OPEN Foundation

Day: 5 July 2020

In vitro structure-activity relationship determination of 30 psychedelic new psychoactive substances by means of β-arrestin 2 recruitment to the serotonin 2A receptor

Abstract

Serotonergic psychedelics, substances exerting their effects primarily through the serotonin 2A receptor (5-HT2AR), continue to comprise a substantial portion of reported new psychoactive substances (NPS). The exact mechanisms of action of psychedelics still remain to be elucidated further, and certain pathways remain largely unexplored on a molecular level for this group of compounds. A systematic comparison of substances belonging to different subclasses, monitoring the receptor-proximal β-arrestin 2 recruitment, is lacking. Based on a previously reported in vitro bioassay employing functional complementation of a split nanoluciferase to monitor β-arrestin 2 recruitment to the 5-HT2AR, we here report on the setup of a stable HEK 293 T cell-based bioassay. Following verification of the performance of this new stable cell system as compared to a system based on transient transfection, the stable expression system was deemed suitable for the pharmacological characterization of psychedelic NPS. Subsequently, it was applied for the in vitro assessment of the structure-activity relationship of a set of 30 substances, representing different subclasses of phenylalkylamine psychedelics, among which 12 phenethylamine derivatives (2C-X), 7 phenylisopropylamines (DOx) and 11 N-benzylderivatives (25X-NB). The resulting potency and efficacy values provide insights into the structure-activity relationship of the tested compounds, overall confirm findings observed with other reported in vitro assays, and even show a significant correlation with estimated common doses. This approach, in which a large series of psychedelic NPS belonging to different subclasses is comparatively tested, using a same assay setup, monitoring a receptor-proximal event, not only gives pharmacological insights, but may also allow prioritization of legal actions related to the most potent -and potentially dangerous- compounds.

Pottie, E., Cannaert, A., & Stove, C. P. (2020). In vitro structure–activity relationship determination of 30 psychedelic new psychoactive substances by means of β-arrestin 2 recruitment to the serotonin 2A receptor. Archives of Toxicology94(10), 3449-3460; 10.1007/s00204-020-02836-w
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Historic psychedelic drug trials and the treatment of anxiety disorders

Abstract

Introduction: In this paper, we systematically review literature from 1940 to 2000 relating to the combined use of psychological therapies and psychedelic drugs in the treatment of ICD-10 anxiety disorders.

Methods: The databases Ovid MEDLINE(R), PsycINFO, and Multidisciplinary Association for Psychedelic Studies (MAPS) were searched for case reports and trials involving humans in the treatment of ICD-10 anxiety and related disorders. Twenty-four studies are described; four describe anxiety symptoms in diverse patient groups, 14 studies describe historic diagnoses that usefully correspond with ICD-10 anxiety disorders, six studies pooled results or failed to detail results specific to contemporary ICD-10 anxiety disorders. Two of the 24 studies reported are individual case reports while two of them were inadequate in terms of the reporting of outcome measures. Thus 20 studies were ultimately included in the summary analysis.

Results: Three of the 20 studies reviewed described improvements in anxiety by standardized measures (p < .05) and two studies found that this effect was dose related. Of the 20 studies included in the final analysis, 94 of 145 (65%) cases of “psychoneurotic anxiety reaction” as defined by Diagnostic and Statistical Manual of Mental Disorders-I showed improvement that ranged from moderate improvement to full recovery. Despite methodological inadequacies, the results from previous studies are encouraging and should be used to guide and inform further investigation.

Conclusion: The majority of studies indicate that a combination of psychedelic drug administration and psychological therapy was most beneficial. We found no study suggesting that the pharmacological action of psychedelic drugs in isolation is sufficient.

Weston, N. M., Gibbs, D., Bird, C. I., Daniel, A., Jelen, L. A., Knight, G., … & Rucker, J. J. (2020). Historic psychedelic drug trials and the treatment of anxiety disorders. Depression and Anxiety37(12), 1261-1279; 10.1002/da.23065
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30 April - Q&A with Rick Strassman

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