title: Relaxant and antioxidant capacity of the red wine polyphenols, resveratrol and quercetin, on isolated mice corpora cavernosa.
abstract: BACKGROUND
  The red wine polyphenols resveratrol and quercetin are known for their vasorelaxant and antioxidant capacity, which is assumed to rely on the activation of the nitric oxide (NO)/soluble guanylyl cyclase (sGC) pathway. Vasodilators as well as antioxidants can regulate penile erection and be beneficial for the treatment of erectile dysfunction (ED).
  
  
  OBJECTIVE
  The goal of this study was to evaluate the NO/sGC dependency of the relaxant effect of resveratrol and quercetin on mice aorta and corpora cavernosa (CC), as well as to explore their influence on oxidative stress-induced ED.
  
  
  METHODS
  Isolated mice aorta and CC were mounted for isometric tension recordings into organ baths. Cumulative concentration-response curves were constructed for resveratrol and quercetin in the absence/presence of inhibitors of the NO/sGC pathway. In addition, in CC the effect of resveratrol and quercetin was studied on NO-mediated relaxations using acetylcholine (Ach), sodium nitroprusside (SNP), and electrical field stimulation (EFS). In certain experiments, corporal tissues were exposed to oxidative stress using palmitic acid (PA, 0.5 mM).
  
  
  METHODS
  Corporal responses to resveratrol and quercetin were measured in the presence/absence of inhibitors of different molecular pathways. The effect of resveratrol and quercetin incubation on Ach-, SNP-, or EFS-mediated responses was explored in the presence/absence of PA.
  
  
  RESULTS
  While both polyphenols are potent vasodilators of mice aorta, only resveratrol relaxes mice CC. The relaxation response to resveratrol on aorta was diminished in sGCα1 (-/-) mice, but not on CC. The polyphenols did not influence Ach-, SNP-, or EFS-mediated relaxations as such. Resveratrol, but not quercetin, was able to significantly reverse PA-induced decrease of EFS relaxations.
  
  
  CONCLUSIONS
  The red wine compound resveratrol, but not quercetin, relaxes isolated mice CC concentration-dependently through mechanisms independent of the NO/sGC pathway. Resveratrol is a more potent antioxidant than quercetin, being able to restore decreased neuronal NO responses in mice CC.
authors.affiliation: Department of Pharmacology, Ghent University, Ghent, Belgium.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Boydens
authors.forename: Bart
authors.initials: B
authors.lastname: Pauwels
authors.forename: Kelly
authors.initials: K
authors.lastname: Decaluwé
authors.forename: Peter
authors.initials: P
authors.lastname: Brouckaert
authors.forename: Johan
authors.initials: J
authors.lastname: Van de Voorde
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D006162:Guanylate Cyclase / Q000378:metabolism; D008297:Male; D051379:Mice; D009569:Nitric Oxide / Q000378:metabolism; D009599:Nitroprusside / Q000494:pharmacology; D018384:Oxidative Stress / Q000187:drug effects; D010410:Penile Erection / Q000187:drug effects; D010413:Penis / Q000378:metabolism; D059808:Polyphenols / Q000494:pharmacology*; D011794:Quercetin / Q000494:pharmacology*; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D000077185:Resveratrol; D000071756:Soluble Guanylyl Cyclase; D013267:Stilbenes / Q000494:pharmacology*; D014665:Vasodilator Agents / Q000494:pharmacology*; D014920:Wine
chemical_list: D000975:Antioxidants; D059808:Polyphenols; D018160:Receptors, Cytoplasmic and Nuclear; D013267:Stilbenes; D014665:Vasodilator Agents; D009599:Nitroprusside; D009569:Nitric Oxide; D011794:Quercetin; D006162:Guanylate Cyclase; D000071756:Soluble Guanylyl Cyclase; D000109:Acetylcholine; D000077185:Resveratrol
keywords: Antioxidant; Corpora Cavernosa; Erectile Function; Quercetin; Resveratrol