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Luethi D, Kolaczynska KE, Walter M, Suzuki M, Rice KC, Blough BE, Hoener MC, Baumann MH, Liechti ME. Metabolites of the ring-substituted stimulants MDMA, methylone and MDPV differentially affect human monoaminergic systems. J Psychopharmacol 2019; 33:831-841. [PMID: 31038382 PMCID: PMC8269116 DOI: 10.1177/0269881119844185] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Amphetamine analogs with a 3,4-methylenedioxy ring-substitution are among the most popular illicit drugs of abuse, exerting stimulant and entactogenic effects. Enzymatic N-demethylation or opening of the 3,4-methylenedioxy ring via O-demethylenation gives rise to metabolites that may be pharmacologically active. Indeed, previous studies in rats show that specific metabolites of 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxymethcathinone (methylone) and 3,4-methylenedioxypyrovalerone (MDPV) can interact with monoaminergic systems. AIM Interactions of metabolites of MDMA, methylone and MDPV with human monoaminergic systems were assessed. METHODS The ability of parent drugs and their metabolites to inhibit uptake of tritiated norepinephrine, dopamine and serotonin (5-HT) was assessed in human embryonic kidney 293 cells transfected with human monoamine transporters. Binding affinities and functional activity at monoamine transporters and various receptor subtypes were also determined. RESULTS MDMA and methylone displayed greater potency to inhibit norepinephrine uptake as compared to their effects on dopamine and 5-HT uptake. N-demethylation of MDMA failed to alter uptake inhibition profiles, whereas N-demethylation of methylone decreased overall transporter inhibition potencies. O-demethylenation of MDMA, methylone and MDPV resulted in catechol metabolites that maintained norepinephrine and dopamine uptake inhibition potencies, but markedly reduced activity at 5-HT uptake. O-methylation of the catechol metabolites significantly decreased norepinephrine uptake inhibition, resulting in metabolites lacking significant stimulant properties. CONCLUSIONS Several metabolites of MDMA, methylone and MDPV interact with human transporters and receptors at pharmacologically relevant concentrations. In particular, N-demethylated metabolites of MDMA and methylone circulate in unconjugated form and could contribute to the in vivo activity of the parent compounds in human users.
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Affiliation(s)
- Dino Luethi
- Division of Clinical Pharmacology and Toxicology, Department of Biomedicine, University Hospital Basel and University of Basel, Basel, Switzerland
| | - Karolina E. Kolaczynska
- Division of Clinical Pharmacology and Toxicology, Department of Biomedicine, University Hospital Basel and University of Basel, Basel, Switzerland
| | - Melanie Walter
- Division of Clinical Pharmacology and Toxicology, Department of Biomedicine, University Hospital Basel and University of Basel, Basel, Switzerland
| | - Masaki Suzuki
- Drug Design and Synthesis Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD, 20892, USA,On leave from the Medicinal Chemistry Research Laboratories, New Drug Research Division , Otsuka Pharmaceutical Co., Ltd., Tokushima, Japan
| | - Kenner C. Rice
- Drug Design and Synthesis Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Bruce E. Blough
- Center for Drug Discovery, Research Triangle Institute, Research Triangle Park, NC, 27709, USA
| | - Marius C. Hoener
- Neuroscience Research, pRED, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Michael H. Baumann
- Designer Drug Research Unit, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Matthias E. Liechti
- Division of Clinical Pharmacology and Toxicology, Department of Biomedicine, University Hospital Basel and University of Basel, Basel, Switzerland,Corresponding author: Prof. Dr. med. Matthias E. Liechti, Division of Clinical Pharmacology and Toxicology, University Hospital Basel, Schanzenstrasse 55, CH-4056 Basel, Switzerland. Tel: +41 61 328 68 68; Fax: +41 61 265 45 60;
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Kinetic mechanism of time-dependent inhibition of CYP2D6 by 3,4-methylenedioxymethamphetamine (MDMA): Functional heterogeneity of the enzyme and the reversibility of its inactivation. Biochem Pharmacol 2018; 156:86-98. [PMID: 30114388 DOI: 10.1016/j.bcp.2018.08.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Accepted: 08/08/2018] [Indexed: 12/16/2022]
Abstract
We investigate the mechanism of time-dependent inhibition (TDI) of human cytochrome P450 2D6 (CYP2D6) by 3,4-methylenedioxymethamphetamine (MDMA, ecstasy), one of the most widespread recreational drugs of abuse. In an effort to unravel the kinetic mechanism of the formation of metabolic inhibitory complex (MIC) of CYP2D6 with MDMA-derived carbene we carried out a series of spectrophotometric studies paralleled with registration of the kinetics of time-dependent inhibition (TDI) in CYP2D6-incorporated proteoliposomes. The high amplitude of spectral signal in this system allowed us to characterize the spectral properties of the formed MIC in details and obtain an accurate spectral signature of MIC formation. This information was then used in the studies with CYP2D6-containing microsomes of insect cells (CYP2D6 Supersomes™). Our results demonstrate that in both systems the formation of the ferrous carbene-derived MIC is relatively slow, reversible and is not associated with the accumulation of the ferric carbene intermediate, as takes place in the case of CYP3A4 and podophylotoxin. Furthermore, the limited amplitude of MIC formation suggests that only a fraction (∼50%) of spectrally detectable CYP2D6 in both proteoliposomes and Supersomes participates in the formation of MIC and is therefore involved in the MDMA metabolism. This observation reveals yet another example of a cytochrome P450 that exhibits persistent functional heterogeneity of its population in microsomal membranes. Our study provides a solid methodological background for further mechanistic studies of MIC formation in human liver microsomes and demonstrates that the potency and physiological relevance of MDMA-dependent TDI of CYP2D6 may be overestimated.
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Vevelstad M, Øiestad EL, Nerem E, Arnestad M, Bogen IL. Studies on Para-Methoxymethamphetamine (PMMA) Metabolite Pattern and Influence of CYP2D6 Genetics in Human Liver Microsomes and Authentic Samples from Fatal PMMA Intoxications. Drug Metab Dispos 2017; 45:1326-1335. [PMID: 28978661 DOI: 10.1124/dmd.117.077263] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 09/29/2017] [Indexed: 11/22/2022] Open
Abstract
Para-methoxymethamphetamine (PMMA) has caused numerous fatal poisonings worldwide and appears to be more toxic than other ring-substituted amphetamines. Systemic metabolism is suggested to be important for PMMA neurotoxicity, possibly through activation of minor catechol metabolites to neurotoxic conjugates. The aim of this study was to examine the metabolism of PMMA in humans; for this purpose, we used human liver microsomes (HLMs) and blood samples from three cases of fatal PMMA intoxication. We also examined the impact of CYP2D6 genetics on PMMA metabolism by using genotyped HLMs isolated from CYP2D6 poor, population-average, and ultrarapid metabolizers. In HLMs, PMMA was metabolized mainly to 4-hydroxymethamphetamine (OH-MA), whereas low concentrations of para-methoxyamphetamine (PMA), 4-hydroxyamphetamine (OH-A), dihydroxymethamphetamine (di-OH-MA), and oxilofrine were formed. The metabolite profile in the fatal PMMA intoxications were in accordance with the HLM study, with OH-MA and PMA being the major metabolites, whereas OH-A, oxilofrine, HM-MA and HM-A were detected in low concentrations. A significant influence of CYP2D6 genetics on PMMA metabolism in HLMs was found. The catechol metabolite di-OH-MA has previously been suggested to be involved in PMMA toxicity. Our studies show that the formation of di-OH-MA from PMMA was two to seven times lower than from an equimolar dose of the less toxic drug MDMA, and do not support the hypothesis of catechol metabolites as major determinants of fatal PMMA toxicity. The present study revealed the metabolite pattern of PMMA in humans and demonstrated a great impact of CYP2D6 genetics on human PMMA metabolism.
