Inhibitory Effects of Constituents of Gastrodia elata Bl. on Glutamate-Induced Apoptosis in MIR-32 Human Neuroblastoma Cells

  • Lee, Yong-Soo (Department of Physiology, College of Medicine, Kwandong University) ;
  • Ha, Jeoung-Hee (Department of Pharmacology, College of Medicine, Yeungnam University) ;
  • Yong, Chul-Soon (College of Pharmacy, Yeungnam University) ;
  • Lee, Dong-Ung (Department of Biochemistry, College of Natural Science, Dongguk University) ;
  • Huh, Keun (College of Pharmacy, Yeungnam University) ;
  • Kang, Young-Shin (Department of Physiology, College of Medicine, Kwandong University) ;
  • Lee, Sun-Hee (Department of Physiology, College of Medicine, Kwandong University) ;
  • Jung, Mi-Wha (College of Pharmacy, Yeungnam University) ;
  • Kim, Jung-Ae (College of Pharmacy, Yeungnam University)
  • Published : 1999.08.01

Abstract

The inhibitory effects of the constituents of Gastrodia elata Bl. (GE) on glutamate-induced apoptosis in human neuronal cells were investigated using IMR32 human neuroblastoma cells. Glutamate (GLU) induced DNA fragmentation, a hallmark of apoptosis, in a dose-dependent manner. GLU also induced a slow and sustained increase in intracellular $Ca^{2+}$ concentration. Treatment with EGTA, an extracellular $Ca^{2+}$ chelator, in a nominal $Ca^{2+}$ -free buffer solution abolished the GLU-induced intracellular $Ca^{2+}$ increase, indicating that GLU stimulated Ca2+ influx pathway in the IMR32 cells. BAPTA, an intracellualr $Ca^{2+}$ chelator, significantly inhibited the GLU-induced apoptosis assessed by the flow cytometry measuring hypodiploid DNA content indicative of apoptosis, implying that intracellular $Ca^{2+}$ rise may mediate the apoptotic action of GLU. Vanillin (VAN) and p-hydroxybenzaldehyde(p-HB), known constituents of GE, significantly inhibited both intracellular $Ca^{2+}$ rise and apoptosis induced by GLU. These results suggest that the apoptosis-inhibitory actions of the constituents of GE may account, at least in part, for the basis of their antiepileptic activities. These results further suggest that intracelluarl $Ca^{2+}$ signaling pathway may be a molecular target of the constituents of GE.

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