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Xu JF, Lu JJ, Cao Y, Wang W, Li HH, Chen JG, Wang F, Wu PF. Sulforaphane alleviates ethanol-mediated central inhibition and reverses chronic stress-induced aggravation of acute alcoholism via targeting Nrf2-regulated catalase expression. Neuropharmacology 2020; 176:108235. [PMID: 32710977 DOI: 10.1016/j.neuropharm.2020.108235] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 06/12/2020] [Accepted: 07/07/2020] [Indexed: 01/09/2023]
Abstract
Acute ethanol intoxication by excessive drinking is an important cause of alcohol-induced death. Stress exposure has been identified as one risk factor for alcohol abuse. Previous reports indicated that stressors may augment inhibitory effects of alcohol, but the underlying mechanism remains unknown. Here, we reported that chronic unpredictable stress increased the sensitivity to the acute ethanol intoxication in mice via impairing nuclear factor (erythroid-derived 2)-like 2 (Nrf2)-catalase signaling. Nrf2 activity regulates the expression of catalase, a key antioxidant enzyme that mediates ethanol oxidation in the brain. Pharmacological blockade of catalase or Nrf2 activity significantly aggravated acute ethanol intoxication. Sulforaphane, a cruciferous vegetable-derived activator of Nrf2, significantly attenuated acute ethanol intoxication. Furthermore, the stress-induced aggravation of acute alcoholism was rapidly reversed by sulforaphane. Our findings suggest that Nrf2 may function as a novel drug target for the prevention of acute alcoholism, especially in psychiatric patients, by controlling catalase-mediated ethanol oxidation.
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Affiliation(s)
- Jun-Feng Xu
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Jia-Jing Lu
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yu Cao
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Wen Wang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Hou-Hong Li
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Jian-Guo Chen
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China; Laboratory of Neuropsychiatric Diseases, The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, 430030, China; Key Laboratory of Neurological Diseases (HUST), Ministry of Education of China, Wuhan, Hubei, 430030, China; The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, 430030, China
| | - Fang Wang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China; Laboratory of Neuropsychiatric Diseases, The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, 430030, China; Key Laboratory of Neurological Diseases (HUST), Ministry of Education of China, Wuhan, Hubei, 430030, China; The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, 430030, China
| | - Peng-Fei Wu
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China; Laboratory of Neuropsychiatric Diseases, The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, 430030, China; Key Laboratory of Neurological Diseases (HUST), Ministry of Education of China, Wuhan, Hubei, 430030, China; The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, 430030, China.
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Woodward TJ, Tesic V, Stamenic TT, Jevtovic-Todorovic V, Todorovic SM. Pharmacological Antagonism of T-Type Calcium Channels Constrains Rebound Burst Firing in Two Distinct Subpopulations of GABA Neurons in the Rat Ventral Tegmental Area: Implications for α-Lipoic Acid. Front Pharmacol 2019; 10:1402. [PMID: 31849661 PMCID: PMC6889856 DOI: 10.3389/fphar.2019.01402] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Accepted: 11/04/2019] [Indexed: 11/13/2022] Open
Abstract
The ventral tegmental area (VTA) is a midbrain region highly involved in motivation and reward. A large body of work has investigated synaptic plasticity and ion channel excitability in this area, which has strong implication in drug abuse. We recently provided electrophysiological and pharmacological evidence that the CaV3.1 isoform of T-type voltage-gated calcium channels contributes to the excitability of VTA dopamine (DA) neurons. However, the role of T-channels in excitability of VTA gamma-amino-butyric acid (GABA) neurons remained unaddressed. Here, with a population study of rat VTA GABA neurons, we provide evidence that T-channels contribute to rebound spiking activity in two phenotypically distinct subpopulations of GABAergic neurons, each with differing electrophysiological characteristics. Additionally, we provide the first study to investigate the effect of α-lipoic acid (ALA) on ion channels in mesolimbic reward circuitry. Taken together, our population study and pharmacology experiments implicate T-channels as a target for therapies aimed at tempering VTA and mesolimbic circuit excitability.
