Host: The Japanese Society of Toxicology
Name : The 49th Annual Meeting of the Japanese Society of Toxicology
Date : June 30, 2022 - July 02, 2022
【Purpose】Keratin is the most abundant and cysteine-rich protein in human hair. This cysteine forms crosslinks keratin molecules via disulfide (R-SS-R’) bonds and its crosslinks generally believed to play the important role in toughness of hair. Recently, supersulfide such as R-SSH or R-SSS-R’ have been attracting attention, and It has been reported that supersulfide in proteins could affect not only structural flexibility, but also its antioxidant activity. However, the existence of supersulfide in hair keratin has been unclear. Herein, we measured the supersulfide in hair and evaluated their relationship to hair strength and antioxidant activity.
【Method】Supersulfide in hair was measured by elimination method of sulfide from polysulfide (EMSP). The hair was oxidized by after ultraviolet radiation or treatment with hydrogen peroxide, which is main component of decolorizing agents.
【Result and Discussion】The results of EMSP showed that the hair contains supersulfide, and oxidative stress such as ultraviolet radiation or hydrogen peroxide significantly reduced the supersulfide in hair. Interestingly, a high positive correlation was observed between supersulfide in hair and hair strength, suggesting that supersulfide in hair could protect the hair from various external factors such as ultraviolet radiation and function as one factor of hair homeostatic mechanism. The R-SSS-R’ crosslink structure, unlike R-SS-R’, could react with both reducing and oxidizing agent. Therefore, this study bring to the new perspective of stabilizing R-SSS-R’ crosslink to develop hair protectants.
