Beauty and cosmetics revolve around one organ: the skin. For more than thirty years, L’Oréal has been committed to the in-depth study of the skin through a multidisciplinary approach that brings together biological, in vitro and clinical studies. Until now, the study of how skin ages relied on biophysical and morphological methods. But no more. Tissue is composed of cells that, at the center of chromosomes, host some 25 to 30 thousand genes identified in humans. Each gene is directly in charge of a biological property.
Using the tools of molecular biology, L’Oréal researchers have been able to penetrate deep inside cells, obtaining the keys to understanding their workings and make-up.
With age, it is not our genes that get older, since genetic material does not age. Rather, it is the dermis and epidermis that gradually deteriorate. But why? Slow cell renewal? Local inflammation? A reduced ability for regeneration? Different cases yield different answers, which encourage the development of new active ingredients designed to give skin back its youthful appearance.
First and foremost, transcriptomic studies have shown that the surface of the epidermis has a double response to exfoliation of both young and old skin.
In older subjects, 382 genes modified their expression level within the first 72 hours of epidermal repair; in younger subjects, this was true for 370 genes. Therefore, 198 genes are specific to older skin while 186 are specific to younger skin. Additionally, older skin repairs itself more slowly than younger skin.