title: Effects of oleuropein and pinoresinol on microvascular damage induced by hypoperfusion and reperfusion in rat pial circulation.
abstract: OBJECTIVE
  The present study was aimed to assess the in vivo acute effects of oleuropein or/and pinoresinol, polyphenols widely diffused in natural sources, on rat pial microvascular responses during transient BCCAO and reperfusion.
  
  
  METHODS
  Rat pial microcirculation was visualized by fluorescence microscopy through a closed cranial window. Pial arterioles were classified into five orders of branching. Capillaries were assigned order 0, the smallest arterioles order 1 and the largest ones order 5.
  
  
  RESULTS
  Rats subjected to BCCAO and reperfusion showed: arteriolar diameter decrease, microvascular leakage, leukocyte adhesion in venules, and reduction in capillary perfusion. Pretreatment with oleuropein or pinoresinol, a higher dose before BCCAO determined dilation in all arteriolar orders RE. Microvascular leakage was reduced as well as leukocyte adhesion and ROS formation, while capillary perfusion was protected. Inhibition of endothelium nitric oxide synthase prior to oleuropein or pinoresinol reduced the effect of these polyphenols on pial arteriolar diameter and leakage. These substances, administered together, prevented microvascular damage to a larger extent.
  
  
  CONCLUSIONS
  Oleuropein and pinoresinol were both able to protect pial microcirculation from I-reperfusion injury, to increase nitric oxide release and to reduce oxidative stress preserving pial blood flow distribution.
authors.affiliation: Department of Clinical Medicine and Surgery, Federico II University Medical School, Naples, Italy.
authors.forename: Dominga
authors.initials: D
authors.lastname: Lapi
authors.forename: Martina
authors.initials: M
authors.lastname: Di Maro
authors.forename: Teresa
authors.initials: T
authors.lastname: Mastantuono
authors.forename: Laura
authors.initials: L
authors.lastname: Battiloro
authors.forename: Lina
authors.initials: L
authors.lastname: Sabatino
authors.forename: Espedita
authors.initials: E
authors.lastname: Muscariello
authors.forename: Antonio
authors.initials: A
authors.lastname: Colantuoni
mesh_terms: D000818:Animals; D001160:Arterioles / Q000473:pathology / Q000503:physiopathology; D001930:Brain Injuries / Q000188:drug therapy / Q000473:pathology / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D005663:Furans / Q000494:pharmacology*; D057888:Iridoid Glucosides; D039823:Iridoids / Q000494:pharmacology*; D017705:Lignans / Q000494:pharmacology*; D008297:Male; D008833:Microcirculation / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000188:drug therapy / Q000473:pathology / Q000503:physiopathology*; D014665:Vasodilator Agents / Q000494:pharmacology*
chemical_list: D005663:Furans; D057888:Iridoid Glucosides; D039823:Iridoids; D017705:Lignans; D014665:Vasodilator Agents; C002769:oleuropein; C103298:pinoresinol
keywords: bilateral common carotid artery occlusion; endothelial nitric oxide; oleuropein; pial microcirculation; pinoresinol; reperfusion; vasodilation