Establishment of in vitro methods for predicting chemical leukoderma caused by whitening agents in cosmetics.

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K00766
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Home economics/Human life
• Research Institution: Tokyo University of Technology
• Principal Investigator: MAEDA Kazuhisa 東京工科大学, 応用生物学部, 教授 (50454137)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 美白 / 白斑 / ヒドロキシラジカル / 皮膚内濃度

Outline of Final Research Achievements

Melanocytes cultured under conditions with high tyrosinase activity developed cytotoxicity when exposed to compounds known to cause leukoderma, while those cultured under conditions with low tyrosinase activity did not. Phenolic compounds that cause leukoderma were applied to melanocytes at the concentration to be absorbed percutaneously under conditions with high tyrosinase activity and they were observed under an electron microscope, demonstrating a large number of vacuolar degenerations in intracellular melanosomes for phenolic compounds known to cause leukoderma, but not for non-leukoderma-causing compounds. Subsequently, the generation of hydroxyl radical during tyrosinase reaction was examined, because whitening agents that inhibit tyrosinase activity serve as substrates for tyrosinase. As a result, phenolic compounds that cause leukoderma generated hydroxyl radical, while non-leukoderma-causing compounds did not.

Free Research Field

化粧品科学

Academic Significance and Societal Importance of the Research Achievements

本研究によって、過去に白斑を発生した化合物による白斑発症メカニズムは、過去に白斑を発生した化合物がチロシナーゼによってヒドロキシラジカル(・OH)が発生したため、メラノソームの破壊、さらにはメラノサイトの死滅によって引き起こされることが推察された。さらに、本評価系で白斑を引き起こすことがない他の美白有効成分と比較をすることによって、白斑を引き起こす可能性がある薬物かどうかを推測するin vitro 評価系として用いることができると考えられる。