Chitosan interacts with proanthocyanidins through hydrogen-bonding, which allows encapsulation and development of stable nanoparticles via ionotropic gelation. Cranberry proanthocyanidins (PAC) are associated with the prevention of urinary tract infections and PAC inhibit invasion of gut epithelial cells by extra-intestinal pathogenic Escherichia coli (ExPEC). We determined the effect of cranberry proanthocyanidin-chitosan hybrid nanoparticles (PAC-CHTNp) on the ExPEC invasion of gut epithelial cells in vitro. PAC-CHTNp were characterized according to size, morphology, and bioactivity. Results showed a decrease in the size of the nanoparticles as the concentration of PAC was increased, indicating that PAC increases cross-linking by hydrogen-bonding on the surface of the chitosan nanoparticles. Nanoparticles were produced with diameters ranging from 367.3nm to 293.2nm. Additionally, PAC-CHTNp significantly inhibited the ability of ExPEC to invade the enterocytes by ~80% at 66mugGAE/mL and by ~92% at 100mugGAE/mL. Results also indicate that chitosan nanoparticles alone were not significantly different from controls in preventing ExPEC invasion of enterocytes (data not shown) and also there were not significant differences between PAC alone and PAC-CHTNp, suggesting that the new PAC-CHTNp could lead to an increase in the stability of encapsulated PAC, maintain the molecular adhesion of PAC to ExPEC.

Candida albicans is one of the most common causes of hospital-acquired urinary tract infections (UTIs). However, azoles are poorly active against biofilms, echinocandins do not achieve clinically useful urinary concentrations, and amphotericin B exhibits severe toxicities. Thus, novel strategies are needed to prevent Candida UTIs, which are often associated with urinary catheter biofilms. We previously demonstrated that cranberry-derived proanthocyanidins (PACs) prevent C. albicans biofilm formation in an in vitro urinary model. To elucidate functional pathways unique to urinary biofilm development and PAC inhibition, we investigated the transcriptome of C. albicans in artificial urine (AU), with and without PACs. C. albicans biofilm and planktonic cells were cultivated with or without PACs. Genome-wide expression analysis was performed by RNA sequencing. Differentially expressed genes were determined using DESeq2 software; pathway analysis was performed using Cytoscape. Approximately 2,341 of 6,444 total genes were significantly expressed in biofilm relative to planktonic cells. Functional pathway analysis revealed that genes involved in filamentation, adhesion, drug response and transport were up-regulated in urinary biofilms. Genes involved in carbon and nitrogen metabolism and nutrient response were down-regulated. In PAC-treated urinary biofilms compared to untreated control biofilms, 557 of 6,444 genes had significant changes in gene expression. Genes downregulated in PAC-treated biofilms were implicated in iron starvation and adhesion pathways. Although urinary biofilms share key features with biofilms formed in other environments, many genes are uniquely expressed in urinary biofilms. Cranberry-derived PACs interfere with the expression of iron acquisition and adhesion genes within urinary biofilms.

Uropathogenic Escherichia coli (UPEC) is the main infectious agent of urinary tract infections (UTI) in humans, dogs and cats. Dietary consumption of cranberries is thought to be associated with prevention of UTI in humans based on decreased adhesion of UPEC to uroepithelial cells. The present study evaluated the impact of cranberry extract addition on the attachment of UPEC to canine Madin-Darby Canine Kidney and Crandell-Rees Feline Kidney uroepithelial cells. When the extract was present during bacterial growth or only during adhesion tests, a dose-dependent decrease of UPEC adhesion to all cell types was observed. Bacterial growth was weakly decreased only in the presence of the highest concentration of cranberry extract showing that the anti-adherence effect did not require a bacterial growth inhibitory effect. In conclusion, the addition of cranberry extract has preventive effects on the in vitro bacterial attachment to canine and feline uroepithelial cells in a dose dependent way.

Uropathogenic Escherichia coli (UPEC), the most prevalent bacteria isolated in urinary tract infections (UTI), is now frequently resistant to antibiotics used to treat this pathology. The antibacterial properties of cranberry and propolis could reduce the frequency of UTIs and thus the use of antibiotics, helping in the fight against the emergence of antibiotic resistance. Transcriptomic profiles of a clinical UPEC strain exposed to cranberry proanthocyanidins alone (190micro g/mL), propolis alone (102.4micro g/mL) and a combination of both were determined. Cranberry alone, but more so cranberry+propolis combined, modified the expression of genes involved in different essential pathways: down-expression of genes involved in adhesion, motility, and biofilm formation, and up-regulation of genes involved in iron metabolism and stress response. Phenotypic assays confirmed the decrease of motility (swarming and swimming) and biofilm formation (early formation and formed biofilm). This study showed for the first time that propolis potentiated the effect of cranberry proanthocyanidins on adhesion, motility, biofilm formation, iron metabolism and stress response of UPEC. Cranberry+propolis treatment could represent an interesting new strategy to prevent recurrent UTI.