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Affiliation(s)
- Merete Vevelstad
- Department of Forensic Sciences, Oslo University Hospital (M.V., E.L.Ø., E.N., M.A., I.L.B.), and Institute of Clinical Medicine (M.V.), School of Pharmacy (E.L.Ø.), and Institute of Basic Medical Sciences (I.L.B.), University of Oslo, Oslo, Norway
| | - Elisabeth Leere Øiestad
- Department of Forensic Sciences, Oslo University Hospital (M.V., E.L.Ø., E.N., M.A., I.L.B.), and Institute of Clinical Medicine (M.V.), School of Pharmacy (E.L.Ø.), and Institute of Basic Medical Sciences (I.L.B.), University of Oslo, Oslo, Norway
| | - Elisabeth Nerem
- Department of Forensic Sciences, Oslo University Hospital (M.V., E.L.Ø., E.N., M.A., I.L.B.), and Institute of Clinical Medicine (M.V.), School of Pharmacy (E.L.Ø.), and Institute of Basic Medical Sciences (I.L.B.), University of Oslo, Oslo, Norway
| | - Marianne Arnestad
- Department of Forensic Sciences, Oslo University Hospital (M.V., E.L.Ø., E.N., M.A., I.L.B.), and Institute of Clinical Medicine (M.V.), School of Pharmacy (E.L.Ø.), and Institute of Basic Medical Sciences (I.L.B.), University of Oslo, Oslo, Norway
| | - Inger Lise Bogen
- Department of Forensic Sciences, Oslo University Hospital (M.V., E.L.Ø., E.N., M.A., I.L.B.), and Institute of Clinical Medicine (M.V.), School of Pharmacy (E.L.Ø.), and Institute of Basic Medical Sciences (I.L.B.), University of Oslo, Oslo, Norway
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Luethi D, Liechti ME, Krähenbühl S. Mechanisms of hepatocellular toxicity associated with new psychoactive synthetic cathinones. Toxicology 2017. [PMID: 28645576 DOI: 10.1016/j.tox.2017.06.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Synthetic cathinones are a new class of psychostimulant substances. Rarely, they can cause liver injury but associated mechanisms are not completely elucidated. In order to increase our knowledge about mechanisms of hepatotoxicity, we investigated the effect of five frequently used cathinones on two human cell lines. Bupropion was included as structurally related drug used therapeutically. In HepG2 cells, bupropion, MDPV, mephedrone and naphyrone depleted the cellular ATP content at lower concentrations (0.2-1mM) than cytotoxicity occurred (0.5-2mM), suggesting mitochondrial toxicity. In comparison, methedrone and methylone depleted the cellular ATP pool and induced cytotoxicity at similar concentrations (≥2mM). In HepaRG cells, cytotoxicity and ATP depletion could also be demonstrated, but cytochrome P450 induction did not increase the toxicity of the compounds investigated. The mitochondrial membrane potential was decreased in HepG2 cells by bupropion, MDPV and naphyrone, confirming mitochondrial toxicity. Bupropion, but not the other compounds, uncoupled oxidative phosphorylation. Bupropion, MDPV, mephedrone and naphyrone inhibited complex I and II of the electron transport chain, naphyrone also complex III. All four mitochondrial toxicants were associated with increased mitochondrial ROS and increased lactate production, which was accompanied by a decrease in the cellular total GSH pool for naphyrone and MDPV. In conclusion, bupropion, MDPV, mephedrone and naphyrone are mitochondrial toxicants impairing the function of the electron transport chain and depleting cellular ATP stores. Since liver injury is rare in users of these drugs, affected persons must have susceptibility factors rendering them more sensitive for these drugs.
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Affiliation(s)
- Dino Luethi
- Division of Clinical Pharmacology & Toxicology, University Hospital Basel, Basel, Switzerland; Department of Biomedicine, University of Basel, Basel, Switzerland; Swiss Centre of Applied Human Toxicology, Basel, Switzerland
| | - Matthias E Liechti
- Division of Clinical Pharmacology & Toxicology, University Hospital Basel, Basel, Switzerland; Department of Biomedicine, University of Basel, Basel, Switzerland; Swiss Centre of Applied Human Toxicology, Basel, Switzerland
| | - Stephan Krähenbühl
- Division of Clinical Pharmacology & Toxicology, University Hospital Basel, Basel, Switzerland; Department of Biomedicine, University of Basel, Basel, Switzerland; Swiss Centre of Applied Human Toxicology, Basel, Switzerland.
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Valente MJ, Araújo AM, Bastos MDL, Fernandes E, Carvalho F, Guedes de Pinho P, Carvalho M. Editor's Highlight: Characterization of Hepatotoxicity Mechanisms Triggered by Designer Cathinone Drugs (β-Keto Amphetamines). Toxicol Sci 2016; 153:89-102. [PMID: 27255387 DOI: 10.1093/toxsci/kfw105] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The use of cathinone designer drugs in recreational settings has been associated with severe toxic effects, including liver damage. The precise mechanisms by which cathinones induce hepatotoxicity and whether they act by common pathways remain to be elucidated. Herein, we assessed the toxicity of the cathinones methylone, pentedrone, 3,4-methylenedioxypyrovalerone (MDPV) and 4-methylethcathinone (4-MEC) in primary rat hepatocytes (PRH) and HepaRG cells, and compared with that of 3,4-methylenedioxymethamphetamine (MDMA). MDPV and pentedrone were significantly more toxic than MDMA, while methylone was the least cytotoxic compound. Importantly, PRH revealed to be the most sensitive experimental model and was thus used to explore the mechanisms underlying the observed toxicity. All drugs elicited the formation of reactive oxygen and nitrogen species (ROS and RNS), but more markedly for methylone, pentedrone and 4-MEC. GSH depletion was also a common effect at the highest concentration tested, whereas only MDPV and pentedrone caused a significant decrease in ATP levels. The antioxidants ascorbic acid or N-acetyl-L-cysteine partially attenuated the observed cell death. All cathinones triggered significant caspase activation and apoptosis, which was partially reversed by the caspase inhibitor Ac-LETD-CHO. In conclusion, the present data shows that (1) cathinones induce in vitro hepatotoxic effects that vary in magnitude among the different analogues, (2) oxidative stress and mitochondrial dysfunction play a role in cathinones-induced hepatic injury, and (3) apoptosis appears to be an important pathway of cell death elicited by these novel drugs.
