Ovotransferrin alleviated acute gastric mucosal injury in BALB/c mice caused by ethanol.

Acute gastric mucosal injury is a common gastrointestinal disorder, which influences patients' life quality. It was found that ovotransferrin (OVT) reduces the abundance of Helicobacter pylori associated with gastric disease in the intestine of immunosuppressed mice. To clarify its gastric protective function, the present study investigated the effect of OVT on BALB/c mice with ethanol-induced gastric mucosal injury. Results showed that OVT attenuated the ethanol-induced gastric mucosal injury. Furthermore, OVT effectively downregulated the expression of inflammatory markers (tumor necrosis factor-α, interleukin (IL)-1ß and IL-6) but enhanced the secretion of IL-4, IL-10 and prostaglandin E2. And OVT pretreatment significantly inhibited the activation of the MAPK/NF-κB pathway. Additionally, OVT improved gastric antioxidant ability by increasing superoxide dismutase and glutathione levels and decreasing malondialdehyde and myeloperoxidase content. Pretreatment with OVT modulated the equilibrium between B-cell lymphoma-2 (Bcl-2) and Bcl-2-associated X. The above results indicated that OVT alleviated inflammatory responses, oxidative stress and apoptosis in gastric mucosal injury mice caused by ethanol.

Egg White Protein Ovotransferrin-Derived IRW (Ile-Arg-Trp) Inhibits LPS-Induced Barrier Integrity Dysfunction and Inflammation in Caco-2 Cells.

Tripeptide IRW derived from egg ovotransferrin was initially identified to be an inhibitor of angiotensin-converting enzyme. Later, IRW has been shown to possess various bioactivities, including anti-inflammatory activity and the ability to suppress colitis development. Nevertheless, its role in protecting intestinal barrier integrity has not been reported. This study aims to investigate the effect of IRW on inhibiting intestinal barrier dysfunction and inflammation in lipopolysaccharide (LPS)-treated Caco-2 cells. Pretreatment with IRW could mitigate the LPS-induced reduction of transepithelial electronic resistance values and decrease the paracellular permeation of differentiated Caco-2 cell monolayers. Meanwhile, IRW restored the expression level and cell surface distribution of the tight junction protein occludin. Furthermore, IRW showed LPS-neutralizing activity and could significantly inhibit LPS-induced activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. In conclusion, our study demonstrated the ability of IRW to prevent LPS-induced intestinal barrier dysfunction and prohibit inflammatory responses.

Antimicrobial defenses of table eggs: Importance of antibacterial proteins in egg white as a function of hen age in an extended production cycle.

The importance of egg natural defences to prevent bacterial contamination and their relation with hen age in extended production cycles were evaluated. Egg-white from eggs of different hen age groups (up 100-weeks-old) and lines (Hy-Line white and brown) were inoculated with Gram-positive Staphylococcus aureus or Gram-negative Salmonella Typhimurium, ranging from 103-106 CFU/mL. Our results show that concentrations of egg-white lysozyme and, particularly, ovotransferrin are important to modulate bacterial survival in a dose-dependent matter. Depending on protein concentration, their effect ranges from bactericidal to bacteriostatic, with a threshold for bacterial contamination that depends also on hen age and line. The concentrations of lysozyme and ovotransferrin increased with hen age (up to 2 and 22 w/w% of total protein, respectively), and eggs laid by older hens exhibited the greatest potential to prevent the growth of the highest Salmonella inoculum (106 CFU/mL). Salmonella-penetration experiments demonstrated that non-contaminated eggs display significantly higher concentrations of antimicrobial proteins. However, eggs from older hens needed a higher concentration of these proteins (>20% ovotransferrin) to prevent bacterial contamination, showing that antimicrobial protein concentrations in egg-whites was not the only factor influencing bacterial contamination. Finally, this study demonstrated that egg-white of eggs produced by old hens are less prone to contamination by Salmonella.

Effects of ultrasound-assisted glycosylation on the interface and foaming characteristics of ovotransferrin.

