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Shegani A, Kealey S, Luzi F, Basagni F, Machado JDM, Ekici SD, Ferocino A, Gee AD, Bongarzone S. Radiosynthesis, Preclinical, and Clinical Positron Emission Tomography Studies of Carbon-11 Labeled Endogenous and Natural Exogenous Compounds. Chem Rev 2022; 123:105-229. [PMID: 36399832 PMCID: PMC9837829 DOI: 10.1021/acs.chemrev.2c00398] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The presence of positron emission tomography (PET) centers at most major hospitals worldwide, along with the improvement of PET scanner sensitivity and the introduction of total body PET systems, has increased the interest in the PET tracer development using the short-lived radionuclides carbon-11. In the last few decades, methodological improvements and fully automated modules have allowed the development of carbon-11 tracers for clinical use. Radiolabeling natural compounds with carbon-11 by substituting one of the backbone carbons with the radionuclide has provided important information on the biochemistry of the authentic compounds and increased the understanding of their in vivo behavior in healthy and diseased states. The number of endogenous and natural compounds essential for human life is staggering, ranging from simple alcohols to vitamins and peptides. This review collates all the carbon-11 radiolabeled endogenous and natural exogenous compounds synthesised to date, including essential information on their radiochemistry methodologies and preclinical and clinical studies in healthy subjects.
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Affiliation(s)
- Antonio Shegani
- School
of Biomedical Engineering & Imaging Sciences, King’s College London, King’s Health Partners, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - Steven Kealey
- School
of Biomedical Engineering & Imaging Sciences, King’s College London, King’s Health Partners, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - Federico Luzi
- School
of Biomedical Engineering & Imaging Sciences, King’s College London, King’s Health Partners, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - Filippo Basagni
- Department
of Pharmacy and Biotechnology, Alma Mater
Studiorum−University of Bologna, via Belmeloro 6, 40126 Bologna, Italy
| | - Joana do Mar Machado
- School
of Biomedical Engineering & Imaging Sciences, King’s College London, King’s Health Partners, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - Sevban Doğan Ekici
- School
of Biomedical Engineering & Imaging Sciences, King’s College London, King’s Health Partners, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - Alessandra Ferocino
- Institute
of Organic Synthesis and Photoreactivity, Italian National Research Council, via Piero Gobetti 101, 40129 Bologna, Italy
| | - Antony D. Gee
- School
of Biomedical Engineering & Imaging Sciences, King’s College London, King’s Health Partners, St Thomas’ Hospital, London SE1 7EH, United Kingdom,A.G.: email,
| | - Salvatore Bongarzone
- School
of Biomedical Engineering & Imaging Sciences, King’s College London, King’s Health Partners, St Thomas’ Hospital, London SE1 7EH, United Kingdom,S.B.:
email,
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2
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Molecular Pathways of the Therapeutic Effects of Ayahuasca, a Botanical Psychedelic and Potential Rapid-Acting Antidepressant. Biomolecules 2022; 12:biom12111618. [DOI: 10.3390/biom12111618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 10/27/2022] [Accepted: 10/29/2022] [Indexed: 11/06/2022] Open
Abstract
Ayahuasca is a psychoactive brew traditionally used in indigenous and religious rituals and ceremonies in South America for its therapeutic, psychedelic, and entheogenic effects. It is usually prepared by lengthy boiling of the leaves of the bush Psychotria viridis and the mashed stalks of the vine Banisteriopsis caapi in water. The former contains the classical psychedelic N,N-dimethyltryptamine (DMT), which is thought to be the main psychoactive alkaloid present in the brew. The latter serves as a source for β-carbolines, known for their monoamine oxidase-inhibiting (MAOI) properties. Recent preliminary research has provided encouraging results investigating ayahuasca’s therapeutic potential, especially regarding its antidepressant effects. On a molecular level, pre-clinical and clinical evidence points to a complex pharmacological profile conveyed by the brew, including modulation of serotoninergic, glutamatergic, dopaminergic, and endocannabinoid systems. Its substances also interact with the vesicular monoamine transporter (VMAT), trace amine-associated receptor 1 (TAAR1), and sigma-1 receptors. Furthermore, ayahuasca’s components also seem to modulate levels of inflammatory and neurotrophic factors beneficially. On a biological level, this translates into neuroprotective and neuroplastic effects. Here we review the current knowledge regarding these molecular interactions and how they relate to the possible antidepressant effects ayahuasca seems to produce.
