Pharmacological screen for activities of 12-hydroxyibogamine: a primary metabolite of the indole alkaloid ibogaine

Psychopharmacology (Berl). 1996 Sep;127(1):10-8. doi: 10.1007/BF02805969.

Abstract

The purported efficacy of ibogaine for the treatment of drug dependence may be due in part to an active metabolite. Ibogaine undergoes first pass metabolism and is O-demethylated to 12-hydroxyibogamine (12-OH ibogamine). Radioligand binding assays were conducted to identify the potency and selectivity profiles for ibogaine and 12-OH ibogamine. A comparison of 12-OH ibogamine to the primary molecular targets identified previously for ibogaine demonstrates that the metabolite has a binding profile that is similar, but not identical to the parent drug. Both ibogaine and 12-OH ibogamine demonstrated the highest potency values at the cocaine recognition site on the 5-HT transporter. The same rank order (12-OH ibogamine > ibogaine), but lower potencies were observed for the [3H]paroxetine binding sites on the 5-HT transporter. Ibogaine and 12-OH ibogamine were equipotent at vesicular monoamine and dopamine transporters. The metabolite demonstrated higher affinity at the kappa-1 receptor and lower affinity at the NMDA receptor complex compared to the parent drug. Quantitation of the regional brain levels of ibogaine and 12-OH ibogamine demonstrated micromolar concentrations of both the parent drug and metabolite in rat brain. Drug dependence results from distinct, but inter-related neurochemical adaptations, which underlie tolerance, sensitization and withdrawal. Ibogaine's ability to alter drug-seeking behavior may be due to combined actions of the parent drug and metabolite at key pharmacological targets that modulate the activity of drug reward circuits.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Binding Sites
  • Brain / metabolism
  • Brain Stem / chemistry
  • Cerebellum / chemistry
  • Cerebral Cortex / chemistry
  • Corpus Striatum / chemistry
  • Dopamine / metabolism
  • Gas Chromatography-Mass Spectrometry
  • Humans
  • Ibogaine / analogs & derivatives*
  • Ibogaine / analysis
  • Ibogaine / metabolism
  • Ibogaine / pharmacology
  • Radioligand Assay
  • Receptors, N-Methyl-D-Aspartate / metabolism
  • Serotonin / metabolism

Substances

  • Receptors, N-Methyl-D-Aspartate
  • Serotonin
  • Ibogaine
  • noribogaine
  • Dopamine