anti-inflammatory, antioxidant, and pro-apoptotic responses and abating DNA damage. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:74377-74393. [PMID: 35644820 DOI: 10.1007/s11356-022-21075-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 05/20/2022] [Indexed: 05/10/2023]
Abstract
The application of chlorpyrifos (CPF), an organophosphorus pesticide to control insects, is associated with oxidative stress and reduced quality of life in humans and animals. Indole-3-propionic acid (IPA) is a by-product of tryptophan metabolism with high antioxidant capacity and has the potential to curb CPF-mediated toxicities in the hepatorenal system of rats. It is against this background that we explored the subacute exposure of CPF and the effect of IPA in the liver and kidney of thirty rats using five cohort experimental designs (n = 6) consisting of control (corn oil 2 mL/kg body weight), CPF alone (5 mg/kg), IPA alone (50 mg/kg), CPF + IPA1 (5 mg/kg + 25 mg/kg), and CPF + IPA2 (5 mg/kg + 50 mg/kg). Subsequently, we evaluated biomarkers of hepatorenal damage, oxidative and nitrosative stress, inflammation, DNA damage, and apoptosis by spectrophotometric and enzyme-linked immunosorbent assay methods. Our results showed that co-treatment with IPA decreased CPF-upregulated serum hepatic transaminases, creatinine, and urea; reversed CPF downregulation of SOD, CAT, GPx, GST, GSH, Trx, TRx-R, and TSH; and abated CPF upregulation of XO, MPO, RONS, and LPO. Co-treatment with IPA decreased CPF-upregulated IL-1β and 8-OHdG levels, caspase-9 and caspase-3 activities, and increased IL-10. In addition, IPA averts CPF-induced histological changes in the liver and kidney of rats. Our results demonstrate that co-dosing CPF-exposed rats with IPA can significantly decrease CPF-induced oxidative stress, pro-inflammatory responses, DNA damage, and subsequent pro-apoptotic responses in rats' liver and kidneys. Therefore, supplementing tryptophan-derived endogenous IPA from exogenous sources may help avert toxicity occasioned by inadvertent exposure to harmful chemicals, including CPF-induced systemic perturbation of liver and kidney function.
Collapse
Affiliation(s)
- Solomon E Owumi
- Cancer Research and Molecular Biology Laboratories, Department of Biochemistry, Faculty of Basic Medical Sciences, University of Ibadan, Room NB 302, Ibadan, 200005, Nigeria.
| | - Eseroghene S Najophe
- Nutrition and Industrial Biochemistry Research Laboratories, Department of Biochemistry, Faculty of Basic Medical Sciences, University of Ibadan, Ibadan, 200005, Nigeria
| | - Moses T Otunla
- Cancer Research and Molecular Biology Laboratories, Department of Biochemistry, Faculty of Basic Medical Sciences, University of Ibadan, Room NB 302, Ibadan, 200005, Nigeria
| |
Collapse
|
7
|
Biosca-Brull J, Guardia-Escote L, Blanco J, Basaure P, Cabré M, Sánchez-Santed F, Domingo JL, Colomina MT. Prenatal, but not postnatal exposure to chlorpyrifos affects social behavior of mice and the excitatory-inhibitory balance in a sex-dependent manner. Food Chem Toxicol 2022; 169:113423. [PMID: 36113784 DOI: 10.1016/j.fct.2022.113423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 08/26/2022] [Indexed: 11/17/2022]
Abstract
The balance between excitatory and inhibitory neurotransmitters is essential for proper brain development. An imbalance between these two systems has been associated with neurodevelopmental disorders. On the other hand, literature also associates the massive use of pesticides with the increase of these disorders, with a particular focus on chlorpyrifos (CPF) a world-wide used organophosphate pesticide. This study was aimed at assessing social autistic-like behaviors on mice pre or postnatally exposed to CPF (0 or 1 mg/kg/day), in both sexes. In prenatal exposure, C57BL/6J pregnant mice were exposed to CPF through the diet, between gestational days (GD) 12 and 18, while a positive control group for some autistic behaviors was exposed to valproic acid (VPA) on GD 12 and 13. To assess postnatal exposure, C57BL/6J mice were orally exposed to the vehicle (corn oil) or CPF, from postnatal days (PND) 10-15. Social behavior and gene expression analysis were assessed on PND 45. Results showed social alterations only in males prenatally treated. GABA system was upregulated in CPF-treated females, whereas an increase in both systems was observed in both treated males. These findings suggest that males are more sensitive to prenatal CPF exposure, favoring the sex bias observed in ASD.
Collapse
Affiliation(s)
- Judit Biosca-Brull
- Universitat Rovira i Virgili, Research Group in Neurobehavior and Health (NEUROLAB), Tarragona, Spain; Universitat Rovira i Virgili, Department of Psychology and Research Center for Behavior Assessment (CRAMC), Tarragona, Spain; Universitat Rovira i Virgili, Laboratory of Toxicology and Environmental Health (TECNATOX), Reus, Spain.
| | - Laia Guardia-Escote
- Universitat Rovira i Virgili, Research Group in Neurobehavior and Health (NEUROLAB), Tarragona, Spain; Universitat Rovira i Virgili, Department of Psychology and Research Center for Behavior Assessment (CRAMC), Tarragona, Spain
| | - Jordi Blanco
- Universitat Rovira i Virgili, Research Group in Neurobehavior and Health (NEUROLAB), Tarragona, Spain; Universitat Rovira i Virgili, Laboratory of Toxicology and Environmental Health (TECNATOX), Reus, Spain; Universitat Rovira i Virgili, Department of Basic Medical Sciences, Reus, Spain
| | - Pia Basaure
- Universitat Rovira i Virgili, Research Group in Neurobehavior and Health (NEUROLAB), Tarragona, Spain
| | - Maria Cabré
- Universitat Rovira i Virgili, Research Group in Neurobehavior and Health (NEUROLAB), Tarragona, Spain; Universitat Rovira i Virgili, Department of Biochemistry and Biotechnology, Tarragona, Spain
| | - Fernando Sánchez-Santed
- Department of Psychology, Health Research Center (CEINSA), Almeria University, 04120, Almeria, Spain
| | - José L Domingo
- Universitat Rovira i Virgili, Laboratory of Toxicology and Environmental Health (TECNATOX), Reus, Spain
| | - Maria Teresa Colomina
- Universitat Rovira i Virgili, Research Group in Neurobehavior and Health (NEUROLAB), Tarragona, Spain; Universitat Rovira i Virgili, Department of Psychology and Research Center for Behavior Assessment (CRAMC), Tarragona, Spain; Universitat Rovira i Virgili, Laboratory of Toxicology and Environmental Health (TECNATOX), Reus, Spain.
| |
Collapse
|
8
|
Rajendran K, Dey R, Ghosh A, Das D. In search of biocatalytic remedy for organotin compounds- the recalcitrant eco-toxicants. Biophys Chem 2022; 290:106888. [DOI: 10.1016/j.bpc.2022.106888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 08/08/2022] [Accepted: 08/29/2022] [Indexed: 11/25/2022]
|
9
|
Jiang F, Wu W, Zhu Z, Zhu S, Wang H, Zhang L, Fan Z, Chen Y. Structure identification and toxicity evaluation of one newly-discovered dechlorinated photoproducts of chlorpyrifos. CHEMOSPHERE 2022; 301:134822. [PMID: 35523292 DOI: 10.1016/j.chemosphere.2022.134822] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 04/26/2022] [Accepted: 04/29/2022] [Indexed: 06/14/2023]
Abstract
Chlorpyrifos (CPF) is an extensively used organophosphorus pesticide. Recently, it has attracted increasing attention due to environmental health problems caused by it. Although numerous studies have discovered the dechlorinated photoproduct of CPF, its structure and toxicity remain largely unknown. In this study, we systematically investigated the structure and toxicity of dechlorinated photoproduct of CPF. The CPF degradation experiment was performed, and its products were identified by ultra high performance liquid chromatography-orbitrap fusion tribid mass spectrometer (UHPLC-Orbitrap Fusion TMS). Additionally, bond dissociation energy (BDE) calculations and photoproduct chemical synthesis were employed to determine the structure of dechlorinated photoproduct of CPF. The toxicity of CPF photoproduct was evaluated through the Ecological Structure Activity Relationships (ECOSAR) Class Program, the Toxicity Estimation Software Tool (T.E.S.T.) software, and acute toxicity testing. The results indicated that the dechlorinated photoproduct of CPF was identified as O,O-Diethyl-O-(3,5-dichloro-2-pyridyl) phosphorothioate (Dechloro-CPF), which was produced in large quantity within the first 30 min of photodegradation experiment. The acute and chronic toxicity values of Dechloro-CPF were obviously higher than those for the other two photoproducts. The median lethal dose (LD50) of Dechloro-CPF was 31.6 mg/kg for female mice and 58.4 mg/kg for male mice. This study reveals the photodegradation mechanism of CPF and confirms that Dechloro-CPF was dechlorinated photoproduct of CPF with potential acute toxicity to aquatic species and mammalian (including human). Our findings will contribute to a more comprehensive risk evaluation of CPF in food and the environment.
Collapse
Affiliation(s)
- Feng Jiang
- Hubei Provincial Institute for Food Supervision and Test, Wuhan, 430075, China; Key Laboratory of Detection Technology of Focus Chemical Hazards in Animal-derived Food for State Market Regulation, Wuhan, 430075, China; Hubei Provincial Engineering and Technology Research Center for Food Quality and Safety Test, Wuhan, 430075, China.
| | - Wanqin Wu
- Hubei Provincial Institute for Food Supervision and Test, Wuhan, 430075, China; Key Laboratory of Detection Technology of Focus Chemical Hazards in Animal-derived Food for State Market Regulation, Wuhan, 430075, China; Hubei Provincial Engineering and Technology Research Center for Food Quality and Safety Test, Wuhan, 430075, China
| | - Zhengwei Zhu
- Hubei Provincial Institute for Food Supervision and Test, Wuhan, 430075, China; Key Laboratory of Detection Technology of Focus Chemical Hazards in Animal-derived Food for State Market Regulation, Wuhan, 430075, China; Hubei Provincial Engineering and Technology Research Center for Food Quality and Safety Test, Wuhan, 430075, China
| | - Songsong Zhu
- Hubei Provincial Institute for Food Supervision and Test, Wuhan, 430075, China; Key Laboratory of Detection Technology of Focus Chemical Hazards in Animal-derived Food for State Market Regulation, Wuhan, 430075, China; Hubei Provincial Engineering and Technology Research Center for Food Quality and Safety Test, Wuhan, 430075, China
| | - Huixia Wang
- Hubei Provincial Institute for Food Supervision and Test, Wuhan, 430075, China; Key Laboratory of Detection Technology of Focus Chemical Hazards in Animal-derived Food for State Market Regulation, Wuhan, 430075, China; Hubei Provincial Engineering and Technology Research Center for Food Quality and Safety Test, Wuhan, 430075, China
| | - Li Zhang
- Hubei Provincial Institute for Food Supervision and Test, Wuhan, 430075, China; Key Laboratory of Detection Technology of Focus Chemical Hazards in Animal-derived Food for State Market Regulation, Wuhan, 430075, China; Hubei Provincial Engineering and Technology Research Center for Food Quality and Safety Test, Wuhan, 430075, China
| | - Zhiyong Fan
- Hubei Provincial Institute for Food Supervision and Test, Wuhan, 430075, China; Key Laboratory of Detection Technology of Focus Chemical Hazards in Animal-derived Food for State Market Regulation, Wuhan, 430075, China; Hubei Provincial Engineering and Technology Research Center for Food Quality and Safety Test, Wuhan, 430075, China
| | - Yiping Chen
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| |
Collapse
|
10
|
Nematollahi A, Rezaei F, Afsharian Z, Mollakhalili-Meybodi N. Diazinon reduction in food products: a comprehensive review of conventional and emerging processing methods. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:40342-40357. [PMID: 35322357 DOI: 10.1007/s11356-022-19294-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 02/14/2022] [Indexed: 06/14/2023]
Abstract
Diazinon is known as one of the most commonly used organophosphorus pesticides which influence different pests through inactivating acetyl choline esterase enzymes. Despite diazinon applications, its toxicity to human health could result in a worldwide concern about its occurrence in foodstuffs. Malfunction of brain is considered as the main disorders induced by long time exposure to diazinon. Due to the degradation of diazinon in high temperatures and its susceptibility to oxidation as well as acidic and basic conditions, it could be degraded through several physical (9-94%) and chemical (19.3-100%) food processing procedures (both household and industrial methods). However, each of these methods has its advantages and disadvantages. Normally, the combination of these methods is more efficient in diazinon reduction. To this end, it is important to apply an effective method for diazinon reduction in the food products without affecting food quality or treating human health. It could be noticed that bioremediation by microorganisms such as probiotics could be a promising new method for diazinon's reduction in several food products.
