title: Photo-co-carcinogenesis of Topically Applied Retinyl Palmitate in SKH-1 Hairless Mice.
abstract: Cosmetic products that contain retinyl palmitate are popular as antiaging skin treatments; however, recent studies suggest a risk for enhanced skin tumor development with topical retinyl palmitate applications and exposure to solar ultraviolet radiation (UVR). In this study, we investigated the potential of retinyl palmitate to enhance UVR-induced photo-co-carcinogenesis. Groups of 36 male and 36 female SKH-1 hairless mice were exposed to simulated solar light (SSL) and treated with the control cream or creams containing retinyl palmitate, 5 days per week for 40 weeks. Other groups of mice were exposed to SSL and received no cream treatment or received cream treatments and were exposed to ultraviolet-A or ultraviolet-B. Mice were monitored for the development of skin tumors, and the incidences and multiplicities of squamous cell neoplasia were determined by histopathology. In both the absence and presence of SSL, mice administered the control cream developed skin tumors earlier and had higher incidences and multiplicities of skin squamous cell neoplasms than mice that received no cream treatment. Compared to the control cream groups, mice exposed to SSL and administered the retinyl palmitate creams demonstrated earlier onsets of skin tumors and had increased incidences and multiplicities of squamous cell skin neoplasms.
authors.affiliation: Division of Biochemical Toxicology, Food and Drug Administration, National Center for Toxicological Research, Jefferson, Arkansas.
authors.forename: Mary D
authors.initials: MD
authors.lastname: Boudreau
authors.affiliation: Division of Biochemical Toxicology, Food and Drug Administration, National Center for Toxicological Research, Jefferson, Arkansas.
authors.forename: Frederick A
authors.initials: FA
authors.lastname: Beland
authors.affiliation: Division of Bioinformatics and Biostatistics, Food and Drug Administration, National Center for Toxicological Research, Jefferson, Arkansas.
authors.forename: Robert P
authors.initials: RP
authors.lastname: Felton
authors.affiliation: Division of Biochemical Toxicology, Food and Drug Administration, National Center for Toxicological Research, Jefferson, Arkansas.
authors.forename: Peter P
authors.initials: PP
authors.lastname: Fu
authors.affiliation: Office of Scientific Coordination, Food and Drug Administration, National Center for Toxicological Research, Jefferson, Arkansas.
authors.forename: Paul C
authors.initials: PC
authors.lastname: Howard
authors.affiliation: Jefferson Laboratories, Toxicologic Pathology Associates, Inc., Jefferson, Arkansas.
authors.forename: Paul W
authors.initials: PW
authors.lastname: Mellick
authors.affiliation: Division of Bioinformatics and Biostatistics, Food and Drug Administration, National Center for Toxicological Research, Jefferson, Arkansas.
authors.forename: Brett T
authors.initials: BT
authors.lastname: Thorn
authors.affiliation: Jefferson Laboratories, Toxicologic Pathology Associates, Inc., Jefferson, Arkansas.
authors.forename: Greg R
authors.initials: GR
authors.lastname: Olson
mesh_terms: D000287:Administration, Topical; D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000209:etiology*; D003043:Cocarcinogenesis; D004224:Diterpenes; D005260:Female; D008297:Male; D008812:Mice, Hairless; D009381:Neoplasms, Radiation-Induced / Q000139:chemically induced* / Q000209:etiology*; D000084562:Retinyl Esters; D012878:Skin Neoplasms / Q000209:etiology*; D013472:Sunlight / Q000009:adverse effects*; D014466:Ultraviolet Rays / Q000009:adverse effects*; D014801:Vitamin A / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000633:toxicity
chemical_list: D004224:Diterpenes; D000084562:Retinyl Esters; D014801:Vitamin A; C014794:retinol palmitate