Oxothiazolidine, a Skin Penetrating Active Ingredient Offering a New Approach to Photoaging Prevention

摘要

Oxothiazolidine is an antioxidant molecule that combines reactive oxygen species scavenging and reactive car-bonyl species scavenging including oxidative stress downstream products scavenging. Interestingly, oxothiazolidine has the unique property to form taurine, an amino acid naturally present in the skin, upon reaction with some reactive oxygen species. Interest in the use of oxothiazolidine for photoaging prevention was addressed because reactive oxygen species formation is primarily responsible for ultraviolet radiation-mediated photo-damage. Since deeply penetrating ultraviolet wavelengths such as UVA may generate reactive oxygen species in deep layers of the skin, the oxothiazolidine bioavailability was determined. Here, we show that oxothiazolidine crosses the stratum corneum to access viable layers of the epidermis and permeates into the dermis, enabling deep-sited sea venging of re-active oxygen species (and their byproducts). The photoprotective properties of oxothiazolidine were studied in vitro in a three-dimension model and ex vivo in human skin ex-plants. Immunohistological studies have shown that topical oxothiazolidine limits UVB-induced apoptosis in the epidermis and UVA-induced inflammation (monitoring of cyclooxy-genase isoform 2 expression in the dermis). Oxothiazolidine preserved collagen VII in the dermal-epidermal junction and decorin expression in the dermis after UVA irradiation, thus confirming its ability to protect deep-sited targets from oxidative stress. Production of matrix metalloprotei-nase 1, a major collagen-degrading enzyme activated by UVA, was also reduced by oxothiazolidine treatment. Taken together, these results strongly support the usefulness of oxothiazolidine for topical photopro-tection.