Immunomodulatory and anticancer protein hydrolysates (peptides) from food proteins: A review

A highly active angiotensin I-converting enzyme inhibitory peptide KAKW designed based on the role of C-terminal residue, and its antihypertensive effects on spontaneously hypertensive rats

Angiotensin converting enzyme (ACE) inhibitory peptide KAKP with IC50 of 7.23 ± 0.30 μM was identified from trypsin hydrolysate of pistachio (Pistacia vera L.) through multiple purifications. A series of peptides were designed based on KAKP to reveal the role of the C-terminal residue in the ACE inhibition, including KAK-Xaa (hydrophobic residue), KAK and KAPK. The designed peptide KAKW exhibited a superior ACE inhibitory effect with IC50 of 2.02 ± 0.20 μM. Molecular docking discovered that the hydrophobic C-terminal residues with ring structure facilitated the interaction with Zn2+ and π-π interactions within the ACE active pocket. Isothermal titration calorimetry revealed that the thermodynamic property of KAKW was enthalpy-driven with a lower Kd (57.7 nM) than KAKP (141 nM). KAKW could decrease 20 mmHg SBP at 4 h and 18 mmHg DBP at 6 h during the acute trial of spontaneously hypertensive rats (SHRs), compared to that Lisinopril dropped 33 mmHg SBP and 28 mmHg DBP at 2 h. After a subacute administration of KAKW for 4 w, the strong inhibition of 61.6 % serum ACE activity and the reduction of 33.3 % angiotensin Ⅱ level were achieved. Although KAKW was less potent than Lisinopril, it provided a more moderate and sustained reduction in blood pressure, beneficial for long-term hypertension management. Meanwhile, KAKW ameliorated gut microbiota dysbiosis in SHRs and increased the levels of fecal short-chain fatty acids, demonstrating advantages over Lisinopril in modulating gut microbiota. This work provides a novel scheme for structure-activity study and a prospective candidate for hypertension management.

Synergistic immunomodulatory effect of wheat/soybean/sea cucumber peptides in chloramphenicol induced immunosuppression zebrafish

BACKGROUND

Food-derived immunomodulatory peptides serve as vital agents in promoting health by protecting the body against pathogens. The present study focused on determining the optimal ratio for combining different peptides to form a complex that enhances immune activity in immunosuppressed zebrafish.

RESULTS

We established a method for immunosuppression in zebrafish, discovering that treatment with 125 μg mL-1 chloramphenicol significantly decreased the macrophage number and neutrophil fluorescence intensity. We then assessed the immunomodulatory activity of soft-shelled turtle peptides, sea cucumber peptides (SCP), black-bone silky fowl peptides, soybean peptides (SP), wheat peptides (WP), whey protein peptides and casein hydrolysate peptides. The results of individual peptides showed that WP uniquely increased the interferon-γ level, SP most effectively increased neutrophil fluorescence intensity, and SCP increased both macrophage number and neutrophil fluorescence intensity. Using mixture design and fuzzy comprehensive evaluation methods, we identified a synergistic mixture peptides: 8.32% SCP + 20.84% SP + 70.84% WP, which had the highest score in the fuzzy comprehensive evaluation, making it the best blend for boosting zebrafish immunity.

CONCLUSION

A specific mixture of peptides (8.32% SCP + 20.84% SP + 70.84% WP) holds potential as a result of a synergistic immunomodulatory effect. © 2025 Society of Chemical Industry.

Preparation, physicochemical characterization, and immunomodulatory activity of ovalbumin peptide-selenium nanoparticles

During the preparation and development of selenium nanoparticles (SeNPs), natural bioactive peptides are added to enhance their physicochemical characteristics and functional properties. Among these properties, immunomodulatory activities, which include activating immune cells to strengthen immunity, constitute the major functions of the immune system. To obtain SeNPs with enhanced immunomodulation, ovalbumin peptide (OP) was used as a stabilizer, yielding OP-SeNPs. The physicochemical properties of OP-SeNPs were characterized. RAW264.7 macrophages were used as a model to investigate the immunomodulatory activity of OP-SeNPs. Results indicate that OP-SeNPs were zero-valent and amorphous, with a particle size of 82.23 ± 1.77 nm. SeNPs demonstrated positive interactions with the -OH, CO, CN, and NH groups of OP. In addition, OP-SeNPs activated RAW264.7 macrophages by increasing NO secretion and enhancing pinocytosis activity, indicating their ability to enhance immunomodulatory effects. Therefore, this study provides a theoretical basis for the construction and characterization of bioactive peptides and SeNP complexes.

