Background: By its 'protective function', human skin is a potential target for the production of free radicals. The role played by topically applied antioxidants as inhibitors of oxidative stress damage was felt to be worth investigation.
Objective: To investigate the free radical scavenging (superoxide, hydroxyl and peroxyl radicals) and skin penetration of troxerutin in association with ascorbyl palmitate and alpha-tocopheryl succinate, esters of two vitamins commonly used in skin care products.
Methods: The compounds' scavenging activities, in a concentration-dependent manner, were as follows: hydroxyl radicals in a Fenton-based assay; superoxide radicals in a hypoxanthine/xanthine oxidase system; and lipid peroxidation inhibition of liver microsomes was induced by 2,2'-azobis-(2-amidinopropane) dihydrochloride (ABAP).
Results: A synergic action was observed between alpha-tocopheryl succinate and troxerutin for hydroxyl radical scavenging, between the three compounds for superoxide scavenging and between troxerutin and ascorbyl palmitate in lipid peroxidation inhibition.
Conclusion: Using a stripping method, it was shown that the three substances, incorporated in a pharmaceutical preparation, permeated through human epidermis. Thus, this association can improve skin care products for preventing free radical-mediated damage.