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Affiliation(s)
- Taylor Joel Woodward
- Program in Neuroscience, Indiana University-Bloomington, Bloomington, IN, United States.,Department of Psychological and Brain Sciences, Indiana University-Bloomington, Bloomington, IN, United States.,Department of Anesthesiology, University of Colorado, Aurora, CO, United States
| | - Vesna Tesic
- Department of Anesthesiology, University of Colorado, Aurora, CO, United States
| | | | | | - Slobodan M Todorovic
- Department of Anesthesiology, University of Colorado, Aurora, CO, United States.,Neuroscience Graduate Program, University of Colorado, Aurora, CO, United States
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Baliño P, Romero-Cano R, Sánchez-Andrés JV, Valls V, Aragón CG, Muriach M. Effects of Acute Ethanol Administration on Brain Oxidative Status: The Role of Acetaldehyde. Alcohol Clin Exp Res 2019; 43:1672-1681. [PMID: 31211868 DOI: 10.1111/acer.14133] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 06/11/2019] [Indexed: 12/12/2022]
Abstract
BACKGROUND Ethanol (EtOH), one of the most widely consumed substances of abuse, can induce brain damage and neurodegeneration. EtOH is centrally metabolized into acetaldehyde, which has been shown to be responsible for some of the neurophysiological and cellular effects of EtOH. Although some of the consequences of chronic EtOH administration on cell oxidative status have been described, the mechanisms by which acute EtOH administration affects the brain's cellular oxidative status and the role of acetaldehyde remain to be elucidated in detail. METHODS Swiss CD-I mice were pretreated with the acetaldehyde-sequestering agent d-penicillamine (DP; 75 mg/kg, i.p.) or the antioxidant lipoic acid (LA; 50 mg/kg, i.p.) 30 minutes before EtOH (2.5 g/kg, i.p.) administration. Animals were sacrificed 30 minutes after EtOH injection. Glutathione peroxidase (GPx) mRNA levels; GPx and glutathione reductase (GR) enzymatic activities; reduced glutathione (GSH), glutathione disulfide (GSSG), glutamate, g-L-glutamyl-L-cysteine (Glut-Cys), and malondialdehyde (MDA) concentrations; and protein carbonyl group (CG) content were determined in whole-brain samples. RESULTS Acute EtOH administration enhanced GPx activity and the GSH/GSSG ratio, while it decreased GR activity and GSSG concentration. Pretreatment with DP or LA only prevented GPx activity changes induced by EtOH. CONCLUSIONS Altogether, these results show the capacity of a single dose of EtOH to unbalance cellular oxidative homeostasis.
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Affiliation(s)
- Pablo Baliño
- From the, Unitat predepartamental de Medicina, (PB, RR-C, JVS-A, VV, MM), Universitat Jaume I, Castellón de la Plana, Spain
| | - Ricard Romero-Cano
- From the, Unitat predepartamental de Medicina, (PB, RR-C, JVS-A, VV, MM), Universitat Jaume I, Castellón de la Plana, Spain
| | - Juan Vicente Sánchez-Andrés
- From the, Unitat predepartamental de Medicina, (PB, RR-C, JVS-A, VV, MM), Universitat Jaume I, Castellón de la Plana, Spain
| | - Victoria Valls
- From the, Unitat predepartamental de Medicina, (PB, RR-C, JVS-A, VV, MM), Universitat Jaume I, Castellón de la Plana, Spain
| | | | - María Muriach
- From the, Unitat predepartamental de Medicina, (PB, RR-C, JVS-A, VV, MM), Universitat Jaume I, Castellón de la Plana, Spain
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4
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Peana AT, Pintus FA, Bennardini F, Rocchitta G, Bazzu G, Serra PA, Porru S, Rosas M, Acquas E. Is catalase involved in the effects of systemic and pVTA administration of 4-methylpyrazole on ethanol self-administration? Alcohol 2017; 63:61-73. [PMID: 28847383 DOI: 10.1016/j.alcohol.2017.04.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 01/31/2017] [Accepted: 04/03/2017] [Indexed: 12/31/2022]
Abstract
The oxidative metabolism of ethanol into acetaldehyde involves several enzymes, including alcohol dehydrogenase (ADH) and catalase-hydrogen peroxide (H2O2). In this regard, while it is well known that 4-methylpyrazole (4-MP) acts by inhibiting ADH in the liver, little attention has been placed on its ability to interfere with fatty acid oxidation-mediated generation of H2O2, a mechanism that may indirectly affect catalase whose enzymatic activity requires H2O2. The aim of our investigation was twofold: 1) to evaluate the effect of systemic (i.p. [intraperitoneal]) and local (into the posterior ventral tegmental area, pVTA) administration of 4-MP on oral ethanol self-administration, and 2) to assess ex vivo whether or not systemic 4-MP affects liver and brain H2O2 availability. The results show that systemic 4-MP reduced ethanol but not acetaldehyde or saccharin self-administration, and decreased the ethanol deprivation effect. Moreover, local intra-pVTA administration of 4-MP reduced ethanol but not saccharin self-administration. In addition, although unable to affect basal catalase activity, systemic administration of 4-MP decreased H2O2 availability both in liver and in brain. Overall, these results indicate that 4-MP interferes with ethanol self-administration and suggest that its behavioral effects could be due to a decline in catalase-H2O2 system activity as a result of a reduction of H2O2 availability, thus highlighting the role of central catalase-mediated metabolism of ethanol and further supporting the key role of acetaldehyde in the reinforcing properties of ethanol.
