Planta Med 2006; 72(15): 1415-1417
DOI: 10.1055/s-2006-951703
© Georg Thieme Verlag KG Stuttgart · New York

The Role of NK cells in Antitumor Activity of Dietary Fucoidan from Undaria pinnatifida Sporophylls (Mekabu)

Hiroko Maruyama1 , Hidekazu Tamauchi2 , Mariko Iizuka3 , Takahisa Nakano3
  • 1Department of Pathology, School of Allied Health Sciences, Kitasato University, Kitasato Kanagawa, Japan
  • 2Department of Immunology and Microbiology, School of Medicine, Kitasato University, Kitasato, Kanagawa, Japan
  • 3Riken Vitamin, Co., Ltd., Chiyoda-ku, Tokyo, Japan
Further Information

Publication History

Received: April 20, 2006

Accepted: August 8, 2006

Publication Date:
20 October 2006 (eFirst)


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.


Hiroko Maruyama

Department of Pathology

School of Allied Health Sciences

Kitasato University

Kitasato 1-15-1


Kanagawa 228-8555


Phone: +81-42-778-8077

Fax: +81-42-778-8077

Email: maruyama@