April 21 (HealthDay News) -- You probably already knew that berries are nutritious. But new research shows that a compound found in berries, nuts and other fruits might help prevent wrinkles and repair skin damage caused by the sun.

Researchers in Korea applied ellagic acid, an antioxidant found in raspberries, strawberries, cranberries and pomegranates, to human skin cells in the lab and to the skin of hairless mice that had been exposed to strong, ultraviolet rays.

In the human cells, ellagic acid reduced the destruction of collagen and inflammatory response, both major causes of wrinkles.

Researchers had a similar result in 4-week-old mice, which are often used in dermatology studies because their skin is similar to that of humans.

For eight weeks, 12 hairless mice were exposed three times a week to increasing ultraviolet radiation. The exposure would have been strong enough to cause sunburn and skin damage in humans, according to the researchers, from Hallym University in South Korea.

Half of the exposed mice were given daily topical applications of ellagic acid, even on the days in which they did not receive UV exposure. Ellagic acid was not applied to the other mice.

The mice that did not receive ellagic acid developed wrinkles and thickening of the skin that indicates sun damage.

The mice that received the ellagic acid showed less wrinkle formation, according to the study, which was expected to be presented Tuesday at the Experimental Biology 2009 meeting in New Orleans.

In human skin cells, ellagic acid protects against ultraviolet damage by blocking production of matrix metalloproteinase enzymes that break down collagen and reduce the expression of ICAM, a molecule involved with inflammation.

SOURCES: Federation of American Societies for Experimental Biology news release, April 21, 2009