Ovotransferrin (OVT) is one of the major functional proteins in egg white protein. Most of the industry only paid attention the biological activity of OVT in iron supplement, antibacterial and other aspects, few reports were carried out on its processing characteristics such as foaming, interfacial behavior such as emulsification and foaming, which was an important processing functional attribute affecting its application scenario. In this study, the effects of ultrasound-assisted glycosylation on the interface and foaming characteristics of OVT were investigated. The results showed that proper ultrasonic treatment had a significant effect on the structure and physicochemical properties of OVT glycosylation products. When ultrasonic treatment lasted for 20 min, the grafting degree of OVT was 20.98%, the particle size decreased and the absolute value of potential increased. The foaming ability of OVT increased first and then decreased after ultrasonic-assisted glycosylation treatment. The foaming ability of OVT increased from 43.54% to 96.73% and the foaming stability increased from 68.92% to 89.19% after ultrasonic-assisted glycosylation treatment for 20 min. The experimental study effectively discovered the effect of ultrasound-assisted glycosylation on the foaming property of OVT, and would provide important technical references for expanding its application in food, biology, medicine and other fields.

Ultrasonic pretreatment enhanced the glycation of ovotransferrin and improved its antibacterial activity.

This study aims to evaluate the effect of ultrasonic pretreatment combined with glycation on the structural characteristics and antibacterial activity of ovotransferrin (OVT). Firstly, OVT (purity >90%) was isolated from egg white with a simple and efficient method. After the treatment of ultrasound and glycation, the browning degree of OVT increased with the rising power of ultrasound, while the number of free amino groups obviously decreased to 25.4%. Various spectrum detection showed that the structures of OVT have changed significantly, indicating the tertiary structure became more flexible and looser. The minimal inhibitory concentration of ultrasound glycated OVT were 25.0 and 32.1 µmol/L for E. coli and S. aureus, respectively. In summary, ultrasound-assisted glycation is an effective technique to improve the biological activity of OVT.

A Novel Angiotensin Converting Enzyme 2 (ACE2) Activating Peptide: A Reflection of 10 Years of Research on a Small Peptide Ile-Arg-Trp (IRW).

IRW (Ile-Arg-Trp) was identified as an inhibitor of angiotensin converting enzyme (ACE) from egg white protein ovotransferrin through an integrated in silico digestion and quantitative structure and activity relationship prediction in 2011. Oral administration of IRW to spontaneously hypertensive rats (SHRs) can significantly reduce blood pressure, via upregulation of ACE2, but not through the inhibition of ACE. ACE2 converts Ang II into Ang (1-7), thus lowering blood pressure via Mas receptor (MasR); coinfusion of Mas receptor antagonist A779 and IRW in SHRs abolished blood pressure-lowering effect of IRW, supporting a key role of ACE2/Ang (1-7)/MasR axis. Our ongoing study further established new roles of IRW as an antioxidant, an anti-inflammatory agent, an insulin sensitizer, and a bone cell anabolic. Future studies are warranted to understand the unique structure features of this peptide, its mechanisms of action at various targets, its bioavailability and metabolism, and its possible roles toward COVID-19.

Porcine and Bovine Forms of Lactoferrin Inhibit Growth of Porcine Enterotoxigenic Escherichia coli and Degrade Its Virulence Factors.

