A group of researchers from the University of Barcelona and the CSIC (Spanish National Research Council) have shown that some polyphenolic substances extracted from grapes (flavonoids) can reduce the formation of 'reactive oxygen species' (ROSs) in human epidermis cells that have been exposed to long-wave (UVA) and medium-wave (UVB) ultraviolet radiation.
The study was published in the Journal of Agricultural and Food Chemistry, following the results of in vitro lab tests.
Greater sun protection capacity
The researchers found that the higher the degree of the flavonoids' polymerisation and formation of compounds containing gallic acid, the greater their photoprotective capacity.
The study suggests that these "encouraging results should be taken into consideration in clinical pharmacology using plant-based polyphenolic extracts to develop new photoprotection skin products.”
There are already cosmetics products on the market containing grape compounds but the scientists believe this study now offers a greater understanding of them.
It also supports the idea of using these existing products to protect the skin from cell damage and death caused by solar radiation, as well as increasing understanding of the mechanism by which they act.
Could help prevent sunburn and resulting problems
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 ageing of the dermis and epidermis.
Scientists claim the study has proven that some substances in grapes can reduce the amount of cell damage caused in skin exposed to this radiation.
UV rays act on the skin by activating ROSs. These compounds in turn oxidize macromolecules such as lipids and DNA, stimulating certain reactions and enzymes which cause cell death.
Cecilia Matito, Neus Agell, Susana Sanchez-Tena, Josep L. Torres, Marta Cascante. "Protective Effect of Structurally Diverse Grape Procyanidin Fractions against UV-Induced Cell Damage and Death"
Journal of Agricultural and Food Chemistry 59 (9): 4489-4495, May 2011. DOI: 10.1021/jf103692a.