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Abstract
N,N-dimethyltryptamine (DMT) is a potent psychedelic naturally produced by many plants and animals, including humans. Whether or not DMT is significant to mammalian physiology, especially within the central nervous system, is a debate that started in the early 1960s and continues to this day. This review integrates historical and recent literature to clarify this issue, giving special attention to the most controversial subjects of DMT's biosynthesis, its storage in synaptic vesicles and the activation receptors like sigma-1. Less discussed topics, like DMT's metabolic regulation or the biased activation of serotonin receptors, are highlighted. We conclude that most of the arguments dismissing endogenous DMT's relevance are based on obsolete data or misleading assumptions. Data strongly suggest that DMT can be relevant as a neurotransmitter, neuromodulator, hormone and immunomodulator, as well as being important to pregnancy and development. Key experiments are addressed to definitely prove what specific roles DMT plays in mammalian physiology.
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Affiliation(s)
- Javier Hidalgo Jiménez
- ICEERS Foundation (International Center for Ethnobotanical Education, Research and Services), Barcelona, Spain
| | - José Carlos Bouso
- ICEERS Foundation (International Center for Ethnobotanical Education, Research and Services), Barcelona, Spain
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4
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Glavonic E, Mitic M, Adzic M. Hallucinogenic drugs and their potential for treating fear-related disorders: Through the lens of fear extinction. J Neurosci Res 2022; 100:947-969. [PMID: 35165930 DOI: 10.1002/jnr.25017] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 12/17/2021] [Accepted: 01/05/2022] [Indexed: 12/29/2022]
Abstract
Fear-related disorders, mainly phobias and post-traumatic stress disorder, are highly prevalent, debilitating disorders that pose a significant public health problem. They are characterized by aberrant processing of aversive experiences and dysregulated fear extinction, leading to excessive expression of fear and diminished quality of life. The gold standard for treating fear-related disorders is extinction-based exposure therapy (ET), shown to be ineffective for up to 35% of subjects. Moreover, ET combined with traditional pharmacological treatments for fear-related disorders, such as selective serotonin reuptake inhibitors, offers no further advantage to patients. This prompted the search for ways to improve ET outcomes, with current research focused on pharmacological agents that can augment ET by strengthening fear extinction learning. Hallucinogenic drugs promote reprocessing of fear-imbued memories and induce positive mood and openness, relieving anxiety and enabling the necessary emotional engagement during psychotherapeutic interventions. Mechanistically, hallucinogens induce dynamic structural and functional neuroplastic changes across the fear extinction circuitry and temper amygdala's hyperreactivity to threat-related stimuli, effectively mitigating one of the hallmarks of fear-related disorders. This paper provides the first comprehensive review of hallucinogens' potential to alleviate symptoms of fear-related disorders by focusing on their effects on fear extinction and the underlying molecular mechanisms. We overview both preclinical and clinical studies and emphasize the advantages of hallucinogenic drugs over current first-line treatments. We highlight 3,4-methylenedioxymethamphetamine and ketamine as the most effective therapeutics for fear-related disorders and discuss the potential molecular mechanisms responsible for their potency with implications for improving hallucinogen-assisted psychotherapy.
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Affiliation(s)
- Emilija Glavonic
- Department of Molecular Biology and Endocrinology, "VINČA" Institute of Nuclear Sciences-National Institute of thе Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Milos Mitic
- Department of Molecular Biology and Endocrinology, "VINČA" Institute of Nuclear Sciences-National Institute of thе Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Miroslav Adzic
- Department of Molecular Biology and Endocrinology, "VINČA" Institute of Nuclear Sciences-National Institute of thе Republic of Serbia, University of Belgrade, Belgrade, Serbia
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5
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Szabó Í, Varga VÉ, Dvorácskó S, Farkas AE, Körmöczi T, Berkecz R, Kecskés S, Menyhárt Á, Frank R, Hantosi D, Cozzi NV, Frecska E, Tömböly C, Krizbai IA, Bari F, Farkas E. N,N-Dimethyltryptamine attenuates spreading depolarization and restrains neurodegeneration by sigma-1 receptor activation in the ischemic rat brain. Neuropharmacology 2021; 192:108612. [PMID: 34023338 DOI: 10.1016/j.neuropharm.2021.108612] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 04/23/2021] [Accepted: 05/13/2021] [Indexed: 12/19/2022]
Abstract
Dimethyltryptamine (DMT), an endogenous ligand of sigma-1 receptors (Sig-1Rs), acts against systemic hypoxia, but whether DMT may prevent cerebral ischemic injury is unexplored. Here global forebrain ischemia was created in anesthetized rats and aggravated with the induction of spreading depolarizations (SDs) and subsequent short hypoxia before reperfusion. Drugs (DMT, the selective Sig-1R agonist PRE-084, the Sig-1R antagonist NE-100, or the serotonin receptor antagonist asenapine) were administered intravenously alone or in combination while physiological variables and local field potential from the cerebral cortex was recorded. Neuroprotection and the cellular localization of Sig-1R were evaluated with immunocytochemistry. Plasma and brain DMT content was measured by 2D-LC-HRMS/MS. The affinity of drugs for cerebral Sig-1R was evaluated with a radioligand binding assay. Both DMT and PRE-084 mitigated SDs, counteracted with NE-100. Further, DMT attenuated SD when co-administered with asenapine, compared to asenapine alone. DMT reduced the number of apoptotic and ferroptotic cells and supported astrocyte survival. The binding affinity of DMT to Sig-1R matched previously reported values. Sig-1Rs were associated with the perinuclear cytoplasm of neurons, astrocytes and microglia, and with glial processes. According to these data, DMT may be considered as adjuvant pharmacological therapy in the management of acute cerebral ischemia.
