Polyphenols enhance platelet nitric oxide by inhibiting protein kinase C-dependent NADPH oxidase activation: effect on platelet recruitment.

Several studies demonstrated an inverse association between polyphenol intake and cardiovascular events. Platelet recruitment is an important phase of platelet activation at the site of vascular injury, but it has never been investigated whether polyphenols influence platelet recruitment. The aim of the study was to analyze in vitro whether two polyphenols, quercetin and catechin, were able to affect platelet recruitment.

Polyphenols synergistically inhibit oxidative stress in subjects given red and white wine.

Aim of this study was to analyse the relationship between the plasma levels of polyphenols and the antioxidant activity of red and white wine. Twenty healthy subjects (HS) were randomly allocated to drink 300 ml of red (n = 10) or white n = 10 wine for 15 days. Ten HS who refrained from any alcohol beverage for 15 days were used as control.

The association between hyperhomocysteinemia and ischemic stroke in patients with non-valvular atrial fibrillation.

Background And Objectives: Atrial fibrillation is complicated by a high rate of ischemic stroke. Previous studies have shown that an increased level of circulating total plasma homocysteine (tHcy) is an independent predictor of stroke, but it is unclear whether it is also predictive of stroke in patients with atrial fibrillation. The objective of this study was to evaluate whether increased tHcy is an independent predictor of cardio-embolic stroke in patients with non-valvular atrial fibrillation.

Tumor necrosis factor-alpha as trigger of platelet activation in patients with heart failure.

The clinical history of patients with heart failure (HF) is complicated by arterial thromboembolism. Platelet activation is reported in this population, but the underlying mechanism has not been clarified. Forty-two patients with HF scored according to New York Heart Association (NYHA) classification had higher levels of collagen-induced platelet aggregation, platelet tumor necrosis factor-alpha (TNF-alpha) receptor expression, and serum thromboxane B2 and higher circulating levels of TNF-alpha than 20 healthy subjects.

Vitamin C inhibits platelet expression of CD40 ligand.

Upon stimulation with agonists, platelets express CD40 ligand (CD40L), a transmembrane protein implicated in the initiation and progression of atherosclerotic disease. We have recently discovered that oxidative stress plays a major role in platelet CD40L expression. In this study, we sought to determine whether vitamin C, a known antioxidant, is able to influence platelet CD40L expression.

Antioxidants in peripheral arterial disease.

Peripheral arterial disease (PAD) is an important manifestation of systemic atherosclerosis that is characterized by obstruction of the arteries in the lower limbs. Experimental and epidemiological studies suggest a key role for oxidative stress in initiation and progression of the atherosclerotic process. The results of these studies provided a good basis for interventional trials with antioxidants, particularly with vitamin E, but the findings were conflicting.

gp91phox-dependent expression of platelet CD40 ligand.

Background: CD40 ligand (CD40L) expression on platelets is mediated by agonists, but the underlying mechanism is still unclear.

Methods And Results: CD40L expression was measured in platelets from healthy subjects both with and without the addition of antioxidants or a phospholipase A2 (PLA2) inhibitor and in platelets from 2 patients with an inherited deficiency of gp91phox. Immunoprecipitation analysis was also performed to determine whether normal platelets showed gp91phox expression.

Antioxidants in peripheral arterial disease.

Peripheral arterial disease (PAD) is an important manifestation of systemic atherosclerosis that is characterized by obstruction of the arteries in the lower limbs. Experimental and epidemiological studies suggested a key role for oxidative stress in initiation and progression of the atherosclerotic process. The results of these studies provided a good basis for interventional trials with antioxidants, particularly with vitamin E, but the findings were conflicting.