Supplementation of egg white peptides on attenuating skin mechanical damage symptoms: a promising way to accelerate wound healing process

Large-leaf yellow tea protein derived-peptides alleviated dextran sodium sulfate-induced acute colitis and restored intestinal microbiota balance in C57BL/6 J mice

Large-leaf yellow tea (LYT)-derived peptides (TPP) are rich in amino acids required for damage repair, such as Glu, Arg, and Pro, and can be used to alleviate acute colitis. However, its effect and mechanisms against colitis remain unclear. This study utilized TPP to intervene in dextran sodium sulfate-induced acute colitis in C57BL/6 J mice. Results confirmed that TPP ameliorated acute colitis symptoms by inhibiting pro-inflammatory cytokines, restoring gut microbiota dysbiosis, particularly by increasing the abundance of beneficial bacteria Akkermansia and Lactobacillus while declining harmful microbiota Escherichia-Shigella. Besides, TPP intervention reshaped the gut microbiota phenotype by increasing the aerobic phenotype and reducing the potentially pathogenic phenotype. Levels of short-chain fatty acids, including acetic acid, propanoic acid, isobutyric acid, and butyric acid, were also enhanced in a dose-dependent manner to help restore gut microbiota equilibrium. This study supports using TPP as a viable plant protein-derived dietary resource for alleviating inflammatory bowel disease.

Advances in Research on the Activity Evaluation, Mechanism and Structure-Activity Relationships of Natural Antioxidant Peptides

Antioxidant peptides are a class of biologically active peptides with low molecular weights and stable antioxidant properties that are isolated from proteins. In this review, the progress in research on the activity evaluation, action mechanism, and structure-activity relationships of natural antioxidant peptides are summarized. The methods used to evaluate antioxidant activity are mainly classified into three categories: in vitro chemical, in vitro cellular, and in vivo animal methods. Also, the biological effects produced by these three methods are listed: the scavenging of free radicals, chelation of metal ions, inhibition of lipid peroxidation, inhibition of oxidative enzyme activities, and activation of antioxidant enzymes and non-enzymatic systems. The antioxidant effects of natural peptides primarily consist of the regulation of redox signaling pathways, which includes activation of the Nrf2 pathway and the inhibition of the NF-κB pathway. The structure-activity relationships of the antioxidant peptides are investigated, including the effects of peptide molecular weight, amino acid composition and sequence, and secondary structure on antioxidant activity. In addition, four computer-assisted methods (molecular docking, molecular dynamics simulation, quantum chemical calculations, and the determination of quantitative structure-activity relationships) for analyzing the structure-activity effects of natural peptides are summarized. Thus, this review lays a theoretical foundation for the development of new antioxidants, nutraceuticals, and cosmetics.

Peptide Supramolecular Self-Assembly: Regulatory Mechanism, Functional Properties, and Its Application in Foods

Peptide self-assembly, due to its diverse supramolecular nanostructures, excellent biocompatibility, and bright application prospects, has received wide interest from researchers in the fields of biomedicine and green life technology and the food industry. Driven by thermodynamics and regulated by dynamics, peptides spontaneously assemble into supramolecular structures with different functional properties. According to the functional properties derived from peptide self-assembly, applications and development directions in foods can be found and explored. Therefore, in this review, the regulatory mechanism is elucidated from the perspective of self-assembly thermodynamics and dynamics, and the functional properties and application progress of peptide self-assembly in foods are summarized, with a view to more adaptive application scenarios of peptide self-assembly in the food industry.

Egg White Peptides Accelerating the Wound Healing Process Through Modulating the PI3K-AKT Pathway: A Joint Analysis of Transcriptomic and Proteomic

Wound healing is a multiphase process with a complex repair mechanism; trauma-repairing products with safety and high efficiency have a great market demand. Egg white peptides (EWP) have various physiological regulatory functions and have been proven efficient in ameliorating skin damage. However, their underlying regulation mechanism has not been revealed. This study further evaluated the EWP ameliorating mechanism by conducting a full-thickness skin wound model. Results demonstrated that EWP administration significantly inhibited the expression of pro-inflammatory and shortened the inflammatory phase. Besides, EWP can accelerate the secretion of growth factors (PDGF, VEGF, and TGF-β1) in skin tissue, significantly increasing the regeneration of granulation tissue and endothelium in the proliferation phase, thereby promoting wound healing. After 400 mg/kg EWP interventions for 13 days postoperation, the wound healing rate reached 90%. The combination of transcriptomic and proteomic analyses demonstrated the ameliorating efficiency effects of EWP on wound healing. EWP mainly participates in the functional network with the PI3K-AKT signaling pathway as the core to accelerate wound healing. These findings suggest a promising EWP-based strategy for accelerating wound healing.