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Affiliation(s)
- Írisz Szabó
- Department of Medical Physics and Informatics, Faculty of Medicine and Faculty of Science and Informatics, University of Szeged; Korányi Fasor 9, Szeged, 6720, Hungary.
| | - Viktória É Varga
- Department of Medical Physics and Informatics, Faculty of Medicine and Faculty of Science and Informatics, University of Szeged; Korányi Fasor 9, Szeged, 6720, Hungary.
| | - Szabolcs Dvorácskó
- Laboratory of Chemical Biology, Institute of Biochemistry, Biological Research Centre, Temesvári Krt 62, Szeged, 6726, Hungary; Department of Medical Chemistry, Faculty of Medicine, University of Szeged, Dóm Tér 8, Szeged, 6720, Hungary.
| | - Attila E Farkas
- Neurovascular Unit Research Group, Molecular Neurobiology Research Unit, Institute of Biophysics, Biological Research Centre, Temesvári Krt 62, Szeged, 6726, Hungary.
| | - Tímea Körmöczi
- Department of Medical Chemistry, Faculty of Medicine, University of Szeged, Dóm Tér 8, Szeged, 6720, Hungary; Institute of Pharmaceutical Analysis, Faculty of Pharmacy, University of Szeged, Somogyi U 4, Szeged, 6720, Hungary.
| | - Róbert Berkecz
- Department of Medical Chemistry, Faculty of Medicine, University of Szeged, Dóm Tér 8, Szeged, 6720, Hungary; Institute of Pharmaceutical Analysis, Faculty of Pharmacy, University of Szeged, Somogyi U 4, Szeged, 6720, Hungary.
| | - Szilvia Kecskés
- Department of Medical Physics and Informatics, Faculty of Medicine and Faculty of Science and Informatics, University of Szeged; Korányi Fasor 9, Szeged, 6720, Hungary.
| | - Ákos Menyhárt
- Department of Medical Physics and Informatics, Faculty of Medicine and Faculty of Science and Informatics, University of Szeged; Korányi Fasor 9, Szeged, 6720, Hungary.
| | - Rita Frank
- Department of Medical Physics and Informatics, Faculty of Medicine and Faculty of Science and Informatics, University of Szeged; Korányi Fasor 9, Szeged, 6720, Hungary.
| | - Dóra Hantosi
- Department of Medical Physics and Informatics, Faculty of Medicine and Faculty of Science and Informatics, University of Szeged; Korányi Fasor 9, Szeged, 6720, Hungary.
| | - Nicholas V Cozzi
- Neuropharmacology Laboratory, University of Wisconsin School of Medicine and Public Health, 1300 University Avenue, Madison, WI 53706, USA; Alexander Shulgin Research Institute, 1483 Shulgin Road, Lafayette, CA, 94549, USA.
| | - Ede Frecska
- Department of Psychiatry, Faculty of Medicine, University of Debrecen, Nagyerdei Krt 94, Debrecen, 4032, Hungary.
| | - Csaba Tömböly
- Laboratory of Chemical Biology, Institute of Biochemistry, Biological Research Centre, Temesvári Krt 62, Szeged, 6726, Hungary.
| | - István A Krizbai
- Neurovascular Unit Research Group, Molecular Neurobiology Research Unit, Institute of Biophysics, Biological Research Centre, Temesvári Krt 62, Szeged, 6726, Hungary; Institute of Life Sciences, UVVG, 94 Bulevardul Revoluției, Arad, 310025, Romania.
| | - Ferenc Bari
- Department of Medical Physics and Informatics, Faculty of Medicine and Faculty of Science and Informatics, University of Szeged; Korányi Fasor 9, Szeged, 6720, Hungary.
| | - Eszter Farkas
- Department of Medical Physics and Informatics, Faculty of Medicine and Faculty of Science and Informatics, University of Szeged; Korányi Fasor 9, Szeged, 6720, Hungary.
