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Fernandez-Abascal J, Ripullone M, Valeri A, Leone C, Valoti M. β-Naphtoflavone and Ethanol Induce Cytochrome P450 and Protect towards MPP⁺ Toxicity in Human Neuroblastoma SH-SY5Y Cells. Int J Mol Sci 2018; 19:ijms19113369. [PMID: 30373287 PMCID: PMC6274691 DOI: 10.3390/ijms19113369] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 10/26/2018] [Accepted: 10/26/2018] [Indexed: 12/13/2022] Open
Abstract
Cytochrome P450 (CYP) isozymes vary their expression depending on the brain area, the cell type, and the presence of drugs. Some isoforms are involved in detoxification and/or toxic activation of xenobiotics in central nervous system. However, their role in brain metabolism and neurodegeneration is still a subject of debate. We have studied the inducibility of CYP isozymes in human neuroblastoma SH-SY5Y cells, treated with β-naphtoflavone (β-NF) or ethanol (EtOH) as inducers, by qRT-PCR, Western blot (WB), and metabolic activity assays. Immunohistochemistry was used to localize the isoforms in mitochondria and/or endoplasmic reticulum (ER). Tetrazolium (MTT) assay was performed to study the role of CYPs during methylphenyl pyridine (MPP+) exposure. EtOH increased mRNA and protein levels of CYP2D6 by 73% and 60% respectively. Both β-NF and EtOH increased CYP2E1 mRNA (4- and 1.4-fold, respectively) and protein levels (64% both). The 7-ethoxycoumarin O-deethylation and dextromethorphan O-demethylation was greater in treatment samples than in controls. Furthermore, both treatments increased by 22% and 18%, respectively, the cell viability in MPP+-treated cells. Finally, CYP2D6 localized at mitochondria and ER. These data indicate that CYP is inducible in SH-SY5Y cells and underline this in vitro system for studying the role of CYPs in neurodegeneration.
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Affiliation(s)
- Jesus Fernandez-Abascal
- Dipartimento di Scienze della Vita, Università di Siena, Via Aldo Moro 2, 53100 Siena, Italy.
| | - Mariantonia Ripullone
- Dipartimento di Scienze della Vita, Università di Siena, Via Aldo Moro 2, 53100 Siena, Italy.
| | - Aurora Valeri
- Molecular Horizon srl, Via Montelino 32, Bettona, 06084 Perugia, Italy.
| | - Cosima Leone
- Dipartimento di Scienze della Vita, Università di Siena, Via Aldo Moro 2, 53100 Siena, Italy.
| | - Massimo Valoti
- Dipartimento di Scienze della Vita, Università di Siena, Via Aldo Moro 2, 53100 Siena, Italy.
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Heidari R, Jamshidzadeh A, Keshavarz N, Azarpira N. Mitigation of Methimazole-Induced Hepatic Injury by Taurine in Mice. Sci Pharm 2014; 83:143-58. [PMID: 26839807 PMCID: PMC4727863 DOI: 10.3797/scipharm.1408-04] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 09/30/2014] [Indexed: 12/18/2022] Open
Abstract
Methimazole is the most widely prescribed antithyroid medication in humans. However, hepatotoxicity is a deleterious adverse effect associated with methimazole administration. No specific protective agent has been developed against this complication yet. This study was designed to investigate the role of taurine as a hepatoprotective agent against methimazole-induced liver injury in mice. Different reactive metabolites were proposed to be responsible for methimazole hepatotoxicity. Hence, methimazole-induced liver injury was investigated in intact and/or enzyme-induced animals in the current investigation. Animals were treated with methimazole (200 mg/kg, by gavage), and hepatic injury induced by this drug was investigated in intact and/or enzyme-induced groups. Markers such as lipid peroxidation, hepatic glutathione content, alanine aminotransferase (ALT) and alkaline phosphatase (ALP) in plasma, and histopathological changes in the liver of animals were monitored after drug administration. Methimazole caused liver injury as revealed by increased plasma ALT. Furthermore, a significant amount of lipid peroxidation was detected in the drug-treated animals, and hepatic glutathione reservoirs were depleted. Methimazole-induced hepatotoxicity was more severe in enzyme-induced mice. The above-mentioned alterations in hepatotoxicity markers were endorsed by significant histopathological changes in the liver. Taurine administration (1 g/kg, i.p.) effectively alleviated methimazole-induced liver injury in both intact and/or enzyme-induced animals.
