Department of Medicine. University of Alcalá, Alcalá de Henares, Madrid, Spain
The solar radiation (SR) nature was discovered in 1801. From this date to now, the advances in photobiology and photodermatology have been enormeous. In the beginning, researchers investigated the relationship between SR and the skin. In 2002 a new concept, the systemic effects of SR, emerged. This concept complicates the understanding of photoprotection, because it implicates skin and other systems like endocrine and immune system. Actually, we know that ultraviolet radiation (UV) causes multifaceted damage to the skin and the adjacent tissues even systemic effects like immunesuppression. In this context, the photoprotection must be considered in both topical and systemic photoprotection.
There are a lot of topical filters (organic, inorganic and phytobiologic) that avoid deleterious effects of UV on the skin. The importance of filters toxicity concerns have been greatly exacerbated in recent years. The manufacturers of raw materials have been implemented various strategies in order to improve it effectiveness, stability, safety and ecotoxicity. In addition, there are several oral compounds, DNA repairers, vitamins and antioxidant molecules that will enhance SPF. However, some of these compounds need further investigations.
In this presentation we’ll show the findings on the tissue, cellular and molecular mechanisms underlying the photoprotective effects of Polypodium leucotomos extract and its efficacy in humans after oral and topical administration. Regarding the toxicity profile of Polypodium leucotomos, it has been shown that: 1) it’s non-mutagenic; 2) absence of oral acute toxicity results even at high doses of in both rats and mice; and 3) repetitive treatment has no long-term toxicity.
Polypodium leucotomos extract has demonstrated antioxidant properties (ROS quenching and lipid peroxidation), DNA protective activities (prevents formation of cyclobutane pyrimidine dimmers, inhibits basal oxidative damage marker [8-hydroxy-2’-deoxyguanosine] and blocks damage to mtDNA), anti-inflammation activities (prevents sunburn and erythema, blocks expression of TNFα, iNOS, AP-1 and NF-kβ, inhibits expression of COX-2 and prevents apoptosis) and immunemodulation activities (blocks t-UCA isomerisation, enhances natural antioxidant systems, prevents depletion of Langerhans cells and preserves their function).
Polypodium leucotomos combines extremely low toxicity with proven beneficial effects, even after oral administration. It has efficacy of various skin diseases such as vitiligo, psoriasis and polymorphous light eruption. It is clear that Polypodium leucotomos provides a very effective complement for sensitive skin phototypes and adds extra protection against UV radiation. Due to its photoprotective characteristics, Polypodium leucotomos extract also prevents photoaging and skin cancer induces by UV exposure.