[Protective effects of ginsenoside Rb1 and Rg1 on cultured hippocampal neurons]

It has been well documented that ginsenoside Rb1 and Rg1 are important active principles of ginseng. In the present studies, Rb1 and Rg1 were found to prolong the duration of neuronal life and provided partial protection against the excitotoxic effect of glutamate in primary hippocampal cultures. Since excitotoxic neuronal injury of glutamate is considered to be caused by the increase of intracellular Ca2+ concentrations, the effects of Rb1 and Rg1 on [Ca2+]i elevated by glutamate were measured in cultured hippocampal cells using Fura-2/AM as a calcium indicator. The results showed that Rb1 and Rg1 could selectively inhibit the high level glutamate (500 mumol.L-1) induced increase of [Ca2+]i, suggesting that the neuroprotective activities of Rb1 and Rg1 were mediated by blocking calcium over-influx into neuronal cells.