The nitroxide Tempol affords protection against ultraviolet radiation in atransgenic murine fibroblast culture model of cutaneous photoaging

The generation of reactive oxygen species is among the various mechanisms b y which ultraviolet radiation damages skin. Tempol, a superoxide dismutase analogue which readily penetrates cell membranes when administered exogenou sly, has been shown to provide protection against some forms of oxygen-depe ndent damage. In this study, we measured the ability of Tempol to protect a gainst ultraviolet A- and ultraviolet B-induced damage, using a previously described transgenic mouse model of cutaneous photoaging. The ability of Te mpol to prevent ultraviolet radiation-induced elastin promoter activation w as determined in vitro. Tempol provided over 50% protection against ultravi olet B and over 70% protection against ultraviolet A as measured in our in vitro system. These results demonstrate the ability of the superoxide dismu tase mimic, Tempol, to protect against ultraviolet induced elastin promoter activation. This compound could be a useful pharmacological agent to preve nt cutaneous photoaging.