In the eight-week study, researchers divided 18 four-week-old hairless mice into three equal groups. (Such genetically engineered mice are used in dermatology studies because of the similarity of mouse skin to human.) The first group was exposed to ultraviolet radiation, similar to that found in sunlight, three times a week, increasing from a level causing sunburn up to one inducing minor skin damage. The second group received the same ultraviolet radiation treatment, but each day were swabbed all over with a preparation of ellagic acid, an antioxidant that’s found especially in raspberries, strawberries, cranberries and pomegranates. The third group served as the control, receiving no special treatment at all.
After eight weeks, the ultraviolet-only group exhibited wrinkles and thickening of the skin. The ellagic acid group showed a reduction in wrinkle formation and skin thickening compared to the first group.
In addition, Bae found that, in human skin cells, ellagic acid protected against ultraviolet damage by interfering with the production of matrix metalloproteinase (MMP), a group of enzymes that destroys collagen in damaged skin cells. Ellagic acid also was found to stifle the expression of ICAM, a molecule associated with inflammation.