Collapse
Affiliation(s)
- Amene Nematollahi
- Department of Food Safety and Hygiene, School of Health, Fasa University of Medical Sciences, Fasa, Iran.
| | - Farahnaz Rezaei
- Department of Food Safety and Hygiene, School of Health, Fasa University of Medical Sciences, Fasa, Iran
| | - Zahra Afsharian
- Department of Food Science and Technology, Faculty of Nutrition Science, Food Science and Technology/National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Neda Mollakhalili-Meybodi
- Department of Food Sciences and Technology, School of Public Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
- Research Center for Food Hygiene and Safety, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
| |
Collapse
|
11
|
Ooka M, Zhao J, Shah P, Travers J, Klumpp-Thomas C, Xu X, Huang R, Ferguson S, Witt KL, Smith-Roe SL, Simeonov A, Xia M. Identification of environmental chemicals that activate p53 signaling after in vitro metabolic activation. Arch Toxicol 2022; 96:1975-1987. [PMID: 35435491 PMCID: PMC9151520 DOI: 10.1007/s00204-022-03291-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Accepted: 03/24/2022] [Indexed: 12/11/2022]
Abstract
Currently, approximately 80,000 chemicals are used in commerce. Most have little-to-no toxicity information. The U.S. Toxicology in the 21st Century (Tox21) program has conducted a battery of in vitro assays using a quantitative high-throughput screening (qHTS) platform to gain toxicity information on environmental chemicals. Due to technical challenges, standard methods for providing xenobiotic metabolism could not be applied to qHTS assays. To address this limitation, we screened the Tox21 10,000-compound (10K) library, with concentrations ranging from 2.8 nM to 92 µM, using a p53 beta-lactamase reporter gene assay (p53-bla) alone or with rat liver microsomes (RLM) or human liver microsomes (HLM) supplemented with NADPH, to identify compounds that induce p53 signaling after biotransformation. Two hundred and seventy-eight compounds were identified as active under any of these three conditions. Of these 278 compounds, 73 gave more potent responses in the p53-bla assay with RLM, and 2 were more potent in the p53-bla assay with HLM compared with the responses they generated in the p53-bla assay without microsomes. To confirm the role of metabolism in the differential responses, we re-tested these 75 compounds in the absence of NADPH or with heat-attenuated microsomes. Forty-four compounds treated with RLM, but none with HLM, became less potent under these conditions, confirming the role of RLM in metabolic activation. Further evidence of biotransformation was obtained by measuring the half-life of the parent compounds in the presence of microsomes. Together, the data support the use of RLM in qHTS for identifying chemicals requiring biotransformation to induce biological responses.
Collapse
Affiliation(s)
- Masato Ooka
- National Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Rockville, MD, 20850, USA
| | - Jinghua Zhao
- National Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Rockville, MD, 20850, USA
| | - Pranav Shah
- National Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Rockville, MD, 20850, USA
| | - Jameson Travers
- National Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Rockville, MD, 20850, USA
| | - Carleen Klumpp-Thomas
- National Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Rockville, MD, 20850, USA
| | - Xin Xu
- National Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Rockville, MD, 20850, USA
| | - Ruili Huang
- National Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Rockville, MD, 20850, USA
| | - Stephen Ferguson
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA
| | - Kristine L Witt
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA
| | - Stephanie L Smith-Roe
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA
| | - Anton Simeonov
- National Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Rockville, MD, 20850, USA
| | - Menghang Xia
- National Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Rockville, MD, 20850, USA.
| |
Collapse
|
12
|
Zhao S, Wesseling S, Rietjens IMCM, Strikwold M. Inter-individual variation in chlorpyrifos toxicokinetics characterized by physiologically based kinetic (PBK) and Monte Carlo simulation comparing human liver microsome and Supersome ™ cytochromes P450 (CYP)-specific kinetic data as model input. Arch Toxicol 2022; 96:1387-1409. [PMID: 35294598 PMCID: PMC9013686 DOI: 10.1007/s00204-022-03251-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 02/14/2022] [Indexed: 11/25/2022]
Abstract
The present study compares two approaches to evaluate the effects of inter-individual differences in the biotransformation of chlorpyrifos (CPF) on the sensitivity towards in vivo red blood cell (RBC) acetylcholinesterase (AChE) inhibition and to calculate a chemical-specific adjustment factor (CSAF) to account for inter-individual differences in kinetics (HKAF). These approaches included use of a Supersome™ cytochromes P450 (CYP)-based and a human liver microsome (HLM)-based physiologically based kinetic (PBK) model, both combined with Monte Carlo simulations. The results revealed that bioactivation of CPF exhibits biphasic kinetics caused by distinct differences in the Km of CYPs involved, which was elucidated by Supersome™ CYP rather than by HLM. Use of Supersome™ CYP-derived kinetic data was influenced by the accuracy of the intersystem extrapolation factors (ISEFs) required to scale CYP isoform activity of Supersome™ to HLMs. The predicted dose–response curves for average, 99th percentile and 1st percentile sensitive individuals were found to be similar in the two approaches when biphasic kinetics was included in the HLM-based approach, resulting in similar benchmark dose lower confidence limits for 10% inhibition (BMDL10) and HKAF values. The variation in metabolism-related kinetic parameters resulted in HKAF values at the 99th percentile that were slightly higher than the default uncertainty factor of 3.16. While HKAF values up to 6.9 were obtained when including also the variability in other influential PBK model parameters. It is concluded that the Supersome™ CYP-based approach appeared most adequate for identifying inter-individual variation in biotransformation of CPF and its resulting RBC AChE inhibition.
Collapse
Affiliation(s)
- Shensheng Zhao
- Division of Toxicology, Wageningen University and Research, Stippeneng 4, 6708 WE, Wageningen, The Netherlands.
| | - Sebastiaan Wesseling
- Division of Toxicology, Wageningen University and Research, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | - Ivonne M C M Rietjens
- Division of Toxicology, Wageningen University and Research, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | - Marije Strikwold
- Van Hall Larenstein University of Applied Sciences, 8901 BV, Leeuwarden, The Netherlands
| |
Collapse
|
13
|
Concentration-dependent effects of chlorpyrifos oxon on peroxisome proliferator-activated receptor signaling in MCF-7 cells. Toxicol In Vitro 2022; 78:105268. [PMID: 34756920 PMCID: PMC8710288 DOI: 10.1016/j.tiv.2021.105268] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 09/21/2021] [Accepted: 10/25/2021] [Indexed: 02/03/2023]
Abstract
Chlorpyrifos oxon (CPO) is the active metabolite of the organophosphorus pesticide, chlorpyrifos. CPO is a potent inhibitor of acetylcholinesterase (AChE) and other serine hydrolases including fatty acid amide hydrolase (FAAH). AChE is critical in regulating cholinergic signaling while FAAH catalyzes the inactivation of fatty acid signaling lipids including the endocannabinoid (eCB) N-arachidonylethanolamine (anandamide, AEA) and eCB-like metabolites (e.g., oleoylethanolamide, OEA). AEA and OEA are both peroxisome proliferator-activated receptor (PPAR) agonists that regulate numerous genes involved in lipid metabolism and energy homeostasis. We used the MCF-7 human breast cancer cell line, which expresses AChE, FAAH and PPAR alpha and gamma subtypes, to evaluate the potential effects of CPO on PPAR-related gene expression in an in vitro human cell system. CPO elicited relatively similar concentration-dependent inhibition of both AChE and FAAH. Marked concentration- and time-dependent changes in the expression of four selected PPAR-related genes, LXRα, ACOX1, ABCG2 and AGPAT2, were noted. These findings suggest chlorpyrifos may influence lipid metabolism through blocking the degradation of eCBs or eCB-like metabolites and in turn affecting PPAR receptor activation. The results highlight the potential for non-cholinesterase actions of this common insecticide metabolite through disruption of PPAR signaling including effects on lipid metabolism, immune function and inflammation.
Collapse
|
14
|
Spataro F, Patrolecco L, Ademollo N, Præbel K, Rauseo J, Pescatore T, Corsolini S. Multiple exposure of the Boreogadus saida from bessel fjord (NE Greenland) to legacy and emerging pollutants. CHEMOSPHERE 2021; 279:130477. [PMID: 33857648 DOI: 10.1016/j.chemosphere.2021.130477] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 03/30/2021] [Accepted: 04/01/2021] [Indexed: 06/12/2023]
Abstract
This work investigates the occurrence of OCPs, such as hexachlorocyclohexane (α-, β-, γ- and δ-HCH) isomers, dichlorodiphenyltrichloroethane (p,p'-DDT) and its metabolite dichlorodiphenyldichloroethylene (p,p'-DDE), endosulfan (α- and β-EDS) isomers, chlorpyrifos (CPF), dacthal (DAC) and phenolic compounds, such as 4-nonylphenol (4-NP) and its precursors nonylphenol polyethoxylates (NP1EO and NP2EO) and bisphenol A (BPA), in polar cod sampled in and outside Bessel Fjord (NE Greenland). Linear regressions between target contaminants and morphological parameters (age, length, weight, gonad- and hepato-somatic indices and Fulton K) have been also evaluated. Polar cod collected at shelf had higher average concentrations of BPA, NP1EO, NP2EO and 4-NP (muscle: 6.2, 13.2, 8.9 and 1.9 ng/g w.w., respectively; liver: 5.8, 7.5, 5.2 and 0.9 ng/g w.w. respectively), than fjord's specimens (muscle: 3.5, 9.1, 3.9 and 1.0 ng/g w.w., respectively; liver: 2.4, 5.3, 2.9 and 1.1 ng/g w.w. respectively). ΣHCHs, ΣEDSs, ΣDDTs, CPF and DAC, were more accumulated in the polar cod from the fjord (average amount in muscle: 9.1, 4.8, 7.9, 3.8 and 2.8 ng/g w.w., respectively; average amount in the liver: 11.2, 9.0, 3.8, 5.9 and 4.9 ng/g w.w., respectively) than shelf's ones (average amount in muscle 3.9, 4.5, 4.2, 0.9 and 1.2 ng/g w.w., respectively; average amount in liver 7.8, 6.3, 2.1, 3.4 and 2.5 ng/g w.w., respectively). The comparison between the concentration of target contaminants and morphologic parameters suggested a different exposure of polar cod occupying the fjord and shelf habitats, due to a combination of genetic and dietary differences, climate change effects and increased human activities.
