Soamsan, a traditional Korean medicine, enhances antigen-specific immune responses in low-responder mice via the combined activity of glycoproteins and endotoxins

Soamsan is a traditional anti-cancer treatment in oriental medicine. It is thought that this material modulates immune responses. To determine whether Soamsan treatment has any effect on the induction of antigen-specific immune responses, C57BL/6 mice, which are low-responders to hen egg-white lysozyme (HEL), were injected with HEL, and their specific immune responses were measured while they were fed Soamsan. Oral administration of Soamsan enhanced the anti-HEL antibody response as well as the T-cell proliferative response to the antigen. Analyses of the HEL-specific antibody isotypes showed that Soamsan treatment resulted in increased levels of HEL-specific antibodies, irrespective of isotype. In particular, however, HEL-specific antibodies of the IgG2b, IgG3, and IgM isotypes, which are associated with direct stimulation of B cells, were significantly increased by the Soamsan treatment. Stimulation of C57BL/6 splenocytes in vitro showed that the presence of Soamsan significantly augmented the proliferative activity induced by both B and T cell mitogens. This augmentation was associated with glycoprotein(s) with a molecular weight mass of about 100 kDa, as well as with endotoxin-like compounds. These results suggest that Soamsan modulates and enhances antigen-specific immune responses.