These studies were designed to examine the effects of ginsenosides on glutamate neurotransmission. In primary cultures of rat cerebellar granule cells, ginsenosides (Rb1, Rc and Rg1, 500 μg/ml) increased glutamate release which was measured by HPLC, but Re did not show an elevation of glutamate release. However, all of these ginsenosides down-regulated N-methyl-D-aspartate (NMDA)-induced glutamate release. Rc strongly increased glutamate release and elevated intracellular calcium concentrations (Ca2+i) which was measured by ratio fluorometry with FURA-2 AM. These, results indicate that ginsenosides have a homeostatic effect on glutamate neurotransmission, and there is a structure-function relationship among the ginsenosides tested.
- Cerebellar granule cells
- N-methyl-D-aspartate (NMDA)