Simulated Gastrointestinal Digestion Enhances the Immunomodulatory Activity of Ovalbumin Peptide NVMEERKIK: Mechanistic Insights into TLR4/MAPK/NF-κB Signaling Modulation

NVMEERKIK, a peptide derived from ovalbumin, exhibited remarkable immunomodulatory activity. This study investigated the effect of simulated gastrointestinal digestion on its structure and bioactivity. NVMEERKIK was found to be unstable against gastrointestinal enzymes and completely degraded into NVME, NVMEE, KIK, K, and R. Among these, NVME, which constituted 90.90% of the digest, was synthesized and demonstrated a superior immune-enhancing activity than NVMEERKIK. Specifically, NVME improved phagocytosis, NO production, and TNF-α content in RAW264.7 cells by 1.31-15.86%, 17.17-122.08%, and 0.36-16.76%, respectively. TLR4 inhibition and immunofluorescence assays revealed the strong TLR4 activation and recognition capacities of both peptides. Furthermore, the Western blot results showed that NVMEERKIK and NVME activated the MAPK/NF-κB pathway by upregulating ERK, JNK, p38, and p65, leading to enhanced activation of RAW264.7 cells. The improved immune-enhancing activity of NVMEERKIK after digestion highlighted its potential as an immunomodulatory peptide for functional food applications.

Effects of Low Molecular Weight Duck Blood Protein Hydrolysate as a Feed Additive on the Intestinal Microbiome, Antioxidant Activity, and Humoral Immune and Inflammatory Responses in Flowerhorn Fish

Food-derived bioactive peptides could serve as feed ingredients and/or feed additives. We investigated the health-promoting properties of low molecular weight duck blood protein hydrolysate (DBPH), fractionated by ultrafiltration with a 10 kDa molecular weight cut-off membrane, in flowerhorn fish. The analysis of molecular weight distribution revealed that the most common sizes of DBPH fell within the range of 3-7 kDa (39.68%), followed by >7-10 kDa (20.69%), 1-3 kDa (23.03%), and <1 kDa (9.00%). After 1 month of the feeding trial, fish fed with diets supplemented with 2% DBPH exhibited the highest growth, antioxidant activity, and humoral immune response enhancement under normal conditions. In addition, microbiome analysis confirmed that 2% DBPH possesses antimicrobial activity, as evidenced by the significant decrease in operational taxonomic units (OTUs) and alpha diversity indexes, including Chao1 and Shannon. Compared to the control group, fish that were fed with diets supplemented with 2% DBPH exhibited a significantly higher abundance of the genera Cetobacterium and Romboutsia, which could serve as indicators of the overall health and well-being of the fish. After a Streptococcus agalactiae challenge, fish fed with diets supplemented with 2% DBPH exhibited an enhanced ability to modulate inflammatory genes, including interleukin (IL)-1β, IL-6, CC, and CXC chemokine as well as antioxidant gene expression (superoxide dismutase (SOD) and catalase (CAT)). Overall, dietary supplementation with 2% DBPH could improve the overall health of the flowerhorn fish by ameliorating humoral immune response, alleviating oxidative stress, and strengthening resistance against S. agalactiae.

Phenotyping the Chemical Communications of the Intestinal Microbiota and the Host: Secondary Bile Acids as Postbiotics

The current definition of a postbiotic is a "preparation of inanimate microorganisms and/or their components that confers a health benefit on the host". Postbiotics can be mainly classified as metabolites, derived from intestinal bacterial fermentation, or structural components, as intrinsic constituents of the microbial cell. Secondary bile acids deoxycholic acid (DCA) and lithocholic acid (LCA) are bacterial metabolites generated by the enzymatic modifications of primary bile acids by microbial enzymes. Secondary bile acids function as receptor ligands modulating the activity of a family of bile-acid-regulated receptors (BARRs), including GPBAR1, Vitamin D (VDR) receptor and RORγT expressed by various cell types within the entire human body. Secondary bile acids integrate the definition of postbiotics, exerting potential beneficial effects on human health given their ability to regulate multiple biological processes such as glucose metabolism, energy expenditure and inflammation/immunity. Although there is evidence that bile acids might be harmful to the intestine, most of this evidence does not account for intestinal dysbiosis. This review examines this novel conceptual framework of secondary bile acids as postbiotics and how these mediators participate in maintaining host health.

Quantification of Peptides in Food Hydrolysate from Vicia faba

The hydrolysis of raw food sources by commercially available food-grade enzymes releases thousands of peptides. The full characterization of bioactive hydrolysates requires robust methods to identify and quantify key peptides in these food sources. For this purpose, the absolute quantification of specific peptides, part of a complex peptide network, is necessary. Protein quantification with synthetic tryptic peptides as internal standards is a well-known approach, yet the quantification of non-tryptic peptides contained in food hydrolysates is still largely unaddressed. Similarly, data analyses focus on proteomic applications, thus adding challenges to the study of specific peptides of interest. This paper presents an in-sample calibration curve methodology for the identification of three non-tryptic peptides present in a Vicia faba food hydrolysate (PeptiStrong™) using heavy synthetic peptides as both calibrants and internal standards.