Potential Benefits of Egg White Proteins and Their Derived Peptides in the Regulation of the Intestinal Barrier and Gut Microbiota: A Comprehensive Review

Impaired intestinal barrier function can impede the digestion and absorption of nutrients and cause a range of metabolic disorders, which are the main causes of intestinal disease. Evidence suggests that proper dietary protein intake can prevent and alleviate intestinal diseases. Egg white protein (EWP) has received considerable attention, because of its high protein digestibility and rich amino acid composition. Furthermore, bioactive peptides may have an increased repair effect due to their high degradation efficiency in the gut. In this study, we aimed to review the effects of EWP and its bioactive peptides on intestinal structural repair. The potential modulation mechanisms by which EWP and their peptides regulate the gut microbiota and intestinal barrier can be summarized as follows: (1) restoring the structure of the intestinal barrier to its intact form, (2) enhancing the intestinal immune system and alleviating the inflammatory response and oxidative damage, and (3) increasing the relative abundance of beneficial bacteria and metabolites. Further in-depth analysis of the coregulation of multiple signaling pathways by EWP is required, and the combined effects of these multiple mechanisms requires further evaluation in experimental models. Human trials can be considered to understand new directions for development.

A Comprehensive Review of Self-Assembled Food Protein-Derived Multicomponent Peptides: From Forming Mechanism and Structural Diversity to Applications

Food protein-derived multicomponent peptides (FPDMPs) are a natural blend of numerous peptides with various bioactivities and multiple active sites that can assume several energetically favorable conformations in solutions. The remarkable structural characteristics and functional attributes of FPDMPs make them promising codelivery carriers that can coassemble with different bioactive ingredients to induce multidimensional structures, such as fibrils, nanotubes, and nanospheres, thereby producing specific health benefits. This review offers a prospective analysis of FPDMPs-based self-assembly nanostructures, focusing on the mechanism of formation of self-assembled FPDMPs, the internal and external stimuli affecting peptide self-assembly, and their potential applications. In particular, we introduce the exciting prospect of constructing functional materials through precursor template-induced self-assembly of FPDMPs, which combine the bioactivity and self-assembly capacity of peptides and could dramatically broaden the functional utility of peptide-based materials.

Construction of double network hydrogels using agarose and gallic acid with antibacterial and anti-inflammatory properties for wound healing

Gallic acid (GA) has attracted extensive attention due to its excellent health benefits. Our recent work demonstrated that GA could be self-assembled into hydrogels. However, the poor mechanical properties and rapid degradation of GA hydrogels presented challenges for further applications. In this study, agarose (AG), a water-soluble polysaccharide, was used with GA to develop a double network hydrogel (GA-AG). Physical and chemical tests demonstrated that the GA-AG hydrogel at ratio of 4:5 had the highest cross-linked structure, along with excellent porosity, good water retention and a swelling ratio of 9.72 %. In addition, the cross-linked network structure enabled the GA-AG hydrogel to have good mechanical properties and better viscosity than the pure GA hydrogel. The glass transition temperature of the GA-AG hydrogel increased from 59.49 °C to 65.54 °C, while its disintegration rate decreased from 99.07 % to 64.37 % within 48 h. In vitro tests showed that the GA-AG hydrogel had excellent antibacterial activity and biocompatibility. Meanwhile, we demonstrated that this double network hydrogel significantly reduced inflammation and accelerated wound healing in vivo. From the results of our study, we expect that this stable GA-AG double network hydrogel has potential applications in wound healing.

Recent advances of the nanocomposite hydrogel as a local drug delivery for diabetic ulcers

Diabetic ulcer is a serious complication of diabetes. Compared with that of healthy people, the skin of patients with a diabetic ulcer is more easily damaged and difficult to heal. Without early intervention, the disease will become increasingly serious, often leading to amputation or even death. Most current treatment methods cannot achieve a good wound healing effect. Numerous studies have shown that a nanocomposite hydrogel serves as an ideal drug delivery method to promote the healing of a diabetic ulcer because of its better drug loading capacity and stability. Nanocomposite hydrogels can be loaded with one or more drugs for application to chronic ulcer wounds to promote rapid wound healing. Therefore, this paper reviews the latest progress of delivery systems based on nanocomposite hydrogels in promoting diabetic ulcer healing. Through a review of the recent literature, we put forward the shortcomings and improvement strategies of nanocomposite hydrogels in the treatment of diabetic ulcers.

