title: Reduced ultraviolet-induced DNA damage and apoptosis in human skin with topical application of a photolyase-containing DNA repair enzyme cream: clues to skin cancer prevention.
abstract: The exposure of human skin to ultraviolet radiation (UVR) results in the formation of DNA photolesions that give rise to photoaging, mutations, cell death and the onset of carcinogenic events. Photolyase (EC 4.1.99.3) is a DNA repair enzyme that reverses damage caused by exposure to UVR. We sought to investigate whether addition of photolyase enhances the protection provided by a traditional sunscreen (SS), by reducing the in vivo formation of cyclobutane-type pyrimidine dimers (CPDs) and UVR-induced apoptosis in human skin. Ten volunteers (Fitzpatrick skin type II) were exposed to solar-simulated (ss) UVR at a three times minimal erythema dose for 4 consecutive days. Thirty minutes prior to each exposure, the test materials [vehicle, SS (sun protection factor 50) alone, and SS plus photolyase from Anacystis nidulans] were applied topically to three different sites. One additional site was left untreated and one received ssUVR only. Biopsy specimens were taken 72 h after the last irradiation. The amount of CPDs and the extent of apoptosis were measured by ELISA. Photolyase plus SS was superior to SS alone in reducing both the formation of CPDs and apoptotic cell death (both P<0.001). In conclusion, the addition of photolyase to a traditional SS contributes significantly to the prevention of UVR-induced DNA damage and apoptosis when applied topically to human skin.
authors.affiliation: San Gallicano Dermatological Institute, IRCCS, Rome, Italy.
authors.forename: Enzo
authors.initials: E
authors.lastname: Berardesca
authors.forename: Marco
authors.initials: M
authors.lastname: Bertona
authors.forename: Karmela
authors.initials: K
authors.lastname: Altabas
authors.forename: Velimir
authors.initials: V
authors.lastname: Altabas
authors.forename: Enzo
authors.initials: E
authors.lastname: Emanuele
mesh_terms: D000287:Administration, Topical; D000328:Adult; D017209:Apoptosis / Q000187:drug effects*; D004249:DNA Damage / Q000187:drug effects*; D004255:Deoxyribodipyrimidine Photo-Lyase / Q000494:pharmacology*; D005260:Female; D006801:Humans; D008297:Male; D012867:Skin / Q000187:drug effects* / Q000528:radiation effects*; D012878:Skin Neoplasms / Q000517:prevention & control*; D013473:Sunscreening Agents / Q000494:pharmacology*; D046940:Synechococcus / Q000201:enzymology; D014466:Ultraviolet Rays
chemical_list: D013473:Sunscreening Agents; D004255:Deoxyribodipyrimidine Photo-Lyase