Resveratrol

What is resveratrol?

Resveratrol is a natural compound found in many plants and fruits, including the skin of red grapes, eucalyptus, spruce, blueberries, mulberries, peanuts and the root of Japanese knotweed (R). In plants, resveratrol is produced as a form of defense against harmful environmental stimuli, such as fungi or infections (R), and in response to stress conditions such as fluctuations in the climate or exposure to ozone, sunlight and heavy metals (R).

Fresh grape skin contains about 50-100µg of resveratrol per gram wet weight (R). Due to its presence in grape skins, resveratrol is also found in red and white wines, with red wines comtaining between 3-7x more resveratrol than white wines (R).

Does resveratrol get absorbed?

When an ethanol/water solution containing 5% resveratrol was applied to human skin in vivo, most of the resveratrol remained in the layers of the stratum corneum close to the surface, where it exerts its antioxidant activity (R). Resveratrol has also been shown to penetrate the stratum corneum from a formulation containing 1% resveratrol (R). There appear to be specific polyphenol receptor sites in the skin that bind resveratrol. Significant binding has been observed in the epidermis, and some binding in the dermis (R).

In cosmetic formulations, in order to allow resveratrol to be incorporated into creams, it is often encapsulated in microparticles. The use of nanosuspensions and nanocarriers have been shown to increase stability (R), and promote permeation through the skin (14).