Taurine (from taurus = ox, as it was discovered in ox bile) or 2-aminoethanesulfonic acid is an acidic chemical substance found in bile, urine, as well as juices and fluids of muscle, lungs and nerve tissue of many animals, and plays several important roles in the body and is essential to newborns of many species. While it is often referred to as an amino acid, this is an inaccurate categorization since it does not contain any carboxylic acid functional group. Taurine may also come from synthetic materials.

Chemistry

Taurine is a colorless crystalline substance formed by the hydrolysis of taurocholic acid or after the decarboxylation of cysteine to cysteamine and the subsequent oxidation of cysteamine's sulfhydryl group to sulfonic acid.

Physiology and Pharmacology

Taurine has three major roles in human metabolism:

• It plays a role in digestion. It is conjugated with the bile acids chenodeoxycholic acid and cholic acid to form (usually above the 7 pH of bile) the bile salts, sodium taurochenodeoxycholate and sodium taurocholate (see bile).
• It may assist in the formation of reactive oxygen species for the respiratory burst in neutrophil granulocytes
• There is evidence that it is an inhibitory neurotransmitter in the central nervous system as well as a precursor to epinephrine.

It has been linked to a number of other metabolic functions but its role is not clear.

Uses

It has been tested medically in the treatment of congestive heart failure, cystic fibrosis, diabetes, epilepsy and several other conditions with positive results. It is used by some as a neutralizer for monosodium glutamate . However, neither the harmfulness of monosodium glutamate nor the benefit of taurine has been proven.

Sources of dietary taurine include shellfish and organ meats such as liver.

Taurine, it is hoped, could eventually be used to reverse liver damage caused by alcoholism or a heavy night's drinking. Tests show that taurine can reverse, or even prevent, the build up of liver fat.

Taurine is one of the active ingredients commonly found in energy drinks such as Red Bull, and in pills which often feature caffeine and/or other stimulant ingredients. The manufacturers claim that taurine enhances the effects of caffeine, but to date there have been no studies performed to confirm this.

Taurine is essential for cats; cat food is supplemented with taurine, which is why other pet foods are not recommended for cats. In cats, taurine "helps maintain good eye health, regulate the heart beat, maintain cell membrane stability, and prevent brain cell over-activity" .

Taurine supplements may be important to counteract the effects of human aging on the natural taurine production process. As humans age, hepatic taurine production can fall or fail completely, producing low to no energy; cardiac, digestive, and mental problems; and premature death.

In biomedical research, taurine is also used in buffers for gel electrophoresis of nucleic acids.

Some multi-purpose solutions for contact lenses contain taurine. For example, one provider claims that taurine protects corneal cells from osmotic stress and functions as an antioxidant. Taurine does occur naturally in tears and ocular tissues.