Nutraceutical approaches for ameliorating celiac disease
Dr. Van Buiten was the first to demonstrate the protective effects of polyphenols within the context of celiac disease. Her doctoral dissertation, completed in August 2017, examines the system from concept- characterizing protein-polyphenol interactions at the molecular level- to "consumption"- the demonstration of protein-polyphenol complex stability throughout an in vitro digestion process and their protective effects against gliadin-stimulated inflammation and intestinal permeability.
Major Findings
(1) (-)-Epigallocatechin-3-gallate, a major phenolic constituent of tea, interacts with immunodominant gliadin peptide 𝛂2-gliadin (57-89) at physiological conditions associated with digestion. The multi-phase interactions which occurs between the two dietary compounds is driven by non-specific binding, as characterized by nuclear magnetic resonance, and results in the formation of polydisperse particles. Particle formation exerts a structural change on the gliadin protein, which provides foundational support for functional changes in its immunostimulatory action.
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(2) Green tea polyphenols mitigate gliadin-mediated inflammation and permeability in vitro via multiple mechanisms including sequestration of gliadin protein (native and hydrolyzed) and prevention of hydrolysis by digestive enzymes. Native gliadin underwent in vitro digestion in the presence an absence of green tea extract; the presence of green tea extract resulted in decreased formation of low molecular weight gliadins such as those implicated in celiac disease. Pre-treatment of hydrolyzed gliadin with green tea extract resulted in decreased inflammation (as noted by decreased expression of IL-6 and IL-8) as well as reduced permeability of Caco-2 cell monolayers, a simple model for the intestinal brush border.
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