Cranberry juice has been long used to prevent infections because of its effect on the adhesion of the bacteria to the host surface. Proanthocyanidins (PACs) comprise of one of the major classes of phytochemicals found in cranberry, which have been extensively studied and found effective in combating adhesion of pathogenic bacteria. The role of other cranberry constituents in impacting bacterial adhesion haven't been studied very well. In this study, cranberry juice fractions were prepared, characterized and tested for their effect on the surface adhesion of the pathogenic clinical bacterial strain E. coli B78 and non-pathogenic control E. coli HB101. The preparations tested included crude cranberry juice extract (CCE); three fractions containing flavonoid classes including proanthocyanidins, anthocyanins and flavonols; selected sub-fractions, and commercially available flavonol glycoside, quercetin-3-O-galactoside. Atomic force microscopy (AFM) was used to quantify the adhesion forces between the bacterial surface and the AFM probe after the treatment with the cranberry fractions. Adhesion forces of the non-pathogenic, non fimbriated lab strain HB101 are small (average force 0.19 nN) and do not change with cranberry treatments, whereas the adhesion forces of the pathogenic, Dr adhesion E. coli strain B78 (average force of 0.42 nN) show a significant decrease when treated with cranberry juice extract or fractions (average force of 0.31 nN, 0.37 nN and 0.39 nN with CCE, Fraction 7 and Fraction 4 respectively). In particular, the fractions that contained flavonols in addition to PACs were more efficient at lowering the force of adhesion (average force of 0.31 nN-0.18 nN between different sub-fractions containing flavonols and PACs). The sub-fractions containing flavonol glycosides (from juice, fruit and commercial quercetin) all resulted in reduced adhesion of the pathogenic bacteria to the model probe. This strongly suggests the anti adhesive role of other classes of cranberry compounds in conjunction with already known PACs and may have implications for development of alternative anti bacterial treatments.

In recent years, obesity, metabolic syndrome and diabetes are becoming epidemic both in developed and developing countries. Recent experimental and clinical studies have raised interest in the potential health benefits of cranberry consumption in obesity and metabolic syndrome, which appear to be associated with the phytochemical composition of this fruit. Interestingly, cranberry administration has been reported to ameliorate dyslipidemia, hyperglycaemia and oxidative stress in individuals with the metabolic syndrome. This review focuses on the recent findings regarding beneficial effects of cranberry on obesity and metabolic syndrome, and discusses its potential mechanisms of action. The results of studies presented in this review have demonstrated that cranberry ameliorates insulin resistance and plasma lipid profile, decreases diet-induced weight gain and visceral obesity, and diminishes blood markers of oxidative stress. Thus, cranberry could be an effective and safe component of functional foods addressed for individuals with metabolic complications.

Oxidative stress and inflammation are involved in the development of obesity, type 2 diabetes and vascular complications. Systemic inflammation, as seen in obesity, is associated with high plasmatic levels of pro-inflammatory, pro-atherogenic and pro-thrombotic adipokines. Here we studied the effects of lyophilized cranberries (LCB) on the secretion and expression of PAI-1, IL-6, MCP-1 and leptin in mature 3T3-L1 adipocytes under baseline conditions and excessive inflammatory response elicitation by stimulation with H2O2. Our data demonstrated that LCB significantly reduced the expression and secretion of IL-6, MCP-1 and leptin, as well as suppressed the overexpression of PAI-1 induced by H2O2. Our findings suggested that LCB counteracted the stimulatory effect of H2O2 on secretion and expression of pro-inflammatory adipokines, implying a potential anti-inflammatory effect during the inflammatory process induced via oxidative stress in adipose tissue.

