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 Printable version |
The sun protection factor (SPF) inadequately defines broad spectrum photoprotection: demonstration using skin reconstructed
in vitro exposed to UVA, UVB or UV-solar simulated radiation |
European Journal of Dermatology. Volume 13, Number 3, 242-9, May 2003, Investigative report
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 Free Article
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Author(s) : Françoise BERNERD, Corinne VIOUX, François LEJEUNE, Daniel ASSELINEAU |
Summary : Wavelength specific biological damage has been previously identified in human skin reconstructed
in vitro. Sunburn cell and pyrimidine dimers were found after UVB exposure, and alterations of dermal fibroblasts after UVA exposure. These damages permitted us to discriminate UVB and UVA single absorbers. The present study shows that these biological effects can be obtained simultaneously by a combined UVB + UVA exposure using ultraviolet solar simulated light (UV-SSR), which represents a relevant UV source. In addition, the protection afforded by two broad spectrum sunscreen complex formulations was assessed after topical application. These two formulations displayed the same sun protection factor but different UVA protection factors determined by the persistent pigment darkening (PPD) method. Dose response experiments of UVA or UV-SSR showed that the preparation with the highest PF-UVA provided a better protection with regard to dermal damage compared to the other formulation. Using an original UVB source to obtain the UVB portion of SSR spectrum, the preparations provided the same protection. This study strikingly illustrates the fact that the photoprotection afforded by two sunscreen formulations having similar SPF values is not equal with regard to dermal damage related to photoaging. |
Keywords : skin equivalent, UV radiation, sunscreens, dermal damages |
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