Date of Award

5-2011

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Legacy Department

Microbiology

Advisor

Jiang, Xiuping

Committee Member

Haley-Zitlin , Vivian

Committee Member

Stutzenberger , Fred

Committee Member

Tzeng , Tzuen-Rong

Abstract

Helicobacter pylori is a microaerophilic, gram-negative bacterium and among the most persistent of all human pathogens. Its presence in the gastric environment is corre-lated with diseases such as gastritis, peptic ulcers, mucosa-associated lymphoid tissue lymphoma, and gastric carcinoma. Multiple factors are believed responsible for disease progression and outcome including infecting strain(s) genetic composition, age of acqui-sition, host immune response, environment, and diet. Due to the complexity of H. pylori infection, all possible host-pathogen interactions should be considered. One important factor frequently underplayed is host dietary habits which may serve a more important role during and immediately following infection with H. pylori than previously thought.
It has been shown that people consuming diets rich in fruits and vegetables have a lower incidence of H. pylori infection and severe gastric malignancies and that this may be in part due to natural bioactive compounds acting against H. pylori. We believe that alternative, diet-based strategies may have a significant impact on attenuating this bacte-rium when used alone or in combination with current antibiotic regimes; however, natural compounds should be better studied to understand their full therapeutic potential.
Muscadine grapes, because of their high levels of polyphenolic compounds and unique chemical makeup, are believed to be a proper candidate for study since these fruits have already been shown to exert anti-H. pylori activity in vitro with effects possi-bly related to inhibition of bacterial attachment and virulence factors. The objectives of this study were to 1) identify active phenolic compounds in muscadine grape skin respon-sible for anti-H. pylori activity, 2) use DNA microarrays to study gene expression upon
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exposure to active compounds, and 3) explore the preventative potential of muscadine grape skin and identified polyphenols for ameliorating H. pylori infection and/or the H. pylori-induced inflammatory response in mice.
Our results show that muscadine grape skin and major phenolics quercetin and resveratrol exert strong anti-H. pylori activity; especially when in combination, and may have the potential to be incorporated into an effective, diet-based approach for the pre-vention and/or treatment of H. pylori infection.

Included in

Microbiology Commons

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