Original paper
Influence of selected peptides and their copper complexes on antioxidant enzyme activities in human skin fibroblasts

Wrinkles in the skin are caused by degenerative changes in the proteins of the dermal extracellular matrix and by generation of reactive oxygen particles in skin cells. Stimulation of neosynthesis of these proteins in the dermis may result in improvement of wrinkles. Fibroblasts are responsible for new collagen and other protein synthesis in the dermis. There are many anti-wrinkle products, for example tretinoin or retinol, which improves fine wrinkles by increasing collagen production, but these compounds have irritating properties. Recently much attention has been focussed on the peptides and copper peptide complexes, which have good skin tolerance. These peptides were first described as cell growth factors but recent data suggested a physiological role related to the process of wound healing and tissue repair. Peptides such as Gly-His-Lys (GHK) may be used to stabilize and deliver copper into cells. As cosmeceuticals, copper peptides could improve skin firmness, fine wrinkles, and hyperpigmentation. They participate in collagen and elastin formation, downregulate matrix metalloproteinases, and reduce the activity of collagenase. Copper is a required cofactor for the enzyme superoxide dismutase (SOD), so it has antioxidant properties. The aim of the study was to evaluate the influence of selected peptides Gly-Gly-His, Gly-His-Lys and their copper complexes and water and Saccharomyces/copper ferment (Oligolides Copper®) on antioxidant enzyme activities and on proliferation of dermal fibroblast (NHDF) cell lines. The peptide fraction was responsible for increased fibroblast proliferation. Copper ions increase SOD activity twofold. Complexing properties of the peptides (in vitro) could be responsible for decreasing the available free copper ions fraction.