Ex Vivo Antioxidant Capacities of Fruit and Vegetable Juices. Potential In Vivo Extrapolation.

BACKGROUND: In support of claims that their products have antioxidant properties, the food industry and dietary supplement manufacturers rely solely on the in vitro determination of the ORAC (oxygen radical antioxidant capacity) value, despite its acknowledged lack of any in vivo relevance. It thus appears necessary to use tests exploiting biological materials (blood, white blood cells) capable of producing physiological free radicals, in order to evaluate more adequately the antioxidant capacities of foods such as fruit and vegetable juices. MATERIALS: Two approaches to assessing the antioxidant capacities of 21 commercial fruit and vegetable juices were compared: the ORAC assay and the "PMA-whole blood assay," which uses whole blood stimulated by phorbol myristate acetate to produce the superoxide anion. We described in another paper the total polyphenol contents (TPCs) and individual phenolic compound contents of all the juices were investigated. RESULTS: Ranking of the juices from highest to lowest antioxidant capacity differed considerably according to the test used, so there was no correlation (r = 0.33, p = 0.13) between the two assays when considering all juices. Although the results of the ORAC assay correlated positively with TPC (r = 0.50, p = 0.02), a much stronger correlation (r = 0.70, p = 0.004) emerged between TPC and % superoxide anion inhibition. In the PMA-whole blood assay, peonidin-3-O-glucoside, epigallocatechin gallate, catechin, and quercetin present in juices were found to inhibit superoxide anion production at concentrations below 1 µM, with a strong positive correlation. CONCLUSIONS: Associated with the determination of total and individual phenolic compounds contained in fruit and vegetable juices, the PMA-whole blood assay appears better than the ORAC assay for evaluating juice antioxidant capacity.

Compared Phenolic Compound Contents of 22 Commercial Fruit and Vegetable Juices: Relationship to ex-vivo Vascular Reactivity and Potential in vivo Projection.

The real impact of polyphenol-rich vegetable and fruit juice intake on cardiovascular health remains a matter of controversy. In the present study, rat aorta segments immersed in an organ bath (OB) were used to explore whether the total polyphenol content and/or individual phenolic compound contents of 22 commercial vegetable (n = 3) and fruit juices [(citrus (n = 5), berries (n = 10), apple (n = 2), pineapple (n = 2)] might be associated with vascular tone. Red juices (particularly blackcurrant) and lemon juice caused the most marked vasorelaxation, its amplitude being endothelium dependent or not according to the volume ratio of juice to initial OB solution Vjuice/VOBS). At volume ratios 5% and 10%, both the juice and OB total polyphenol for all juices and total anthocyanin contents for berry juices significantly correlated with aorta vasorelaxation intensity. This was not the case for total or individual flavonols (except kaempferol) or for total or individual flavanols (except epigallocatechin gallate). If one relates our measured concentrations of individual phenolic compounds in OB to what is known about their physiological concentrations, and given our evidenced correlations between compound concentrations and vasorelaxation intensity, kaempferol, epigallocatechin gallate and peonidin-3-O-glucoside seem to emerge as the interesting phenolic compounds likely to be responsible for the potent vasorelaxation observed with fruit juices, and more particularly blackcurrant ones. Clinical investigation is required, however, to confirm our observations.

Platelet Acetyl-CoA Carboxylase Phosphorylation: A Risk Stratification Marker That Reveals Platelet-Lipid Interplay in Coronary Artery Disease Patients.

Adenosine monophosphate-activated protein kinase (AMPK) acetyl-CoA carboxylase (ACC) signaling is activated in platelets by atherogenic lipids, particularly by oxidized low-density lipoproteins, through a CD36-dependent pathway. More interestingly, increased platelet AMPK-induced ACC phosphorylation is associated with the severity of coronary artery calcification as well as acute coronary events in coronary artery disease patients. Therefore, AMPK-induced ACC phosphorylation is a potential marker for risk stratification in suspected coronary artery disease patients. The inhibition of ACC resulting from its phosphorylation impacts platelet lipid content by down-regulating triglycerides, which in turn may affect platelet function.

Abdominal Aortic Aneurysm (AAA): Is There a Role for the Prevention and Therapy Using Antioxidants?

