New Strategies of Photoprotection

Abstract

Adequate photoprotection is essential to control UV-related disorders, including sunburn, photoaging and photocarcinogenisis. Sun avoidance, protection of skin with clothing, and sunscreens are presently the best way of photoprotection, assuming that they are used properly. However, new strategies, which are based on or make use of the endogenous protective response to UV light, may further improve currently used photoprotective means. The addition of repair enzymes and/or antioxidants has a positive effect on skin's recovery from UV-induced DNA-damage. Several botanical agents, mainly vitamins and polyphenols, have shown to influence signal transduction pathways leading to photoprotective effects. Also stimulation of endogenous UV-response pathways via irradiation with a low UV dose or via simulation of UV-induced DNA-damage results in photoprotective effects. Future research in this field and combination of different photoprotective strategies will hopefully lead to improved photoprotection.

Topical Formulations Containing Pimenta pseudocaryophyllus Extract: In Vitro Antioxidant Activity and In Vivo Efficacy Against UV-B-Induced Oxidative Stress

“…Epidemiological studies indicate that the use of sunscreens and sun blockers are not completely effective in preventing UV irradiation-induced skin cancer (4-6), thus, new targeted chemopreventive approaches need to be identified (7). Considering the deleterious effects of ROS in the skin, many studies have focused on the establishment and evaluation of antioxidants to enrich the endogenous cutaneous protection system, and to prevent and/or treat UV irradiation-induced skin damage.…”

Antioxidant Defense and UV-Induced Melanogenesis: Implications for Melanoma Prevention

“…Antimelanogenic effects of natural antioxidants (Table 1), phytochemicals (Table 2) and botanicals processing antioxidant properties (Table 3) have been intensively explored in a variety of preclinical in vitro cell culture and animal models as well as clinical trials (GomezCordoves et al 2001;Saikia et al 2006). Phytochemicals including phenolics and essential oils, usually identified as active ingredients in botanicals, are capable of scavenging ROS/ RNS and inhibiting cellular oxidative stress and thus might be responsible for the pharmacological effects of the plant extracts (Verschooten et al 2006;K.H. Wang, 2006).…”

Lonicera caerulea and Vaccinium myrtillus fruit polyphenols protect HaCaT keratinocytes against UVB-induced phototoxic stress and DNA damage

“…Solar UV radiation at the earth's surface comprises approximately 90-99% UVA and 1-10% UVB [2]. Middle-wave UVB light (280-315 nm) is largely absorbed (95%) in the protective ozone layer.…”

“…Direct absorption of UVB photons leads to disruption of DNA, with cyclobutanepyrimidine dimers and pyrimidine-pyrimidone (6-4) photoproducts as a result. UVB photons also directly interact with aromatic amino acids, mainly tryptophan and tyrosine, in proteins and their modification may alter protein function [2]. UVB also participates in indirect damage to macromolecules.…”