A cream containing vitamin C, vitamin E and ferulic acid protects the skin from sun damage and reduces cancer-associated mutations in skin cells, new research shows.
The cream's "mechanism of action is different from sunscreens and would be expected to supplement the sun protection provided by sunscreens," Sheldon R. Pinnell, MD, of Duke University Medical Center in Durham, North Carolina, and colleagues write. Pinnell is a consultant to SkinCeuticals-L'Oreal, which makes the cream and also helped to fund the study.
Ultraviolet radiation damages the skin by causing oxidative stress, Pinnell and his team note, and they have been investigating topical applications of antioxidants for neutralizing this damage. In previous research, they demonstrated that vitamins C and E were individually effective for boosting antioxidant protection, and even more effective when used together. In subsequent laboratory studies, they showed that ferulic acid, a plant antioxidant, increased the antioxidant effects of the vitamins even further.
In the current study, the researchers report on the effects of a cream containing 15% vitamin C, 1% vitamin E and 0.5% ferulic acid on human skin.
They applied the cream to nine adult Caucasians and then exposed them to simulated sun irradiation. Compared to a cream with no active ingredients, the ferulic acid cream reduced skin redness after sun exposure and caused fewer skin cells to sunburn. The active cream almost completely blocked the production of thymine dimers, a type of UV-related genetic damage, as well as the induction of the tumor suppressor gene p53. While unprotected skin exposed to UV radiation produced substances called cytokines that promote inflammation and suppress immune system function, protected skin did not.
The findings suggest, the researchers conclude, that the antioxidant cream could be used as a supplement to sunscreen, providing "maximal photoprotection of the skin."
SOURCE: Journal of the American Academy of Dermatology, September 2008.
Reuters, September 18, 2008