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Affiliation(s)
- Maria João Valente
- *UCIBIO, REQUIMTE, Laboratory of Toxicology, Faculty of Pharmacy, University of Porto, Porto, Portugal;
| | - Ana Margarida Araújo
- *UCIBIO, REQUIMTE, Laboratory of Toxicology, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Maria de Lourdes Bastos
- *UCIBIO, REQUIMTE, Laboratory of Toxicology, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Eduarda Fernandes
- UCIBIO, REQUIMTE, Laboratory of Applied Chemistry, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Félix Carvalho
- *UCIBIO, REQUIMTE, Laboratory of Toxicology, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Paula Guedes de Pinho
- *UCIBIO, REQUIMTE, Laboratory of Toxicology, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Márcia Carvalho
- *UCIBIO, REQUIMTE, Laboratory of Toxicology, Faculty of Pharmacy, University of Porto, Porto, Portugal; FP-ENAS, CEBIMED, Fundação Ensino e Cultura Fernando Pessoa, Porto, Portugal
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Haufroid V, Hantson P. CYP2D6 genetic polymorphisms and their relevance for poisoning due to amfetamines, opioid analgesics and antidepressants. Clin Toxicol (Phila) 2015; 53:501-10. [DOI: 10.3109/15563650.2015.1049355] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Abstract
Because of their strong similarities to humans across physiologic, developmental, behavioral, immunologic, and genetic levels, nonhuman primates are essential models for a wide spectrum of biomedical research. But unlike other animal models, nonhuman primates possess substantial outbred genetic variation, reducing statistical power and potentially confounding interpretation of results in research studies. Although unknown genetic variation is a hindrance in studies that allocate animals randomly, taking genetic variation into account in study design affords an opportunity to transform the way that nonhuman primates are used in biomedical research. New understandings of how the function of individual genes in rhesus macaques mimics that seen in humans are greatly advancing the rhesus macaques utility as research models, but epistatic interaction, epigenetic regulatory mechanisms, and the intricacies of gene networks limit model development. We are now entering a new era of nonhuman primate research, brought on by the proliferation and rapid expansion of genomic data. Already the cost of a rhesus macaque genome is dwarfed by its purchase and husbandry costs, and complete genomic datasets will inevitably encompass each rhesus macaque used in biomedical research. Advancing this outcome is paramount. It represents an opportunity to transform the way animals are assigned and used in biomedical research and to develop new models of human disease. The genetic and genomic revolution brings with it a paradigm shift for nonhuman primates and new mandates on how nonhuman primates are used in biomedical research.
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Methylenedioxy designer drugs: Mass spectrometric characterization of their glutathione conjugates by means of liquid chromatography-high-resolution mass spectrometry/mass spectrometry and studies on their glutathionyl transferase inhibition potency. Anal Chim Acta 2014; 822:37-50. [DOI: 10.1016/j.aca.2014.03.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Revised: 03/07/2014] [Accepted: 03/16/2014] [Indexed: 01/09/2023]
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Herndon JM, Cholanians AB, Lizarraga LE, Lau SS, Monks TJ. Catechol-o-methyltransferase and 3,4-({+/-})-methylenedioxymethamphetamine toxicity. Toxicol Sci 2014; 139:162-73. [PMID: 24591155 DOI: 10.1093/toxsci/kfu035] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Metabolism of 3,4-(±)-methylenedioxymethamphetamine (MDMA) is necessary to elicit its neurotoxic effects. Perturbations in phase I and phase II hepatic enzymes can alter the neurotoxic profile of systemically administered MDMA. In particular, catechol-O-methyltransferase (COMT) plays a critical role in determining the fraction of MDMA that is converted to potentially neurotoxic metabolites. Thus, cytochrome P450 mediated demethylenation of MDMA, or its N-demethylated metabolite, 3,4-(±)-methylenedioxyamphetamine, give rise to the catechols, N-methyl-α-methyldopamine and α-methyldopamine, respectively. Methylation of these catechols by COMT limits their oxidation and conjugation to glutathione, a process that ultimately gives rise to neurotoxic metabolites. We therefore determined the effects of modulating COMT, a critical enzyme involved in determining the fraction of MDMA that is converted to potentially neurotoxic metabolites, on MDMA-induced toxicity. Pharmacological inhibition of COMT in the rat potentiated MDMA-induced serotonin deficits and exacerbated the acute MDMA-induced hyperthermic response. Using a genetic mouse model of COMT deficiency, in which mice lack a functional COMT gene, such mice displayed greater reductions in dopamine concentrations relative to their wild-type (WT) counterparts. Neither WT nor COMT deficient mice were susceptible to MDMA-induced decreases in serotonin concentrations. Interestingly, mice devoid of COMT were far more susceptible to the acute hyperthermic effects of MDMA, exhibiting greater increases in body temperature that ultimately resulted in death. Our findings support the view that COMT plays a pivotal role in determining the toxic response to MDMA.
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Affiliation(s)
- Joseph M Herndon
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, Arizona 85721
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Mixtures of 3,4-methylenedioxymethamphetamine (ecstasy) and its major human metabolites act additively to induce significant toxicity to liver cells when combined at low, non-cytotoxic concentrations. J Appl Toxicol 2013; 34:618-27. [PMID: 23670916 DOI: 10.1002/jat.2885] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Revised: 03/08/2013] [Accepted: 03/18/2013] [Indexed: 11/07/2022]
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Goodwin AK, Mueller M, Shell CD, Ricaurte GA, Ator NA. Behavioral effects and pharmacokinetics of (±)-3,4-methylenedioxymethamphetamine (MDMA, Ecstasy) after intragastric administration to baboons. J Pharmacol Exp Ther 2013; 345:342-53. [PMID: 23516331 DOI: 10.1124/jpet.113.203729] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
(±)-3,4-Methylenedioxymethamphetamine (MDMA, "Ecstasy") is a popular drug of abuse. We aimed to characterize the behavioral effects of intragastric MDMA in a species closely related to humans and to relate behavioral effects to plasma MDMA and metabolite concentrations. Single doses of MDMA (0.32-7.8 mg/kg) were administered via an intragastric catheter to adult male baboons (N = 4). Effects of MDMA on food-maintained responding were assessed over a 20-hour period, whereas untrained behaviors and fine-motor coordination were characterized every 30 minutes until 3 hours postadministration. Levels of MDMA and metabolites in plasma were measured in the same animals (n = 3) after dosing on a separate occasion. MDMA decreased food-maintained responding over the 20-hour period, and systematic behavioral observations revealed increased frequency of bruxism as the dose of MDMA was increased. Drug blood level determinations showed no MDMA after the lower doses of MDMA tested (0.32-1.0 mg/kg) and modest levels after higher MDMA doses (3.2-7.8 mg/kg). High levels of 3,4-dihydroxymethamphetamine (HHMA) were detected after all doses of MDMA, suggesting extensive first-pass metabolism of MDMA in the baboon. The present results demonstrate that MDMA administered via an intragastric catheter produced behavioral effects that have also been reported in humans. Similar to humans, blood levels of MDMA after oral administration may not be predictive of the behavioral effects of MDMA. Metabolites, particularly HHMA, may play a significant role in the behavioral effects of MDMA.
