Neuroprotective effects of Toki-Shakuyaku-San (TJ-23) on glutamate induced neuronal death in cultured cerebellar granule cells

The neuroprotective properties of Toki Shakuyaku-San (TJ-23) were investigated in L-glutamic acid (Glu)induced neuronal death in 8 day primary cultured cerebellar granule cells. After a 4h incubation in Mg2+-free Locke's solution at 37 degrees C, the neuronal survival was 88.5%. An application of 100 mu M of Glu into M(2+)-free Locke's solution resulted in 40% neuronal survival. Further application of either 0.05 or 0.5 mg/mL of TJ-23 into the above solution resulted in 65% and 71% of neuronal survival, respectively. In order to investigate the involvement of ions in the active mechanism of TJ-23, we examined Glu-induced neuronal death in the presence or absence of NaCl, Ca2+, and Mg2+. It was observed that TJ-23 selectively inhibited the Ca2+-dependent neuronal death. From these observations, it is inferred that TJ-23 has a neuroprotective effect on Glu-induced neuronal death. (C) 1997 by John Wiley & Sons, Ltd.