β-1,3-glucans are well known to enhance the immune reactions, resulting in antitumor, antibacterial, antiviral, anticoagulatory and wound healing activities. β-1, 3-glucans have various activities depending on molecular weight, degree of branching, conformation, water-solubility and intermolecular association. However, the β-1,3-glucan linked backbone structure is essential and β-D-glucopyranosyl units are required for immuno-potentiating activities.

In this study, we tested the immunophamacological activities of soluble β-1,3-glucans and confirmed the following activities: (1) IFN-γ production in PBMCs in the presence or the absence of PHA, LPS, or IL-18; (2) induction of various cytokines in the spleen and thymus; (3) adjuvant effect on the antibody production; (4) nitrogen oxide synthesis in macrophages; (5) the cytotoxic and antitumor effects on cell lines and ICR mice.

These results strongly suggested that β-1,3-glucans possessed various immuno-pharmacological activities.