Abstract
Action mechanisms underlying various biological activities of collagen peptides (CPs) remained to be elucidated. Cytokines may play an important role in mediating these health benefits of CPs. This study aimed to systemically examine the cytokines in skin and blood regulated by CPs intake. Thirteen-month-old female Kunming mice were administered with CPs for 2 months (0 or 400 mg/kg bodyweight/day). The cytokines in skin and plasma were analysed using a 53-cytokine array and corresponding ELISA kits. In skin, CPs intake significantly down-regulated placenta growth factor (PIGF-2), insulin-like growth factor (IGF)-binding protein (IGFBP) -2 and IGFBP-3, and up-regulated platelet factor 4 (PF4), serpin E1 and transforming growth factor (TGF)-β1 . CPs treatment also increased the type I collagen mRNA and protein levels and improved the aged skin collagen fibres. In plasma, nine cytokines were significantly down-regulated by CPs intake compared to the model group: fibroblast growth factor (FGF)-2, heparin-binding (HB) epidermal growth factor (EGF)-like growth factor (HB-EGF), hepatocyte growth factor (HGF), platelet-derived growth factor (PDGF)-AB/BB, vascular endothelial growth factor (VEGF), chemokine (C-X-C motif) ligand 1 (KC), matrix metalloproteinase (MMP)-9, interleukin (IL)-1α and IL-10; 2 cytokines were significantly up-regulated, including TGF-β1 and serpin F1. Furthermore, CPs intake significantly decreased the level of platelet release indicators in the plasma and washed platelets, including PF4, granule membrane protein (GMP)-140, β-thromboglobulin and serotonin. These results provide a mechanism underlying anti-skin ageing by CPs intake and highlight potential application of CPs as a healthcare supplement to combat cancer and cardiovascular disease by inhibiting platelet release.