BACKGROUND: Abdominal aortic aneurysm (AAA) is a degenerative disease that causes mortality in people aged > 65 years. Increased reactive oxygen species (ROS) and oxidative stress seem to play a pivotal role in AAA pathogenesis. Several sources of ROS have been identified in aortic tissues using experimental models: inflammation, increased activity of NAD(P)H or NOX, over-expression of inducible nitric oxide synthase (iNOS), uncoupled endothelial nitric oxide synthase (eNOS), platelets activation and iron release from hemoglobin. OBJECTIVES: Human studies confirmed that oxidative stress and endothelial dysfunction, an important source of ROS production, were well associated with AAA development. Reducing oxidative stress by antioxidants can therefore be a good strategy for limiting AAA development. The objective of the present study is to review literature data favoring or not such a hypothesis. There is currently no evidence showing that strategies using classical low molecular weight antioxidants (vitamins C and E, ß- carotene) as target for ROS is effective to reduce human AAA progression. However, recent epidemiological data have highlighted the positive role of a diet enriched in fruits which contain high amounts of antioxidant polyphenols. By their ability to restore endothelial function and also their capacity to stimulate enzymatic antioxidants through activation of the Keap1/Nrf2/ARE pathway, polyphenols can represent a promising treatment target for reducing human AAA progression. CONCLUSION: Clinical studies are therefore urgently necessary to confirm the potential beneficial effect of polyphenols in preventing or limiting AAA.

Therapeutic Applications of Prostaglandins and Thromboxane A2 Inhibitors in Abdominal Aortic Aneurysms.

BACKGROUND: Abdominal aortic aneurysm (AAA) is one of the leading causes of death in western countries. Surgery is still, at the present time, the sole treatment that has however a significant mortality and cost rate. Many pharmacological agents are under investigation aiming to reduce growth and prevent AAA rupture. These drugs target different pathological pathways and, notably, the excessive production of prostanoids by cyclooxygenases (COX). Intra-aneurysmal thrombus plays an adverse key role in the progression of AAA, platelets being a primary source of prostanoids as thromboxane A2. OBJECTIVE: In this review, we summarize studies targeting prostanoids production and down-stream pathways in cardiovascular diseases, and more specifically in AAA. RESULTS AND CONCLUSION: Various inhibitors of COX or antagonists of prostanoids receptors have been investigated in AAA animal models with conflicting results. In human AAA, only a few number of studies focused on anti-platelet therapy mostly using acetylsalicylic acid (aspirin, ASA), a COX1 inhibitor. Finally, we report preliminary promising results of a model of AAA in rats receiving a thromboxane A2 inhibitor, BM-573 that induced a reduction of aneurysmal growth.

Efficacy of the RemoweLL cardiotomy reservoir for fat and leucocyte removal from shed mediastinal blood: a randomized controlled trial.

INTRODUCTION: Re-transfusion of lipid particles and activated leucocytes with shed mediastinal blood (SMB) can aggravate cardiopulmonary bypass-associated inflammation and increase the embolic load. This study evaluated the fat and leucocyte removal capacity of the RemoweLL cardiotomy reservoir. METHODS: Forty-five patients undergoing elective on-pump cardiac surgery were randomly allocated to filtration of SMB using the RemoweLL or the Admiral cardiotomy reservoir. The primary outcome was a drop in leucocytes and lipid particles obtained with the two filters. The effect of the filters on other blood cells and inflammatory mediators, such as myeloperoxidase (MPO), was also assessed. RESULTS: The RemoweLL cardiotomy filter removed 16.5% of the leucocytes (p<0.001) while no significant removal of leucocytes was observed with the Admiral (p=0.48). The percentage reductions in lipid particles were similar in the two groups (26% vs 23%, p=0.2). Both filters similarly affected the level of MPO (p=0.71). CONCLUSION: The RemoweLL filter more effectively removed leucocytes from SMB than the Admiral. It offered no advantage in terms of lipid particle clearance.

Multimodality imaging assessment of the deleterious role of the intraluminal thrombus on the growth of abdominal aortic aneurysm in a rat model.

