Oral administration of hen egg white ovotransferrin attenuates the development of colitis induced by dextran sodium sulfate in mice

Lactiplantibacillus plantarum and Saccharomyces cerevisiae-Fermented Coconut Water Alleviates Dextran Sodium Sulfate-Induced Enteritis in Wenchang Chicken: A Gut Microbiota and Metabolomic Approach

In order to investigate the potential mechanisms of probiotic-fermented coconut water in treating enteritis, this study conducted a comprehensive analysis of the effects of probiotic intervention on the recovery from Dextran Sodium Sulfate-induced acute enteritis in Wenchang chicks. The analysis encompassed the assessment of growth performance, serum indicators, intestinal tissue structure, and metagenomic and metabolomic profiles of cecal contents in 60 Wenchang chicks subjected to intervention. This approach aimed to elucidate the impact of probiotic intervention on the recovery process from acute enteritis at both the genetic and metabolic levels in the avian model. The results revealed that intervention with Saccharomyces cerevisiae Y301 improved the growth rate of chicks. and intervention with Lactiplantibacillus plantarum MS2c regulated the glycerophospholipid metabolism pathway and reshaped the gut microbiota structure in modeling chicks with acute enteritis, reducing the abundance of potentially pathogenic bacteria from the Alistipes and increasing the abundance of potentially beneficial species from the Christensenellaceae. This intervention resulted in the production of specific gut metabolites, including Gentamicin C and polymyxin B2, recognized for their therapeutic effects on acute enteritis. The combined intervention of S. cerevisiae Y301 and L. plantarum MS2c not only enhanced growth performance but also mitigated intestinal wall damage and increased the abundance of gut metabolites such as gentamicin C and polymyxin B2, thereby mitigating symptoms of enteritis. Furthermore, this combined intervention reduced the levels of serum immune markers, including IL-10, IL-6, TNF-α, IFN-γ, and D-lactic acid, thus mitigating intestinal epithelial cell damage and promoting acute enteritis recovery. This study provides crucial insights into the mechanisms of action of probiotics and probiotic-fermented coconut water in acute enteritis recovery, offering new perspectives for sustainable farming practices for Wenchang chicken.

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.

Consumption of Different Egg-Based Diets Alters Clinical Metabolic and Hematological Parameters in Young, Healthy Men and Women

Eggs-particularly egg yolks-are a rich source of bioactive nutrients and dietary compounds that influence metabolic health, lipid metabolism, immune function, and hematopoiesis. We investigated the effects of consuming an egg-free diet, three egg whites per day, and three whole eggs per day for 4 weeks on comprehensive clinical metabolic, immune, and hematologic profiles in young, healthy adults (18-35 y, BMI < 30 kg/m2 or <30% body fat for men and <40% body fat for women, n = 26) in a 16-week randomized, crossover intervention trial. We observed that average daily macro- and micronutrient intake significantly differed across egg diet periods, including greater intake of choline during the whole egg diet period, which corresponded to increased serum choline and betaine without altering trimethylamine N-oxide. Egg white and whole egg intake increased serum isoleucine while whole egg intake reduced serum glycine-markers of increased and decreased risk of insulin resistance, respectively-without altering other markers of glucose sensitivity or inflammation. Whole egg intake increased a subset of large HDL particles (H6P, 10.8 nm) and decreased the total cholesterol:HDL-cholesterol ratio and % monocytes in female participants using combined oral contraceptive (COC) medication (n = 11) as compared to female non-users (n = 10). Whole egg intake further increased blood hematocrit whereas egg white and whole egg intake reduced blood platelet counts. Changes in clinical immune cell counts between egg white and whole egg diet periods were negatively correlated with several HDL parameters yet positively correlated with measures of triglyceride-rich lipoproteins and insulin sensitivity. Overall, the intake of whole eggs led to greater overall improvements in micronutrient diet quality, choline status, and HDL and hematologic profiles while minimally-yet potentially less adversely-affecting markers of insulin resistance as compared to egg whites.

Ovotransferrin Inhibits TNF-α Induced Inflammatory Response in Gastric Epithelial Cells via MAPK and NF-κB Pathway

Ovotransferrin (OVT) has been confirmed to have anti-inflammatory activity. However, its effect and mechanism on gastric inflammation are unclear. In this study, the effect and mechanism of the OVT on the tumor necrosis factor-α (TNF-α) induced inflammatory response in gastric epithelial cells (GES-1) were investigated. The enzyme linked immunosorbent assay (ELISA) was used to determine the levels of inflammation cytokines, followed by RNA sequencing to explore the potential pathways of its anti-inflammatory effect, and then it was validated by Western blotting and pathways inhibitors. Results showed that the OVT at concentrations of 50-400 μg/mL displayed nontoxicity against GES-1 cells. Additionally, 100 μg/mL of OVT obviously reduced the secretion of interleukin (IL)-8, IL-6, and TNF-α by 63.02% (630.09/1703.98), 35.53% (935.81/1451.43), and 36.19% (964.60/1511.63), respectively. The results of RNA sequencing exhibited that the OVT significantly influences the activation of mitogen-activated protein kinase (MAPK) and the nuclear factor kappa-light-chain enhancer of activated B cell (NF-κB) pathways, which was verified by the levels of p-IKK, p-IκB, p-P65, p-ERK, p-JNK, and p-P38 protein. IL-8 contents released by GES-1 cells after incubation with inhibitors of NF-κB and MAPK pathways further confirmed that OVT hindered activation of these two pathways. Collectively, these results suggested that OVT was a natural protein with the potential to treat gastric inflammation.

