Immunomodulating activity of ginsenoside Rg1 from Panax ginseng.

The immunomodulatory activity of ginsenoside Rg1 from Panax ginseng was studied in mice using sheep red cells as the antigen. It was found that ginsenoside Rg1 at a dose of 10 mg/kg administered for three consecutive days before immunization increased the number of spleen plaque-forming cell, the titers of sera hemagglutinins as well as the number of antigen-reactive T-cells. Ginsenoside Rg1 also increased the number of T-helper cells with respect to the whole T-cell number and the splenocyte natural killer activity. Ginsenoside Rg1 induced an augmentation of the production of IL-1 by macrophages and exerted a direct mitogenic effect on microcultured thymus cells. Ginsenoside Rg1 also partly restored the impaired immune reactivity by cyclophosphamide treatment.