Modulation of radioligand binding to the GABA(A)-benzodiazepine receptor complex by a new component from Cyperus rotundus

Biol Pharm Bull. 2002 Jan;25(1):128-30. doi: 10.1248/bpb.25.128.

Abstract

Four sesquiterpenes, beta-selinene, isocurcumenol, nootkatone and aristolone and one triterpene, oleanolic acid were isolated from the ethylacetate fraction of the rhizomes of Cyperus rotundus and tested for their ability to modulate gamma-aminobutyric acid (GABA(A))-benzodiazepine receptor function by radioligand binding assays using rat cerebrocortical membranes. Among these compounds, only isocurcumenol, one of the newly identified constituents of this plant, was found to inhibit [3H]Ro15-1788 binding and enhance [3H]flunitrazepam binding in the presence of GABA. These results suggest that isocurcumenol may serve as a benzodiazepine receptor agonist and allosterically modulate GABAergic neurotransmission via enhancement of endogenous receptor ligand binding.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Binding, Competitive / drug effects
  • Cerebral Cortex / drug effects
  • Cerebral Cortex / metabolism
  • Cyperaceae / chemistry*
  • Flumazenil / metabolism
  • Flunitrazepam / metabolism
  • GABA Modulators / isolation & purification
  • GABA Modulators / pharmacology*
  • In Vitro Techniques
  • Male
  • Plant Extracts / chemistry
  • Plant Extracts / pharmacology
  • Plant Roots / chemistry
  • Radioligand Assay
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, GABA-A / drug effects*
  • Sesquiterpenes / chemistry
  • Sesquiterpenes / isolation & purification
  • Sesquiterpenes / pharmacology*
  • gamma-Aminobutyric Acid / metabolism

Substances

  • GABA Modulators
  • Plant Extracts
  • Receptors, GABA-A
  • Sesquiterpenes
  • Flumazenil
  • gamma-Aminobutyric Acid
  • Flunitrazepam
  • isocurcumenol