ABSTRACT
Selenium is an essential trace element for human and animal health, which has been known to modulate the functions of several selenoproteins. Most of these selenoproteins have some kinds of antioxidant functions. Selenium is incorporated as selenocysteine into selenoprotein, which is encoded by a UGA codon in the selenoprotein mRNA (1). Mammalian selenoproteins have been mostly found to act as antioxidant
functions such as those of glutathione peroxidase (GPx) (2), thioredoxin reductase (TR) (3), selenoprotein P (4), and selenoproteinW (5). The roles of these enzymes had been extensively reviewed in relation to their potential roles in physiological phenomena as antioxidant defense, redox regulation of cytokine, differentiation, apoptosis, and tumorigenesis (6).