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6
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Klein AK, Chatha M, Laskowski LJ, Anderson EI, Brandt SD, Chapman SJ, McCorvy JD, Halberstadt AL. Investigation of the Structure-Activity Relationships of Psilocybin Analogues. ACS Pharmacol Transl Sci 2020; 4:533-542. [PMID: 33860183 DOI: 10.1021/acsptsci.0c00176] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Indexed: 12/19/2022]
Abstract
The 5-HT2A receptor is thought to be the primary target for psilocybin (4-phosphoryloxy-N,N-dimethyltryptamine) and other serotonergic hallucinogens (psychedelic drugs). Although a large amount of experimental work has been conducted to characterize the pharmacology of psilocybin and its dephosphorylated metabolite psilocin (4-hydroxy-N,N-dimethyltryptamine), there has been little systematic investigation of the structure-activity relationships (SAR) of 4-substituted tryptamine derivatives. In addition, structural analogs of psilocybin containing a 4-acetoxy group, such as 4-acetoxy-N,N-dimethyltryptamine (4-AcO-DMT), have appeared as new designer drugs, but almost nothing is known about their pharmacological effects. To address the gap of information, studies were conducted with 17 tryptamines containing a variety of symmetrical and asymmetrical N,N-dialkyl substituents and either a 4-hydroxy or 4-acetoxy group. Calcium mobilization assays were conducted to assess functional activity at human and mouse 5-HT2 subtypes. Head-twitch response (HTR) studies were conducted in C57BL/6J mice to assess 5-HT2A activation in vivo. All of the compounds acted as full or partial agonists at 5-HT2 subtypes, displaying similar potencies at 5-HT2A and 5-HT2B receptors, but some tryptamines with bulkier N-alkyl groups had lower potency at 5-HT2C receptors and higher 5-HT2B receptor efficacy. In addition, O-acetylation reduced the in vitro 5-HT2A potency of 4-hydroxy-N,N-dialkyltryptamines by about 10- to 20-fold but did not alter agonist efficacy. All of the compounds induce head twitches in mice, consistent with an LSD-like behavioral profile. In contrast to the functional data, acetylation of the 4-hydroxy group had little effect on HTR potency, suggesting that O-acetylated tryptamines may be deacetylated in vivo, acting as prodrugs. In summary, the tryptamine derivatives have psilocybin-like pharmacological properties, supporting their classification as psychedelic drugs.
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Affiliation(s)
- Adam K Klein
- Department of Psychiatry, University of California San Diego, La Jolla, California 92093-0804, United States
| | - Muhammad Chatha
- Department of Psychiatry, University of California San Diego, La Jolla, California 92093-0804, United States
| | - Lauren J Laskowski
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin 53226-0509, United States
| | - Emilie I Anderson
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin 53226-0509, United States
| | - Simon D Brandt
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, United Kingdom
| | | | - John D McCorvy
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin 53226-0509, United States
| | - Adam L Halberstadt
- Department of Psychiatry, University of California San Diego, La Jolla, California 92093-0804, United States.,Research Service, VA San Diego Healthcare System, San Diego, California 92161, United States
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7
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Brito-da-Costa AM, Dias-da-Silva D, Gomes NGM, Dinis-Oliveira RJ, Madureira-Carvalho Á. Toxicokinetics and Toxicodynamics of Ayahuasca Alkaloids N, N-Dimethyltryptamine (DMT), Harmine, Harmaline and Tetrahydroharmine: Clinical and Forensic Impact. Pharmaceuticals (Basel) 2020; 13:ph13110334. [PMID: 33114119 PMCID: PMC7690791 DOI: 10.3390/ph13110334] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 10/16/2020] [Accepted: 10/20/2020] [Indexed: 12/11/2022] Open
Abstract
Ayahuasca is a hallucinogenic botanical beverage originally used by indigenous Amazonian tribes in religious ceremonies and therapeutic practices. While ethnobotanical surveys still indicate its spiritual and medicinal uses, consumption of ayahuasca has been progressively related with a recreational purpose, particularly in Western societies. The ayahuasca aqueous concoction is typically prepared from the leaves of the N,N-dimethyltryptamine (DMT)-containing Psychotria viridis, and the stem and bark of Banisteriopsis caapi, the plant source of harmala alkaloids. Herein, the toxicokinetics and toxicodynamics of the psychoactive DMT and harmala alkaloids harmine, harmaline and tetrahydroharmine, are comprehensively covered, particularly emphasizing the psychological, physiological, and toxic effects deriving from their concomitant intake. Potential therapeutic utility, particularly in mental and psychiatric disorders, and forensic aspects of DMT and ayahuasca are also reviewed and discussed. Following administration of ayahuasca, DMT is rapidly absorbed and distributed. Harmala alkaloids act as potent inhibitors of monoamine oxidase A (MAO-A), preventing extensive first-pass degradation of DMT into 3-indole-acetic acid (3-IAA), and enabling sufficient amounts of DMT to reach the brain. DMT has affinity for a variety of serotonergic and non-serotonergic receptors, though its psychotropic effects are mainly related with the activation of serotonin receptors type 2A (5-HT2A). Mildly to rarely severe psychedelic adverse effects are reported for ayahuasca or its alkaloids individually, but abuse does not lead to dependence or tolerance. For a long time, the evidence has pointed to potential psychotherapeutic benefits in the treatment of depression, anxiety, and substance abuse disorders; and although misuse of ayahuasca has been diverting attention away from such clinical potential, research onto its therapeutic effects has now strongly resurged.
