1142 Innovative oil-soluble biomimetic hexapeptide to fight UV damages

Abstract

Acute exposure to UV radiations results in erythema, immune suppression and cell death, while chronic exposure results in photoaging and carcinogenesis. In order to fight UV-induced skin damages, we have developed an oil-soluble form of an α-MSH biomimetic peptide. The binding of α-MSH to its melanocortin-1 receptor (MC1-R) induces epidermal pigmentation, which in turn activates the signal transduction pathway leading to the induction of melanin synthesis. In addition, it has been proven that α-MSH directly reduces UV-induced DNA damage and enhances DNA repair in epidermal melanocytes and keratinocytes, by modulating the function of DNA repair molecules. The objective of this study was to investigate whether a biomimetic peptide analogue of α-MSH, acetyl hexapeptide-1, was able to stimulate the natural skin defense system against sun exposure. We demonstrated in vitro that acetyl hexapeptide-1, acts effectively and simultaneously on melanogenesis to improve natural cell UV protection by melanin, on DNA protection (Comet assay, reduction in 8-oxo-dG) and repair (decrease in sunburn cells, caspase-3 activity and pyrimidine dimers) to limit photoaging and on the inflammatory cascade to soothe sun-ravaged skin (IL-1α, IL-8, PGE2 ). Clinically this biomimetic peptide demonstrated its efficacy on the increase in skin pigmentation and anti-erythemal properties after 14 days skin application showing a significant increase (+20%) of the Minimal Erythemal Dose compared to placebo. Furthermore, we developed a smart lipophilization technology (transparent w/o microemulsion) in order to improve the peptide diffusion through the Stratum corneum and allow its introduction in clear oil-based products.Especially designed to be introduced in oil-based products, this peptide represents the biological solution to improve sun care and anti-aging product efficacy in order to limit sun-induced premature aging.