CORK EXTRACTS AS UV PROTECTIVE AGENTS

UV radiation can induce a series of biological responses on the human skin, such as photoaging or skin cancer. The dermis is mainly constituted by fibroblasts, while keratinocytes are the most common cells in the epidermis. Both types of cells have developed the ability to repair their DNA, although, at high doses of UVA (able to penetrate through the epidermis into the dermis) and/or UVB (only affects the epidermis) radiation the cells cannot completely recover the provoked damage [1]. This damage is mainly driven by the generation of reactive oxygen species (ROS) that alter the redox status of the intracellular milieu. In this context, it has been reported the use of phenolic compounds to neutralize the ROS species generated by the UV radiation thus protecting skin cells from mutations or death [2-4].

Cork extracts are usually rich in phenolic compounds, which are reported to be strong antioxidants capable to neutralize ROS species. In this study we evaluated the potential protection activity of a set of cork extracts when in culture with human dermal fibroblasts (hDFbs) and human keratinocytes (hKCs). The protection effect from the negative impact of the UV radiation was assessed considering cell metabolic activity and proliferation and DNA quantification. The cells cultured with cork extracts (10µg/mL) and exposed to UV irradiation (30 min of 19mW/cm² of UVA and 6,42mW/cm² of UVB), demonstrated a higher metabolic activity and a reduced cell dead in the presence of some extracts in comparison to extract-free condition and subjected to the same UV radiation. These results reveal that the cork extracts have a protective effect over hDFbs and hKCs, and constitute the first step to further explore the tested conditions in complex skin tissue models.