RESUMEN
Cancer survivors are highly motivated to seek information about the use of dietary supplements and complementary nutritional therapies to improve their quality of life. Fucoidan, a sulfated polysaccharide extracted from brown marine alga, exhibits a wide range of bioactivities, including anticancer activity. As natural killer (NK) cells serve an important role in defenses against tumor cells, the present study examined the effects of fucoidan extracted from Cladosiphon Okamuranus on NK cell activity in cancer survivors. A prospective, open-label clinical study was conducted on cancer survivors treated with fucoidan via oral administration; 11 cancer survivors with a performance status of 0 or 1 participated and consumed 3 g of fucoidan for 6 months. No significant changes were observed in the mean activities of NK cells in total subjects following the ingestion of fucoidan. An analysis of each sex revealed that NK cell activity was significantly increased by the ingestion of fucoidan in male, yet not female subjects. Serum fucoidan levels were markedly increased following the ingestion of fucoidan and the peak levels ranged between 30 and 198 ng/ml. Tumor markers remained within the reference range during the trial period in subjects, in whom primary tumors were eradicated by treatment. The basal values of tumor markers were elevated in three cases; tumor markers were increased in two cases and decreased in one by the ingestion of fucoidan. These findings suggest that fucoidan enhances the activation of NK cells in male cancer survivors.
RESUMEN
Okinawa mozuku (Cladosiphon okamuranus Tokida) is an edible seaweed classified as brown algae and is a native species of the Ryukyu Islands in Japan. In recent years, the genomic decoding of Okinawa mozuku has been completed. Previous studies on the anti-inflammatory, antiviral, and antitumor properties of Okinawa mozuku have suggested that it affects the regulation of cellular and humoral immunity. The aim of the present study was to examine the immunoregulatory effect of fucoidan derived from Okinawa mozuku in mice. A product containing fucoidan (purity, 88.3%; molecular weight, 49.8 kDa) was developed from Okinawa mozuku and tested for its immunoregulatory effects in mice. The experimental animals were 8-week-old female BALB/c mice to which fucoidan (0, 102.5, 205.0, 410.0, and 1025.0 mg/kg) was administered orally continuously for six weeks. Immune cell proliferation, cytokine production, macrophage phagocytosis, and serum antibody concentration were measured. We found that immune cell proliferation, interleukin (IL)-2, macrophage phagocytes, and serum antibodies (IgM, -G, -A) increased significantly, but IL-4, -5, and IgE decreased significantly. These results indicated that fucoidan modulated cellular and humoral immunity.