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Affiliation(s)
- Reza Heidari
- Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, 7146864685 Shiraz, Iran
| | - Akram Jamshidzadeh
- Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, 7146864685 Shiraz, Iran; Pharmacology and Toxicology Department, Shiraz University of Medical Sciences, 7146864685 Shiraz, Iran
| | - Nahid Keshavarz
- Pharmacology and Toxicology Department, Shiraz University of Medical Sciences, 7146864685 Shiraz, Iran
| | - Negar Azarpira
- Transplant Research Center, Shiraz University of Medical Sciences, 7146864685 Shiraz, Iran
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Heidari R, Babaei H, Roshangar L, Eghbal MA. Effects of Enzyme Induction and/or Glutathione Depletion on Methimazole-Induced Hepatotoxicity in Mice and the Protective Role of N-Acetylcysteine. Adv Pharm Bull 2013; 4:21-8. [PMID: 24409405 DOI: 10.5681/apb.2014.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2013] [Revised: 06/12/2013] [Accepted: 06/13/2013] [Indexed: 01/28/2023] Open
Abstract
PURPOSE Methimazole is the most convenient drug used in the management of hyperthyroid patients. However, associated with its clinical use is hepatotoxicity as a life threatening adverse effect. The exact mechanism of methimazole-induced hepatotoxicity is still far from clear and no protective agent has been developed for this toxicity. METHODS This study attempts to evaluate the hepatotoxicity induced by methimazole at different experimental conditions in a mice model. Methimazole-induced hepatotoxicity was investigated in different situations such as enzyme induced and/or glutathione depleted animals. RESULTS Methimazole (100 mg/kg, i.p) administration caused hepatotoxicity as revealed by increase in serum alanine aminotransferase (ALT) activity as well as pathological changes of the liver. Furthermore, a significant reduction in hepatic glutathione content and an elevation in lipid peroxidation were observed in methimazole-treated mice. Combined administration of L-buthionine sulfoximine (BSO), as a glutathione depletory agent, caused a dramatic change in methimazole-induced hepatotoxicity characterized by hepatic necrosis and a severe elevation of serum ALT activity. Enzyme induction using phenobarbital and/or β-naphtoflavone beforehand, deteriorated methimazole-induced hepatotoxicity in mice. N-acetyl cysteine (300 mg/kg, i.p) administration effectively alleviated hepatotoxic effects of methimazole in both glutathione-depleted and/or enzyme induced animals. CONCLUSION The severe hepatotoxic effects of methimazole in glutathione-depleted animals, reveals the crucial role of glutathione as a cellular defense mechanism against methimazole-induced hepatotoxicity. Furthermore, the more hepatotoxic properties of methimazole in enzyme-induced mice, indicates the role of reactive intermediates in the hepatotoxicity induced by this drug. The protective effects of N-acetylcysteine could be attributed to its radical/reactive metabolite scavenging, and/or antioxidant properties as well as glutathione replenishment activities.
