title: Does pycnogenol intensify the efficacy of acetylsalicylic acid in the inhibition of platelet function? In vitro experience.
abstract: BACKGROUND
  Some compounds of herbal origin, such as Pycnogenol (PYC), have been considered as an aid in antiplatelet therapy. Pycnogenol, a French maritime pine bark extract, is a complex mixture of polyphenols that has the ability to reduce human smoking-induced platelet aggregation. The aim of this study was to evaluate the in vitro ability of PYC to improve the efficacy of acetylsalicylic acid (ASA) in the inhibition of platelet function.
  
  
  METHODS
  Whole blood, anticoagulated with hirudin, was drawn from 38 volunteers (40.4+/-13.8 years old) and incubated with PYC (10, 50, 100 microg/ml) or/and ASA (25, 100 micromol/l) for 20 min at RT.PYC was dissolved in water (water-PYC group, n=20) or ethanol (ethanol-PYC group, n=18). To investigate platelet functions, PFA-100 closure-time determination, whole-blood electrical aggregation (WBEA), and PRP aggregation were employed. Collagen (1 microg/ml) and ADP (5 micromol/l) were used as platelet agonists.
  
  
  RESULTS
  A compounding effect of ASA and PYC to inhibit platelet function recorded in collagen-induced aggregation in PRP was observed, but only when ethanol-dissolved PYC was used. The inhibitory effect of PYC (alone) was most profound in platelets activated with ADP. At all concentrations, PYC significantly inhibited platelet aggregation only in the ethanol-PYC group.
  
  
  CONCLUSIONS
  It was found that under in vitro conditions, ethanol-dissolved PYC deepened the efficacy of ASA to inhibit platelet function. This study confirmed the direct and compounding (with ASA) inhibitory effect of PYC on platelets. These observations encourage the concept that the combined use of ASA and PYC may be beneficial in patients with impaired response to ASA therapy.
authors.affiliation: Department of Hemostasis and Hemostatic Disorders, Medical University Hospital No. 2, Medical University of Łódź, Łódź, Poland.
authors.forename: Jacek
authors.initials: J
authors.lastname: Golański
authors.forename: Jana
authors.initials: J
authors.lastname: Muchova
authors.forename: Ryszard
authors.initials: R
authors.lastname: Golański
authors.forename: Zdenka
authors.initials: Z
authors.lastname: Durackova
authors.forename: Leszek
authors.initials: L
authors.lastname: Markuszewski
authors.forename: Cezary
authors.initials: C
authors.lastname: Watała
mesh_terms: D000328:Adult; D001241:Aspirin / Q000494:pharmacology*; D001792:Blood Platelets / Q000187:drug effects / Q000502:physiology; D004357:Drug Synergism; D005419:Flavonoids / Q000494:pharmacology*; D006801:Humans; D010936:Plant Extracts; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*
chemical_list: D005419:Flavonoids; D010936:Plant Extracts; D010975:Platelet Aggregation Inhibitors; C024070:pycnogenols; D001241:Aspirin