Peroxidation in Human Skin and Its Prevention

Abstract

Cosmetics and quasi-drugs will play new important roles in the aging and stressful society. We have proposed 3 clinical concepts, i.e., anti-drying, anti-UV radiation and anti-oxidation to prevent the skin aging. Especially, the importance of anti-oxidation is discussed in this paper. The peroxidation of human skin surface lipids has been investigated by a CL-HPLC (chemiluminescence-high performance liquid chromatography) system. Squalene monohydroperoxide was produced at the forehead and the scalp as well as in the dandruff under daily life conditions in most of the cases. Therefore it was considered that squalene was the first target lipid on a human skin surface by an oxidative stress. In order to confirm the effect of hydroperoxides of the skin on cultured cells and the living skin equivalent, an authentic sample was prepared. We have also clarified the reaction rate constants of the skin surface lipids with singlet oxygen and free radicals. And we have also confirmed that the application of cosmetics and the ingestion of aliments containing antioxidants had a preventive effect against the lipid peroxidation on skin surface.