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Affiliation(s)
- Amy K Goodwin
- Division of Behavioral Biology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21224-6823, USA
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Carvalho M, Carmo H, Costa VM, Capela JP, Pontes H, Remião F, Carvalho F, Bastos MDL. Toxicity of amphetamines: an update. Arch Toxicol 2012; 86:1167-231. [PMID: 22392347 DOI: 10.1007/s00204-012-0815-5] [Citation(s) in RCA: 259] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2012] [Accepted: 02/02/2012] [Indexed: 01/06/2023]
Abstract
Amphetamines represent a class of psychotropic compounds, widely abused for their stimulant, euphoric, anorectic, and, in some cases, emphathogenic, entactogenic, and hallucinogenic properties. These compounds derive from the β-phenylethylamine core structure and are kinetically and dynamically characterized by easily crossing the blood-brain barrier, to resist brain biotransformation and to release monoamine neurotransmitters from nerve endings. Although amphetamines are widely acknowledged as synthetic drugs, of which amphetamine, methamphetamine, and 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) are well-known examples, humans have used natural amphetamines for several millenniums, through the consumption of amphetamines produced in plants, namely cathinone (khat), obtained from the plant Catha edulis and ephedrine, obtained from various plants in the genus Ephedra. More recently, a wave of new amphetamines has emerged in the market, mainly constituted of cathinone derivatives, including mephedrone, methylone, methedrone, and buthylone, among others. Although intoxications by amphetamines continue to be common causes of emergency department and hospital admissions, it is frequent to find the sophism that amphetamine derivatives, namely those appearing more recently, are relatively safe. However, human intoxications by these drugs are increasingly being reported, with similar patterns compared to those previously seen with classical amphetamines. That is not surprising, considering the similar structures and mechanisms of action among the different amphetamines, conferring similar toxicokinetic and toxicological profiles to these compounds. The aim of the present review is to give an insight into the pharmacokinetics, general mechanisms of biological and toxicological actions, and the main target organs for the toxicity of amphetamines. Although there is still scarce knowledge from novel amphetamines to draw mechanistic insights, the long-studied classical amphetamines-amphetamine itself, as well as methamphetamine and MDMA, provide plenty of data that may be useful to predict toxicological outcome to improvident abusers and are for that reason the main focus of this review.
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Affiliation(s)
- Márcia Carvalho
- REQUIMTE, Laboratory of Toxicology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Portugal
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Yubero-Lahoz S, Pardo R, Farre M, Mathuna BÓ, Torrens M, Mustata C, Perez-Mañá C, Langohr K, Carbó ML, de la Torre R. Changes in CYP1A2 Activity in Humans after 3,4-Methylenedioxymethamphetamine (MDMA, Ecstasy) Administration Using Caffeine as a Probe Drug. Drug Metab Pharmacokinet 2012; 27:605-13. [DOI: 10.2133/dmpk.dmpk-12-rg-032] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Antolino-Lobo I, Meulenbelt J, van den Berg M, van Duursen MB. A mechanistic insight into 3,4-methylenedioxymethamphetamine (“ecstasy”)-mediated hepatotoxicity. Vet Q 2011; 31:193-205. [DOI: 10.1080/01652176.2011.642534] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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Antolino-Lobo I, Meulenbelt J, Molendijk J, Nijmeijer SM, Scherpenisse P, van den Berg M, van Duursen MB. Induction of glutathione synthesis and conjugation by 3,4-methylenedioxymethamphetamine (MDMA) and 3,4-dihydroxymethamphetamine (HHMA) in human and rat liver cells, including the protective role of some antioxidants. Toxicology 2011; 289:175-84. [DOI: 10.1016/j.tox.2011.08.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2011] [Revised: 08/09/2011] [Accepted: 08/10/2011] [Indexed: 12/15/2022]
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3,4-Methylenedioxymethamphetamine (MDMA) interacts with therapeutic drugs on CYP3A by inhibition of pregnane X receptor (PXR) activation and catalytic enzyme inhibition. Toxicol Lett 2011; 203:82-91. [DOI: 10.1016/j.toxlet.2011.03.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Revised: 03/03/2011] [Accepted: 03/04/2011] [Indexed: 01/16/2023]
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Golka K, Selinski S, Lehmann ML, Blaszkewicz M, Marchan R, Ickstadt K, Schwender H, Bolt HM, Hengstler JG. Genetic variants in urinary bladder cancer: collective power of the “wimp SNPs”. Arch Toxicol 2011; 85:539-54. [DOI: 10.1007/s00204-011-0676-3] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Accepted: 02/09/2011] [Indexed: 02/07/2023]
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Johansson I, Ingelman-Sundberg M. Genetic polymorphism and toxicology--with emphasis on cytochrome p450. Toxicol Sci 2010; 120:1-13. [PMID: 21149643 DOI: 10.1093/toxsci/kfq374] [Citation(s) in RCA: 177] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Individual susceptibility to environmental, chemical, and drug toxicity is to some extent determined by polymorphism in drug-metabolizing enzymes, in particular the cytochromes P450 (CYPs). This polymorphism is in particular translated into risk differences concerning drugs metabolized by the highly polymorphic enzymes CYP2C9, CYP2C19, and CYP2D6, whereas CYP enzymes active in procarcinogen activation are relatively well conserved without important functional polymorphisms. Examples of drug toxicities that can be predicted by P450 polymorphism include those exerted by codeine, tramadol, warfarin, acenocoumarol, and clopidogrel. The polymorphic CYP2A6 has a role in nicotine metabolism and smoking behavior. Besides this genetic variation, genome-wide association studies now allow for the identification of an increasing number of predictive genetic biomarkers among, e.g., human leukocyte antigens and to some extent drug transporters that provide useful information regarding the choice of the drug and drug dosage in order to avoid toxicity. The translation of this information into the clinical practice has been slow; however, an increasing number of pharmacogenomic drug labels are assigned, where the predictive genotyping before drug treatment can be mandatory, recommended, or only for informational purposes. In this review, we provide an update of the field with emphasis on CYP polymorphism.
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Affiliation(s)
- Inger Johansson
- Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, 171 77 Stockholm, Sweden
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Cytochrome P450-2D6 extensive metabolizers are more vulnerable to methamphetamine-associated neurocognitive impairment: preliminary findings. J Int Neuropsychol Soc 2010; 16:890-901. [PMID: 20727252 PMCID: PMC3543816 DOI: 10.1017/s1355617710000779] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
While neuropsychological deficits are evident among methamphetamine (meth) addicts, they are often unrelated to meth exposure parameters such as lifetime consumption and length of abstinence. The notion that some meth users develop neuropsychological impairments while others with similar drug exposure do not, suggests that there may be individual differences in vulnerability to the neurotoxic effects of meth. One source of differential vulnerability could come from genotypic variability in metabolic clearance of meth, dependent on the activity of cytochrome P450-2D6 (CYP2D6). We compared neuropsychological performance in 52 individuals with a history of meth dependence according with their CYP2D6 phenotype. All were free of HIV or hepatitis C infection and did not meet dependence criteria for other substances. Extensive metabolizers showed worse overall neuropsychological performance and were three times as likely to be cognitively impaired as intermediate/poor metabolizers. Groups did not differ in their demographic or meth use characteristics, nor did they evidence differences in mood disorder or other substance use. This preliminary study is the first to suggest that efficient meth metabolism is associated with worse neurocognitive outcomes in humans, and implicates the products of oxidative metabolism of meth as a possible source of brain injury.
