Planta Med 2003; 69(8): 692-695
DOI: 10.1055/s-2003-42786
Original Paper
Pharmacology
© Georg Thieme Verlag Stuttgart · New York

Inhibitory Effect of Jujuboside A on Glutamate-Mediated Excitatory Signal Pathway in Hippocampus

Mu Zhang1 , Gangmin Ning1 , Caihua Shou1 , Yinjun Lu1 , Dihui Hong1 , Xiaoxiang Zheng1
  • 1Department of Biomedical Engineering, Zhejiang University, Hangzhou Yuquan, P. R. China
This work was supported by Science and Technology Department of Zhejiang Province (contract No 011106239), Zhejiang Provincial Key Laboratory of Chinese Medicine Screening, Exploitation & Medicinal Effectiveness Appraise For Cardio-cerebral Vascular & Nervous System and the Key Laboratory for Biomedical Engineering of Ministry of Education of China
Further Information

Publication History

Received: November 19, 2002

Accepted: April 12, 2003

Publication Date:
06 October 2003 (online)

Abstract

Jujuboside A (JuA) is a main component of jujubogenin extracted from the seed of Ziziphus jujuba Mill var spinosa (Bunge) Hu ex H F Chou (Ziziphus), which is widely used in Chinese traditional medicine for the treatment of insomnia and anxiety. Previously, we reported the inhibitory effects of JuA on hippocampal formation in vivo and in vitro, the present study was carried out to examine the effects of JuA on glutamate (Glu)-mediated excitatory signal pathway in hippocampus. Microdialysis coupled with high-performance liquid chromatography (HPLC) was used to monitor the changes of Glu levels in the hippocampus induced by penicillin sodium, or a mixture of penicillin sodium and JuA. The results showed that penicillin increased the hippocampal Glu concentration (p < 0.01) and a high dose of JuA (0.1 g/L) significantly blocked penicillin-induced Glu release (p < 0.05). Moreover, the effect of JuA on intracellular Ca2+ changes after the stimulation by Glu was studied in cultured hippocampal neurons with confocal laser scanning microscope (CLSM). It was found that Glu (0.5 mM) induced an intracellular [Ca2+]i increase (p < 0.01), and JuA significantly inhibited the Glu-induced Ca2+ increase. The calmodulin (CaM) antagonist trifluoperazine (TFP) showed a similar inhibitory effect as JuA. These observations suggested that JuA has inhibitory effects on Glu-mediated excitatory signal pathway in hippocampus and probably acts through its anti-calmodulin action.

References

Prof Xiaoxiang Zheng

Department of Biomedical Engineering

Zhejiang University (Yuquan campus)

Hangzhou 310027

P. R. China

Fax: +86-571-87951676

Email: zxx@mail.hz.zj.cn