ảnh hưởng của chất chiết xuất từ dây rốn đến sự phát triển của keratinocyte của người và biểu hiện của gene tyrosine kinase trong điều kiện monocyte in vitro

Skin aging is a contuinuous process influenced by many factors such as free redicals, sun exposure etc. This process is characterized with changes in many skin components, primarily affected by three main cell types: fibroblast, keratinocyte and melaninocyte. Decreased number of keratinocytes leads to less soften skin; while increase or decrease melanine production will lead to imbalance of skin color leading to either: backhead or vitiligo. This suty evaluates the effects of umbilical cord exctracts on proliferation of human keratinocyte and melaline production of melaninocyte in vitro. 25 preparations made of 4 types of extracts included: extracellular exctract of cord tissue; intracellular extract of cord cells; mixtures of these two extracts; intracellular extract of umbilical cord stem cells, were supplemented to culture media of human skin keratinocyte and melaninocyte. Keratinocyte cell proliferation was evalutaetd by MTT technique; melanine production was indirectly evaluated via tyrosine kinase gene expression by Realtime RT-PCR technique. The results show that supplementation of 7.5 percent of preparation 3-5 containing a combination of both extra- and intra-cellular extracts of umbilical cord led to the highest cell proliferation of keratinocyte. However, at this concentration, the 3-5 preparation did not inhibite the expression of tyrosine kinase gene in melaninocyte. These data suggests that umbilical cord extract would be a potential source of material for skin softening product but not brightening one.