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Affiliation(s)
- Reza Heidari
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran. ; Pharmacology and Toxicology Department, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Hossein Babaei
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran. ; Pharmacology and Toxicology Department, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Leila Roshangar
- Anatomical Sciences Department, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Ali Eghbal
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran. ; Pharmacology and Toxicology Department, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran
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Eghbal MA, Taziki S, Sattari MR. Mechanisms of Phenytoin-Induced Toxicity in Freshly Isolated Rat Hepatocytes and the Protective Effects of Taurine and/or Melatonin. J Biochem Mol Toxicol 2013; 28:111-8. [DOI: 10.1002/jbt.21542] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 10/15/2013] [Accepted: 11/01/2013] [Indexed: 02/06/2023]
Affiliation(s)
- Mohammad Ali Eghbal
- Drug Applied Research Center; Tabriz University of Medical Sciences; Tabriz Iran
- Biotechnology Research Center; Tabriz University of Medical Sciences; Tabriz Iran
- Pharmacology and Toxicology Department; School of Pharmacy, Tabriz University of Medical Sciences; Tabriz Iran
| | - Shohreh Taziki
- Biotechnology Research Center; Tabriz University of Medical Sciences; Tabriz Iran
- Pharmacology and Toxicology Department; School of Pharmacy, Tabriz University of Medical Sciences; Tabriz Iran
- Students’ Research Committee; Tabriz University of Medical Sciences; Tabriz Iran
| | - Mohammad Reza Sattari
- Drug Applied Research Center; Tabriz University of Medical Sciences; Tabriz Iran
- Pharmacology and Toxicology Department; School of Pharmacy, Tabriz University of Medical Sciences; Tabriz Iran
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5
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Shah A, Kumar S, Simon SD, Singh DP, Kumar A. HIV gp120- and methamphetamine-mediated oxidative stress induces astrocyte apoptosis via cytochrome P450 2E1. Cell Death Dis 2013; 4:e850. [PMID: 24113184 PMCID: PMC3824683 DOI: 10.1038/cddis.2013.374] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Revised: 08/05/2013] [Accepted: 08/20/2013] [Indexed: 11/09/2022]
Abstract
HIV-1 glycoprotein 120 (gp120) is known to cause neurotoxicity via several mechanisms including production of proinflammatory cytokines/chemokines and oxidative stress. Likewise, drug abuse is thought to have a direct impact on the pathology of HIV-associated neuroinflammation through the induction of proinflammatory cytokines/chemokines and oxidative stress. In the present study, we demonstrate that gp120 and methamphetamine (MA) causes apoptotic cell death by inducing oxidative stress through the cytochrome P450 (CYP) and NADPH oxidase (NOX) pathways. The results showed that both MA and gp120 induced reactive oxygen species (ROS) production in concentration- and time-dependent manners. The combination of gp120 and MA also induced CYP2E1 expression at both mRNA (1.7±0.2- and 2.8±0.3-fold in SVGA and primary astrocytes, respectively) and protein (1.3±0.1-fold in SVGA and 1.4±0.03-fold in primary astrocytes) levels, suggesting the involvement of CYP2E1 in ROS production. This was further confirmed by using a selective inhibitor of CYP2E1, diallylsulfide (DAS), and CYP2E1 knockdown using siRNA, which significantly reduced ROS production (30–60%). As the CYP pathway is known to be coupled with the NOX pathway, including Fenton–Weiss–Haber (FWH) reaction, we examined whether the NOX pathway is also involved in ROS production induced by either gp120 or MA. Our results showed that selective inhibitors of NOX, diphenyleneiodonium (DPI), and FWH reaction, deferoxamine (DFO), also significantly reduced ROS production. These findings were further confirmed using specific siRNAs against NOX2 and NOX4 (NADPH oxidase family). We then showed that gp120 and MA both induced apoptosis (caspase-3 activity and DNA lesion using TUNEL (terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling) assay) and cell death. Furthermore, we showed that DAS, DPI, and DFO completely abolished apoptosis and cell death, suggesting the involvement of CYP and NOX pathways in ROS-mediated apoptotic cell death. In conclusion, this is the first report on the involvement of CYP and NOX pathways in gp120/MA-induced oxidative stress and apoptotic cell death in astrocytes, which has clinical implications in neurodegenerative diseases, including neuroAIDS.
