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Castro-Nin JP, Serantes D, Rodriguez P, Gonzalez B, Carrera I, Torterolo P, González J. Noribogaine acute administration in rats promotes wakefulness and suppresses REM sleep. Psychopharmacology (Berl) 2024:10.1007/s00213-024-06572-2. [PMID: 38467891 DOI: 10.1007/s00213-024-06572-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 03/05/2024] [Indexed: 03/13/2024]
Abstract
Ibogaine is a potent atypical psychedelic that has gained considerable attention due to its antiaddictive and antidepressant properties in preclinical and clinical studies. Previous research from our group showed that ibogaine suppresses sleep and produces an altered wakefulness state, which resembles natural REM sleep. However, after systemic administration, ibogaine is rapidly metabolized to noribogaine, which also shows antiaddictive effects but with a distinct pharmacological profile, making this drug a promising therapeutic candidate. Therefore, we still ignore whether the sleep/wake alterations depend on ibogaine or its principal metabolite noribogaine. To answer this question, we conducted polysomnographic recordings in rats following the administration of pure noribogaine. Our results show that noribogaine promotes wakefulness while reducing slow-wave sleep and blocking REM sleep, similar to our previous results reported for ibogaine administration. Thus, we shed new evidence on the mechanisms by which iboga alkaloids work in the brain.
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Affiliation(s)
- Juan Pedro Castro-Nin
- Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, 11800, Uruguay
| | - Diego Serantes
- Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, 11800, Uruguay
| | - Paola Rodriguez
- Laboratorio de Síntesis Orgánica, Departamento de Química Orgánica, Facultad de Química, Universidad de la República, Montevideo, 11800, Uruguay
| | - Bruno Gonzalez
- Laboratorio de Síntesis Orgánica, Departamento de Química Orgánica, Facultad de Química, Universidad de la República, Montevideo, 11800, Uruguay
| | - Ignacio Carrera
- Laboratorio de Síntesis Orgánica, Departamento de Química Orgánica, Facultad de Química, Universidad de la República, Montevideo, 11800, Uruguay
| | - Pablo Torterolo
- Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, 11800, Uruguay.
| | - Joaquín González
- Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, 11800, Uruguay.
- Brain Institute, Federal University of Rio Grande do Norte, Natal, RN, 59078, Brazil.
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Wasko MJ, Witt-Enderby PA, Surratt CK. DARK Classics in Chemical Neuroscience: Ibogaine. ACS Chem Neurosci 2018; 9:2475-2483. [PMID: 30216039 DOI: 10.1021/acschemneuro.8b00294] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The West African iboga plant has been used for centuries by the Bwiti and Mbiri tribes to induce hallucinations during religious ceremonies. Ibogaine, the principal alkaloid responsible for iboga's psychedelic properties, was isolated and sold as an antidepressant in France for decades before its adverse effects precipitated its removal from the market. An ibogaine resurgence in the 1960s was driven by U.S. heroin addicts who claimed that ibogaine cured their opiate addictions. Behavioral pharmacologic studies in animal models provided evidence that ibogaine could blunt self-administration of not only opiates but cocaine, amphetamines, and nicotine. Ibogaine displays moderate-to-weak affinities for a wide spectrum of receptor and transporter proteins; recent work suggests that its actions at nicotinic acetylcholine receptor subtypes may underlie its reputed antiopiate effects. At micromolar levels, ibogaine is neurotoxic and cardiotoxic and has been linked to several deaths by cardiac arrest. Structure-activity studies led to the isolation of the ibogaine analog 18-methoxycoronaridine (18-MC), an α3β4 nicotinic receptor modulator that retains ibogaine's anticraving properties with few or no adverse effects. Clinical trials of 18-MC treatment of nicotine addiction are pending. Ibogaine analogs may also hold promise for treating anxiety and depression via the "psychedelic-assisted therapy" approach that employs hallucinogens including psilocybin and methylenedioxymethamphetamine ("ecstasy").