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Antolino-Lobo I, Meulenbelt J, Nijmeijer SM, Scherpenisse P, van den Berg M, van Duursen MBM. Differential roles of phase I and phase II enzymes in 3,4-methylendioxymethamphetamine-induced cytotoxicity. Drug Metab Dispos 2010; 38:1105-12. [PMID: 20388857 DOI: 10.1124/dmd.110.032359] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Metabolism plays an important role in the toxic effects caused by 3,4-methylenedioxymethamphetamine (MDMA). Most research has focused on the involvement of CYP2D6 enzyme in MDMA bioactivation, and less is known about the contribution of other cytochrome P450 (P450) and phase II metabolism. In this study, we researched the differential roles of phase I P450 enzymes CYP1A2, CYP3A4, and CYP2D6 and phase II enzymes glutathione S-transferase (GST) and catechol-O-methyltransferase (COMT) on the toxic potential of MDMA. MDMA acts as inhibitor of its own metabolism with a relative potency of inhibition of CYP2D>CYP3A>> CYP1A in rat liver microsomes and in human liver [immortalized human liver epithelial cells (THLE)] cells transfected with individual CYP1A2, CYP3A4, or CYP2D6. Cytotoxicity measurements [by 3,(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] in THLE cells showed that the inhibition of phase I enzymes CYP1A2 by alpha-naphthoflavone and CYP3A4 by troleandomycin does not affect MDMA-induced cytotoxicity. MDMA metabolism by CYP2D6 significantly increased cytotoxicity, which was counteracted by CYP2D6 inhibition by quinidine. Inhibition of COMT by 2'-fluoro-3,4-dihydroxy-5-nitrobenzophenone (Ro-41-0960) and GST by buthionine sulfoximine showed that COMT is mainly involved in detoxification of CYP2D6-formed MDMA metabolites, whereas glutathione (GSH) is mainly involved in detoxification of CYP3A4-formed MDMA metabolites. Liquid chromatography/tandem mass spectrometry analyses of MDMA-metabolites in the THLE cell culture media confirmed formation of the specific MDMA metabolites and corroborated the observed cytotoxicity. Our data suggest that CYP2D6 as well as CYP3A4 play an important role in MDMA bioactivation. In addition, further studies are needed to address the differential roles of CYP3A4 and GSH/GST in MDMA bioactivation and detoxification.
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Affiliation(s)
- Irene Antolino-Lobo
- Institute for Risk Assessment Sciences, Utrecht University, Utrecht, Netherlands.
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23
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Schober W, Pusch G, Oeder S, Reindl H, Behrendt H, Buters JT. Metabolic activation of phenanthrene by human and mouse cytochromes P450 and pharmacokinetics in CYP1A2 knockout mice. Chem Biol Interact 2010; 183:57-66. [DOI: 10.1016/j.cbi.2009.09.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2009] [Revised: 09/10/2009] [Accepted: 09/11/2009] [Indexed: 11/16/2022]
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Zhou SF, Liu JP, Chowbay B. Polymorphism of human cytochrome P450 enzymes and its clinical impact. Drug Metab Rev 2009; 41:89-295. [PMID: 19514967 DOI: 10.1080/03602530902843483] [Citation(s) in RCA: 502] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Pharmacogenetics is the study of how interindividual variations in the DNA sequence of specific genes affect drug response. This article highlights current pharmacogenetic knowledge on important human drug-metabolizing cytochrome P450s (CYPs) to understand the large interindividual variability in drug clearance and responses in clinical practice. The human CYP superfamily contains 57 functional genes and 58 pseudogenes, with members of the 1, 2, and 3 families playing an important role in the metabolism of therapeutic drugs, other xenobiotics, and some endogenous compounds. Polymorphisms in the CYP family may have had the most impact on the fate of therapeutic drugs. CYP2D6, 2C19, and 2C9 polymorphisms account for the most frequent variations in phase I metabolism of drugs, since almost 80% of drugs in use today are metabolized by these enzymes. Approximately 5-14% of Caucasians, 0-5% Africans, and 0-1% of Asians lack CYP2D6 activity, and these individuals are known as poor metabolizers. CYP2C9 is another clinically significant enzyme that demonstrates multiple genetic variants with a potentially functional impact on the efficacy and adverse effects of drugs that are mainly eliminated by this enzyme. Studies into the CYP2C9 polymorphism have highlighted the importance of the CYP2C9*2 and *3 alleles. Extensive polymorphism also occurs in other CYP genes, such as CYP1A1, 2A6, 2A13, 2C8, 3A4, and 3A5. Since several of these CYPs (e.g., CYP1A1 and 1A2) play a role in the bioactivation of many procarcinogens, polymorphisms of these enzymes may contribute to the variable susceptibility to carcinogenesis. The distribution of the common variant alleles of CYP genes varies among different ethnic populations. Pharmacogenetics has the potential to achieve optimal quality use of medicines, and to improve the efficacy and safety of both prospective and currently available drugs. Further studies are warranted to explore the gene-dose, gene-concentration, and gene-response relationships for these important drug-metabolizing CYPs.
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Affiliation(s)
- Shu-Feng Zhou
- School of Health Sciences, RMIT University, Bundoora, Victoria, Australia.
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25
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Capela JP, Carmo H, Remião F, Bastos ML, Meisel A, Carvalho F. Molecular and Cellular Mechanisms of Ecstasy-Induced Neurotoxicity: An Overview. Mol Neurobiol 2009; 39:210-71. [DOI: 10.1007/s12035-009-8064-1] [Citation(s) in RCA: 210] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2008] [Accepted: 02/27/2009] [Indexed: 11/29/2022]
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Metabolites of MDMA induce oxidative stress and contractile dysfunction in adult rat left ventricular myocytes. Cardiovasc Toxicol 2009; 9:30-8. [PMID: 19333788 DOI: 10.1007/s12012-009-9034-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2009] [Accepted: 03/18/2009] [Indexed: 10/20/2022]
Abstract
Repeated administration of 3,4-methylenedioxymethamphetamine (MDMA) (ecstasy) produces eccentric left ventricular (LV) dilation and diastolic dysfunction. While the mechanism(s) underlying this toxicity are unknown, oxidative stress plays an important role. MDMA is metabolized into redox cycling metabolites that produce superoxide. In this study, we demonstrated that metabolites of MDMA induce oxidative stress and contractile dysfunction in adult rat left ventricular myocytes. Metabolites of MDMA used in this study included alpha-methyl dopamine, N-methyl alpha-methyl dopamine and 2,5-bis(glutathion-S-yl)-alpha-MeDA. Dihydroethidium was used to detect drug-induced increases in reactive oxygen species (ROS) production in ventricular myocytes. Contractile function and changes in intracellular calcium transients were measured in paced (1 Hz), Fura-2 AM loaded, myocytes using the IonOptix system. Production of ROS in ventricular myocytes treated with MDMA was not different from control. In contrast, all three metabolites of MDMA exhibited time- and concentration-dependent increases in ROS that were prevented by N-acetyl-cysteine (NAC). The metabolites of MDMA, but not MDMA alone, significantly decreased contractility and impaired relaxation in myocytes stimulated at 1 Hz. These effects were prevented by NAC. Together, these data suggest that MDMA-induced oxidative stress in the left ventricle can be due, at least in part, to the metabolism of MDMA to redox active metabolites.
