Nathalie Plundrich

Novel strategy to create hypoallergenic peanut protein-polyphenol edible matrices for oral immunotherapy.

Peanut allergy is an IgE-mediated hypersensitivity. Upon peanut consumption by an allergic individual, epitopes on peanut proteins bind and cross-link peanut-specific IgE on mast cell and basophil surfaces triggering the cells to release inflammatory mediators responsible for allergic reactions. Polyphenolic phytochemicals have high affinity to bind proteins and form soluble and insoluble complexes with unique functionality. This study investigated the allergenicity of polyphenol-fortified peanut matrices prepared by complexing various polyphenol-rich plant juices and extracts with peanut flour. Polyphenol-fortified peanut matrices reduced IgE binding to one or more peanut allergens (Ara h 1, Ara h 2, Ara h 3, and Ara h 6). Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) suggested changes in secondary protein structure. Peanut protein-cranberry polyphenol fortified matrices triggered significantly less basophil degranulation than unmodified flour in an ex vivo assay using human blood and less mast cell degranulation when used to orally challenge peanut-allergic mice. Polyphenol fortification of peanut flour resulted in a hypoallergenic matrix with reduced IgE binding and degranulation capacity, likely due to changes in protein secondary structure or masking of epitopes, suggesting potential applications for oral immunotherapy.

Bioactive polyphenols from muscadine grape and blackcurrant stably concentrated onto protein-rich matrices for topical applications

Natural botanical agents that are antimicrobial, or that modulate skin hyperpigmentation via tyrosinase inhibition, are increasingly sought in the cosmetic industry.

Compounds leached from quinoa seeds inhibit matrix metalloproteinase activity and intracellular reactive oxygen species

Quinoa (Chenopodium quinoa Willd.) is a seed crop rich in bioactive compounds including phytoecdysones (especially 20‐hydroxyecdysone, 20HE), polyphenols, proteins and essential fatty acids. We previously reported a method to leach and concentrate quinoa bioactives into a complex phytochemical mixture termed quinoa leachate (QL). Here, we aimed to determine the effect of QL and its chemically distinct fractions on five biochemical endpoints relevant to skin care applications: (i) cell viability, (ii) matrix metalloproteinase (MMP) mRNA expression, (iii) MMP enzymatic activity, (iv) tyrosinase enzymatic activity and (v) intracellular reactive oxygen species (ROS) production.

Peanut flour aggregation with polyphenolic extracts derived from peanut skin inhibits IgE binding capacity and attenuates RBL-2H3 cells degranulation via MAPK signaling pathway

This study investigates the anti-allergic properties of peanut skin polyphenols (PSP)-enriched peanut (PN) protein aggregates. PSP was blended with PN flour at concentrations of 5, 10, 15, 30, and 40% (w/w). Rat basophil leukemia cells (RBL-2H3) were sensitized with either anti-DNP-IgE or PN-allergic plasma followed by co-exposure to unmodified PN flour (control) or PSP-PN protein aggregates and Ca2+ ionophore, ionomycin. Immunoblotting and staining were performed to measure the IgE binding capacity of PSP-PN aggregates. Results showed that 30% PSP-PN aggregate significantly reduced β-hexosaminidase and histamine levels by 54.2% and 49.2%, respectively compared with control. Immunoblotting results revealed 40% PSP-PN aggregates significantly decreased IgE binding by 19%. The phosphorylation of p44/42 MAPK was significantly reduced while phosphorylation of p38 MAPK and SAPK/JNK increased upon PSP-PN protein aggregate exposure to the cells. Our results show that aggregation of PSP to PN proteins reduces allergic response by inhibiting Ca2+-induced MAPK-dependent cell degranulation.

Protein-bound polyphenols create “ghost” band artifacts during chemiluminescence-based antigen detection

Antigen detection during Western blotting commonly utilizes a horseradish peroxidase-coupled secondary antibody and enhanced chemiluminescent substrate. We utilized this technique to examine the impact of green tea-derived polyphenols on the binding of egg white protein-specific IgE antibodies from allergic human plasma to their cognate antigens. Our experiments unexpectedly showed that green tea-derived polyphenols, when stably complexed with egg white proteins, caused “ghost” band formation in the presence of horseradish peroxide. This study suggests that caution should be taken when evaluating polyphenol-bound proteins by enhanced chemiluminescence Western blotting using horseradish peroxidase and demonstrates that protein-bound polyphenols can be a source of “ghost” band artifacts on Western blots.