The defense against influenza virus (IV) infections still poses a series of challenges. The current antiviral arsenal against influenza viruses is in fact limited; therefore, the development of new anti-influenza strategies effective against antigenically different viruses is an urgent priority. Bioactive compounds derived from medicinal plants and fruits may provide a natural source of candidates for such broad-spectrum antivirals. In this regard, cranberry (Vaccinium macrocarpon Aiton) extracts on the basis of their recognized anti-adhesive activities against bacteria, may provide potential compounds able to prevent viral attachment to target cells. Nevertheless, only few studies have so far investigated the possible use of cranberry extracts as an antiviral tool. This study focuses on the suitability of a cranberry extract as a direct-acting anti-influenza compound. We show that the novel cranberry extract Oximacro inhibits influenza A and B viruses (IAV, IBV) replication in vitro because of its high content of A-type proanthocyanidins (PAC-A) dimers and trimers. Mechanistic studies revealed that Oximacro prevents attachment and entry of IAV and IBV into target cells and exerts a virucidal activity. Oximacro was observed to interact with the ectodomain of viral hemagglutinin (HA) glycoprotein, thus suggesting the interference with HA functions and a consequent loss of infectivity of IV particles. Fluorescence spectroscopy revealed a reduction in the intrinsic fluorescence of HA protein after incubation with purified dimeric PAC-A (PAC-A2), thus confirming a direct interaction between HA and Oximacro PAC-A2. In silico docking simulations further supported the in vitro results and indicated that among the different components of the Oximacro chemical profile, PAC-A2 exhibited the best binding propensity with an affinity below 10 nM. The role of PAC-A2 in the anti-IV activity of Oximacro was eventually confirmed by the observation that it prevented IAV and IVB replication and caused the loss of infectivity of IV particles, thus indicating PAC-A2 as the major active component of Oximacro. As a whole, these results suggest Oximacro as a potential candidate to create novel antiviral agents of natural origin for the prevention of IV infections.

Background: Urinary tract infection is the most common bacterial infection in the community, mainly caused by Escherichia coli (E. coli). Due to its high incidence and recurrence, problems are faced in the treatment with antibiotics. Cranberry being herbal remedy have long been the focus of interest for their beneficial effects in preventing urinary tract infections. This study was conducted to analyse in vitro activity of cranberry (Vaccinium macrocarpon) on uropathogenic E. coli in uncomplicated urinary tract infections. Methods: In this laboratory based single group experimental study, anti-bacterial activity of Vaccinium macrocarpon concentrate on urinary tract E. coli was investigated, in vitro. Ninety-six culture positive cases of different uropathogens were identified. Vaccinium macrocarpon concentrate at different concentrations was prepared in distilled water and put in wells punched in nutrient agar. E. coli isolates were inoculated on the plates and incubated at 37 oC for 24 hours. A citric acid solution of the same pH as that of Vaccinium macrocarpon was used and put in a well on the same plate to exclude the effect of pH. Results: A total of 35 isolates of E. coli were identified out of 96 culture positive specimens of urine and found sensitive to Vaccinium macrocarpon (p<0.000). Results revealed that Vaccinium macrocarpon has antibacterial effect against E. coli. Furthermore the antibacterial activity of Vaccinium macrocarpon has dose response relationship. Acidic nature of Vaccinium macrocarpon due to its pH is not contributory towards its antibacterial effect. Conclusion: Vaccinium macrocarpon concentrate may be used in urinary tract infection caused by E. coli.

Cranberry consumption has shown prophylactic effects against urinary tract infections (UTI), although the mechanisms involved are not completely understood. In this paper, cranberry phenolic compounds and their potential microbial-derived metabolites (such as simple phenols and benzoic, phenylacetic and phenylpropionic acids) were tested for their capacity to inhibit the adherence of uropathogenic Escherichia coli (UPEC) ATCC53503TM to T24 epithelial bladder cells. Catechol, benzoic acid, vanillic acid, phenylacetic acid and 3,4-dihydroxyphenylacetic acid showed anti-adhesive activity against UPEC in a concentration-dependent manner from 100-500 micro M, whereas procyanidin A2, widely reported as an inhibitor of UPEC adherence on uroepithelium, was only statistically significant (p < 0.05) at 500 micro M (51.3% inhibition). The results proved for the first time the anti-adhesive activity of some cranberry-derived phenolic metabolites against UPEC in vitro, suggesting that their presence in the urine could reduce bacterial colonization and progression of UTI.

