Modulation of radioligand binding to the GABA(A)-benzodiazepine receptor complex by a new component from Cyperus rotundus.
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.
Ha
Jeoung-Hee
JH
Department of Pharmacology, College of Medicine, Yeungnam University, Taegu, Korea.
Lee
Kwang-Youn
KY
Choi
Hyoung-Chul
HC
Cho
Jungsook
J
Kang
Byung-Soo
BS
Lim
Jae-Chul
JC
Lee
Dong-Ung
DU
D000818:Animals; D001667:Binding, Competitive / Q000187:drug effects; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D029785:Cyperaceae / Q000737:chemistry*; D005442:Flumazenil / Q000378:metabolism; D005445:Flunitrazepam / Q000378:metabolism; D018757:GABA Modulators / Q000302:isolation & purification / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D018517:Plant Roots / Q000737:chemistry; D011869:Radioligand Assay; D051381:Rats; D017207:Rats, Sprague-Dawley; D011963:Receptors, GABA-A / Q000187:drug effects*; D012717:Sesquiterpenes / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D018757:GABA Modulators; D010936:Plant Extracts; D011963:Receptors, GABA-A; D012717:Sesquiterpenes; D005442:Flumazenil; D005680:gamma-Aminobutyric Acid; D005445:Flunitrazepam; C459499:isocurcumenol