Chemical oxidation and DNA damage catalysed by inorganic sunscreen ingredients

作者：Rosemary Dunford, Angela Trovato Salinaro, Le-Zhen Cai, Nick Serpone, Satoshi Horikoshi, Hisao Hidaka, John Knowland · 发表于：FEBS Letters · 年份：1997 · DOI：10.1016/s0014-5793(97)01356-2 · 被引用次数：540 · 研究领域：Skin Protection and Aging、Photodynamic Therapy Research Studies、Biocrusts and Microbial Ecology

Titanium dioxide (TiO2) has been noted (US Federal Register, 43FR38206, 25 August 1978) to be a safe physical sunscreen because it reflects and scatters UVB and UVA in sunlight. However, TiO2 absorbs about 70% of incident UV, and in aqueous environments this leads to the generation of hydroxyl radicals which can initiate oxidations. Using chemical methods, we show that all sunscreen TiO2 samples tested catalyse the photo-oxidation of a representative organic substrate (phenol). We also show that sunlight-illuminated TiO2 catalyses DNA damage both in vitro and in human cells. These results may be relevant to the overall effects of sunscreens.