Mann T, Eggers K, Rippke F, et al. - Given that solar radiation causes skin damage through the generation of reactive oxygen species (ROS), researchers conducted this investigation to examine VIS-induced ROS formation and the photoprotective effects of the nuclear factor erythroid 2-related factor 2 (Nrf2) inducer Licochalcone A (LicA), extracted from the roots of Glycyrrhiza inflata. According to results, dose-dependently induced visible spectrum of 400-500 nm of ROS in cultured human fibroblasts at doses equivalent to 1 hour of sunshine on a sunny summer day (150 J/cm²). A 24-hour pretreatment with 1 μmol/L LicA reduced ROS formation to the level of unirradiated cells while UV filters alone, even at SPF50+, were ineffectual. In vivo, topical treatment with a LicA-containing SPF50 + formulation significantly prevented the depletion by VIS irradiation of intradermal carotenoids while SPF50 + control did not protect. Findings suggested that LicA can be a beneficial additive antioxidant for sunscreens.