Effects of citric acid crosslinking on the structure and properties of ovotransferrin and chitosan composite films

In this study, ovotransferrin/chitosan (OVT/CS) composite films cross-linked by citric acid (CA) were prepared and the effects of CA cross-linking on the structure and physicochemical properties of the composite films were investigated. The cross-linking degree measured by 2,4,6-trinitrobenzenesulfonic acid (TNBS) method confirmed that CA was cross-linked with the matrix, and Fourier transform infrared spectroscopy confirmed that more hydrogen bonds and electrostatic interactions were formed between CA and the matrix. Differential scanning calorimetry, X-ray diffraction and Scanning electron microscope images revealed the compatibility between substances. The synergistic inhibition between the matrix results in a significantly higher antibacterial activity of the composite film than the pure film. Compared with uncross-linked films, the mechanical properties, barrier properties and water resistance of the cross-linked films were significantly improved. When the concentration of CA was 5 wt% (W/W, on a dry basis of the weight of OVT and CS), the most significant improvement in film performance was obtained. The tensile strength of the film increased from 32.05 MPa without cross-linking to 61.99 MPa and the swelling degree decreased from 51.5 % to 24.23 %. The observed phenomena suggest that cross-linking OVT and CS with CA can obtain functional edible films with improved properties.

Providing New Insights on the Molecular Properties and Thermal Stability of Ovotransferrin and Lactoferrin

Ovotransferrin (OVT) is a multi-functional protein showing over 50% homology with Bovine lactoferrin (BLF) and human lactoferrin (HLF), which have the potential to be a substitute for lactoferrin (LF) due to the limited production of LF. To explore the substitutability of OVT, the molecular properties and thermal stability of OVT, BLF and HLF were characterized because these properties will affect the processing quality and biological activities of protein products when exposed to different processing conditions (e.g., temperature, pH, ion strength). The results showed that although obviously different isoelectric point (5.31, 9.12 and 8.75 for OVT, BLF and HLF, respectively), particle size distribution and hydrophobicity were found, they exhibited good dispersity because of high potential value. They showed an endothermic peak at 80.64 °C, 65.71 °C and 90.01 °C, respectively, and the denaturation temperature varied at different pH and ionic strength. OVT and BLF were more susceptible to heating at pH 5.0 as reflected by the decline of denaturation temperature (21.78 °C shift for OVT and 5.81 °C shift for BLF), while HLF could remain stable. Compared with BLF, OVT showed higher secondary structure stability at pH 7.0 and 9.0 with heating. For example, the α-helix content of OVT changed from 20.35% to 15.4% at pH 7.0 after heating, while that of BLF changed from 20.05% to 6.65%. The increase on fluorescence intensity and redshifts on the maximum wavelength after heating indicated the changes of tertiary structure of them. The turbidity measurements showed that the thermal aggregation degree of OVT was lower than BLF and HLF at pH 7.0 (30.98%, 59.53% and 35.66%, respectively) and pH 9.0 (4.83%, 12.80% and 39.87%, respectively). This work demonstrated the similar molecular properties and comparable thermal stability of OVT to BLF and HLF, which can offer a useful reference for the substitute of LF by OVT.

Structural characterization of peach gum polysaccharide and its effects on the regulation of DSS-induced acute colitis

The structure and the effect of polysaccharide from peach gum (DPG2) on ameliorating DSS-induced acute colitis in mice were investigated in the present study. The results showed that DPG2 was identified as an AG II arabinogalactan with the backbone of β-D-(1 → 6)-galactan, which consisted of mannose, glucuronic acid, galactose, xylose and arabinose with a molar ratio of 4.64:1.02:2.61:39.82:3.89:48.02. Moreover, DPG2 behaved as a flexible chain conformation with a coil-like structure with a molecular weight (M_w) of 5.21 × 10⁵ g/mol. Furthermore, the worm-like chain model parameters for DPG2 were estimated as follows: M_L = 379 nm^-1, q = 0.74 nm and d = 0.82 nm. The results of the animal assay showed that the intake of DPG2 not only effectively improved the phenotypes of DSS-induced colitis in mice, but also significantly improved the oxidative stress status of mice, such as regulating NO content and T-SOD and MPO levels and repairing oxidative damage to the colonic mucosa. Moreover, DPG2 improved the inflammation of DSS-induced colitis in mice by inhibiting the secretion of the proinflammatory cytokines TNF-α, IFN-γ, IL-1β, IL-6 and IL-17. Therefore, these results suggested that peach gum polysaccharide showed protective effects against colitis, and has great potential for the application of functional components in the food industry.

Peptides and protein hydrolysates exhibiting anti-inflammatory activity: sources, structural features and modulation mechanisms

Inflammation is the response of the immune system to harmful stimuli such as tissue injury, infection or toxic chemicals, which has the aim of eliminating irritants or pathogenic microorganisms and enhancing tissue repair. Uncontrolled long-lasting acute inflammation can gradually progress to chronic, causing a variety of chronic inflammatory diseases that are usually treated with anti-inflammatory drugs, but most of them are inadequate to control chronic responses and are also associated with adverse side effects. Thus, many efforts are being directed to develop alternative and more selective anti-inflammatory therapies from natural products. One main field of interest is the obtaining of bioactive peptides exhibiting anti-inflammatory activity from sustainable protein sources like edible insects or agroindustry and fishing by-products. This work highlighted the structure-activity relationship of anti-inflammatory peptides. Small peptides with molecular weight under 1 kDa and amino acid chain length between 2 to 20 residues are generally the most active because of the higher probability to be absorbed in the intestine and penetrate into cells when compared with the larger size peptides. The presence of hydrophobic (Val, Ile, Pro) and positively charged (His, Arg, Lys) amino acids is another common occurrence for anti-inflammatory peptides. Interestingly, a high percentage (77%) of these bioactive peptides can be found in alternative sustainable protein sources such as Tenebrio molitor or sunflower, apart from its original protein source. However, not all of these peptides with anti-inflammatory potential in vitro achieve good scores by the in silico bioactivity predictors studied. Therefore, it is essential to implement current bioinformatics tools, in order to complement in vitro experiments with prior prediction of potential bioactive peptides.