Collapse
Affiliation(s)
- F Spataro
- Institute of Polar Sciences-National Research Council (ISP-CNR), Strada Provinciale 35d, Km 0,700, 00010, Montelibretti, Rome, Italy
| | - L Patrolecco
- Institute of Polar Sciences-National Research Council (ISP-CNR), Strada Provinciale 35d, Km 0,700, 00010, Montelibretti, Rome, Italy
| | - N Ademollo
- Institute of Polar Sciences-National Research Council (ISP-CNR), Strada Provinciale 35d, Km 0,700, 00010, Montelibretti, Rome, Italy.
| | - K Præbel
- Norwegian College of Fishery Science, UiT the Arctic University of Norway, 9037, Tromsø, Norway; Department of Forestry and Wildlife Management, Campus Evenstad, Inland Norway University of Applied Science, 2418, Elverum, Norway
| | - J Rauseo
- Institute of Polar Sciences-National Research Council (ISP-CNR), Strada Provinciale 35d, Km 0,700, 00010, Montelibretti, Rome, Italy
| | - T Pescatore
- Water Research Institute- National Research Council (IRSA-CNR), Strada Provinciale 35d, Km 0,700, 00010, Montelibretti, Rome, Italy; Department of Ecological and Biological Science, Tuscia University, 01100, Viterbo, Italy
| | - S Corsolini
- Institute of Polar Sciences-National Research Council (ISP-CNR), Strada Provinciale 35d, Km 0,700, 00010, Montelibretti, Rome, Italy; Department of Physical, Earth and Environmental Sciences, Via P.A. Mattioli 4, 53100, Siena, Italy
| |
Collapse
|
15
|
Non- β-Lactam Allosteric Inhibitors Target Methicillin-Resistant Staphylococcus aureus: An In Silico Drug Discovery Study. Antibiotics (Basel) 2021; 10:antibiotics10080934. [PMID: 34438984 PMCID: PMC8388891 DOI: 10.3390/antibiotics10080934] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 07/18/2021] [Accepted: 07/29/2021] [Indexed: 11/17/2022] Open
Abstract
Penicillin-binding proteins (PBPs) catalyze the final stages for peptidoglycan cell-wall bio-synthesis. Mutations in the PBP2a subunit can attenuate β-lactam antibiotic activity, resulting in unimpeded cell-wall formation and methicillin-resistant Staphylococcus aureus (MRSA). A double mutation in PBP2a (i.e., N146K and E150K) is resistant to β-lactam inhibitors; however, (E)-3-(2-(4-cyanostyryl)-4-oxoquinazolin-3(4H)-yl) benzoic acid (QNZ), a heterocyclic antibiotic devoid of a β-lactam ring, interacts non-covalently with PBP2a allosteric site and inhibits PBP enzymatic activity. In the search for novel inhibitors that target this PBP2a allosteric site in acidic medium, an in silico screening was performed. Chemical databases including eMolecules, ChEMBL, and ChEBI were virtually screened for candidate inhibitors with a physicochemical similarity to QNZ. PBP2a binding affinities from the screening were calculated based on molecular docking with co-crystallized ligand QNZ serving as a reference. Molecular minimization calculations were performed for inhibitors with docking scores lower than QNZ (calc. −8.3 kcal/mol) followed by combined MD simulations and MM-GBSA binding energy calculations. Compounds eMol26313223 and eMol26314565 exhibited promising inhibitor activities based on binding affinities (ΔGbinding) that were twice that of QNZ (−38.5, −34.5, and −15.4 kcal/mol, respectively). Structural and energetic analyses over a 50 ns MD simulation revealed high stability for the inhibitors when complexed with the double mutated PBP2a. The pharmacokinetic properties of the two inhibitors were predicted using an in silico ADMET analysis. Calculated binding affinities hold promise for eMol26313223 and eMol26314565 as allosteric inhibitors of PBP2a in acidic medium and establish that further in vitro and in vivo inhibition experimentation is warranted.
Collapse
|
16
|
Zhao S, Wesseling S, Spenkelink B, Rietjens IMCM. Physiologically based kinetic modelling based prediction of in vivo rat and human acetylcholinesterase (AChE) inhibition upon exposure to diazinon. Arch Toxicol 2021; 95:1573-1593. [PMID: 33715020 PMCID: PMC8113213 DOI: 10.1007/s00204-021-03015-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 02/25/2021] [Indexed: 01/30/2023]
Abstract
The present study predicts in vivo human and rat red blood cell (RBC) acetylcholinesterase (AChE) inhibition upon diazinon (DZN) exposure using physiological based kinetic (PBK) modelling-facilitated reverse dosimetry. Due to the fact that both DZN and its oxon metabolite diazoxon (DZO) can inhibit AChE, a toxic equivalency factor (TEF) was included in the PBK model to combine the effect of DZN and DZO when predicting in vivo AChE inhibition. The PBK models were defined based on kinetic constants derived from in vitro incubations with liver fractions or plasma of rat and human, and were used to translate in vitro concentration-response curves for AChE inhibition obtained in the current study to predicted in vivo dose-response curves. The predicted dose-response curves for rat matched available in vivo data on AChE inhibition, and the benchmark dose lower confidence limits for 10% inhibition (BMDL10 values) were in line with the reported BMDL10 values. Humans were predicted to be 6-fold more sensitive than rats in terms of AChE inhibition, mainly because of inter-species differences in toxicokinetics. It is concluded that the TEF-coded DZN PBK model combined with quantitative in vitro to in vivo extrapolation (QIVIVE) provides an adequate approach to predict RBC AChE inhibition upon acute oral DZN exposure, and can provide an alternative testing strategy for derivation of a point of departure (POD) in risk assessment.
Collapse
Affiliation(s)
- Shensheng Zhao
- Division of Toxicology, Wageningen University and Research, Stippeneng 4, 6708 WE, Wageningen, The Netherlands.
| | - Sebastiaan Wesseling
- Division of Toxicology, Wageningen University and Research, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | - Bert Spenkelink
- Division of Toxicology, Wageningen University and Research, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | - Ivonne M C M Rietjens
- Division of Toxicology, Wageningen University and Research, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| |
Collapse
|
17
|
Tu M, Zheng X, Liu P, Wang S, Yan Z, Sun Q, Liu X. Typical organic pollutant-protein interactions studies through spectroscopy, molecular docking and crystallography: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 763:142959. [PMID: 33121791 DOI: 10.1016/j.scitotenv.2020.142959] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 09/29/2020] [Accepted: 10/08/2020] [Indexed: 06/11/2023]
Abstract
With the development of industry and human society, more attention was paid for the toxic effects of organic pollutants that are closely related to human daily life. Previous studies mainly focused on the dose-response relationship and cytotoxic effects of pollutants to organisms,while little research focused on pollutant-protein interactions at molecular level. However, the binding of organic pollutants to biomolecules, especially proteins like transporters, membrane receptor and nuclear receptors, is often the first step of toxic effects. It can make a series of endocrine disrupting and genotoxic effects through cell signaling pathway by binding specific target proteins including serum albumin, thyroid transporter, estrogen receptor, androgen receptor, and aryl hydrocarbon receptor. Thus, the research of interactions between organic pollutants and proteins is helpful and necessary to understand the distribution, metabolism and toxicity mechanism of compounds in organisms at the molecular level. This paper reviewed the latest research progress of the interaction types of persistent organic pollutants (POPs), emerging pollutants and some other pollutants with targeted proteins. In addition, we summarized several main experimental techniques for studying pollutant-protein interactions including ultraviolet/visible absorption spectrometry (UV-vis), fluorescence, infrared spectrometry, circular dichroic spectra (CD), molecular docking and X-ray crystallography. This review contributes to the molecular mechanism of the interaction between organic pollutants and biomolecules.
Collapse
Affiliation(s)
- Mengchen Tu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Xin Zheng
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Peiyuan Liu
- School of Life Sciences, Tianjin University, Tianjin, 300072, China
| | - Shuping Wang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Zhenguang Yan
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
| | - Qianhang Sun
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; College of Fisheries, Henan Normal University, Xinxiang 453007, China
| | - Xinyu Liu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| |
Collapse
|
18
|
Human Family 1-4 cytochrome P450 enzymes involved in the metabolic activation of xenobiotic and physiological chemicals: an update. Arch Toxicol 2021; 95:395-472. [PMID: 33459808 DOI: 10.1007/s00204-020-02971-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 12/29/2020] [Indexed: 12/17/2022]
Abstract
This is an overview of the metabolic activation of drugs, natural products, physiological compounds, and general chemicals by the catalytic activity of cytochrome P450 enzymes belonging to Families 1-4. The data were collected from > 5152 references. The total number of data entries of reactions catalyzed by P450s Families 1-4 was 7696 of which 1121 (~ 15%) were defined as bioactivation reactions of different degrees. The data were divided into groups of General Chemicals, Drugs, Natural Products, and Physiological Compounds, presented in tabular form. The metabolism and bioactivation of selected examples of each group are discussed. In most of the cases, the metabolites are directly toxic chemicals reacting with cell macromolecules, but in some cases the metabolites formed are not direct toxicants but participate as substrates in succeeding metabolic reactions (e.g., conjugation reactions), the products of which are final toxicants. We identified a high level of activation for three groups of compounds (General Chemicals, Drugs, and Natural Products) yielding activated metabolites and the generally low participation of Physiological Compounds in bioactivation reactions. In the group of General Chemicals, P450 enzymes 1A1, 1A2, and 1B1 dominate in the formation of activated metabolites. Drugs are mostly activated by the enzyme P450 3A4, and Natural Products by P450s 1A2, 2E1, and 3A4. Physiological Compounds showed no clearly dominant enzyme, but the highest numbers of activations are attributed to P450 1A, 1B1, and 3A enzymes. The results thus show, perhaps not surprisingly, that Physiological Compounds are infrequent substrates in bioactivation reactions catalyzed by P450 enzyme Families 1-4, with the exception of estrogens and arachidonic acid. The results thus provide information on the enzymes that activate specific groups of chemicals to toxic metabolites.
Collapse
|
19
|
Alexpandi R, De Mesquita JF, Pandian SK, Ravi AV. Quinolines-Based SARS-CoV-2 3CLpro and RdRp Inhibitors and Spike-RBD-ACE2 Inhibitor for Drug-Repurposing Against COVID-19: An in silico Analysis. Front Microbiol 2020; 11:1796. [PMID: 32793181 PMCID: PMC7390959 DOI: 10.3389/fmicb.2020.01796] [Citation(s) in RCA: 90] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 07/09/2020] [Indexed: 01/20/2023] Open
Abstract
The novel coronavirus SARS-CoV-2 disease “COVID-19” emerged in China and rapidly spread to other countries; due to its rapid worldwide spread, the WHO has declared this as a global emergency. As there is no specific treatment prescribed to treat COVID-19, the seeking of suitable therapeutics among existing drugs seems valuable. The structure availability of coronavirus macromolecules has encouraged the finding of conceivable anti-SARS-CoV-2 therapeutics through in silico analysis. The results reveal that quinoline,1,2,3,4-tetrahydro-1-[(2-phenylcyclopropyl)sulfonyl]-trans-(8CI) and saquinavir strongly interact with the active site (Cys-His catalytic dyad), thereby are predicted to hinder the activity of SARS-CoV-2 3CLpro. Out of 113 quinoline-drugs, elvitegravir and oxolinic acid are able to interact with the NTP entry-channel and thus interfere with the RNA-directed 5′-3′ polymerase activity of SARS-CoV-2 RdRp. The bioactivity-prediction results also validate the outcome of the docking study. Moreover, as SARS-CoV-2 Spike-glycoprotein uses human ACE2-receptor for viral entry, targeting the Spike-RBD-ACE2 has been viewed as a promising strategy to control the infection. The result shows rilapladib is the only quinoline that can interrupt the Spike-RBD-ACE2 complex. In conclusion, owing to their ability to target functional macromolecules of SARS-CoV-2, along with positive ADMET properties, quinoline,1,2,3,4-tetrahydro-1-[(2-phenylcyclopropyl)sulfonyl]-trans-(8CI), saquinavir, elvitegravir, oxolinic acid, and rilapladib are suggested for the treatment of COVID-19.
