Effects of Valeriana Officinalis Extracts on [3H]Flunitrazepam Binding, Synaptosomal [3H]GABA Uptake, and Hippocampal [3H]GABA Release
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- Ortiz, J.G., Nieves-Natal, J. & Chavez, P. Neurochem Res (1999) 24: 1373. doi:10.1023/A:1022576405534
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Extracts of Valeriana officinalis have been used in folkloric medicine for its sedative, hypnotic, tranquilizer and anticonvulsant effects, and may interact with γ-aminobutyric acid (GABA) and/or benzodiazepine sites. At low concentrations, valerian extracts enhance [3H]flunitrazepam binding (EC50 4.13 × 10−10 mg/ml). However, this increased [3H]flunitrazepam binding is replaced by an inhibition at higher concentrations (IC50 of 4.82 × 10−1 mg/ml). These results are consistent with the presence of at least two different biological activities interacting with [3H]flunitrazepam binding sites. Valerian extracts also potentiate K+ or veratridine-stimulated release of radioactivity from hippocampal slices preloaded with [3H]GABA. Finally, inhibition of synaptosomal [3H]GABA uptake by valerian extracts also displays a biphasic interaction with guvacine. The results confirm that valerian extracts have effects on GABAA receptors, but can also interact at other presynaptic components of GABAergic neurons.