Long-term oral administration of ginseng extract decreases serum gamma-globulin and IgG1 isotype in mice.

Effects of long-term oral administration of ginseng extract on serum protein profile and immunoglobulin (Ig) isotypes were studied in mice. Ginseng extract was orally administered to healthy female mice for 52 days at doses of 30 and 150 mg/kg per day and serum protein electrophoretograms and Ig isotypes levels were evaluated. Serum level of gamma-globulin was decreased dose dependently to 82% (P < 0.05) and 56% (P < 0.01) of control values at the doses of 30 and 150 mg/kg per day, respectively. Levels of total protein, albumin, alpha2- and beta-globulin fractions, as well as the ratio of albumin to globulin (A/G) did not change significantly. However, the alpha1-globulin level increased by 24% (P < 0.05) at the doses of 30 and 150 mg/kg per day. Among the Ig isotypes, including IgG1, IgG2a, IgG2b, IgG3, IgM and IgA, serum IgG1 was dose dependently decreased to 68% (P < 0.05) of control values at the dose of 150 mg/kg per day without significant changes in other Ig isotypes. As IgG1 isotype is rarely cytotoxic and can act as a blocking antibody, it is suggested that the selective decrease in serum IgG1 induced by ginseng extract without changes in the cytotoxic antibodies such as IgG2a may be helpful for the prevention and inhibition of cancer.