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Affiliation(s)
- A Shah
- Division of Pharmacology and Toxicology, School of Pharmacy, University of Missouri-Kansas City, Kansas City, MO, USA
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Bajpai P, Sangar MC, Singh S, Tang W, Bansal S, Chowdhury G, Cheng Q, Fang JK, Martin MV, Guengerich FP, Avadhani NG. Metabolism of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine by mitochondrion-targeted cytochrome P450 2D6: implications in Parkinson disease. J Biol Chem 2013; 288:4436-51. [PMID: 23258538 PMCID: PMC3567693 DOI: 10.1074/jbc.m112.402123] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Revised: 11/27/2012] [Indexed: 11/06/2022] Open
Abstract
1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is a neurotoxic side product formed in the chemical synthesis of desmethylprodine opioid analgesic, which induces Parkinson disease. Monoamine oxidase B, present in the mitochondrial outer membrane of glial cells, catalyzes the oxidation of MPTP to the toxic 1-methyl-4-phenylpyridinium ion (MPP(+)), which then targets the dopaminergic neurons causing neuronal death. Here, we demonstrate that mitochondrion-targeted human cytochrome P450 2D6 (CYP2D6), supported by mitochondrial adrenodoxin and adrenodoxin reductase, can efficiently catalyze the metabolism of MPTP to MPP(+), as shown with purified enzymes and also in cells expressing mitochondrial CYP2D6. Neuro-2A cells stably expressing predominantly mitochondrion-targeted CYP2D6 were more sensitive to MPTP-mediated mitochondrial respiratory dysfunction and complex I inhibition than cells expressing predominantly endoplasmic reticulum-targeted CYP2D6. Mitochondrial CYP2D6 expressing Neuro-2A cells produced higher levels of reactive oxygen species and showed abnormal mitochondrial structures. MPTP treatment also induced mitochondrial translocation of an autophagic marker, Parkin, and a mitochondrial fission marker, Drp1, in differentiated neurons expressing mitochondrial CYP2D6. MPTP-mediated toxicity in primary dopaminergic neurons was attenuated by CYP2D6 inhibitor, quinidine, and also partly by monoamine oxidase B inhibitors deprenyl and pargyline. These studies show for the first time that dopaminergic neurons expressing mitochondrial CYP2D6 are fully capable of activating the pro-neurotoxin MPTP and inducing neuronal damage, which is effectively prevented by the CYP2D6 inhibitor quinidine.
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Affiliation(s)
- Prachi Bajpai
- From the Department of Animal Biology and Marie Lowe Center for Comparative Oncology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6046 and
| | - Michelle C. Sangar
- From the Department of Animal Biology and Marie Lowe Center for Comparative Oncology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6046 and
| | - Shilpee Singh
- From the Department of Animal Biology and Marie Lowe Center for Comparative Oncology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6046 and
| | - Weigang Tang
- From the Department of Animal Biology and Marie Lowe Center for Comparative Oncology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6046 and
| | - Seema Bansal
- From the Department of Animal Biology and Marie Lowe Center for Comparative Oncology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6046 and
| | - Goutam Chowdhury
- the Department of Biochemistry and Center in Molecular Toxicology, School of Medicine, Vanderbilt University, Nashville, Tennessee 37232-0146
| | - Qian Cheng
- the Department of Biochemistry and Center in Molecular Toxicology, School of Medicine, Vanderbilt University, Nashville, Tennessee 37232-0146
| | - Ji-Kang Fang
- From the Department of Animal Biology and Marie Lowe Center for Comparative Oncology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6046 and
| | - Martha V. Martin
- the Department of Biochemistry and Center in Molecular Toxicology, School of Medicine, Vanderbilt University, Nashville, Tennessee 37232-0146
| | - F. Peter Guengerich
- the Department of Biochemistry and Center in Molecular Toxicology, School of Medicine, Vanderbilt University, Nashville, Tennessee 37232-0146
| | - Narayan G. Avadhani
- From the Department of Animal Biology and Marie Lowe Center for Comparative Oncology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6046 and
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7
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Abstract
Selegiline, the R-optical enantiomer of deprenyl (phenyl-isopropyl-methyl-propargylamine), was almost exclusively used MAO-B inhibitor during the past decades to treat Parkinson's disease. Oral treatment prolongs the need of levodopa administration. Selegiline is rapidly metabolized by the microsomal enzymes to amphetamine, methamphetamine, and desmethyl-deprenyl. In addition, the flavin-containing monooxigenase is synthesizing deprenyl-N-oxide. Selegiline in rather low concentrations (10⁻⁹-10⁻¹³ M), does not influence MAO-B, but it has an antiapoptotic activity in tissue culture. The neuroprotective effect of selegiline has a biphasic character. In higher concentrations than 10⁻⁷ M increases the rate of apoptosis (proapoptotic activity). The metabolites are also taking part in the complex pharmacological activity of selegiline. The simultaneous presence of the pro- and antiapoptotic effects of selegiline and its metabolites frequently hindered its clinical usage. During the past years rasagiline has been introduced to replace selegiline in clinical application. MAO-B inhibitors beside their effect on the enzyme MAO-B could hold different spectrum of pharmacological activities. Selegiline is administered orally and it possesses an intensive "first pass" metabolism. To circumvent the "first pass" metabolism, parenteral administration of the drug might lead to different distribution and pharmacological activity of selegiline.
