Article

Inhibition of Helicobacter pylori and Associated Urease by Oregano and Cranberry Phytochemical Synergies

Department of Food Science, Chenoweth Laboratory, University of Massachusetts, Amherst, MA 01003, USA.
Applied and Environmental Microbiology (Impact Factor: 3.67). 01/2006; 71(12):8558-64. DOI: 10.1128/AEM.71.12.8558-8564.2005
Source: PubMed

ABSTRACT

Ulcer-associated dyspepsia is caused by infection with Helicobacter pylori. H. pylori is linked to a majority of peptic ulcers. Antibiotic treatment does not always inhibit or kill H. pylori with potential for antibiotic resistance. The objective of this study was to determine the potential for using phenolic phytochemical
extracts to inhibit H. pylori in a laboratory medium. Our approach involved the development of a specific phenolic profile with optimization of different
ratios of extract mixtures from oregano and cranberry. Subsequently, antimicrobial activity and antimicrobial-linked urease
inhibition ability were evaluated. The results indicated that the antimicrobial activity was greater in extract mixtures than
in individual extracts of each species. The results also indicate that the synergistic contribution of oregano and cranberry
phenolics may be more important for inhibition than any species-specific phenolic concentration. Further, based on plate assay,
the likely mode of action may be through urease inhibition and disruption of energy production by inhibition of proline dehydrogenase
at the plasma membrane.

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    • "Phenolic compounds are able to damage the cell membrane and thus increase permeability (Hendry and others 2009). They also may interfere with electron transport chain along the bacterial membrane and inhibit dehydrogenase-linked proton efflux such as proline dehydrogenase (Lin and others 2005). These data may "

    Full-text · Dataset · Mar 2015
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    • "pylori activity of the essential oil or different extracts of Oregano species [8,20,24]. Also, some reports suggested synergistic effects against H. pylori in vitro of phenolics from oregano and cranberry water soluble extracts (0.1 mg of phenolics/ disc) through urease inhibition and disruption of the energy production by inhibition of proline dehydrogenase at the plasma membrane [25]. O. basilicum is also an aromatic plant rich in essential oil and phenolic compounds (flavonoids, phenolic acids) with known antimicrobial activity. "

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    • "saprophyticus (protein Q4A0J5, the alpha subunit encoded by SSP0263 or ureC; protein Q4A0J4, the beta subunit encoded by SSP0254 or ureB; and protein Q4A0J3, the gamma subunit encoded by SSP0265 or ureA) indicate that these proteins do not contain cysteine residues (Sch€ afer and Kaltwasser 1994; Kuroda et al. 2005). Extracts of various plants including green tea and cranberries often have been used to treat gastritis or urinary tract infections because they contain urease inhibitors (Matsubara et al. 2003; Lin et al. 2005). Urease activity from Staph. "
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    ABSTRACT: Unlabelled: Urease is a virulence factor for the Gram-positive urinary tract pathogen Staphylococcus saprophyticus. The susceptibility of this enzyme to chemical inhibition was determined using soluble extracts of Staph. saprophyticus strain ATCC 15305. Acetohydroxamic acid (Ki = 8.2 μg ml(-1) = 0.106 mmol l(-1) ) and DL-phenylalanine hydroxamic acid (Ki = 21 μg ml(-1) = 0.116 mmol l(-1) ) inhibited urease activity competitively. The phosphorodiamidate fluorofamide also caused competitive inhibition (Ki = 0.12 μg ml(-1) = 0.553 μmol l(-1) = 0.000553 mmol l(-1) ), but the imidazole omeprazole had no effect. Two flavonoids found in green tea extract [(+)-catechin hydrate (Ki = 357 μg ml(-1) = 1.23 mmol l(-1) ) and (-)-epigallocatechin gallate (Ki = 210 μg ml(-1) = 0.460 mmol l(-1) )] gave mixed inhibition. Acetohydroxamic acid, DL-phenylalanine hydroxamic acid, fluorofamide, (+)-catechin hydrate and (-)-epigallocatechin gallate also inhibited urease activity in whole cells of strains ATCC 15305, ATCC 35552 and ATCC 49907 grown in a rich medium or an artificial urine medium. Addition of acetohydroxamic acid or fluorofamide to cultures of Staph. saprophyticus in an artificial urine medium delayed the increase in pH that normally occurs during growth. These results suggest that urease inhibitors may be useful for treating urinary tract infections caused by Staph. saprophyticus. Significance and impact of the study: The enzyme urease is a virulence factor for the Gram-positive urinary tract pathogen Staphylococcus saprophyticus. We have shown that urease activity in cell-free extracts and whole bacterial cells is susceptible to inhibition by hydroxamates, phosphorodiamidates and flavonoids, but not by imidazoles. Acetohydroxamic acid and fluorofamide in particular can temporarily delay the increase in pH that occurs when Staph. saprophyticus is grown in an artificial urine medium. These results suggest that urease inhibitors may be useful as chemotherapeutic agents for the treatment of urinary tract infections caused by this micro-organism.
    Full-text · Article · Sep 2013 · Letters in Applied Microbiology
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