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Urbina F, Jones T, Harris JS, Snyder SH, Lane TR, Ekins S. Predicting the Hallucinogenic Potential of Molecules Using Artificial Intelligence. ACS Chem Neurosci 2024; 15:3078-3089. [PMID: 39092989 PMCID: PMC11338697 DOI: 10.1021/acschemneuro.4c00405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/04/2024] Open
Abstract
The development of new drugs addressing serious mental health and other disorders should avoid the psychedelic experience. Analogs of psychedelic drugs can have clinical utility and are termed "psychoplastogens". These represent promising candidates for treating opioid use disorder to reduce drug dependence, with rarely reported serious adverse effects. This drug abuse cessation is linked to the induction of neuritogenesis and increased neuroplasticity, a hallmark of psychedelic molecules, such as lysergic acid diethylamine. Some, but not all psychoplastogens may act through the G-protein coupled receptor (GPCR) 5HT2A whereas others may display very different polypharmacology making prediction of hallucinogenic potential challenging. In the process of developing tools to help design new psychoplastogens, we have used artificial intelligence in the form of machine learning classification models for predicting psychedelic effects using a published in vitro data set from PsychLight (support vector classification (SVC), area under the curve (AUC) 0.74) and in vivo human data derived from books from Shulgin and Shulgin (SVC, AUC, 0.72) with nested five-fold cross validation. We have also explored conformal predictors with ECFP6 and electrostatic descriptors in an effort to optimize them. These models have been used to predict known 5HT2A agonists to assess their potential to act as psychedelics and induce hallucinations for PsychLight (SVC, AUC 0.97) and Shulgin and Shulgin (random forest, AUC 0.71). We have tested these models with head twitch data from the mouse. This predictive capability is desirable to reliably design new psychoplastogens that lack in vivo hallucinogenic potential and help assess existing and future molecules for this potential. These efforts also provide useful insights into understanding the psychedelic structure activity relationship.
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Affiliation(s)
- Fabio Urbina
- Collaborations Pharmaceuticals, Inc., 840 Main Campus Drive, Lab 3510, Raleigh, NC 27606, USA
| | - Thane Jones
- Collaborations Pharmaceuticals, Inc., 840 Main Campus Drive, Lab 3510, Raleigh, NC 27606, USA
| | - Joshua S. Harris
- Collaborations Pharmaceuticals, Inc., 840 Main Campus Drive, Lab 3510, Raleigh, NC 27606, USA
| | - Scott H. Snyder
- Collaborations Pharmaceuticals, Inc., 840 Main Campus Drive, Lab 3510, Raleigh, NC 27606, USA
| | - Thomas R. Lane
- Collaborations Pharmaceuticals, Inc., 840 Main Campus Drive, Lab 3510, Raleigh, NC 27606, USA
| | - Sean Ekins
- Collaborations Pharmaceuticals, Inc., 840 Main Campus Drive, Lab 3510, Raleigh, NC 27606, USA
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Tagen M, Mantuani D, van Heerden L, Holstein A, Klumpers LE, Knowles R. The risk of chronic psychedelic and MDMA microdosing for valvular heart disease. J Psychopharmacol 2023; 37:876-890. [PMID: 37572027 DOI: 10.1177/02698811231190865] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/14/2023]
Abstract
Psychedelic microdosing is the practice of taking very low doses of psychedelic substances, typically over a longer period of time. The long-term safety of chronic microdosing is relatively uncharacterized, but valvular heart disease (VHD) has been proposed as a potential risk due to activation of the serotonin 5-HT2B receptor. However, this risk has not yet been comprehensively assessed. This analysis searched for all relevant in vitro, animal, and clinical studies related to the VHD risk of lysergic acid diethylamide (LSD), psilocybin, mescaline, N,N-dimethyltryptamine (DMT), and the non-psychedelic 3,4-methylenedioxymethamphetamine (MDMA). All five compounds and some metabolites could bind to the 5-HT2B receptor with potency equal to or greater than that of the 5-HT2A receptor, the primary target of psychedelics. All compounds were partial agonists at the 5-HT2B receptor with the exception of mescaline, which could not be adequately assessed due to low potency. Safety margins relative to the maximum plasma concentrations from typical microdoses were greater than known valvulopathogens, but not without potential risk. No animal or clinical studies appropriately designed to evaluate VHD risk were found for the four psychedelics. However, there is some clinical evidence that chronic ingestion of full doses of MDMA is associated with VHD. We conclude that VHD is a potential risk with chronic psychedelic microdosing, but further studies are necessary to better define this risk.