Postweaning diarrhea (PWD) is an economically important, multifactorial disease affecting pigs within the first 2 weeks after weaning. The most common agent associated with PWD is enterotoxigenic Escherichia coli (ETEC). Currently, antibiotics are used to control PWD, and this has most likely contributed to an increased prevalence of antibiotic-resistant strains. This puts pressure on veterinarians and farmers to decrease or even abandon the use of antibiotics, but these measures need to be supported by alternative strategies for controlling these infections. Naturally derived molecules, such as lactoferrin, could be potential candidates due to their antibacterial or immune-modulating activities. Here, we analyzed the ability of bovine lactoferrin (bLF), porcine lactoferrin (pLF), and ovotransferrin (ovoTF) to inhibit ETEC growth, degrade ETEC virulence factors, and inhibit adherence of these pathogens to porcine intestinal epithelial cells. Our results revealed that bLF and pLF, but not ovoTF, inhibit the growth of ETEC. Furthermore, bLF and pLF can degrade several virulence factors produced by ETEC strains, more specifically F4 fimbriae, F18 fimbriae, and flagellin. On the other hand, ovoTF degrades F18 fimbriae and flagellin but not F4 fimbriae. An in vitro adhesion assay showed that bLF, ovoTF, and pLF can decrease the number of bacteria adherent to epithelial cells. Our findings demonstrate that lactoferrin can directly affect porcine ETEC strains, which could allow lactoferrin to serve as an alternative to antimicrobials for the prevention of ETEC infections in piglets.IMPORTANCE Currently, postweaning F4+ and F18+Escherichia coli infections in piglets are controlled by the use of antibiotics and zinc oxide, but the use of these antimicrobial agents most likely contributes to an increase in antibiotic resistance. Our work demonstrates that bovine and porcine lactoferrin can inhibit the growth of porcine enterotoxigenic E. coli strains. In addition, we also show that lactoferrin can reduce the adherence of these strains to small intestinal epithelial cells, even at a concentration that does not inhibit bacterial growth. This research could allow us to develop lactoferrin as an alternative strategy to prevent enterotoxigenic E. coli (ETEC) infections in piglets.

Multi-Omics Analysis of the Effects of Egg Ovotransferrin on the Gut Environment in Mice: Mucosal Gene Expression, Microbiota Composition, and Intestinal Structural Homeostasis.

SCOPE: Egg ovotransferrin (OVT) is considered a functional food ingredient for its various bioactivities. The objective of this work is to explore the potential biological activity of OVT on the gut health. METHODS AND RESULTS: Both young (3 week old) and adult (8 week old) mouse models are utilized in this research. Each group receives a standard diet containing either OVT (experimental group) or distilled water (control group) for a 14 day period. Transcriptome and 16S rDNA sequencing analyses are applied to characterize the gene expression in colonic epithelial cells and gut microbiota composition. In the young groups, OVT suppresses the genes correlated with lipid metabolism and signal transduction. The regulated genes in the adult groups encompass various biological processes, including lipid metabolism, signal transduction, endocrine system, and others. OVT increases the proportion of some beneficial bacteria significantly, especially Akkermansia, and inhibits some harmful bacteria. Furthermore, OVT affects mucosal morphology positively via increasing the crypt depth. OVT also increases the expression of tight junction protein occludin by 3.0- and 5.2-folds in young and adult groups, respectively. CONCLUSION: OVT exhibits some beneficial effects on the gut environment. These positive findings provide new insight into the understanding of OVT as an excellent functional ingredient.

Iron Transport Tocopheryl Polyethylene Glycol Succinate in Animal Health and Diseases.

Gut health is the starting place for maintaining the overall health of an animal. Strategies to maintain gut health are, thus, an important part in achieving the goal of improving animal health. A new strategy to do this involves two molecules: the iron transport protein ovotransferrin (IT) and α-tocopheryl polyethylene glycol succinate (TPGS), which result in the novel formulation of ITPGS. These molecules help reduce gut pathogens, while enhancing the absorption and bioavailability of therapeutic drugs, phytomedicines, and nanomedicines. This, in turn, helps to maintain normal health in animals. Maintaining the gastrointestinal tract (GIT) in its normal condition is key for successful absorption and efficacy of any nutrient. A compromised GIT, due to an imbalance (dysbiosis) in the GIT microbiome, can lead to an impaired GI barrier system with impaired absorption and overall health of the animal. The molecules in ITPGS may address the issue of poor absorption by keeping the GI system healthy by maintaining the normal microbiome and improving the absorption of nutrients through multiple mechanisms involving antioxidative, anti-inflammatory, immunomodulatory, and antimicrobial activities. The ITPGS technology can allow the dose of active pharmaceutical or herbal medicine to be significantly reduced in order to attain equal or better efficacy. With complimentary actions between IT and TPGS, ITPGS presents a novel approach to increase the bioavailability of drugs, phytoconstituents, nutrients, and nanomedicines by enhanced transport to the tissues at the site of action, while reducing gut pathogen load. The ITPGS approach appears to be a novel strategy for maintaining the health of animals by manipulation of microbiota.

