Anti-senescence effect of acetyl dipeptide-1 cetyl ester on skin and its mechanism

Acetyl dipeptide-1 cetyl ester (AD-1) is a synthetic peptide composed of acetic acid and cetyl alcohol with arginine and tyrosine, which has certain anti-inflammatory and skin barrier enhancement effects, has been used in cosmetics for sensitive skin.Meanwhile, the ingredient has also been used in anti-aging cosmetics, but there is a lack of published scientific evidence on anti- senescence aspect.In this study, we investigated the related effects of AD-1 by evaluating its in vitro antioxidant and antiglycation efficacies.Furthermore, we established a photoaging model on primary rat dermal fibroblasts by repeated exposures to UVA irradiation.MTT assay was used to detect the effects of AD-1 on the cell viability.RT-qPCR was used to determine the effects of AD-1 on the mRNA levels of senescence-related p21, p53, MMPs, IL6, Col1, Col3 and autophagy-related p62, ATG5, ATG7.Western blot was used to detect the effects of AD-1 on the protein levels of p16, p21, p53, Col1, LC3B and p62.SA-β-gal was performed to indicate senescence level of the cell.MDC was performed to indicate autophagy level.Intracellular reactive oxygen species were monitored by fluorescent probes DCFH-DA.The results showed that AD-1 could reduce UVA-induced the cell damage and regulate the abnormal expression of mRNA levels. It alleviated the abnormal protein levels of p16, p21, p53, Col1, LC3B and p62 induced by UVA. These results suggested that AD-1 has not only antioxidant and antiglycation effects but also can activate autophagy to achieve anti-senescence effect.