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Affiliation(s)
| | - Daniel Mantuani
- Delos Psyche Research Group, Mountain View, CA, USA
- Delos Therapeutics, Mountain View, CA, USA
| | - Liron van Heerden
- Delos Psyche Research Group, Mountain View, CA, USA
- Delos Therapeutics, Mountain View, CA, USA
| | - Alex Holstein
- Delos Psyche Research Group, Mountain View, CA, USA
- Delos Therapeutics, Mountain View, CA, USA
| | - Linda E Klumpers
- Verdient Science LLC, Englewood, CO, USA
- Larner College of Medicine, University of Vermont, Burlington, Vermont, USA
| | - Richard Knowles
- Delos Psyche Research Group, Mountain View, CA, USA
- Delos Therapeutics, Mountain View, CA, USA
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Sadee W. Ligand-Free Signaling of G-Protein-Coupled Receptors: Physiology, Pharmacology, and Genetics. Molecules 2023; 28:6375. [PMID: 37687205 PMCID: PMC10489045 DOI: 10.3390/molecules28176375] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 08/28/2023] [Accepted: 08/30/2023] [Indexed: 09/10/2023] Open
Abstract
G-protein-coupled receptors (GPCRs) are ubiquitous sensors and regulators of cellular functions. Each GPCR exists in complex aggregates with multiple resting and active conformations. Designed to detect weak stimuli, GPCRs can also activate spontaneously, resulting in basal ligand-free signaling. Agonists trigger a cascade of events leading to an activated agonist-receptor G-protein complex with high agonist affinity. However, the ensuing signaling process can further remodel the receptor complex to reduce agonist affinity, causing rapid ligand dissociation. The acutely activated ligand-free receptor can continue signaling, as proposed for rhodopsin and μ opioid receptors, resulting in robust receptor activation at low agonist occupancy with enhanced agonist potency. Continued receptor stimulation can further modify the receptor complex, regulating sustained ligand-free signaling-proposed to play a role in opioid dependence. Basal, acutely agonist-triggered, and sustained elevated ligand-free signaling could each have distinct functions, reflecting multi-state conformations of GPCRs. This review addresses basal and stimulus-activated ligand-free signaling, its regulation, genetic factors, and pharmacological implications, focusing on opioid and serotonin receptors, and the growth hormone secretagogue receptor (GHSR). The hypothesis is proposed that ligand-free signaling of 5-HT2A receptors mediate therapeutic effects of psychedelic drugs. Research avenues are suggested to close the gaps in our knowledge of ligand-free GPCR signaling.
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Affiliation(s)
- Wolfgang Sadee
- Cancer Biology and Genetics, College of Medicine, The Ohio State University, Columbus, OH 43210, USA;
- Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94158, USA
- Aether Therapeutics Inc., Austin, TX 78756, USA
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Hemanth P, Nistala P, Nguyen VT, Eltit JM, Glennon RA, Dukat M. Binding and functional structure-activity similarities of 4-substituted 2,5-dimethoxyphenyl isopropylamine analogues at 5-HT 2A and 5-HT 2B serotonin receptors. Front Pharmacol 2023; 14:1101290. [PMID: 36762110 PMCID: PMC9902381 DOI: 10.3389/fphar.2023.1101290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 01/10/2023] [Indexed: 01/26/2023] Open
Abstract
Certain 4-substituted analogs of 1-(2,5-dimethoxyphenyl)isopropylamine (2,5-DMA) are psychoactive classical hallucinogens or serotonergic psychedelic agents that function as human 5-HT2A (h5-HT2A) serotonin receptor agonists. Activation of a related receptor population, h5-HT2B receptors, has been demonstrated to result in adverse effects including cardiac valvulopathy. We previously published on the binding of several such agents at the two receptor subtypes. We hypothesized that, due to their structural similarity, the 5-HT2A and 5-HT2B receptor affinities of these agents might be related, and that QSAR studies might aid future studies. For a series of 13 compounds, it is demonstrated here that i) their published rat brain 5-HT2 receptor affinities are significantly correlated with their h5-HT2A (r = 0.942) and h5-HT2B (r = 0.916) affinities, ii) as with r5-HT2 receptor affinity, h5-HT2A affinity is correlated with the lipophilicity of the 4-position substituent (r = 0.798), iii) that eight of the ten compounds examined in functional (Ca+2 mobilization in stable cell lines generated expressing the human 5-HT2B receptor using the Flp-In T-REx system) assays acted as h5-HT2B agonists (4-substituent = H, F, Br, I, OCH2CH3, NO2, nC3H7, tC4H9) and two (n-hexyl and benzyl) as antagonists, iv) h5-HT2B affinity but not action was correlated with the lipophilicity of the 4-position substituent (r = 0.750; n = 10). The findings suggest that h5-HT2B receptor affinity, and its relationship to substituent lipophilicity, might be approximated by rat and h5-HT2A affinity but cannot be used as a predictor of h5-HT2B agonist action of 2,5-DMA analogs. Furthermore, given that certain 2,5-DMA analogs are on the clandestine market, their potential to produce cardiac side effects following persistent or chronic use via activation of h5-HT2B receptors should be considered.