Collapse
Affiliation(s)
- Rajaiah Alexpandi
- Department of Biotechnology, School of Biological Sciences, Science Campus, Alagappa University, Karaikudi, India
| | - Joelma Freire De Mesquita
- Laboratory of Bioinformatics and Computational Biology, Department of Genetics and Molecular Biology, Federal University of Rio de Janeiro State (UNIRIO), Rio de Janeiro, Brazil
| | - Shunmugiah Karutha Pandian
- Department of Biotechnology, School of Biological Sciences, Science Campus, Alagappa University, Karaikudi, India
| | - Arumugam Veera Ravi
- Department of Biotechnology, School of Biological Sciences, Science Campus, Alagappa University, Karaikudi, India
| |
Collapse
|
20
|
Zhao MA, Gu H, Zhang CJ, Jeong IH, Kim JH, Zhu YZ. Metabolism of insecticide diazinon by Cunninghamella elegans ATCC36112. RSC Adv 2020; 10:19659-19668. [PMID: 35515422 PMCID: PMC9054078 DOI: 10.1039/d0ra02253e] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 04/23/2020] [Indexed: 02/04/2023] Open
Abstract
The fungal metabolism of diazinon was investigated and the microbial model (Cunninghamella elegans ATCC36112) could effectively degrade the organophosphorus pesticide (diazinon) mediated by cytochrome P450, which was mainly involved in oxidation and hydrolysis of phase I metabolism. Approximately 89% of diazinon was removed within 7 days and was not observed after 13 days with concomitant accumulation of eight metabolites. Structures of the metabolites were fully or tentatively identified with GC-MS and 1H, 13C NMR. The major metabolites of diazinon were diethyl (2-isopropyl-6-methylpyrimidin-4-yl) phosphate (diazoxon) and 2-isopropyl-6-methyl-4-pyrimidinol (pyrimidinol), and formation of minor metabolites was primarily the result of hydroxylation. To determine the responsible enzymes in diazinon metabolism, piperonyl butoxide and methimazole were treated, and the kinetic responses of diazinon and its metabolites by Cunninghamella elegans were measured. Results indirectly demonstrated that cytochrome P450 and flavin monooxygenase were involved in the metabolism of diazinon, but methimazole inhibited the metabolism less effectively. Based on the metabolic profiling, a possible metabolic pathway involved in phase I metabolism of diazinon was proposed, which would contribute to providing insight into understanding the toxicological effects of diazinon and the potential application of fungi on organophosphorus pesticides.
Collapse
Affiliation(s)
- Mei-Ai Zhao
- College of Life Sciences, Qingdao Agricultural University Changcheng Rd, Chengyang Qingdao City Shandong Province 266-109 China
| | - Hao Gu
- College of Chemistry and Pharmacy, Qingdao Agricultural University Changcheng Rd, Chengyang Qingdao City Shandong Province 266-109 China +86-532-8803-0220 +86-133-5532-5000
| | - Chuan-Jie Zhang
- College of Animal Science and Technology, Yangzhou University Yangzhou Jiangsu Province 225-009 China
| | - In-Hong Jeong
- Division of Crop Protection, National Institute of Agricultural Science, Rural Development Administration Jeollabuk-do 55365 Republic of Korea
| | - Jeong-Han Kim
- Department of Agricultural Biotechnology, Seoul National University 599 Gwanak-ro, Silim-dong, Gwanak-Gu Seoul 151-742 Republic of Korea
| | - Yong-Zhe Zhu
- College of Chemistry and Pharmacy, Qingdao Agricultural University Changcheng Rd, Chengyang Qingdao City Shandong Province 266-109 China +86-532-8803-0220 +86-133-5532-5000
| |
Collapse
|
21
|
Jeon J, Hollender J. In vitro biotransformation of pharmaceuticals and pesticides by trout liver S9 in the presence and absence of carbamazepine. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 183:109513. [PMID: 31421535 DOI: 10.1016/j.ecoenv.2019.109513] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 07/29/2019] [Accepted: 07/31/2019] [Indexed: 06/10/2023]
Abstract
The aim of the present study was to develop (i) a technique for identifying metabolites of organic contaminants by using an in vitro system of trout S9 and liquid chromatography-high-resolution mass spectrometry-based identification method and (ii) to apply this technique to identify the interactive potential of carbamazepine on the formation rate of other metabolites. The pharmaceuticals carbamazepine and propranolol and the pesticides azoxystrobin, diazinon, and fipronil were selected as test contaminants. As a result, a total of ten metabolites were identified for the five parent substances, six of which were confirmed using reference standards. Metabolic reactions included hydroxylation, epoxidation, S-oxidation, and dealkylation. The metabolic transformation rate ranged from 0.2 to 3.5 pmol/mg protein/min/μmol substrate. In the binary exposure experiment with increasing carbamazepine concentration, the formation rates of diazinon and fipronil metabolites (MDI2 and MFP2, respectively) increased, while formation of metabolites of propranolol and azoxystrobin (MPR1, MPR2, MPR3, and MAZ1) slowed down. Meanwhile, S9 pre-exposed to carbamazepine produced diazoxon, a toxic metabolite of diazinon, and pyrimidinol, a less toxic metabolite, more rapidly. These results suggest that carbamazepine, a perennial environmental pollutant, might modulate the toxicity of other substances such as diazinon but further in vivo studies are needed.
Collapse
Affiliation(s)
- Junho Jeon
- Graduate School of FEED of Eco-Friendly Offshore Structure, Changwon National University, Changwon, Gyeongsangnamdo, 51140, South Korea; School of Civil, Environmental and Chemical Engineering, Changwon National University, Changwon, Gyeongsangnamdo, 51140, South Korea; Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600, Dübendorf, Switzerland.
| | - Juliane Hollender
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600, Dübendorf, Switzerland; Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich, CH-8092, Zürich, Switzerland
| |
Collapse
|
22
|
Li S, Zhao J, Huang R, Santillo MF, Houck KA, Xia M. Use of high-throughput enzyme-based assay with xenobiotic metabolic capability to evaluate the inhibition of acetylcholinesterase activity by organophosphorous pesticides. Toxicol In Vitro 2019; 56:93-100. [PMID: 30625376 DOI: 10.1016/j.tiv.2019.01.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 12/21/2018] [Accepted: 01/04/2019] [Indexed: 10/27/2022]
Abstract
The inhibition of acetylcholinesterase (AChE) has pharmaceutical applications as well as potential neurotoxic effects. The in vivo metabolites of some chemicals including organophosphorus pesticides can become more potent AChE inhibitors compared to their parental compounds. To account for the effects of biotransformation, we have developed and characterized a high-throughput screening method for identifying AChE inhibitors that become active or more potent following xenobiotic metabolism. In this study, an enzyme-based assay was developed in 1536-well plates using recombinant human AChE combined with human or rat liver microsomes. The AChE activity was measured by two methods with different readouts: colorimetric and fluorescent. The assay exhibited exceptional performance characteristics including large assay signal window, low well-to-well variability and high reproducibility. The performance of the assays with microsomes was characterized by testing a group of known AChE inhibitors including parent compounds and their metabolites. Large potency differences between the parent compounds and the metabolites were observed in the assay with microsome addition. Both assay readouts were required for maximal sensitivity. These results demonstrate that this platform is a promising method to profile large numbers of chemicals that require metabolic activation for inhibiting AChE activity.
Collapse
Affiliation(s)
- Shuaizhang Li
- Division for Pre-Clinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, USA
| | - Jinghua Zhao
- Division for Pre-Clinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, USA
| | - Ruili Huang
- Division for Pre-Clinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, USA
| | - Michael F Santillo
- Division of Toxicology, Office of Applied Research and Safety Assessment, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, Laurel, MD, USA
| | - Keith A Houck
- National Center for Computational Toxicology, Office of Research and Development, United States Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Menghang Xia
- Division for Pre-Clinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, USA.
| |
Collapse
|
23
|
De Anna JS, Leggieri LR, Arias Darraz L, Cárcamo JG, Venturino A, Luquet CM. Effects of sequential exposure to water accommodated fraction of crude oil and chlorpyrifos on molecular and biochemical biomarkers in rainbow trout. Comp Biochem Physiol C Toxicol Pharmacol 2018; 212:47-55. [PMID: 30012402 DOI: 10.1016/j.cbpc.2018.07.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 07/03/2018] [Accepted: 07/05/2018] [Indexed: 01/09/2023]
Abstract
Fish can be simultaneously or sequentially exposed to various kinds of pollutants, resulting in combined effects. Polycyclic aromatic hydrocarbons induce cytochrome P450 monooxygenase 1A (CYP1A) expression, which catalyzes the conversion of the organophosphorus insecticide chlorpyrifos (CPF) into its most active derivative, CPF-oxon. CPF-oxon inhibits CYP1A and other enzymes, including carboxylesterases (CEs) and acetylcholinesterase (AChE). We studied the effects of an in vivo exposure to crude oil water accommodated fraction (WAF) followed by an ex vivo exposure of liver tissue to CPF on the expression of Cyp1a, AhR and ARNT mRNA, CYP1A protein and on the activity of biomarker enzymes in the rainbow trout (Oncorhynchus mykiss). Juvenile rainbow trout were exposed to WAF (62 μg L-1 TPH) for 48 h. Then, liver was dissected out, sliced and exposed to 20 μg L-1 CPF ex vivo for 1 h. Liver tissue was analyzed for mRNA and protein expression and for CEs, AChE, glutathione S-transferase (GST) and CYP1A (EROD) activity. WAF induced Cyp1a mRNA and CYP1A protein expression by 10-fold and 2.5-8.3-fold, respectively, with no effect of CPF. WAF induced AhR expression significantly (4-fold) in control but not in CPF treated liver tissue. ARNT mRNA expression was significantly lowered (5-fold) by WAF. CPF significantly reduced liver EROD activity, independently of WAF pre-treatment. CEs activity was significantly inhibited in an additive manner following in vivo exposure to WAF (42%) and ex vivo exposure to CPF (19%). CPF exposure inhibited AChE activity (37%) and increased GST activity (42%).
Collapse
Affiliation(s)
- Julieta S De Anna
- Laboratorio de Ecotoxicología Acuática, INIBIOMA- CONICET- CEAN, Ruta provincial 61, km 3, 8371 Junín de los Andes, Neuquén, Argentina.
| | - Leonardo R Leggieri
- Laboratorio de Ecotoxicología Acuática, INIBIOMA- CONICET- CEAN, Ruta provincial 61, km 3, 8371 Junín de los Andes, Neuquén, Argentina
| | - Luis Arias Darraz
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Campus Isla Teja, Valdivia, Chile
| | - Juan G Cárcamo
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Campus Isla Teja, Valdivia, Chile; Centro FONDAP, Interdisciplinary Center for Aquaculture Research (INCAR), Chile
| | - Andrés Venturino
- Centro de Investigaciones en Toxicología Ambiental y Agrobiotecnología del Comahue, CITAAC, UNCo-CONICET, Instituto de Biotecnología Agropecuaria del Comahue, Facultad de Ciencias Agrarias, Universidad Nacional del Comahue, Ruta 151, km 12, 8303 Cinco Saltos, Río Negro, Argentina
| | - Carlos M Luquet
- Laboratorio de Ecotoxicología Acuática, INIBIOMA- CONICET- CEAN, Ruta provincial 61, km 3, 8371 Junín de los Andes, Neuquén, Argentina.
| |
Collapse
|
24
|
Al-Attar AM, Elnaggar MH, Almalki EA. Physiological study on the influence of some plant oils in rats exposed to a sublethal concentration of diazinon. Saudi J Biol Sci 2018; 25:786-796. [PMID: 29740245 PMCID: PMC5936871 DOI: 10.1016/j.sjbs.2016.11.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 10/13/2016] [Accepted: 11/03/2016] [Indexed: 01/18/2023] Open
Abstract
The present study was aimed to evaluate the influence of olive, sesame and black seed oils on levels of some physiological parameters in male rats exposed to diazinon (DZN). Body weight changes, and levels of serum total protein, albumin, glucose, triglycerides, cholesterol, high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), very low density lipoprotein cholesterol (VLDL-C), atherogenic index (AI), atherogenic coefficient (AC), cardiac risk ratio (CRR), glutathione (GSH), superoxide dismutase (SOD) and malondialdehyde (MAD) were selected as physiological parameters. The experimental animals were distributed into nine groups. Rats group exposed to DZN and fed with normal diet resulted in pronounced severe changes including reduced body weight gain rate, significantly increase in levels of serum albumin, glucose, cholesterol, LDL-C, AI, AC, CRR and MDA while levels of HDL-C, GSH and SOD were decreased. In rats treated with DZN, the supplementation of the olive, sesame and black seed oils showed remarkable lowering influences of physiological alterations. Moreover, the present results confirmed that these oils possess antioxidative effects against DZN toxicity. Finally, the present findings suggest that these oils are safe and promising agents for the treatment of physiological disturbances induced by DZN and may be also by other pollutants, and toxic and pathogenic factors.