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Affiliation(s)
- Andreia Machado Brito-da-Costa
- Department of Sciences, IINFACTS-Institute of Research and Advanced Training in Health Sciences and Technologies, University Institute of Health Sciences (IUCS), CESPU, CRL, 4585-116 Gandra, Portugal; (A.M.B.-d.-C.); (N.G.M.G.); (Á.M.-C.)
| | - Diana Dias-da-Silva
- Department of Sciences, IINFACTS-Institute of Research and Advanced Training in Health Sciences and Technologies, University Institute of Health Sciences (IUCS), CESPU, CRL, 4585-116 Gandra, Portugal; (A.M.B.-d.-C.); (N.G.M.G.); (Á.M.-C.)
- UCIBIO-REQUIMTE, Laboratory of Toxicology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, 4050-313 Porto, Portugal
- Correspondence: (D.D.-d.-S.); (R.J.D.-O.); Tel.: +351-224-157-216 (R.J.D.-O.)
| | - Nelson G. M. Gomes
- Department of Sciences, IINFACTS-Institute of Research and Advanced Training in Health Sciences and Technologies, University Institute of Health Sciences (IUCS), CESPU, CRL, 4585-116 Gandra, Portugal; (A.M.B.-d.-C.); (N.G.M.G.); (Á.M.-C.)
- LAQV-REQUIMTE, Laboratory of Pharmacognosy, Department of Chemistry, Faculty of Pharmacy, University of Porto, 4050-313 Porto, Portugal
| | - Ricardo Jorge Dinis-Oliveira
- Department of Sciences, IINFACTS-Institute of Research and Advanced Training in Health Sciences and Technologies, University Institute of Health Sciences (IUCS), CESPU, CRL, 4585-116 Gandra, Portugal; (A.M.B.-d.-C.); (N.G.M.G.); (Á.M.-C.)
- UCIBIO-REQUIMTE, Laboratory of Toxicology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, 4050-313 Porto, Portugal
- Department of Public Health and Forensic Sciences, and Medical Education, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal
- Correspondence: (D.D.-d.-S.); (R.J.D.-O.); Tel.: +351-224-157-216 (R.J.D.-O.)
| | - Áurea Madureira-Carvalho
- Department of Sciences, IINFACTS-Institute of Research and Advanced Training in Health Sciences and Technologies, University Institute of Health Sciences (IUCS), CESPU, CRL, 4585-116 Gandra, Portugal; (A.M.B.-d.-C.); (N.G.M.G.); (Á.M.-C.)
- LAQV-REQUIMTE, Laboratory of Pharmacognosy, Department of Chemistry, Faculty of Pharmacy, University of Porto, 4050-313 Porto, Portugal
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8
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Ly C, Greb AC, Vargas MV, Duim WC, Grodzki ACG, Lein PJ, Olson DE. Transient Stimulation with Psychoplastogens Is Sufficient to Initiate Neuronal Growth. ACS Pharmacol Transl Sci 2020; 4:452-460. [PMID: 33860174 DOI: 10.1021/acsptsci.0c00065] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Indexed: 12/16/2022]
Abstract
Cortical neuron atrophy is a hallmark of depression and includes neurite retraction, dendritic spine loss, and decreased synaptic density. Psychoplastogens, small molecules capable of rapidly promoting cortical neuron growth, have been hypothesized to produce long-lasting positive effects on behavior by rectifying these deleterious structural and functional changes. Here we demonstrate that ketamine and LSD, psychoplastogens from two structurally distinct chemical classes, promote sustained growth of cortical neurons after only short periods of stimulation. Furthermore, we show that psychoplastogen-induced cortical neuron growth can be divided into two distinct epochs: an initial stimulation phase requiring TrkB activation and a growth period involving sustained mTOR and AMPA receptor activation. Our results provide important temporal details concerning the molecular mechanisms by which next-generation antidepressants produce persistent changes in cortical neuron structure, and they suggest that rapidly excreted psychoplastogens might still be effective neurotherapeutics with unique advantages over compounds like ketamine and LSD.
