Ellagic acid is the antioxidant in question. It is found abundantly in a variety of fruits including raspberries, strawberries, cranberries and pomegranates. Researchers at Hallym University in the Republic of Korea exposed human skin cells and the sensitive skin of hairless mice to UV-B, which are the skin-damaging ultraviolet radioactive rays emitted by the sun.

The team used 12 hairless mice for the experiment and exposed them to increasing ultraviolet radiation for eight weeks. Half of the mice received 10 microM topical applications of ellagic acid on their skin surface, while the other half received nothing. The mice exposed to UV radiation but not ellagic acid, developed thickened skin and wrinkles, while the mice that received ellagic acid did not develop wrinkles.

The research team used topical application of the antioxidant ellagic acid to test its photoprotective effects. They found that ellagic acid was able to block the production of MMP (matrix metalloproteinase) enzymes in the skin. These enzymes are responsible fo the break down collagen in damaged skin cells.

Ellagic acid was also able to reduce the expression of ICAM, which is a molecule involved in inflammatory process. Wrinkles are mainly caused by collagen destruction and inflammatory response. By preventing these two processes from occurring, ellagic acid protected the skin from sun damage and subsequent appearance of wrinkles.

The details of the study were presented at the Experimental Biology 2009 meeting in New Orleans by Ji-Young Bae, who is a graduate student in the laboratory of Dr. Young-Hee Kang.