Protective Effects of a New Human Placental Extract Against Hair Graying and Chemotherapy-Induced Peripheral Neuropathy

As stem cell therapy in regenerative medicine becomes more socially accepted, human perinatal tissue is attracting attention as a source because it can be harvested non-invasively. Human placental extracts (HPEs), which are prepared using acid hydrolysis and autoclaving, have been approved for treating menopausal disorders and liver dysfunction. This study investigated a new HPE formulation prepared under milder conditions by omitting acid hydrolysis and autoclaving to improve its effectiveness. The new HPE contains relatively high-molecular-weight proteins, including high levels of thioredoxin-1, as well as primarily extracellular matrix proteins such as thrombospondin-1. These proteins appear to be intact or partially fragmented, but they can still potentially maintain their domain structure. The HPE showed both antioxidant and neurite outgrowth activities in a neuronal cell line SH-SY5Y. In a mouse model of hair graying caused by X-ray irradiation, multiple administration of the HPE significantly reduced it. Additionally, the HPE, but not heat-inactivated HPE, alleviated the mechanical allodynia in a mouse model with chemotherapy-induced peripheral neuropathy. Due to the fact that HPE can be produced non-invasively in large quantities in a short time without the need for culturing, the new HPE may have the potential to be an effective and feasible therapy via multiple mechanisms.