Cranberry has been used traditionally to prevent urinary tract infections (UTIs), primarily among generally healthy women prone to recurrent UTIs. Results from a number of published clinical studies have supported this benefit; however, meta-analyses on cranberry and UTI prevention have reported conflicting conclusions. This article explores the methodological differences that contributed to these disparate findings. Despite similar research questions, the meta-analyses varied in the studies that were included, as well as the data that were extracted. In the 2 most comprehensive systematic reviews, heterogeneity was handled differently, leading to an I2 of 65% in one and 43% in the other. Most notably, the populations influencing the conclusions varied. In one analysis, populations with pathological/physiological conditions contributed 75.6% of the total weight to the summary risk estimate (RR: 0.86; 95% CI: 0.71, 1.04); another weighted the evidence relatively equally across UTI populations (RR: 0.62; 95% CI: 0.49, 0.80); and a third included only women with recurrent UTIs (RR: 0.53; 95% CI: 0.33, 0.83). Because women with recurrent UTIs are the group to whom most recommendations regarding cranberry consumption is directed, inclusion of other groups in the efficacy assessment could influence clinical practice quality. Therefore, conclusions on cranberry and UTIs should consider differences in results across various populations studied when interpreting results from meta-analyses.

SCOPE: Cranberries are rich in potentially bioactive (poly)phenols. The aim of this work was to investigate whether cranberry juice intake can improve vascular function in healthy men in a dose- and time-dependent manner, and to understand which of the circulating (poly)phenol metabolites correlate with vascular effects. METHODS AND RESULTS: A double-blind randomized controlled crossover trial was conducted in 10 healthy males. Flow-mediated dilation (FMD), blood pressure, pulse wave velocity and augmentation index were investigated at baseline, 1, 2, 4, 6, and 8h post-consumption of cranberry juices containing 409, 787, 1238, 1534, and 1910 mg of total cranberry (poly)phenols (TP), and a control drink. Plasma (poly)phenol metabolites were analyzed by UPLC-Q-TOF MS using authentic standards. We observed dose-dependent increases in FMD at 1, 2, 4, 6, and 8h with a peak at 4h and maximal effects with juice containing 1238 mg TP. A total of 60 metabolites were quantified in plasma after cranberry consumption. Twelve (poly)phenol metabolites significantly correlated with the increases in FMD, including ferulic and caffeic acid sulfates, quercetin-3-O-s-D-glucuronide and a gamma-valerolactone sulfate. CONCLUSION: (Poly)phenols in cranberry juice can improve vascular function in healthy males and this is linked to the presence of specific newly identified plasma metabolites.

Proteus mirabilis is a major cause of catheter-associated urinary tract infection (CAUTI), emphasizing that novel strategies for targeting this bacterium are needed. Potential targets are P. mirabilis surface-associated swarming motility and the propensity of these bacteria to form biofilms that may lead to catheter blockage. We previously showed that the addition of cranberry powder (CP) to lysogeny broth (LB) medium resulted in impaired P. mirabilis swarming motility over short time periods (up to 16 h). Herein, we significantly expanded on those findings by exploring (i) the effects of cranberry derivatives on biofilm formation of P. mirabilis, (ii) whether swarming inhibition occurred transiently or over longer periods more relevant to real infections (~3 days), (iii) whether swarming was also blocked by commercially available cranberry juices, (iv) whether CP or cranberry juices exhibited effects under natural urine conditions, and (v) the effects of cranberry on medium pH, which is an indirect indicator of urease activity. At short time scales (24 h), CP and commercially available pure cranberry juice impaired swarming motility and repelled actively swarming bacteria in LB medium. Over longer time periods more representative of infections (~3 days), the capacity of the cranberry material to impair swarming diminished and bacteria would start to migrate across the surface, albeit by exhibiting a different motility phenotype to the regular "bull's-eye" swarming phenotype of P. mirabilis. This bacterium did not swarm on urine agar or LB agar supplemented with urea, suggesting that any potential application of anti-swarming compounds may be better suited to settings external to the urine environment. Anti-swarming effects were confounded by the ability of cranberry products to enhance biofilm formation in both LB and urine conditions. These findings provide key insights into the long-term strategy of targeting P. mirabilis CAUTIs.