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Affiliation(s)
- Michael J. Wasko
- Division of Pharmaceutical, Administrative and Social Sciences, Duquesne University School of Pharmacy, 600 Forbes Avenue, Pittsburgh, Pennsylvania 15282, United States
| | - Paula A. Witt-Enderby
- Division of Pharmaceutical, Administrative and Social Sciences, Duquesne University School of Pharmacy, 600 Forbes Avenue, Pittsburgh, Pennsylvania 15282, United States
| | - Christopher K. Surratt
- Arnold & Marie Schwartz College of Pharmacy and Health Sciences, Long Island University−Brooklyn, 75 DeKalb Avenue, Brooklyn, New York 11201, United States
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González J, Prieto JP, Rodríguez P, Cavelli M, Benedetto L, Mondino A, Pazos M, Seoane G, Carrera I, Scorza C, Torterolo P. Ibogaine Acute Administration in Rats Promotes Wakefulness, Long-Lasting REM Sleep Suppression, and a Distinctive Motor Profile. Front Pharmacol 2018; 9:374. [PMID: 29755349 PMCID: PMC5934978 DOI: 10.3389/fphar.2018.00374] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 04/03/2018] [Indexed: 12/20/2022] Open
Abstract
Ibogaine is a potent psychedelic alkaloid that has been the focus of intense research because of its intriguing anti-addictive properties. According to anecdotic reports, ibogaine has been originally classified as an oneirogenic psychedelic; i.e., induces a dream-like cognitive activity while awake. However, the effects of ibogaine administration on wakefulness (W) and sleep have not been thoroughly assessed. The main aim of our study was to characterize the acute effects of ibogaine administration on W and sleep. For this purpose, polysomnographic recordings on chronically prepared rats were performed in the light phase during 6 h. Animals were treated with ibogaine (20 and 40 mg/kg) or vehicle, immediately before the beginning of the recordings. Furthermore, in order to evaluate associated motor behaviors during the W period, a different group of animals was tested for 2 h after ibogaine treatment on an open field with video-tracking software. Compared to control, animals treated with ibogaine showed an increase in time spent in W. This effect was accompanied by a decrease in slow wave sleep (SWS) and rapid-eye movements (REM) sleep time. REM sleep latency was significantly increased in animals treated with the higher ibogaine dose. While the effects on W and SWS were observed during the first 2 h of recordings, the decrement in REM sleep time was observed throughout the recording time. Accordingly, ibogaine treatment with the lower dose promoted an increase on locomotion, while tremor and flat body posture were observed only with the higher dose in a time-dependent manner. In contrast, head shake response, a behavior which has been associated in rats with the 5HT2A receptor activation by hallucinogens, was not modified. We conclude that ibogaine promotes a waking state that is accompanied by a robust and long-lasting REM sleep suppression. In addition, it produces a dose-dependent unusual motor profile along with other serotonin-related behaviors. Since ibogaine is metabolized to produce noribogaine, further experiments are needed to elucidate if the metabolite and/or the parent drug produced these effects.
