This research was carried out to: Test the effects of umbilical cord extracts on proliferation of human keratinocyte and activity of enzyme responsible for melaline production of human melaninocyte in vitro. | Journal of military pharmaco-medicine 7-2013 EFFECTS OF UMBILICAL CORD EXCTRACTS ON PROLIFERATION OF HUMAN KERATINOCYTE AND EXPRESSION OF TYROSINE KINASE GENE OF MELANINOCYTE IN VITRO Phan Kim Ngoc*; Pham Van Phuc*; Dang Thi Tung Loan* Dinh Thanh Uyen**; Le Van Dong*** summary 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 of preparation 3-5 containing a combination of both extra- and intra-cellular extracts of umbilical cord led to the highest cell proliferation of k eratinocyte. 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. * Key words: Skin aging; Skin softening; Skin brightening; Stem cell; Umbilical cord extract. INTRODUCTION Skin aging is known to be caused mainly by exposure to light, mostly .