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Urinary Tract Health and Antibacterial Benefits: In-Vitro

Displaying 21 - 30 of 111

The specific degree-of-polymerization of A-type proanthocyanidin oligomers impacts Streptococcus mutans glucan-mediated adhesion and transcriptome responses within biofilms

Posted: 
September 15, 2013
Authors: 
Feng G, Klein MI, Gregoire S, Singh AP, Vorsa N, Koo H
Journal: 
Biofouling 29(6):629-40
Abstract: 

Cranberry A-type proanthocyanidins (PACs) have been recognized for their inhibitory activity against bacterial adhesion and biofilm-derived infections. However, the precise identification of the specific classes of degree-of-polymerization (DP) conferring PACs bioactivity remains a major challenge owing to the complex chemistry of these flavonoids. In this study, chemically characterized cranberries were used in a multistep separation and structure-determination technique to isolate A-type PAC oligomers of defined DP. The influences of PACs on the 3D architecture of biofilms and Streptococcus mutans-transcriptome responses within biofilms were investigated. Treatment regimens that simulated topical exposures experienced clinically (twice-daily, 60s each) were used over a saliva-coated hydroxyapatite biofilm model. Biofilm accumulation was impaired, while specific genes involved in the adhesion of bacteria, acid stress tolerance, and glycolysis were affected by the topical treatments (vs the vehicle-control). Genes (rmpC, mepA, sdcBB, and gbpC) associated with sucrose-dependent binding of bacteria were repressed by PACs. PACs of DP 4 and particularly DP 8 to 13 were the most effective in disrupting bacterial adhesion to glucan-coated apatitic surface (>85% inhibition vs vehicle control), and gene expression (eg rmpC). This study identified putative molecular targets of A-type cranberry PACs in S. mutans while demonstrating that PAC oligomers with a specific DP may be effective in disrupting the assembly of cariogenic biofilms.

Capability of Lactobacillus plantarum IFPL935 To Catabolize Flavan-3-ol Compounds and Complex Phenolic Extracts

Posted: 
October 30, 2012
Authors: 
Sanchez-Patan F, Tabasco R, Monagas M, Requena T, Pelaez C, Moreno-Arribas MV, Bartolome B
Journal: 
J Agric Food Chem 60(29):7142-51
Abstract: 

Lactobacillus plantarum IFPL935 was incubated with individual monomeric flavan-3-ols and dimeric A- and B-type procyanidins to identify new metabolites and to determine the effect of compound structural features on bacterial growth and catabolism. Complex extracts rich in A-type proanthocyanidins and phenolic acids from cranberry were also tested. The results showed that L. plantarum IFPL935 exhibited higher resistance to nongalloylated monomeric flavan-3-ols, A-type dimeric procyanidins, and cranberry extract than to (−)-epicatechin-3-O-gallate and B-type dimeric procyanidins. Despite these findings, the strain was capable of rapidly degrading (−)-epicatechin-3-O-gallate, but not A- or B-type dimeric procyanidins. However, it
was able to produce large changes in the phenolic profile of the cranberry extract mainly due to the catabolism of
hydroxycinnamic and hydroxybenzoic acids. Of most relevance was the fact that L. plantarum IFPL935 cleaved the heterocyclic ring of monomeric flavan-3-ols, giving rise to 1-(3′,4′-dihydroxyphenyl)-3-(2″,4″,6″-trihydroxyphenyl)propan-2-ol, activity exhibited by only a few human intestinal bacteria.

Effects of a Variety of Food Extracts and Juices on the Specific Binding Ability of Norovirus GII.4 P Particles

Posted: 
October 30, 2012
Authors: 
Li D, Baert L, Xia M, Zhong W, Jiang X, Uyttendaele M
Journal: 
J Food Prot 75(7): 1350-4
Abstract: 

The effects of 13 food extracts and juices, including shellfish, fruits, and vegetables, on the binding ability of human norovirus (NoV) were examined, using P particles of human NoV GII.4 as a research surrogate. The enhancements (positive values) or reductions (negative values) of NoV P particle detection (changes in optical density at 450 nm) in the presence of different
food extracts and juices as compared with P particles diluted in phosphate-buffered saline were tested by saliva-binding, enzymelinked immunosorbent assay in triplicate. In the presence of different food extracts and juices at different concentrations, an increase or decrease of the receptor-binding ability of the NoV P particles was observed. Due to a higher specific binding and thus a higher
accumulation of the viral particles, oysters may be contaminated with human NoV more often than other shellfish species (mussel, hard clams, and razor clams). Cranberry and pomegranate juices were shown to reduce the specific binding ability of human NoV P particles. No such binding inhibition effects were observed for the other tested extracts of fresh produce (strawberry, blackberry,
blueberry, cherry tomato, spinach, romaine lettuce) or, notably, for raspberry, which has been associated with human NoV outbreaks.

