The anti-aging effect and mechanism of a compound peptide on sensitive skin

Background Sensitive skin is characterized by symptoms of discomfort when exposed to environmental factors. Peptides are incorporated into cosmetics for sensitive skin due to their ability to interact with skin cells through multiple mechanisms. Objectives To investigate the anti-inflammatory and repairing effects of a novel complex peptide with the main components of palmitoyl pentapeptide-4, acetyl hexapeptide-8, acetyl tetrapeptide-11, β-alanyl hydroxyproline diaminobutyric acid benzylamine, and decarboxylated carnosine peptide in the TNF-α-induced sensitive skin model, and its collagen synthesis effect in the 3D whole-layer skin model after Ultraviolet A (UVA) irradiation. Methods Interleukin-1α (IL-1α), IL-6, IL-8, and PGE2 levels were determined using ELISA. NF-κB, FLG (Filaggrin), LOR (Loricrin), Claudin1, Collagen I∼XVII, and HABP levels were examined by immunofluorescence. Ki67 expression and cell viability were determined using immunohistochemistry and MTT. Malondialdehyde (MDA), reactive oxygen species (ROS), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) levels were assessed using kits. p21 and p16 levels were detected using qRT-PCR and western blot. Results In the TNF-α-induced sensitive skin model, NF-κB (2.68 vs 1.78), IL-1α (3.86 vs 1.10), IL-6 (3.61 vs 2.29), IL-8 (22.74 vs 11.78), and PGE2 (55.85 vs 19.19) levels were decreased by complex peptide addition, while FLG (0.38 vs 0. 06), LOR (0.53 vs 0.09), Claudin1 (0.38 vs 0.95), and Ki67 (13.10 % vs 3.32 %) levels were increased. In a 3D whole skin model after UVA irradiation, complex peptide addition resulted in increased levels of Collagen I (0.34 vs 0.87), Collagen III (0.41 vs 0.88), Collagen IV (0.35 vs 0.87), Collagen V (0.48 vs 1.30), Collagen VII (0.52 vs 1.42), Collagen XVII (0.42 vs 1.43), and HABP (0.54 vs 1.54), and a decrease in factors associated with oxidative stress and aging. Conclusion Preliminary in vitro experiments indicate that this complex peptide can have an anti-aging effect in model systems by strengthening the skin barrier, reducing inflammation and photo-aging, increasing the content of hyaluronic acid in the skin, and promoting collagen synthesis in the dermis.