title: Olive oil polyphenol oleuropein inhibits smooth muscle cell proliferation.
abstract: OBJECTIVE
  The Mediterranean diet, with a high content of olive oil, is associated with a reduced risk of coronary artery disease. The aim of this study was to determine the effect of oleuropein, one of the polyphenols in olive oil, on vascular smooth muscle cell (SMC) proliferation in vitro.
  
  
  METHODS
  This was an experimental study.
  
  
  METHODS
  Bovine vascular SMCs were cultured in the presence of 100 μM of oleuropein. On days 1, 3 and 5, cell number was counted. Cell cycle analysis was performed by flow cytometry. Cell cycle regulators were assessed by immunoblotting.
  
  
  RESULTS
  Cell proliferation in the presence of oleuropein was significantly inhibited by 92%. Cell cycle analysis revealed that oleuropein treatment blocked cells in the G1-S phase compared with the non-treated group. Among G1 phase regulators, retinoblastoma protein, cyclinD, p21 and p27 were not affected by oleuropein, but extracellular signal-regulated kinase 1/2 (ERK1/2) activation was inhibited. Growth of SMC treated with 100 μM of the mitogen-activated protein (MAP) kinase/ERK kinase 1 (MEK1) inhibitor PD98059 was also significantly inhibited by 70%.
  
  
  CONCLUSIONS
  Oleuropein inhibited SMC proliferation through a cell cycle block between the G1 and the S phases, which may be regulated by ERK1/2. These results suggest a mechanism by which olive oil consumption may have beneficial effects on cardiovascular mortality by inhibiting SMC proliferation.
authors.affiliation: Department of Surgery, Section of Vascular Surgery, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520-8062, United States.
authors.forename: R
authors.initials: R
authors.lastname: Abe
authors.forename: J
authors.initials: J
authors.lastname: Beckett
authors.forename: R
authors.initials: R
authors.lastname: Abe
authors.forename: A
authors.initials: A
authors.lastname: Nixon
authors.forename: A
authors.initials: A
authors.lastname: Rochier
authors.forename: N
authors.initials: N
authors.lastname: Yamashita
authors.forename: B
authors.initials: B
authors.lastname: Sumpio
mesh_terms: D000818:Animals; D002417:Cattle; D018929:Cell Culture Techniques; D002453:Cell Cycle / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects*; D057888:Iridoid Glucosides; D039823:Iridoids; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D000069463:Olive Oil; D010938:Plant Oils / Q000494:pharmacology*; D011714:Pyrans / Q000494:pharmacology*; D013997:Time Factors; D014665:Vasodilator Agents / Q000494:pharmacology*
chemical_list: D057888:Iridoid Glucosides; D039823:Iridoids; D000069463:Olive Oil; D010938:Plant Oils; D011714:Pyrans; D014665:Vasodilator Agents; C002769:oleuropein