Cranberries (Vaccinium macrocarpon) represent an important source of anthocyanins, flavan-3-ols and flavonols. This study aimed at investigating in vitro the human microbial metabolism of (poly)phenols, principally flavan-3-ols, of unformulated- and phytosome-formulated cranberry extracts. After powder characterization, a 24-h fermentation with human faecal slurries was performed, standardizing the concentration of incubated proanthocyanidins. Cranberry (poly)phenol metabolites were quantified by uHPLC-MS2 analyses. The native compounds of both unformulated- and phytosome-formulated cranberry extracts were metabolized under faecal microbiota activity, resulting in twenty-four microbial metabolites. Although some differences appeared when considering different classes of colonic metabolites, no significant differences in the total amount of metabolites were established after 24 h of incubation period. These results suggested that a different formulation had no effect on flavan-3-ol colonic metabolism of cranberry and both unformulated- and phytosome-formulated extract. Both formulations displayed the capability to be a potential source of compounds which could lead to a wide array of gut microbiota metabolites in vitro.

BACKGROUND: The oral microbiota is a significant risk indicator for oral diseases, such as dental caries and periodontal inflammation. Much attention is presently paid to the development of functional foods (e.g. beverages containing cranberry constituents, or foods containing probiotics) that may serve as adjuncts for oral disease treatments (e.g. periodontitis and caries). Cranberry fruit, due to its unique chemical composition and antimicrobial potential, is a possible ingredient of such foods. The study aimed to investigate the effects of cranberry juice (CJ) and a cranberry functional beverage (mixture of 80% v/v apple juice, 20% v/v cranberry juice, and 0.25 g/100 mL ground cinnamon; CFB) on the growth and metabolic activity of selected oral bacteria.METHODS: Serial dilution pour plate method (SDPP) was used to examine the effect of CJ and CFB on the growth of Actinomyces naeslundii, Streptococcus mutans, and Lactobacillus paracasei subsp. paracasei. 48-h electrical impedance measurements (EIM) during the cultivation of A. naeslundii were applied to evaluate the utility of the method as a rapid alternative for the assessment of the antimicrobial potential of cranberry beverages.RESULTS: The tested bacteria differed in their susceptibility to the antimicrobial action of CJ and CFB, with L. paracasei subsp. paracasei being least vulnerable to CFB (according to SDPP). Although CJ at a concentration of 0.5 mL/mL, showed a bactericidal effect on the growth of S. mutans, A. naeslundii was more sensitive to CJ (SDPP). Its inhibitory effect on A. naeslundii was seen even at concentrations as small as 0.03125-0.125 mL/mL (SDPP and EIM). On the other hand, S. mutans seemed to be more vulnerable to CFB than A. naeslundii (SDPP).CONCLUSIONS: CFB may be considered an adjunct in the treatment of oral diseases due to its action against selected oral pathogens, and not against the presumably beneficial L. paracasei subsp. paracasei. Bioelectrical impedance measurements appear to be a quick alternative to evaluating the antimicrobial activity of fruit beverages, but their utility should be confirmed with tests on other bacteria.

The secondary metabolite content of cranberry fruits can vary with cultivar and environmental factors, which may in turn impact their potential biological activities. To evaluate the influence of composition on anti-inflammatory activity, cranberry fruits were collected from two major U.S. growing regions. Eight extracts from these fruits were prepared, analyzed for phytochemical composition, and evaluated for their anti-inflammatory effects in human monocytes (THP-1 cells). The extracts varied widely in polyphenol and triterpenoid content. All were able to reduce lipopolysaccharide (LPS)-induced production of pro-inflammatory cytokine interleukin 6 (IL-6) at 100 μg/mL, with inhibition ranging between 18.8 and 48.8%. Of these, three extracts high in anthocyanins, triterpenoids, or total polyphenols decreased levels of IL-6 and tumor necrosis factor alpha (TNF-α) at concentrations of 0.1–10 μg/mL compared to LPS-exposed control. Several individual cranberry phytochemicals were also capable of reducing production of IL-6, IL-1β, and TNF-α. The data suggest that phytochemicals present in varying quantities in cranberry fruits including anthocyanins, hyperoside, ursolic acid, and corosolic acid play a role in the anti-inflammatory effects of cranberry extracts on human monocytes.

