Effects of Light Sources on the Prediction of Phototoxicity by the Yeast Growth Inhibition Phototoxicity Assay and the Red Blood Cell Photohemolysis Assay

Masaaki Mori, Masatoshi Hoya, Mariko Sugiyama and Hiroshi Itagaki
Safety & Analytical Research Center, Shiseido Co., Ltd., 2-12-1 Fukuura, Kanazawa-ku, Yokohama-ski, Kanagawa 236-8643, Japan

Original paper :AATEX 10(1):1-17
The effects of different light sources on the prediction of phototoxic potential by use of the yeast growth inhibition phototoxicity (YGI PT) assay, the red blood cell photohemolysis (RBC PH) assay and a battery system of the two were investigated using twenty-four cosmetic ingredients. The optimal conditions for the use of a solar simulator were determined in order to obtain the best possible correlation with the in vivo data. The results of evaluation with the use of the solar simulator and the previously reported results with the use of a UVA irradiator were compared with in vivo guinea pig phototoxicity data, and the correlation between in vivo and in vitro results was calculated. The battery system showed relatively high values of correlation parameters. There were no marked differences between the values obtained with the use of the solar simulator and the UVA irradiator. The parameters in the battery system were also similar to those obtained with the 3T3 neutral red uptake phototoxicity assay employed in the EU/COLIPA validation study. These results suggest that the solar simulator is applicable for the YGI PT assay, the RBC PH assay and the battery system, and this battery system was concluded to be useful to predict the phototoxic potential of chemicals.

Key words: Phototoxicity, solar simulaton; battery evaluation system, yeast growth inhibition test, photohemolysis