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Affiliation(s)
- Calvin Ly
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California, Davis 95616, United States
| | - Alexandra C Greb
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California, Davis 95616, United States
| | - Maxemiliano V Vargas
- Neuroscience Graduate Program, University of California, Davis, Davis, California 95618, United States
| | - Whitney C Duim
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California, Davis 95616, United States
| | - Ana Cristina G Grodzki
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, 1089 Veterinary Medicine Drive, Davis, California 95616, United States
| | - Pamela J Lein
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, 1089 Veterinary Medicine Drive, Davis, California 95616, United States
| | - David E Olson
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California, Davis 95616, United States.,Department of Biochemistry & Molecular Medicine, School of Medicine, University of California, Davis, 2700 Stockton Boulevard, Suite 2102, Sacramento, California 95817, United States.,Center for Neuroscience, University of California, Davis, 1544 Newton Ct, Davis, California 95618, United States
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9
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Rodrigues AVSL, Almeida FJ, Vieira-Coelho MA. Dimethyltryptamine: Endogenous Role and Therapeutic Potential. J Psychoactive Drugs 2019; 51:299-310. [DOI: 10.1080/02791072.2019.1602291] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Alexandra VSL Rodrigues
- Department of Biomedicine-Pharmacology and Therapeutics unit, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Francisco Jcg Almeida
- Department of Biomedicine-Pharmacology and Therapeutics unit, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Maria A Vieira-Coelho
- Department of Biomedicine-Pharmacology and Therapeutics unit, Faculty of Medicine, University of Porto, Porto, Portugal
- Psychiatry and Mental Health Clinic, Hospital de São João, Porto, Portugal
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10
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Cameron LP, Olson DE. Dark Classics in Chemical Neuroscience: N, N-Dimethyltryptamine (DMT). ACS Chem Neurosci 2018; 9:2344-2357. [PMID: 30036036 DOI: 10.1021/acschemneuro.8b00101] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Though relatively obscure, N, N-dimethyltryptamine (DMT) is an important molecule in psychopharmacology as it is the archetype for all indole-containing serotonergic psychedelics. Its structure can be found embedded within those of better-known molecules such as lysergic acid diethylamide (LSD) and psilocybin. Unlike the latter two compounds, DMT is ubiquitous, being produced by a wide variety of plant and animal species. It is one of the principal psychoactive components of ayahuasca, a tisane made from various plant sources that has been used for centuries. Furthermore, DMT is one of the few psychedelic compounds produced endogenously by mammals, and its biological function in human physiology remains a mystery. In this review, we cover the synthesis of DMT as well as its pharmacology, metabolism, adverse effects, and potential use in medicine. Finally, we discuss the history of DMT in chemical neuroscience and why this underappreciated molecule is so important to the field of psychedelic science.
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Affiliation(s)
- Lindsay P. Cameron
- Neuroscience Graduate Program, University of California, Davis, 1544 Newton Ct., Davis, California 95618, United States
| | - David E. Olson
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
- Department of Biochemistry & Molecular Medicine, School of Medicine, University of California, Davis, 2700 Stockton Blvd., Suite 2102, Sacramento, California 95817, United States
- Center for Neuroscience, University of California, Davis, 1544 Newton Ct., Davis, California 95618, United States
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11
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Dean JG. Indolethylamine- N-methyltransferase Polymorphisms: Genetic and Biochemical Approaches for Study of Endogenous N,N,-dimethyltryptamine. Front Neurosci 2018; 12:232. [PMID: 29740267 PMCID: PMC5924808 DOI: 10.3389/fnins.2018.00232] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 03/23/2018] [Indexed: 12/05/2022] Open
Abstract
N,N-dimethyltryptamine (DMT) is a powerful serotonergic psychedelic whose exogenous administration elicits striking psychedelic effects in humans. Studies have identified DMT and analogous compounds (e.g., 5-hydroxy-DMT, 5-methoxy-DMT) alongside of an enzyme capable of synthesizing DMT endogenously from tryptamine, indolethylamine-N-methyltransferase (INMT), in human and several other mammalian tissues. Subsequently, multiple hypotheses for the physiological role of endogenous DMT have emerged, from proposed immunomodulatory functions to an emphasis on the overlap between the mental states generated by exogenous DMT and naturally occurring altered states of consciousness; e.g., schizophrenia. However, no clear relationship between endogenous DMT and naturally occurring altered states of consciousness has yet been established from in vivo assays of DMT in bodily fluids. The advent of genetic screening has afforded the capability to link alterations in the sequence of specific genes to behavioral and molecular phenotypes via expression of identified single nucleotide polymorphisms (SNPs) in cell and animal models. As SNPs in INMT may impact endogenous DMT synthesis and levels via changes in INMT expression and/or INMT structure and function, these combined genetic and biochemical approaches circumvent the limitations of assaying DMT in bodily fluids and may augment data from prior in vitro and in vivo work. Therefore, all reported SNPs in INMT were amassed from genetic and biochemical literature and genomic databases to consolidate a blueprint for future studies aimed at elucidating whether DMT plays a physiological role.
