(P03-081-23) Investigating Structure-Function Relationships for Nutraceutical Effects of Dietary Polyphenols in Celiac Disease

Objectives: Polyphenols have been studied for their health benefits, but have also been noted as having anti-nutritional properties. The anti-nutritional properties of polyphenols have been explored for their ability to prevent celiac disease pathogenesis. A majority of this research has focused on green tea polyphenols. The objective of our study was to determine whether the protective effects of polyphenols against celiac disease are dependent on polyphenol composition. Our hypothesis was that the structure and composition of polyphenols in an extract would affect efficacy of protection against celiac disease in vitro. To test this hypothesis, we compared the protective effects of polyphenol extracts from various plant food sources, including black tea (BTP), blueberry (BP) and cranberry (CP).

Methods: BTP, BP and CP were characterized for total polyphenols, total anthocyanins and total proanthocyanidins. Protein-polyphenol complex formation between gluten and each extract was measured using UV-Vis. The influence of binding on protein structure was characterized using circular dichroism. The ability of each extract to prevent gluten digestion was evaluated by adding extracts to in vitro digestions of gluten and analyzing the resulting digesta via SDS-PAGE, and by measuring pepsin and trypsin inhibition. The ability of extracts to protect against celiac disease-associated inflammation was measured in small intestinal epithelial cells and celiac PBMCs.

Results: The extracts used in this study each exhibited unique polyphenolic profiles. BTP demonstrated the greatest protein binding capacity followed by CP, then BP. BTP was also the only extract to disrupt digestion of gluten protein. We also observed differential effects of each extract in the prevention of intestinal permeability and inflammation in vitro. These findings suggest that polyphenol structure influences functionality in vitro.

Conclusions: The development of complementary and alternative therapies for celiac disease is critical, as there is no known cure beyond the gluten-free diet. Findings from this study support further investigation of polyphenols as an accessible therapy for celiac disease, and underscore the importance of understanding the unique functional attributes of polyphenols in health applications.

Funding Sources: This research was funded by Colorado State University.