Effects of low habitual cocoa intake on blood pressure and bioactive nitric oxide: a randomized controlled trial.

Context: Regular intake of cocoa-containing foods is linked to lower cardiovascular mortality in observational studies. Short-term interventions of at most 2 weeks indicate that high doses of cocoa can improve endothelial function and reduce blood pressure (BP) due to the action of the cocoa polyphenols, but the clinical effect of low habitual cocoa intake on BP and the underlying BP-lowering mechanisms are unclear.

Objective: To determine effects of low doses of polyphenol-rich dark chocolate on BP.

Effect of cocoa and tea intake on blood pressure: a meta-analysis.

Background: Epidemiological evidence suggests blood pressure-lowering effects of cocoa and tea. We undertook a meta-analysis of randomized controlled trials to determine changes in systolic and diastolic blood pressure due to the intake of cocoa products or black and green tea.

Methods: MEDLINE, EMBASE, SCOPUS, Science Citation Index, and the Cochrane Controlled Trials Register were searched from 1966 until October 2006 for studies in parallel group or crossover design involving 10 or more adults in whom blood pressure was assessed before and after receiving cocoa products or black or green tea for at least 7 days.

Endothelial antioxidant actions of dihydropyridines and angiotensin converting enzyme inhibitors.

Dihydropyridines and angiotensin converting enzyme inhibitor effects on superoxide and nitric oxide (NO) were compared in high glucose (20 mM, 24 h)-treated human Ea.hy 926 endothelial cells. High glucose stimulated superoxide both extracellularly (lucigenin chemiluminescence, cytochrome c reduction) and intracellularly (dihydrorhodamine 123 fluorescence).

Antioxidant and nitric oxide-sparing actions of dihydropyridines and ACE inhibitors differ in human endothelial cells.

The effects of dihydropyridine Ca2+ channel blockers (DHP) and ACE inhibitors on superoxide formation and nitric oxide (NO) bioavailability were compared in human EA.Hy926 endothelial cells (EC). EC were stimulated 4 h with angiotensin II (Ang II, 10 nM) +/- study drugs.

Different antioxidative potencies of dihydropyridine calcium channel modulators in various models.

There is evidence that dihydropyridine calcium antagonists (DHP) play a beneficial role during the development of atherosclerosis. Since antioxidative properties of this substance class may be important, we investigated the antioxidative potency of the DHP prototype calcium channel antagonist nifedipine, the long acting calcium channel antagonist lacidipine, the DHP calcium channel agonist Bay K 8644 and the bulky DHP derivate Bay O 5572 (negligible effects on L-type calcium channels) in three different models. Additionally, we examined the potential correlation between lipophilic and antioxidative properties.