Three proanthocyanidin trimers possessing A-type interflavanoid linkages, epicatechin-(4beta-->6)-epicatechin-(4beta-->8, 2beta-->O-->7)-epicatechin (4), epicatechin-(4beta-->8, 2beta-->O-->7)-epicatechin-(4beta-->8)-epicatechin (5), and epicatechin-(4beta-->8)-epicatechin-(4beta-->8, 2beta-->O-->7)-epicatechin (6), were isolated from the ripe fruits of Vaccinium macrocarpon (cranberry) and prevented adherence of P-fimbriated Escherichia coli isolates from the urinary tract to cellular surfaces containing alpha-Gal(1-->4)beta-Gal receptor sequences similar to those on uroepithelial cells. The structure of 4 was elucidated by a combination of spectroscopic methods and acid-catalyzed degradation with phloroglucinol. Also isolated were the weakly active epicatechin-(4beta-->8, 2beta-->O-->7)-epicatechin (procyanidin A2) (3) and the inactive monomer epicatechin (1) and the inactive dimer epicatechin-(4beta-->8)-epicatechin (procyanidin B2) (2).

BACKGROUND AND AIM: Cranberry is a fruit that originated in North America, and it has been used by Native Americans for bacterial infections. Recent studies have revealed it to be effective for preventing refractory urinary infections, while also suggesting that it plays a possible role in the eradication of Helicobacter pylori (H. pylori).

METHODS: The H. pylori strains used in the present study were NCTC11637 and 11638. Sugar and organic acid-rich, and polyphenol-rich fractions were obtained from cranberry juice concentrate by Amberlite XAD7HP-column chromatography. The H. pylori growth inhibition was estimated by OD(660) and titration in liquid culture, and by an agar dilution plate method. The shapes of the bacteria were analyzed by scanning electron microscopy.

RESULTS: Cranberry extract suppressed bacterial proliferation in a dose-dependent manner. In the comparison with other juices, polyphenol-rich fruits (cranberries, blueberries, and red grapes) showed similar growth inhibitory activity, whereas polyphenol-poor fruits (oranges, pineapples, apples, and white grapes) did not show any activity. The polyphenol-rich fraction of cranberry maintained the H. pylori-growth inhibitory activity. More bacteria in a coccoid form were observed after culture with cranberry.

CONCLUSION: Cranberry extract inhibited H. pylori proliferation and it is suggested that polyphenols are responsible for this action. The morphological analysis suggested that cranberry induces H. pylori to develop a coccoid form, thereby inhibiting its growth bacteriostatically. Further basic studies to clarify these mechanisms in combination with in vivo studies are needed.

The objective of this study was to evaluate the effects of various berry extracts, with and without clarithromycin on Helicobacter pylori. Resistance to clarithromycin by H. pylori has been reported, leading to interest in alternatives/adjuncts to therapy with clarithromycin. H. pylori American type culture collection (ATCC) strain 49503 was grown, cell suspensions were made in
PBS and diluted 10-fold. One hundred μl of the suspension was then incubated for 18 h with extracts of raspberry, strawberry, cranberry, elderberry, blueberry, bilberry, and OptiBerry R , a blend of the six berries, at 0.25–1% concentrations. Serially diluted cell suspensions were exposed for 1 h to clarithromycin at 15 μg/ml. Ten μl of bacterial samples from the 10–7 dilution tube
were plated and incubated for 18 h and the number of colonies were counted. Growth of H. pylori was confirmed by the CLO R test. All berry extracts significantly (p 0.05) inhibited H. pylori, compared with controls, and also increased susceptibility of H. pylori to clarithromycin, with OptiBerry R demonstrating maximal effects.

