Ultraweak photon emission of human skin in vivo: Influence of topically applied antioxidants on human skin

This chapter discusses the method to detect ultraweak photon emission (UPE) of human skin in vivo. The monitoring of UPE directly on the skin has the advantages of being noninvasive and providing continuous and convenient monitoring. The effect of the topical application of a-tocopherol and B-carotene was also determined in this study. The UPE detection method provides a useful technique in vivo to determine peroxidative events and efficacy of topically applied antioxidants on human skin. To record the emissions from the skin of human volunteers in vivo, the instruments have to be adapted to special applications. It is necessary to replace small sample compartments and to keep the distance between photocathode and skin surface as short as possible. Avoidance of light from external sources is also necessary. The entire detector head has to be installed in rooms without phosphorescent walls, surfaces, and lamps, and it should be freely movable. Irrespective of theoretical considerations as to whether some kind of physical or biochemical phenomena may be occurring, skin as an organ designed for protection against noxious materials in the environment may be useful as an indicator of free-radical metabolism.