Egg White Ovotransferrin Attenuates RANKL-Induced Osteoclastogenesis and Bone Resorption.

Ovotransferrin, a member of the transferrin family, is the second main protein found in egg white. Ovotransferrin was reported to have antimicrobial, antioxidant, and immunomodulating activities. The aim of this work was to characterize the cellular and molecular functions of egg white ovotransferrin on osteoclasts differentiation and function. Osteoclasts were prepared from mouse macrophage RAW 264.7 cells stimulated with receptor activator of nuclear factor κB ligand (RANKL). Ovotransferrin inhibited osteoclasts differentiation and the calcium-phosphate resorptive ability via the suppression of RANKL-induced nuclear factor κ-light chain-enhancer of activated B cells (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. Ovotransferrin induced apoptosis of matured osteoclasts, accompanied by increased expression of Bcl-2-like protein 11 (Bim) and Bcl-2-assoicated death promoter (Bad), but decreased expression of B-cell lymphoma 2 (Bcl-2) and B-cell lymphoma-extra-large (Bcl-xl). We established a novel role of egg white ovotransferrin as an inhibitor of osteoclastogenesis, which may be used for the prevention of osteoporosis.

Different incubation patterns affect selective antimicrobial properties of the egg interior: experimental evidence from eggs of precocial and altricial birds.

Avian eggs contend with omnipresent microorganisms entering the egg interior, where they affect embryo viability and hatchling phenotype. The incubation behaviour and deposition of egg white antimicrobial proteins (AMPs) vary highly across the avian altricial-precocial spectrum. Experimental evidence of how these alterations in avian reproductive strategies affect the antimicrobial properties of the precocial and altricial egg interior is lacking, however. Here, we tested the egg white antimicrobial activity in eggs of two representative model species, from each end of the avian altricial-precocial spectrum, against potentially pathogenic and beneficial probiotic microorganisms. Eggs were experimentally treated to mimic un-incubated eggs in the nest, partial incubation during the egg-laying period, the onset of full incubation and the increased deposition of two main egg white AMPs, lysozyme and ovotransferrin. We moreover assessed to what extent egg antimicrobial components, egg white pH and AMP concentrations varied as a result of different incubation patterns. Fully incubated precocial and altricial eggs decreased their antimicrobial activity against a potentially pathogenic microorganism, whereas partial incubation significantly enhanced the persistence of a beneficial probiotic microorganism in precocial eggs. These effects were most probably conditioned by temperature-dependent alterations in egg white pH and AMP concentrations. While lysozyme concentration and pH decreased in fully incubated precocial but not altricial eggs, egg white ovotransferrin increased along with the intensity of incubation in both precocial and altricial eggs. This study is the first to experimentally demonstrate that different incubation patterns may have selective antimicrobial potential mediated by species-specific effects on antimicrobial components in the egg white.

Ovotransferrin ameliorates the dysbiosis of immunomodulatory function and intestinal microbiota induced by cyclophosphamide.

In this study, the regulative effects of ovotransferrin (OVT) on immunomodulatory function and intestinal microbial dysbiosis in a mouse model injected with cyclophosphamide (CP) were investigated. The immunomodulatory effect of OVT was determined by enzyme-linked immune sorbent assay (ELISA). Gut microbial composition was determined by high-throughput sequencing of the V3-V4 region of the 16S rDNA gene. The changes in the relative abundance of the dominant microbiota were analyzed at different taxonomic levels. The results showed that OVT alleviated the immune dysfunction caused by CP. OVT improved the spleen and thymus indices and enhanced the secretion of tumor necrosis factor alpha (TNF-α), interleukin-10 (IL-10), and immunoglobulin A (IgA). In addition, OVT increased the indexes of Shannon and Simpson, suggesting the enhancement of the diversity and richness of intestinal microflora. The relative abundance of Lachnospiraceae_NK4A136_group was also increased. However, the relative abundance of Helicobacter and Desulfovibrio was significantly decreased. These results indicated that OVT, a food-derived functional component, has effects on immune regulation in the organism and ameliorates the gut microbiota disorders induced by CP, which provides a potential therapeutic utilization of avian eggs by targeting the gut microbiome.

