Abstract
Cladosiphon okamuranus (Okinawamozuku) is a species of Mozuku known to contain the most fucoidan of any brown algae. Fucoidan is a sulfated hetero polysaccharide with various biological activities. We isolated and purified fucoidan from C. okamuranus. The yield of fucoidan was 1.0% (w/w) based on wet algae from C. okamuranus. The sulfate content and molecular weight of the fucoidan were 9.8% (w/w) and approximately 3,200,000, respectively. We examined the effects of fucoidan on human stomach cell lines. Fucoidan from C. okamuranus showed an inhibitory effect on anticancer agent 5-fluorouracil (5-FU) in Hs 677.st normal stomach cells with minimum inhibition of the original effect of 5-FU in cancer cells. Furthermore, fucoidan from C. okamuranus showed growth inhibition of stomach cancer cells but did not show any effects on normal cells. Thus, fucoidan from Mozuku, especially C. okamuranus, may be useful for cancer therapy.