Cranberry juice has been recognized as a treatment for urinary tract infections on the basis of scientific reports of proanthocyanidin anti-adhesion activity against Escherichia coli as well as from folklore. Xyloglucan oligosaccharides were detected in cranberry juice and the residue remaining following commercial juice extraction that included pectinase maceration of the pulp. A novel xyloglucan was detected through tandem mass spectrometry analysis of an ion at m/z 1055 that was determined to be a branched, three hexose, four pentose oligosaccharide consistent with an arabino-xyloglucan structure. Two-dimensional nuclear magnetic resonance spectroscopy analysis provided through-bond correlations for the alpha-l-Araf (1->2) alpha-d-Xylp (1->6) beta-d-Glcp sequence, proving the S-type cranberry xyloglucan structure. Cranberry xyloglucan-rich fractions inhibited the adhesion of E. coli CFT073 and UTI89 strains to T24 human bladder epithelial cells and that of E. coli O157:H7 to HT29 human colonic epithelial cells. SSGG xyloglucan oligosaccharides represent a new cranberry bioactive component with E. coli anti-adhesion activity and high affinity for type 1 fimbriae.

Pseudomonas aeruginosa colonizes the lungs in cystic fibrosis (CF) and mechanically ventilated patients by binding to the cellular receptors on the surface of the lung epithelium. Studies have shown that blocking this interaction could be achieved with sub-minimum inhibitory concentrations of antibiotics such as ciprofloxacin. The development of bacterial resistance is a probable drawback of such an intervention. The use of natural extracts to interfere with bacterial adhesion and invasion has recently gained substantial attention and is
hypothesized to inhibit bacterial binding and consequently prevent or reduce pathogenicity. This study used an A549 lung epithelial cell infection model, and the results revealed that a combination of aqueous cranberry extract with ciprofloxacin could completely prevent the adhesion and invasion of P. aeruginosa PAO1 compared to the untreated control. All of the natural extracts (cranberry, dextran, and soybean extracts) and ciprofloxacin showed a significant reduction (P0.0001) in P. aeruginosa PAO1 adhesion to and invasion of lung epithelial
cells relative to the control. The cranberry, dextran, and soybean extracts could substantially increase the anti-adhesion and anti-invasion effects of ciprofloxacin to the averages of 100% (P0.0001), 80% (P0.0001), and 60%
(P0.0001), respectively. Those extracts might result in a lower rate of the development of bacterial resistance; they are relatively safe and inexpensive agents, and utilizing such extracts, alone or in combination with ciprofloxacin,
as potential anti-adhesion and anti-invasion remedies, could be valuable in preventing or reducing P. aeruginosa lung infections.

SCOPE: A major portion of ingested procyanidins is degraded by human microbiota in the colon into various phenolic compounds. These microbial metabolites are thought to contribute to the health benefits of procyanidins in vivo. The
objective of this study was to identify and quantify the microbial metabolites of procyanidins after anaerobic fermentation with human microbiota.
METHODS AND RESULTS: (-)-Epicatechin, (+)-catechin, procyanidin B2, procyanidin A2, partially purified apple and cranberry procyanidins were incubated with human
microbiota at a concentration equivalent to 0.5 mM epicatechin. GC-MS analysis showed that common metabolites of all six substrates were benzoic acid, 2-phenylacetic acid, 3-phenylpropionic acid, 2-(3'-hydroxyphenyl)acetic acid,
2-(4'-hydroxyphenyl)acetic acid, 3-(3'-hydroxyphenyl)propionic acid, and hydroxyphenylvaleric acid. 5-(3',4'-Dihydroxyphenyl)-γ-valerolactones and 5-(3'-hydroxyphenyl)-γ-valerolactones were identified as the microbial metabolites of epicatechin, catechin, procyanidin B2, and apple procyanidins but not from the procyanidin A2 or cranberry procyanidin ferments. 2-(3',4'-Dihydroxyphenyl)acetic acid was only found in the fermented broth of procyanidin B2, A2, apple, and cranberry procyanidins. The mass recoveries of microbial metabolites range from 20.0 to 56.9% for the six substrates after 24 h
of fermentation.
CONCLUSION: Procyanidins, both B-type and A-type can be degraded by human gut microbiota. The microbial metabolites may contribute to the bioactivities of procyanidins.