The role of NK cells in antitumor activity of dietary fucoidan from Undaria pinnatifida sporophylls (Mekabu)

Planta Med. 2006 Dec;72(15):1415-7. doi: 10.1055/s-2006-951703. Epub 2006 Oct 20.


Fucoidan from Mekabu (sporophyll of Undaria pinnatifida), a dietary alga, exerts antitumor activity possibly through enhancing the immune response. The present report describes the effects of dietary Mekabu fucoidan on the tumor growth of mouse A20 leukemia cells and on T cell-mediated immune responses in T cell receptor transgenic (DO-11 - 10 - Tg) mice. The animals were fed with a diet containing 1% Mekabu fucoidan (0.034 +/- 0.003 g/mouse/day) for 10 days and subcutaneously (s. c.) inoculated with A20 leukemia cells. Thereafter, the mice were fed with the diet containing fucoidan for 40 days. Mekabu fucoidan inhibited tumors by 65.4 %. We studied how the killer activities of T cell-mediated and natural killer (NK) cells are augmented in DO-11 - 10 mice fed with Mekabu fucoidan. The cytolytic activities of ovalbumin (OVA), which is specific against OVA-transfected A20 (OVA-A20) B lymphoma cells, and NK cells against YAC-1 were significantly enhanced in the mice fed with fucoidan compared with a basic diet. Thus, these findings suggested that Mekabu fucoidan mediates tumor destruction through Th1 cell and NK cell responses.

MeSH terms

  • Animals
  • Anticarcinogenic Agents / administration & dosage
  • Anticarcinogenic Agents / pharmacology*
  • Anticarcinogenic Agents / therapeutic use
  • Antineoplastic Agents, Phytogenic / administration & dosage
  • Antineoplastic Agents, Phytogenic / pharmacology*
  • Antineoplastic Agents, Phytogenic / therapeutic use
  • Apoptosis
  • Cell Line, Tumor / drug effects
  • Cell Line, Tumor / immunology
  • Dietary Supplements
  • Female
  • Killer Cells, Natural / drug effects*
  • Killer Cells, Natural / immunology
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Ovalbumin / immunology
  • Phytotherapy*
  • Polysaccharides / administration & dosage
  • Polysaccharides / pharmacology*
  • Polysaccharides / therapeutic use
  • Specific Pathogen-Free Organisms
  • Th1 Cells / immunology
  • Undaria*


  • Anticarcinogenic Agents
  • Antineoplastic Agents, Phytogenic
  • Polysaccharides
  • Ovalbumin
  • fucoidan