Ultrasound Improved the Non-Covalent Interaction of β-Lactoglobulin with Luteolin: Regulating Human Intestinal Microbiota and Conformational Epitopes Reduced Allergy Risks

Abstract

The present study aims to investigate the effects of ultrasound on the non-covalent interaction of β-lactoglobulin (β-LG) and luteolin (LUT) and to investigate the relationship between allergenicity and human intestinal microbiota. After treatment, the conformational structures of β-LG were changed, which reflected by the decrease in α-helix content, intrinsic fluorescence intensity and surface hydrophobicity, whereas the β-sheet content increased. Molecular docking studies revealed the non-covalent interaction of β-LG and LUT by hydrogen bond, van der Walls bond and hydrophobic bond. β-LG-LUT complex treated by ultrasound has a lower IgG/IgE binding ability and inhibits the allergic reaction of KU812 cells, depending on the changes in the conformational epitopes of β-LG. Meanwhile, the β-LG-LUT complex affected the composition of human intestinal microbiota, such as the relative abundance of Bifidobacterium and Prevotella. Therefore, ultrasound improved the non-covalent interaction of β-LG with LUT, and the reduction in allergenicity of β-LG depends on conformational epitopes and human intestinal microbiota changes.

Exploring the potential mechanisms of Danshen against COVID-19 via network pharmacology analysis and molecular docking

“…Specifically, our investigation identified 59 candidate components of Danshen that may be effective in treating COVID-19, with Luteolin emerging as the most promising compound due to it’s the largest number of targets interactions in target prediction and network construction. Luteolin is a naturally occurring flavonoid found in various plants 50 , and it possesses various pharmacological activities, including anti-inflammatory 51 , anti-tumor 52 , and anti-allergy effects 53 . Existing studies have demonstrated that Luteolin can attenuate LPS-induced myocardial injury by activating AMPK-mediated autophagy 54 , suppress THP-1 macrophage pyroptosis by inhibiting ROS production through Nrf2 activation and NF-κB inactivation 55 , and mitigate breast cancer hallmarks by downregulating Nrf2-mediated gene expressions 56 .…”

In Vitro Effect of Flavonoids on Basophils Degranulation and Intestinal Epithelial Barrier Damage Induced by ω-5 Gliadin-Derived Peptide

“…In addition, we only observed the effect of three different subclass flavonoids on inhibiting degranulation and enhancing intestinal barrier, but did not investigate the structure-activity relationship in the study. Previous studies demonstrated that flavonoids, including the tested flavonoids naringenin [ 57 ] and luteolin [ 58 ] in the study, can inhibit the antigenicity of milk allergen β-lactoglobulin through non-covalent interactions, and the structure of flavonoids and antigenicity reduction of β-lactoglobulin are correlated [ 57 ]. Thus, it can be seen that the flavonoid-gliadin peptide P4 interaction maybe be responsible for the protective effect against allergenicity.…”

Effect of the Combined Ultrasound with Other Technologies on Food Allergenicity: Ultrasound before, under, and after Other Technologies

“…ELISA and KU812 cells demonstrated that there was a higher reduction of IgG/IgE binding ability, IL-6 and histamine levels in noncovalent βlactoglobulin-luteolin complex under ultrasound 300 W for 15 min than the simple mixture of lactoglobulin and luteolin, compared to ultrasonicated β-lactoglobulin and untreated samples. 86 It was also observed that the noncovalent βlactoglobulin-luteolin complex under ultrasound exhibited more structural changes (e.g., the highest decrease of α-helix and intrinsic fluorescence intensity) and remission degree of human intestinal microbiota than other treated samples. 86 Similar results were shown in the study of Wang et al, 74 who found that the noncovalent β-lactoglobulin-luteolin complex under ultrasound exhibited more decrease of intrinsic fluorescence intensity and β-sheet and more increase of ultraviolet absorption intensity than the simple mixture of lactoglobulin and luteolin, and ultrasonicated β-lactoglobulin, compared to the untreated samples.…”

“…86 It was also observed that the noncovalent βlactoglobulin-luteolin complex under ultrasound exhibited more structural changes (e.g., the highest decrease of α-helix and intrinsic fluorescence intensity) and remission degree of human intestinal microbiota than other treated samples. 86 Similar results were shown in the study of Wang et al, 74 who found that the noncovalent β-lactoglobulin-luteolin complex under ultrasound exhibited more decrease of intrinsic fluorescence intensity and β-sheet and more increase of ultraviolet absorption intensity than the simple mixture of lactoglobulin and luteolin, and ultrasonicated β-lactoglobulin, compared to the untreated samples. As a result, there were a lower HIS, IL-4 and IL-6 levels in the noncovalent βlactoglobulin-luteolin complex based on the KU812 cells experiment.…”