BACKGROUND: Cranberry juice contains polyphenolic compounds that could improve endothelial function and reduce cardiovascular disease risk.
OBJECTIVE: The objective was to examine the effects of cranberry juice on vascular function in subjects with coronary artery disease.
DESIGN: We completed an acute pilot study with no placebo (n = 15) and a chronic placebo-controlled crossover study (n = 44) that examined the effects of cranberry juice on vascular function in subjects with coronary artery disease.
RESULTS: In the chronic crossover study, subjects with coronary heart disease consumed a research preparation of double-strength cranberry juice (54% juice, 835 mg total polyphenols, and 94 mg anthocyanins) or a matched placebo beverage (480 mL/d) for 4 wk each with a 2-wk rest period between beverages. Beverage order was randomly assigned, and participants refrained from consuming other flavonoid-containing beverages during the study. Vascular function was measured before and after each beverage, with follow-up testing >=12 h after consumption of the last beverage. Mean (+/-SD) carotid-femoral pulse wave velocity, a measure of central aortic stiffness, decreased after cranberry juice (8.3 +/- 2.3 to 7.8 +/- 2.2 m/s) in contrast with an increase after placebo (8.0 +/- 2.0 to 8.4 +/- 2.8 m/s) (P = 0.003). Brachial artery flow-mediated dilation, digital pulse amplitude tonometry, blood pressure, and carotid-radial pulse wave velocity did not change. In the uncontrolled pilot study, we observed improved brachial artery flow-mediated dilation (7.7 +/- 2.9% to 8.7 +/- 3.1%, P = 0.01) and digital pulse amplitude tonometry ratio (0.10 +/- 0.12 to 0.23 +/- 0.16, P = 0.001) 4 h after consumption of a single 480-mL portion of cranberry juice.
CONCLUSIONS: Chronic cranberry juice consumption reduced carotid femoral pulse wave velocity-a clinically relevant measure of arterial stiffness. The uncontrolled pilot study suggested an acute benefit; however, no chronic effect on measures of endothelial vasodilator function was found. This trial was registered at clinicaltrials.gov as NCT00553904.

This study investigated the effects of freeze-dried cranberry powder on anti-inflammation and lipid profiles of lipopolysaccharide (LPS)-treated rats fed an atherogenic diet for 6 weeks. Forty Sprague-Dawley male rats (6-weeks-old) were equally divided into the following five groups: 1) normal diet group + saline (NC); 2) atherogenic diet + saline (HFC); 3) atherogenic diet + LPS (HL); 4) atherogenic diet with 5% cranberry power + LPS (C5); 5) atherogenic diet with 10% cranberry power + LPS (C10). LPS (0.5 mg/kg) was injected into the abdominal cavities of rats 18 hours prior to sacrifice. At the end of the experimental period, we measured serum lipid profiles as well as levels of serum C-reactive protein (CRP), nitric oxide (NO), and pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, and IL-10 as an anti-inflammatory cytokine. The mean serum high density lipoprotein (HDL)-cholesterol level in C5 rats was significantly higher than that in NC and HL rats (P

Numerous studies have indicated that several polyphenol-rich sources such as red wine and green tea are potent inducers of endothelium-dependent relaxations in isolated arteries. As various fruits and berries are known to contain high levels of polyphenols, the aim of the present study was to assess the ability of selected pure fruit juices and purees as well as blends to cause endothelium-dependent relaxations in isolated arteries. Vascular reactivity was assessed using porcine coronary artery rings, and fruit juices, purees and blends were characterized for their content in vitamin C, total phenolic, sugar and antioxidant activity. Fruit juices and purees caused variable concentration-dependent relaxations, with blackcurrant, aronia, cranberry, blueberry, lingonberry, and grape being the most effective fruits. Several blends of red fruits caused endothelium-dependent relaxations. Relaxations to blend D involved both a NO- and an EDHF-mediated components. The present findings indicate that some berries and blends of red fruit juices are potent inducers of endothelium-dependent relaxations in the porcine coronary artery. This effect involves both endothelium-derived NO and EDHF, and appears to be dependent on their polyphenolic composition rather than on the polyphenolic content.