Tannin derived materials can block swarming motility and enhance biofilm formation in Pseudomonas aeruginosa

Posted: 
October 30, 2012
Authors: 
O'May C, Ciobanu A, Lam H, Tufenkiji N
Journal: 
Biofouling 28(10):1063-76
Abstract: 

Surface-associated swarming motility is implicated in enhanced bacterial spreading and virulence, hence it follows
that anti-swarming effectors could have clinical benefits. When investigating potential applications of anti-swarming
materials it is important to consider whether the lack of swarming corresponds with an enhanced sessile biofilm
lifestyle and resistance to antibiotics. In this study, well-defined tannins present in multiple plant materials (tannic
acid (TA) and epigallocathecin gallate (EGCG)) and undefined cranberry powder (CP) were found to block swarming motility and enhance biofilm formation and resistance to tobramycin in Pseudomonas aeruginosa. In contrast, gallic acid (GA) did not completely block swarming motility and did not affect biofilm formation or tobramycin resistance. These data support the theory that nutritional conditions can elicit an inverse relationship between swarming motility and biofilm formation capacities. Although anti-swarmers exhibit the potential to yield clinical benefits, it is important to be aware of possible implications regarding biofilm formation and antibiotic resistance.

Antibacterial effects of plant-derived extracts on methicillin-resistant Staphylococcus aureus.

Posted: 
July 31, 2012
Authors: 
Su XW, Howell AB, D'Souza DH
Journal: 
Foodborne Pathog Dis 9(6):573-8
Abstract: 

Natural chemicals have been reported to have antibacterial effects against a variety of bacteria. The present study evaluated the antibacterial effects of commercially available grape-seed extract (GSE), pomegranate polyphenols (PP), and lab-prepared cranberry proanthocyanidins (C-PAC) against two strains of methicillin-resistant Staphylococcus aureus (MRSA). GSE, PP, and C-PAC at concentrations of 2 mg/mL, 10 mg/mL, or controls were mixed with equal volumes of overnight cultures of MRSA at ~6 log10 colony-forming units (CFU)/mL and incubated for 0, 1, 2, 8, and 24 h at 37 degrees C. Treatments were neutralized/stopped using tryptic soy broth containing 3% beef extract. Serial dilutions of the treated MRSA strains and controls were spread-plated on trypticase soy agar and incubated for 24-48 h at 37 degrees C and colonies were counted. Among the three tested agents, GSE at 1 and 5 mg/mL was found to be most effective against MRSA, resulting in a 2.9-4.0 log10 CFU/mL reduction of both strains after 2 h at 37 degrees C. PP at 1 and 5 mg/mL was found to cause 1.1-2.3 log10 CFU/mL reduction, while C-PAC at 1 mg/mL caused

Comparison of isolated cranberry (Vaccinium macrocarpon Ait.) proanthocyanidins to catechin and procyanidins A2 and B2 for use as standards in the 4-(dimethylamino)cinnamaldehyde assay

Posted: 
July 31, 2012
Authors: 
Feliciano RP, Shea MP, Shanmuganayagam D, Krueger CG, Howell AB, Reed JD
Journal: 
J Agric Food Chem 60(18):4578-85
Abstract: 

The 4-(dimethylamino)cinnamaldehyde (DMAC) assay is currently used to quantify proanthocyanidin (PAC) content in cranberry products. However, this method suffers from issues of accuracy and precision in the analysis and comparison of PAC levels across a broad range of cranberry products. Current use of procyanidin A2 as a standard leads to an underestimation of PACs content in certain cranberry products, especially those containing higher molecular weight PACs. To begin to address the issue of accuracy, a method for the production of a cranberry PAC standard, derived from an extraction of cranberry (c-PAC) press cake, was developed and evaluated. Use of the c-PAC standard to quantify PAC content in cranberry samples resulted in values that were 2.2 times higher than those determined by procyanidin A2. Increased accuracy is critical for estimating PAC content in relationship to research on authenticity, efficacy, and bioactivity, especially in designing clinical trials for determination of putative health benefits.

Cranberry proanthocyanidins act in synergy with licochalcone A to reduce Porphyromonas gingivalis growth and virulence properties, and to suppress cytokine secretion by macrophages

Posted: 
July 31, 2012
Authors: 
Feldman M, Grenier D
Journal: 
J Appl Microbiol 113(2):438-47
Abstract: 

"Aims:  Periodontitis is an inflammatory disease of polymicrobial origin that affects the tooth-supporting tissues. With the spread of antibiotic resistance among pathogenic bacteria, alternative strategies are required to better control infectious diseases such as periodontitis. The aim of our study was to investigate whether two natural compounds, A-type cranberry proanthocyanidins (AC-PACs) and licochalcone A, act in synergy against Porphyromonas gingivalis and the host inflammatory response of a macrophage model.

Methods and Results:  Using a checkerboard microtitre test, AC-PACs and licochalcone A were found to act in synergy to inhibit P. gingivalis growth and biofilm formation. Fluorescein isothiocyanate-labelled P. gingivalis adhesion to oral epithelial cells was also inhibited by a combination of the two natural compounds in a synergistic manner. Fluorometric assays showed that although AC-PACs and licochalcone A reduced both MMP-9 and P. gingivalis collagenase activities, no synergy was obtained with a combination of the compounds. Lastly, AC-PACs and licochalcone A also acted in synergy to reduce the lipopolysaccharide (LPS)-induced secretion of the pro-inflammatory mediators IL-1β, TNF-α, IL-6 and IL-8 in a macrophage model.