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Keyes KM, Martins SS, Hasin DS. Past 12-month and lifetime comorbidity and poly-drug use of ecstasy users among young adults in the United States: results from the National Epidemiologic Survey on Alcohol and Related Conditions. Drug Alcohol Depend 2008; 97:139-49. [PMID: 18524499 PMCID: PMC3771490 DOI: 10.1016/j.drugalcdep.2008.04.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2008] [Revised: 04/02/2008] [Accepted: 04/09/2008] [Indexed: 11/20/2022]
Abstract
BACKGROUND Ecstasy use is prevalent among young people and often co-occurs with other drug use, but little is known about the past 12-month and lifetime psychiatric comorbidity and specific additional drug abuse among young adult ecstasy users in the general population. To provide this information, we compared current ecstasy users to former users, other illicit drug users, and non-illicit drug users. METHOD Data were gathered in a face-to-face survey of the United States conducted in the 2001-2002 (NESARC). Participants were household and group quarters residents aged 18-29 years (n=8666). We measured current ecstasy use defined as any use in the past year; former ecstasy use as use prior to the past year only; other lifetime drug use included any drug other than ecstasy; lifetime non-illicit drug use as no illicit drug use. Associations were determined for nine other classes of illicit drugs, eight personality disorders, and seven mood and anxiety disorders. RESULTS Of current ecstasy users, 44% used >3 other classes of illicit drugs in the past year, compared to 1.6% of non-ecstasy drug users. Current ecstasy use was associated with current anxiety (OR=3.7), specifically panic disorder (OR=7.7) and specific phobia (OR=4.1), also alcohol abuse (OR=21.6) and dependence (OR=4.1) and any personality disorder (OR=5.1) compared to non-illicit drug users. CONCLUSIONS Results indicate important differences in comorbidities of current and former ecstasy users compared to other drug users and lifetime non-illicit drug users that may affect phenotype definitions and etiologic studies. Ecstasy use may represent a distinct population of drug users for which unique treatments may be necessary.
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Affiliation(s)
- Katherine M. Keyes
- New York State Psychiatric Institute, New York, NY 10032, United States
- Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY 10032, United States
| | - Silvia S. Martins
- Department of Mental Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, United States
| | - Deborah S. Hasin
- New York State Psychiatric Institute, New York, NY 10032, United States
- Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY 10032, United States
- Department of Psychiatry, College of Physicians and Surgeons, Columbia University, New York, NY 10032, United States
- Corresponding author at: Columbia University, New York State Psychiatric Institute, 1051 Riverside Drive #123, New York, NY 10032, United States. Tel.: +1 212 543 5035; fax: +1 212 543 5913
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Failure in drug development: the role of inhibition and induction of cytochrome P450 enzymes. Arch Toxicol 2008; 82:665-6. [DOI: 10.1007/s00204-008-0355-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Pontes H, Duarte JA, de Pinho PG, Soares ME, Fernandes E, Dinis-Oliveira RJ, Sousa C, Silva R, Carmo H, Casal S, Remião F, Carvalho F, Bastos ML. Chronic exposure to ethanol exacerbates MDMA-induced hyperthermia and exposes liver to severe MDMA-induced toxicity in CD1 mice. Toxicology 2008; 252:64-71. [PMID: 18761051 DOI: 10.1016/j.tox.2008.07.064] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2008] [Revised: 07/24/2008] [Accepted: 07/26/2008] [Indexed: 11/29/2022]
Abstract
3,4-Methylenedioxymethamphetamine (MDMA; ecstasy) is an amphetamine derivative drug with entactogenic, empathogenic and hallucinogenic properties, commonly consumed at rave parties in a polydrug abuse pattern, especially with cannabis, tobacco and ethanol. Since both MDMA and ethanol may cause deleterious effects to the liver, the evaluation of their putative hepatotoxic interaction is of great interest, especially considering that most of the MDMA users are regular ethanol consumers. Thus, the aim of the present study was to evaluate, in vivo, the acute hepatotoxic effects of MDMA (10mg/kg i.p.) in CD-1 mice previously exposed to 12% ethanol as drinking fluid (for 8 weeks). Body temperature was continuously measured for 12h after MDMA administration and, after 24h, hepatic damage was evaluated. The administration of MDMA to non pre-treated mice resulted in sustained hyperthermia, which was significantly increased in ethanol pre-exposed mice. A correspondent higher increase of hepatic heat shock transcription factor (HSF-1) activation was also observed in the latter group. Furthermore, MDMA administration resulted in liver damage as confirmed by histological analysis, slight decrease in liver weight and increased plasma transaminases levels. These hepatotoxic effects were also exacerbated when mice were pre-treated with ethanol. The activities of some antioxidant enzymes (such as SOD, GPx and Catalase) were modified by ethanol, MDMA and their joint action. The hepatotoxicity resulting from the simultaneous exposure to MDMA and ethanol was associated with a higher activation of NF-kappaB, indicating a pro-inflammatory effect in this organ. In conclusion, the obtained results strongly suggest that the consumption of ethanol increases the hyperthermic and hepatotoxic effects associated with MDMA abuse.
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Affiliation(s)
- Helena Pontes
- REQUIMTE, Toxicology Department, Faculty of Pharmacy, University of Porto, Rua Aníbal Cunha 164, 4099-030 Porto, Portugal.