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Affiliation(s)
- Joaquín González
- Laboratorio de Neurobiología del Sueño, Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - José P Prieto
- Departamento de Neurofarmacología Experimental, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - Paola Rodríguez
- Laboratorio de Síntesis Orgánica, Departamento de Química Orgánica, Facultad de Química, Universidad de la República, Montevideo, Uruguay
| | - Matías Cavelli
- Laboratorio de Neurobiología del Sueño, Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Luciana Benedetto
- Laboratorio de Neurobiología del Sueño, Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Alejandra Mondino
- Laboratorio de Neurobiología del Sueño, Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Mariana Pazos
- Laboratorio de Síntesis Orgánica, Departamento de Química Orgánica, Facultad de Química, Universidad de la República, Montevideo, Uruguay
| | - Gustavo Seoane
- Laboratorio de Síntesis Orgánica, Departamento de Química Orgánica, Facultad de Química, Universidad de la República, Montevideo, Uruguay
| | - Ignacio Carrera
- Laboratorio de Síntesis Orgánica, Departamento de Química Orgánica, Facultad de Química, Universidad de la República, Montevideo, Uruguay
| | - Cecilia Scorza
- Departamento de Neurofarmacología Experimental, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - Pablo Torterolo
- Laboratorio de Neurobiología del Sueño, Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
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Brown TK, Alper K. Treatment of opioid use disorder with ibogaine: detoxification and drug use outcomes. THE AMERICAN JOURNAL OF DRUG AND ALCOHOL ABUSE 2017; 44:24-36. [PMID: 28541119 DOI: 10.1080/00952990.2017.1320802] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
BACKGROUND Ibogaine is a monoterpene indole alkaloid used in medical and nonmedical settings for the treatment of opioid use disorder. Its mechanism of action is apparently novel. There are no published prospective studies of drug use outcomes with ibogaine. OBJECTIVES To study outcomes following opioid detoxification with ibogaine. METHODS In this observational study, 30 subjects with DSM-IV Opioid Dependence (25 males, 5 females) received a mean total dose of 1,540 ± 920 mg ibogaine HCl. Subjects used oxycodone (n = 21; 70%) and/or heroin (n = 18; 60%) in respective amounts of 250 ± 180 mg/day and 1.3 ± 0.94 g/day, and averaged 3.1 ± 2.6 previous episodes of treatment for opioid dependence. Detoxification and follow-up outcomes at 1, 3, 6, 9, and 12 months were evaluated utilizing the Subjective Opioid Withdrawal Scale (SOWS) and Addiction Severity Index Composite (ASIC) scores, respectively. RESULTS SOWS scores decreased from 31.0 ± 11.6 pretreatment to 14.0 ± 9.8 at 76.5 ± 30 hours posttreatment (t = 7.07, df = 26, p < 0.001). At 1-month posttreatment follow-up, 15 subjects (50%) reported no opioid use during the previous 30 days. ASIC Drug Use and Legal and Family/Social Status scores were improved relative to pretreatment baseline at all posttreatment time points (p < .001). Improvement in Drug Use scores was maximal at 1 month, and subsequently sustained from 3 to 12 months at levels that did not reach equivalence to the effect at 1 month. CONCLUSION Ibogaine was associated with substantive effects on opioid withdrawal symptoms and drug use in subjects for whom other treatments had been unsuccessful, and may provide a useful prototype for discovery and development of innovative pharmacotherapy of addiction.
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Affiliation(s)
| | - Kenneth Alper
- b Departments of Psychiatry and Neurology , New York University School of Medicine , New York , NY , USA
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Maillet EL, Milon N, Heghinian MD, Fishback J, Schürer SC, Garamszegi N, Mash DC. Noribogaine is a G-protein biased κ-opioid receptor agonist. Neuropharmacology 2015; 99:675-88. [PMID: 26302653 DOI: 10.1016/j.neuropharm.2015.08.032] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 08/18/2015] [Accepted: 08/19/2015] [Indexed: 10/23/2022]
Abstract
Noribogaine is the long-lived human metabolite of the anti-addictive substance ibogaine. Noribogaine efficaciously reaches the brain with concentrations up to 20 μM after acute therapeutic dose of 40 mg/kg ibogaine in animals. Noribogaine displays atypical opioid-like components in vivo, anti-addictive effects and potent modulatory properties of the tolerance to opiates for which the mode of action remained uncharacterized thus far. Our binding experiments and computational simulations indicate that noribogaine may bind to the orthosteric morphinan binding site of the opioid receptors. Functional activities of noribogaine at G-protein and non G-protein pathways of the mu and kappa opioid receptors were characterized. Noribogaine was a weak mu antagonist with a functional inhibition constants (Ke) of 20 μM at the G-protein and β-arrestin signaling pathways. Conversely, noribogaine was a G-protein biased kappa agonist 75% as efficacious as dynorphin A at stimulating GDP-GTP exchange (EC50=9 μM) but only 12% as efficacious at recruiting β-arrestin, which could contribute to the lack of dysphoric effects of noribogaine. In turn, noribogaine functionally inhibited dynorphin-induced kappa β-arrestin recruitment and was more potent than its G-protein agonistic activity with an IC50 of 1 μM. This biased agonist/antagonist pharmacology is unique to noribogaine in comparison to various other ligands including ibogaine, 18-MC, nalmefene, and 6'-GNTI. We predict noribogaine to promote certain analgesic effects as well as anti-addictive effects at effective concentrations>1 μM in the brain. Because elevated levels of dynorphins are commonly observed and correlated with anxiety, dysphoric effects, and decreased dopaminergic tone, a therapeutically relevant functional inhibition bias to endogenously released dynorphins by noribogaine might be worthy of consideration for treating anxiety and substance related disorders.