Conclusions:  A-type cranberry proanthocyanidins and licochalcone A, natural compounds from cranberry and licorice, respectively, act in synergy on both P. gingivalis and the host immune response, the two principal etiological factors of periodontitis.

Significance and Impact of the Study:  The combined use of AC-PACs and licochalcone A may be a potential novel therapeutic strategy for the treatment and prevention of periodontal disease."

Effects of Cranberry Extracts on Growth and Biofilm Production of Escherichia coli and Staphylococcus species

Posted: 
July 31, 2012
Authors: 
LaPlante KL, Sarkisian SA, Woodmansee S, Rowley DC, Seeram NP
Journal: 
Phytother Res doi: 10.1002/ptr.4592
Abstract: 

Biofilm producing bacteria such as Staphylococcus species and Escherichia coli are the most common cause of catheter related urinary tract infections (UTIs). The American cranberry (Vaccinium macrocarpon) is utilized widely as a prophylaxis for UTIs due to its prevention of microbial adhesion. Cranberry contains proanthocyanidins (PACs), which have been implicated as active constituents responsible for its bacterial antiadhesive properties. Despite overwhelming data supporting cranberry's beneficial effects against human pathogenic bacteria, there is limited information regarding its effects on biofilm formation. This study evaluated the effects of three proprietary PAC-standardized cranberry extracts on the inhibition of bacterial growth and biofilm production against a panel of clinically relevant pathogens: Staphylococcus epidermidis, Staphylococcus aureus, clinical methicillin-resistant S. aureus (MRSA), Staphylococcus saprophyticus and Escherichia coli. The extracts inhibited the growth of the Gram-positive bacteria (Staphylococcus spp.) but not the Gram-negative species (E. coli) with minimum inhibitory concentrations in the range 0.02–5 mg/mL. The extracts also inhibited biofilm production by the Gram-positive bacteria but did not eradicate their established biofilm. These results suggest that cranberry may have beneficial effects against the growth and biofilm producing capability of Gram-positive bacteria pathogens.

High molecular weight constituents of cranberry interfere with influenza virus neuraminidase activity

Posted: 
July 31, 2012
Authors: 
Oiknine-Djian E, Houri-Haddad Y, Weiss EI, Ofek I, Greenbaum E, Hartshorn K, Zakay-Rones Z
Journal: 
Planta Med 78(10):962-7
Abstract: 

Cranberry juice contains high molecular weight non-dialyzable material (NDM) which was found to inhibit hemagglutination induced by the influenza virus (IV) as well as to neutralize the cytotoxicity of IV in cell cultures. Because influenza virus surface glycoproteins hemagglutinin (HA) and neuraminidase (NA) are involved in viral replication and in the infectious process, we sought in the present study to examine the effect of NDM on neuraminidases which are the target of most anti-influenza drugs today. NDM inhibited the NA enzymatic activity of influenza A and B strains as well as that of Streptococcus pneumoniae. This finding is of importance considering the emergence of influenza isolates resistant to antiviral drugs, reaching 90 % in some places. The anti-NA activity of NDM, evaluated by the MUNANA method and expressed as the concentration required for 50 % inhibition (IC50), was most potent against N1 (IC50, 192 microg/mL), less active against BN and N2 (IC50, 509 microg/mL and 1128 microg/mL, respectively), and moderately active against Streptococcus pneumoniae NA (IC50, 594 microg/mL). The in vitro findings of the present study suggest that cranberry constituents may have a therapeutic potential against both A and B influenza virus infections and might also interfere with the development of secondary bacterial complications

Impact of cranberry juice on initial adhesion of the EPS producing bacterium Burkholderia cepacia

Posted: 
July 31, 2012
Authors: 
Yang X, Teng F, Zeng H, Liu Y
Journal: 
Biofouling 28(5):417-31
Abstract: 

The impact of cranberry juice was investigated with respect to the initial adhesion of three isogenic strains of the bacterium Burkholderia cepacia with different extracellular polymeric substance (EPS) producing capacities, viz. a wild-type cepacian EPS producer PC184 and its mutant strains PC184rml with reduced EPS production and PC184bceK with a deficiency in EPS production. Adhesion experiments conducted in a parallel-plate flow chamber demonstrated that, in the absence of cranberry juice, strain PC184 had a significantly higher adhesive capacity compared to the mutant strains. In the presence of cranberry juice, the adhesive capacity of the EPS-producing strain PC184 was largely reduced, while cranberry juice had little impact on the adhesion behavior of either mutant strain. Thermodynamic modeling supported the results from adhesion experiments. Surface force apparatus (SFA) and scanning electron microscope (SEM) studies demonstrated a strong association between cranberry juice components and bacterial EPS. It was concluded that cranberry juice components could impact bacterial initial adhesion by adhering to the EPS and impairing the adhesive capacity of the cells, which provides an insight into the development of novel treatment strategies to block the biofilm formation associated with bacterial infection.

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