title: Blood pressure-lowering effect of dietary (-)-epicatechin administration in L-NAME-treated rats is associated with restored nitric oxide levels.
abstract: Epidemiological and intervention studies have shown that the intake of certain chocolates or cocoa products decreases blood pressure (BP) in humans. (-)-Epicatechin is the most abundant flavanol present in cocoa seeds and its derived foods. This work investigates the effects of dietary (-)-epicatechin on BP in rats that received N(ω)-nitro-l-arginine methyl ester (L-NAME) for 4 days. (-)-Epicatechin administration prevented the 42mm Hg increase in BP associated with the inhibition of NO production in a dose-dependent manner (0.2-4.0g/kg diet). This BP effect was associated with a reduction in L-NAME-mediated increase in the indexes of oxidative stress (plasma TBARS and GSSG/GSH(2) ratio) and with a restoration of the NO concentration. At the vascular level, none of the treatments modified NOS expression, but (-)-epicatechin administration avoided the L-NAME-mediated decrease in eNOS activity and increase in both superoxide anion production and NOX subunit p47(phox) expression. In summary, (-)-epicatechin was able to prevent the increase in BP and in oxidative stress and restored NO bioavailability. The fact that (-)-epicatechin is present in several plants usually consumed by humans gives the possibility of developing diets rich in those plants or pharmacological strategies using that flavonoid to diminish BP in hypertensive subjects.
authors.affiliation: Physical Chemistry-IBIMOL, School of Pharmacy and Biochemistry, University of Buenos Aires-CONICET, Buenos Aires, Argentina.
authors.forename: Maria C
authors.initials: MC
authors.lastname: Litterio
authors.forename: Grayson
authors.initials: G
authors.lastname: Jaggers
authors.forename: Gulcin
authors.initials: G
authors.lastname: Sagdicoglu Celep
authors.forename: Ana M
authors.initials: AM
authors.lastname: Adamo
authors.forename: Maria A
authors.initials: MA
authors.lastname: Costa
authors.forename: Patricia I
authors.initials: PI
authors.lastname: Oteiza
authors.forename: Cesar G
authors.initials: CG
authors.lastname: Fraga
authors.forename: Monica
authors.initials: M
authors.lastname: Galleano
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000187:drug effects* / Q000502:physiology; D002392:Catechin / Q000494:pharmacology*; D019587:Dietary Supplements; D005978:Glutathione / Q000097:blood; D019803:Glutathione Disulfide / Q000097:blood; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology*; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000096:biosynthesis; D018384:Oxidative Stress / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D014664:Vasodilation / Q000187:drug effects
chemical_list: D009569:Nitric Oxide; D002392:Catechin; D019001:Nitric Oxide Synthase; D005978:Glutathione; D019803:Glutathione Disulfide; D019331:NG-Nitroarginine Methyl Ester