The mitigative effect of ovotransferrin-derived peptide IQW on DSS-induced colitis via alleviating intestinal injury and reprogramming intestinal microbes

Inflammatory bowel disease (IBD) is a chronic disease with multiple complications during its development, and it is difficult to cure. The aim of this study was to evaluate the alleviating effect of different concentrations of the bioactive peptide IQW (Ile-Gln-Trp) on dextran sodium sulfate (DSS)-induced colitis in mice. For this study, we randomly divided 56 ICR mice into seven groups: the (I) control (CON), (II) dextran sodium sulfate treatment (2.5% DSS), (III) IQW-DSS (20 μg/ml) treatment, (IV) IQW-DSS (40 μg/ml) treatment, (V) IQW-DSS (60 μg/ml) treatment, (VI) IQW-DSS (80 μg/ml) treatment, and (VII) IQW-DSS (100 μg/ml) groups. The results showed that IQW at 60 μg/ml alleviated body weight loss, improved the liver index (p < 0.05), and improved histomorphological and pathological changes in the colon compared to the DSS-treated group. IQW at 60 μg/ml and IQW at 80 μg/ml modified intestinal microbial disorders. In addition, IQW at 60 μg/ml significantly increased butyric acid levels and decreased valeric acid levels, while IQW at 80 μg/ml significantly increased isobutyric acid and isovaleric acid levels. Hence, IQW at a concentration of 60 μg/ml alleviates DSS-induced colitis by enhancing the body's anti-inflammatory ability and regulating intestinal flora and metabolic changes. In the above context, IQW at 60 μg/ml could be a potential candidate for IBD prevention and treatment.

Nutrition and Supplementation in Ulcerative Colitis

Ulcerative colitis (UC) belongs to the group of inflammatory bowel diseases (IBD). UC is an incurable, diffuse, and chronic inflammatory process of the colonic mucosa with alternating periods of exacerbation and remission. This review aimed to analyze the scientific research conducted to date to determine what impact different nutritional plans and dietary supplements may have on the course of UC. The latest 98 articles about nutrition and supplementation in ulcerative colitis were used to prepare the work. Certain components in food can greatly influence the course of UC, inducing changes in the composition and function of the gut microbiome. This activity may be an important part of therapy for people with IBD. The Mediterranean diet has shown the most promising results in the treatment of patients with UC due to its high content of biologically active foods. Patients with UC may benefit from the UC Exclusion Diet (UCED); however, it is a new nutritional plan that requires further research. Patents frequently resort to unconventional diets, which, because of their frequent elimination of nutrient-rich foods, can worsen the health and nutritional status of those who follow them. The benefits of omega-3 fatty acids and probiotics supplementation may have additional therapeutic effects; however, the evidence is not unequivocal.

IL-17A, IL-17E and IL-17F as Potential Biomarkers for the Intensity of Low-Grade Inflammation and the Risk of Cardiovascular Diseases in Obese People

Low-grade inflammation is a factor that predisposes to many obesity-related comorbidities. The immune mechanisms controlling the inflammatory response related to the secretory activity of adipocytes and its consequences for the organism are still under investigation.

METHODS

84 obese adult volunteers (BMI ≥ 30 kg/m²) were tested by BIA. Serum samples were collected to analyze the concentrations of interleukins IL-17A, IL-17E and IL-17F. The subjects completed the original questionnaire, the FFQ-6 food consumption frequency questionnaire and the food diary.

RESULTS

The level of IL-17E and IL-17F was positively correlated with the BMI value and the level of IL-17E increased with the content of subcutaneous fat. Its increased blood concentration was also observed in individuals who declared that they were diagnosed with atherosclerosis and/or were taking beta-blockers. Products that were related with a low level of the above-mentioned interleukins were vegetables, groats, eggs, red meat, fast-food and alcohol. The level of these interleukins was positively correlated with the frequent consumption of confectionery and breakfast cereals. Nutrients that decreased the concentrations of IL-17 isoforms were potassium, iron, vitamins B6 and C, and folic acid.

CONCLUSIONS

Both IL-17E and IL-17F may be closely related to the intensity of low-grade inflammation and be biomarkers of cardiovascular disease risk. Food products or the nutrients they contain may affect the levels of the above-mentioned interleukins as well as IL-17A.

Antioxidant Stress and Anti-Inflammatory Activities of Egg White Proteins and Their Derived Peptides: A Review

Oxidative stress and chronic inflammation are the common pathological bases of chronic diseases such as atherosclerosis, cancer, and cardiovascular diseases, but most of the treatment drugs for chronic diseases have side effects. There is an increasing interest to identify food-derived bioactive compounds that can mitigate the pathological pathways associated with oxidative stress and chronic inflammation. Egg white contain a variety of biologically active proteins, many of which have antioxidant and anti-inflammatory activities and usually show better activity after enzymatic hydrolysis. This review covers the antioxidative stress and anti-inflammatory activities of egg white proteins and their derived peptides and clarifies their mechanism of action in vivo and in vitro. In addition, the link between oxidative stress and inflammation as well as their markers are reviewed. It suggests the potential application of egg white proteins and their derived peptides and puts forward further research prospects.

