1995 年 29 巻 2 号 p. 133-145
With the purpose of clarifying the role of internal factors in the process of dry skin occurs, dry skin was induced experimentally by an ionic surfactant and, using the model system, we investiglated from a pharmacological perspective as a new experimental plan. Through this research, we have conceived a new theory explaining how dry skin occurs. Furthermore, on the beais of this theory, we have developed a new effective compound for its treatment.
In order to study on the mechanism by which dry skin occurs, we used anti-inflammatory agents and inhibitors against histological impairment mediators, as well as various substances that were considered to regulate the function of epidermal cells. The results strongly suggested that the occurence of dry skin involves a cause bringing about the over-manifestation of the epidermal plasminogen (PLG) activation system, which in turn causes abnormalities in the regulating mechanisms for the proliferation and differentiation of epidermal cells, and these result in dry skin.
We discovered 4-aminomethylcyclohexanecarboxylic acid (t-AMCHA), which was the most effective substance in view of the theory on the occurrence of dry skin. Then we investigated in detail the efficacy of t-AMCHA. The results of our studies confirmed that t-AMCHA strongly suppresses the over-manifestatation of the PLG activation system in the epidermis when dry skin was occurring. In addition, t-AMCHA demonstrated superb effectiveness against phenomena caused by dry skin, including the loss of moisture from the horny layer, the increase in transepidermal water loss (TEWL), accelerated turnover in the horny layer, and the changes in various other indicators such as epidermal hypertrophy.
We also performed a double-blind trial on a preparation containing t-AMCHA. Results demonstrated that the preparation containing t-AMCHA definitely made better and faster improvement than the preparation without t-AMCHA in skin surface texture. Furthermore, the t-AMCHA containing preparation showed superior stability and safety and had excellent usability.
We demonstrated for the first time that the intraepidermal PLG activation system plays a major role in the process by which dry skin occurs, and founded a new theory on the occurrence of dry skin. In addition, on the basis of this theory, we discovered the effective substance t-AMCHA and conducted research on its practical application. As a result, we have not only verified the theory but also developed a revolutionary new effective substance for cosmetics.