Host: The Japanese Society of Toxicology
Name : The 49th Annual Meeting of the Japanese Society of Toxicology
Date : June 30, 2022 - July 02, 2022
A reactive oxygen species (ROS) assay is an in chemico photoreactivity test listed in ICH S10 guidance and OECD TG495. We currently utilize the ROS assay to assess photosafety of cosmetic ingredients, and we recently confronted a problem that there was an increase of blank absorbance assessing superoxide anion after irradiation. We found that the solvent DMSO was the main cause and 0.1μM of Cu2+ supplementation to the phosphate buffer (NaPB) was determined as being able to suppress blank absorbance increases1). However, DMSO is supposed to be added to the reaction mixture in a ROS assay even when the test chemical is prepared in NaPB. In addition, Cu2+ is a superoxide anion scavenger and thus development of the test system without using DMSO is desired. In this study, we report results of ROS assay using widely used solvents such as ethanol, isopropanol, acetonitrile or acetone.
1) Ohtake and Hirota, 2022. J. Toxicol. Sci. 47, 109-116.