Recent Advances in Applications of Bioactive Egg Compounds in Nonfood Sectors

Egg, a highly nutritious food, contains high-quality proteins, vitamins, and minerals. This food has been reported for its potential pharmacological properties, including antibacterial, anti-cancer, anti-inflammatory, angiotensin-converting enzyme (ACE) inhibition, immunomodulatory effects, and use in tissue engineering applications. The significance of eggs and their components in disease prevention and treatment is worth more attention. Eggs not only have been known as a "functional food" to combat diseases and facilitate the promotion of optimal health, but also have numerous industrial applications. The current review focuses on different perceptions and non-food applications of eggs, including cosmetics. The versatility of eggs from an industrial perspective makes them a potential candidate for further exploration of several novel components.

Major yolk protein from sea cucumber (Stichopus japonicus) attenuates acute colitis via regulation of microbial dysbiosis and inflammatory responses

Inflammatory bowel disease afflicted individuals and most medications have adverse effects. The objection of this study is to investigate whether the major yolk protein (MYP) could aid in the remission of colitis. The function of MYP on acute colitis was assessed through a dextran sulfate sodium -induced colitis mice model. Compared to the model group, the anti-inflammatory cytokines increased significantly in the MYP group, whereas the pro-inflammatory cytokines were not significantly different between the model and treatment group. The results also showed that supplementation of MYP improved the shift in microbial community composition of mice with colitis induced by DSS. In addition, MYP supplementation enriched the contents of fecal short-chain fatty acids. The alleviation of MYP on the colitis was probably related to repair the dysbiosis state of colonic microbiota, which thus induced an increase in short-chain fatty acids level and secrete anti-inflammatory cytokines (IL-4 and IL-10). In sum, oral MYP may be a potential candidate for the attenuating of acute colitis.

Ovotransferrin exerts bidirectional immunomodulatory activities via TLR4-mediated signal transduction pathways in RAW264.7 cells

The immune regulation function of ovotransferrin (OVT) explored using the RAW264.7 was induced by lipopolysaccharide (LPS) as vitro model in this study. The results showed that RAW264.7 cultured with OVT (200 μg/ml) alone not only enhanced the phagocytic activity and the production and expression of inflammatory factors, but also expression of toll-like receptor 4 (TLR4) gene was significantly promoted by OVT. OVT (50 μg/ml) significantly inhibited the secretion and expression of inflammatory factors in LPS-stimulated RAW264.7, but CD14 and TLR4 genes expressions were no obvious effects. Inflammatory cytokines and NO secreted by OVT-induced macrophages pretreated with inhibitors of TLR4 were down-regulated. We further verified the effects of OVT on inflammatory signaling pathway-related proteins through immunofluorescence and western blotting, MyD88, TLR4 and the phosphorylation of IκBα and p65 were significantly promoted by OVT, but there was no significant effects on the phosphorylation of IRF3. OVT promoted the phosphorylation of ERK and p38 in RAW264.7 and inhibited the phosphorylated expression of MAPK in LPS-mediated inflammation. These results indicated that OVT had the bidirectional immunoregulatory function through TLR4-mediated NF-κB/MAPK signaling pathway, that is, anti-inflammatory effect of low concentration and immune-enhancing activity of high concentration were showed. That provides a theoretical utilization for the development and utilization of OVT.

Dairy-Derived and Egg White Proteins in Enhancing Immune System Against COVID-19

Coronavirus disease (COVID-19) is a global health challenge, caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) triggers a plethora of respiratory disturbances and even multiple organs failure that can be fatal. Nutritional intervention is one of the key components toward to a proper management of COVID-19 patients, especially in those requiring medication, and should thus be considered the first-line treatment. Immuno-modulation and -stimulation are currently being explored in COVID-19 management and are gaining interest by food and pharmaceutical industries. Various dietary combinations, bioactive components, nutrients and fortified foods have been reported to modulate inflammation during disease progression. Dietary combinations of dairy-derived products and eggs are gaining an increasing attention given the huge immunomodulatory and anti-inflammatory properties attributed to some of their chemical constituents. Eggs are complex dietary components containing many essential nutrients and bioactive compounds as well as a high-quality proteins. Similarly, yogurts can replenish beneficial bacteria and contains macronutrients capable of stimulating immunity by enhancing cell immunity, reducing oxidative stress, neutralizing inflammation and regulating the intestinal barriers and gut microbiome. Thus, this review highlights the impact of nutritional intervention on COVID-19 management, focusing on the immunomodulatory and inflammatory effects of immune-enhancing nutrients.

