LAUSR

Ultraviolet radiation (UV‐R) causes genotoxic and aging effects on skin, and sunscreens are used to alleviate the damage. However, sunscreens contain synthetic shielding agents that can cause harmful effects in the environment. Nature‐derived substances may have potential as replacement materials for the harmful sunscreen chemicals. However, screening of a broad range of samples is tedious, and often requires a separate genotoxicity assessment. We describe a simple microplate technique for the screening of UV protective substances using a recombinant Escherichia coli biosensor. Both absorbance‐based and bioactivity‐based shields can be detected with simultaneous information about the sample genotoxicity. With this technique, a controversial sunscreen compound, oxybenzone offers physical or absorbance‐based shield but appears genotoxic at higher concentrations (3.3 mg/mL). We also demonstrate that pine needle extract (PiNe) shields the biosensor from UV‐R in a dose‐dependent manner without showing genotoxicity. The physical shield of 5 mg/mL PiNe was similar to that of one of the most common UV‐shielding compound TiO2 concentration 0.80 mg/mL. The bioactivity‐based shield of PiNe also reaches the extent of the physical shield with the highest concentration (3.3 mg/mL). We conclude that our technique is suitable in detecting the UV‐shielding potential of natural substances, and gives simultaneous information on genotoxicity.