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Melis M, Carboni E, Caboni P, Acquas E. Key role of salsolinol in ethanol actions on dopamine neuronal activity of the posterior ventral tegmental area. Addict Biol 2015; 20:182-93. [PMID: 24103023 DOI: 10.1111/adb.12097] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ethanol excites dopamine (DA) neurons in the posterior ventral tegmental area (pVTA). This effect is responsible for ethanol's motivational properties and may contribute to alcoholism. Evidence indicates that catalase-mediated conversion of ethanol into acetaldehyde in pVTA plays a critical role in this effect. Acetaldehyde, in the presence of DA, condensates with it to generate salsolinol. Salsolinol, when administered in pVTA, excites pVTA DA cells, elicits DA transmission in nucleus accumbens and sustains its self-administration in pVTA. Here we show, by using ex vivo electrophysiology, that ethanol and acetaldehyde, but not salsolinol, failed to stimulate pVTA DA cell activity in mice administered α-methyl-p-tyrosine, a DA biosynthesis inhibitor that reduces somatodendritic DA release. This effect was specific for ethanol and acetaldehyde since morphine, similarly to salsolinol, was able to excite pVTA DA cells in α-methyl-p-tyrosine-treated mice. However, when DA was bath applied in slices from α-methyl-p-tyrosine-treated mice, ethanol-induced excitation of pVTA DA neurons was restored. This effect requires ethanol oxidation into acetaldehyde given that, when H2 O2 -catalase system was impaired by either 3-amino-1,2,4-triazole or in vivo administration of α-lipoic acid, ethanol did not enhance DA cell activity. Finally, high performance liquid chromatography-tandem mass spectrometry analysis of bath medium detected salsolinol only after co-application of ethanol and DA in α-methyl-p-tyrosine-treated mice. These results demonstrate the relationship between ethanol and salsolinol effects on pVTA DA neurons, help to untangle the mechanism(s) of action of ethanol in this area and contribute to an exciting research avenue prosperous of theoretical and practical consequences.
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Affiliation(s)
- Miriam Melis
- Department of Biomedical Sciences; University of Cagliari; Cagliari Italy
| | - Ezio Carboni
- Department of Biomedical Sciences; University of Cagliari; Cagliari Italy
- Centre of Excellence on Neurobiology of Addiction; University of Cagliari; Cagliari Italy
- INN-National Institute of Neuroscience; University of Cagliari; Cagliari Italy
| | - Pierluigi Caboni
- Department of Life and Environmental Sciences; University of Cagliari; Cagliari Italy
| | - Elio Acquas
- Department of Life and Environmental Sciences; University of Cagliari; Cagliari Italy
- Centre of Excellence on Neurobiology of Addiction; University of Cagliari; Cagliari Italy
- INN-National Institute of Neuroscience; University of Cagliari; Cagliari Italy
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6
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Immobility responses between mouse strains correlate with distinct hippocampal serotonin transporter protein expression and function. Int J Neuropsychopharmacol 2014; 17:1737-50. [PMID: 24833265 DOI: 10.1017/s146114571400073x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Mouse strain differences in immobility and in sensitivity to antidepressants have been observed in the forced swimming test (FST) and the tail suspension test (TST). However, the neurotransmitter systems and neural substrates that contribute to these differences remain unknown. To investigate the role of the hippocampal serotonin transporter (5-HTT), we measured baseline immobility and the immobility responses to fluoxetine (FLX) in the FST and the TST in male CD-1, C57BL/6, DBA and BALB/c mice. We observed strain differences in baseline immobility time, with CD-1 mice showing the longest and DBA mice showing the shortest. In contrast, DBA and BALB/c mice showed the highest sensitivity to FLX, whereas CD-1 and C57BL/6 mice showed the lowest sensitivity. Also we found strain differences in both the total 5-HTT protein level and the membrane-bound 5-HTT level (estimated by V max) as follows: DBA>BALB/c>CD-1=C57BL/6. The uptake efficiency of the membrane-bound 5-HTT (estimated by 1/K m) was highest in DBA and BALB/c mice and lowest in CD-1 and C57BL/6 mice. A correlation analysis of subregions within the hippocampus revealed that immobility time was negatively correlated with V max and positively correlated with K m in the hippocampus. Therefore a higher uptake capacity of the membrane-bound 5-HTT in the hippocampus was associated with lower baseline immobility and greater sensitivity to FLX. These results suggest that alterations in hippocampal 5-HTT activity may contribute to mouse strain differences in the FST and the TST.