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Affiliation(s)
- Kálmán Magyar
- Department of Pharmacodynamics, Semmelweis University, Budapest, Hungary
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8
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Unzeta M, Sanz E. Novel MAO-B inhibitors: potential therapeutic use of the selective MAO-B inhibitor PF9601N in Parkinson's disease. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2011; 100:217-36. [PMID: 21971010 DOI: 10.1016/b978-0-12-386467-3.00011-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Parkinson's disease (PD) is a neurodegenerative disease that is characterized by preferential loss of dopaminergic neurons in the substantia nigra pars compacta, leading to declining levels of dopamine in the striatum. In our search for compounds able not only to extend the effects of dopamine by preventing its degradation but also to halt or slow the neurodegenerative process, we designed, synthesized, and biologically tested a series of propargylamines for their potential use as therapeutic agents for PD. Among them, PF9601N, [N-(2-propynyl)-2-(5-benzyloxy-indolyl) methylamine], showed high potency and selectivity as a MAO-BI (monoamine oxidase type B inhibitor) and also demonstrated remarkable neuroprotective properties in several in vivo and cellular models of PD. In this chapter, we describe the preclinical evidence revealing the novel MAO-BI PF9601N as an interesting candidate for the treatment of PD.
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Affiliation(s)
- Mercedes Unzeta
- Institut de Neurociències and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Cerdanyola del Vallès (Barcelona), Spain
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9
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Abstract
Deprenyl has been discovered by Knoll and co-workers. The R-enantiomer of deprenyl (selegiline) is a selective and irreversible inhibitor of the B-isoform of monoamine oxidase (MAO-B) enzyme. Due to its dopamine potentiating and possible neuroprotective properties it has an established role in the treatment of parkinsonian patients. By inhibiting MAO-B enzyme, R-deprenyl decreases the formation of hydrogen peroxide, alleviating the oxidative stress also reduced by increased expression of antioxidant enzymes (superoxide dismutases and catalase) reported during chronic treatment. It was shown to prevent the detrimental effects of neurotoxins like MPTP and DSP-4. R-Deprenyl elicits neuroprotective and neuronal rescue activities in concentrations too low to inhibit MAO-B. It is extensively metabolized and some of the metabolites possess pharmacological activities, thus their contribution to neuroprotective properties was also suggested. The recently identified deprenyl-N-oxide is extensively studied in our laboratory. Effects other than neuroprotection, like influencing cell adhesion and proliferation cannot be neglected.
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Siu ECK, Tyndale RF. Selegiline is a mechanism-based inactivator of CYP2A6 inhibiting nicotine metabolism in humans and mice. J Pharmacol Exp Ther 2007; 324:992-9. [PMID: 18065502 DOI: 10.1124/jpet.107.133900] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Selegiline (l-deprenyl) is in clinical treatment trials as a potential smoking cessation drug. We investigated the affect of selegiline and its metabolites on nicotine metabolism. In mice, selegiline was a potent inhibitor of nicotine metabolism in hepatic microsomes and cDNA-expressed CYP2A5; the selegiline metabolites desmethylselegiline, l-methamphetamine, and l-amphetamine, also inhibited nicotine metabolism. Pretreatment with selegiline and desmethylselegiline increased inhibition (IC(50)) in microsomes by 3.3- and 6.1-fold, respectively. In mice in vivo, selegiline increased AUC (90.7 +/- 5.8 versus 57.4 +/- 5.3 ng/h/ml, p < 0.05), decreased clearance (4.6 +/- 0.4 versus 7.3 +/- 0.3 ml/min, p < 0.05), and increased elimination half-life (12.5 +/- 6.3 versus 6.6 +/- 1.4 min, p < 0.05) of nicotine. In vitro, selegiline was a potent inhibitor of human nicotine metabolism in hepatic microsomes and cDNA-expressed CYP2A6; desmethylselegiline and l-amphetamine also inhibited nicotine metabolism. Selegiline preincubation increased inhibition in microsomes (3.7-fold) and CYP2A6 (14.8-fold); the K(i) for CYP2A6 was 4.2 muM. Selegiline dose- and time-dependently inhibited nicotine metabolism by CYP2A6 (K(i) = 15.6 +/- 2.7 muM; k(inact) = 0.34 +/- 0.04 min(-1)), and the inhibition was irreversible in the presence of NADPH, indicating that it is a mechanism-based inhibitor of CYP2A6. Thus, inhibition of mouse nicotine metabolism by selegiline was competitive in vitro and significantly increased plasma nicotine in vivo. In humans, where selegiline is both a competitive and mechanism-based inhibitor, it is likely to have even greater effects on in vivo nicotine metabolism. Our findings suggest that an additional potential mechanism of selegiline in smoking cessation is through inhibition of nicotine metabolism.