Purification and Characterization of Immunomodulatory Peptides from Hydrolysates of Thunnus albacares Dark Muscle

Food-derived bioactive peptides have attracted considerable research interest and are increasingly utilized as functional ingredients in the food industry. In this study, the immunomodulatory peptides were isolated and purified from Thunnus albacares (T. albacares) enzymatic hydrolysates of muscles using gel chromatography and RP-HPLC, and their amino acid sequences were identified via LC-MS/MS. A total of six peptides were selected based on their affinity to toll-like receptors. Subsequently, these peptides were synthesized to confirm the immunomodulatory activities in vitro. Among all the tested peptides, two peptides, HDCDLLR and YGSVELDELGK, significantly enhanced cell proliferation and phagocytosis and increased the production of tumor necrosis factor-α (TNF-α), nitric oxide (NO), and interleukin-6 (IL-6). Molecular docking analysis indicated that these two peptides could stably bind to the receptors through hydrogen bonds and electrostatic and hydrophobic interactions. These findings suggested that peptides from enzymatic hydrolysates of T. albacares could be promising candidates for developing immunomodulatory agents in functional foods.

Preparation and characterization of immunopeptides isolated from pig spleen and evaluation of their immunomodulatory properties in vitro and in vivo

The importance of small bioactive peptides derived from pig spleen have been used to enhance immune responses and support intestinal health. However, there is a lack of information regarding the conformational relationship and their effects on immune function of pig spleen proteins (PSPs). The objective of this study was to prepare and assess the immunomodulatory characteristics of immunopeptides from PSP. Firstly, enzymatic hydrolysates from PSP were prepared using alkaline protease and aminopeptidase, and small hydrolysate fractions with a <3 kDa were separated by SDS-PAGE and GPC. The bioactive peptides were then identified at peaks 5 to 7 (PSP-5, 6 and 7) by HPLC and TOF-MS, which were mainly composed of Pro-Glu-Leu by LC-MS. The PSP-5 and PSP-6 pronounced greater beneficial effects on cell viability and nitric oxide (NO) production than PSP-7 in macrophage, and PSP-5 exhibited a higher immunomodulatory ability than PSP-6. In vivo, the oral administration of 25-50 mg PSP-5/kg body weight (BW) protected against cyclophosphamide (CTX)-induced immunosuppression in spleen and intestine of mouse, as evidenced by increased cytokine and sIgA productions. In conclusion, a novel set of bioactive immunopeptides derived from PSP through enzymatic hydrolysis could enhance immunomodulatory properties.

Immunomodulatory activity and molecular mechanisms of action of peptides derived from casein hydrolysate by alcalase and flavourzyme based on virtual screening

This study aimed to screen novel immunomodulatory peptides from casein hydrolysates (CH) using alcalase and flavorzyme by virtual screening, and their molecular mechanism were further studied. Based on the primary structural characteristics of immunomodulatory peptides, along with their hydrophobicity and isoelectric point, 3 novel immunomodulatory peptides (ALPMHIR, AMKPWIQPK, NPWDQVKR) were quickly found using virtual screening. These peptides exhibited strong interactions with TLR2/TLR4 through hydrogen bonding and hydrophobic interactions. Molecular docking verified that the key binding sites, such as Ile733, Ala732, and Phe774 in TLR2/TLR4 contributed to docking. Interestingly, the peptide AMKPWIQPK exhibited the strongest immunomodulatory activity and anti-inflammatory activity as 2-way immunomodulatory peptides. Based on western blot analysis and validation using specific inhibitors against MAPK/NF-κB signaling pathways, the results demonstrated that AMKPWIQPK could recognize the TLR2 and TLR4 receptor of the macrophages to upregulate the phospho-IκBα, phospho-p38, and phospho-p65, and further activated the MAPKs/NF-κB signaling pathways to enhance the immunomodulatory activity. These results confirmed that screening and optimizing immunomodulatory peptides by virtual screening and molecular docking were a novel and rapidly feasible method. The peptide AMKPWIQPK was expected to be used as natural-derived immunomodulatory active ingredients in nutritional health care and functional foods.