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7
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Tarragon E, Baliño P, Aragon CMG. Centrally formed acetaldehyde mediates ethanol-induced brain PKA activation. Neurosci Lett 2014; 580:68-73. [PMID: 25093700 DOI: 10.1016/j.neulet.2014.07.046] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 07/24/2014] [Accepted: 07/25/2014] [Indexed: 11/28/2022]
Abstract
Centrally formed acetaldehyde has proven to be responsible for several psychopharmacological effects induced by ethanol. In addition, it has been suggested that the cAMP-PKA signaling transduction pathway plays an important role in the modulation of several ethanol-induced behaviors. Therefore, we hypothesized that acetaldehyde might be ultimately responsible for the activation of this intracellular pathway. We used three pharmacological agents that modify acetaldehyde activity (α-lipoic acid, aminotriazole, and d-penicillamine) to study the role of this metabolite on EtOH-induced PKA activation in mice. Our results show that the injection of α-lipoic acid, aminotriazole and d-penicillamine prior to acute EtOH administration effectively blocks the PKA-enhanced response to EtOH in the brain. These results strongly support the hypothesis of a selective release of acetaldehyde-dependent Ca(2+) as the mechanism involved in the neurobehavioral effects elicited by EtOH.
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Affiliation(s)
- E Tarragon
- Área de Psicobiología, Universitat Jaume I, Castellon de la Plana, Spain
| | - P Baliño
- Área de Psicobiología, Universitat Jaume I, Castellon de la Plana, Spain
| | - C M G Aragon
- Área de Psicobiología, Universitat Jaume I, Castellon de la Plana, Spain.
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8
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Induction of brain cytochrome P450 2E1 boosts the locomotor-stimulating effects of ethanol in mice. Neuropharmacology 2014; 85:36-44. [PMID: 24863043 DOI: 10.1016/j.neuropharm.2014.05.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 04/14/2014] [Accepted: 05/13/2014] [Indexed: 11/23/2022]
Abstract
In the central nervous system ethanol (EtOH) is metabolized into acetaldehyde by different enzymes. Brain catalase accounts for 60% of the total production of EtOH-derived acetaldehyde, whereas cerebral cytochrome P450 2E1 (CYP 2E1) produces 20% of this metabolite. Acetaldehyde formed by the activity of central catalase has been implicated in some of the neurobehavioral properties of EtOH, yet the contribution of CYP 2E1 to the pharmacological actions of this drug has not been investigated. Here we assessed the possible participation of CYP 2E1 in the behavioral effects of EtOH. Thus, we induced CYP 2E1 activity and expression by exposing mice to chronic acetone intake (1% v/v for 10 days) and examined its consequences on the stimulating and uncoordinating effects of EtOH (0-3.2 g/kg) injected intraperitoneally. Our data showed that 24 h after withdrawal of acetone brain expression and activity of CYP 2E1 was induced. Furthermore, the locomotion produced by EtOH was boosted over the same interval of time. Locomotor stimulation produced by amphetamine or tert-butanol was unchanged by previous treatment with acetone. EtOH-induced motor impairment as evaluated in a Rota-Rod apparatus was unaffected by the preceding exposure to acetone. These results indicate that cerebral CYP 2E1 activity could contribute to the locomotor-stimulating effects of EtOH, and therefore we suggest that centrally produced acetaldehyde might be a possible mediator of some EtOH-induced pharmacological effects.