The Regulatory Effects of Licochalcone A on the Intestinal Epithelium and Gut Microbiota in Murine Colitis

The gut epithelium is a mechanical barrier that protects the host from the luminal microenvironment and interacts with the gut microflora, which influences the development and progression of ulcerative colitis (UC). Licochalcone A (LA) exerts anti-inflammatory effects against UC; however, whether it also regulates both the gut barrier and microbiota during colitis is unknown. The current study was conducted to reveal the regulatory effects of LA on the intestinal epithelium and gut microflora in C57BL/6 mice subjected to dextran sodium sulfate (DSS). Sulfasalazine (SASP) was used as the positive control. Results of clinical symptoms evaluation, hematoxylin, and eosin (H&E) staining, and enzyme-linked immunosorbent (ELISA) assays showed that LA significantly inhibited DSS-induced weight loss, disease activity index (DAI) increase, histological damage, and gut inflammation. Additionally, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and immunohistochemical (IHC) analysis showed that LA maintained the integrity of the intestinal barrier by suppressing cell apoptosis and preserving the expression of tight junction (TJ) proteins. Notably, the optimal dose of LA for gut barrier preservation was low, while that for anti-inflammatory effects was high, indicating that LA might preserve gut barrier integrity via direct effects on the epithelial cells (ECs) and TJ proteins. Furthermore, 16S rRNA analysis suggested that the regulatory effect of LA on the gut microbiota differed distinctly according to dose. Correlation analysis indicated that a low dose of LA significantly modulated the intestinal barrier-associated bacteria as compared with a moderate or high dose of LA. Western blot (WB) analysis indicated that LA exhibited anti-UC activity partly by blocking the mitogen-activated protein kinase (MAPK) pathway. Our results further elucidate the pharmacological activity of LA against UC and will provide valuable information for future studies regarding on the regulatory effects of LA on enteric diseases.

Impact of food-derived bioactive peptides on gut function and health

The gastrointestinal tract (GIT) is the largest interface between our body and the environment. It is an organ system extending from the mouth to the anus and functions for food intake, digestion, transport and absorption of nutrients, meanwhile providing protection from environmental factors, like toxins, antigens, and pathogens. Diet is one of the leading factors modulating the function of the GIT. Bioactive peptides presenting naturally in food or derived from food proteins during digestion or processing have been revealed multifunctional in diverse biological processes, including maintaining gut health and function. This review summarizes the available evidence regarding the effects of food-derived bioactive peptides on gut function and health. Findings and insights from studies based on in vitro and animal models are discussed. The gastrointestinal mucosa maintains a delicate balance between immune tolerance to nutrients and harmful components, which is crucial for the digestive system's normal functions. Dietary bioactive peptides positively impact gastrointestinal homeostasis by modulating the barrier function, immune responses, and gut microbiota. However, there is limited clinical evidence on the safety and efficacy of bioactive peptides, much less on the applications of dietary peptides for the treatment or prevention of diseases related to the GIT. Further study is warranted to establish the applications of bioactive peptides in regulating gut health and function.

Effective separation of prolyl endopeptidase from Aspergillus Niger by aqueous two phase system and its characterization and application

Aspergillus niger prolyl endopeptidase (An-PEP) has become a research focus because of its advantages in specifically cleaving the C-terminal peptide bond of proline residues, especially it was an industrial food-grade acidic PEP. Aqueous two-phase system (ATPS) was first applied for separating An-PEP from fermentation broth. Via response surface method (RSM) experiment, an effectively separation of An-PEP was achieved by ATPS containing27% (w/w) ethanol and 14.5% (w/w) (NH₄)₂SO₄ at pH 6.0 with the recovery of 90.29 ± 0.23% and purification coefficient of 15.35 ± 0.30. The purified An-PEP was characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), fourier transform infrared (FTIR) and fluorescence spectrometry. The optimum temperature and pH of An-PEP were 40 °C and 4.5-5.0, respectively. An-PEP was activated and stabilized by Ca²⁺ but inhibited by Fe³⁺. The enzymatic application of purified An-PEP was evaluated by hydrolyzing egg white protein (EWP) to prepare bioactive peptides. The obtained hydrolysates had good scavenging ability of OH and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radicals, angiotensin converting enzyme (ACE) inhibitory activity and anti-gout activity. This research realized a low-cost, high-efficiency and simple separation technology of An-PEP and provided a broader idea for the preparation of bioactive peptides and the application of An-PEP.

Sturgeon hydrolysates alleviate DSS-induced colon colitis in mice by modulating NF-κB, MAPK, and microbiota composition

Sturgeon muscle byproduct collected after caviar production is usually not fully utilized, and sometimes may be discarded, thus causing a lot of waste. Yet dietary protein hydrolysates, which may be derived from sturgeon muscle, have been reported to have versatile beneficial biological activities. Studying the biological activities of sturgeon muscle-derived hydrolysates holds much promise for adding value to sturgeon. The current study aimed to study the therapeutic anti-inflammatory effects of sturgeon muscle-derived hydrolysates and the underlying mechanisms. The administration of sturgeon hydrolysates (SH) significantly decreased the severity of DSS-induced damage, evidenced by increased body weight, colon length, and decreased disease activity index (DAI) and histological scores. SH also inhibited myeloperoxidase (MPO) activity and reduced the serum levels of IL-6, IL-1β, and TNF-α. Western blotting results revealed that SH suppressed DSS-induced activation of the NF-κB and MAPK pathways in the colon. Furthermore, SH partially restored the alteration of the gut microbiota in colitic mice. SH increased the Bacteroidetes/Firmicutes ratio and the relative abundance of Ruminococcaceae, Porphyromonadaceae, and Bacteroidetes S24-7, while decreased the abundance of potentially harmful bacteria Erysipelotrichaceae and Enterococcaceae. These results suggest that SH inhibited DSS-induced colitis by regulating the NF-κB and MAPK pathways and modulating microbiota composition.