Previous clinical research has suggested that the consumption of cranberry products prevents the adhesion of Escherichia coli to uroepithelial cells by causing changes in bacterial fimbriae. Atomic force microscopy was used to probe the adhesion forces between E. coli (nonfimbriated strain HB101 and the P-fimbriated variant HB101pDC1) and a model surface (silicon nitride), to determine the effect of growth in cranberry products on bacterial adhesion. Bacteria were grown in tryptic soy broth supplemented with either light cranberry juice cocktail (L-CJC) or cranberry proanthocyanidins (PACs). Growth of E. coli HB101pDC1 and HB101 in L-CJC or PACs resulted in a decrease in adhesion forces with increasing number of cultures. In a macroscale bacteria-uroepithelial cell adhesion assay a decrease in bacterial attachment was observed for E. coli HB101pDC1 grown in L-CJC or PACs. This effect was reversible because bacteria that were regrown in cranberry-free medium regained their ability to attach to uroepithelial cells, and their adhesion forces reverted to the values observed in the control condition. Exposure to increasing concentrations of L-CJC resulted in a decrease of bacterial attachment to uroepithelial cells for the P-fimbriated strain after L-CJC treatment (27% by weight) and after PACs treatment (345.8 microg/mL). Cranberry products affect the surface properties, such as fimbriae and lipopolysaccharides, and adhesion of fimbriated and nonfimbriated E. coli. The concentration of cranberry products and the number of cultures the bacteria were exposed to cranberry determines how much the adhesion forces and attachment are altered.

The effect of cranberry juice (CJ) and cranberry proanthocyanidins (PAC) on the infectivity of human enteric virus surrogates, murine norovirus (MNV-1), feline calicivirus (FCV-F9), MS2(ssRNA) bacteriophage, and phiX-174(ssDNA) bacteriophage was studied. Viruses at high (approximately 7 log(10) PFU/ml) or low (approximately 5 log(10) PFU/ml) titers were mixed with equal volumes of CJ, 0.30, 0.60, and 1.20 mg/ml final PAC concentration, or water and incubated for 1 h at room temperature. Viral infectivity after treatments was evaluated using standardized plaque assays. At low viral titers, FCV-F9 was undetectable after exposure to CJ or the three tested PAC solutions. MNV-1 was reduced by 2.06 log(10) PFU/ml with CJ, and 2.63, 2.75, and 2.95 log(10) PFU/ml with 0.15, 0.30, and 0.60 mg/ml PAC, respectively. MS2 titers were reduced by 1.14 log(10) PFU/ml with CJ, and 0.55, 0.80, and 0.96 log(10) PFU/ml with 0.15, 0.30, and 0.60 mg/ml PAC, respectively. phi-X174 titers were reduced by 1.79 log(10) PFU/ml with CJ, and 1.95, 3.67, and 4.98 log(10) PFU/ml with PAC at 0.15, 0.30, and 0.60 mg/ml, respectively. Experiments using high titers showed similar trends but with decreased effects. CJ and PAC show promise as natural antivirals that could potentially be exploited for foodborne viral illness treatment and prevention.

The purpose of this study was to investigate the effect of cranberry polyphenol fraction on mutans streptococci. Hydrophobicity is an important factor in the adherence of bacteria to the tooth surface. We found that cranberry polyphenol fraction significantly decreased the hydrophobicity of Streptococcus sobrinus 6715, Streptococcus mutans MT8148R and JC2 in a dose-dependent manner (p0.05). Biofilm formation by S. sobrinus 6715 and S. mutans MT8148R was inhibited by 100 microg/ml cranberry polyphenol fraction (p0.01). When dosage was increased to 500 microg/ml, biofilm formation by S. mutans JC2 was significantly inhibited (p0.05). Addition of 500 microg/ml cranberry polyphenol fraction to medium inhibited growth of S. mutans MT8148R compared with the control (p0.05).

