Grape Polyphenols Offer UV Protection

BARCELONA, Spain—In vitro results from a recent Spanish study conducted at the University of Barcelona support the use of plant-derived polyphenolic extracts as novel agents for skin photoprotection, warranting further research (J Agric Food Chem. 2011;59(9):4489-95). UV radiation leads to the generation of reactive oxygen species (ROS). These molecules exert a variety of harmful effects by altering key cellular functions and may result in cell death. Several studies have demonstrated human skin can be protected against UV radiation by using plant-derived antioxidants. In this study, researchers evaluated the in vitro capacity of several antioxidant polyphenolic fractions from grape, which differ in their degree of polymerization and percentage of galloylation, to protect HaCaT human keratinocytes against UV-induced oxidative damage. These fractions inhibited both basal and UVB- or UVA-induced intracellular ROS generation in this cell line. Consequently, the same fractions inhibited p38 and JNK1/2 activation induced by UVB or UVA radiation. The highest protective effect was for fractions rich in procyanidin oligomers and gallate esters.