A cranberry extract stimulates procollagen I release and expression after UV radiation in a 3D skin model

The purpose of this study is to evaluate the potential photoprotective effects of a cranberry extract containing proanthocyanins, phenolic acids, and anthocyanins in a full thickness reconstructed human skin model (FTSK).

The effects of a cranberry extract (20 μg/mL) on the release and expression of procollagen I, a precursor to collagen I (main protein structure of human skin) were assessed in FTSK treated with repetitive UV-irradiation (four consecutive days with UVA[+UVB] - 6 J/cm² [+307 mJ/cm²]). The skin model corresponds to the two main human skin components (epidermis and dermis). These effects were also tested on cranberry (poly)phenol metabolites generated during in vitro hepatocyte incubation.

Multiple irradiations of the FTSK induced a strong inhibition of procollagen I release in reconstructed tissue. When the reconstructed tissue was incubated with the cranberry extract, the effects of UV-irradiation were mitigated with a significant stimulation of procollagen I release (p < 0.05). This effect was also observed after digestion of this extract by hepatocytes (p < 0.05), suggesting that its metabolites could also have photoprotective effect, without a clear link with reactive oxygen species induced by photoaging, even if digested extract showed antioxidative species and properties. The cranberry extract and the cranberry (poly)phenol metabolites had no effect on procollagen I expression.

Cranberries may have a photoprotective effect through its ability to stimulate collagen synthesis via procollagen I release.