A food pyramid, based on a review of the emerging literature, for subjects with inflammatory bowel disease

Emerging literature suggests that diet plays an important modulatory role in inflammatory bowel disease (IBD) through the management of inflammation and oxidative stress. The aim of this narrative review is to evaluate the evidence collected up till now regarding optimum diet therapy for IBD and to design a food pyramid for these patients. The pyramid shows that carbohydrates should be consumed every day (3 portions), together with tolerated fruits and vegetables (5 portions), yogurt (125ml), and extra virgin olive oil; weekly, fish (4 portions), white meat (3 portions), eggs (3 portions), pureed legumes (2 portions), seasoned cheeses (2 portions), and red or processed meats (once a week). At the top of the pyramid, there are two pennants: the red one means that subjects with IBD need some personalized supplementation and the black one means that there are some foods that are banned. The food pyramid makes it easier for patients to decide what they should eat.

Biological Activities of Egg Yolk Lipids: A Review

As one of six dietary nutrients, lipid derived from different food matrices has been extensively studied and has an appropriate application in food, medicine, and cosmetic industry. Egg is a richly nutritive food, of which proteins and lipids possess excellent functional characteristics and biological activities. In recent years, egg yolk lipid has been successively separated and investigated, such as egg yolk oil, phospholipids, and fatty acids, which have anti-inflammatory activity, antioxidant activity, cardiovascular protection, and memory improvement, involving the regulation of cell function and physiological homeostatic balance. In this paper, the biological activities and underlying benefit of egg yolk lipids and fat-soluble components have been highlighted and summarized. Meanwhile, the quantitative data of egg yolk lipids needed to achieve any of the described biological effects and recommended concentrations relevant for dietary intake are reviewed. Finally, current challenges and crucial issues of high-efficiency utilization of egg yolk lipids are also discussed.

Effect of egg consumption on inflammatory markers: a systematic review and meta-analysis of randomized controlled clinical trials

There is little evidence about whether eggs affect inflammation. The aim of this meta-analysis was to explore the effects of egg consumption on inflammation. A systematic search of online databases (Institute for Scientific Information (ISI), Scopus, Ovid, PubMed, Cochrane) was used to gather clinical trials that assessed the effect of egg consumption on circulating inflammatory biomarkers. Using a random-effects model, pooled weighted mean differences (WMD) and corresponding standard deviations (SD) were calculated. Of the 21 eligible studies found, nine trials were eligible for analysis. Eight trials assessed high-sensitivity C-reactive protein (hs-CRP), four trials assessed interleukin-6 (IL-6), and five trials assessed tumor necrosis factor-alpha (TNF-α). Egg consumption did not affect hs-CRP (WMD 0.24 mg/L; 95% CI: -0.43, 0.90; I²  = 53.8; P = 0.48), IL-6 (WMD 0.20 pg/mL; 95% CI: -0.71, 1.11; I² = 69.3; P = 0.50), and TNF-α (WMD: -0.38 pg/mL; 95% CI: -0.87, 0.10; I² = 0.00; P = 0.12) relative to controls. Overall, this meta-analysis revealed that egg consumption had no significant effect on serum biomarkers of inflammation in adults. © 2019 Society of Chemical Industry.

The anti-inflammatory activity of peptides from simulated gastrointestinal digestion of preserved egg white in DSS-induced mouse colitis

Peptides DEDTQAMPFR (DR-10), MLGATSL (ML-7), SLSFASR (SR-7), and MSYSAGF (MF-7) derived from simulated gastrointestinal digestion of preserved egg white (SGD-PEW) exerted anti-inflammatory effects on Caco-2 cells. Here, we aimed to evaluate the anti-inflammatory effects of these peptides derived from SGD-PEW in a mouse model of dextran sodium sulfate (DSS)-induced colitis. The results showed that DR-10, ML-7, SR-7 and MF-7 significantly ameliorated the clinical symptoms of DSS-induced mice colitis, such as weight loss, disease activity index (DAI), colon shortening, spleen hypertrophy and histological scores. Treatment with DR-10, ML-7, SR-7 and MF-7 also significantly inhibited the local secretion of pro-inflammatory cytokines TNF-α and IL-6 and markedly decreased the gene expression of pro-inflammatory cytokines, including TNF-α, IL-6, IL-17, IL-1β, IFN-γ and MCP-1, in DSS-induced mice colitis. Overall, MF-7 showed the best effect of alleviating DSS-induced colitis among the four peptides. These results suggested that MF-7, DR-10, ML-7 and SR-7 may be a potential promising candidate for the treatment of inflammatory bowel disease (IBD).

Implications of Antioxidant Systems in Inflammatory Bowel Disease

The global incidence of inflammatory bowel disease (IBD), a group of chronic gastrointestinal disorders, has been rising. The preponderance of evidence demonstrates that oxidative stress (OS) performs a critical function in the onset of IBD and the manner of its development. The purpose of this review is to outline the generation of reactive oxygen species and antioxidant defense mechanisms in the gastrointestinal tract and the role played by OS in marking the onset and development of IBD. Furthermore, the review demonstrates the various ways through which OS is related to genetic susceptibility and the mucosal immune response. The experimental results suggest that certain therapeutic regimens for IBD could have a favorable impact by scavenging free radicals, reducing cytokine and prooxidative enzyme concentrations, and improving the antioxidative capabilities of cells. However, antioxidative activity characterized by a high level of specificity may be fundamental for the development of clinical therapies and for relapsing IBD patients. Therefore, additional research is required to clarify the ways through which OS is related to the pathogenesis and progression of IBD.

