610 Development of a natural product-based sunscreen

Sunscreens are a cornerstone of skin cancer prevention; however, currently available sunscreens have limitations. Concerns regarding current organic sunscreen agents include photodegradation, potential disruption endocrine pathways, and paradoxical generation damaging reactive oxygen species (ROS). Recent studies by the FDA shown that permeate into systemic circulation at levels warranting further safety testing, highlighting importance investigating alternative strategies for safe effective photoprotection. Towards this goal, we previously conducted high-throughput screening natural compounds photoprotective potential, quantifying UV spectral absorbance, photostability, cytotoxicity, ROS generation. From pilot set 915 compounds, prioritized 11 candidates interest confirmatory photostability testing follow-on in vitro SPF 5wt% P2 formulation. Top performers were diosmin (DIO; 2.7), isoliquiritigenin (IQL; 2.5), ferulic acid (FA; 3.1), cytisine (CYT; 6.3). To create broad-spectrum formulation, these assessed individually combination critical wavelength (λcrit), vivo C57BL/6J mice protection against ultraviolet radiation (UVR)-induced cyclobutane pyrimidine dimer (CPD) formation irritant contact dermatitis potential. 10% DIO + FA 5% CYT was best performer our test combinations, with mean 48.6 (SD 3.2), λcrit 373, 92.4% CPDs blocked 3.5%). Other promising combinations utilizing varying concentrations or IQL also demonstrated λcrit>370 SPF>15, i.e. minimum requirements decreasing risk cancer. None induced as gross histologic examination after 5 repeated applications to shaved dorsal every 2 days. Collectively, data demonstrate proof concept high throughput method identifying candidate toward formulation product-based sunscreen.