Collapse
Affiliation(s)
- Atef M. Al-Attar
- Department of Biological Sciences, Faculty of Sciences, King Abdulaziz University, P.O. Box 139109, Jeddah 21323, Saudi Arabia
| | | | | |
Collapse
|
25
|
Alejo-González K, Hanson-Viana E, Vazquez-Duhalt R. Enzymatic detoxification of organophosphorus pesticides and related toxicants. JOURNAL OF PESTICIDE SCIENCE 2018; 43:1-9. [PMID: 30363124 PMCID: PMC6140661 DOI: 10.1584/jpestics.d17-078] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 01/08/2018] [Indexed: 05/20/2023]
Abstract
Millions of cases of pesticide intoxication occur yearly and represent a public health problem. In addition, pesticide poisoning is the preferred suicidal method in rural areas. The use of enzymes for the treatment of intoxication due to organophosphorus pesticides was proposed decades ago. Several enzymes are able to transform organophosphorus compounds such as pesticides and nerve agents. Some specific enzymatic treatments have been proposed, including direct enzyme injection, liposome and erythrocytes carriers, PEGylated preparations and extracorporeal enzymatic treatments. Nevertheless, no enzymatic treatments are currently available. In this work, the use of enzymes for treating of organophosphorus pesticide intoxication is critically reviewed and the remaining challenges are discussed.
Collapse
Affiliation(s)
- Karla Alejo-González
- Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Km 107 carretera Tijuana-Ensenada, Ensenada, Baja California 22760 México
| | - Erik Hanson-Viana
- Facultad de Medicina, Universidad Autónoma de Baja California, Mexicali, Mexico
| | - Rafael Vazquez-Duhalt
- Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Km 107 carretera Tijuana-Ensenada, Ensenada, Baja California 22760 México
| |
Collapse
|
26
|
Nili-Ahmadabadi A, Alibolandi P, Ranjbar A, Mousavi L, Nili-Ahmadabadi H, Larki-Harchegani A, Ahmadimoghaddam D, Omidifar N. Thymoquinone attenuates hepatotoxicity and oxidative damage caused by diazinon: an in vivo study. Res Pharm Sci 2018; 13:500-508. [PMID: 30607148 PMCID: PMC6288994 DOI: 10.4103/1735-5362.245962] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Thymoquinone (TQ) is the main active constituent of Nigella sativa seeds. The objective of this study was to explore the protective effects of TQ on diazinon (DZN)-induced liver toxicity in the mouse model. The animals were divided into five groups of 6 each and treated intraperitoneally. Group 1 received the vehicle, group 2 was given 16 mg/kg DZN, group 3 received 5 mg/kg TQ, and groups 4 and 5 were treated with 1.25 and 5 mg/kg of TQ as well as 16 mg/kg DZN, respectively. Finally, butyrylcholinesterase (BChE), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) serum activity as well as nitric oxide (NO), lipid peroxidation (LPO), total antioxidant capacity (TAC), total thiol molecule (TTM), and histopathological experiments were evaluated in the liver samples. Our findings showed that DZN caused a significant increase in ALT (P < 0.01), AST (P < 0.001), ALP (P < 0.001) serum levels, LPO (P < 0.001) and NO (P < 0.001), the depletion of the TAC (P < 0.05) and TTM (P < 0.001), and structural changes in the liver tissue. Following TQ administration, a significant improvement was observed in the oxidative stress biomarkers in the liver tissue. In addition, our biochemical findings were correlated well to the histopathological examinations. In conclusion, the data from this study indicate that the administration of TQ may prevent liver damage by preventing free radical formation in animals exposed to DZN.
Collapse
Affiliation(s)
- Amir Nili-Ahmadabadi
- Medicinal Plants and Natural Products Research Center, Hamadan University of Medical Sciences, Hamadan, I.R. Iran.,Department of Pharmacology and Toxicology, School of Pharmacy, Hamadan University of Medical Sciences, Hamadan, I.R. Iran
| | - Parisa Alibolandi
- Medicinal Plants and Natural Products Research Center, Hamadan University of Medical Sciences, Hamadan, I.R. Iran.,Department of Pharmacology and Toxicology, School of Pharmacy, Hamadan University of Medical Sciences, Hamadan, I.R. Iran
| | - Akram Ranjbar
- Medicinal Plants and Natural Products Research Center, Hamadan University of Medical Sciences, Hamadan, I.R. Iran.,Department of Pharmacology and Toxicology, School of Pharmacy, Hamadan University of Medical Sciences, Hamadan, I.R. Iran
| | - Leila Mousavi
- Department of Clinical Sciences, School of Medical Sciences, Hamadan University of Medical Sciences, Hamadan, I.R. Iran
| | - Hossein Nili-Ahmadabadi
- Department of Internal Medicine and Gastroenterology, School of Medicine, Yasuj University of Medical Sciences, Yasuj, I.R. Iran
| | - Amir Larki-Harchegani
- Medicinal Plants and Natural Products Research Center, Hamadan University of Medical Sciences, Hamadan, I.R. Iran.,Department of Pharmacology and Toxicology, School of Pharmacy, Hamadan University of Medical Sciences, Hamadan, I.R. Iran
| | - Davoud Ahmadimoghaddam
- Medicinal Plants and Natural Products Research Center, Hamadan University of Medical Sciences, Hamadan, I.R. Iran.,Department of Pharmacology and Toxicology, School of Pharmacy, Hamadan University of Medical Sciences, Hamadan, I.R. Iran
| | - Navid Omidifar
- Department of Pathology, School of Medicine, and Clinical education Research center, Shiraz University of Medical Sciences, Shiraz, I.R. Iran
| |
Collapse
|
27
|
Imaishi H, Goto T. Effect of genetic polymorphism of human CYP2B6 on the metabolic activation of chlorpyrifos. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2018; 144:42-48. [PMID: 29463407 DOI: 10.1016/j.pestbp.2017.11.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 10/05/2017] [Accepted: 11/09/2017] [Indexed: 06/08/2023]
Abstract
Chlorpyrifos (CPS) is a broad-spectrum organophosphate insecticide that is neurotoxic in humans. Chlorpyrifos oxon (CPO) is a toxic metabolite of CPS that is produced by CYP2B6. In this study, we examined the variability of CPS metabolism resulting from single-nucleotide polymorphisms in CYP2B6. Wild-type CYP2B6 (CYP2B6.1) and two variants each with a single amino acid substitution: CYP2B6.5 (R487C) and CYP2B6.8 (K139E) were co-expressed together with human NADPH-dependent cytochrome P450 reductase in Escherichia coli (E. coli). Both of the CYP2B6 variants were successfully expressed in E. coli. The conversion of CPS to CPO by the CYP2B6 variants was analyzed with high-performance liquid chromatography. Km and Vmax of the reaction by CYP2B6.1 were 18.50±2.94μM and 17.07±1.15mol/min/mol P450, respectively. The CYP2B6 variants produced CPO with the following kinetic parameters: Km for CYP2B6.5 and CYP2B6.8 were 20.44±6.43 and 44.69±9.97μM, respectively; and Vmax were 1.10±0.10 and 1.77±0.26mol/min/mol P450, respectively. These results indicate that the amino acid substitutions in the CYP2B6 variants suppressed the metabolic activation of CPS. CYP2B6 variants have altered capacity to bioactivate CPF and may affect individual susceptibility of CPF.
Collapse
Affiliation(s)
- Hiromasa Imaishi
- Laboratory of Response to Environmental Materials, Division of Signal Responses, Biosignal Research Center, Kobe University, Nada-ku, Kobe, Hyogo 657-8501, Japan.
| | - Tatsushi Goto
- Laboratory of Response to Environmental Materials, Division of Signal Responses, Biosignal Research Center, Kobe University, Nada-ku, Kobe, Hyogo 657-8501, Japan
| |
Collapse
|
28
|
Prediction of regioselectivity and preferred order of metabolisms on CYP1A2-mediated reactions. Part 2: Solving substrate interactions of CYP1A2 with non-PAH substrates on the template system. Drug Metab Pharmacokinet 2017; 32:229-247. [DOI: 10.1016/j.dmpk.2017.05.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 04/19/2017] [Accepted: 05/17/2017] [Indexed: 01/02/2023]
|
29
|
Ginsberg G, Vulimiri SV, Lin YS, Kancherla J, Foos B, Sonawane B. A framework and case studies for evaluation of enzyme ontogeny in children's health risk evaluation. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2017; 80:569-593. [PMID: 28891786 PMCID: PMC8018602 DOI: 10.1080/15287394.2017.1369915] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Knowledge of the ontogeny of Phase I and Phase II metabolizing enzymes may be used to inform children's vulnerability based upon likely differences in internal dose from xenobiotic exposure. This might provide a qualitative assessment of toxicokinetic (TK) variability and uncertainty pertinent to early lifestages and help scope a more quantitative physiologically based toxicokinetic (PBTK) assessment. Although much is known regarding the ontogeny of metabolizing systems, this is not commonly utilized in scoping and problem formulation stage of human health risk evaluation. A framework is proposed for introducing this information into problem formulation which combines data on enzyme ontogeny and chemical-specific TK to explore potential child/adult differences in internal dose and whether such metabolic differences may be important factors in risk evaluation. The framework is illustrated with five case study chemicals, including some which are data rich and provide proof of concept, while others are data poor. Case studies for toluene and chlorpyrifos indicate potentially important child/adult TK differences while scoping for acetaminophen suggests enzyme ontogeny is unlikely to increase early-life risks. Scoping for trichloroethylene and aromatic amines indicates numerous ways that enzyme ontogeny may affect internal dose which necessitates further evaluation. PBTK modeling is a critical and feasible next step to further evaluate child-adult differences in internal dose for a number of these chemicals.
Collapse
Affiliation(s)
- Gary Ginsberg
- Partnership in Pediatric and Environmental Health, Hartford, CT 06134, USA
| | - Suryanarayana V. Vulimiri
- National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Washington, DC 20460, USA
| | - Yu-Sheng Lin
- National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Washington, DC 20460, USA
| | - Jayaram Kancherla
- Center for Bioinformatics and Computational Biology, University of Maryland, College Park, MD, 20740, USA
| | - Brenda Foos
- Office of Children’s Health Protection, U.S. Environmental Protection Agency, Washington, DC, USA
| | - Babasaheb Sonawane
- National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Washington, DC 20460, USA
- Current Address: 13204 Moran Drive, North Potomac, MD 20878
| |
Collapse
|
30
|
Jafari F, Samadi S, Nowroozi A, Sadrjavadi K, Moradi S, Ashrafi-Kooshk MR, Shahlaei M. Experimental and computational studies on the binding of diazinon to human serum albumin. J Biomol Struct Dyn 2017; 36:1490-1510. [DOI: 10.1080/07391102.2017.1329096] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Fataneh Jafari
- Pharmaceutical Sciences Research Center, School of Pharmacy, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Setareh Samadi
- Department of Toxicology, Shahreza Branch, Islamic Azad University, Shaahreza, Iran
| | - Amin Nowroozi
- Pharmaceutical Sciences Research Center, School of Pharmacy, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Komail Sadrjavadi
- Pharmaceutical Sciences Research Center, School of Pharmacy, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Sajad Moradi
- Nano Drug Delivery Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | | | - Mohsen Shahlaei
- Nano Drug Delivery Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran
| |
Collapse
|
31
|
Spodniewska A, Barski D, Giżejewska A. Effect of enrofloxacin and chlorpyrifos on the levels of vitamins A and E in Wistar rats. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2015; 40:587-591. [PMID: 26356388 DOI: 10.1016/j.etap.2015.08.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 08/13/2015] [Accepted: 08/16/2015] [Indexed: 06/05/2023]
Abstract
This study investigates the effects of enrofloxacin and chlorpyrifos, and their combination on vitamin A and E concentrations in the liver of rats. Results of this study indicated a reduction in the contents of vitamins A and E in the liver, which persisted for the entire period of the experiment. Vitamins A and E concentrations were slightly decreased (2-7%) in enrofloxacin-treated rats. In the group of rats intoxicated with chlorpyrifos, a significant decrease in the level of vitamin A was observed up to the 24th hour, and for vitamin E up to the 3rd day from the discontinuation of intoxication with the compounds under study. In the enrofloxacin-chlorpyrifos co-exposure group reduced vitamins A and E level was also noted. The greatest fall in vitamin A level was observed after 3h, while the contents of vitamin E decreased progressively up to the 3rd day. Changes in this group were less pronounced in comparison to the animals intoxicated with chlorpyrifos only.