This study aimed to evaluate and compare the dried pomace powder of cranberries, lingonberries, sea buckthorns, and black currants as potential food ingredients with functional properties. The composition and several physicochemical and adsorption properties associated with their functionality were investigated. Tested berry pomace powders were rich in dietary soluble fiber (4.92-12.74 g/100 g DM) and insoluble fiber (40.95-65.36 g/100 g DM). The highest level of total phenolics was observed in the black currant pomace (11.09 GAE/g DM), whereas the sea buckthorn pomace revealed the highest protein concentration (21.09 g/100 g DM). All the berry pomace powders that were tested exhibited good water-holding capacity (2.78-4.24 g/g) and swelling capacity (4.99-9.98 mL/g), and poor oil-binding capacity (1.09-1.57 g/g). The strongest hypoglycemic properties were observed for the lingonberry and black currant pomace powders. The berry pomace powders presented effective in vitro hypolipidemic properties. The cholesterol-binding capacities ranged from 21.11 to 23.13 mg/g. The black currant and cranberry pomace powders demonstrated higher sodium-cholate-binding capacity than those of the lingonberry and sea buckthorn pomace powders. This study shows promising results that the powders of tested berry pomace could be used for further application in foods.

Scope: The molecular basis underlying the anti-inflammatory and anticarcinogenic properties of cranberries is incompletely understood. The effects of a cranberry proanthocyanidin-rich extract (PAC) and two of its gut microbial metabolites, 3,4-dihydroxyphenylacetic acid (DHPAA) and 3-(4-hydroxyphenyl)-propionic acid (HPPA), on intestinal epithelial cells microRNA (miRNA) expression and their downstream pathways at homeostasis and in inflammatory conditions, are investigated.Methods and Results: The expression of 799 miRNAs is quantitatively assessed in differentiated Caco-2BBe1 cells pre-treated with PAC, DHPAA, or HPPA and stimulated with interleukin (IL)-1 beta or not. PAC, DHPAA, and HPPA generate subsets of shared and distinct miRNA responses. At homeostasis, miRNAs affected by the metabolites, but not PAC, targeted genes enriched in kinase, Wnt, and growth factor signaling, cell growth and proliferation, apoptosis, and specific cancer pathways. In an inflammatory environment, PAC and DHPAA, but not HPPA, reverses the expression of 16 and two IL-1 beta-induced miRNAs, respectively, regulating inflammatory and cancer pathways.Conclusion: miRNA modulation is a novel mechanism for PAC bioactivity in the gut. The gut microbiota may be necessary to unlock these effects at homeostasis and partially in inflammation.

Cranberry volatiles have received little attention for health-promoting properties. In this study, we compared the inhibitory effects of cranberry polyphenol and volatile extracts and volatile standards on nitric oxide (NO) production in lipopolysaccharide (LPS) activated RAW 264.7 macrophages. Polyphenols were analyzed by HPLC/HPLC-MS and volatiles were analyzed by GC/GC-MS. The inhibition of NO production of the fresh cranberry polyphenol and volatile extracts and alpha -terpineol, linalool, linalool oxide, and eucalyptol standards at 2, 4, and 8-fold dilutions of their original concentrations in fresh cranberries was evaluated by treating these extracts/standards for 1 h before or after LPS application for 24 h. After inducing inflammation with LPS, the polyphenol treatments (317.8 and 635.7 micro g g-1) and 1.8 micro g g-1 volatile treatment lowered NO levels 46-62% compared to the positive control (P<0.05). When the cells were treated with polyphenol and volatile extracts before inducing inflammation, the 635.7 micro g g-1 and 317.8 micro g g-1 polyphenol treatments and 1.8 micro g g-1 and 0.9 micro g g-1 volatile treatments lowered NO levels (13-52%) compared to the positive control (P<0.05). Polyphenol and volatile extracts from cranberry were effective in reducing NO production whether applied before or after the application of LPS. alpha -Terpineol at a concentration found in fresh cranberries (1.16 micro g mL-1) was also found to be effective in reducing NO production whether cells were treated before or after application of LPS. Future studies are needed to reveal the mechanisms by which volatile compounds, especially alpha -terpineol act to mitigate inflammation and to determine the bioavailability of terpenes.