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9
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Ledesma JC, Escrig MA, Pastor R, Aragon CM. The MAO-A inhibitor clorgyline reduces ethanol-induced locomotion and its volitional intake in mice. Pharmacol Biochem Behav 2014; 116:30-8. [DOI: 10.1016/j.pbb.2013.11.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 09/26/2013] [Accepted: 11/08/2013] [Indexed: 01/31/2023]
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10
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Ledesma JC, Baliño P, Aragon CMG. Reduction in central H2O2 levels prevents voluntary ethanol intake in mice: a role for the brain catalase-H2O2 system in alcohol binge drinking. Alcohol Clin Exp Res 2013; 38:60-7. [PMID: 24033657 DOI: 10.1111/acer.12253] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Accepted: 05/28/2013] [Indexed: 11/26/2022]
Abstract
BACKGROUND Hydrogen peroxide (H2 O2 ) is the cosubstrate used by the enzyme catalase to form Compound I (the catalase-H2 O2 system), which is the major pathway for the conversion of ethanol (EtOH) into acetaldehyde in the brain. This centrally formed acetaldehyde has been shown to be involved in some of the psychopharmacological effects induced by EtOH in rodents, including voluntary alcohol intake. It has been observed that different levels of this enzyme in the central nervous system (CNS) result in variations in the amount of EtOH consumed. This has been interpreted to mean that the brain catalase-H2 O2 system, by determining EtOH metabolism, mediates alcohol self-administration. To date, however, the role of H2 O2 in voluntary EtOH drinking has not been investigated. METHODS In the present study, we explored the consequence of a reduction in cerebral H2 O2 levels in volitional EtOH ingestion. With this end in mind, we injected mice of the C57BL/6J strain intraperitoneally with the H2 O2 scavengers alpha-lipoic acid (LA; 0 to 50 mg/kg) or ebselen (Ebs; 0 to 25 mg/kg) 15 or 60 minutes, respectively, prior to offering them an EtOH (10%) solution following a drinking-in-the-dark procedure. The same procedure was followed to assess the selectivity of these compounds in altering EtOH intake by presenting mice with a (0.1%) solution of saccharin. In addition, we indirectly tested the ability of LA and Ebs to reduce brain H2 O2 availability. RESULTS The results showed that both LA and Ebs dose-dependently reduced voluntary EtOH intake, without altering saccharin consumption. Moreover, we demonstrated that these treatments decreased the central H2 O2 levels available to catalase. CONCLUSIONS Therefore, we propose that the amount of H2 O2 present in the CNS, by determining brain acetaldehyde formation by the catalase-H2 O2 system, could be a factor that determines an animal's propensity to consume EtOH.
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Muggironi G, Fois GR, Diana M. Ethanol-derived acetaldehyde: pleasure and pain of alcohol mechanism of action. Front Behav Neurosci 2013; 7:87. [PMID: 23882197 PMCID: PMC3713400 DOI: 10.3389/fnbeh.2013.00087] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 06/29/2013] [Indexed: 11/13/2022] Open
Abstract
Acetaldehyde (ACD), the first metabolite of ethanol (EtOH), has been implicated in several actions of alcohol, including its reinforcing effects. Previously considered an aversive compound, ACD was useful in alcoholic’s pharmacological treatment aimed at discouraging alcohol drinking. However, it has recently been shown that EtOH-derived ACD is necessary for EtOH-induced place preference and self-administration, thereby suggesting a possible involvement of ACD in EtOH motivational properties. In addition, EtOH-stimulating properties on DA neurons are prevented by pharmacological blockade of local catalase H2O2 system, the main metabolic step for biotransformation of EtOH into ACD within the central nervous system. It was further shown that pretreatment with thiol compounds, like L-Cysteine or D-Penicillamine, reduced EtOH and ACD-induced motivational effects, in fact preventing self-administration of both EtOH and ACD, thus suggesting a possible role for ACD as a biomarker useful in evaluating potential innovative treatments of alcohol abuse. These findings suggest a key role of ACD in the EtOH reinforcing effects. In the present paper we review the role of EtOH-derived ACD in the reinforcing effects of EtOH and the possibility that ACD may serve as a therapeutically targetable biomarker in the search for novel treatments in alcohol abuse and alcoholism.
