[#1990-02] Change of biological activities of (1-3)-β-D-glucan from Grifola frondosa upon molecular weight reduction by heat treatment, Y. Adachi et al.

Change of biological activities of (1-3)-β-D-glucan from Grifola frondosa upon molecular weight reduction by heat treatment

Adachi Y, Ohno N, Ohsawa M, Oikawa S, Yadomae T.

Laboratory of Immunopharmacology of Microbial Products, Tokyo College of Pharmacy

Changes of biological activities manifested by (1-6)-branched (1-3)-β-D-glucans (from maitake ) of various molecular weights obtained by heat treatment of the corresponding intact β-glucan at 150 degrees C (HD-LE) were examined. The activities assessed in this study were as follows: an antitumor activity, activation of alternative complement pathway, glucose consumption by macrophages, macrophage-mediated lysosomal enzyme activity in culture supernatant and cell lysate, interleukin-1 (IL-1) activity, and adjuvant activity. HD-LE could be classified into three groups: 1) HD-LE 0 h (MW 800,000) which activated all of the biological activities tested, 2) HD-LE 0.5 and 3 h (MW 250,000 and 21,000) which lacked or exhibited low levels of activities such as activation of alternative complement pathway and lysosomal enzyme secretion, 3) HD-LE 6 h (MW 6,400) which only activated glucose consumption and synthesis of lysosomal enzyme. These results suggest that an antitumor glucan is not always a multiple enhancer of host defense mechanisms and that a large molecular weight is required to augment multiple immunological activities.