The Ovotransferrin-Derived Peptide IRW Attenuates Lipopolysaccharide-Induced Inflammatory Responses.

IRW (Ile-Arg-Trp), a bioactive peptide isolated from egg ovotransferrin, has been shown to exert anti-inflammatory effects. In this study, the effects of IRW on inflammatory cytokines and microbiota were explored in human umbilical vein endothelial cells (HUVECs) and a lipopolysaccharide (LPS)-induced rat model of inflammatory peritonitis. Rats were injected intraperitoneally with LPS to establish peritonitis. HUVECs were exposed to IRW for 12 h before introducing LPS. Notably, IRW exerted beneficial effects against LPS-induced peritonitis, specifically, by reducing the serum levels of tumour necrosis factor (TNF)-α and interleukin (IL)-6 and myeloperoxidase (MPO) activity (P<0.05). A faecal microbiota analysis revealed that IRW significantly increased the Shannon and decreased the Simpson indices (P<0.05). Furthermore, IRW treatment significantly inhibited the LPS-induced enhancement of TNF-α, IL-8, intercellular cell adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) expression in HUVECs (P<0.05). In conclusion, IRW supplementation inhibited the inflammatory mediator synthesis and LPS-induced inflammatory responses and influenced the gut microbiota.

Antibacterial activity of lysozyme-binding proteins from chicken egg white.

The purpose of this study was to establish a method for determining the bacteriolytic activity after separation of lysozyme-binding proteins from egg white. Lysozyme-binding proteins such as ovotransferrin and ovalbumin were separated by non-denaturing two-dimensional electrophoresis (2DE) and transferred to a membrane. The lysozyme activity of the separated and immobilized egg white proteins was assessed directly to produce a non-denaturing 3D map of the egg white proteins by incorporating an axis that combined each spot's lysozyme-activity with the non-denaturing 2DE pattern. Lysozyme-ovotransferrin and lysozyme-ovalbumin complexes could be reconstructed in vitro after the cathode end fraction containing lysozyme was added to purified ovotransferrin and ovalbumin, respectively. These complexes retained lysozyme activity even after separation by non-denaturing 2DE. Furthermore, when the lysozyme-ovotransferrin complex from egg white was extracted after separation by isoelectric focusing by replacing the cathodic sodium hydroxide solution with phosphoric acid solution, the complex possessed bacteriolytic activity against both Bacillus subtilis and Escherichia coli. These methods can be applied to investigate protein complexes possessing bacteriolytic activity against a wide range of both Gram-positive and Gram-negative bacteria.

Ovotransferrin enhances intestinal immune response in cyclophosphamide-induced immunosuppressed mice.

Ovotransferrin (OVT), a glycoprotein from avian egg, which has a variety of biological activities and immunomodulatory effects. The purpose of this research was to demonstrate the effect of OVT on intestinal immunomodulatory function which used a mouse model of cyclophosphamide (CP) induced intestinal immunosuppression and injury by intraperitoneal injection of 80 mg/kg. Effects of OVT on intestinal immunomodulatory function in CP-induced immunosuppression mice were detected by flow cytometry, real-time quantitative polymerase chain reaction, enzyme-linked immunosorbent assay, and western blot. Results showed that OVT effectively increased the major histocompatibility complex class II (MHC-II) and cluster of differentiation 83 (CD83) levels to enhance intestinal dendritic cells (DCs) maturation and promoted the expression of cytokines and gene of tumor necrosis factor alpha (TNF-α), interferon-γ (IFN-γ), interleukin-4 (IL-4) and interleukin-10 (IL-10). Furthermore, the imbalance ratio of the Th1 and Th2 in the intestine was regulated to produce an immune response and the expression of immunoglobulin A (IgA) and secretory immunoglobulin A (sIgA) were increased to promote humoral immunity by OVT-treated. Meanwhile, cyclophosphamide treatment induces activation of p38 MAPK, c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) to causes intestinal damage and blockage of p38 MAPK, JNK and ERK activation contributed to the effect of OVT on the repair of intestinal damage. These results indicated that OVT may have immunomodulatory function and could be potential functional factor to regulate body intestinal immunity.