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Affiliation(s)
- Emeline L Maillet
- DemeRx, Inc., R&D Laboratory, Life Science & Technology Park, 1951 NW 7th Ave, Suite 300, Miami, FL 33136, USA.
| | - Nicolas Milon
- DemeRx, Inc., R&D Laboratory, Life Science & Technology Park, 1951 NW 7th Ave, Suite 300, Miami, FL 33136, USA
| | - Mari D Heghinian
- DemeRx, Inc., R&D Laboratory, Life Science & Technology Park, 1951 NW 7th Ave, Suite 300, Miami, FL 33136, USA
| | - James Fishback
- DemeRx, Inc., R&D Laboratory, Life Science & Technology Park, 1951 NW 7th Ave, Suite 300, Miami, FL 33136, USA
| | - Stephan C Schürer
- University of Miami, Center for Computational Science, 1320 S, Dixie Highway, Gables One Tower #600.H, Locator Code 2965, Coral Gables, FL 33146-2926, USA; Miller School of Medicine, Molecular and Cellular Pharmacology, 14th Street CRB 650 (M-857), Miami, FL 33136, USA
| | - Nandor Garamszegi
- DemeRx, Inc., R&D Laboratory, Life Science & Technology Park, 1951 NW 7th Ave, Suite 300, Miami, FL 33136, USA
| | - Deborah C Mash
- DemeRx, Inc., R&D Laboratory, Life Science & Technology Park, 1951 NW 7th Ave, Suite 300, Miami, FL 33136, USA
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Effect of Iboga alkaloids on µ-opioid receptor-coupled G protein activation. PLoS One 2013; 8:e77262. [PMID: 24204784 PMCID: PMC3818563 DOI: 10.1371/journal.pone.0077262] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Accepted: 08/31/2013] [Indexed: 01/13/2023] Open
Abstract
OBJECTIVE The iboga alkaloids are a class of small molecules defined structurally on the basis of a common ibogamine skeleton, some of which modify opioid withdrawal and drug self-administration in humans and preclinical models. These compounds may represent an innovative approach to neurobiological investigation and development of addiction pharmacotherapy. In particular, the use of the prototypic iboga alkaloid ibogaine for opioid detoxification in humans raises the question of whether its effect is mediated by an opioid agonist action, or if it represents alternative and possibly novel mechanism of action. The aim of this study was to independently replicate and extend evidence regarding the activation of μ-opioid receptor (MOR)-related G proteins by iboga alkaloids. METHODS Ibogaine, its major metabolite noribogaine, and 18-methoxycoronaridine (18-MC), a synthetic congener, were evaluated by agonist-stimulated guanosine-5´-O-(γ-thio)-triphosphate ([(35)S]GTPγS) binding in cells overexpressing the recombinant MOR, in rat thalamic membranes, and autoradiography in rat brain slices. RESULTS AND SIGNIFICANCE In rat thalamic membranes ibogaine, noribogaine and 18-MC were MOR antagonists with functional Ke values ranging from 3 uM (ibogaine) to 13 uM (noribogaine and 18MC). Noribogaine and 18-MC did not stimulate [(35)S]GTPγS binding in Chinese hamster ovary cells expressing human or rat MORs, and had only limited partial agonist effects in human embryonic kidney cells expressing mouse MORs. Ibogaine did not did not stimulate [(35)S]GTPγS binding in any MOR expressing cells. Noribogaine did not stimulate [(35)S]GTPγS binding in brain slices using autoradiography. An MOR agonist action does not appear to account for the effect of these iboga alkaloids on opioid withdrawal. Taken together with existing evidence that their mechanism of action also differs from that of other non-opioids with clinical effects on opioid tolerance and withdrawal, these findings suggest a novel mechanism of action, and further justify the search for alternative targets of iboga alkaloids.
