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

Casein-quaternary chitosan complexes induced the soft assembly of egg white peptide and curcumin for ulcerative colitis alleviation

Soft assembly of peptide and curcumin (Cur) molecules enables functional integration by finding dynamic equilibrium states through non-covalent interactions. Herein, we developed two soft assembly systems, curcumin-egg white peptides (Cur-EWP) aggregations (AGs) and Cur-EWP-casein-quaternary chitosan (Cur-EWP-CA-QC) nanoparticles (NPs) to comparatively investigate their therapeutic effects on ulcerative colitis in mice and elucidate their underlying mechanism. Results revealed that Cur-EWP AGs, despite gastrointestinal tract instability, exhibited a propensity for swift accumulation within the colorectal region, enriching mucus-associated and short-chain fatty acid (SCAF)-producing bacteria, restoring the intestinal barrier damage. Whereas, Cur-EWP-CA-QC NPs, benefiting from their remarkable stability and exceptional mucosal adsorption properties, not only enhanced permeability of Cur and EWP in the small intestine to activate the immune response and boost tight junction protein expression but also, in their unabsorbed state, regulated the intestinal flora, exerting potent anti-inflammatory activity. Soft assembly of peptides and hydrophobic nutraceuticals could synergize biological activities to modulate chronic diseases.

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.

Protective effects and potential mechanisms of fermented egg-milk peptides on the damaged intestinal barrier

Introduction

Fermented egg-milk peptides (FEMPs) could enhance the colon-intestinal barrier and upgrade the expression of zonula occludens-1 and mucin 2. Besides, the underlying biological mechanism and the targets FEMPs could regulate were analyzed in our study.

Methods

Herein, the immunofluorescence technique and western blot were utilized to evaluate the repair of the intestinal barrier. Network pharmacology analysis and bioinformatics methods were performed to investigate the targets and pathways affected by FEMPs.

Results and discussion

Animal experiments showed that FEMPs could restore intestinal damage and enhance the expression of two key proteins. The pharmacological results revealed that FEMPs could regulate targets related to kinase activity, such as AKT, CASP, RAF, and GSK. The above targets could interact with each other. GO analysis indicated that the targets regulated by FEMPs could participate in the kinase activity of the metabolic process. KEGG enrichment revealed that the core targets were enriched in pathways related to cell apoptosis and other important procedures. Molecular docking demonstrated that FEMPs could bind to the key target AKT via hydrogen bond interactions. Our study combined the experiment in vivo with the method in silico and investigated the interaction between peptides and targets in a pattern of multi-targets and multi-pathways, which offered a new perspective on the functional validation and potential application of bioactive peptides.

Computer-Aided Screening and Revealing Action Mechanism of Food-Derived Tripeptides Intervention in Acute Colitis

Food-derived tripeptides can relieve colitis symptoms; however, their alleviation mode has not been systematically evaluated as an alternative nutritional compound. This study aimed to reveal the potential mechanism of 8000 food-derived tripeptides against acute colitis using a computer-aided screening strategy. Forty-one potential hub targets related to colitis with a Fit score > 4.0 were screened to construct the protein-protein and protein-tripeptide network based on the PharmMapper database and STRING software (Ver. 11.5). In addition, 30 significant KEGG signaling pathways with p-values < 0.001 that the 41 hub targets mainly participated in were identified using DAVID software (Ver. 6.8), including inflammatory, immunomodulatory, and cell proliferation and differentiation-related signaling pathways, particularly in the Ras- and PI3K-Akt signaling pathways. Furthermore, molecular docking was performed using the Autodock against majorly targeted proteins (AKT1, EGFR, and MMP9) with the selected 52 tripeptides. The interaction model between tripeptides and targets was mainly hydrogen-bonding and hydrophobic interactions, and most of the binding energy of the tripeptide target was less than −7.13 kcal/mol. This work can provide valuable insight for exploring food-derived tripeptide mechanisms and therapeutic indications.

Ovalbumin and its Maillard reaction products ameliorate dextran sulfate sodium-induced colitis by mitigating the imbalance of gut microbiota and metabolites

The Maillard reaction reduces the gastrointestinal digestibility of ovalbumin (OVA) in vitro. However, the regulatory effects of OVA and its Maillard reaction products (MRPs) on gut microbiota disorders remain unknown. In this study, the influence of OVA and its MRPs on the modulation of gut microbiota in mice with dextran sulfate sodium (DSS)-induced colitis was investigated. The results revealed that OVA and its MRPs intake could alleviate the symptoms of colitis and improve the richness and diversity of the gut microbiota. Moreover, the results revealed that the Maillard reaction would block the release of lysine and essential amino acids in vivo, but they variously regulated the gut microbiota and the levels of short-chain fatty acids (SCFAs) due to their indigestible properties. These findings provide a basic theory for the rational utilization of OVA and its MRPs as nutraceutical food ingredients in regulating the gut microbiota for maintaining intestinal health.