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Miscellaneous: In-Vitro

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Protein-Bound Vaccinium Fruit Polyphenols Decrease IgE Binding to Peanut Allergens and RBL-2H3 Mast Cell Degranulation In Vitro.

Posted: 
August 15, 2017
Authors: 
Plundrich, N. J. Bansode, R. R. Foegeding, E. A. Williams, L. L. Lila, M. A.
Journal: 
Food and Function 8(4):1611-1621
Abstract: 

Peanut allergy is a worldwide health concern. In this study, the natural binding properties of plant-derived polyphenols to proteins was leveraged to produce stable protein-polyphenol complexes comprised of peanut proteins and cranberry (Vaccinium macrocarpon Ait.) or lowbush blueberry (Vaccinium angustifolium Ait.) pomace polyphenols. Protein-bound and free polyphenols were characterized and quantified by multistep extraction of polyphenols from protein-polyphenol complexes. Immunoblotting was performed with peanut-allergic plasma to determine peanut protein-specific IgE binding to unmodified peanut protein, or to peanut protein-polyphenol complexes. In an allergen model system, RBL-2H3 mast cells were exposed to peanut protein-polyphenol complexes and evaluated for their inhibitory activity on ionomycin-induced degranulation ( beta -hexosaminidase and histamine). Among the evaluated polyphenolic compounds from protein-polyphenol complex eluates, quercetin, - in aglycone or glycosidic form - was the main phytochemical identified to be covalently bound to peanut proteins. Peanut protein-bound cranberry and blueberry polyphenols significantly decreased IgE binding to peanut proteins at p<0.05 (38% and 31% decrease, respectively). Sensitized RBL-2H3 cells challenged with antigen and ionomycin in the presence of protein-cranberry and blueberry polyphenol complexes showed a significant (p<0.05) reduction in histamine and beta -hexosaminidase release (histamine: 65.5% and 65.8% decrease; beta -hexosaminidase: 60.7% and 45.4% decrease, respectively). The modification of peanut proteins with cranberry or blueberry polyphenols led to the formation of peanut protein-polyphenol complexes with significantly reduced allergenic potential. Future trials are warranted to investigate the immunomodulatory mechanisms of these protein-polyphenol complexes and the role of quercetin in their hypoallergenic potential.

Polyphenol Characterization, Anti-Oxidant, Anti-Proliferation and Anti-Tyrosinase Activity of Cranberry Pomace

Posted: 
March 6, 2017
Authors: 
Rupasinghe V, Neir SV, Parmar I
Journal: 
Functional Foods in Health and Disease 6(11):754-68
Abstract: 

Background: Cranberry pomace (CP), an underutilized by-product from juice processing, contains a wide range of biologically active compounds that can be recovered and used in a variety of applications in functional foods and nutraceuticals. Methods: In this study, analytical chemical techniques such as solvent extractions and characterization of extracts in respect with their phenolic content were performed using ultra-high performance liquid chromatography mass spectrometry (UPLC-MS) and spectrophotometry. Crude CP extract and its phenolic acids, flavonols, anthocyanins and proanthocyanidins–rich fractions were then evaluated for their anti-oxidant capacity, tyrosinase inhibitory activity, and anti-proliferation activity against hepatocellular carcinoma HepG2 cells. Results: On a dry weight basis, the different CP fractions contained seven major anthocyanins (0.1-125 mg/g), six major phenolic acids (0.8-31 mg/g), seven flavonols (1-126 mg/g) and five flavan-3-ols (0.1-12 mg/g). Fractions rich in flavonols exhibited the most potent antioxidant capacities with ferric ion reducing antioxidant power values of 1.8-1.9 mmole/g and 2, 2-diphenyl-1-picrylhydrazyl radical scavenging IC50 values of 15.1-15.2 mg/L respectively. On the other hand, fractions rich in phenolic acids and flavan-3-ol monomers demonstrated the most potent anti-tyrosinase activity (IC50=6.1-6.2 mg/L) and anti-proliferative activity (IC50=7.8-15.8 mg/L). Generally, all the fractions exhibited a dose-response relationship in the selected biological activity assays.Conclusion: This study suggests an effective utilization of CP to obtain biologically active fractions with potential to be used in functional foods and nutraceuticals designed for the prevention of chronic diseases associated with oxidative stress.