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Alper KR, Stajić M, Gill JR. Fatalities temporally associated with the ingestion of ibogaine. J Forensic Sci 2012; 57:398-412. [PMID: 22268458 DOI: 10.1111/j.1556-4029.2011.02008.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ibogaine is a naturally occurring psychoactive plant alkaloid that is used globally in medical and nonmedical settings for opioid detoxification and other substance use indications. All available autopsy, toxicological, and investigative reports were systematically reviewed for the consecutive series of all known fatalities outside of West Central Africa temporally related to the use of ibogaine from 1990 through 2008. Nineteen individuals (15 men, four women between 24 and 54 years old) are known to have died within 1.5-76 h of taking ibogaine. The clinical and postmortem evidence did not suggest a characteristic syndrome of neurotoxicity. Advanced preexisting medical comorbidities, which were mainly cardiovascular, and/or one or more commonly abused substances explained or contributed to the death in 12 of the 14 cases for which adequate postmortem data were available. Other apparent risk factors include seizures associated with withdrawal from alcohol and benzodiazepines and the uninformed use of ethnopharmacological forms of ibogaine.
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Affiliation(s)
- Kenneth R Alper
- Department of Psychiatry, New York University School of Medicine, New York, NY 10016, USA.
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Alper KR, Lotsof HS, Kaplan CD. The ibogaine medical subculture. JOURNAL OF ETHNOPHARMACOLOGY 2008; 115:9-24. [PMID: 18029124 DOI: 10.1016/j.jep.2007.08.034] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2007] [Revised: 08/21/2007] [Accepted: 08/21/2007] [Indexed: 05/25/2023]
Abstract
AIM OF THE STUDY Ibogaine is a naturally occurring psychoactive indole alkaloid that is used to treat substance-related disorders in a global medical subculture, and is of interest as an ethnopharmacological prototype for experimental investigation and possible rational pharmaceutical development. The subculture is also significant for risks due to the lack of clinical and pharmaceutical standards. This study describes the ibogaine medical subculture and presents quantitative data regarding treatment and the purpose for which individuals have taken ibogaine. MATERIALS AND METHODS All identified ibogaine "scenes" (defined as a provider in an associated setting) apart from the Bwiti religion in Africa were studied with intensive interviewing, review of the grey literature including the Internet, and the systematic collection of quantitative data. RESULTS Analysis of ethnographic data yielded a typology of ibogaine scenes, "medical model", "lay provider/treatment guide", "activist/self-help", and "religious/spiritual". An estimated 3414 individuals had taken ibogaine as of February 2006, a fourfold increase relative to 5 years earlier, with 68% of the total having taken it for the treatment of a substance-related disorder, and 53% specifically for opioid withdrawal. CONCLUSIONS Opioid withdrawal is the most common reason for which individuals took ibogaine. The focus on opioid withdrawal in the ibogaine subculture distinguishes ibogaine from other agents commonly termed "psychedelics", and is consistent with experimental research and case series evidence indicating a significant pharmacologically mediated effect of ibogaine in opioid withdrawal.