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Plasma pharmacokinetics of 3,4-methylenedioxymethamphetamine after controlled oral administration to young adults. Ther Drug Monit 2008; 30:320-32. [PMID: 18520604 DOI: 10.1097/ftd.0b013e3181684fa0] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
This study examines the plasma pharmacokinetics of 3,4-methylenedioxymethamphetamine (MDMA) and metabolites 4-hydroxy-3-methoxymethamphetamine (HMMA), 3,4-methylenedioxyamphetamine (MDA), and 4-hydroxy-3-methoxyamphetamine (HMA) in young adults for up to 143 hours after drug administration. Seventeen female and male participants (black, white, and Hispanic) received placebo, low (1.0 mg/kg), and high (1.6 mg/kg) oral MDMA doses (comparable to recreational doses) in a double-blind, randomized, balanced, within-subject design while residing on a closed research unit. Doses were separated by 1 week or more. A fully validated two-dimensional gas chromatography/mass spectrometry method simultaneously quantified MDMA, HMMA, MDA, and HMA. Calibration curves were MDA, 1 to 100 ng/mL; HMA, 2.5 to 100 ng/mL; and MDMA and HMMA, 2.5 to 400 ng/mL. Mean +/- standard deviation maximum plasma concentrations (C(max)) of 162.9 +/- 39.8 and 171.9 +/- 79.5 ng/mL were observed for MDMA and HMMA, respectively, after low-dose MDMA. After the high dose, mean MDMA Cmax significantly increased to 291.8 +/- 76.5 ng/mL, whereas mean HMMA C(max) was unchanged at 173.5 +/- 66.3 ng/mL. High intersubject variability in C(max) was observed. Mean MDA C(max) were 8.4 +/- 2.1 (low) and 13.8 +/- 3.8 (high) ng/mL. HMA Cmax were 3.5 +/- 0.4 and 3.9 +/- 0.9 ng/mL after the low and high doses, respectively. AUC infinity displayed similar trends to C(max), demonstrating nonlinear pharmacokinetics. Times of last plasma detection were generally HMA < MDA < MDMA < HMMA. Mean half-lives (t1/2) of MDMA, MDA, and HMMA were approximately 7 to 8 hours, 10.5 to 12.5 hours, and 11.5 to 13.5 hours, respectively. HMA t1/2 showed high variability. Mean MDMA volume of distribution was constant for low and high doses; clearance was significantly higher after the low dose. This study presents MDMA plasma pharmacokinetic data for the first time from blacks and females as well as measurement of HMMA and HMA concentrations after low and high MDMA doses and more frequent and extended plasma sampling than in prior studies.
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Bolt HM, Hengstler JG. A new series of review articles on drug metabolizing enzymes: nomenclature of isoenzyme families, genetic organization, polymorphisms, substrate specificities, clinical relevance and role in carcinogenesis. Arch Toxicol 2008; 82:413-4. [DOI: 10.1007/s00204-008-0321-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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32
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Xenobiotic metabolizing enzymes in the central nervous system: Contribution of cytochrome P450 enzymes in normal and pathological human brain. Biochimie 2008; 90:426-36. [DOI: 10.1016/j.biochi.2007.10.007] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2007] [Accepted: 10/16/2007] [Indexed: 11/23/2022]
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Steiner E, Pollow K, Hasenclever D, Schormann W, Hermes M, Schmidt M, Puhl A, Brulport M, Bauer A, Petry IB, Koelbl H, Hengstler JG. Role of urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor type 1 (PAI-1) for prognosis in endometrial cancer. Gynecol Oncol 2008; 108:569-76. [PMID: 18222533 DOI: 10.1016/j.ygyno.2007.11.025] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2007] [Revised: 10/28/2007] [Accepted: 11/19/2007] [Indexed: 11/29/2022]
Abstract
BACKGROUND Urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor type 1 (PAI-1) contribute to the invasiveness of many carcinomas. Here, we studied a possible association between cytosolic uPA and PA-1 concentrations in tumor tissue with prognosis in patients with endometrial cancer. METHODS Cytosolic concentrations of uPA and PAI-1 were determined in 69 primary endothelial adenocarcinomas using an enzyme-linked immunoassay (ELISA). A possible influence of uPA and PAI-1 was studied by multivariate Cox regression adjusting for the established clinical prognostic factors FIGO-stage, grading, depth of invasion, diabetes mellitus and age. RESULTS Both uPA (p=0.011) and PAI-1 (p=0.003) were associated with relapse free time using the multivariate proportional hazards model. Association with overall survival was less pronounced with p=0.021 for uPA and p=0.358 for PAI-1. Concentrations of PAI-1 increased with FIGO stage (p=0.003) and with histological grading (p=0.005). Both uPA and PAI-1 concentrations were negatively correlated with estrogen and progesterone receptor levels. CONCLUSION The combination of high cytosolic concentrations of uPA (>5 ng/mg total protein) and high PAI-1 (>20 ng/mg total protein) may reveal a group of patients with increased risk of progression.
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Affiliation(s)
- E Steiner
- Department of Gynecology, University of Mainz, Mainz, Germany
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Katoh M, Tateno C, Yoshizato K, Yokoi T. Chimeric mice with humanized liver. Toxicology 2007; 246:9-17. [PMID: 18248870 DOI: 10.1016/j.tox.2007.11.012] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2007] [Revised: 11/09/2007] [Accepted: 11/12/2007] [Indexed: 02/06/2023]
Abstract
Recently, chimeric mice with humanized liver were established by transplanting human hepatocytes into an urokinase-type plasminogen activator(+/+)/severe combined immunodeficient transgenic mouse line. The replacement with human hepatocytes is more than 80-90% and is higher than any other chimeric mouse reported previously. In drug development, the liver is one of the most important organs because it is mainly involved in the pharmacokinetics of drugs and is frequently damaged by many drugs due to the accumulation of drugs and/or metabolites. The pharmacokinetics could affect the efficacy and toxicity of a drug, and thus prediction of the human pharmacokinetics is important for developing new drugs without adverse reactions and toxicity. Extrapolation from experimental animals or in vitro studies to the human in vivo pharmacokinetics is still difficult. To date, human hepatocytes and liver microsomes are recognized as better tools and are frequently used to estimate the human pharmacokinetics. We thought that chimeric mice with humanized liver could become a new tool for estimating the human toxicity and pharmacokinetics. At first, metabolism, which plays an essential role in pharmacokinetics, was investigated in the chimeric mice. In the liver of the chimeric mice, human drug metabolizing enzymes were found to be expressed and to reflect the capacities and genetic polymorphism of the donor. In an in vivo study on metabolism, human specific metabolites could be detected in the serum of the chimeric mice indicating that the chimeric mice could be used as an in vivo model to address human metabolism. These results suggested that the chimeric mice could overcome the species differences in drug metabolism and be used to evaluate drug toxicity due to genetic polymorphism. The reasons for drug interaction are often enzyme induction and inhibition. By the treatment with a typical inducer of cytochrome P450 (P450), which is the central drug-metabolizing enzyme, P450s expressed in the liver of the chimeric mice were found to possess induction potencies. After the treatment with a specific inhibitor of human P450, the area under the curve of the P450 metabolite was significantly decreased in the chimeric mice but not in the control mice. Therefore, it was indicated that the chimeric mice could be useful for assessing drug interactions in vivo. Moreover, drug excretion was determined to be humanized because cefmetazole was mainly excreted in urine both in the chimeric mice and humans but in the feces in control uPA(-/-)/SCID mice. Drug transporters expressed in the liver of the chimeric mice were also humanized. In this review, studies of the chimeric mice with humanized liver, particularly on metabolism and excretion, are summarized and the possibility of using the chimeric mice is proposed for the advanced prediction of human pharmacokinetics and toxicity.
