Use of soluble forms of the Desmoglein I protein for the purposes of screening for anti-ageing active agents

A method for characterizing the effectiveness of a cosmetic treatment intended, in an individual having an epidermis showing one or more signs of skin ageing, to compensate the accumulation of desmoglein I in the stratum corneum, the method comprising:

• a) after administering the cosmetic treatment, obtaining a skin sample from the individual;
• b) quantifying at least one soluble peptide form with an anti-desmoglein I antibody, wherein the soluble peptide derives at least in part from the proteolysis of a polypeptide comprising an amino acid sequence represented by part of SEQ ID NO:2;
• and
• c) comparing the content obtained in step b) with a reference value obtained from a cosmetically untreated skin sample, and the presence or increase in the soluble peptide form content with respect to the reference value being indicative of a release of desmoglein I from the stratum corneum, and said release of desmoglein I being indicative of an effectiveness of the cosmetic treatment.