Rationally Designed Nonapeptides with Great Skin Photoprotective Effect through Producing Type 1 Collagen and Blocking the mTOR Pathway

Ultraviolet
(UV), as the most common environmental stress
factor
to human skin, causes redox imbalance and leads to photoaging and
the development of cancer. In this work, we screened a nonapeptide
(PWH) with good activities of antioxidant, promoting the secretion
of type 1 collagen (COL-1) and repairing damaged skin from a series
of rationally designed novel short peptides. PWH could alleviate UV-A-induced
oxidative stress, restrain pro-inflammatory cytokine production, protect
mitochondrial function, and maintain autophagy activity. We also first
indicated that inhibiting the PI3K/AKT/mTOR signaling pathway and
restoration of autophagy activity might delay the photoaging process
in skin cells. Topical applications of PWH were further demonstrated
to exhibit significant protection in full-wavelength UV-induced skin
aging in mice models both in the prophylaxis and treatment way. In
addition, given the good stability and without unwanted toxicity and
anaphylaxis, PWH could be a promising candidate for cosmetics and
pharmaceuticals.