Azelaic acid

A naturally occurring, saturated dicarboxylic acid originally isolated from Pityrosporum ovale, azelaic acid is a rather weak competitive inhibitor of tyrosinase. It is found in grains, such as wheat, rye, and barley In addition, azelaic acid has an antiproliferative and cytotoxic effect on melanocytes. The latter effect occurs because of a rather potent inhibition of thioredoxin reductase, an enzyme involved in mitochondrial oxidoreductase activation and DNA synthesis. Although azelaic acid was initially prescribed for the treatment of acne which works by killing acne bacteria that infect skin pores, and decreases the production of keratin, which is a natural substance that promotes the growth of acne bacteria later it was found that azelaic acid reduces synthesis of melanin. Its efficacy has been compared with hydroquinone 4% in the treatment of facial hyperpigmentation in dark-skinned patients. The combination formula reportedly was as effective as hydroquinone 4% cream, although with a slightly higher rate of local irritation.