title: Effects of a sunscreen formulation on albino hairless mice: a morphological approach.
abstract: The purpose of the study was to evaluate the effects of a sunscreen formulation on the skin of albino hairless mice subjected to simulated solar light (SSL) in terms of morphological changes. Young adult albino hairless mice HRS/J (n = 36) were used as an experimental model for determining skin photoaging changes. Mice were irradiated with SSL, and the sunscreen (estimated SPF 30, PF-UVA) was obtained from the Pharmacy College/UFRJ, Brazil. The animals were divided into four groups: non-treated (G1), radiation only (G2), sunscreen-treated (G3) and vehicle + radiation (G4). Animals from groups G2, G3 and G4 were irradiated weekly (5 weeks), with no immobilization. One week after the final exposure, the dorsal skin was observed using a dermatoscopic camera. Biopsies were analyzed in order to quantify neovascularization and to evaluate histological aspects of the skin. Neovascularization was also evaluated with immunohistochemical reactions for the Von Willebrand factor. Animals from G2 displayed classical morphological changes denoting skin photoaging: thickening of the epidermis, increased dermal cellularity, follicular keratosis, sebaceous gland hyperplasia, and angiogenesis. Animals from groups G3 and G1 displayed similar morphological profiles, without these changes. Animals from group G4 showed more morphological changes than group G2, emphasizing the relative importance of the putative photosensitizing components present in the vehicle formulation. The extent of the morphological skin changes suggested that the sunscreen formulation was effective against SSL, and showed the importance of assessing the phototoxicity of vehicle formulations.
authors.affiliation: Programa de Pós Graduação em Ciências Farmacêuticas, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Bryan Hudson
authors.initials: BH
authors.lastname: Hossy
authors.forename: Alvaro Augusto
authors.initials: AA
authors.lastname: da Costa Leitão
authors.forename: Flávio Barbosa
authors.initials: FB
authors.lastname: Luz
authors.forename: Elisabete Pereira
authors.initials: EP
authors.lastname: dos Santos
authors.forename: Silvana
authors.initials: S
authors.lastname: Allodi
authors.forename: Marcelo
authors.initials: M
authors.lastname: de Pádula
authors.forename: Nádia Campos
authors.initials: NC
authors.lastname: de Oliveira Miguel
mesh_terms: D000417:Albinism / Q000235:genetics*; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D001706:Biopsy; D002626:Chemistry, Pharmaceutical; D019610:Cytoprotection; D046169:Dermoscopy; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008812:Mice, Hairless; D009389:Neovascularization, Pathologic; D012867:Skin / Q000098:blood supply / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects*; D015595:Skin Aging / Q000187:drug effects* / Q000473:pathology / Q000528:radiation effects*; D013472:Sunlight / Q000009:adverse effects*; D013473:Sunscreening Agents / Q000737:chemistry / Q000494:pharmacology*; D013997:Time Factors; D014841:von Willebrand Factor / Q000378:metabolism
chemical_list: D015415:Biomarkers; D013473:Sunscreening Agents; D014841:von Willebrand Factor