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Affiliation(s)
- Giulia Muggironi
- 'G. Minardi' Laboratory of Cognitive Neuroscience, Department of Chemistry and Pharmacy, University of Sassari Sassari, Italy
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12
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Peana AT, Acquas E. Behavioral and biochemical evidence of the role of acetaldehyde in the motivational effects of ethanol. Front Behav Neurosci 2013; 7:86. [PMID: 23874276 PMCID: PMC3710953 DOI: 10.3389/fnbeh.2013.00086] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 06/27/2013] [Indexed: 11/13/2022] Open
Abstract
Since Chevens' report, in the early 50's that his patients under treatment with the aldehyde dehydrogenase inhibitor, antabuse, could experience beneficial effects when drinking small volumes of alcoholic beverages, the role of acetaldehyde (ACD) in the effects of ethanol has been thoroughly investigated on pre-clinical grounds. Thus, after more than 25 years of intense research, a large number of studies have been published on the motivational properties of ACD itself as well as on the role that ethanol-derived ACD plays in the effects of ethanol. Accordingly, in particular with respect to the motivational properties of ethanol, these studies were developed following two main strategies: on one hand, were aimed to challenge the suggestion that also ACD may exert motivational properties on its own, while, on the other, with the aid of enzymatic manipulations or ACD inactivation, were aimed to test the hypothesis that ethanol-derived ACD might have a role in ethanol motivational effects. Furthermore, recent evidence significantly contributed to highlight, as possible mechanisms of action of ACD, its ability to commit either dopaminergic and opioidergic transmission as well as to activate the Extracellular signal Regulated Kinase cascade transduction pathway in reward-related brain structures. In conclusion, and despite the observation that ACD seems also to have inherited the elusive nature of its parent compound, the behavioral and biochemical evidence reviewed points to ACD as a neuroactive molecule able, on its own and as ethanol metabolite, to exert motivational effects.
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Affiliation(s)
- Alessandra T Peana
- Department of Chemistry and Pharmacy, University of Sassari Sassari, Italy
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13
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Peana AT, Muggironi G, Fois G, Diana M. Alpha-lipoic acid reduces ethanol self-administration in rats. Alcohol Clin Exp Res 2013; 37:1816-22. [PMID: 23802909 DOI: 10.1111/acer.12169] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 03/17/2013] [Indexed: 01/20/2023]
Abstract
BACKGROUND The main system of central ethanol (EtOH) oxidation is mediated by the enzyme catalase. By reacting with H2 O2 , brain catalase forms compound I (the catalase-H2 O2 system), which is able to oxidize EtOH to acetaldehyde (ACD) in the brain. We have previously shown that ACD regulates EtOH motivational properties and possesses reinforcing effects by itself. In this study, we investigate the effects of alpha-lipoic acid (ALA), a scavenging agent for H2 O2 , on oral EtOH self-administration. METHODS To this end, we trained Wistar rats to orally self-administer EtOH (10%) by nose poking. The effect of intraperitoneal pretreatment with ALA was evaluated during (i) maintenance of EtOH self-administration, (ii) EtOH self-administration under a progressive ratio (PR) schedule of reinforcement, and (iii) oral EtOH priming to induce reinstatement of EtOH seeking behavior. Moreover, we tested the effect of ALA on saccharin (0.05%) reinforcement, as assessed by oral self-administration. RESULTS The results indicate that ALA dose-dependently reduced the maintenance, the break point of EtOH self-administration under a PR and the reinstatement of EtOH seeking behavior without suppressing saccharin self-administration. CONCLUSIONS These results support that ALA may have a potential use in alcoholism treatment.