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Affiliation(s)
- Kenneth R Alper
- Department of Psychiatry, New York University School of Medicine, New York, NY 10016, USA.
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Glick SD, Maisonneuve IM, Szumlinski KK. Mechanisms of action of ibogaine: relevance to putative therapeutic effects and development of a safer iboga alkaloid congener. THE ALKALOIDS. CHEMISTRY AND BIOLOGY 2002; 56:39-53. [PMID: 11705115 DOI: 10.1016/s0099-9598(01)56006-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- S D Glick
- Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany, NY 12208, USA
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Baumann MH, Pablo J, Ali SF, Rothman RB, Mash DC. Comparative neuropharmacology of ibogaine and its O-desmethyl metabolite, noribogaine. THE ALKALOIDS. CHEMISTRY AND BIOLOGY 2002; 56:79-113. [PMID: 11705118 DOI: 10.1016/s0099-9598(01)56009-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- M H Baumann
- Clinical Psychopharmacology Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD 21224, USA
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Glick SD, Maisonneuve IM, Szumlinski KK. 18-Methoxycoronaridine (18-MC) and ibogaine: comparison of antiaddictive efficacy, toxicity, and mechanisms of action. Ann N Y Acad Sci 2000; 914:369-86. [PMID: 11085336 DOI: 10.1111/j.1749-6632.2000.tb05211.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
18-MC, a novel iboga alkaloid congener, is being developed as a potential treatment for multiple forms of drug abuse. Like ibogaine (40 mg/kg), 18-MC (40 mg/kg) decreases the intravenous self-administration of morphine and cocaine and the oral self-administration of ethanol and nicotine in rats; unlike ibogaine, 18-MC does not affect responding for a nondrug reinforcer (water). Both ibogaine and 18-MC ameliorate opioid withdrawal signs. Both ibogaine and 18-MC decrease extracellular levels of dopamine in the nucleus accumbens, but only ibogaine increases extracellular levels of serotonin in the nucleus accumbens. Both ibogaine and 18-MC block morphine-induced and nicotine-induced dopamine release in the nucleus accumbens; only ibogaine enhances cocaine-induced increases in accumbal dopamine. Both ibogaine and 18-MC enhance the locomotor and/or stereotypic effects of stimulants. Ibogaine attenuates, but 18-MC potentiates, the acute locomotor effects of morphine; both compounds attenuate morphine-induced locomotion in morphine-experienced rats. Ibogaine produces whole body tremors and, at high doses (> or = 100 mg/kg), cerebellar damage; 18-MC does not produce these effects. Ibogaine, but not 18-MC, decreases heart rate at high doses. While 18-MC and ibogaine have similar affinities for kappa opioid and possibly nicotinic receptors, 18-MC has much lower affinities than ibogaine for NMDA and sigma-2 receptors, sodium channels, and the 5-HT transporter. Both 18-MC and ibogaine are sequestered in fat and, like ibogaine, 18-MC probably has an active metabolite. The data suggest that 18-MC has a narrower spectrum of actions and will have a substantially greater therapeutic index than ibogaine.
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Affiliation(s)
- S D Glick
- Department of Pharmacology and Neuroscience, Albany Medical College, New York 12208, USA.
