PHOTOPROTECTION OF SKIN BY TOPICAL SELENIUM

Ultraviolet (UV) radiation causes oxidative damage to skin which can cause skin cancer, alter the behavior of skin cancer (typically making the cancer more aggressive), and/or cause photoaging. Topical selenium compounds may prevent this damage. In an attempt to moderate UV-induced photodamage, we will formulate topical selenium products and test them in pig skin. Formulations - including selenium sulfite, L-selenomethionine, selenotrisulfide, derivatives of lipoic acid and lipoamide - will be tested for percutaneous absorption in pig skin. Those formulations having the best characteristics will be chosen for further study. We will irradiate normal pig skin with UV radiation. We will assess histological changes and quantitate damage by measuring apoptosis, nucleic acid oxidation, and matrix metalloproteinase induction. We will determine the relative protection of topical selenium formulations to inhibit photodamage.