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Affiliation(s)
- Eric C K Siu
- Department of Pharmacology, University of Toronto, 1 King's College Circle, Room 4326, Toronto, Ontario, Canada
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Magyar K, Pálfi M, Jenei V, Szöko E. Deprenyl: from chemical synthesis to neuroprotection. JOURNAL OF NEURAL TRANSMISSION. SUPPLEMENTUM 2006:143-56. [PMID: 17447425 DOI: 10.1007/978-3-211-33328-0_16] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
During the last decades (-)-deprenyl has become the golden standard of MAO-B inhibitors. It possesses dopamine potentiating and antioxidant properties; however, its effects cannot be explained solely by the enzyme inhibitory action. (-)-Deprenyl prevents the toxicity of certain selective neurotoxins and recently it was demonstrated to increase cell-cell adhesion as well. The complexity of its pharmacological effects reflects the action of both the parent compound and the active metabolites. (-)-Deprenyl and related propargylamines (DRPs) show neuroprotective features in a variety of in vitro and in vivo models that is dependent on the propargyl moiety. The main presumptive targets to date include glyceraldehyde-3-phosphate dehydrogenase, poly(ADP-ribose) polymerase, some kinase cascades, as well as pro- and antiapoptotic proteins, beside the inhibition of MAO-B. The antiapoptotic activity of DRPs converges upon the maintenance of mitochondrial integrity, due to the initiation of a complex transcriptional program, the details of which are yet to be elucidated.
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Affiliation(s)
- K Magyar
- Department of Pharmacodynamics, Semmelweis University, Budapest, Hungary.
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Lévai F, Fejér E, Szeleczky G, Szabó A, Eros-Takácsy T, Hajdu F, Szebeni G, Szatmári I, Hermecz I. In vitro formation of selegiline-N-oxide as a metabolite of selegiline in human, hamster, mouse, rat, guinea-pig, rabbit and dog. Eur J Drug Metab Pharmacokinet 2004; 29:169-78. [PMID: 15537168 DOI: 10.1007/bf03190594] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
It is well established in the litrature, that selegiline is metabolised to its N-dealkylated metabolites, N-desmethylselegiline, methamphetamine and amphetamine. However, most studies on selegiline metabolism did not characterize the species differences in the formation of the metabolites. Therefore, in this study, we investigated the in vitro metabolism of selegiline in liver microsomes of different species. In addition, to the previously well-characterized metabolites, selegiline-N-oxide (selegiline-NO) was found to be formed as a metabolite of selegiline in rat liver microsomal preparation. The results of experiments with liver microsomes from other species indicated species differences in the rate and extent of formation of selegiline-NO. The dog and hamster liver microsomal preparations were the most active in terms of selegiline-NO production, whereas little selegiline was metabolized to its N-oxide in human liver microsomes. When selegiline-NO was incubated with rat liver microsomes, no metabolism occurred. When a short incubation time was applied in selegiline expriments no increase in the amount of selegiline-NO was detected. Accordingly, it was clear that selegiline was not metabolized to the N-dealkylated or N,N-bis-dealkylated compounds via selegiline-NO. Studies with different isoenzyme inhibitors indicated that the formation of selegiline-NO might be catalyzed at least partly by cytochrome P450 (CYP) 2D6 and CYP3A4. With the exception of hamster microsomes in the microsomal preparations in vitro, the formation of the R,S-stereoisomer of selegiline-NO was preferred.