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Glick SD, Maisonneuve IM. Development of novel medications for drug addiction. The legacy of an African shrub. Ann N Y Acad Sci 2000; 909:88-103. [PMID: 10911925 DOI: 10.1111/j.1749-6632.2000.tb06677.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Ibogaine, one of several alkaloids found in the root bark of the African shrub Tabernanthe iboga, has been claimed to be effective in treating multiple forms of drug abuse. Problems associated with side effects of ibogaine have spawned a search for more effective and safer structural derivatives. 18-Methoxycoronaridine (18-MC), a novel iboga alkaloid congener, appears to have substantial potential for broad use as an anti-addictive therapy. Like ibogaine (40 mg/kg), 18-MC (40 mg/kg) decreases the intravenous self-administration of morphine and cocaine and the oral self-administration of ethanol and nicotine in rats; unlike ibogaine, 18-MC does not affect responding for a non-drug reinforcer (water). Ibogaine and 18-MC appear to reduce the reinforcing efficacies, rather than the potencies, of drugs of abuse. Both ibogaine and 18-MC decreases extracellular levels of dopamine in the nucleus accumbens while only ibogaine increases serotonin levels in this brain region. Both ibogaine and 18-MC block morphine-induced and nicotine-induced dopamine release in the accumbens; only ibogaine enhances cocaine-induced increases in dopamine levels. Ibogaine produces whole body tremors and, at high doses (at least 100 mg/kg), cerebellar damage; 18-MC does not produce these effects. Ibogaine, but not 18-MC, causes bradycardia at high doses. Ibogaine and its metabolite noribogaine have low microM affinities for kappa and mu opioid receptors, NMDA receptors, 5HT-3 receptors, sigma-2 sites, sodium channels and the serotonin transporter. 18-MC has low microM affinities at all three opioid receptors and at 5HT-3 receptors but much lower or no affinities for NMDA and sigma-2 receptors, sodium channels, and the 5HT transporter. Both 18-MC and ibogaine are sequestered in fat and, like ibogaine, 18-MC probably has an active metabolite. 18-MC also has (+) and (-) enantiomers, both of which are active. Considered together, all of the data indicate that 18-MC should be safer than ibogaine and at least as efficacious as an anti-addictive medication.
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Affiliation(s)
- S D Glick
- Department of Pharmacology and Neuroscience, Albany Medical College, New York 12208, USA.
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Mundey MK, Blaylock NA, Mason R, Glick SD, Maisonneuve IM, Wilson VG. Pharmacological comparison of the effect of ibogaine and 18-methoxycoronaridine on isolated smooth muscle from the rat and guinea-pig. Br J Pharmacol 2000; 129:1561-8. [PMID: 10780959 PMCID: PMC1571996 DOI: 10.1038/sj.bjp.0703227] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/1999] [Revised: 11/23/1999] [Accepted: 01/10/2000] [Indexed: 11/08/2022] Open
Abstract
Ibogaine and 18-methoxycoronaridine are naturally occurring alkaloids reported to possess antiaddictive properties in several models of drug dependence. We have examined their effect at mu-opioid receptors regulating neurogenic contractions of several smooth muscle preparations and also against spontaneous contractions of the rat isolated portal vein. Ibogaine (pIC(50) 5.28) and 18-methoxycoronaridine (pIC(50) 5.05) caused a concentration-dependent inhibition of cholinergic contractions of the guinea-pig ileum which was not affected by the opioid receptor antagonist naloxone (1 microM). In the rat isolated vas deferens ibogaine and 18-methoxycoronaridine caused a concentration-dependent enhancement of purinergic contractions. Both agents (30 microM) caused a 3 - 5 fold rightward displacement of DAMGO-induced inhibition of purinergic contractions, but similar effects were observed for ibogaine against alpha(2)-adrenoceptor-mediated inhibition of neurogenic responses. In the guinea-pig isolated bladder both ibogaine (10 microM) and 18-methoxycoronaridine (10 microM) caused a 2 fold increase in the purinergic component of neurogenic contractions without significantly altering cholinergic contractions or responses to exogenous ATP. In contrast, ibogaine (1 - 30 microM), but not 18-methoxycoronaridine, caused a concentration-dependent enhancement of spontaneous contractions of the rat isolated portal vein. In summary, while ibogaine and 18-methoxycoronaridine modulated electrically-evoked contractions in the three preparations examined, we have no evidence for a selective interaction with pre-junctional mu-opioid receptors. The pronounced enhancement of purinergic contractions produced by both agents is a novel finding and worthy of further investigation.
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Affiliation(s)
- M K Mundey
- School of Biomedical Sciences, The Medical School, E. Floor, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH
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