Effects of soybean peptide and collagen peptide on collagen synthesis in normal human dermal fibroblasts

The collagen present in the dermis of the skin is a fibrous protein that fills the gaps between cells and helps maintain tissue flexibility. Effectively increasing the collagen present in the skin is an important goal for cosmetic research. Recent research has shown that soybean peptide (SP) has anti-fatigue activity, antioxidant activity, and the ability to increase type I collagen, while collagen peptide (CP) has the ability to enhance corneal moisture content and viscoelasticity, as well as to increase levels of hyaluronic acid synthesizing enzymes in human skin. Little documented research, however, has been conducted on collagen formation in relation to these peptides. Therefore, this research applied SP and CP with molecular weights primarily around 500 and preparations containing both SP and CP to normal human dermal fibroblasts together with magnesium ascorbyl phosphate (VC-PMg), and used real-time PCR to determine the gene expression of type I collagen (COL1A1), which contributes to collagen synthesis, and Smad7, which contribute to collagen breakdown. In addition, enzyme linked immuno sorbent assay (ELISA) was used to measure collagen content in the media. COL1A1 gene expression at 24 h after sample addition showed higher tendency in all samples and increased with time at 4, 8 and 24 h after addition. Smad7 gene expression was not substantially different at 4 h after addition. matrix metalloproteinase-1 gene expression was higher following SP addition, but was lower after the addition of CP and SP + CP. Medium collagen content was higher in all samples and increased with time at 8 h after addition. Collagen levels were higher when SP and CP were added together.