Identification and Characterization of Cannabidiol as an OX1R Antagonist by Computational and In Vitro Functional Validation

Biomolecules. 2021 Aug 1;11(8):1134. doi: 10.3390/biom11081134.

Abstract

The potential, multifaceted therapeutic profile of cannabidiol (CBD), a major constituent derived from the Cannabis sativa plant, covers a wide range of neurological and psychiatric disorders, ranging from anxiety to pediatric epilepsy and drug addiction. However, the molecular targets responsible for these effects have been only partially identified. In this view, the involvement of the orexin system, the key regulator in arousal and the sleep/wake cycle, and in motivation and reward processes, including drug addiction, prompted us to explore, using computational and experimental approaches, the possibility that CBD could act as a ligand of orexin receptors, orexin 1 receptor of type 1 (OX1R) and type 2 (OX2R). Ligand-binding assays showed that CBD is a selective ligand of OX1R in the low micromolar range (Ki 1.58 ± 0.2 μM) while in vitro functional assays, carried out by intracellular calcium imaging and mobilization assays, showed that CBD acts as an antagonist at this receptor. Finally, the putative binding mode of CBD has been inferred by molecular docking and molecular dynamics simulations and its selectivity toward the OX1R subtype rationalized at the molecular level. This study provides the first evidence that CBD acts as an OX1R antagonist, supporting its potential use in addictive disorders and/or body weight regulation.

Keywords: calcium mobilization assay; cannabidiol; molecular docking; molecular dynamics; orexin receptors.

Publication types

  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Animals
  • Anti-Anxiety Agents / chemistry
  • Anti-Anxiety Agents / metabolism
  • Anti-Anxiety Agents / pharmacology*
  • Anticonvulsants / chemistry
  • Anticonvulsants / metabolism
  • Anticonvulsants / pharmacology*
  • Binding Sites
  • CHO Cells
  • Calcium / metabolism
  • Cannabidiol / chemistry
  • Cannabidiol / metabolism
  • Cannabidiol / pharmacology*
  • Cricetulus
  • Gene Expression
  • Humans
  • Kinetics
  • Molecular Docking Simulation
  • Molecular Imaging
  • Orexin Receptor Antagonists
  • Orexin Receptors / chemistry*
  • Orexin Receptors / genetics
  • Orexin Receptors / metabolism
  • Orexins / chemistry*
  • Orexins / metabolism
  • Protein Binding
  • Protein Conformation, alpha-Helical
  • Protein Conformation, beta-Strand
  • Protein Interaction Domains and Motifs
  • Radioligand Assay
  • Transgenes

Substances

  • Anti-Anxiety Agents
  • Anticonvulsants
  • HCRTR1 protein, human
  • HCRTR2 protein, human
  • Orexin Receptor Antagonists
  • Orexin Receptors
  • Orexins
  • Cannabidiol
  • Calcium