Natural sun blocks

Researchers are adding to the body of knowledge about natural products that show potential as sunscreens. Previous work has shown that an anthocyanin found in colorful foods such as berries and red grapes can protect skin cells from UV-A radiation, which can cause skin cancer. Now, Francesco Cimino at the University of Messina, in Italy, and colleagues report that the compound can also protect skin cells from UV-B radiation, which can cause sunburn as well as cancer (J. Agric. Food Chem., published online May 9, dx.doi.org/10.1021/jf060253x). The compound, cyanidin-3-O-glucoside (top), appears to block an oxidative stress response that occurs in skin cells exposed to sun. Meanwhile, Morris Srebnik of Hebrew University of Jerusalem and colleagues have found that the bacterial metabolite porphyra 334 (bottom) can provide broad-spectrum UV-A protection (Photochem. Photobiol. Sci. 2006, 5, 432). That performance contrasts with those of most commercially available sunscreens, whose UV-A coverage is limited to short-wavelength radiation, according to the researchers.