Intervention of Dietary Dipeptide Gamma-l-Glutamyl-l-Valine (γ-EV) Ameliorates Inflammatory Response in a Mouse Model of LPS-Induced Sepsis

Sepsis, the systemic inflammatory response syndrome (SIRS) with infection is one of the leading causes of death in critically ill patients in the developed world due to the lack of effective antisepsis treatments. This study examined the efficacy of dietary dipeptide gamma-l-glutamyl-l-valine (γ-EV), which was characterized previously as an anti-inflammatory peptide, in an LPS-induced mouse model of sepsis. BALB/c mice were administered γ-EV via oral gavage followed by an intraperitoneal injection of LPS to induce sepsis. The γ-EV exhibited antisepsis activity by reducing the expression of pro-inflammatory cytokines TNF-α, IL-6, and IL-1β in plasma and small intestine. γ-EV also reduced the phosphorylation of the signaling proteins JNK and IκBα. We concluded that γ-EV could possess an antisepsis effect against bacterial infection in intestine. This study proposes a signaling mechanism whereby the calcium-sensing receptor (CaSR) allosterically activated by γ-EV stimulates the interaction of β-arrestin2 with the TIR(TLR/IL-1R) signaling proteins TRAF6, TAB1, and IκBα to suppress inflammatory signaling.

The extracellular matrix of eggshell displays anti-inflammatory activities through NF-κB in LPS-triggered human immune cells

Avian eggshell membrane (ESM) is a natural biomaterial that has been used as an alternative natural bandage on burned and cut skin injuries for >400 years in Asian countries, and is available in large quantities from egg industries. Our aim was to characterize ESM that was separated and processed from egg waste, and to study whether this material possesses anti-inflammatory properties, making it suitable as an ingredient in industrial production of low cost wound healing products. Our results show that the processed ESM particles retain a fibrous structure similar to that observed for the native membrane, and contain collagen, and carbohydrate components such as hyaluronic acid and sulfated glycosaminoglycans, as well as N-glycans, mostly with uncharged structures. Furthermore, both processed ESM powder and the ESM-derived carbohydrate fraction had immunomodulation properties in monocytes and macrophage-like cells. Under inflammatory conditions induced by lipopolysaccharide, the ESM powder and the isolated carbohydrate fraction reduced the activity of the transcription factor nuclear factor-κB. The expression of the immune regulating receptors toll-like receptor 4 and ICAM-1, as well as the cell surface glycoprotein CD44, all important during inflammation response, were down-regulated by these fractions. Interestingly, our experiments show that the two fractions regulated cytokine secretion differently: ESM depressed inflammation by increased secretion of the anti-inflammatory cytokine IL-10 while the carbohydrate fraction reduced secretions of the pro inflammatory cytokines IL-1β and IL-6. Also, the phosphorylation of p65 and p50 subunits of nuclear factor-κB, as well as nuclear localization, differed between processed ESM powder and carbohydrate fraction, suggesting different down-stream regulation during inflammation. In conclusion, processed ESM powder and its soluble carbohydrate components possess anti-inflammatory properties, demonstrating the potential of ESM as a novel biological wound dressing for treatment of chronic inflammatory wounds.

Intervention of Isomaltodextrin Mitigates Intestinal Inflammation in a Dextran Sodium Sulfate-Induced Mouse Model of Colitis via Inhibition of Toll-like Receptor-4

Isomaltodextrin (IMD), a highly branched α-glucan, is a type of resistant starch. Earlier studies have indicated that polysaccharides could prevent inflammation and can be effective in reducing the complications of chronic gastrointestinal diseases such as inflammatory bowel disease (IBD). Therefore, the aim of the present study was to evaluate the anti-inflammatory effect of IMD in dextran sodium sulfate (DSS)-induced colitis in a mouse model. IMD (0.5, 1.0, 2.5, and 5.0% (w/v)) was given orally for 23 days to female Balb/c mice, and then 5% DSS was administered to induce colitis (from day 15 onward to the end of the trial). IMD could not prevent DSS-induced weight loss or colon shortening. However, IMD could reduce inflammatory cytokines, TNF-α and IL-6, in the colon. Gene expression indicated the tendency of IMD to suppress pro-inflammatory cytokines IL-1β, MCP-1, and IL-17 and to increase an anti-inflammatory cytokine, IL-10. Further study revealed that the anti-inflammatory action of IMD mediates through inhibition of the expression of Toll-like receptor-4.

Adenine Inhibits TNF-α Signaling in Intestinal Epithelial Cells and Reduces Mucosal Inflammation in a Dextran Sodium Sulfate-Induced Colitis Mouse Model

Adenine (6-amino-6H-purine), found in molokheiya (Corchorus olitorius L.), has exerted vasorelaxation effects in the thoracic aorta. However, the mode of action of the anti-inflammatory effect of adenine is unclear. Thus, we investigated to clarify the effect of adenine on chronic inflammation of the gastrointestinal tract. In intestinal epithelial cells, adenine significantly inhibited tumor necrosis factor-α-induced interleukin-8 secretion. The inhibition of adenine was abolished under the treatment of inhibitors of adenyl cyclase (AC) and protein kinase A (PKA), indicating the effect of adenine was mediated through the AC/PKA pathway. Adenine (5, 10, and 50 mg/kg BW/day) was administered orally for 14 days to female BALB/c mice, and then 5% dextran sodium sulfate (DSS) was given to induce colitis. Adenine (5 mg/kg BW/day) significantly prevented DSS-induced colon shortening, expression of pro-inflammatory cytokines, and histological damage in the colon. These results suggest that adenine can be a promising nutraceutical for the prevention of intestinal inflammation.