OBJECTIVES: To evaluate imaging changes occurring in a rat model of elastase-induced abdominal aortic aneurysm (AAA), with emphasis on the intraluminal thrombus (ILT) occurrence. METHODS: The post-induction growth of the AAA diameter was characterized using ultrasound in 22 rats. ILT was reported on 13 rats that underwent 14 magnetic resonance imaging (MRI) 2-18 days post-surgery, and on 10 rats that underwent 18 fluoro-deoxyglucose (FDG) positron emission tomography (PET)/microcomputed tomography examinations 2-27 days post-surgery. Logistic regressions were used to establish the evolution with time of AAA length, diameter, ILT thickness, volume, stratification, MRI and FDG PET signalling properties, and histological assessment of inflammatory infiltrates. RESULTS: All of the following significantly increased with time post-induction (p < 0.001): AAA length, AAA diameter, ILT maximal thickness, ILT volume, ILT iron content and related MRI signalling changes, quantitative uptake on FDG PET, and the magnitude of inflammatory infiltrates on histology. However, the aneurysm growth peak followed occurrence of ILT approximately 6 days after elastase infusion. CONCLUSION: Our model emphasizes that occurrence of ILT precedes AAA peak growth. Aneurysm growth is associated with increasing levels of iron, signalling properties changes in both MRI and FDG PET, relating to its biological activities. KEY POINTS: • ILT occurrence in AAA is associated with increasing FDG uptake and growth. • MRI signalling changes in ILT reflect activities such as haemorrhage and RBC trapping. • Monitoring ILT activities using MRI may require no exogenous contrast agent.

(Tissue PET) Vascular metabolic imaging and peripheral plasma biomarkers in the evolution of chronic aortic dissections.

AIMS: Despite adequate medical management, dissection of the descending aorta (type B) may develop complications, including aneurysmal progression and eventually rupture. Partial false lumen thrombosis has been identified as a marker of adverse evolution in chronic dissection. The aim of this study was to test the ability of complementary information, provided by (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography/computed tomography (PET/CT) and peripheral biomarkers, to add pathophysiological significance and a prognostic value to morphological data. METHODS AND RESULTS: We explored serial aortic (18)F-FDG uptake by PET/CT imaging and plasma biomarkers in a series of 23 patients with type B dissection to predict complications from initial data and to investigate potential associations with aneurysmal expansion during follow-up. Complications occurred in 17 patients. Acute initial characteristics associated with complications were male gender (P = 0.021), arterial hypertension (P = 0.040), aortic dissection diameter (P = 0.0086), partial thrombosis of the false channel (P = 0.0046), and enhanced focal (18)F-FDG uptake (P = 0.045). During follow-up (mean 16.7 ± 8.0 months), aneurysmal expansion was associated with false lumen morphology (P< 0.0001), quantitative (18)F-FDG uptake, (P = 0.0029), elevated plasma concentrations of biomarkers of platelets (P-selectin, P = 0.0009) and thrombin activation (TAT complexes, P = 0.0075), and fibrinolysis (PAP complexes, P < 0.0001; D-dimers, P = 0.0006). Plasma markers of coagulation and fibrinolysis were related to false channel morphology, suggesting that thrombus biological dynamics may drive progressive expansion of type B dissections. CONCLUSION: Enhanced FDG uptake may be considered as a complementary imaging marker associated with secondary complications in type B dissections. During follow-up, aneurysmal progression is related to PET/CT and biomarkers of thrombus renewal and lysis.

Family members of patients with abdominal aortic aneurysms are at increased risk for aneurysms: analysis of 618 probands and their families from the Liège AAA Family Study.