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Affiliation(s)
- Jon G Dean
- Molecular and Integrative Physiology, Center for Consciousness Science, University of Michigan, Ann Arbor, MI, United States
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Abstract
The pineal gland has a romantic history, from pharaonic Egypt, where it was equated with the eye of Horus, through various religious traditions, where it was considered the seat of the soul, the third eye, etc. Recent incarnations of these notions have suggested that N,N-dimethyltryptamine is secreted by the pineal gland at birth, during dreaming, and at near death to produce out of body experiences. Scientific evidence, however, is not consistent with these ideas. The adult pineal gland weighs less than 0.2 g, and its principal function is to produce about 30 µg per day of melatonin, a hormone that regulates circadian rhythm through very high affinity interactions with melatonin receptors. It is clear that very minute concentrations of N,N-dimethyltryptamine have been detected in the brain, but they are not sufficient to produce psychoactive effects. Alternative explanations are presented to explain how stress and near death can produce altered states of consciousness without invoking the intermediacy of N,N-dimethyltryptamine.
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Carbonaro TM, Gatch MB. Neuropharmacology of N,N-dimethyltryptamine. Brain Res Bull 2016; 126:74-88. [PMID: 27126737 PMCID: PMC5048497 DOI: 10.1016/j.brainresbull.2016.04.016] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 04/21/2016] [Accepted: 04/22/2016] [Indexed: 12/20/2022]
Abstract
N,N-dimethyltryptamine (DMT) is an indole alkaloid widely found in plants and animals. It is best known for producing brief and intense psychedelic effects when ingested. Increasing evidence suggests that endogenous DMT plays important roles for a number of processes in the periphery and central nervous system, and may act as a neurotransmitter. This paper reviews the current literature of both the recreational use of DMT and its potential roles as an endogenous neurotransmitter. Pharmacokinetics, mechanisms of action in the periphery and central nervous system, clinical uses and adverse effects are also reviewed. DMT appears to have limited neurotoxicity and other adverse effects except for intense cardiovascular effects when administered intravenously in large doses. Because of its role in nervous system signaling, DMT may be a useful experimental tool in exploring how the brain works, and may also be a useful clinical tool for treatment of anxiety and psychosis.
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Affiliation(s)
- Theresa M Carbonaro
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Michael B Gatch
- Center for Neuroscience Discovery University of North Texas Health Science Center Fort Worth, TX, United States.
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Gallimore AR, Strassman RJ. A Model for the Application of Target-Controlled Intravenous Infusion for a Prolonged Immersive DMT Psychedelic Experience. Front Pharmacol 2016; 7:211. [PMID: 27471468 PMCID: PMC4944667 DOI: 10.3389/fphar.2016.00211] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 06/30/2016] [Indexed: 01/22/2023] Open
Abstract
The state of consciousness induced by N,N-dimethyltryptamine (DMT) is one of the most extraordinary of any naturally-occurring psychedelic substance. Users consistently report the complete replacement of normal subjective experience with a novel "alternate universe," often densely populated with a variety of strange objects and other highly complex visual content, including what appear to be sentient "beings." The phenomenology of the DMT state is of great interest to psychology and calls for rigorous academic enquiry. The extremely short duration of DMT effects-less than 20 min-militates against single dose administration as the ideal model for such enquiry. Using pharmacokinetic modeling and DMT blood sampling data, we demonstrate that the unique pharmacological characteristics of DMT, which also include a rapid onset and lack of acute tolerance to its subjective effects, make it amenable to administration by target-controlled intravenous infusion. This is a technology developed to maintain a stable brain concentration of anesthetic drugs during surgery. Simulations of our model demonstrate that this approach will allow research subjects to be induced into a stable and prolonged DMT experience, making it possible to carefully observe its psychological contents, and provide more extensive accounts for subsequent analyses. This model would also be valuable in performing functional neuroimaging, where subjects are required to remain under the influence of the drug for extended periods. Finally, target-controlled intravenous infusion of DMT may aid the development of unique psychotherapeutic applications of this psychedelic agent.