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Affiliation(s)
- Alessandra T Peana
- Laboratory of Cognitive Neuroscience (ATP, GM, GF, MD), Department of Chemistry and Pharmacy, University of Sassari, Sassari, Italy
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14
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Ledesma JC, Aragon CMG. Acquisition and reconditioning of ethanol-induced conditioned place preference in mice is blocked by the H₂O₂ scavenger alpha lipoic acid. Psychopharmacology (Berl) 2013; 226:673-85. [PMID: 22885873 DOI: 10.1007/s00213-012-2831-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Accepted: 07/26/2012] [Indexed: 12/30/2022]
Abstract
RATIONALE Hydrogen peroxide (H2O2) is the co-substrate used by catalase to metabolize ethanol to acetaldehyde in the brain. This centrally formed acetaldehyde has been involved in several ethanol-related behaviors. OBJECTIVES The present research evaluated the effect of the H2O2 scavenger, alpha lipoic acid (LA), on the acquisition and reconditioning of ethanol-induced conditioned place preference (CPP). METHODS Mice received pairings of a distinctive floor stimulus (CS+) associated with intraperitoneal injections of ethanol (2.5 g/kg). On alternate days, animals received pairings of a different floor stimulus (CS-) associated with saline injections. A different group of animals received pairings with the (CS-) associated with saline injections, and on alternate days they received LA (100 mg/kg) injected 30 min prior to ethanol (2.5 g/kg) administration paired with the (CS+). A preference test assessed the effect of LA on the acquisition of ethanol-induced CPP. A similar procedure was followed to study the effect of LA on the acquisition of cocaine- and morphine-induced CPP. A separate experiment evaluated the effect of LA on the reconditioning of ethanol-induced CPP. In addition, we investigated the consequence of LA administration on central H2O2 levels. RESULTS LA selectively blocked the acquisition of ethanol-induced CPP. Moreover, this compound impaired the reconditioning of ethanol-induced CPP. Additionally, we found that LA diminished H2O2 levels in the brain. CONCLUSIONS These data suggest that a decline in H2O2 availability by LA might impede the formation of brain ethanol-derived acetaldehyde by catalase, which results in an impairment of the rewarding properties of ethanol.
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Affiliation(s)
- Juan Carlos Ledesma
- Area de Psicobiologia, Universitat Jaume I, Avenida Sos Baynat s/n, 12071, Castellón, Spain
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Ledesma JC, Font L, Aragon CMG. The H2O2 scavenger ebselen decreases ethanol-induced locomotor stimulation in mice. Drug Alcohol Depend 2012; 124:42-9. [PMID: 22261181 DOI: 10.1016/j.drugalcdep.2011.12.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Revised: 10/28/2011] [Accepted: 12/01/2011] [Indexed: 10/14/2022]
Abstract
BACKGROUND In the brain, the enzyme catalase by reacting with H(2)O(2) forms Compound I (catalase-H(2)O(2) system), which is the main system of central ethanol metabolism to acetaldehyde. Previous research has demonstrated that acetaldehyde derived from central-ethanol metabolism mediates some of the psychopharmacological effects produced by ethanol. Manipulations that modulate central catalase activity or sequester acetaldehyde after ethanol administration modify the stimulant effects induced by ethanol in mice. However, the role of H(2)O(2) in the behavioral effects caused by ethanol has not been clearly addressed. The present study investigated the effects of ebselen, an H(2)O(2) scavenger, on ethanol-induced locomotion. METHODS Swiss RjOrl mice were pre-treated with ebselen (0-50mg/kg) intraperitoneally (IP) prior to administration of ethanol (0-3.75g/kg; IP). In another experiment, animals were pre-treated with ebselen (0 or 25mg/kg; IP) before caffeine (15mg/kg; IP), amphetamine (2mg/kg; IP) or cocaine (10mg/kg; IP) administration. Following these treatments, animals were placed in an open field to measure their locomotor activity. Additionally, we evaluated the effect of ebselen on the H(2)O(2)-mediated inactivation of brain catalase activity by 3-amino-1,2,4-triazole (AT). RESULTS Ebselen selectively prevented ethanol-induced locomotor stimulation without altering the baseline activity or the locomotor stimulating effects caused by caffeine, amphetamine and cocaine. Ebselen reduced the ability of AT to inhibit brain catalase activity. CONCLUSIONS Taken together, these data suggest that a decline in H(2)O(2) levels might result in a reduction of the ethanol locomotor-stimulating effects, indicating a possible role for H(2)O(2) in some of the psychopharmacological effects produced by ethanol.
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Affiliation(s)
- Juan Carlos Ledesma
- Àrea de Psicobiologia, Universitat Jaume I, Avda Sos Baynat, 12071 Castellón, Spain
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