Ability of Cranberry Proanthocyanidins in Combination with a Probiotic Formulation to Inhibit in Vitro Invasion of Gut Epithelial Cells by Extra-Intestinal Pathogenic E. Coli

Posted: 
March 1, 2017
Authors: 
Polewski MA, Krueger CG, Reed JD, Leyer G
Journal: 
Journal of Functional Foods; 2016. 25:123-134
Abstract: 

Cranberries and probiotics are individually considered as functional foods. This study evaluated the potential synergy between bioactive proanthocyanidins (c-PAC) derived from cranberries and probiotics on reducing the invasiveness of extra-intestinal pathogenic Escherichia coli (ExPEC) in a cell culture model. ExPEC can be a component of the gut microbiota in healthy individuals, and reducing the invasiveness of ExPEC is a potential means to lessen the risk of subsequent urinary tract infections (UTI), the most common bacterial infections in women. c-PAC (>92% A-type) concentrations greater than 36 micro g c-PAC/mL significantly (p<0.05) reduced ExPEC invasion, and was not inhibited by the presence of probiotics. Scanning electron microscopy suggests that the mechanism by which c-PAC prevent ExPEC invasion is by cross-linking surface virulence factors. A probiotic blend also significantly reduced invasion, albeit via a different mechanism. This study demonstrated the potential benefit of combining functional A-type c-PAC components in cranberry foods with probiotics.

Comparison of A-type Proanthocyanidins in Cranberry and Peanut Skin Extracts Using Matrix Assisted Laser Desorption Ionization-Time Of Flight Mass Spectrometry

Posted: 
March 1, 2017
Authors: 
Ye L, Neilson A, Sarnoski P, Ray WK, Duncan S
Journal: 
J Mol Genet Med. 2016;10(209):1747-086
Abstract: 

Cranberry products have long been used to treat urinary tract infections. It is believed that the A-type proanthocyanidins in cranberries contribute to this function. Peanut is one of the other, few food sources that primarily contain A-type proanthocyanidins. The skin on the outside of the peanut kernels (testa), which is treated as an agriculture waste product, contains high levels of A-type proanthocyanidins. In this study, an HPLC diol column separation method and MALDI-TOF MS were used to characterize and compare the proanthocyanidin compositions of peanut skins and cranberries. MALDI-TOF MS in linear mode was able to detect a group of proanthocyanidins with DP (degree of polymerization) 10 in peanut skin extract, but was only able to detect DP 8 in cranberry extract.The reflectron mode showed clusters of clear narrow peaks at DP 7 in peanut skin extract, while the highest DP resolved for cranberry extract was only 3 in reflectron mode. This might be due to the low response intensity of the cranberry samples with the current cleanup method and the matrix. Based on the resolved peaks in reflectron mode, peanut skins and cranberries have similar proanthocyanidins composition; they contain both A-type and B-type proanthocyanidins, with the A-type being predominant. This result may inspire future studies on the comparison of biological functions between peanut skins and cranberries and further comparison of their polymeric proanthocyanidin composition.

Determination of Anthocyanins in Cherry and Cranberry by High-Performance Liquid Chromatography–Electrospray Lonization–Mass Spectrometry

Posted: 
March 1, 2017
Authors: 
Karaaslan NM, Yaman M
Journal: 
Eur Food Res Technol (2016) 242: 127
Abstract: 