Collapse
Affiliation(s)
- Anna Spodniewska
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, M. Oczapowskiego 14 Street, 10-719 Olsztyn, Poland.
| | - Dariusz Barski
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, M. Oczapowskiego 14 Street, 10-719 Olsztyn, Poland.
| | - Aleksandra Giżejewska
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, M. Oczapowskiego 14 Street, 10-719 Olsztyn, Poland.
| |
Collapse
|
32
|
D'Agostino J, Zhang H, Kenaan C, Hollenberg PF. Mechanism-Based Inactivation of Human Cytochrome P450 2B6 by Chlorpyrifos. Chem Res Toxicol 2015; 28:1484-95. [PMID: 26075493 DOI: 10.1021/acs.chemrestox.5b00156] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Chlorpyrifos (CPS) is a commonly used pesticide which is metabolized by P450s into the toxic metabolite chlorpyrifos-oxon (CPO). Metabolism also results in the release of sulfur, which has been suggested to be involved in mechanism-based inactivation (MBI) of P450s. CYP2B6 was previously determined to have the greatest catalytic efficiency for CPO formation in vitro. Therefore, we characterized the MBI of CYP2B6 by CPS. CPS inactivated CYP2B6 in a time- and concentration-dependent manner with a kinact of 1.97 min(-1), a KI of 0.47 μM, and a partition ratio of 17.7. We further evaluated the ability of other organophosphate pesticides including chorpyrifos-methyl, diazinon, parathion-methyl, and azinophos-methyl to inactivate CYP2B6. These organophosphate pesticides were also potent MBIs of CYP2B6 characterized by similar kinact and KI values. The inactivation of CYP2B6 by CPS was accompanied by the loss of P450 detectable in the CO reduced spectrum and loss of detectable heme. High molecular weight aggregates were observed when inactivated CYP2B6 was run on SDS-PAGE gels indicating protein aggregation. Interestingly, we found that the rat homologue of CYP2B6, CYP2B1, was not inactivated by CPS despite forming CPO to a similar extent. On the basis of the locations of the Cys residues in the two proteins which could react with released sulfur during the metabolism of CPS, we investigated whether the C475 in CYP2B6, which is not conserved in CYP2B1, was the critical residue for inactivation by mutating it to a Ser. CYP2B6 C475S was inactivated to a similar extent as wild type CYP2B6 indicating that C475 is not likely the key difference between CYP2B1 and CYP2B6 with respect to inactivation. These results indicate that CPS and other organophosphate pesticides are potent MBIs of CYP2B6 which may have implications for the toxicity of these pesticides as well as the potential for pesticide-drug interactions.
Collapse
Affiliation(s)
- Jaime D'Agostino
- Department of Pharmacology, University of Michigan, 2220C MSRB III, 1150 W. Medical Center Drive, Ann Arbor, Michigan 48109-5632, United States
| | - Haoming Zhang
- Department of Pharmacology, University of Michigan, 2220C MSRB III, 1150 W. Medical Center Drive, Ann Arbor, Michigan 48109-5632, United States
| | - Cesar Kenaan
- Department of Pharmacology, University of Michigan, 2220C MSRB III, 1150 W. Medical Center Drive, Ann Arbor, Michigan 48109-5632, United States
| | - Paul F Hollenberg
- Department of Pharmacology, University of Michigan, 2220C MSRB III, 1150 W. Medical Center Drive, Ann Arbor, Michigan 48109-5632, United States
| |
Collapse
|
33
|
Ma J, Liu Y, Niu D, Li X. Effects of chlorpyrifos on the transcription of CYP3A cDNA, activity of acetylcholinesterase, and oxidative stress response of goldfish (Carassius auratus). ENVIRONMENTAL TOXICOLOGY 2015; 30:422-429. [PMID: 24190793 DOI: 10.1002/tox.21918] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 10/10/2013] [Accepted: 10/14/2013] [Indexed: 06/02/2023]
Abstract
Chlorpyrifos (CPF) is the widely used organophosphate pesticide in agriculture throughout the world. It has been found that CPF is relatively safe to human but highly toxic to fish. In this study, acute toxicity of CPF on goldfish was determined and then the transcription of goldfish cytochrome P450 (CYP) 3A was evaluated after 96 h of CPF exposure at concentrations of 15.3 [1/10 50% lethal concentration (LC50 )] or 51 μg L(-1) (1/3 LC50 ) of CPF. Meanwhile, the enzymatic activities of acetylcholinesterase (AChE), superoxide dismutase (SOD), and catalase (CAT), total antioxidant activity (T-AOC), and the contents of malondialdehyde (MDA) in the liver or brain of goldfish were also determined. The results of acute toxicity testing showed that the 96-h LC50 of CPF to the goldfish was 153 μg L(-1) . Moreover, a length sequence of 1243 bp CYP3A cDNA encoding for 413 amino acids from goldfish liver was cloned. Polymerase chain reaction results reveal that CPF exposure downregulates CYP 3A transcription in goldfish liver, suggesting that goldfish CYP 3A may be not involved in CPF bioactivation. Finally, the results of biochemical assays indicate that 96 h of CPF exposure remarkably inhibits AChE activity in fish liver or brain, alters hepatic antioxidant enzyme activities, decreases brain T-AOC, and causes lipid peroxidation in fish liver. These results suggest that oxidative stress might be involved in CPF toxicity on goldfish.
Collapse
Affiliation(s)
- Junguo Ma
- College of Life Science, Henan Normal University, Xinxiang, Henan, 453007, China
| | | | | | | |
Collapse
|
34
|
Food safety in Thailand 1: it is safe to eat watermelon and durian in Thailand. Environ Health Prev Med 2015; 20:204-15. [PMID: 25697579 DOI: 10.1007/s12199-015-0452-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 02/09/2015] [Indexed: 02/02/2023] Open
Abstract
OBJECTIVES The wide use of pesticides raises serious concerns regarding food safety and environmental impacts. There is increasing public concern about the potential health risks linked with exposure to pesticides. Regulation of maximum residue limits (MRL) of pesticide residues in food commodities has been established in many developed countries. For developing countries, like Thailand, this regulation often exists in law, but is not completely enforced in practice. Thus, pesticide residue levels in vegetables and fruits have not been thoroughly monitored. The present study aimed to examine potential health risks associated with pesticide exposure by determining the pesticide residues in two commonly consumed fruits, watermelon and durian. METHODS The fruit samples were purchased from markets in central provinces of Thailand and assayed for the content of 28 pesticides. Analysis of pesticides was performed by multiresidue extraction and followed by GC-MS/MS detection. RESULTS Of 28 pesticides investigated, 5 were detected in 90.7% of the watermelon samples (n = 75) and 3 in 90% of durian samples (n = 30). Carbofuran, chlorpyrifos, diazinon, dimethoate and metalaxyl were found in watermelons, whereas dichlorvos, dimethoate and metalaxyl were detected in durians. However, their levels were much lower than the recommended MRL values. CONCLUSIONS These pesticide levels detected in the fruits are unlikely to harm the consumers; therefore it is safe to eat watermelon and durian in Thailand. While our results found negligible risk associated with pesticide exposure from consuming these common tropical fruits, special precautions should be considered to decrease total exposure to these harmful pesticides from various foods.
Collapse
|
35
|
Abdel-Daim MM. Synergistic protective role of ceftriaxone and ascorbic acid against subacute diazinon-induced nephrotoxicity in rats. Cytotechnology 2014; 68:279-89. [PMID: 25150555 DOI: 10.1007/s10616-014-9779-z] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 07/31/2014] [Indexed: 01/10/2023] Open
Abstract
Diazinon (DZN) is a synthetic organophosphrus acaricide and insecticide widely used for veterinary and agricultural purposes. However, its animal and human exposure leads to nephrotoxicity. Our experimental objective was to evaluate protective effects of ceftriaxone and/or ascorbic acid-vitamin C against DZN-induced renal injury in male Wistar albino rats. DZN-treated animals revealed significant elevation in serum biochemical parameters related to renal injury: urea, uric acid and creatinine. DZN intoxication significantly increased renal lipid peroxidation, and significant inhibition in antioxidant biomarkers including, reduced glutathione, glutathione peroxidase, superoxide dismutase, catalase and total antioxidant capacity. In addition, DZN significantly reduced serum acetylcholinestrase level. Moreover, It induced serum and kidney tumor necrosis factor-α level. Both ceftriaxone and vitamin C protect against DZN-induced serum as well as renal tissue biochemical parameters when used alone or in combination along with DZN-intoxication. Furthermore, both ceftriaxone and vitamin C produced synergetic nephroprotective and antioxidant effects. Therefore, it could be concluded that ceftriaxone and/or vitamin C administration are able to minimize the toxic effects of DZN by its free radical-scavenging and potent antioxidant activity.
Collapse
Affiliation(s)
- Mohamed M Abdel-Daim
- Pharmacology Department, Faculty of Veterinary Medicine, Suez Canal University, Ismailia, 41522, Egypt.
| |
Collapse
|
36
|
A human life-stage physiologically based pharmacokinetic and pharmacodynamic model for chlorpyrifos: Development and validation. Regul Toxicol Pharmacol 2014; 69:580-97. [DOI: 10.1016/j.yrtph.2013.10.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 10/18/2013] [Accepted: 10/19/2013] [Indexed: 12/25/2022]
|
37
|
Santos MG, Vitor RV, Nakamura MG, Morelini LDS, Ferreira RS, Paiva AG, Azevedo L, Marques VBB, Martins I, Figueiredo EC. Study of the correlation between blood cholinesterases activity, urinary dialkyl phosphates, and the frequency of micronucleated polychromatic erythrocytes in rats exposed to disulfoton. BRAZ J PHARM SCI 2013. [DOI: 10.1590/s1984-82502013000100016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Organophosphates (OPs) are widely used as pesticides, and its urinary metabolites as well as the blood cholinesterases (ChEs) activity have been reported as possible biomarkers for the assessment of this pesticide exposure. Moreover, the OPs can induce mutagenesis, and the bone marrow micronucleus test is an efficient way to assess this chromosomal damage. This paper reports a study carried out to verify the correlation among the disulfoton exposure, blood ChEs activity, urinary diethyl thiophosphate (DETP), and diethyl dithiophosphate (DEDTP), as well as micronucleated polychromatic erythrocytes (MNPCEs) frequency. Four groups of rats (n=12) were exposed to disulfoton at 0, 2.8, 4.7, and 6.6 mg kg-1 body weight. The blood ChEs activity, urinary DETP and DEDTP concentrations, and MNPCEs frequency were determined. It was observed that the plasmatic and erythrocytary ChEs activity decreased from 2.9% to 0.5% and from 35.9 to 3.3%, respectively, when the disulfoton dose was increased from 0 to 6.6 mg kg-1 (correlation of 0.99). Urinary DETP and DEDTP concentrations, as well as the MNPCEs frequency, increased from 0 to 6.58 µg mL-1, from 0 to 0.04 µg mL-1, and from 0 to 1.4%, respectively, when the disulfoton dose was increased from 0 to 6.58 mg kg-1 body weight.
