Effect of ultraviolet filters on skin superoxide dismutase activity in hairless mice after a single dose of ultraviolet radiation

Organic sunscreens may decrease their protective capability and also behave as photo-oxidants upon ultraviolet radiation (UVR) exposure. The present study investigated the effect of a cream gel formulation containing the UV filters benzophenone-3, octyl methoxycinnamate, and octyl salicylate on skin superoxide dismutase (SOD) after a single dose of UVR (2.87 J/cm(2)). The retention of these UV filters was first evaluated in vivo using hairless mice to guarantee the presence of the filters in the skin layers at the moment of irradiation. The in vivo effect of the UV filters on skin SOD was then assayed spectrophotometrically via the reduction of cytochrome c. The cream gel formulation promoted the penetration of the three UV filters into the epidermis and the dermis at one hour post-application. A significant decrease in SOD activity was observed in irradiated animals treated with sunscreen formulation. However, no effect on SOD activity in skin was observed by the isolated presence of the sunscreens, the formulation components, or the exposure to UVR. The sunscreens may have formed degradation products under UVR that may have either inhibited the enzyme or generated reactive species in the skin. (C) 2011 Elsevier B.V. All rights reserved.

Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), Brazil

Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP, Brazil)

"Conselho Nacional de Desenvolvimento Cientifico e Tecnologico" (CNPq, Brazil)

Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Brazil

Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES), Brazil

Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES, Brazil)

FAPESP

FAPESP [2009/00924-2]