Surface rejuvenating effect of Achillea millefolium extract

Proopiomelanocortin is a precursor peptide that gives rise to several neuropeptides including adrenocorticotrophic hormone (ACTH) and β-endorphin. POMC-derived peptides have been shown to be synthesized in human epidermis where they modulate numerous skin functions. Because we previously observed that melanocortin receptor-2 and μ-opioid receptor 1, the respective receptors for ACTH and β-endorphin decreased with ageing in human epidermis, we have selected an active ingredient (INCI name: Achillea millefolium extract) able to upregulate receptor expressions. The aim of the present work was first to evaluate the effect of A. millefolium extract on the expression pattern of various epidermal differentiation markers ex vivo in normal human skin biopsies using quantitative image analysis and second to evaluate its capacity to rejuvenate the appearance of skin surface in vivo. Results show an improved expression profile of cytokeratin 10, transglutaminase-1 and filaggrin in cultured skin biopsies as well as an increased epidermal thickness. In vivo, a 2-month treatment with A. millefolium extract at 2% significantly improved the appearance of wrinkles and pores compared with placebo. Results were also directionally better than those of glycolic acid that was chosen as reference resurfacing molecule.