ABSTRACT
Skin is a biological interface with the environment, functions as the first line of defense against noxious stimuli, and protects the body’s interior from external insults. This protective mechanism can break down under stresses caused by environmental extremes. The skin is one of the largest body organs and serves as a major portal of entry for many environmental pollutants, some of which are free radical generaters. Lipid peroxidation is one of the molecular consequences of free radical reactions. Skin is a potential target organ of oxidative injury because it is continuously exposed to environmental pollutants, visible and ultraviolet radiation, and high oxygen concentrations and contains a variety of oxidizable lipids critical for maintenance of epidermal barrier function. Peroxidation of skin lipids may cause disturbances of barrier function, induction of inflammatory reactions, impairment of immune surveillance, and predisposition to cancer. Intact skin barrier has important health implications, and barrier function can be measured easily by noninvasive techniques (1). It is established that homeostasis of the physiological skin lipid composition is essential to an intact barrier function, and this field has been thoroughly investigated in past decades. The concentration of lipid peroxidation products in skin is significantly influenced by nutrition (2), cell turnover (3), and environmental factors, solar radiation being the most important determinant. A potential role of environmental oxidants as modulators of skin lipid integrity is emerging, and this chapter is designed to give a brief introduction into this field.
