In vitro photochemical damage to DNA, RNA and their bases by an inorganic sunscreen agent on exposure to UVA and UVB radiation

The fate of DNA, RNA and their pyrimidine and purine bases was examined on exposure to WA and UVB radiation in the presence of a physical sunscreen agent (TiO(2), anatase/rutile particles) to assess the potential damage that such an agent may cause on contact with such substrates. DNA and RNA were partially decomposed and the bases were converted to carbon dioxide (nitrogen atoms to ammonia and nitrate ions) in a Pyrex reactor under conditions simulating UVA and UVB sunlight. The physical and chemical damage inflicted on DNA and RNA was also confirmed by scanning electron microscopy and gel permeation chromatography. (C) 1997 Elsevier Science S.A.