Abstract
Skin aging in humans is complex and is induced by internal and external factors. Studies have pointed towards biological processes including alterations in DNA repair and stability, mitochondrial function, cell cycle and apoptosis, ubiquitin-induced proteolysis, and cellular metabolism dysfunction. Untargeted metabolomics is key to better characterize and understand biological processes involved in (accelerated) aging at the level of multiple organ and tissues. Characterize metabolic changes in relation to human skin aging and explore if/how an extract from dessication tolerant medicinal herb, Myrothamnus flabellifolia, could affect skin aging and related metabolites. We evaluated clinical characteristics and untargeted metabolomic profiles of the skin of 32 individuals both before (D0) and after (D56) the application of a specific formulation containing extract from M. flabellifolia. Using conditional independence networks we explored how the formulation affected the correlation structure amongst skin metabolic features. Using an MWAS approach, we explored which molecular features were (i) dysregulated at the end of the experiment, and (ii) associated with changes in clinical characteristics during that period. Our analyses indicated clear metabolic changes and clinical improvement of skin radiance and texture after 56 days of treatment. Of the 419 assayed metabolites, 109 were either dysregulated at D56 or associated with at least one clinical sign. Of these, 12 compounds were detected in the green gel or red powder, the two active components of the extract, in particular trehalose, which was detected in both the green gel and the red powder. Collectively, this study demonstrates biochemical changes after application of the active formula, suggestive of its embodiment. Changes in the skin metabolome associated with the clinical signs we assayed helps hypothesizing molecular pathways involved in improvement of skin quality and aging signs.