Obesity is a major and independent risk factor for cardiovascular disease and it is strongly associated with the development of dyslipidemia, insulin resistance and type 2 diabetes. Flavonoids, a diverse group of polyphenol compounds of plant origin widely distributed in human diet, have been reported to have numerous health benefits, although the mechanisms underlying these effects have remained obscure. We analyzed the effects of chronic dietary supplementation with flavonoids extracted from cranberry (FLS) in normal and obese C57/BL6 mice compared to mice maintained on the same diets lacking FLS. Obese mice supplemented with flavonoids showed an amelioration of insulin resistance and plasma lipid profile, and a reduction of visceral fat mass. We provide evidence that the adiponectin-AMPK pathway is the main mediator of the improvement of these metabolic disorders. In contrast, the reduced plasma atherogenic cholesterol observed in normal mice under FLS seems to be due to a downregulation of the hepatic cholesterol synthesis pathway. Overall, we demonstrate for the first time that the molecular mechanisms underlying the beneficial effects of flavonoids are determined by the metabolic state.

A cellular antioxidant activity (CAA) assay for quantifying the antioxidant activity of phytochemicals, food extracts, and dietary supplements has been developed. Dichlorofluorescin is a probe that is trapped within cells and is easily oxidized to fluorescent dichlorofluorescein (DCF). The method measures the ability of compounds to prevent the formation of DCF by 2,2′-azobis(2-amidinopropane)
dihydrochloride (ABAP)-generated peroxyl radicals in human hepatocarcinoma HepG2 cells. The decrease in cellular fluorescence when compared to the control cells indicates the antioxidant capacity of the compounds. The antioxidant activities of selected phytochemicals and fruit extracts were evaluated using the CAA assay, and the results were expressed in micromoles of quercetin equivalents per 100 μmol of phytochemical or micromoles of quercetin equivalents per 100 g of fresh fruit. Quercetin had the highest CAA value, followed by kaempferol, epigallocatechin gallate (EGCG), myricetin, and luteolin among the pure compounds tested. Among the selected fruits tested, blueberry had the highest CAA value, followed by cranberry > apple ) red grape > green grape. The CAA
assay is a more biologically relevant method than the popular chemistry antioxidant activity assays because it accounts for some aspects of uptake, metabolism, and location of antioxidant compounds within cells.

Chitosan binds to negatively charged soy lecithin liposomes by an electrostatic interaction driven by its positively charged amino group. This interaction allows stable covered vesicles (chitosomes) to be developed as a suitable targeted carrier and controlled release system. This study investigated the effect of chitosomes on the activation of cranberry proanthocyanidins (PAC) in Raw 264.7 macrophages. Chitosomes were characterized according to size, zeta potential, PAC-loading, and release properties. Results showed an increase in the net positive charge and size of the liposomes as the concentration of chitosan was increased, suggesting an effective covering of the vesicles by means of electrostatic interactions, as shown by transmission electron microscopy and fluorescence microscopy. About 85% of the PAC that was loaded remained in the chitosomes after release studies for 4 hours in phosphate-buffered saline. Cyclo-oxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) are associated with inflammation. Activated RAW 264.7 macrophages increase the expression of COX-2 and iNOS in response to bacterial infection and inflammation; we, therefore, tested the ability of the PAC-loaded chitosomes to attenuate COX-2 and iNOS expression in LPS (lipopolysaccharide)-stimulated macrophages. Increasing the amount of PAC loaded into the chitosomes caused a dose-dependent attenuation of iNOS and COX-2 expression in LPS-stimulated macrophages. A 2% v/v PAC-loaded chitosomes formulation almost completely attenuated the LPS-induced expression of iNOS and COX-2. PAC-loaded chitosomes were more active than PAC alone, suggesting that the macrophage response to LPS occurs after endocytosis of the PAC-loaded chitosomes.