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Affiliation(s)
- Ferenc Lévai
- R&D, Preclinical Development, Chinoin Co Ltd, a member of Sanofi-Synthelabo Group, Budapest, Hungary
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13
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Dragoni S, Bellik L, Frosini M, Matteucci G, Sgaragli G, Valoti M. Cytochrome P450-dependent metabolism of l-deprenyl in monkey (Cercopithecus aethiops) and C57BL/6 mouse brain microsomal preparations. J Neurochem 2003; 86:1174-80. [PMID: 12911625 DOI: 10.1046/j.1471-4159.2003.01927.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The aim of the present investigation was to characterize the cytochrome P450 (CYP)-dependent metabolism of l-deprenyl by brain microsomal preparations obtained from two different animal models that have been extensively used in Parkinson's disease studies, namely monkey (Cercopithecus aethiops) and C57BL/6 mouse. In monkey brain microsomal fractions, the apparent Km values for methamphetamine formation from l-deprenyl were 67.8 +/- 1.0 and 72.0 +/- 1.6 microm, in the cortex and striatum, respectively. Similarly, for nordeprenyl formation from l-deprenyl, Km values in cortex and striatum were 21.3 +/- 3.2 and 27.3 +/- 4.0 microm, respectively. Both metabolic pathways appear to be more efficient in the cortex than in the striatum as the Vmax for microsomal preparation was lower in the striatum for the formation of both metabolites. The formation rate of l-methamphetamine was up to one order of magnitude greater than that of nordeprenyl. Inhibition analysis of both pathways in monkey brain suggested that l-methamphetamine formation is catalysed by CYP2A and CYP3A, whereas only CYP3A appears to be involved in nordeprenyl formation. With microsomal preparations from whole brain of C57BL/6 mice, the only l-deprenyl metabolite that could be detected was methamphetamine and the Km and Vmax values were similar to those determined in monkey cortex (53.6 +/- 2.9 microm and 33.9 +/- 0.4 pmol/min/mg protein, respectively). 4-Methylpyrazole selectively inhibited methamphetamine formation, suggesting the involvement of CYP2E1. In conclusion, the present study indicates that l-deprenyl is effectively metabolised by CYP-dependent oxidases in the brain, giving rise mainly to the formation of methamphetamine, which has been suggested to play a role in the pharmacological effects of the parent drug. The results also demonstrate that there are differences between species in CYP-dependent metabolism of l-deprenyl.
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Affiliation(s)
- Stefania Dragoni
- Istituto di Scienze Farmacologiche, Centro Interdipartimentale di Ricerca sul Metabolismo dei Farmaci Neuropsicotropi, Università di Siena, Siena, Italy
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Dragoni S, Bellik L, Frosini M, Sgaragli G, Marini S, Gervasi PG, Valoti M. l-Deprenyl metabolism by the cytochrome P450 system in monkey (Cercopithecus aethiops) liver microsomes. Xenobiotica 2003; 33:181-95. [PMID: 12623760 DOI: 10.1080/0049825021000048827] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
1. The aim was to clarify the kinetic and cytochrome P450 (CYP) enzymes involved in l-deprenyl metabolism by liver microsomal preparations from African green monkeys, an animal model extensively used in the study of Parkinson's disease. 2. CYP levels and monoxygenase activities were similar to those observed in microsomes from other monkey strains. The enzyme kinetics of both l-methamphetamine and l-nordeprenyl formation were characterized by a high- and low-affinity component. For l-methamphetamine, the apparent K(m1) and K(m2) were 1.07 +/- 0.01 and 350 +/- 2.7 micro M, and V(max1) and V(max2) were 4.70 +/- 0.01 and 8.9 +/- 0.02 nmol min(-1) mg protein(-1), respectively. For l-nordeprenyl, K(m1) and K(m2) were 0.96 +/- 0.05 and 168 +/- 15 micro M, and V(max1) and V(max2) were 3.34 +/- 0.02 and 3.91 +/- 0.02 nmol min(-1) mg protein(-1), respectively The ratio V(max)/K(m) for both metabolites was 2 orders of magnitude higher for the low K(m) component than for the high K(m), suggesting that the former component is the major determinant of l-deprenyl N-dealkylation. At 15 micro M l-deprenyl, both ketoconazole and 8-methoxypsoralen significantly inhibited l-methamphetamine and l-nordeprenyl formation, indicating that CYP3A and CYP2A enzymes were involved in both reactions. At 500 micro M l-deprenyl, however, inhibition studies suggest the involvement of CYP1A and 2D enzymes. 3. The metabolism of l-deprenyl by monkey liver microsomes is very efficient, indicating that CYP-dependent metabolism is relevant and could contribute to neuroprotection in primate models of Parkinson's disease.
