2019 年 25 巻 4 号 p. 607-611
It has been ascertained in our laboratory that fucoidan, a polysaccharide contained in Saccharina japonica, shows anti-allergic activity through galectin 9 secretion in blood. A crude fucoidan fraction was chromatographically fractionated into three fractions using a Toyopearl-DEAE 650 M column in stepwise elusion with 0, 0.5 and 1.0 M NaCl in 0.05 M Tris-HCl buffer (pH 7.4). Each fraction was assessed using the passive cutaneous anaphylaxis (PCA) reaction. The non-absorbed fraction of the three fractions suppressed PCA, whereas the fractions eluted with 0.5 M and 1.0 M NaCl did not. Moreover, it was discovered that heat treatment of fucoidan at 50 °C for 10 min abolished its anti-allergic activity in the PCA reaction. Using DEAE chromatography, it was demonstrated that heat-treatment of the crude fucoidan fraction decreased the non-absorbed fraction, which possessed the anti-allergic activity, and increased the two fractions eluted with 0.5 M and 1.0 M NaCl. This clearly revealed the importance of temperature in maintaining the anti-allergic activity of fucoidan.