Cranberry ( Vaccinium macrocarpon) products are widely available in North American food, juice, and dietary supplement markets. The use of cranberry is popular for the prevention of urinary tract infections (UTIs) and other reported health benefits. Preliminary findings by our research group indicate that arabinoxyloglucan oligosaccharides are present in cranberry products and may contribute to the antiadhesion properties of urine produced after cranberry consumption, but relatively little is known regarding the oligosaccharide components of cranberry. This report describes the isolation from two cranberry sources and the complete structure elucidation of two arabinoxyloglucan oligosaccharides through the use of carbohydrate-specific NMR spectroscopic and chemical derivatization methods. These compounds were identified as the heptasaccharide beta-d-glucopyranosyl-(1->4)-[alpha-d-xylopyranosyl-(1->6)]-beta-d-glucopyranosyl-(1->4)-beta-d-glucopyranosyl-(1->4)-[alpha-l-arabinofuranosyl-(1->2)-alpha-d-xylopyranosyl-(1->6)]-beta-d-glucopyranose (1) and the octasaccharide beta-d-glucopyranosyl-(1->4)-[alpha-l-arabinofuranosyl-(1->2)-alpha-d-xylopyranosyl-(1->6)]-beta-d-glucopyranosyl-(1->4)-beta-d-glucopyranosyl-(1->4)-[alpha-l-arabinofuranosyl-(1->2)-alpha-d-xylopyranosyl-(1->6)]-beta-d-glucopyranose (2). Selected fractions and the isolated compounds were subjected to antimicrobial, cell viability, and E. coli antiadhesion assays. Results indicated that enriched fractions and purified compounds lacked antimicrobial and cytotoxic effects, supporting the potential use of such compounds for disease prevention without the risk for resistance development. Preliminary antiadhesion results indicated that mixtures of oligosaccharides exhibited greater antiadhesion properties than purified fractions or pure compounds. The potential use of cranberry oligosaccharides for the prevention of UTIs warrants continued investigations of this complex compound series.

To study the anti-inflammatory effect of cranberry extract on inflammation suppression induced by lipopolysaccharide, and explore its mechanism. Cell inflammatory model was established with RAW264.7 cells treated with lipopolysaccharide. Cell viability of RAW264.7 cells treated with cranberry extract were analyzed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. The effect of cranberry extract on nucleus was observed by 4',6-diamidino-2-phenylindole(DAPI)staining. The activity of nitric oxide synthase (NOS) was determined by fluorescence analysis. Enzyme-linked immunosorbent assay (ELISA) for determination of IL-1 beta , IL-6 and TNF- alpha . RAW264.7 cells were treated with cranberry extract for 24 h, and the expression of Keap1, Nrf2, HO-1, IKK alpha / beta and NF- kappa Bp65 were detected by Western blotting. The result showed that the inflammatory model was established by 5 micro g/mL lipopolysaccharide, the highest level of inflammation was reached at 24 hours. There was no significant toxic effect on RAW246.7 cells in the range of 5 micro g/mL-400 micro g/mL, and the cell nucleus was intact and without obvious damage. Compared with the model group, cranberry extract could significantly inhibit the activity of NOS and decreased the content of IL-1 beta , IL-6, TNF- alpha with the increase of dose. The Western blot result showed that cranberry extract inhibited the expression of Keap1, IKK alpha / beta , NF- kappa Bp65 and increase the expression of Nrf2 and HO-1 protein levels. These results suggest that cranberry extract can inhibit the inflammatory response induced by lipopolysaccharide, and its mechanism may be related to activation of Keap1/Nrf2/HO-1 signaling pathway and NF- kappa Bp65.

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.

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.