Biochemical studies of a natural antioxidant isolated from rosemary and its application in cosmetic dermatology.

Oxidative damage to DNA, RNA, proteins and cell membranes occurs when the cellular concentration of reactive oxygen species exceeds the capacity of the cell to eliminate them. Aerobic prokaryotic and eukaryotic organisms have developed a set of cell defense systems to mitigate the damaging effects of reactive oxygen species. Epithelial surfaces contain antioxidants that could be expected to provide a defence against environmental stress caused by reactive oxygen and nitrogen species. Skin, which has a highly differentiated and complex structure, is particularly vulnerable to free radical damage because of its contact with oxygen and with other environmental stimuli. Fruit and vegetables contain several classes of compounds that when ingested can potentially contribute to endogenous modulation of antioxidant defences. The purpose of this study was to investigate the effectiveness of a natural extract derived from rosemary to protect free radical-induced skin damage. We provide evidence that an alcoholic extract of rosemary leaves, Rosm1, is endowed with strong antioxidant activity and, as evaluated by both in vitro and in vivo systems, is capable of inhibiting oxidative alterations to skin surface lipids. The present study provides a preclinical perspective on the interface between the biochemical properties of a natural extract isolated from rosemary leaves, a better understanding of the endogenous antioxidant potential of skin and the real validity of natural antioxidant biotechnology in antiaging skin management.