title: Panax notoginseng saponin is superior to aspirin in inhibiting platelet adhesion to injured endothelial cells through COX pathway in vitro.
abstract: OBJECTIVE
  This study was designed to investigate the effect of Panax notoginseng saponin (PNS) on platelet adhesion to injured endothelial cells (ECs) and platelet activation induced by injured ECs, and to explore its underlying mechanisms.
  
  
  METHODS
  Human umbilical vein endothelial cells (HUVECs) pretreated with aspirin (ASA,15μg/mL) or PNS (160μg/mL), or neither, were exposed to oxidized low-density lipoprotein (ox-LDL,80mg/L) for 16h. Platelets were then added and co-cultured with HUVECs for 5min. Platelet adhesion to ECs, platelet CD62p expression, and HUVEC apoptosis were assessed by fluorescence activated cell sorting (FACS)·Supernatant concentration of 6-keto-PGF1α and thromboxane 2 (TXB2) were measured by radioimmunoassay. Cyclooxygenase-1 (COX-1) and COX-2 protein expression were measured by western blotting.
  
  
  RESULTS
  The inhibitory effect of PNS on platelet activation was similar to ASA, but the inhibitory effect of PNS on platelet adhesion to ECs was superior to ASA. PNS modulated COX-2 expression, and increased 6-keto-PGF1α concentration in HUVECs, while down-regulated COX-1 expression and decreased supernatant TXB2 concentration in platelets. Co-culturing of injured HUVECs with platelets increased HUVEC apoptosis induced by ox-LDL compared with HUVECs cultured without platelets; ASA increased HUVEC apoptosis induced by ox-LDL when cultured without platelets, while decreased the apoptosis when co-cultured with platelets.
  
  
  CONCLUSIONS
  EC protection by ASA is closely associated with its inhibitory effect on platelet activation. PNS is superior to ASA in protecting ECs and in inhibiting platelet adhesion to injured ECs, and the regulation of COX pathway in both ECs and platelets might be the underlying mechanisms of PNS.
authors.affiliation: Center for Cardiovascular Disease, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing 100091, China.
authors.forename: Ming-Ming
authors.initials: MM
authors.lastname: Wang
authors.affiliation: Center for Cardiovascular Disease, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing 100091, China.
authors.forename: Mei
authors.initials: M
authors.lastname: Xue
authors.affiliation: Center for Cardiovascular Disease, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing 100091, China.
authors.forename: Yong-Gang
authors.initials: YG
authors.lastname: Xu
authors.affiliation: Center for Cardiovascular Disease, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing 100091, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Miao
authors.affiliation: Beijing University of Chinese Medicine, Beijing 100029, China.
authors.forename: Na
authors.initials: N
authors.lastname: Kou
authors.affiliation: Center for Cardiovascular Disease, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing 100091, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Yang
authors.affiliation: Beijing University of Chinese Medicine, Beijing 100029, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Center for Cardiovascular Disease, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing 100091, China. Electronic address: dz_shi@163.com.
authors.forename: Da-Zhuo
authors.initials: DZ
authors.lastname: Shi
mesh_terms: D001241:Aspirin / Q000494:pharmacology*; D001792:Blood Platelets / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D008077:Lipoproteins, LDL / Q000378:metabolism; D053723:Panax notoginseng / Q000737:chemistry; D015539:Platelet Activation / Q000187:drug effects; D010973:Platelet Adhesiveness / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism*; D012503:Saponins / Q000737:chemistry / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D008077:Lipoproteins, LDL; D010975:Platelet Aggregation Inhibitors; D012503:Saponins; C099252:oxidized low density lipoprotein; D011451:Prostaglandin-Endoperoxide Synthases; D001241:Aspirin
keywords: Aspirin; Endothelial cell; Panax notoginseng saponin; Platelet; Thrombogenesis