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Affiliation(s)
- Miki Katoh
- Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
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Capela JP, Macedo C, Branco PS, Ferreira LM, Lobo AM, Fernandes E, Remião F, Bastos ML, Dirnagl U, Meisel A, Carvalho F. Neurotoxicity mechanisms of thioether ecstasy metabolites. Neuroscience 2007; 146:1743-57. [PMID: 17467183 DOI: 10.1016/j.neuroscience.2007.03.028] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2007] [Revised: 03/20/2007] [Accepted: 03/22/2007] [Indexed: 10/23/2022]
Abstract
3,4-Methylenedioxymethamphetamine (MDMA or "ecstasy"), is a widely abused, psychoactive recreational drug that is known to induce neurotoxic effects. Human and rat hepatic metabolism of MDMA involves N-demethylation to 3,4-methylenedioxyamphetamine (MDA), which is also a drug of abuse. MDMA and MDA are O-demethylenated to N-methyl-alpha-methyldopamine (N-Me-alpha-MeDA) and alpha-methyldopamine (alpha-MeDA), respectively, which are both catechols that can undergo oxidation to the corresponding ortho-quinones. Ortho-quinones may be conjugated with glutathione (GSH) to form glutathionyl adducts, which can be transported into the brain and metabolized to the correspondent N-acetylcysteine (NAC) adducts. In this study we evaluated the neurotoxicity of nine MDMA metabolites, obtained by synthesis: N-Me-alpha-MeDA, alpha-MeDA and their correspondent GSH and NAC adducts. The studies were conducted in rat cortical neuronal cultures, for a 6 h of exposure period, under normal (36.5 degrees C) and hyperthermic (40 degrees C) conditions. Our findings show that thioether MDMA metabolites are strong neurotoxins, significantly more than their correspondent parent catechols. On the other hand, N-Me-alpha-MeDA and alpha-MeDA are more neurotoxic than MDMA. GSH and NAC conjugates of N-Me-alpha-MeDA and alpha-MeDA induced a concentration dependent delayed neuronal death, accompanied by activation of caspase 3, which occurred earlier in hyperthermic conditions. Furthermore, thioether MDMA metabolites time-dependently increased the production of reactive species, concentration-dependently depleted intracellular GSH and increased protein bound quinones. Finally, thioether MDMA metabolites induced neuronal death and oxidative stress was prevented by NAC, an antioxidant and GSH precursor. This study provides new insights into the neurotoxicity mechanisms of thioether MDMA metabolites and highlights their importance in "ecstasy" neurotoxicity.
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Affiliation(s)
- J P Capela
- REQUIMTE (Rede de Química e Tecnologia), Toxicology Department, Faculty of Pharmacy, University of Porto, Rua Aníbal Cunha, 164, 4099-030 Porto, Portugal.
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Carmo H, Brulport M, Hermes M, Oesch F, de Boer D, Remião F, Carvalho F, Schön MR, Krebsfaenger N, Doehmer J, Bastos MDL, Hengstler JG. CYP2D6 increases toxicity of the designer drug 4-methylthioamphetamine (4-MTA). Toxicology 2007; 229:236-44. [PMID: 17156908 DOI: 10.1016/j.tox.2006.10.024] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2006] [Revised: 10/25/2006] [Accepted: 10/27/2006] [Indexed: 10/23/2022]
Abstract
4-Methylthioamphetamine (4-MTA) belongs to a group of new amphetamine derivatives that is usually sold as "ecstasy" or "flatliners" on the illicit drug market. Large interindividual differences in 4-MTA mediated toxicity have been reported in humans. Therefore, we tested whether CYP2D6 or its variant alleles as well as CYP3A4 influence the susceptibility to 4-MTA. For this purpose, we used the colony formation assay with Chinese hamster lung fibroblast V79 cells expressing human wild-type CYP2D6 (CYP2D6*1), the low activity alleles CYP2D6*2, CYP2D6*9, as well as human CYP3A4. The obtained results showed that the expression of wild type CYP2D6*1 clearly enhanced the susceptibility to the cytotoxic effects of 4-MTA compared with the parental cells devoid of CYP-dependent enzymatic activity. Toxicity in V79 CYP2D6*1 was also higher compared to the V79 cell lines expressing the low activity alleles CYP2D6*2 and CYP2D6*9. In contrast to CYP2D6, the CYP3A4 isoenzyme did not enhance 4-MTA toxicity. In conclusion, our results suggest that CYP2D6 rapid metabolizers may be more susceptible to 4-MTA toxicity than CYP2D6 poor metabolizers.
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Affiliation(s)
- Helena Carmo
- REQUIMTE, Toxicology Department, Faculty of Pharmacy, University of Porto, Rua Aníbal Cunha 164, 4099-030 Porto, Portugal.
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Silva R, Boldt S, Costa VM, Carmo H, Carvalho M, Carvalho F, Bastos MDL, Lemos-Amado F, Remião F. Evaluation of GSH adducts of adrenaline in biological samples. Biomed Chromatogr 2007; 21:670-9. [PMID: 17345573 DOI: 10.1002/bmc.796] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The sustained high release of catecholamines to circulation is a deleterious condition that may induce toxicity, which seems to be partially related to the products formed by oxidation of catecholamines that can be further conjugated with glutathione (GSH). The aim of the present study was to develop a method for the determination of GSH adducts of adrenaline in biological samples. Two position isomers of the glutathion-S-yl-adrenaline were synthesized and characterized by HPLC using diode array, coulometric and mass detectors. A method for the extraction of these adducts from human plasma was also developed, based on adsorption to activated alumina, which showed adequate recoveries and proved to be crucial in removing interferences from plasma. The selectivity, precision and linearity of the method were all within the accepted values for these parameters. Furthermore, the sensitivity of this method allows the detection of adduct amounts that are within the range of the expected concentrations for these adducts under certain pathophysiological conditions and/or drug treatments. In conclusion, the development of this method allows the direct analysis of GSH adducts of adrenaline in human plasma, providing a valuable tool for the study of the catecholamine oxidation process and its related toxicity.
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Affiliation(s)
- Renata Silva
- REQUIMTE, Serviço de Toxicologia, Faculdade de Farmácia, Universidade do Porto, Rua Aníbal Cunha, 164, 4099-030 Porto, Portugal
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Xu F. Effect of personality type on pharmacodynamics through changing pharmacokinetics. Med Hypotheses 2007; 69:1131-4. [PMID: 17448609 DOI: 10.1016/j.mehy.2007.01.079] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2007] [Accepted: 01/07/2007] [Indexed: 10/23/2022]
Abstract
A few studies have showed that there is an association between the genetic polymorphisms of drug-metabolizing enzyme, CYP2D6, to persons with different personality type. More and more evidences suggested that personality type is kind of behavioral or psychological factor which might influence the pharmacodynamics as well as patient's gender, age, disease, and genetic background. We hypothesized that personality affect the pharmacodynamics through changing pharmacokinetic mediated by different polymorphism of drug-metabolizing enzymes. Since many major diseases, from cancer to infectious disease, are involved with risky Type A personality, we appeal for attention to the clinical pharmacologist and psychiatrists further to study personality pharmacokinetics for individualized medicine.
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Affiliation(s)
- Feng Xu
- Department of Clinical Pharmacology, Second Medical College, Southern Medical University, Guangzhou, China.
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