Ultraviolet radiation is harmful for human skin, and photo-damaging pathologies such as actinic erythema, or redness of the skin, are formerly described as a consequence of UV direct effect on DNA and indirectly by local immune reactions.
The lack of understanding of the degree of participation of oxidative stress in actinic erythema and the role of antioxidants in photo-protection led a group of researchers from the University of Malaga to find out more.
A soothing combination
They decided to evaluate the possible soothing role of a combination of the antioxidants vitamins C and E in human cutaneous erythema when applied topically before and after UV exposure.
The study included 20 volunteers of photo-types II, II–III and III with no solar exposure for two months prior to the study.
The volunteers were submitted to a photo-test consisting on the analysis of the minimal erythemal dose (MED) under different treatments: untreated irradiated skin; irradiated skin previously treated with vehicle; irradiated skin previously treated with a combination of vitamins (2.5 per cent vit E–5 per cent vit C); and skin treated with the antioxidant combination after irradiation.
Antioxidant vs vehicle
According to results, published in The Journal of Dermatological Science, the application of vehicle did not significantly affect the MED compared to untreated irradiated skin.
The application of the antioxidant combination, prior to irradiation, increased the MED in all photo-types compared with untreated irradiated skin with an average increase of 36.9 per cent. Antioxidants applied after exposure promoted an average increase of the MED by 19.8 per cent.
Due to this, the researchers concluded that a combination of topical antioxidants (vitamins C and E) showed photo-protection activity against erythema, mainly owing to their high absorption properties.
“Moreover, their antioxidant activity could be considered as additive, and independent of their optical properties,” said the study.