title: Aqueous and Ethanolic Valeriana officinalis Extracts Change the Binding of Ligands to Glutamate Receptors.
abstract: The effects of two valerian extracts (aqueous and hydroalcoholic) were investigated through [(3)H]Glutamate ([(3)H]Glu) and [(3)H]Fluorowillardine ([(3)H]FW) receptor binding assays using rat synaptic membranes in presence of different receptor ligands. In addition, the extract stability was monitored spectrophotometrically. Both extracts demonstrated interaction with ionotropic glutamate receptors (iGluRs). However, the extracts displayed considerable differences in receptor selectivity. The hydroalcoholic extract selectively interacted with quisqualic acid (QA), group I metabotropic glutamate receptor (mGluR) ligand, while the aqueous extract did not alter the binding of QA. The stability of the extracts was examined during several weeks. Freshly prepared extract inhibited 38-60% of [(3)H]FW binding (AMPA). After 10 days, the aqueous extract inhibited 85% of [(3)H]FW binding while the hydroalcoholic extract markedly potentiated (200%) [(3)H]FW binding to AMPA receptors. Thus, our results showed that factors such as extraction solvent and extract stability determine the selectivity for glutamate receptor (GluR) interactions.
authors.affiliation: Department of Pharmacology and Toxicology, School of Medicine, University of Puerto Rico, Medical Sciences Campus, P.O. Box 365067, San Juan, 00936-5067 Puerto Rico, USA.
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Del Valle-Mojica
authors.forename: José M
authors.initials: JM
authors.lastname: Cordero-Hernández
authors.forename: Giselle
authors.initials: G
authors.lastname: González-Medina
authors.forename: Igmeris
authors.initials: I
authors.lastname: Ramos-Vélez
authors.forename: Nairimer
authors.initials: N
authors.lastname: Berríos-Cartagena
authors.forename: Bianca A
authors.initials: BA
authors.lastname: Torres-Hernández
authors.forename: José G
authors.initials: JG
authors.lastname: Ortíz