Grape Compounds Provide Skin Protection from Ultraviolet Radiation

The study’s findings support the use of grapes or grape derivatives in sun protection products.

Ultraviolet (UV) rays emitted by the sun are the leading environmental cause of skin complaints, causing skin cancer, sunburn, and solar erythema, as well as premature aging of the dermis and epidermis. Now, a Spanish study has confirmed that some substances found in grapes can reduce the amount of cell damage caused in skin exposed to this radiation.

UV rays act on the skin by triggering reactive oxygen species (ROS). These compounds in turn oxidize macromolecules such as lipids and DNA, stimulating specific reactions and enzymes (JNK [c-Jun amino-terminal kinases] and p38MAPK [MAP kinase]) that cause cell death. A group of scientists from the University of Barcelona (Spain) and the CSIC (Spanish National Research Council; Madrid, Spain) have shown that various polyphenolic substances extracted from grapes (flavonoids) can reduce the formation of ROS in human epidermis cells that have been exposed to long-wave (UVA) and medium-wave (UVB) ultraviolet radiation. The study, carried out in vitro in the laboratory, has been published online August 2011 in the Journal of Agricultural and Food Chemistry.

“These polyphenolic fractions inhibit the generation of the ROS, and as a result, the subsequent activation of the JNK and p38 enzymes, meaning they have a protective effect against ultraviolet radiation emitted by the sun,” noted Dr. Marta Cascante, a biochemist at the University of Barcelona and director of the research project.

The researchers discovered that the higher the level of the flavonoids’ polymerization and formation of compounds containing gallic acid, the greater their photoprotective capacity. The study’s findings suggested that these “encouraging results should be taken into consideration in clinical pharmacology using plant-based polyphenolic extracts to develop new photoprotection skin products.”

Cosmetics and drugs containing grape compounds are already available, but the manner in which they act on cells has not been well understood until now. “This study supports the idea of using these products to protect the skin from cell damage and death caused by solar radiation, as well as increasing our understanding of the mechanism by which they act,” concluded Dr. Cascante.

Related Links:
University of Barcelona
CSIC--Spanish National Research Council