Enzymatic synthesis of antioxidant peptides with controllable and adjustable molecular weights using magnetically recyclable immobilized Alcalase

Enzymatic hydrolysis of proteins to obtain bioactive peptides is increasingly attractive, but the poor stability and low reusability of enzymes remain unsolved. Here, the magnetically recyclable immobilized Alcalase (Alcalase@SGO-PEGA) was constructed by immobilizing the free protease of Alcalase to the superparamagnetic graphene oxide (SGO) whose surface was modified with polyethylene glycol diamine (PEGA). The results indicate that Alcalase@SGO-PEGA significantly improved the thermostability and pH tolerance of Alcalase, withstanding temperatures up to 70 °C and pH levels up to 12. Additionally, Alcalase@SGO-PEGA with a saturation magnetizations (Ms) of 20.64 emu/g allowed for efficient recovery using external magnetic fields, and its catalytic stability was demonstrated by retaining 50 % of its initial activity after seven cycles of reuse. Using Alcalase@SGO-PEGA for the enzymatic hydrolysis of soy protein isolate, casein, bovine, serum protein, β-lactoglobulin, sesame protein and flaxseed, bioactive peptides with different molecular weights were obtained by adjusting the hydrolysis temperature and time. Additionally, the antioxidative capacity of the bioactive peptides was confirmed by their ABTS+ free radicals scavenging rate and Fe2+ chelating activity. This paper presents a novel, sustainable strategy for obtaining antioxidant peptides with adjustable molecular weights using magnetically recyclable immobilized Alcalase, advancing its application and promoting cleaner protein processing.

Novel immunomodulatory peptides from hydrolysates of the Rana spinosa (Quasipaa spinosa) meat and their immunomodulatory activity mechanism

In this study, hydrolysates of Rana spinosa meat were purified and characterized, and combined with molecular docking to screen potential immunomodulatory peptides and explore their activities and mechanisms of action. The results showed that 582 peptides were identified from the hydrolysates, and three novel immunomodulatory peptides, GIHETTYNS (1020.4512 Da), IADRMQKE (989.4964 Da), and IVRDIKEK (999.6077 Da), were obtained by molecular docking. These peptides significantly increased the proliferative activity of RAW264.7 cells and accelerated its cell cycle proceeding, promoted the production of NO, IL-6, and TNF-α, and enhanced ROS levels. The molecular docking analysis revealed that immunomodulatory peptides bound to the key regions of TLR4/MD-2 by hydrogen bonds and hydrophobic interactions, and the common sites of action were LYS A:458, ARG A:434, and ARG D: 90. Furthermore, these immunomodulatory peptides had favorable safety and stability properties in silico analysis. These novel peptides are expected to be new natural materials for immunomodulators.

Green guaje (Leucaena leucocephala) and pigmented guaje (Leucaena esculenta) as sources of antioxidant and immunomodulatory peptides

In recent years, there has been a growing interest in plant-based diets, particularly legumes, as a sustainable and healthy dietary choice. This study breaks new ground by investigating the effects of simulated gastrointestinal digestion on green (Leucaena leucocephala) and pigmented (Leucaena esculenta) guaje proteins. We evaluated the antioxidant and immunomodulatory properties of ultrafiltered fractions resulting from digestion in a macrophage model. Both fractions showed promising potential as radical scavengers. The fraction <5 kDa from pigmented guaje, even at the lowest doses tested, significantly (p < 0.05) inhibited the release of pro-inflammatory cytokines TNF-α and IL-6, and demonstrated an immunomodulatory effect by reducing the levels of ROS and NO. These findings suggest that green and pigmented guaje could be a valuable source of bioactive peptides, potentially used as a coadjutant for treating and preventing oxidative stress and inflammation-associated non-communicable diseases through the utilization of underutilized legumes.

Preparation, characterization, formation mechanism, and stability studies of zein/pectin nanoparticles for the delivery of prodigiosin

Prodigiosin (PG) is a natural compound produced by microorganisms, that is known for its promising bioactive properties. However, owing to its inherent water insolubility, low bioavailability, and poor stability, the practical application of prodigiosin remains challenging. In this work, the nanoparticles of prodigiosin-loaded zein-pectin were prepared using electrostatic deposition and antisolvent precipitation methods. The encapsulation efficiency and loading capacity of prodigiosin in Z-Pet/PG 2:1 nanoparticles were 89.05 % and 7.49 %, respectively, with a zeta potential of -23.03 mV, with a particle size was 184.13 nm. The nanoparticles were uniformly distributed and possessed a spherical morphology, as determined using scanning electron microscopy. The formation mechanism between nanoparticles has been investigated using circular dichroism, fluorescence spectroscopy, molecular docking, and Fourier-transform infrared spectroscopy, which indicated stabilization predominantly through electrostatic, hydrophobic, and hydrogen-bonding interactions. Furthermore, Z-Pet/PG 2:1 nanoparticles proved remarkable stability across a pH range from 3 to 7, NaCl concentrations below 50 mmol/L, at elevated temperatures (60, 70, and 80 °C) for 1 h, and at redispersion. Prodigiosin was progressively delivered by the nanoparticles in simulated gastrointestinal settings, with a cumulative release rate of 75.32 % in simulated intestinal fluid, thereby demonstrating enhanced bioavailability and allowing for a controlled and sustained-release in vitro. These findings indicate that Z-Pet/PG nanoparticles are a promising delivery platform for prodigiosin, and are potentially applicable to other hydrophobic compounds with limited bioavailability.

