The effects and mechanism of collagen peptide and elastin peptide on skin aging induced by D-galactose combined with ultraviolet radiation

The content of collagen and elastin occupies a large proportion of skin evaluation, and collagen peptide (CP) and elastin peptide (EP) are widely used drugs, which have anti-inflammatory effects. In addition, CP and EP can also be used as therapeutic agents for skin repair. However, previous studies have never thoroughly verified the effects of oral administration of CP and EP on skin repair. To study the effects and mechanism of oral administration of CP and EP on skin aging induced by combinatorial treatment with D-galactose and ultraviolet radiation. In animal experiments, the combined oral administration of CP and EP increased the contents of collagen and elastin in animal skin, accompanying with significantly upregulated expression of hyaluronic acid and hydroxyproline, as well as significantly reduced expression of MMP-3 and IL-1α. In addition, the combined therapy also significantly increased the expression of seven collagen and elastin synthesis-related factors including IGF-1, LOX, SMAD2, JNK, SP1, TβRII and TGF-β. Oral administration of CP and EP can repair skin aging induced by the combined treatment with D-galactose and ultraviolet radiation and the effects of CP and EP appeared synergistic.