Egg White Ovotransferrin-Derived ACE Inhibitory Peptide Ameliorates Angiotensin II-Stimulated Insulin Resistance in Skeletal Muscle Cells.

SCOPE: The renin-angiotensin system (RAS) is a major contributor to the development of insulin resistance and its related complications. Egg white ovotransferrin-derived tripeptides, IRW (Ile-Arg-Trp), IQW (Ile-Gln-Trp), or LKP (Leu-Lys-Pro) are previously identified as the inhibitors of angiotensin-converting enzyme (ACE), a key enzyme in the RAS. This study aims at determining whether these peptides are effective in improving insulin resistance, and their mechanisms of action, in a rat derived skeletal muscle cell line (L6 cells). METHODS AND RESULTS: Insulin resistance is induced by treating L6 cells with 1 µm angiotensin II (Ang II) for 24 h. Effects of peptides on glucose uptake are determined using glucose uptake assay, glucose transporter 4 (GLUT4) translocation by immunofluorescence, reactive oxygen species (ROS) by dihydroethidium (DHE) staining, while insulin signaling pathway, Ang II receptor (AT1R or AT2R) levels, and NADPH oxidase activation are measured using Western Blot. Only IRW treatment significantly improves insulin resistance in L6 cells via stimulation of insulin signaling. IRW decreases Ang II-stimulated AT1R expression, ROS formation, and NADPH oxidase activation. CONCLUSIONS: Of three ACE inhibitory peptides studied, only IRW improves insulin resistance in L6 cells, at least partially via reduced AT1R expression and its anti-oxidative activity.

Antioxidant and anticancer effects of functional peptides from ovotransferrin hydrolysates.

BACKGROUND: Egg white is a good source for making functional peptides that can be used in the food industry. Ovotransferrin (OTF) is one of the major egg white proteins, with many functional properties, including antioxidant, antimicrobial and antiviral activities. However, enzymatic hydrolysis of ovotransferrin is known to further improve the functional activities of OTF. The aim of this study was to investigate the antioxidant and anticancer activities of functional peptides produced by two-step enzyme hydrolysis of OTF. RESULTS: OTF hydrolysates were prepared using promod 278P, thermolysin and a combination of the two enzymes. OTF and OTF hydrolysates showed strong antioxidant activities when analyzed using the DPPH assay. However, only OTF hydrolysates showed a strong free radical scavenging activity when NO- or ABTS-scavenging activity was measured. OTF hydrolysates showed stronger cytotoxic activities than the natural OTF against human cancer cell lines. Furthermore, OTF hydrolysates prepared with promod 278P + thermolysin combination showed the strongest cytotoxic activity, and their IC50 values were 0.79, 0.78, 0.92 and 0.78 mg mL-1 against AGS, LoVo, HT-29 and HeLa, respectively. CONCLUSION: These results indicated that the two-step enzyme hydrolysates of OTF have great potential for use as a food ingredient with antioxidant and anticancer activities. © 2017 Society of Chemical Industry.

In vitro cytotoxic and ACE-inhibitory activities of promod 278P hydrolysate of ovotransferrin from chicken egg white.

