Evaluation of Skin Photo-stress Using Catalase

Abstract

In order to develop an evaluating method of photo-stress of skin, we have been investigating a methodology to analyse catalase activity derived from stratum corneum (skin catalase activity) as a biomarker. The objective is to demonstrate the usefulness of skin catalase activity as an index of photo-stress by compairing the cheek and the upper arm in 61 female adults. The stratum corneum was collected by tape stripping, concentrating stratum corneum sample solution and using a fluorescent substrate of skin catalase activity. The skin catalase activity ranged between 1.18 and 223 U/cm² in all of the stratum corneum samples in the subjective evaluation. It was indicated that this analysis method had a sufficient range for the analysis of skin catalase activity. The significant correlation was observed between the skin catalase activity /total protein (TP) ratio and the skin color parameter (skin color: a^*, r =0.54; b^*, r = -0.44). Therefore, it was considered that the skin catalase activity /TP ratio might be a useful index of the skin condition for humans.