The
Glutathione Antioxidant System
Mammalian
cells have evolved numerous mechanisms to prevent or treat injurious
events that can result from normal oxidative by-products of cellular
metabolism (oxiradicals).
Glutathione
(GSH) is a tripeptide, found in human cell
tissue, formed from the amino acids cysteine,
glycine, and glutamic acid.
The
"glutathione antioxidant system" is foremost among these
internal protective systems because glutathione participates directly
in the destruction of reactive oxygen compounds.
Glutathione
destroys free radicals, is involved in the detoxification of foreign
compounds such as carcinogens, etc., and supports the normal active
functioning of the immune
system.
Glutathione
exists in the reduced form (GSH), and is in a equilibrium with
its oxidized form (GSSG) - a disulfide. GSH is our body's Master
Antioxidant.
The
principle of action as an antioxidant is based on the fact, that
it reduces other toxic substances before they can demage other
molecules or important parts of the cell. In this case GSH is
oxidized to GSSG. The ratio of GSSG/GSH is an important marker
of oxidative stress.
When
these toxins combine with glutathione, they form a water soluble
compound that can be excreted once and for all by the kidneys.
The highest concentration of glutathione is found in the liver
which is the principal organ involved in the detoxification and
elimination of toxic materials.
See
also:
The
Glutathione Oxidation Reduction (Redox) Cycle
Diagram
of Glutathione disulfide Courtesy of Michael W. King, Professor
IU School of Medicine and IU Center for Regenerative Biology and
Medicine, Terre Haute, IN. 47809
