We previously reported that ginseng inhibited NMDA receptors in cultured hippocampal neurons. Here, we further examined the detailed mechanism of ginseng-mediated inhibition using its main active ingredient, ginsenoside Rg$_3$. Co-application of ginsenoside Rg$_3$ with increasing concentrations of NMDA did not change the EC$_{50}$ of NMDA to the receptor, suggesting ginsenoside Rg$_3$ inhibits NMDA receptors without competing with the NMDA-binding site. Ginsenoside Rg$_3$-mediated inhibition also occurred in a distinctive manner from the well-characterized NMDA receptor open channel blocker, MK-801, However, ginsenoside Rg$_3$ produced its effect in a glycine concentration-dependent manner and shifted the glycine concentration-response curve to the right without changing the maximal response, suggesting the role of ginsenoside Rg$_3$ as a competitive NMDA receptor antagonist. We also demonstrated that ginsenoside Rg$_3$ significantly protected neurons against NMDA insults. Therefore, these results suggest that ginsenoside Rg$_3$ protects NMDA-induced neuronal death via a competitive interaction with the glycine-binding site of NMDA receptors in cultured hippocampal neurons.

A peroxidase[E.C.1.11.1.7] is very important enzymes,e.g., as preventive antioxidants. The function is connected with growth and specialization of plant. It makes from the peroxidase and other product to save itself When a plant have been under stress of environment. A class III peroxidase cDNA was isolated from the flower bud of Panax ginseng C.A. Meyer and named PgPrx3. The PgPrx3 is an ORF(open reading frame) of 1,065 bp and a amino acid of 355 residue. Used BioEdit software to compare the PgPrx3 amino acid sequence with other plants which have already known a result of Identity was Spinacia oleracea(70%), vigna angularis(71%), Nicotiana tabacum(69%) and Linum usitatissimym(65%). The peroxidase of Vigna angularis has high homology relationship with ginseng. for that reason, the PgPx3 is a member of class III peroxidase.

Introduce of gene connected with disease and transformation system of ginseng, Squalene systhase(PSS) gene cloned from and disease resistant gene were carried out for expression and transformation of plant using Agrobacterium. PSS of 35S-35S-AMV-PSS-Tnos, has been constructed which were mobilized into Agrobacterium tumefaciens strain MP 90 disarmed Ti-plasmid. PSS gene were introduced into the binary vector pRD 400. The transgenic ginseg plants were propagated using repetitive secondary embryogenesis and introduced NPTII and PSS genes of the transgenic ginseng were successfully indentified by the PCR and survival test on the medium.