In vitro photostability and photoprotection studies of a novel ‘multi-active' UV-absorber

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• 作者：E. Venditti ; T. Spadoni ; L. Tiano ; P. Astolfi ; L. Greci ; G.P. Littarru ; E. Damiani
• 关键词：Ethylhexyl methoxycinnamate ; Nitroxide ; Antioxidant ; UV-absorber ; Sunscreen ; Multi-active ; Liposomes ; Fibroblasts ; UV-A
• 刊名：Free Radical Biology and Medicine
• 出版年：2008
• 出版时间：1 August 2008
• 年：2008
• 卷：45
• 期：3
• 页码：345-354
• 全文大小：921 K

文摘

This paper reports on the synthesis and properties of a new UV-absorber (OC-NO) based on the most popular UV filter worldwide, ethylhexyl methoxycinnamate (OMC) in which the methoxy group has been replaced with a pyrrolidine nitroxide bearing antioxidant activity. This sunscreen active has therefore both UV-absorbing and antioxidant properties which could ideally address both the UV-B and UV-A skin photo-damage. For broad-spectrum coverage, the combinations of OC-NO with two commonly used UV-A absorbers (BMDBM and DHHB) were also studied. The results obtained reveal that OC-NO: (a) is as photostable as OMC after UV-A exposure; (b) acts as free radical scavenger as demonstrated by EPR and chemical studies; (c) reduces UV-A and UV-A+BMDBM induced lipid peroxidation in liposomes and cells, measured as reduced TBARS levels and increased C11-BODIPY red fluorescence, respectively; (d) has comparable antioxidant activity to that of vitamin E and BHT commonly used in skin care formulations; (e) is non-cytotoxic to human skin fibroblasts as assessed with the MTT assay when exposed to increasing doses of UV-A; and (f) OC-NO+DHHB is a promising, photostable broad spectrum UV-filter combination that concomitantly reduces UV-induced free radical damage. These results suggest that nitroxide/antioxidant-based UV-absorbers may pave the way for the utilization of ‘multi-active' ingredients in sunscreens thereby reducing the number of ingredients in these formulations.