Der epidermale Arginin-Stoffwechsel und dessen therapeutische Beeinflussung

Abstract

From a cosmetic and dermatological point of view, arginine, a physiological amino acid, is a promising active substance for topical applications. Arginine is metabolized enzymatically in the arginase reaction to urea and ornithine and in the NO-synthase reaction to NO and citrullin. Urea increases the water binding capacity of the horny skin layer, possesses keratoplastic, bacteriostatic, antimycotic, and proteolytic properties and relieves itching. NO is essentially involved in the regulation of hemo- and lymphovascular perfusion and in initiation and maintenance of inflammatory processes. It possesses immunomodulating and radical trapping properties. Both arginase and NO synthase are expressed in keratinocytes, and also in other cutaneous cells (such as melanocytes, fibroblasts, microvascular endothelial cells) and its activity is functionally influenced by various factors. In relevant concentrations, arginine can be considered safe from a toxicological point of view. As a hydrophilic substance, L-arginine can be easily worked into standard vehicle systems for topical application. L-arginine penetrates into human skin, whereby an adequate concentration time-profile is attained in the living epidermis. The potency of practical use of topically applied L-arginine arises from the biochemical role of arginine in epidermal metabolism. In addition to cosmetic use and therapy of chronic dermatoses, a number of additional applications are possible in functional and structural disruptions of the skin.