RT Journal Article
SR Electronic
T1 Novel psilocin prodrugs with altered pharmacological properties as candidate therapies for treatment-resistant anxiety disorders
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2023.05.16.540994
DO 10.1101/2023.05.16.540994
A1 Sheetal A. Raithatha
A1 Jillian M. Hagel
A1 Kaveh Matinkhoo
A1 Lisa Yu
A1 David Press
A1 Sarah G. Cook
A1 Govinda Sharma
A1 Dhananjaya D.
A1 Glynnis Jensen
A1 Jessica B. Lee
A1 Charlie Cai
A1 Jonathan Gallant
A1 Jaideep S. Bains
A1 Joseph E. Tucker
A1 Peter J. Facchini
YR 2023
UL http://biorxiv.org/content/early/2023/05/18/2023.05.16.540994.abstract
AB The psychedelic compound psilocybin has shown therapeutic benefit in the treatment of numerous psychiatric diseases. A recent randomized clinical trial conducted at Johns Hopkins Bayview Medical Center demonstrated the efficacy of psilocybin-assisted therapy in the treatment of Major Depressive Disorder (MDD). Similarly, a phase IIb study evaluating psilocybin-assisted therapy for treatment-resistant depression (TRD) presented statistically meaningful and long-term reduction in depressive symptoms. Also, many studies have reported the successful treatment of severe anxiety after a single oral dose of psilocybin, especially in patients struggling with cancer-related distress (CRD). Despite these compelling clinical results, concerns regarding the duration of the psychedelic experience produced by psilocybin pose a significant barrier to its widespread therapeutic application. Psilocybin, derived from magic mushrooms is the naturally occurring prodrug of the neuroactive compound psilocin. When orally administered, exposure to the acidic gastrointestinal (GI) environment together with enzymatic processing by intestinal and hepatic alkaline phosphatase lead to the dephosphorylation of psilocybin producing elevated levels of systemic psilocin. These plasma levels are detectable up to 24 h and produce a psychoactive episode lasting as long as 6 h post-ingestion. In order to positively modify the kinetics of the acute psychedelic response, we have engineered a library of novel prodrug derivatives (NPDs) of psilocin, introducing a diversity of alternative metabolically cleavable moieties modified at the 4-carbon position of the core indole ring. This library consists of twenty-eight unique compounds represented by nine distinct prodrug classes. Each molecule was screened in vitro for metabolic stability using isolated human serum, and human cellular fractions derived from liver and intestinal tissues. This screen revealed fifteen prodrugs that produced measurable levels of psilocin in vitro, with ester and thiocarbonate-based prodrug derivatives significantly represented. These fifteen NPDs were further evaluated for pharmacokinetic (PK) profiles in mice, assessing plasma levels of both residual prodrug and resultant psilocin. PK results confirmed the efficiency of ester and thiocarbonate-based prodrug metabolism upon oral and intravenous administration, achieving levels reduced, albeit comparable to levels of psilocybin-derived psilocin. Of note, almost all NPDs tested maintained reduced overall exposure of psilocin relative to psilocybin, with no measurable levels detected at 24 h post-dose. Finally, all NPDs were screened for CNS bioavailability in healthy mice using the Head Twitch Response (HTR), a behavioural biomarker of 5-HT2A receptor stimulation and an established proxy for psychoactive potential. Interestingly, five NPDs produced peak HTR that approached or exceeded levels induced by an equivalent dose of psilocybin. Among these bioactive prodrugs, an ester-based and thiocarbonate-based molecule produced long-term anxiolytic benefit in chronically stressed mice evaluated in the marble burying psychiatric model. Overall, this screening campaign identified novel candidate prodrugs of psilocin with altered metabolic profiles and reduced pharmacological exposure, potentially attenuating the duration of the psychedelic response. These molecules still maintained the long-term psychiatric and physiological benefits characteristic of psilocybin therapy. Additionally, these modified parameters also offer the opportunity for altered routes of administration bypassing conventional oral dosing.Competing Interest StatementAll authors receive compensation from, and Sheetal A. Raithatha, Jillian M. Hagel, Kaveh Matinkhoo, Lisa Yu, David Press, Govinda Sharma, D Dhananjaya, Glynnis Jensen, Jessica B. Lee, Charlie Cat, Jonathan Gallant, Joseph E. Tucker, and Peter J. Facchini hold equity in, Enveric Biosciences, Inc. A United States patent application related to this work has been allowed (17/893,122).