Effects of bilobalide on amino acid release and electrophysiology of cortical slices.

This study investigated the effects of bilobalide, a constituent of Ginkgo biloba, on potassium and veratridine-induced release of glutamate and aspartate from mouse cortical slices. We also studied its effects on spontaneous and N-methyl-D-aspartate (NMDA)-induced depolarizations elicited in magnesium-free artificial cerebrospinal fluid (aCSF) as well as its effect on NO-711 (a gamma-aminobutyric acid (GABA) uptake inhibitor)-induced depolarizations. Bilobalide, 100 microM significantly reduced both glutamate and aspartate release elicited by potassium or veratridine. Bilobalide (5-100 microM) also significantly reduced the frequency of NO-711 induced depolarizations, however, it had no effect on spontaneous or on NMDA-induced depolarizations at 5-200 microM. These results suggest that the neuroactive properties of bilobalide may be mediated by a reduction in excitatory amino acid neurotransmitter release.