Microalgae-Derived Peptides: Exploring Bioactivities and Functional Food Innovations

A variety of bioactive peptides with unique and diverse structures could be found in microalgae with various bioactivities including antioxidant, antihypertensive, and antibacterial bioactivities. Food products containing microalgae peptides hold significant health and nutrition potential. Peptide liberation through enzymatic and other processes enhanced protein extraction, and some animal studies were conducted to verify their health-promoting effects. Various studies have focused on developing practical methods for their production, purification, and identification of bioactive peptides. The emerging trends of in silico peptide therapies, computational approaches, artificial intelligence, and the prospects of microalgae peptide research are briefly highlighted. Moreover, this article focused on the potential of microalgae-derived peptides as functional food ingredients their role in promoting health, and their future applications in nutraceutical industries. It also discussed the challenges of bioavailability in functional foods.

Bioactive peptides with potential anticancer properties from various food protein sources: status of recent research, production technologies, and developments

Recently, bioactive peptides, from natural resources, have attracted remarkable attention as nutraceutical treasures and the health benefits of their consumption have extensively been studied. Therapies based on bioactive peptides have been recognized as an innovative and promising alternative method for dangerous diseases such as cancer. Indeed, there has been enormous interest in nutraceuticals and bioactive-based chemopreventive molecules as a potential opportunity to manage chronic diseases, including cancer at different stages, rather than the traditionally used therapies. The relative safety and efficacy of these peptides in targeting only the tumor cells without affecting the normal cells make them attractive alternatives to existing pharmaceuticals for the treatment, management, and prevention of cancer, being able to act as potential physiological modulators of metabolism during their intestinal digestion. Novel bioactive peptides derived from food sources can be beneficial as anticancer nutraceuticals and provide a basis for the pharmaceutical development of food-derived bioactive peptides. Bioactive peptides can be generated through different protein hydrolysis methods and purified using advanced chromatographic techniques. Moreover, establishing bioactive peptides' efficacy and mechanism of action can provide alternative methods for cancer prevention and management. Most of the research on anticancer peptides is carried out on cell lines with very limited research being investigated in animal models or human clinical models. In this context, this review article comprehensively discusses anticancer peptides': production, isolation, therapeutic strategies, mechanism of action, and application in cancer therapy.

Towards a Quantitative Description of Proteolysis: Contribution of Demasking and Hydrolysis Steps to Proteolysis Kinetics of Milk Proteins

The hydrolysis of proteins by proteases (proteolysis) plays a significant role in biology and food science. Despite the importance of proteolysis, a universal quantitative model of this phenomenon has not yet been created. This review considers approaches to modeling proteolysis in a batch reactor that take into account differences in the hydrolysis of the individual peptide bonds, as well as the limited accessibility (masking) for the enzymes of some hydrolysis sites in the protein substrate. Kinetic studies of the proteolysis of β-casein and β-lactoglobulin by various proteolytic enzymes throughout the whole degree of hydrolysis are reviewed. The two-step proteolysis model is regarded, which includes demasking of peptide bonds as a result of opening of the protein structure at the first stage, then hydrolysis of the demasked peptide bonds. To determine the kinetics of demasking, the shift in Trp fluorescence during opening of the protein substrate is analyzed. Two stages of demasking and secondary masking are also considered, explaining the appearance of unhydrolyzed peptide bonds at the end of proteolysis with decreasing enzyme concentrations. Proteolysis of a nanosized substrate is considered for the example of tryptic hydrolysis of β-CN micelles, leading to the formation and degradation of new nanoparticles and non-monotonic changes in the secondary protein structures during proteolysis.

Deep eutectic system enhanced oat protein extraction

Oats are a rich source of plant-based proteins owing to their nutritional value, diverse functions, and high abundance. However, traditional methods for extracting oat proteins (OPs), such as alkali solution acid precipitation (ASAP), can cause environmental pollution and potentially protein denaturation. In this work, we studied the use of deep eutectic solvents (DESs) and deep eutectic system (DESys)-based methods for OP extraction. The DES are composed of ionic liquids (ILs) and choline chloride (ChCl) as hydrogen bond acceptors (HBAs), and polyols as hydrogen bond donors (HBDs) for OP extraction. By systematically investigating the extraction conditions, it was found that using ChCl as an HBA in the DESys-based method allowed for a significant increase in protein recovery yield compared to the ASAP and DES-based methods. Furthermore, the physicochemical properties of OPs extracted using the ASAP, DES, and DESys-based methods exhibited some differences, particularly in their molecular structure, amino acid composition, and thermal properties, suggesting that the properties of OP could be potentially adjusted by DESys- and DES-based methods. When considering both toxicity and protein recovery yield, the DESys-based extraction method using ChCl as the HBA is more suitable for OP extraction. This study demonstrated a green and efficient method for OP extraction that minimizes environmental impact, potentially bridging the gap between ILs and DES, and offering insights for designing new DES- or DESys-based extraction strategies for biological molecules.