BACKGROUND: We recently reported that a cranberry proanthocyanidin rich extract (C-PAC) induces autophagic cell death in apoptotic resistant esophageal adenocarcinoma (EAC) cells and necrosis in autophagy resistant cells. EAC is characterized by high morbidity and mortality rates supporting development of improved preventive interventions. OBJECTIVE: The current investigation sought to investigate the role of reactive oxygen species (ROS) in the context of C-PAC induced cell death. METHODS: Apanel of human esophageal cell lines of EAC or BE (Barrett's esophagus) origin were treated with C-PAC and assessed for ROS modulation using CellROXReg. Green reagent and the Amplex Red assay to specifically measure hydrogen peroxide levels. RESULTS: C-PAC significantly increased ROS levels in EAC cells, but significantly reduced ROS levels in CP-C BE cells. Increased hydrogen peroxide levels were also detected in C-PAC treated EAC cells and supernatant; however, hydrogen peroxide levels were significantly increased in medium alone, without cells, suggesting that C-PAC interferes or directly acts on the substrate. Hydrogen peroxide levels did not change in C-PAC treated CP-C BE cells. CONCLUSION: These experiments provide additional mechanistic insight regarding C-PAC induced cancer cell death through modulation of ROS. Additional research is warranted to identify specific ROS species associated with C-PAC exposure.

Cranberry phenolic compounds have been linked to many health benefits. A recent report suggested that cranberry bioactives inhibit adipogenesis in 3T3-L1 adipocytes. Thus, we investigated the effects and mechanisms of the cranberry product (CP) on lipid metabolism using the Caenorhabditis elegans (C. elegans) model. CP (0.016% and 0.08%) dose-dependently reduced overall fat accumulation in C. elegans (N2, wild type) by 43% and 74%, respectively, without affecting its pumping rates or locomotive activities. CP decreased fat accumulation in aak-2 (an ortholog of AMP-activated kinase alpha ) and tub-1 (an ortholog of TUBBY) mutants significantly, but only minimal effects were observed in sbp-1 (an ortholog of sterol response element-binding protein-1) and nhr-49 (an ortholog of peroxisome proliferator-activated receptor- alpha ) mutant strains. We further confirmed that CP downregulated sbp-1, cebp, and hosl-1 (an ortholog of hormone-sensitive lipase homolog) expression, while increasing the expression of nhr-49 in wild-type C. elegans. These results suggest that CP could effectively reduce fat accumulation in C. elegans dependent on sbp-1, cebp, and nhr-49, but not aak-2 and tub-1.

The 4-(dimethylamino)cinnamaldehyde (DMAC) assay is currently used to quantify proanthocyanidin (PAC) content in cranberry products. In a multi-operator/multi-day study design, a cranberry proanthocyanidin (c-PAC) standard was compared to procyanidin A2 (ProA2) dimer for accurate quantification of PAC in commercial cranberry juices, lab generated cranberry blends and cranberry powders. The c-PAC standard reflects the structural heterogeneity of cranberry PAC degree of polymerization, hydroxylation pattern and ratios of 'A-type' to 'B-type' interflavanyl bonds. Use of the c-PAC standard to quantify PAC content in cranberry samples resulted in values that were 3.6 times higher than those determined by ProA2. Overall, there was no effect (P>0.05) of operator or day on estimation of PAC concentration. The adoption of c-PAC standard should be considered as an improvement over the use of ProA2 for accurate quantification of cranberry PAC. Improved standardization of bioactive PAC components in functional cranberry foods will aid in establishment of dosage guidelines.

The protective effect of proanthocyanidin-containing polyphenol extracts from apples, avocados, cranberries, grapes, or proanthocyanidin microbial metabolites was evaluated in colonic epithelial cells exposed to p-cresol, a deleterious compound produced by the colonic microbiota from L-tyrosine. In HT29 Glc-/+ cells, p-cresol significantly increased LDH leakage and decreased ATP contents, whereas in Caco-2 cell monolayers, it significantly decreased the transepithelial electrical resistance and increased the paracellular transport of FITC-dextran. The alterations induced by p-cresol in HT29 Glc-/+ cells were prevented by the extracts from cranberries and avocados, whereas they became worse by extracts from apples and grapes. The proanthocyanidin bacterial metabolites decreased LDH leakage, ameliorating cell viability without improving intracellular ATP. All of the polyphenol extracts and proanthocyanidin bacterial metabolites prevented the p-cresol-induced alterations of barrier function. These results suggest that proanthocyanidin-containing polyphenol extracts and proanthocyanidin metabolites likely contribute to the protection of the colonic mucosa against the deleterious effects of p-cresol.