In vivo augmentation of NK cell activity by methanol extract of cultured cambial meristematic cells of mountain wild ginseng (P4393)

Abstract

Abstract Although mountain wild ginseng (MWG, Panax ginseng C.A.Meyer) has been regarded to be more effective than cultivated ginseng, very few data have been accumulated until now because of its limited availability and expensiveness. Some of us established a technique of isolation and culture of innately undifferentiated cambial meristematic cells from MWG as an attractive alternative. Using methanol extract of cultured MWG cambium-derived cells (MEGC), we here investigated in vivo immunomodulatory effect in a mouse model. Mice were intraperitoneally given MEGC (200 mg/Kg) and adaptive immunity was unaffected by MEGC treatment. Without Ag immunization, splenic NK cell activity in MEGC-treated mice was significantly higher when compared to controls. However, number of NK1.1+ cells and surface expression of activation/ inhibitory receptors and activation markers were unaltered by MEGC. Instead, RT-PCR data clearly demonstrated that MEGC treatment increases constitutive expression of Granzyme B and perforin in fresh spleen cells. When spleen cells were cocultured with Yac-1 in the presence of IL-2, Granzyme B and IFNγ levels were also higher in MEGC-treated group. However, these effects were achieved solely at early phase of culture (< day 1) and lower concentration of IL-2. Collectively, MEGC augments in vivo NK cell activity through up-regulated constitutive expression of cytolytic mediators and data suggest that ginseng may act at early phase of NK cell response.