Mechanism of Ser-Ala-Gly-Pro-Ala-Phe treatment with a pulsed electric field to improve ethanol-induced gastric mucosa injury in mice

This paper focused on the mechanism of Ser-Ala-Gly-Pro-Ala-Phe (SAGPAF) treatment to improve gastric mucosal injury in mice. A gastric mucosa injury model induced by ethanol was established, and the superoxide dismutase (SOD) activity, malondialdehyde (MDA) content, nitric oxide (NO) content and myeloperoxidase (MPO) level were determined. We performed macroscopic and histopathological evaluation of the gastric organs. Moreover, we analyzed the mechanism of SAGPAF treatment by western blotting. Compared with the model group, the SOD activity and NO content in the medium-dose and high-dose SAGPAF groups of treated with 10 kV cm^-1 field intensity were significantly increased. The MDA content and MPO level were decreased significantly. They significantly reduced the gastric mucosal injury induced by ethanol (21.17 ± 3.51% and 13.99 ± 2.00%) and the histopathological scores (3.83 ± 0.40 and 4.33 ± 0.37) (P < 0.05). Western blotting analysis showed that SAGPAF after pulsed electric field (PEF) treatment improved gastric injury by reducing protein phosphorylation. These findings provided strong evidence that PEF-treated SAGPAF enhanced the gastric mucosal barrier function by inhibiting the activation of the mitogen-activated protein kinase (MAPK) and nuclear factor kappa-B (NF-κB) signaling pathways, reducing the ethanol-induced inflammatory response and oxidative stress.

Egg White Peptides Increased the Membrane Liquid-Ordered Phase of Giant Unilamellar Vesicles: Visualization, Localization, and Phase Regulation Mechanism

Cell membranes are heterogeneous and consist of liquid-ordered (Lo) and liquid-disordered (Ld) phases due to phase separation. Membrane regulation of egg white peptides (LCAY and QVPLW) was confirmed in our previous study. However, the underlying mechanism of phase regulation by the peptides has not been elucidated. This study aimed to explore the effect of LCAY and QVPLW on the membrane phase separation and illustrate their mechanism by giant unilamellar vesicles (GUVs). Based on phase separation visualization, LCAY and QVPLW were found to increase the Lo phase by rearranging lipids and ordering the Ld phase. LCAY and QVPLW can bind to the GUVs and localize in the amphiphilic region of the membrane. By hydrogen bonds and hydrophobic interactions, LCAY and QVPLW may play a cholesterol-like role in regulating phase separation.

In vivo and in silico studies on the mechanisms of egg white peptides in relieving acute colitis symptoms

Active peptides, as an alternative nutrition supplement, have been confirmed to have beneficial efficacy against acute colitis. Herein, egg white peptides (EWPs) were used as a nutritional supplement to relieve dextran sulfate sodium-induced acute colitis symptoms. The potential multi-component synergetic pharmacological intervention mechanism of EWPs was investigated on the basis of in silico pharmacology, bioinformatics analysis, and molecular docking. In vitro experiments demonstrated that the migration rate of HSF cells was enhanced 5.30-fold upon treatment with EWPs relative to the control group. After administration with EWPs, colitis symptoms were alleviated in a dose-dependent manner and the serum amino acid content was significantly enhanced, especially for Ala, Leu, Ser, Thr, and Met. Four peptides identified from EWPs showed a total of 52 acute colitis-related potential targets (Fit score >3.8) with network pharmacology analysis, and the targets participated in 31 signaling pathways (p < 0.001). Among these pathways, PI3K-Akt, VEGF, Ras, TNF, and MAPK signaling pathways may exert essential anti-inflammatory effects and accelerate repairing intestinal mucosa. Molecular docking showed that the majority binding energy of peptides-targets was between -10.35 kcal mol^-1 and -18.72 kcal mol^-1, and peptides mainly interacted with the core targets (Btk, Gstm1, and Rac1) by hydrogen-bonding interactions. The current study confirmed that EWPs as supplementary nutrition can alleviate acute colitis.