title: Photobiological implications of melanin photoprotection after UVB-induced tanning of human skin but not UVA-induced tanning.
abstract: Repetitive suberythemal UVA and/or UVB exposures were used to generate comparable UV-induced tans in human skin over the course of 2 weeks. To evaluate the potential photoprotective values of those UVA- and/or UVB- induced tans and to avoid the confounding issue of residual UV-induced DNA damage, we waited 1 week before challenging those areas with a 1.5 MED of UVA+UVB after which we measure DNA damage. The results show that the type of UV used to induce skin pigmentation affects the redistribution of melanin in the skin and/or de novo melanin synthesis. The UVA-induced tans failed to even provide a minimal SPF of 1.5, which suggests that producing a tan with UVA-rich sunlamps prior to a holiday or vacation is completely counterproductive.
authors.affiliation: Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Sergio G
authors.initials: SG
authors.lastname: Coelho
authors.forename: Lanlan
authors.initials: L
authors.lastname: Yin
authors.forename: Christoph
authors.initials: C
authors.lastname: Smuda
authors.forename: Andre
authors.initials: A
authors.lastname: Mahns
authors.forename: Ludger
authors.initials: L
authors.lastname: Kolbe
authors.forename: Vincent J
authors.initials: VJ
authors.lastname: Hearing
mesh_terms: D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects / Q000528:radiation effects; D006801:Humans; D008297:Male; D008543:Melanins / Q000494:pharmacology*; D020011:Protective Agents / Q000494:pharmacology*; D012867:Skin / Q000187:drug effects* / Q000528:radiation effects*; D012880:Skin Pigmentation / Q000187:drug effects / Q000528:radiation effects; D055108:Sunbathing; D014466:Ultraviolet Rays
chemical_list: D008543:Melanins; D020011:Protective Agents
keywords: DNA damage; photoprotection; pigmentation; skin; ultraviolet