Cosmetic agent that induces expression of DOPAchrome tautomerase as a protective agent for hair follicle melanocytes in prevention and treatment of hair pigmentation loss

摘要

Cosmetic agent (I) that induces expression of DOPAchrome tautomerase comprising hexamethylene bisacetamide (HMBA), steroidal hormones such as diethylstilbestrol and/or estradiol, glycyrrhizin, forskolin, kaempferol, a modulator of an endogenous factor situated upstream from DOPAchrome tautomerase (TRP-2) or an expression vector coding for (TRP-2) or an expression vector coding for an inducer of expression of (TRP-2) such as Sox10, is new. Independent claims are also claimed for: (1) identifying an agent that induces expression of DOPAchrome tautomerase comprising the following steps: (a) culturing a population of melanocytes in a medium in which the melanocytes do not express the DOPAchrome tautomerase; (b) addition of a test compound to test the expression inducing activity of (I) in the culture medium; (c) incubating the melanocytes for a sufficiently long time so that the melanocytes can express the DOPAchrome tautomerase; (d) measuring the expression of DOPAchrome tautomerase; and (e) selecting the compounds that induce the DOPAchrome tautomerase expression; (2) identification (M1) of an agent that induces the activity of a promoter of DOPAchrome tautomerase (TRP-2) comprises: (a) construction of a plasmid vector comprising a promoter region of the DOPAchrome tautomerase gene situated upstream from a reporter gene; (b) transforming a population of cells with the plasmid vector obtained in (a); (c) adding a compound to be measured for its capacity to induce activation of the promoter of DOPAchrome tautomerase in the culture medium of one of the two populations of cells obtained in (b); and (d) selection of compounds inducing activity of the promoter of the DOPA chrome tautomerase (TRP-2) by comparison of the expression of the reporter gene in a population of cells obtained in step (c) and with expression of the reporter gene in a population of cells obtained in step (b) who has not been incubated with the test compound; and (3) evaluation (M2) of the cytoprotective activity of an agent that induces expression of the DOPAchrome tautomerase identified by the above method comprises: (a) culturing a population of melanocytes in a medium limiting expression of TRP-2 to a weak base level; (b) addition of a compound that induces expression into the medium; (c) incubation of melanocytes for a sufficiently long time to encourage expression of DOPAchrome tautomerase; (d) exposing the cells to a condition that induces apoptosis or senescence; (e) measuring cytotoxicity; (f) selecting the compounds that induce expression of DOPAchrome tautomerase identified by expression of a cytoprotective effect.