title: Activity of Ginkgo biloba extract and quercetin on thrombomodulin expression and tissue-type plasminogen activator secretion by human umbilical vein endothelial cells.
abstract: OBJECTIVE
  In order to investigate the pharmacological properties of Ginkgo biloba extract (GBE) on improving blood circulation, the regulating action of GBE and quercetin (a main flavonoid ingredient in GBE) on thrombomodulin (TM) expression and tissue-type plasminogen activator (t-PA) secretion was studied.
  
  
  METHODS
  Using flow cytometer and gel image system respectively, we evaluated the TM expression and the t-PA secretion by human umbilical vein endothelial cells (HUVECs) in vitro.
  
  
  RESULTS
  The increase of TM expression on HUVECs surface was induced by GBE rather than quercetin in a dose- and time-dependent manner. Both GBE and quercetin increased the t-PA release significantly.
  
  
  CONCLUSIONS
  The effect of GBE on improving blood circulation may be partly attributed to its promoting TM expression and t-PA secretion by endothelial cells, and quercetin participated in the effect of GBE on t-PA secretion. However, the action of GBE on increasing TM expression needs further study.
authors.affiliation: Key Laboratory for Biomedical Engineering of Ministry of Education of China, Zhejiang University (Yuquan Campus), Hangzhou 310027, Zhejiang, China. lanwenjun0522@hotmail.com
authors.forename: Wen-Jun
authors.initials: WJ
authors.lastname: Lan
authors.forename: Xiao-Xiang
authors.initials: XX
authors.lastname: Zheng
mesh_terms: D001775:Blood Circulation / Q000187:drug effects; D042783:Endothelial Cells / Q000187:drug effects; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects*; D005434:Flow Cytometry; D020441:Ginkgo biloba / Q000737:chemistry*; D006801:Humans; D010936:Plant Extracts / Q000494:pharmacology; D011794:Quercetin / Q000494:pharmacology*; D018180:Thrombomodulin / Q000378:metabolism*; D010959:Tissue Plasminogen Activator / Q000378:metabolism*; D014471:Umbilical Veins / Q000166:cytology
chemical_list: D010936:Plant Extracts; D018180:Thrombomodulin; D011794:Quercetin; D010959:Tissue Plasminogen Activator