Studies were performed to investigate the effect of several cranberry and grape juice extracts on the inhibition of reovirus infectivity following cell culture inoculation. Infectivity testing was performed utilizing cranberry juice extracts NutriCran-100TM and NutriCran-90TM. At 5% extract concentrations, titers were reduced by ca. 50%. Cranberry cocktail juice caused an infectivity loss of ca. 10%. We ascribe these data to higher concentrations of proanthocyanidins (PACs) in the cranberry extracts.
Further testing was performed utilizing purified high and low molecular weight cranberry PAC fractions (CB HMW and CB LMW, respectively), a cranberry flavonol glycoside (CB EToAc), cranberry anthocyanins (CB CA), and a grape PAC extract. Reovirus titers were reduced to undetectable levels at PAC concentrations f0.2%. CB CA had no effect on the inhibition of infectivity titers. Loss of infectivity titers was in the order: GP PACACB HMWACB LMWACB EToAc. Probe homogenization of CB HMWenhanced the extract to efficacy levels equal to that of grape PAC. Reovirus dsRNA segments were undetectable 96-h postcranberry cocktail juice pretreatment of MA-104 cell cultures. This study indicates an inhibition of reovirus infectivity titers by cranberry or grape juices or their purified PAC extracts. Viral inhibition probably occurs at the host cell surface.

Periodontitis is a chronic inflammatory disease that affects the tooth supporting tissues. Gingival fibroblasts are the most abundant cells in periodontal tissues and participate actively in the host inflammatory response to periodontopathogens, which is known to mediate local tissue destruction in periodontitis. The aim of this study was to investigate the effect of a proanthocyanidin-enriched cranberry fraction, prepared from cranberry juice concentrate, on inflammatory mediator production by gingival fibroblasts stimulated by the lipopolysaccharide (LPS) of Aggregatibacter actinomycetemcomitans. Interleukin (IL)-6, IL-8, and prostaglandin E(2) (PGE(2)) production by fibroblasts treated with the cranberry fraction and stimulated by A. actinomycetemcomitans LPS was evaluated by enzyme-linked immunosorbent assay. Changes induced by A. actinomycetemcomitans LPS and the cranberry fraction in the expression and phosphorylation state of fibroblast intracellular signaling proteins were characterized by antibody microarrays. The LPS-induced IL-6, IL-8, and PGE(2) responses of gingival fibroblasts were inhibited by treatment with the cranberry fraction. This fraction was found to inhibit fibroblast intracellular signaling proteins, a phenomenon that may lead to a down-regulation of activating protein-1 activity. Cranberry components also reduced cyclooxygenase 2 expression. This study suggests that cranberry juice contains molecules with interesting properties for the development of new host-modulating therapeutic strategies in the adjunctive treatment of periodontitis.

We investigated the antimicrobial effect of constituents of the American cranberry (Vaccinium macrocarpon); sugar plus organic acids, phenolics, and anthocyanins, against Escherichia coli O157:H7. Each fractional component was assayed over a 24-h period with 5-log initial inocula to determine the minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC), and log CFU/ml reductions, at their native pH and neutral pH. Each fraction produced significant reductions (P0.05) at the native pH: MICs for sugars plus organic, phenolics, and anthocyanins were 5.6/2.6 Brix/acid (citric acid equivalents) 2.70g/L (gallic acid equivalent), and 14.80mg/L (cyanidin-3-glucoside equivalent), respectively. Sugars plus organic acids at native pH (3) produced a reduction below detectable limits (1 log CFU/ml) compared to the control at 24h for 11.3/5.2 and 5.6/2.6 Brix/acid. Phenolics at native pH (4) produced reductions below detectable limits compared to the control at 24h and initial inocula for treatments of 5.40 and 2.70g/L. Anthocyanins at native pH (2) produced reductions below detectable limits for treatments of 29.15 and 14.80mg/L cyanidin-3-glucoside equivalents. Neutralized phenolics and anthocyanins had the same MIC and MBC as those at their native pH. Neutralized sugars plus organic acids did not inhibit bacterial growth compared to the control. Neutralized phenolics reduced bacteria below detectable limits in treatments of 5.40g/L and 2.70g/L compared to the control. Neutralized anthocyanins reduced bacterial growth below detectable limits at the concentration of 29.15mg/L, but at 14.80mg/L there was no significant reduction. Stationary-phase cells of E. coli O157:H7 were treated with 5% of each fraction in 0.8% NaCl for 20min and viewed under transmission electron microscopy. All fractions caused significant damage compared the control. Sugars plus organic acids caused visible osmotic stress, while phenolics and anthocyanins caused disintegration of the outer membrane.