Flavonoids can bind the divalent cations frequently used to evaluate LDL antioxidant capacity in vitro. Flavonoids in cranberry juice (CBJ) may serve as antioxidants and promote cardiovascular health. This in vitro study characterizes CBJ effects on metal and non-metal based oxidation of human LDL. For cupric ion-initiated oxidation of LDL, thiobarbituric acid reactive substances (TBARS) formation and relative electrophoretic mobility (REM) were significantly inhibited by CBJ at a dilution of 1:10,000. Diene formation during LDL oxidation was evaluated by continuous measurement of absorbance at 234 nm. The time required for cupric ion-initiated LDL oxidations to reach maximum reaction velocity was significantly delayed by 1:10,000 dilutions of CBJ. Non-metal initiated LDL oxidation by 2,2'-azobis-amidinopropane was significantly inhibited by CBJ at dilutions of 1:10,000 and 1:5,000 for REM and TBARS tests, respectively. Protection of LDL from both metal and non-metal based oxidative injury confirms that the effects of CBJ are not due to flavonoid chelation of oxidants but due to a true and potent antioxidant capacity.

Abstract: Antioxidant activity of six fractions of cranberry phenolic compounds was determined by
inhibition of Cu2+-induced low-density lipoprotein (LDL) oxidation. The phenolic composition of each fraction was determined by high-performance liquid chromatography. The phenolic fractions were mixed with aliquots of modified human serum prior to LDL isolation. The serum was modified to remove very-low-density lipoprotein and chylomicrons that may bind phenolic compounds. Only fractions 5 and 6 that contained proanthocyanidins (PAs) significantly increased the lag time of LDL oxidation, and the lag time for fraction 6 was significantly higher than for fraction 5. The mass distribution of PAs in these fractions was obtained by matrix-assisted laser desorption/ionisation time- of-flight mass spectrometry, a technique that allows rapid characterisation of the molecular weight distribution in mixtures of oligomeric compounds. Fraction 5 contained trimers through heptamers, whereas fraction 6 contained pentamers through nonamers. In addition, fraction 6 contained PA oligomers with more doubly linked, A-type interflavan bonds. Results indicate that PAs specifically associate with LDL in modified serum and increase the lag time of Cu2+-induced oxidation. Differences between fractions 5 and 6 in PA structure and effects on LDL oxidation suggest that the degree of polymerisation and the nature of the interflavan bond influence antioxidant properties

Abstract:Proanthocyanidin-rich extracts were prepared by fractionation of the fruit of theNorthAmerican cranberry (Vaccinium macrocarpon). In vitro growth inhibition assays in eight tumor cell lines showed that selected fractions inhibited the growth of H460 lung tumors, HT-29 colon and K562 leukemia cells at GI50 values ranging from 20 to 80 μgml−1. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) of one of these fractions found it to be composed of polyflavan-3-ols, which are primarily tetramers through heptamers of epicatechin containing one or two A-type linkages. Whole cranberry extract and the proanthocyanidin fractions were screened for effect on the expression of matrix metalloproteinases in DU 145 prostate carcinoma cells. The expression of MMP-2 and MMP-9 was inhibited in response to whole cranberry extract and to a lesser degree by the proanthocyanidin fractions

Although antioxidant systems help control the level of reactive oxygen species they may be overwhelmed during periods of oxidative stress. Evidence suggests that oxidative stress components as well as inflammatory mediators may be involved in the pathogenesis of vascular disorders, where localized markers of oxidative damage have been found. In this regard we investigated the putative antioxidant and anti-inflammatory effects of blueberry and cranberry anthocyanins and hydroxycinnamic acids against H2O2 and TNF induced damage to human microvascular endothelial cells. Polyphenols from both berries were able to localize into endothelial cells subsequently reducing
endothelial cells vulnerability to increased oxidative stress at both the membrane and cytosol level. Furthermore, berry polyphenols also reduced TNF induced up-regulation of various inflammatory mediators (IL-8, MCP-1 and ICAM-1) involved in the recruitment of leukocytes to sites of damage or inflammation along the endothelium. In conclusion, polyphenols isolated from both blueberry and cranberry were able to afford protection to endothelial cells against stressor induced up-regulation of oxidative and inflammatory insults. This may have beneficial actions against the initiation and development of vascular diseases and be a contributing factor in the reduction of age-related
deficits in neurological impairments previously reported by us