Masayuki Yagi
Anti-Aging Medical Research Center and Glycative Stress Research Center, Faculty of Life and Medical Sciences,Doshisha University, Kyoto, Japan
Masamichi Ishigami
Development Laboratory, SEPTEM-SOKEN Co., Ltd.,
Ryota Mori
Development Laboratory, SEPTEM-SOKEN Co., Ltd.,
Kaori Ishizaki
Anti-Aging Medical Research Center and Glycative Stress Research Center, Faculty of Life and Medical Sciences,Doshisha University, Kyoto, Japan
Riko Mitsuhashi
Anti-Aging Medical Research Center and Glycative Stress Research Center, Faculty of Life and Medical Sciences,Doshisha University, Kyoto, Japan
Wakako Takabe
Anti-Aging Medical Research Center and Glycative Stress Research Center, Faculty of Life and Medical Sciences,Doshisha University, Kyoto, Japan
Yoshikazu Yonei
Anti-Aging Medical Research Center and Glycative Stress Research Center, Faculty of Life and Medical Sciences,Doshisha University, Kyoto, Japan

[Abstract]
Accumulation of advanced glycation end products (AGEs) in skin, which is caused by glycative stress, is involved in the decline of elasticity and texture of skin. OPH degrades oxidized and glycated proteins and contributes to the proteolysis and reduction of aged proteins in cooperation with proteasome. However, OPH effects on AGEs have not been verified. This study explored the existence and non-existence of activity of OPH in stratum corneum and to verify the effects of OPH on AGEs, focusing on age-related glycation of skin tissue and defensive mechanisms towards glycative stress.
OPH-like activity was recognized in stratum corneum extract of cheek and inside upper arm. As a result of gel filtration chromatography analysis, where an extracted solution of cheek stratum corneum and OPH were fractionated, OPH-like activity was recognized in the same elution fraction. When Advanced Glycation End Product-modified Human Serum Albumin (AGE-HSA) was used as substrate and OPH was reacted, OPH decreased the amount of fluorescent AGEs in AGE-HSA and the amount of CML. As a result of reaction between extracted solution of cheek corneum and CML, the amount of CML in the reaction mixture was decreased. Measuring corneum OPH-like activity, amount of corneum CML and accumulation amount of skin AGEs, which were provided by 52 healthy females at age range from 21 to 75, negative correlation was shown between age and OPH-like activity. Positive correlation was shown between age and the accumulation of skin AGEs. Negative correlation was shown between corneum OPH-like activity and the amount of corneum CML and between corneum OPH-like activity and the accumulation of skin AGEs.
It may be possible that OPH-like activity, as existence was recognized in stratum corneum, was involved in proteolysis of stratum corneum CML and skin AGEs. It was indicated that the decline of stratum corneum OPH-like activity could be involved in an increase in the amount of stratum corneum CML and the accumulation of skin AGEs.