Fucoidan is highly branched sulfated polysaccharides based mainly on L-fucose units. Fucoidan is distributed in the intercellular matrix in brown algae. They have anticoagulant and antithrombotic effects by inhibiting thrombin and modulate some cytokine secretion by binding receptor on immune cells. In addition, antitumor activity of fucoidan is related to the activation of macrophage-mediated tumor cell killing and interferes cancer cell metastasis by inhibition of physical interaction between the tumor cell and basement membrane. The objective was to establish the extraction condition of fucoidan from sea mustard and to investigate which molecular size of fucoidan has more effect on the activation of murine macrophage P388D1. Fucoidan was extracted from sea mustard, Undaria pinnatifida, with different pH, temperature, and time. The extracted fucoidan was fractionated with hollow fiber type ultramembrane filter (MWCO; 3, 10, and 30 kDa) to obtain fucoidan with different molecular size. P388D1 was incubated for 5 days with different molecular size of fucoidans with different concentration (0.1-1000 µg/mL). Cell proliferation was assayed by Trypan blue staining and cytoxicity was measured by MTT assay. Cytokines were assayed by Enzyme-linked immunosorbent assay and Western blotting. Our results showed that, optimum extraction conditions for the extraction of fucoidans from sea mustard were estimated to be at pH 1.0 and temperature 70oC for 3 hr. In the presence of 1-1000 µg/mL, fucoidan fraction having 3-10 kDa of molecular size significantly increased cell proliferation (p<0.05). However, fucoidan fraction having 30 kDa of molecular size showed inhibition of cell growth. These results suggest that extraction conditions for fucoidan from sea mustard will be applicable for the production of fucoidan from the brown algae. Macrophage proliferation will contribute on the commercialization of fucoidan products.
S. K. SEUL1, H. S. Shim2, S. B. Kim2, W. C. Choi1, M. J. Oh3, H. R. Kim2, and D. S. Byun2. (1) Department of Biology, Pusan National University, College of Natural Science, Busan, 609-735, South Korea, (2) Faculty of Food Science and Biotechnology, Pukyong National University, College of Fisheries Science, Busan, 608-737, South Korea, (3) Department of Fish Pathology, Yosu National University, Yosusi, Chunnam, Yosu, 550-749, South Korea