The antitumor activity of a red alga polysaccharide complexes carrying 5-fluorouracil.

Porphyran is a sulfated galactan isolated from red algae Porphyra haitanensis, and have been reported to have many kinds of biological activities such as antitumor activity. In order to provide a water-soluble macromolecule prodrug of 5-Fu showing slow release of 5-Fu and reducing side-effect, we carried out fixation of 5-Fu to porphyran at 6-position. In this study, the antitumor and immunomodulation activities of low MW porphyran carrying 5-Fu on transplanted S180 tumor mice were studied. Weight of immune organ, proliferation ratio of lymphocyte concentration of TNF-α and NO from the transplanted S180 tumor mice were also determined. Results indicated that the conjugate could enhance antitumor activity of 5-Fu and improve immunocompetence damaged by 5-Fu.