title: Protein-bound Vaccinium fruit polyphenols decrease IgE binding to peanut allergens and RBL-2H3 mast cell degranulation in vitro.
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 (β-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 β-hexosaminidase release (histamine: 65.5% and 65.8% decrease; β-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.
authors.affiliation: Plants for Human Health Institute, Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, North Carolina Research Campus, 600 Laureate Way, Kannapolis, NC 28081, USA. mlila@ncsu.edu.
authors.forename: Nathalie J
authors.initials: NJ
authors.lastname: Plundrich
authors.forename: Rishipal R
authors.initials: RR
authors.lastname: Bansode
authors.forename: E Allen
authors.initials: EA
authors.lastname: Foegeding
authors.forename: Leonard L
authors.initials: LL
authors.lastname: Williams
authors.forename: Mary Ann
authors.initials: MA
authors.lastname: Lila
mesh_terms: D000485:Allergens / Q000276:immunology*; D010367:Arachis / Q000276:immunology*; D015550:Cell Degranulation / Q000187:drug effects*; D005638:Fruit / Q000737:chemistry; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology*; D008407:Mast Cells / Q000187:drug effects* / Q000276:immunology / Q000502:physiology; D021183:Peanut Hypersensitivity / Q000188:drug therapy* / Q000276:immunology; D010936:Plant Extracts / Q000494:pharmacology*; D010940:Plant Proteins / Q000276:immunology*; D059808:Polyphenols / Q000494:pharmacology*; D029796:Vaccinium / Q000737:chemistry*
chemical_list: D000485:Allergens; D010936:Plant Extracts; D010940:Plant Proteins; D059808:Polyphenols; D007073:Immunoglobulin E