Antitumor Activities of Marine Algae Constituents

Recently immunotherapy has been considered to be an important method to increase immunopotentiating activity of host in the treatment of neoplastic diseases. In the therapy, polysaccharides have attracted attention because of their activity to enhance host defense mechanisms against neolpastic diseases. Some kinds of polysaccharides have been fouud to provide immunopotentiating activity which brought about regression of tumors and helped protect against infectious diseases. In this study, screening tests were conducted for several years for the selection of suitable polysaccharides for clinical trials, and several marine algae containing polysaccharides with immunopotentiating activity were found. Immunostimulant substances, which were collected from brown algae, Sargassum fulvellum C. Agardh, Sargassum thunbergii O. Kuntze and Eisenia bicyclis Setchell, markedly potentiated host antitumor activity which was proved by regression and elimination of the tumor.