Method of evaluating skin barrier function, method of screening material for enhancing skin barrier function using the evaluating method, the material for enhancing skin barrier function, and cosmetic containing the material for enhancing skin barrier function

Abstract

A method for developing an excellent material for enhancing skin barrier function, and providing a cosmetic which is developed based on the method and has excellent ability to enhance skin barrier function is described. The method evaluates skin barrier function by the steps of 1) culturing normal human epidermal cells in wells having a semipermeable membrane with two sides, in presence and absence of a test substance; 2) adding a medium not containing metal ions to a first side of the semipermeable membrane in each well and a medium containing the metal ions to a second side of the semipermeable membrane in each well, provided that the cells are adhered to the first side of the semipermeable membrane; 3) culturing the cells; 4) measuring the concentration of the metal ions in each medium; and 5) calculating permeability of the metal ions in the epidermal cell layer based on the measured concentrations of the metal ions in each media. The test substance is effective for enhancing skin barrier function when the permeability is reduced in the medium in which the test substance is added compared to the permeability in the medium in which no test substance is added. The larger the level of reduced permeability, the higher the suitability of the test substance as a material for enhancing skin barrier function.

1 . A method of evaluating skin barrier function using permeability of metal ions through an epidermal cell layer as an index, comprising:
 determining permeability of metal ions through an epidermal cell layer, and   evaluating the permeability of the metal ions, wherein the higher the permeability of the metal ions, the lower the skin barrier function.   
   
   
       2 . The method of evaluating skin barrier function according to  claim 1 , wherein the metal ions are calcium ions and/or magnesium ions. 
   
   
       3 . A method of screening material for enhancing skin barrier function, comprising:
 1) culturing normal human epidermal cells in wells comprising a semipermeable membrane with two sides, in presence and absence of a test substance;   2) adding a medium not containing metal ions to a first side of the semipermeable membrane in each well and a medium containing the metal ions to a second side of the semipermeable membrane in each well, provided that the cells are adhered to the first side of the semipermeable membrane, and the second side is opposite thereto;   3) culturing the cells;   4) measuring a concentration of the metal ions in each medium; and   5) calculating permeability of the metal ions in the epidermal cell layer based on the measured concentrations of the metal ions in each media, wherein the test substance is effective for enhancing skin barrier function when the permeability is reduced in the medium in which the test substance is added compared to the permeability in the medium in which no test substance is added, and evaluating that the larger the level of reduced permeability, the higher the suitability of the test substance as the material for enhancing skin barrier function.   
   
   
       4 . The method of screening material for enhancing skin barrier function according to  claim 3 , wherein the metal ions are calcium ions and/or magnesium ions. 
   
   
       5 . The method of screening material for enhancing skin barrier function according to  claim 4 , wherein the metal ion is calcium ion. 
   
   
       6 . A material for enhancing skin barrier function, which is judged to be effective by the method according to  claim 3 . 
   
   
       7 . An adjuster for calcium ion in epidermis, comprising the material for enhancing skin barrier function according to  claim 6 . 
   
   
       8 . A cosmetic comprising the material for enhancing skin barrier function according to  claim 6 . 
   
   
       9 . A material for enhancing skin barrier function, which is judged to be effective by the method according to  claim 4 . 
   
   
       10 . An adjuster for calcium ion in epidermis, comprising the material for enhancing skin barrier function according to  claim 9 . 
   
   
       11 . A cosmetic comprising the material for enhancing skin barrier function according to  claim 9 . 
   
   
       12 . A material for enhancing skin barrier function, which is judged to be effective by the method according to  claim 5 . 
   
   
       13 . An adjuster for calcium ion in epidermis, comprising the material for enhancing skin barrier function according to  claim 12 . 
   
   
       14 . A cosmetic comprising the material for enhancing skin barrier function according to  claim 12 .