Anti-inflammatory Effects of Poly-L-lysine in Intestinal Mucosal System Mediated by Calcium-Sensing Receptor Activation

Calcium-sensing receptor (CaSR) is involved in maintaining cellular homeostasis and promoting recovery of damaged intestinal epithelial cells (IECs). Poly-L-lysine (PL) is a basic polypeptide identified for its role in the activation of CaSR through allosteric binding. The primary goal of the current study was to identify the modulatory effect of PL on intestinal inflammation and to determine whether these effects were mediated by CaSR activation. We used human intestinal epithelial cell lines, Caco-2 and HT-29, to assess PL anti-inflammatory activities in vitro. We found that PL reduced the IL-8 secretion from tumor necrosis factor (TNF)-α-treated human intestinal epithelial cell lines. On the other hand, the gene expression of pro-inflammatory cytokines TNF-α, IL-6, and IL-1β was inhibited by PL supplementation. We subsequently evaluated the anti-inflammatory activity of PL in vivo using a DSS-induced mouse colitis model. PL supplementation was shown to prevent dextran sulfate sodium salt (DSS)-induced loss of weight, colitic symptoms, and shortening of colon length but maintained colonic morphology. The pro-inflammatory cytokine expression in the mouse colon, including TNF-α, IL-6, INF-γ, IL-17, and IL-1β, was significantly up-regulated by DSS treatment, but was inhibited upon PL administration. As shown by the results from both in vitro and in vivo studies, the reduction of inflammatory cytokine production caused by PL was reversed by NPS-2143 pretreatment. In the present study, we provide evidence that PL exerts anti-inflammatory effects on the gut system, which is primarily mediated by allosteric ligand activation of CaSR.

Calcium-sensing receptor (CaSR)-mediated anti-inflammatory effects of L-amino acids in intestinal epithelial cells

Calcium-sensing receptor (CaSR) plays an essential role in sensing nutrients and monitoring ion balance in the human gut. However, no discovery of CaSR-mediated anti-inflammatory effect of l-amino acids (l-AAs) on the gut system has been reported. The aim of this study is to screen and identify the anti-inflammatory activity of various l-AAs in intestinal epithelial cells (IECs) and stepwise illustrate a possible molecular mechanism for anti-inflammation. We used Caco-2 and HT-29 cell lines to evaluate the anti-inflammatory activity of l-AAs and revealed that l-tryptophan (l-Trp) and l-valine (l-Val) have strong anti-inflammatory activity consistent in both cell lines. l-Trp treatment (5 mM) reduced TNF-α-induced IL-8 secretion from HT-29 or Caco-2 cells to about 50 or 40%, respectively. l-Trp also significantly inhibited the expression of phosphorylation of JNK or IκBα to around 50% in HT-29 cells. However, the above inhibitory effects of l-Trp on inflammatory responses in TNF-α-induced HT-29 cells were abrogated by NPS-2143. The result of CaSR antagonist NPS-2143 pretreatment study suggests l-Trp exerts anti-inflammatory effects on IECs through CaSR activation. The involvement of β-arrestin2 was then found to block tumor necrosis factor (TNF)-α-induced signaling pathways after CaSR activated by l-Trp. These results validate a novel mechanism underlying CaSR agonistic l-AAs exerting anti-inflammatory effects on human intestinal epithelia.

Bioactive Egg Components and Inflammation

Inflammation is a normal acute response of the immune system to pathogens and tissue injury. However, chronic inflammation is known to play a significant role in the pathophysiology of numerous chronic diseases, such as cardiovascular disease, type 2 diabetes mellitus, and cancer. Thus, the impact of dietary factors on inflammation may provide key insight into mitigating chronic disease risk. Eggs are recognized as a functional food that contain a variety of bioactive compounds that can influence pro- and anti-inflammatory pathways. Interestingly, the effects of egg consumption on inflammation varies across different populations, including those that are classified as healthy, overweight, metabolic syndrome, and type 2 diabetic. The following review will discuss the pro- and anti-inflammatory properties of egg components, with a focus on egg phospholipids, cholesterol, the carotenoids lutein and zeaxanthin, and bioactive proteins. The effects of egg consumption of inflammation across human populations will additionally be presented. Together, these findings have implications for population-specific dietary recommendations and chronic disease risk.

The Anti-atherosclerotic Dipeptide, Trp-His, Reduces Intestinal Inflammation through the Blockade of L-Type Ca2+ Channels

Trp-His, the anti-atherosclerotic dipeptide, exerted an antiproliferative effect on vascular smooth muscle cells by L-type Ca(2+) channel blocker-like effect. The beneficial potential by the blockade of Ca(2+) channels on chronic intestinal inflammation, including inflammatory bowel disease (IBD), is unclear. Trp-His (100 or 250 mg/kg body weight/day) was administered for 14 days to BALB/c mice, and 5% dextran sodium sulfate (DSS) was administered to induce colitis in the last 7 days. Trp-His reduced DSS-induced typical colitis symptoms and cytokine expression in the colon. Trp-His inhibited interleukin (IL)-8 secretion in tumor necrosis factor (TNF)-α-stimulated HT-29 cells. The inhibitory effect of Trp-His, as well as that of Ca(2+) channel blockers, was impaired by the presence of Ca(2+) channel agonist Bay K 8644. The TNF-α-induced activation of mitogen-activated protein kinases (MAPKs) and IκBα were decreased by Trp-His. These results indicated that the anti-inflammatory effect of Trp-His may be involved in the blockade of L-type Ca(2+) channels.