Collapse
|
38
|
Abstract
Chlorpyrifos (CPF), an organophosphorus (OP) pesticide, is bioactivated by cytochrome P450s (CYPs) to the active metabolite chlorpyrifos oxon (CPF-O). Given that human CYP2B6 has the highest intrinsic clearance (CL(int)) for CPF bioactivation, CYP2B6 polymorphisms may impact human susceptibility to CPF at real world environmental and occupational CPF exposure levels. CYP2B6.4,.5,.7, and .18 were over-expressed in mammalian COS-1 cells to assess the impact of CYP2B6 variants on the K(m) and V(max) for bioactivation of CPF. Cell lysates were incubated with CPF (0-100 μM) and the production of CPF-O was measured via HPLC analysis. CYP2B6 content was determined by western blot. CYP2B6.18 had neither detectable protein nor activity levels. The V(max) value for each remaining variant was significantly higher than wild-type (CYP2B6.1, V(max) 4.13 × 10(4) pmol/min/nmol CYP2B6), with CYP2B6.4,.5, and .7 having V(max) values of 4.52 × 10(5), 1.82 × 10(5), and 9.60 × 10(4) pmol/min/nmol CYP2B6, respectively. The K(m) values for these variants ranged from 0.39 to 1.09 μM and were not significantly different from wild-type. All active variants examined had significantly higher CL(int) than CYP2B6.1. Variants of CYP2B6 have altered capacity to bioactivate CPF and may affect individual susceptibility by altering the V(max) for CPF-O formation.
Collapse
Affiliation(s)
- Alice L Crane
- Department of Pharmacology and Toxicology, State University of New York at Buffalo, Buffalo, NY, USA
| | | | | |
Collapse
|
39
|
Erratico CA, Szeitz A, Bandiera SM. Oxidative Metabolism of BDE-99 by Human Liver Microsomes: Predominant Role of CYP2B6. Toxicol Sci 2012; 129:280-92. [DOI: 10.1093/toxsci/kfs215] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
40
|
Crane AL, Klein K, Zanger UM, Olson JR. Effect of CYP2B6*6 and CYP2C19*2 genotype on chlorpyrifos metabolism. Toxicology 2012; 293:115-122. [PMID: 22281205 DOI: 10.1016/j.tox.2012.01.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Revised: 01/09/2012] [Accepted: 01/10/2012] [Indexed: 01/11/2023]
Abstract
Chlorpyrifos (CPF) is a widely used organophosphorus (OP) pesticide. CPF is bioactivated by cytochrome P450s (CYPs) to the potent cholinesterase inhibitor chlorpyrifos oxon (CPF-O) or detoxified to 3,5,6-trichloro-2-pyridinol (TCPy). Human CYP2B6 has the highest reported Vmax)/Km (intrinsic clearance--CL(int)) for bioactivation while CYP2C19 has the highest reported CL(int) for detoxification of CPF. In this study, 22 human liver microsomes (HLMs) genotyped for common variants of these enzymes (CYP2B6*6 and CYP2C19*2) were incubated with 10 μM and 0.5 μM CPF and assayed for metabolite production. While no differences in metabolite production were observed in homozygous CYP2C19*2 HLMs, homozygous CYP2B6*6 specimens produced significantly less CPF-O than wild-type specimens at 10 μM (mean 144 and 446 pmol/min/mg, respectively). This correlated with reduced expression of CYP2B6 protein (mean 4.86 and 30.1 pmol/mg, for CYP2B6*6 and *1, respectively). Additionally, CYP2B6*1 and CYP2B6*6 were over-expressed in mammalian COS-1 cells to assess for the first time the impact of the CYP2B6*6 variant on the kinetic parameters of CPF bioactivation. The Vmax for CYP2B6*6 (1.05×10⁵ pmol/min/nmol CYP2B6) was significantly higher than that of CYP2B6*1 (4.13×10⁴ pmol/min/nmol CYP2B6) but the K(m) values did not differ (1.97 μM for CYP2B6*6 and 1.84 μM for CYP2B6*1) resulting in CL(int) rates of 53.5 and 22.5 nL/min/nmol CYP2B6 for *6 and *1, respectively. These data suggest that CYP2B6*6 has increased specific activity but reduced capacity to bioactivate CPF in HLMs compared to wild-type due to reduced hepatic protein expression, indicating that individuals with this genotype may be less susceptible to CPF toxicity.
Collapse
Affiliation(s)
- Alice L Crane
- Department of Pharmacology and Toxicology, State University of New York at Buffalo, Buffalo, NY 14214, USA.
| | - Kathrin Klein
- Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology, Auerbachstr. 112, 70376 Stuttgart, Germany.
| | - Ulrich M Zanger
- Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology, Auerbachstr. 112, 70376 Stuttgart, Germany; Department of Clinical Pharmacology, University of Tuebingen, Tuebingen, Germany.
| | - James R Olson
- Department of Pharmacology and Toxicology, State University of New York at Buffalo, Buffalo, NY 14214, USA.
| |
Collapse
|
41
|
Singh S, Kumar V, Singh P, Banerjee BD, Rautela RS, Grover SS, Rawat DS, Pasha ST, Jain SK, Rai A. Influence of CYP2C9, GSTM1, GSTT1 and NAT2 genetic polymorphisms on DNA damage in workers occupationally exposed to organophosphate pesticides. Mutat Res 2011; 741:101-8. [PMID: 22108250 DOI: 10.1016/j.mrgentox.2011.11.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Revised: 10/09/2011] [Accepted: 11/07/2011] [Indexed: 10/15/2022]
Abstract
Previous studies have revealed that organophosphate pesticides (OPs) are primarily metabolized by xenobiotic metabolizing enzymes (XMEs). Very few studies have explored genetic polymorphisms of XMEs and their association with DNA damage in pesticides-exposed workers. Present study was designed to determine the influence of CYP2C9, GSTM1, GSTT1 and NAT2 genetic polymorphisms on DNA damage in workers occupationally exposed to OPs. We examined 268 subjects including 134 workers occupationally exposed to OPs and an equal number of normal healthy controls. The DNA damage was evaluated using alkaline comet assay and genotyping was done using individual polymerase chain reaction (PCR) or polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Acetylcholinesterase and paraoxonase activity were found to be significantly lowered in workers as compared to control subjects which were analyzed as biomarkers of toxicity due to OPs exposure (p<0.001). Workers showed significantly higher DNA tail moment (TM) compared to control subjects (14.32±2.17 vs. 6.24±1.37 tail % DNA, p<0.001). GSTM1 null genotype was found to influence DNA TM in workers (p<0.05). DNA TM was also found to be increased with concomitant presence of NAT2 slow acetylation and CYP2C9*3/*3 or GSTM1 null genotypes (p<0.05). DNA TM was found increased in NAT2 slow acetylators with mild and heavy smoking habits in control subjects and workers, respectively (p<0.05). The results of this study suggest that GSTM1 null genotypes, and an association of NAT2 slow acetylation genotypes with CYP2C9*3/*3 or GSTM1 null genotypes may modulate DNA damage in workers occupationally exposed to OPs.
Collapse
Affiliation(s)
- Satyender Singh
- Division of Biochemistry & Biotechnology, National Centre for Disease Control, 22, Sham Nath Marg, Delhi 110054, India.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Ellison CA, Tian Y, Knaak JB, Kostyniak PJ, Olson JR. Human hepatic cytochrome P450-specific metabolism of the organophosphorus pesticides methyl parathion and diazinon. Drug Metab Dispos 2011; 40:1-5. [PMID: 21969518 DOI: 10.1124/dmd.111.042572] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Organophosphorus pesticides (OPs) are a public health concern due to their worldwide use and documented human exposures. Phosphorothioate OPs are metabolized by cytochrome P450s (P450s) through either a dearylation reaction to form an inactive metabolite, or through a desulfuration reaction to form an active oxon metabolite, which is a potent cholinesterase inhibitor. This study investigated the rate of desulfuration (activation) and dearylation (detoxification) of methyl parathion and diazinon in human liver microsomes. In addition, recombinant human P450s were used to determine the P450-specific kinetic parameters (K(m) and V(max)) for each compound for future use in refining human physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) models of OP exposure. The primary enzymes involved in bioactivation of methyl parathion were CYP2B6 (K(m) = 1.25 μM; V(max) = 9.78 nmol · min(-1) · nmol P450(-1)), CYP2C19 (K(m) = 1.03 μM; V(max) = 4.67 nmol · min(-1) · nmol P450(-1)), and CYP1A2 (K(m) = 1.96 μM; V(max) = 5.14 nmol · min(-1) · nmol P450(-1)), and the bioactivation of diazinon was mediated primarily by CYP1A1 (K(m) = 3.05 μM; V(max) = 2.35 nmol · min(-1) · nmol P450(-1)), CYP2C19 (K(m) = 7.74 μM; V(max) = 4.14 nmol · min(-1) · nmol P450(-1)), and CYP2B6 (K(m) = 14.83 μM; V(max) = 5.44 nmol · min(-1) · nmol P450(-1)). P450-mediated detoxification of methyl parathion only occurred to a limited extent with CYP1A2 (K(m) = 16.8 μM; V(max) = 1.38 nmol · min(-1) · nmol P450(-1)) and 3A4 (K(m) = 104 μM; V(max) = 5.15 nmol · min(-1) · nmol P450(-1)), whereas the major enzyme involved in diazinon detoxification was CYP2C19 (K(m) = 5.04 μM; V(max) = 5.58 nmol · min(-1) · nmol P450(-1)). The OP- and P450-specific kinetic values will be helpful for future use in refining human PBPK/PD models of OP exposure.
Collapse
Affiliation(s)
- Corie A Ellison
- University at Buffalo, Department of Pharmacology and Toxicology, 3435 Main Street, Buffalo, NY 14214, USA
| | | | | | | | | |
Collapse
|
43
|
Singh S, Kumar V, Vashisht K, Singh P, Banerjee BD, Rautela RS, Grover SS, Rawat DS, Pasha ST, Jain SK, Rai A. Role of genetic polymorphisms of CYP1A1, CYP3A5, CYP2C9, CYP2D6, and PON1 in the modulation of DNA damage in workers occupationally exposed to organophosphate pesticides. Toxicol Appl Pharmacol 2011; 257:84-92. [PMID: 21907728 DOI: 10.1016/j.taap.2011.08.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Revised: 08/12/2011] [Accepted: 08/22/2011] [Indexed: 12/13/2022]
Abstract
Organophosphate pesticides (OPs) are primarily metabolized by several xenobiotic metabolizing enzymes (XMEs). Very few studies have explored genetic polymorphisms of XMEs and their association with DNA damage in pesticide-exposed workers. The present study was designed to determine the role of genetic polymorphisms of CYP1A1, CYP3A5, CYP2C9, CYP2D6, and PON1 in the modulation of DNA damage in workers occupationally exposed to OPs. We examined 284 subjects including 150 workers occupationally exposed to OPs and 134 normal healthy controls. The DNA damage was evaluated using the alkaline comet assay and genotyping was done using PCR-RFLP. The results revealed that the PONase activity toward paraoxonase and AChE activity was found significantly lowered in workers as compared to control subjects (p<0.001). Workers showed significantly higher DNA damage compared to control subjects (14.37±2.15 vs. 6.24±1.37 tail% DNA, p<0.001). Further, the workers with CYP2D6*3PM and PON1 (QQ and MM) genotypes were found to have significantly higher DNA damage when compared to other genotypes (p<0.05). In addition, significant increase in DNA damage was also observed in workers with concomitant presence of certain CYP2D6 and PON1 (Q192R and L55M) genotypes which need further extensive studies. In conclusion, the results indicate that the PON1 and CYP2D6 genotypes can modulate DNA damage elicited by some OPs possibly through gene-environment interactions.