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Affiliation(s)
- Andrew R. Gallimore
- Computational Neuroscience Unit, Okinawa Institute of Science and Technology Graduate UniversityOkinawa, Japan
| | - Rick J. Strassman
- Department of Psychiatry, University of New Mexico School of MedicineAlbuquerque, NM, USA
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Frecska E, Szabo A, Winkelman MJ, Luna LE, McKenna DJ. A possibly sigma-1 receptor mediated role of dimethyltryptamine in tissue protection, regeneration, and immunity. J Neural Transm (Vienna) 2013; 120:1295-303. [PMID: 23619992 DOI: 10.1007/s00702-013-1024-y] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Accepted: 04/01/2013] [Indexed: 01/20/2023]
Abstract
N,N-dimethyltryptamine (DMT) is classified as a naturally occurring serotonergic hallucinogen of plant origin. It has also been found in animal tissues and regarded as an endogenous trace amine transmitter. The vast majority of research on DMT has targeted its psychotropic/psychedelic properties with less focus on its effects beyond the nervous system. The recent discovery that DMT is an endogenous ligand of the sigma-1 receptor may shed light on yet undiscovered physiological mechanisms of DMT activity and reveal some of its putative biological functions. A three-step active uptake process of DMT from peripheral sources to neurons underscores a presumed physiological significance of this endogenous hallucinogen. In this paper, we overview the literature on the effects of sigma-1 receptor ligands on cellular bioenergetics, the role of serotonin, and serotoninergic analogues in immunoregulation and the data regarding gene expression of the DMT synthesizing enzyme indolethylamine-N-methyltransferase in carcinogenesis. We conclude that the function of DMT may extend central nervous activity and involve a more universal role in cellular protective mechanisms. Suggestions are offered for future directions of indole alkaloid research in the general medical field. We provide converging evidence that while DMT is a substance which produces powerful psychedelic experiences, it is better understood not as a hallucinogenic drug of abuse, but rather an agent of significant adaptive mechanisms that can also serve as a promising tool in the development of future medical therapies.
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Affiliation(s)
- Ede Frecska
- Department of Psychiatry, Medical and Health Science Center, University of Debrecen, Nagyerdei krt. 98, 4012, Debrecen, Hungary.
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Dimethyltryptamine and other hallucinogenic tryptamines exhibit substrate behavior at the serotonin uptake transporter and the vesicle monoamine transporter. J Neural Transm (Vienna) 2009; 116:1591-9. [PMID: 19756361 DOI: 10.1007/s00702-009-0308-8] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2009] [Accepted: 08/24/2009] [Indexed: 10/20/2022]
Abstract
N,N-dimethyltryptamine (DMT) is a potent plant hallucinogen that has also been found in human tissues. When ingested, DMT and related N,N-dialkyltryptamines produce an intense hallucinogenic state. Behavioral effects are mediated through various neurochemical mechanisms including activity at sigma-1 and serotonin receptors, modification of monoamine uptake and release, and competition for metabolic enzymes. To further clarify the pharmacology of hallucinogenic tryptamines, we synthesized DMT, N-methyl-N-isopropyltryptamine (MIPT), N,N-dipropyltryptamine (DPT), and N,N-diisopropyltryptamine. We then tested the abilities of these N,N-dialkyltryptamines to inhibit [(3)H]5-HT uptake via the plasma membrane serotonin transporter (SERT) in human platelets and via the vesicle monoamine transporter (VMAT2) in Sf9 cells expressing the rat VMAT2. The tryptamines were also tested as inhibitors of [(3)H]paroxetine binding to the SERT and [(3)H]dihydrotetrabenazine binding to VMAT2. Our results show that DMT, MIPT, DPT, and DIPT inhibit [(3)H]5-HT transport at the SERT with K ( I ) values of 4.00 +/- 0.70, 8.88 +/- 4.7, 0.594 +/- 0.12, and 2.32 +/- 0.46 microM, respectively. At VMAT2, the tryptamines inhibited [(3)H]5-HT transport with K ( I ) values of 93 +/- 6.8, 20 +/- 4.3, 19 +/- 2.3, and 19 +/- 3.1 muM, respectively. On the other hand, the tryptamines were very poor inhibitors of [(3)H]paroxetine binding to SERT and of [(3)H]dihydrotetrabenazine binding to VMAT2, resulting in high binding-to-uptake ratios. High binding-to-uptake ratios support the hypothesis that the tryptamines are transporter substrates, not uptake blockers, at both SERT and VMAT2, and also indicate that there are separate substrate and inhibitor binding sites within these transporters. The transporters may allow the accumulation of tryptamines within neurons to reach relatively high levels for sigma-1 receptor activation and to function as releasable transmitters.
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