Anthocyanins are a group of widespread natural phenolic compounds in vegetables and fruits. The anthocyanins have a wide range of applications due to the antioxidant, anticancer and anti-inflammatory properties. In this study, anthocyanins (delphinidin-3-o-glucoside, cyanidin-3-o-glucoside, pelargonidin-3-o-glucoside and malvidin-3-o-glucoside) in cherry and cranberry were determined using high-performance liquid chromatography–electrospray ionization–mass spectrometry (HPLC–ESI–MS). The anthocyanins were separated using gradient elution and a reserved-phase analytical column before identification by high-performance liquid chromatography–electrospray ionization–mass spectrometry. A high-performance liquid chromatography–electrospray ionization–mass spectrometry method was optimized for the determination of anthocyanins in cherry and cranberry. Furthermore, in this study, we investigated extraction conditions of fruit samples as well as determination of optimum HPLC–ESI–MS conditions. This study is novel in terms of simultaneously examining both optimization of HPLC parameters and extraction conditions. Obtained optimum conditions were used for the determination as the quantitative and qualitative analysis of anthocyanins in cherry and cranberry. The content of anthocyanins on the basis of wet weight in cherry and cranberry samples was determined for delphinidin-3-o-glucoside

Study of the Impact of Cranberry Extract on the Virulence Factors and Biofilm Formation by Enterococcus Faecalis Strains Isolated from Urinary Tract Infections

Posted: 
March 1, 2017
Authors: 
Wojnicz D, Tichaczek-Goska D, Korzekwa K, Kicia M, Hendrich AB
Journal: 
Int J Food Sci Nutr 67(8):1005-16
Abstract: 

Drinking of cranberry fruit juice and application of commercial preparations containing the cranberry extracts are recommended in the prevention and treatment of urinary tract infections (UTIs), especially in women with recurrent UTIs. Many studies focus on the activity of cranberries against uropathogenic Escherichia coli (E. coli) strains. However, the knowledge of the cranberry effect on Gram-positive Enterococcus faecalis (E. faecalis) is limited. Therefore, the aim of our study was to establish the activity of commercial concentrated cranberry extract on the growth, virulence factors and biofilm formation of E. faecalis strains isolated from urine. Minimal inhibitory concentrations (MICs) of cranberry extract were determined by the broth microdilution method. Disc diffusion method was used to determine antimicrobial susceptibility. The impact of cranberry extract on bacterial survival, hydrophobicity, synthesis of lipase, lecithinase, DNase, hemolysin, gelatinase and biofilm mass was determined. Results show that cranberry extract inhibits the growth, enzymatic activities of bacteria and limits biofilm formation. The antibacterial activities of the studied cranberry extract confirm that it could be successfully used in prevention of UTIs caused by E. faecalis.

Ultrahigh Pressure Liquid Chromatography-Atmospheric Pressure Photoionization-Tandem Mass Spectrometry for the Determination of Polyphenolic Profiles in the Characterization and Classification of Cranberry-Based Pharmaceutical preparations and natural ext

Posted: 
March 1, 2017
Authors: 
Parets L, Alechaga E, Nunez O, Saurina J, Hernandez-Cassou S, Puignou L
Journal: 
Anal Methods 8(22):4363-4378
Abstract: 

Ultrahigh pressure liquid chromatography-atmospheric pressure photoionization-tandem mass spectrometry (UHPLC-APPI-MS/MS) was applied to the analysis and authentication of fruit-based products and pharmaceutical preparations. Two sub-2 micro m C18 reversed-phase columns, Syncronis (100x2.1 mm, 1.7 micro m) and Hypersil Gold (50x2.1 mm, 1.9 micro m), were proposed under gradient elution with 0.1% formic acid aqueous solution and methanol mobile phases for the determination of 29 polyphenols, allowing us to obtain polyphenolic profiles in less than 13.5 and 23.5 min, respectively. Several atmospheric pressure ionization (API) sources (H-ESI, APCI, and APPI) were compared. For dopant-assisted APPI, four organic solvents, toluene, acetone, chlorobenzene and anisole, were evaluated as dopants. Both H-ESI and acetone-assisted APPI were selected as the best ionization sources for the analysis of targeted polyphenols. Acceptable sensitivity (LOD values down to 0.5 micro g kg-1 in the best of cases), linearity (r2 higher than 0.995) and good precision (RSD values lower than 15.1%) and trueness (relative errors lower than 10.2%) were obtained using both UHPLC-API-MS/MS methods. A simple extraction procedure, consisting of sample sonication with acetone/water/hydrochloric acid (70:29.9:0.1 v/v/v) and centrifugation, was used. The proposed UHPLC-ESI-MS/MS and UHPLC-APPI-MS/MS methods with both C18 reversed-phase columns were then applied to the analysis of 32 grape-based and cranberry-based natural products and pharmaceutical preparations. Polyphenolic profile data were then analyzed by principal component analysis (PCA) to extract information on the most significant data contributing to the classification of natural extracts according to the type of fruit.

