[Lipoic acid: characteristics and therapeutic application].

Lipoic acid (LA) and its reduced form dihydrolipoic acid (DHLA, are present in all prokaryotic and eukaryotic cells. Lipoic acid was once considered a vitamin, but now it is commonly accepted that it can be synthesized de novo in human cells. LA has long been known as a coenzyme of multienzymatic complexes catalyzing the decarboxylation of alpha-ketoacids, but the present investigations are focused on its antioxidative properties. Both LA and DHLA have proved to be potent free radicals scavengers and metal chelators. They are also responsible for the regeneration of active forms of other cellular antioxidants, including vitamins C and E. Moreover, lipoic acid is involved in the regulation of carbohydrate and lipid metabolism. LA is easily absorbed from the gastrointestinal tract, is able to cross the blood-brain barrier, and does not exhibit any serious side effects. All these features make lipoic acid a very promising drug. Nowadays, this compound is used in the treatment of diabetic neuropathy, fungi, and metal poisoning, as well as in liver disorders. The application of lipoic acid in treating other diseases, including hypertension and autoimmunological disorders, needs careful evaluation.