title: Radical protection by differently composed creams in the UV/VIS and IR spectral ranges.
abstract: Modern sunscreens are well suited to provide sufficient protection in the UV range because the filter substances absorb or scatter UV radiation. Although up to 50% of radicals are formed in the visible and infrared spectral range during solar radiation protection strategies are not provided in this range. Previous investigations of commercially available products have shown that in addition to physical filters, antioxidants (AO) are necessary to provide protective effects in the infrared range by neutralizing already formed radicals. In this study, the efficacy of filter substances and AO to reduce radical formation in both spectral ranges was investigated after UV/VIS or IR irradiation. Optical properties and radical protection were determined for the investigated creams. It was found that organic UV filters lower radical formation in the UV/VIS range to 35% compared to untreated skin, independent of the presence of AO. Further reduction to 14% was reached by addition of 2% physical filters, whereas physical filters alone were ineffective in the UV/VIS range due to the low concentration. In contrast, this filter type reduced radical formation in the IR range significantly to 65%; similar effects were aroused after application of AO. Sunscreens which contain organic UV filters, physical filters and AO ensure protection in the complete solar spectrum.
authors.affiliation: Department of Dermatology, Venerology and Allergology, Center of Experimental and Applied Cutaneous Physiology, Charité - Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Martina C
authors.initials: MC
authors.lastname: Meinke
authors.forename: Felicia
authors.initials: F
authors.lastname: Syring
authors.forename: Sabine
authors.initials: S
authors.lastname: Schanzer
authors.forename: Stefan F
authors.initials: SF
authors.lastname: Haag
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Graf
authors.forename: Manuela
authors.initials: M
authors.lastname: Loch
authors.forename: Ingo
authors.initials: I
authors.lastname: Gersonde
authors.forename: Norbert
authors.initials: N
authors.lastname: Groth
authors.forename: Frank
authors.initials: F
authors.lastname: Pflücker
authors.forename: Jürgen
authors.initials: J
authors.lastname: Lademann
mesh_terms: D000818:Animals; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals; D012867:Skin / Q000187:drug effects; D063465:Skin Cream / Q000737:chemistry*; D013055:Spectrophotometry, Infrared / Q000379:methods*; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*; D013473:Sunscreening Agents / Q000737:chemistry / Q000494:pharmacology*; D013552:Swine
chemical_list: D005609:Free Radicals; D013473:Sunscreening Agents