Immunomodulatory peptides from sturgeon cartilage: Isolation, identification, molecular docking and effects on RAW264.7 cells

Sturgeons (Acipenseridae), ancient fish known for their caviar, produce underutilized by-products like protein-rich cartilage, which is a source of high-quality bioactive peptides. This study investigates immunomodulatory peptides from sturgeon cartilage hydrolysates mechanisms. The study found that sturgeon cartilage hydrolysate F2-7 and its key peptides(DHVPLPLP and HVPLPLP)significantly promoted RAW267.4 cell proliferation, NO release, and phagocytosis (P < 0.001).Additionally, western blotting confirmed that F2-7 enhances immune response by increasing the expression of P-IKKα/β, IΚΚ, p65, and P-p65 proteins in the NF-κB signalling pathway (P < 0.01). Molecular docking further demonstrated that DHVPLPLP and HVPLPLP bind to NF-κB pathway proteins via hydrogen bonding, with low estimated binding energies (-2.75 and -1.64; -6.04 and -4.75 kcal/mol), thus establishing their role as key immune peptides in F2-7. Therefore, DHVPLPLP and HVPLPLP have the potential to be developed as dietary supplements for immune enhancement. Their ability to enhance immune function provides a theoretical basis for novel immune supplements.

Yogurt fortified with various protein hydrolysates: Texture and functional properties

This work evaluated the impact of incorporating 1% of commercial protein hydrolysates [rice protein hydrolysate (RPH), pea protein hydrolysate (PPH), and casein hydrolysate (CH)] on the functional, microstructure, and texture properties of set yogurt. Yogurt prepared with RPH exhibited the highest viability number of Streptococcus thermophilus. The addition of three hydrolysate types to yogurt revealed significant increases in the antioxidant and ACE-inhibitory activities, where the highest values were noted for the yogurt prepared with RPH. RPH exhibited no differences in texture properties (firmness, consistency, and cohesiveness) to control yogurt. These results were confirmed by scanning electron microscope examination. RPH and control yogurts showed compacted and dense structures accompanied by small pores, whereas CH and PPH yogurt structures were characterized by coarse networks with large voids. Furthermore, there was no significant impact of adding protein hydrolysates on the overall acceptability of yogurt as indicated by a sensory panel.

Identification and anticoagulant mechanisms of novel factor XIa inhibitory peptides by virtual screening of a in silico generated deep-sea peptide database

The objective of this study was to identify novel anticoagulant peptides from the deep-sea using multiple in silico methods, and to investigate their inhibitory activity and molecular mechanisms. A deep-sea peptide database was firstly constructed by performing virtual proteolysis on protein sequences from animals inhabiting deep-sea hydrothermal vents and cold seeps. Candidate anticoagulant peptides were identified through molecular docking and binding free energy screening against FXIa as the target. Two novel anticoagulant peptides, PRNIF (IC50 = 0.67 mM) and GNDRCL (IC50 = 1.52 mM), were identified, and their anticoagulant activities were verified in vitro. PRNIF was demonstrated to be a noncompetitive inhibitor of FXIa, and caused significant prolongation of thrombin time (TT) and activated partial thromboplastin time (APTT), whereas GNDRCL markedly prolonged the APTT only. Molecular dynamics simulations demonstrated considerable conformational shifts of both anticoagulant peptides when bound to the active sites of FXIa. The lowest energy binding poses of the FXIa-peptide complexes for PRNIF and GNDRCL exhibited comparable numbers of hydrogen bonds and binding free energies. However, occupancy analysis revealed completely distinct stability characteristics of the hydrogen bond interactions. The conserved residue Asp569 in the S1 pocket of FXIa formed strong and stable hydrogen bonds as well as a salt bridge with the arginine residues of PRNIF, which were not observed in the FXIa-GNDRCL complex. To our knowledge, PRNIF represented the first FXIa inhibitory peptide derived from the deep-sea, which may contribute to the development and utilization of deep-sea peptides resources. Two deep-sea peptides may potentially serve as an alternative food-derived ingredient that could be utilized for thrombosis prevention.

