Autophagy is an evolutionarily conserved intracellular process of delivering cytosolic compartments into the lysosome for degradation. Physiological levels of autophagy induction are required for normal cellular functions, i.e., i) the elimination of aged, damaged organelles, and aggregated, excessive cellular proteins as well as pathogens, ii) regulation of apoptosis, differentiation, inflammation, and immunity in multiple cells/tissues, including skin. Whereas, dysfunction of autophagy mechanism is known to influence the pathogenesis of diverse human disorders, including skin aging

Aquatide 5000, pyrrolidone carboxylic acid (PCA) mimic peptide analogue, activates SIRT1, which then stimulates autophagy induction through deacetylation of FOXO1, leading to attenuation of UV-irradiation-mediated increase in cellular senescence and skin aging. These results indicate that SIRT1-autophagy axis is a key, considerable determinant in the regulation of skin aging. Additionally, Aquatide 5000 enhances skin barrier function through enhancing of ceramide synthesis and keratinocyte differentiation.