Anti-Wrinkle Benefits of Peptides Complex Stimulating Skin Basement Membrane Proteins Expression

Abstract

The dermal-epidermal junction (DEJ) provides a physical and biological interface between the epidermis and the dermis. In addition to providing a structural integrity, the DEJ also acts as a passageway for molecular transport. Based on the recently reported importance of the DEJ in skin aging, novel peptide derivatives have been tested for their effects on basement membrane (BM) protein expressions in cultured human epidermal keratinocytes. As a result, protein expressions of collagen XVII, laminin and nidogen were stimulated by the test peptide and peptides complex. Further ex vivo evaluation using excised human skin, confirmed that the topical application of the peptides complex significantly increased dermal collagen expression, as well as expressions of collagen XVII and laminin. Interestingly, while the origin of the laminin protein is epidermal keratinocytes, the immunohistochemical staining of skin showed that laminin was only detected in the uppermost layer of the dermis, which suggests a tight assembly of laminin protein onto the dermal side of the DEJ. These results suggest that a peptide complex could improve the structural properties of the DEJ through its ability to stimulate BM proteins. In order to evaluate the anti-wrinkle benefits of the peptide complex in vivo, a clinical study was performed on 22 healthy Asian female volunteers older than 40 years. As a result, significant improvements in skin wrinkles for all of the five sites were observed after two weeks, as assessed by skin topographic measurements. Collectively, these results demonstrate the anti-aging efficacy of the peptides complex.

Keywords: clinical efficacy; dermal-epidermal junction; laminin; nidogen; peptides complex; wrinkle.

Figure 1

Effects of the test peptides on basement membrane protein expressions in human epidermal keratinocytes. At high concentrations (200 ppm), increased expression of COLXVIIA1 and nidogen was observed in biotinyl hexapeptide (BH)- and biotinyl tripeptide (BT)-treated cells. Laminin expression was stimulated by BT and BH treatment in high (200 ppm) concentrations, while a slight increase of laminin was observed in low (50 ppm) concentrated ascorbyl succinyl tetrapeptide (AST).

Figure 2

Stimulation of collagen expression in cultured dermal fibroblasts and ex vivo skin tissue. Increased expression of collagen I by tested peptides was observed in cultured human dermal fibroblasts by enzyme-linked immunosorbent assay (ELISA) (a). Ex vivo skin tissue treated with tested peptides were stained by Masson’s Trichrome staining (b), showing significantly increased intensity in peptides complex treated tissue (c). (bar = 100 mm). (*: p < 0.05; **: p < 0.01; ***: p < 0.001).

Figure 3

Expressions of collagen XVII and laminin in ex vivo skin tissue. Increased expressions of collagen XVII in the basal layer of the epidermis by tested peptide complex was observed by immunohistochemical staining (a). Dermal expression of laminin was also increased by peptide complex treated tissue (b). (bar = 100 mm). Fluorescence intensity analysis using ImageJ showed significant increases in both 24 and 48 h of treatment for collagen XVII (c) and laminin (d). (***: p < 0.001).

Figure 4

Reduction of skin wrinkles by peptide complex treatment. Representative images of Antera 3D photographs after image processing. Significant improvements of skin wrinkles (arrows) were observed in Crow’s feet (a), nasolabial folds (b), glabella frown lines (c), horizontal forehead lines (d) and horizonal neck lines (e).