Extraction, purification, and mechanism of immunomodulatory peptides obtained from silkworm pupa protein hydrolysate

Silkworm pupa, a by-product of silk reeling, is rich in protein; however, it has traditionally been used as animal feed. This study isolated and purified peptides from the enzymatic hydrolysates of silkworm pupa protein, thus effectively enhancing its utilization. The immune activity of these peptides was evaluated in macrophages, and 609 peptides were identified using LC-MS/MS. These active peptides were screened based on their toxicity, allergenic, and biological activity, and their interactions with TLR2 and TLR4/MD-2 were predicted via molecular docking. Results indicated that APFAPAPL, YLPPFNSF, and FIPNEAFAGRPF could strongly bind to TLR2 and TLR4/MD-2 through hydrogen bonding and hydrophobic interactions. These peptides were synthesized using solid-phase synthesis, and their immune activity was verified by proliferation, NO, ROS and TNF-α secretion assays. All three peptides promoted the proliferation, phagocytosis, and secretion of ROS and TNF-α by macrophages. Western blot analysis showed that the peptides activated RAW 264.7 cells via the NF-κB and MAPK signaling pathways, mediated by TLR2 and TLR4/MD-2 receptors. Therefore, this study provides a new understanding of the immunomodulatory activity of silkworm pupa proteins, implying their potential use as functional food ingredients.

Sea conch (Rapana venosa) peptide hydrolysate regulates NF-κB pathway and restores intestinal immune homeostasis in DSS-induced colitis mice

Inflammatory bowel disease (IBD) is a chronic inflammatory condition of the gastrointestinal tract. Sea conch peptide hydrolysate (CPH) was produced by enzymatic digestion of fresh conch meat with trypsin enzyme. To analyze the molecular composition, functional groups, and structural morphology of the hydrolysate, we employed liquid chromatography-mass spectrometry (LC-MS), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Results confirmed that crude protein could be effectively digested by enzymes to generate peptides. In this study, we evaluated the bioactivities of CPH on dextran sulfate solution (DSS)-induced colitis in mice. The findings demonstrated that CPH supplementation improved body weight, food and water intake, and colon length. The therapeutic efficacy and immunoregulatory effect of CPH were further determined. Our results exhibited that CPH treatment significantly ameliorated pathological symptoms by enhancing intestinal integrity, mucin production, and goblet cell count. Moreover, the immunoregulatory effect of CPH on mRNA expression levels of different pro- and anti-inflammatory cytokines was determined. Results exhibited a decrease in the expression of pro-inflammatory cytokines and an increase in anti-inflammatory cytokines in the colon. Additionally, the CPH administration modulates the nuclear factor kappa B (NF-κB) pathway, preventing DNA damage and cell death. Assays for apoptosis and DNA damage revealed that CPH reduced oxidative DNA damage and apoptosis. These findings highlight the immunomodulatory and treatment amelioration effect of CPH in reducing the severity of colitis.

Tuna sidestream valorization: a circular blue bioeconomy approach

Tuna is an economically significant seafood, harvested throughout the world, and is heavily traded due to its high nutritional quality and consumer acceptance. Tuna meat is rich in essential nutrients such as amino acids, polyunsaturated fatty acids (PUFA), and trace minerals. The huge volume of solid and liquid sidestreams generated during the processing stages of tuna is creating environmental and socioeconomic challenges in coastal areas. Different products such as fish meal, protein hydrolysates, collagen, enzymes, oil, and bone powder can be produced from tuna sidestreams. Using different nutrient recovery technologies like enzymatic hydrolysis, chemical processing, and green technologies, various categories of product value chains can be created in line with the conventional processing industry. This review attempts to provide a route map for the tuna industry for achieving the circular blue-bioeconomic objectives and reorient the irregular utilization pattern into a sustainable and inclusive path.

Soybean β-Conglycinin and Cowpea β-Vignin Peptides Inhibit Breast and Prostate Cancer Cell Growth: An In Silico and In Vitro Approach

B-cell lymphoma 2 protein (Bcl-2) is an important regulator of cell apoptosis. Inhibitors that mirror the structural domain 3 (BH3) of Bcl-2 can activate apoptosis in cancer cells, making them a promising target for anticancer treatment. Hence, the present study aimed to investigate potential BH3-mimetic peptides from two vicilin-derived legume proteins from soybean and cowpea bean. The proteins were isolated and sequentially hydrolyzed with pepsin/pancreatin. Peptides < 3 kDa from vicilin-derived proteins from soybean and cowpea beans experimentally inhibited the growth of cultivated breast and prostate cancer cells. In silico analysis allowed the identification of six potential candidates, all predicted to be able to interact with the BH3 domain. The VIPAAY peptide from the soybean β-conglycinin β subunit showed the highest potential to interact with Bcl-2, comparable to Venetoclax, a well-known anticancer drug. Further experiments are needed to confirm this study's findings.

