Glutathione

Description

Glutathione is produced in the human liver and plays a key role in intermediary metabolism, immune response and health, though many of its mechanisms and much of its behavior await further medical understanding. It is also known as gamma-Glutamylcysteineglycine and GHS. It is a small protein composed of three amino acids , cysteine, glutamic acid and glyceine. Glutatione is found in two forms, a monomerthat is a single molecule of the protein, and a dimmer that is two of the single molecules joined together. The monomer is sometimes called reduced glutathione, while the dimmer is also called oxidized glutathione. The monomer is the active form of glutathione. Oxidized glutathione is broken down to the single molecule by an enzyme called glutathione reductase.

Glutathione, in purified extracted form, is a white powder that is soluble in water and in alcohol. It is found naturally in many fruits, vegetables, and meats. However, absorption rates of glutathione from food sources in the human gastrointestinal tract are low.

General use

Glutathione was first isolated in yeast in 1929. Its metabolism in the body was described in 1984, and its role in cancer treatment dates from 1984.

Glutathione is a major antioxidant highly active in human lungs and many other organ systems and tissues. It has many reported uses. It has a critical role in protecting cells from oxidative stress and maintaining the immune system. Higher blood levels of glutathione have been associated with better health in elderly people, but the exact association between glutathione and the aging process has not been determined.

Among the uses that have been reported for glutathione are:

• treatment of poisoning, particularly heavy metal poisons
• treatment of idiopathic pulmonary firbosis
• increasing the effectiveness and reducing the toxicity of cis-platinum, a chemo drug used to treat breast cancer
• treating Parkinson's disease
• lowering blood pressure in patients with diabetes
• increasing male sperm counts in humans and animals
• treatment of liver cancer
• treatment of sickle cell anemia

Claims made about glutathione have included that it will increase energy, improve concentration, slow aging, and protect the skin.

The importance of glutathione is generally recognized, although its specific functions and appropriate clinical use remain under study. Similarly, because ingested glutathione has little or no effect on intracellular glutathione levels, there are questions regarding the optimal method for raising the intracellular levels.

In addition to ongoing studies of the role of glutathione in cancer and cancer therapy, there are currently clinical trials of glutathione in Amyotrophic lateral sclerosis (ALS). The U. S. National Cancer Institute has included glutathione in a study to determine whether nutritional factors could inhibit development of some types of cancer.

European researchers, with support from the Cystic Fibrosis Foundation, are examining the potential uses of inhaled glutathione in cystic fibrosis. Some physicians also use inhaled glutathione in treating airway restriction and asthma . Other studies are investigating whether administration of alpha-lipoic acid, a material that can elevate intracellular glutathione, may be beneficial in restoring the immune system in AIDS patients.

Preparations

Although glutathione is marketed as a nutritional supplement, it does not appear that glutathione supplements actually increase the levels of glutathione inside cells. In human studies, oral doses of glutathione had little effect in raising blood levels. Further, glutathione is so widely distributed in common foods that supplements are not normally required. Supplements of vitamin C are more effective at increasing intracellular glutathione than taking oral glutathione supplements. Oral supplements of whey protein and of alpha-lipoic acid appear to help restore intracellular levels of glutathione.

Glutathione is available as capsules of 50, 100, and 250 milligrams. It is also included in many multivitamin and multi-nutrient formulations.

Precautions

At this time, the only established precautions are sensitivity to any of the inactive ingredients in the preparations of glutathione or the products used to stimulate glutathione levels. This is a discussion of glutathione, not C and whey. There is some new literature that suggests supplementing it may be helpful to some cancer patients, but detrimental to others.

Side effects

There are no established side effects to glutathione or to the substances used to elevate glutathione levels.

Training & certification

Glutathione has been classified as an orphan drug for treatment of AIDS. For this purpose, medical licensure is required. Glutathione has been given intravenously for amelioration of the side effects of cisplatin therapy. Specific training is required to order, prepare, start, and monitor intravenous therapy. No specific training is required to use glutathione or the compounds which have been reported to raise glutathione levels for other purposes.

Resources

BOOKS

Pressman, A. H. Glutathione: the Ultimate Antioxidant. New York: St. Martin's Press, 1997.

Rozzorno J. E., J. T. Murray, eds. Textbook of Natural Medicine, 2nd ed. Edinborough, Scotland: Churchill Livingston, 1999.

PERIODICALS

Carlo, M. D. Jr, and R. F. Loeser. "Increased oxidative stress with aging reduces chondrocyte survival: correlation with intracellular glutathione levels." Arthritis Rheum (December 2003): 3419–30.

Hamilton D., and G. Batist. "Glutathione analogues in cancer treatment." Curr Oncol Rep (March 2004): 116–22.

Wessner, B., E. M. Strasser, A. Spittler, and E. Roth. "Effect of single and combined supply of glutamine, glycine, N-acetylcysteine, and R, S-alpha-lipoic acid on glutathione content of myelomonocytic cells." Clin Nutr (December 2003): 515–22.

Witschi A., S. Reddy, B. Stofer, and B. H. Lauterburg. "The systemic availability of oral glutathione." Eur J Clin Pharmacol

Wu, G., Y. Z. Fang, S. Yang, J. R. Lupton, and N. D. Turner. "Glutathione metabolism and its implications for health." J Nutr (March 2004): 489–92.

Zenger, F., S. Russmann, E. Junker, C. Wuthrich, M. H. Bui, and B. H. Lauterburg. "Decreased glutathione in patients with anorexia nervosa. Risk factor for toxic liver injury?" Eur J Clin Nutr. (February 2004): 238–43.

ORGANIZATIONS

ALS Therapy Development Foundation. 215 First Street, Cambridge Mass. 02142.

Cystic Fibrosis Foundation. 6931 Arlington Road, Bethesda MD 20814.

NCCAM Clearinghouse. P.O. Box 7923 Gaithersburg, MD 20898.

Samuel Uretsky, Pharm.D.

glutathione The tripeptide of glutamic acid, cysteine, and glycine, which is universally found in animal tissue. It functions as a coenzyme for some enzymes, e.g. for glyoxalase. Also it appears to act as an antioxidant, protecting the sulphydryl groups of certain enzymes and proteins.

glutathione A peptide comprising the amino acids glutamic acid, cysteine, and glycine. It occurs widely in plants, animals, and microorganisms, serving chiefly as an antioxidant. Reduced glutathione reacts with potentially harmful oxidizing agents and is itself oxidized. This is important in ensuring the proper functioning of proteins, haemoglobin, membrane lipids, etc. Glutathione is also involved in amino acid transport across plasma membranes.

glutathione A tripeptide of glycine, glutamic acid, and cysteine (γ‐glutamyl‐cysteinyl‐glycine) which is involved in oxidation‐reduction reactions, the conjugation of foreign substances for excretion and the transport of some amino acids into cells.