Effects of ginsenosides on the glutamate release and intracellular calcium levels in cultured rat cerebellar neuronal cells

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.