Evaluation of fibroblast growth factor activity exerted by placental extract used as a cosmetic ingredient.

BACKGROUND: The biological activities claimed for placental extract (PE) in its medical and cosmetic applications are largely assumed to be the combined effects of its various signaling molecules and nutritional constituents. But there are considerable uncertainties about this assumption. AIMS: To determine the specific biological activity of PE at a molecular level. METHODS: Fibroblast growth factor (FGF) activity was assessed based on the ability to induce proliferation of FGF receptor (FGFR)-overexpressing BaF3 cells. RESULTS: Porcine PE (PPE), an ingredient in numerous cosmetics, activated proliferation of BaF3 cells overexpressing FGFR subtypes 1c, 2c, 2b, 3c, or 4, that is, all the major FGFR subtypes. The effect was suppressed largely or partially when the cells were treated with a FGFR inhibitor PD173074, and the FGFR-negative BaF3 parent cells exhibited minimal growth promotion as compared to the FGFR-expressing BaF3 cells. The high (>10 kDa) and low (<3 kDa) molecular weight fractions of PPE were effective activators of FGFR signaling. PPE was found to contain sulfated glycosaminoglycans, including heparin/heparan sulfate and chondroitin sulfate, which serve as both structural stabilizers of FGFs and indispensable cofactors for FGF-FGFR signaling. CONCLUSIONS: These results indicate that PPE is capable of evoking FGF signaling in cells via FGFRs. Given that recombinant FGFs have proven useful for medical/cosmetic purposes, our results suggest that the medical/cosmetic utility of PPE is provided at least partly through the activation of FGF signaling in epidermal, dermal, and subdermal tissues.