Adjuvant effect of cranberry proanthocyanidin active fraction on antivirulent property of ciprofloxacin against Pseudomonas aeruginosa.

Posted: 
August 22, 2016
Authors: 
Vadekeetil A., Alexandar V., Chhibber S., Harjai K.
Journal: 
Microbial Pathogenesis; 2016. 90:98-103
Abstract: 

Quorum sensing inhibitors (QSIs) act as antivirulent agents since quorum sensing (QS) plays a vital role in regulating pathogenesis of Pseudomonas aeruginosa. However, application of single QSI may not be effective as pathogen is vulnerable to successful mutations. In such conditions, combination of QSIs can be exploited as there can be synergistic or adjuvant action. In the present study, we evaluated the antivirulence efficacy of combination of Vaccinium macrocarpon proanthocyanidin active fraction (PAF) and ciprofloxacin (CIP) at their sub-MICs using standard methods followed by analysis of their mode of action on QS using TLC and molecular docking. There was significant improvement in action of CIP when it was combined with PAF in reducing the QS controlled virulence factors (p<0.05), motilities and biofilm of P. aeruginosa. TLC profiles of QS signals [(Acyl homoserine lactone (AHL) and Pseudomonas quinolone signal (PQS))] indicated that CIP in combination with PAF, besides showing inhibitory action on production of AHLs, also modulated production and inactivation of PQS. Docking scores also supported the observation. We therefore hypothesize that PAF-CIP combination, having improved anti-virulence property; can be exploited as a potent drug pairing against P. aeruginosa.

Antibacterial activity of isolated phenolic compounds from cranberry (Vaccinium macrocarpon) against Escherichia coli.

Posted: 
August 22, 2016
Authors: 
Rodriguez-Perez, C. Quirantes-Pine, R. Uberos, J. Jimenez-Sanchez, C. Pena, A. Segura-Carretero, A.
Journal: 
Food and Function; 2016. 7(3):1564-1573.
Abstract: 

Phenolic compounds from a cranberry extract were isolated in order to assess their contribution to the antibacterial activity against uropathogenic strains of Escherichia coli (UPEC). With this purpose, a total of 25 fractions from a cranberry extract were isolated using semipreparative high performance liquid chromatography (HPLC) and characterized based on the results obtained by reversed-phase HPLC coupled to mass spectrometry detection. Then, the effects on UPEC surface hydrophobicity and biofilm formation of the cranberry extract as well as the purest fractions (a total of 13) were tested. As expected, the whole extract presented a powerful antibacterial activity against UPEC while the selected fractions presented a different behavior. Myricetin and quercitrin significantly decreased (p <0.05) E. coli biofilm formation compared with the control, while dihydroferulic acid glucuronide, procyanidin A dimer, quercetin glucoside, myricetin and prodelphinidin B led to a significant decrease of the surface hydrophobicity compared with the control. The results suggest that apart from proanthocyanidins, other compounds, mainly flavonoids, can act against E. coli biofilm formation and also modify UPEC surface hydrophobicity in vitro, one of the first steps of adhesion.

Cranberry derivatives enhance biofilm formation and transiently impair swarming motility of the uropathogen Proteus mirabilis HI4320.

Posted: 
August 22, 2016
Authors: 
O'May, C. Amzallag, O. Bechir, K. Tufenkji, N.
Journal: 
Can J Microbiol; 2016. 62(6):464-474.
Abstract: 

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.

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