Peptides released from egg proteins via enzymatic hydrolysis show various bioactivities such as antimicrobial, antioxidant, antihypertensive, and immunomodulatory properties. The objective of this study was to investigate the cytotoxic and Angiotensin Converting Enzyme (ACE)-inhibitory activities of ovotransferrin and its promod 278P enzyme hydrolysate. Ovotransferrin from egg white was hydrolyzed using promod 278P at 45°C for 3 hours. Using the MTT assay, the cytotoxicity of ovotransferrin and promod 278P hydrolysate of ovotransferrin were evaluated in human cancer cell lines of various tissue origins. The ACE-inhibitory activity was determined using the cleavage of a chromogenic substrate -Hip-His-Leu. The promod 278P hydrolysate of ovotransferrin showed a potent cytotoxicity (>90%) at 20 mg/mL in all cancer cell lines tested, but ovotransferrin did not. The IC50 value of the promod 278P hydrolysate of ovotransferrin against 5 different cancer cells were 10.05 ± 1.55, 3.45 ± 0.94, 4.43 ± 1.87, 4.92 ± 0.63, and 10.43 ± 3.91 mg/mL for MCF-7, HeLa, HepG2, HT-29, and LoVo cells, respectively. The promod 278P hydrolysate of ovotransferrin showed a strong ACE-inhibiting activity: at 10 mg/mL level, the hydrolysate showed 76.82 ± 1.28% inhibition to ACE-inhibitory activity, and 73.33 ± 2.56%, 56.85 ± 1.84%, 50.32 ± 3.71%, 17.30 ± 0.13%, and 4.52 ± 6.83% inhibitory activity at 5, 2.5, 1.25, 0.625, and 0.3125 mg/mL level, respectively. The IC50 value of the promod 278P hydrolysate of ovotransferrin was 1.53 ± 0.20 mg/mL. However, ovotransferrin did not show any inhibitory effect to angiotensin-converting enzyme activity. This result indicated that the promod 278P hydrolysate of ovotransferrin has a great potential as an anticancer and antihypertension agent for humans, but the information on the peptides responsible for the functional activities is not available yet.

Immunomodulatory effect of protease hydrolysates from ovotransferrin.

Proteins and bioactive peptides in avian egg white exert diverse biological activities. This study is designed to investigate the effect of protease hydrolysates from ovotransferrin (OVT) on bone marrow-derived dendritic cells (BMDCs) maturation. The results show that OVT-derived pepsin hydrolysate effectively inhibits lipopolysaccharide (LPS)-induced BMDCs maturation by reducing the expression levels of MHC-II, CD83, CD86 and the production of TNF-α, IL-12p70, and RANTES, but increases the production of IL-10. In addition, OVT-derived pepsin hydrolysate impairs the ability of LPS-stimulated BMDCs to induce allogeneic T lymphocyte proliferation and decreases the production of IFN-γ by activated T cells. In contrast, OVT-derived trypsin hydrolysate induces DCs maturation in terms of increasing the expression levels of MHC-II and the costimulatory molecules CD83 and CD86 and the production of TNF-α, IL-12p70 and RANTES. Furthermore, OVT-derived trypsin hydrolysate improves the ability of LPS-stimulated DCs to induce allogeneic T lymphocyte activation. Blockage of LPS-induced p38 MAPK and JNK activation and inducing ERK activation contribute to the inhibitory effect of OVT-derived pepsin hydrolysate on DCs, whereas OVT-derived trypsin hydrolysate induces DCs maturation through JNK and ERK activation. These results indicate that OVT-derived protease hydrolysate have an immunomodulatory function and could be applied as a potential functional food ingredient to regulate body immunity by modulating DC maturation.

The Nutraceutical Properties of Ovotransferrin and Its Potential Utilization as a Functional Food.

Ovotransferrin or conalbumin belong to the transferrin protein family and is endowed with both iron-transfer and protective activities. In addition to its well-known antibacterial properties, ovotransferrin displays other protective roles similar to those already ascertained for the homologous mammalian lactoferrin. These additional functions, in many cases not directly related to iron binding, are also displayed by the peptides derived from partial hydrolysis of ovotransferrin, suggesting a direct relationship between egg consumption and human health.