The Effect of Cosmetic Ingredients of Phenol Type on Immediate Pigment Darkening and Their (Photo)Protective Action in Association with Melanin Pigmentation: A Model In Vitro Study

Immediate pigment darkening, the first response of skin to solar exposure leading undesired irregular pigmentation and dark spots, is rapid onset melanin resulting from oxidation melanogenic indoles, namely 5,6-dihydroxyindole (DHI) 5,6-dihydroxyindole-2-carboxylic acid (DHICA) available in epidermal melanocytes. The search for effective sunscreen formulations nowadays focused on UVA/B filters additional ingredients that may scavenge reactive oxygen species generated these processes. In this work effects phenolic cosmetic (CIs), paradol-6, a ginger CO2 extract, phenylethyl resorcinol photosensitized DHI DHICA were investigated showing decrease their consumption formation (25–30% with resorcinol). photoprotective role CIs was also evaluated model systems. Paradol-6 extract can halve linoleic peroxidation riboflavin-sensitized reaction, while dienes generation reduction (30% control) observed Rose-Bengal-sensitized photooxidation paradol-6. presence DHI/DHICA exerted synergistic effect. decay thymine free or as DNA base almost completely inhibited by CIs. These results open new perspectives design care ameliorating spots contrasting ageing processes associated sun exposure.