Protection of photosensitized rats against long ultraviolet radiation by topical application of compounds with structures similar to that of dihydroxyacetone.
Dihydroxyacetone (DHA), a browning agent, protects photosensitive rats and humans against long ultraviolet radiation (UVA, 320-400 nm) and visible (blue) light. The photoprotective efficacy of DHA and structurally similar compounds was assessed as prevention of edema in the paws of psoralen-sensitized rats, after exposure to blacklight fluorescent lamps. Methylglyoxal produced a yellow-brown color and provided nearly the same protection as DHA, whereas monohydroxyacetone did not color the skin and afforded little or no protection. Glyceraldehyde provided a moderate amount of protection, which was enhanced by prior exposure of the agent to alkaline pH. A solution of 5-hydroxymethylfurfuraldehyde was yellow and provided minimal protection by staining the skin rather than browning it. We conclude that the ability to produce a brown color in skin is a useful criterion for screening compounds for photoprotective efficacy against UVA radiation.
D000447:Aldehydes / Q000008:administration & dosage / Q000378:metabolism; D000818:Animals; D004098:Dihydroxyacetone / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000378:metabolism; D008297:Male; D010787:Photosensitivity Disorders / Q000378:metabolism / Q000517:prevention & control*; D051381:Rats; D011919:Rats, Inbred Strains; D013473:Sunscreening Agents / Q000008:administration & dosage*; D014306:Trioses / Q000008:administration & dosage / Q000378:metabolism; D014466:Ultraviolet Rays / Q000009:adverse effects*
D000447:Aldehydes; D013473:Sunscreening Agents; D014306:Trioses; D004098:Dihydroxyacetone