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Affiliation(s)
- Prithvi Hemanth
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, VA, United States
| | - Pallavi Nistala
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, VA, United States
| | - Vy T. Nguyen
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
| | - Jose M. Eltit
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
| | - Richard A. Glennon
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, VA, United States,*Correspondence: Richard A. Glennon, ; Małgorzata Dukat,
| | - Małgorzata Dukat
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, VA, United States,*Correspondence: Richard A. Glennon, ; Małgorzata Dukat,
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The Bright Side of Psychedelics: Latest Advances and Challenges in Neuropharmacology. Int J Mol Sci 2023; 24:ijms24021329. [PMID: 36674849 PMCID: PMC9865175 DOI: 10.3390/ijms24021329] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 12/31/2022] [Accepted: 01/05/2023] [Indexed: 01/12/2023] Open
Abstract
The need to identify effective therapies for the treatment of psychiatric disorders is a particularly important issue in modern societies. In addition, difficulties in finding new drugs have led pharmacologists to review and re-evaluate some past molecules, including psychedelics. For several years there has been growing interest among psychotherapists in psilocybin or lysergic acid diethylamide for the treatment of obsessive-compulsive disorder, of depression, or of post-traumatic stress disorder, although results are not always clear and definitive. In fact, the mechanisms of action of psychedelics are not yet fully understood and some molecular aspects have yet to be well defined. Thus, this review aims to summarize the ethnobotanical uses of the best-known psychedelic plants and the pharmacological mechanisms of the main active ingredients they contain. Furthermore, an up-to-date overview of structural and computational studies performed to evaluate the affinity and binding modes to biologically relevant receptors of ibogaine, mescaline, N,N-dimethyltryptamine, psilocin, and lysergic acid diethylamide is presented. Finally, the most recent clinical studies evaluating the efficacy of psychedelic molecules in some psychiatric disorders are discussed and compared with drugs already used in therapy.
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Vamvakopoulou IA, Narine KAD, Campbell I, Dyck JRB, Nutt DJ. Mescaline: The forgotten psychedelic. Neuropharmacology 2023; 222:109294. [PMID: 36252614 DOI: 10.1016/j.neuropharm.2022.109294] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 09/16/2022] [Accepted: 10/10/2022] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Mescaline (3,4,5-trimethoxyphenethylamine) is one of the oldest hallucinogens, with evidence of use dating back 5700 years. Mescaline is a naturally occurring alkaloid found in cacti, mainly in the peyote cactus (Lophophora williamsii) and in the cacti of the Echinopsis genus. Since the prohibition of psychoactive substances in the early 70s, research on mescaline and other classical psychedelics has been limited. OBJECTIVES This article aims to review the pharmacology and behavioural effects of mescaline, focusing on preclinical and clinical research. FINDINGS Mescaline is a serotonin 5HT2A/2C receptor agonist, with its main hallucinogenic effects being mediated via its 5HT2A receptor agonist action. It also exerts effects via agonist binding at α1A/2A noradrenaline and D1/2/3 dopamine receptors. Overall, mescaline has anxiolytic-like effects in animals and increases prosocial behaviour, locomotion, and response reactivity. In humans, mescaline can induce euphoria, hallucinations, improvements in well-being and mental health conditions, and psychotomimetic effects in a naturalistic or religious setting. CONCLUSION The pharmacological mechanisms of mescaline are similar to those of other classical psychedelics, like psilocybin and lysergic acid diethylamide (LSD). Mescaline appears to be safe to consume, with most intoxications being mild and easily treatable. Improvement in mental well-being and its ability to overcome alcoholism render mescaline potentially beneficial in clinical settings. This article is part of the Special Issue on 'Psilocybin Research'.
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Affiliation(s)
- Ioanna A Vamvakopoulou
- Neural Therapeutics Inc., Toronto, Ontario, Canada; Centre for Psychiatry, Division of Brain Sciences, Imperial College London, Commonwealth Building, Hammersmith Campus, 160 Du Cane Road, London, W12 0NN, United Kingdom
| | | | - Ian Campbell
- Neural Therapeutics Inc., Toronto, Ontario, Canada
| | - Jason R B Dyck
- Neural Therapeutics Inc., Toronto, Ontario, Canada; Cardiovascular Research Centre, Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - David J Nutt
- Neural Therapeutics Inc., Toronto, Ontario, Canada; Centre for Psychiatry, Division of Brain Sciences, Imperial College London, Commonwealth Building, Hammersmith Campus, 160 Du Cane Road, London, W12 0NN, United Kingdom.
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