title: Selective Interactions of Valeriana officinalis Extracts and Valerenic Acid with [H]Glutamate Binding to Rat Synaptic Membranes.
abstract: Although GABA neurotransmission has been suggested as a mechanism for Valeriana officinalis effects, CNS depression can also be evoked by inhibition of ionotropic (iGluR) and metabotropic glutamate receptors (mGluR). In this study, we examined if aqueous valerian extract interacted with glutamatergic receptors. Freshly prepared aqueous valerian extract was incubated with rat cortical synaptic membranes in presence of 20 nM [(3)H]Glutamate. Aqueous valerian extract increased [(3)H]Glutamate binding from 1 × 10(-7) to 1 × 10(-3) mg/mL. In the presence of (2S,1'S,2'S)-2-(Carboxycyclopropyl)glycine (LCCG-I) and (2S,2'R,3'R)-2-(2',3'-Dicarboxycyclopropyl)glycine (DCG-IV), Group II mGluR agents, valerian extract markedly decreased [(3)H]Glutamate binding, while (2S)-2-amino-3-(3,5-dioxo-1,2,4-oxadiazolidin-2-yl) propanoic acid) (quisqualic acid, QA), Group I mGluR agonist, increased [(3)H]Glutamate binding. At 0.05 mg/mL aqueous valerian extract specifically interacted with kainic acid NMDA and AMPA receptors. Valerenic acid, a marker compound for Valeriana officinalis, increased the [(3)H]Glutamate binding after 1.6 × 10(-2) mg/mL, and at 0.008 mg/mL it interacted only with QA (Group I mGluR). The selective interactions of valerian extract and valerenic acid with Group I and Group II mGluR may represent an alternative explanation for the anxiolytic properties of this plant.
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.
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Del Valle-Mojica
authors.forename: Yoshira M
authors.initials: YM
authors.lastname: Ayala-Marín
authors.forename: Carmen M
authors.initials: CM
authors.lastname: Ortiz-Sanchez
authors.forename: Bianca A
authors.initials: BA
authors.lastname: Torres-Hernández
authors.forename: Safa
authors.initials: S
authors.lastname: Abdalla-Mukhaimer
authors.forename: José G
authors.initials: JG
authors.lastname: Ortiz