Collapse
Affiliation(s)
- Satyender Singh
- Division of Biochemistry & Biotechnology, National Centre for Disease Control 22, Sham Nath Marg, Delhi-110054, India
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Singh S, Kumar V, Singh P, Thakur S, Banerjee BD, Rautela RS, Grover SS, Rawat DS, Pasha ST, Jain SK, Rai A. Genetic polymorphisms of GSTM1, GSTT1 and GSTP1 and susceptibility to DNA damage in workers occupationally exposed to organophosphate pesticides. Mutat Res 2011; 725:36-42. [PMID: 21736951 DOI: 10.1016/j.mrgentox.2011.06.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Revised: 05/23/2011] [Accepted: 06/22/2011] [Indexed: 11/28/2022]
Abstract
GSTM1, T1 and P1 are important enzymes of glutathione S-transferases (GSTs), involved in the metabolism of many endogenous and exogenous compounds. Individual genetic variation in these metabolizing enzymes may influence the metabolism of their substrates. The present study was designed to determine the genotoxic effects using DNA damage and its association with GSTM1, GSTT1, and GSTP1 (Ile105Val) genetic polymorphisms in workers occupationally exposed to organophosphate pesticides (OPs). We examined 230 subjects including 115 workers occupationally exposed to OPs and an equal number of normal healthy controls. The DNA damage was evaluated using the alkaline comet assay and genotyping was done using individual PCR or PCR-RFLP. Significantly higher DNA tail moment (TM) was observed in workers as compared to control subjects (14.41 ± 2.25 vs. 6.36 ± 1.41 tail % DNA, p<0.001). The results revealed significantly higher DNA TM in workers with GSTM1 null genotype than those with GSTM1 positive (15.18 vs. 14.15 tail % DNA, p=0.03). A significantly higher DNA TM was also observed in workers with homozygous Ile-Ile GSTP1 genotype than heterozygous (Ile-Val) and mutant (Val-Val) GSTP1 genotype (p=0.02). In conclusion, the results show that null deletion of GSTM1 and homozygote wild GSTP1 genotype could be related to inter-individual differences in DNA damage arises from the gene-environment interactions in workers occupationally exposed to OPs.
Collapse
Affiliation(s)
- Satyender Singh
- Division of Biochemistry and Biotechnology, National Centre for Disease Control, 22, Sham Nath Marg, Delhi 110054, India
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Smith JN, Timchalk C, Bartels MJ, Poet TS. In vitro age-dependent enzymatic metabolism of chlorpyrifos and chlorpyrifos-oxon in human hepatic microsomes and chlorpyrifos-oxon in plasma. Drug Metab Dispos 2011; 39:1353-62. [PMID: 21521795 DOI: 10.1124/dmd.111.038745] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Age-dependent chlorpyrifos (CPF) metabolism was quantified by in vitro product formation in human hepatic microsomes (ages 13 days to 75 years) and plasma (ages 3 days to 43 years) with gas chromatography-mass spectrometry. Hepatic CPF cytochrome P450 desulfuration [CPF to chlorpyrifos-oxon (CPF-oxon)] and dearylation (CPF to 3,5,6-trichloro-2-pyridinol) V(max) values were 0.35 ± 0.21 and 0.73 ± 0.38 nmol · min(-1) · mg microsomal protein (-1) (mean ± S.D.), respectively. The mean (±S.D.) hepatic CPF-oxon hydrolysis (chlorpyrifos-oxonase [CPFOase]) V(max) was 78 ± 44 nmol · min(-1) · mg microsomal protein (-1). None of these hepatic measures demonstrated age-dependent relationships on a per microsomal protein basis using linear regression models. Ratios of CPF bioactivation to detoxification (CPF desulfuration to dearylation) V(max) values were consistent across ages. CPFOase in plasma demonstrated age-dependent increases on a volume of plasma basis, as did total plasma protein levels. Mean (±S.D.) CPF-oxon hydrolysis V(max) values for children <6 months of age and adults (≥16 years) were 1900 ± 660 and 6800 ± 1600 nmol · min(-1) · ml(-1), respectively, and at environmental exposure levels, this high- capacity enzyme is likely to be sufficient even in infants. Plasma samples were phenotyped for paraoxonase status, and frequencies were 0.5, 0.4, and 0.1 for QQ, QR, and RR phenotypes, respectively. These results will be integrated into a physiologically based pharmacokinetic and pharmacodynamic model for CPF and, once integrated, will be useful for assessing biological response to CPF exposures across life stages.
Collapse
Affiliation(s)
- Jordan Ned Smith
- Battelle, Pacific Northwest Division, Richland, Washington, USA.
| | | | | | | |
Collapse
|
46
|
Human variation in CYP-specific chlorpyrifos metabolism. Toxicology 2010; 276:184-91. [DOI: 10.1016/j.tox.2010.08.005] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Revised: 08/04/2010] [Accepted: 08/05/2010] [Indexed: 11/21/2022]
|
47
|
Li B, Ricordel I, Schopfer LM, Baud F, Mégarbane B, Nachon F, Masson P, Lockridge O. Detection of adduct on tyrosine 411 of albumin in humans poisoned by dichlorvos. Toxicol Sci 2010; 116:23-31. [PMID: 20395308 DOI: 10.1093/toxsci/kfq117] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Studies in mice and guinea pigs have shown that albumin is a new biomarker of organophosphorus toxicant (OP) and nerve agent exposure. Our goal was to determine whether OP-labeled albumin could be detected in the blood of humans exposed to OP. Blood from four OP-exposed patients was prepared for mass spectrometry analysis by digesting 0.010 ml of serum with pepsin and purifying the labeled albumin peptide by offline high performance liquid chromatography. Dimethoxyphosphate-labeled tyrosine 411 was identified in albumin peptides VRY(411)TKKVPQVSTPTL and LVRY(411)TKKVPQVSTPTL from two patients who had attempted suicide with dichlorvos. The butyrylcholinesterase activity in these serum samples was inhibited 80%. A third patient whose serum BChE activity was inhibited 8% by accidental inhalation of dichlorvos had undetectable levels of adduct on albumin. A fourth patient whose BChE activity was inhibited 60% by exposure to chlorpyrifos had no detectable adduct on albumin. This is the first report to demonstrate the presence of OP-labeled albumin in human patients. It is concluded that tyrosine 411 of human albumin is covalently modified in the serum of humans poisoned by dichlorvos and that the modification is detectable by mass spectrometry. The special reactivity of tyrosine 411 with OP suggests that other proteins may also be modified on tyrosine. Identification of other OP-modified proteins may lead to an understanding of neurotoxic symptoms that appear long after the initial OP exposure.
Collapse
Affiliation(s)
- Bin Li
- Eppley Institute, University of Nebraska Medical Center, Omaha, Nebraska 68198-5950, USA
| | | | | | | | | | | | | | | |
Collapse
|
48
|
Povey AC. Gene-environmental interactions and organophosphate toxicity. Toxicology 2010; 278:294-304. [PMID: 20156521 DOI: 10.1016/j.tox.2010.02.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2009] [Revised: 12/19/2009] [Accepted: 02/08/2010] [Indexed: 12/12/2022]
Abstract
Organophosphates (OPs) are an important class of insecticides that in the UK have been widely used for treating sheep for ectoparasites as well as in other sectors of the farming industry. Health problems associated with acute OP toxicity are well defined but, ill-health induced by chronic exposures to OPs remains controversial. A substantial number of sheep farmers complain of chronic ill-health which they attribute to repeated exposure to OPs. If OPs were associated with chronic ill-health then individuals with specific defects in OP metabolism might be expected to be at greater risk of ill-health following exposure. To examine such a hypothesis, the characterisation of both OP exposure and those pathways which lead to the formation and removal of the active OP metabolites becomes important. A wide range of OPs have previously been used to treat sheep but currently the only OP licenced for treating sheep is diazinon. Immediately after treatment, farmers' urines contain detectable levels of OP metabolites but few farmers have a significant decrease in plasma cholinesterase activity. Diazinon, like chlorpyrifos, is an organothiophosphate which is metabolised, particularly by cytochrome p450s, to the corresponding active oxon form. CYP metabolism also leads to the inactivation of the parent compound and the relative balance of inactivation and activation can depend upon the specific OP and the CYP isoform. OP oxons are inactivated by serum paraoxonase (PON1) and mice lacking PON1 activity are susceptible to oxon and parent OP induced toxicity. PON1 polymorphisms at positions 192 (R form with arginine at 192 and Q with glutamine) and 55 (L form with a leucine and a M form with methionine) influence paroxonase activity. The effect of the Q192R polymorphism is substrate specific with reports indicating that diazoxon is metabolised less by the R isoform. In a study of sheep farmers within the UK, the R allele was associated with an increased risk of self-reported chronic ill-health, a result consistent with the hypothesis that this ill-health may have been caused by OPs. Studies in other populations exposed to pesticides also show associations between ill-health and PON1 Q192R polymorphisms but not consistently so. This is not surprisingly given that exposure is often poorly characterised. In vivo models also suggest that PON1 genotypes may have little influence on susceptibility at low doses of the parent OP. Hence further work is required not only to better characterise OP exposure in humans populations but also to identify those populations susceptible to OP toxicity.
Collapse
Affiliation(s)
- Andrew C Povey
- Centre for Occupational and Environmental Health, School of Community-Based Medicine, Faculty of Medical and Human Sciences, University of Manchester, Ellen Wilkinson Building, Devas Street, Manchester M139PT, United Kingdom.
| |
Collapse
|
49
|
Jiang W, Duysen EG, Hansen H, Shlyakhtenko L, Schopfer LM, Lockridge O. Mice treated with chlorpyrifos or chlorpyrifos oxon have organophosphorylated tubulin in the brain and disrupted microtubule structures, suggesting a role for tubulin in neurotoxicity associated with exposure to organophosphorus agents. Toxicol Sci 2010; 115:183-93. [PMID: 20142434 DOI: 10.1093/toxsci/kfq032] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Exposure to organophosphorus (OP) agents can lead to learning and memory deficits. Disruption of axonal transport has been proposed as a possible explanation. Microtubules are an essential component of axonal transport. In vitro studies have demonstrated that OP agents react with tubulin and disrupt the structure of microtubules. Our goal was to determine whether in vivo exposure affects microtubule structure. One group of mice was treated daily for 14 days with a dose of chlorpyrifos that did not significantly inhibit acetylcholinesterase. Beta-tubulin from the brains of these mice was diethoxyphosphorylated on tyrosine 281 in peptide GSQQY(281)RALTVPELTQQMFDSK. A second group of mice was treated with a single sublethal dose of chlorpyrifos oxon (CPO). Microtubules and cosedimenting proteins from the brains of these mice were visualized by atomic force microscopy nanoimaging and by Coomassie blue staining of polyacrylamide gel electrophoresis bands. Proteins in gel slices were identified by mass spectrometry. Nanoimaging showed that microtubules from control mice were decorated with many proteins, whereas microtubules from CPO-treated mice had fewer associated proteins, a result confirmed by mass spectrometry of proteins extracted from gel slices. The dimensions of microtubules from CPO-treated mice (height 8.7 +/- 3.1 nm and width 36.5 +/- 15.5 nm) were about 60% of those from control mice (height 13.6 +/- 3.6 nm and width 64.8 +/- 15.9 nm). A third group of mice was treated with six sublethal doses of CPO over 50.15 h. Mass spectrometry identified diethoxyphosphorylated serine 338 in peptide NS(338)NFVEWIPNNVK of beta-tubulin. In conclusion, microtubules from mice exposed to chlorpyrifos or to CPO have covalently modified amino acids and abnormal structure, suggesting disruption of microtubule function. Covalent binding of CPO to tubulin and to tubulin-associated proteins is a potential mechanism of neurotoxicity.
Collapse
Affiliation(s)
- Wei Jiang
- Eppley Institute, University of Nebraska Medical Center, Omaha, Nebraska 68198-5950, USA
| | | | | | | | | | | |
Collapse
|
50
|
Asha S, Vidyavathi M. Role of Human Liver Microsomes in In Vitro Metabolism of Drugs—A Review. Appl Biochem Biotechnol 2009; 160:1699-722. [DOI: 10.1007/s12010-009-8689-6] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2009] [Accepted: 06/05/2009] [Indexed: 02/04/2023]
|