Selenium is the active center of various enzymes in human body. It has a broad spectrum of functions on human body and is able to resist diseases, prevent aging and enhance immune function in human life, so as to achieve the balance of body function. Selenium can effectively improve the immunity level in terms of cellular immune, humoral immune and non-specific immune functions.
1) Effects of selenium on cellular immune function
a) Selenium can promote lymphokine secretion of lymphocyte.
b) Selenium can enhance cytotoxic function of cells.
2) Effects of selenium on humoral immune function
Selenium can enhance the humoral immunity, stimulate the formation of immunoglobulin. Selenium has activated effect on humoral immunity and can improve the function of immunoglobulin M and G antibodies.
3) Effects of selenium on non-specific immune function
Nonspecific immunity is mainly the phagocytosis and killing function of phagocytic cells (macrophages and neutrophils) against pathogens. Phagocytic cells must first move closer to the pathogens, and then phagocytize and kill them. Selenium impacts the three phases —- chemotaxis, phagocytosis and killing at different degrees.
Selenium can help enhance the phagocytosis and sterilization ability of macrophage. In the course of phagocytosis of macrophages, some peroxides (oxygen free radicals) often escape and invade other parts of macrophages, which causes damage to macrophages. However, glutathione peroxidase in the human body can eliminate these escaped peroxides. Selenium is the significant composition of the glutathione peroxidase. In the case of selenium deficiency, the enzyme activity cannot be fully expressed. So only selenium supplement can give full play to the role of glutathione peroxidase in scavenging the escaped peroxides, which essentially protects macrophages, extends the lifespan of leukocytes, and thoroughly improves the body’s immunity.