Before I explain about fucoidan and immunomodulation, I would like to discuss about immune system first, basically consists of two mechanisms.

One is innate immunity that is first defense system in which constantly monitors the body and immediately prepares to attack against intruders.

The second is acquired immunity, which is a system that is only available in advanced living organism; it has a strong destructive power and fight against strong enemies such as cancer. This system also has antibodies against specific diseases.

Once taking fucoidan, fucoidan will boost immunity, and first of all, innate immunity, Macrophage, patrol whole body, and when find some foreign particles such as cancer cells, it convey to helper T cells that is like the command tower, and then they request to activate Killer T cells that have the ability kill cancer, and attack them.

Also, fucoidan activate Natural Killer (NK) cells that are always patrolling in a whole body and attack cancer cells and virus-infected cells as soon as they detect them. Fucoidan also activate NK cells that play important role in natural immunity, which is a defense mechanism of the body naturally. NK cells exist 10 to 30 % of lymphocytes present in blood, and have cytotoxic factors such as perforin (protein that opens pores in the cell membrane of target cells) and granzyme (a group of serine proteases that induce cell death in target cells) which they help inducing apoptosis.

In addition, NK cells have two types of antennas: activation receptors and inhibitory receptors. When NK cells encounter virus-infected cells or cancer cells, they receive signals from activated receptors and attack them. On the other hand, when NK cells encounter normal cells, the signal from inhibitory receptor predominates and does not attack normal cells. Thus the reason immune system is important to defense from virus and cancer cells, and fucoidan plays an important role in immune enhancement