BACKGROUND: The objectives were to answer the following questions with the help of a well-characterized population in Liège, Belgium: 1) what percentage of patients with abdominal aortic aneurysm (AAA) have a positive family history for AAA? 2) what is the prevalence of AAAs among relatives of patients with AAA? and 3) do familial and sporadic AAA cases differ in clinical characteristics? METHODS: Patients with unrelated AAA diagnosed at the Cardiovascular Surgery Department, University Hospital of Liège, Belgium, between 1999 and 2012 were invited to the study. A detailed family history was obtained in interviews and recorded using Progeny software. We divided the 618 patients into 2 study groups: group I, 296 patients with AAA (268; 91% men) were followed up with computerized tomography combined with positron emission tomography; and group II, 322 patients with AAA (295; 92% men) whose families were invited to ultrasonographic screening. RESULTS: In the initial interview, 62 (10%) of the 618 patients with AAA reported a positive family history for AAA. Ultrasonographic screening identified 24 new AAAs among 186 relatives (≥50 years) of 144 families yielding a prevalence of 13%. The highest prevalence (25%) was found among brothers. By combining the number of AAAs found by ultrasonographic screening with those diagnosed previously the observed lifetime prevalence of AAA was estimated to be 32% in brothers. The familial AAA cases were more likely to have a ruptured AAA than the sporadic cases (8% vs. 2.4%; P < 0.0001). CONCLUSIONS: The findings confirm previously found high prevalence of AAA among brothers, support genetic contribution to AAA pathogenesis, and provide rationale for targeted screening of relatives of patients with AAA.

Effects of large-pore hemofiltration in a swine model of fulminant hepatic failure.

Among the different potential mechanisms that could lead to brain edema and intracranial hypertension in fulminant hepatic failure (FHF), the inflammatory hypothesis implies that systemic inflammation might be in part responsible for an increase in cerebral blood flow (CBF) and brain water content. In this study, the authors used a validated ischemic FHF swine model to evaluate the effects of 80 kDa large-pore membrane hemofiltration (LPHF) on intracranial pressure (ICP) and CBF, in relation with the clearance of proinflammatory cytokines and blood liver tests, as primary end points. Fifteen pigs were randomized into one of three groups: SHAM, FHF, and FHF + LPHF. All experiments lasted 6 h. In the FHF groups, liver failure was induced by liver ischemia. After 2 h, the FHF + LPHF group underwent 4 h of a zero-balance continuous veno-venous hemofiltration using a 0.7-m(2), large-pore (78 Å) membrane with a cutoff of 80 kDa. ICP, CBF, mean arterial pressure, central venous pressure, and heart rate were continuously monitored and recorded. Arterial aspartate aminotransferase, total bilirubin, creatinine, international normalized ratio, glucose, lactate and serum cytokines interleukin (IL)-6, IL-10, and tumor necrosis factor-α were measured at T0, T120, and T360. Over the 6 h following liver ischemia, the FHF group developed a significant increase in ICP. This ICP rise was not observed in the SHAM group and was attenuated in the FHF + LDHF group. However, the ICP levels were not different at T360 in the FHF + LDHF group compared to the FHF group. No significant effect of LPHF on liver tests or levels of proinflammatory cytokines could be demonstrated. In this model, 80 kDa LPHF was not efficient to control FHF intracranial hypertension and to decrease serum cytokine levels.

Lifestyle Behaviours and Plasma Vitamin C and ß-Carotene Levels from the ELAN Population (Liège, Belgium).

Several factors, including fruit and vegetables intakes, have been shown to significantly influence the plasma concentrations of the two antioxidants vitamin C and ß-carotene. Deficiency levels of 6 mg/L (34.2 µM) for vitamin C and of 0.22 mg/L (0.4 µM) for ß-carotene have been suggested below which cardiovascular risk might be increased. The present study performed on 897 presumably healthy subjects aged 40-60 years aimed to examine how modifiable lifestyle factors may be related to vitamin C and/or ß-carotene deficiency. Gender, smoking, lack of regular physical activity and of daily fruit consumption (≥2/day), and social status (in particular, unemployment) were found to be significant risk factors for vitamin C deficiency. For ß-carotene deficiency, the same factors were identified except social status; moreover, overweight and OC use in women were also found to have a deleterious effect. For non exposed subjects, the probability of developing vitamin C deficiency was 4% in men and 2.4% in women. This probability increased to 66.3% for men and to 44.3% for women (and even to 50.4% under OC use), when all risk factors were present. For ß-carotene deficiency, the corresponding probabilities were equal to 29.7% in men and 13.7% in women (no risk factor present), and to 86.1% for men and 69.9% (91.6% for OC use) for women (all factors present), respectively.