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Affiliation(s)
- S Dragoni
- Istituto di Scienze Farmacologiche, Centro Interdipartimentale di Ricerca sul Metabolismo dei Farmaci Neuropsicotropi, Università di Siena, Via Aldo Moro 2, I-53100 Siena, Italy
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Doran E, Whittington FW, Wood JD, McGivan JD. Cytochrome P450IIE1 (CYP2E1) is induced by skatole and this induction is blocked by androstenone in isolated pig hepatocytes. Chem Biol Interact 2002; 140:81-92. [PMID: 12044562 DOI: 10.1016/s0009-2797(02)00015-7] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Skatole, a derivative of tryptophan, is produced in the hind-gut of pigs and is metabolised via hepatic cytochrome P4502E1 (CYP2E1). Excessive accumulation of skatole together with androstenone, a metabolite of testosterone, in adipose tissue in some pigs is a major cause of 'boar taint' and is associated with defective expression of CYP2E1. This phenomenon is not understood because factors regulating CYP2E1 expression in pig liver have not yet been characterised. Therefore effects of skatole and androstenone on CYP2E1 expression were studied using isolated pig hepatocytes as a model system. Skatole induced CYP2E1 protein expression to the same degree as did acetone, a known CYP2E1 inducer. Induction by skatole was maximum between 20 and 28 h and a half-maximum effect was obtained at a skatole concentration of 0.2 mM. Induction of CYP2E1 by skatole was protein-synthesis dependent. Androstenone antagonised the effect of skatole on CYP2E1 expression but did not affect the CYP2E1 protein level when added alone. These results suggest that defective expression of CYP2E1 in some pigs is due to excessive concentrations of androstenone which prevent CYP2E1 induction by its substrate skatole. As a result, skatole metabolism is reduced and skatole is accumulated in adipose tissue.
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Affiliation(s)
- Elena Doran
- Department of Biochemistry, School of Medical Sciences, University of Bristol, University Walk, UK
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Kraemer T, Maurer HH. Toxicokinetics of amphetamines: metabolism and toxicokinetic data of designer drugs, amphetamine, methamphetamine, and their N-alkyl derivatives. Ther Drug Monit 2002; 24:277-89. [PMID: 11897973 DOI: 10.1097/00007691-200204000-00009] [Citation(s) in RCA: 164] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
This paper reviews the toxicokinetics of amphetamines. The designer drugs MDA (methylenedioxy-amphetamine, R,S-1-(3;,4;-methylenedioxyphenyl)2-propanamine), MDMA (R,S-methylenedioxymethamphetamine), and MDE (R,S-methylenedioxyethylamphetamine), as well as BDB (benzodioxolylbutanamine; R,S-1-(1;,3;-benzodioxol-5;-yl)-2-butanamine or R,S-1-(3;,4;-methylenedioxyphenyl)-2-butanamine) and MBDB (R,S-N-methyl-benzodioxolylbutanamine), were taken into consideration, as were the following N-alkylated amphetamine derivatives: amphetaminil, benzphetamine, clobenzorex, dimethylamphetamine, ethylamphetamine, famprofazone, fencamine, fenethylline, fenproporex, furfenorex, mefenorex, mesocarb, methamphetamine, prenylamine, and selegiline. English-language publications from 1995 to 2000 were reviewed. Papers describing identification of metabolites or cytochrome P450 isoenzyme-dependent metabolism and papers containing pharmacokinetic/toxicokinetic data were considered and summarized. The implications of toxicokinetics for toxicologic assessment or for interpretation in forensic cases are discussed.
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Affiliation(s)
- Thomas Kraemer
- Department of Experimental and Clinical Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, University of Saarland, D-66421 Homburg (Saar), Germany.
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