Protein nutritional support: The prevention and regulation of colorectal cancer and its mechanism research

Colorectal cancer (CRC) is a common malignant tumor of the digestive tract in China; its incidence rates and mortality rates have been on the rise in recent years, ranking third in terms of incidence and second in mortality. Rational dietary intervention plays an important role in human health, and prevention and adjuvant treatment of CRC through dietary supplementation is the most ideal and safest way to treat the disease at present. More importantly, dietary protein is the basis of our diet and the key nutrient to maintain the normal function of the human body. Therefore, this narrative review delivered an overview of the common causes and therapeutic treatments for CRC. It emphasized the importance of dietary interventions, with a particular focus on elucidating the distinct regulatory impacts of plant proteins, animal proteins, and their mixed proteins.

Preparation, design, identification and application of self-assembly peptides from seafood: A review

Hydrogels formed by self-assembling peptides with low toxicity and high biocompatibility have been widely used in food and biomedical fields. Seafood contains rich protein resources and is also one of the important sources of natural bioactive peptides. The self-assembled peptides in seafood have good functional activity and are very beneficial to human health. In this review, the sequence of seafood self-assembly peptide was introduced, and the preparation, screening, identification and characterization. The rule of self-assembled peptides was elucidated from amino acid sequence composition, amino acid properties (hydrophilic, hydrophobic and electric), secondary structure, interaction and peptide properties (hydrophilic and hydrophobic). It was introduced that the application of hydrogels formed by self-assembled peptides, which lays a theoretical foundation for the development of seafood self-assembled peptides in functional foods and the application of biological materials.

Immunomodulatory, Anticancer, and Antioxidative Activities of Bioactive Peptide Fractions from Enzymatically Hydrolyzed White Jellyfish (Lobonema smithii)

This study aimed to develop bioactive protein hydrolysates from low-value edible jellyfish obtained from local fisheries using enzymatic hydrolysis. Fresh white jellyfish were hydrolyzed using several commercial proteases, including alcalase (WJH-Al), flavourzyme (WJH-Fl), and papain (WJH-Pa). The antioxidant, immunomodulatory, and anticancer activities of these white jellyfish hydrolysates (WJH) were investigated. The results demonstrated that the crude WJH exhibited strong antioxidant properties, including DPPH, ABTS, and hydroxyl radical scavenging activities, as well as ferric-reducing antioxidant power. Additionally, the hydrolysates showed notable immunomodulatory activity. However, all WJH samples displayed relatively low ability to inhibit HepG2 cell proliferation at the tested concentrations. Among the hydrolysates, WJH-Pa demonstrated the highest antioxidant and immunomodulatory activities and was therefore selected for further bioactive peptide isolation and characterization. Ultrafiltration membranes with three molecular weight (MW) cut-offs (1, 3, 10 kDa) were used for peptide fractionation from WJH-Pa. Six potential peptides were identified with the MW range of 1049-1292 Da, comprising 9-12 residues, which exhibited strong antioxidant and immunomodulatory activities.

Production of Protein Hydrolysates Teff (Eragrostis tef) Flour with Antioxidant and Angiotensin-I-Converting Enzyme (ACE-I) Inhibitory Activity Using Pepsin and Cynara cardunculus L. Extract

In recent years, several studies have shown the antioxidant and antihypertensive potential of bioactive peptides. Thus, bioactive peptides are likely to be a valuable substance for the development of functional foods. There are a wide variety of sources of these peptides, including several cereals. Teff is an Ethiopian-rooted cereal with an interesting nutritional profile, mainly due to its high amount of protein. In this study, teff flour was subjected to a defatting process for optimizing the protein extraction. Such extraction was performed by precipitation from its isoelectric point, a crucial step that separates the protein from other components based on their charge. The protein obtained was subjected to enzymatic hydrolysis by pepsin and Cynara cardunculus L. The antihypertensive (angiotensin-I-converting enzyme -ACE-I- inhibitory activity) and antioxidant activity (2,2-diphenyl-1-picrylhydrazyl -DPPH- radical scavenging activity) of the peptides were determined. According to the IC50 values, the results obtained showed that the peptides from teff flour show promising bioactivity compared to other cereals. Furthermore, the peptides from teff flour obtained from C. cardunculus L. showed higher antioxidant activity (defatted teff flour -DTF-: 0.59 ± 0.05; protein extract -EP- : 1.04 ± 0.11) than those obtained with pepsin (DTF: 0.87 ± 0.09; EP: 1.73 ± 0.11). However, C. cardunculus L. hydrolyzate peptides showed lower inhibitory activity of ACE-I (DTF: 0.59 ± 0.07; EP: 0.61 ± 0.05) than the pepsin hydrolyzate (DTF: 0.15 ± 0.02; EP: 0.33 ± 0.05).

Antioxidative, Glucose Management, and Muscle Protein Synthesis Properties of Fish Protein Hydrolysates and Peptides

The marine environment is an excellent source for many physiologically active compounds due to its extensive biodiversity. Among these, fish proteins stand out for their unique qualities, making them valuable in a variety of applications due to their diverse compositional and functional properties. Utilizing fish and fish coproducts for the production of protein hydrolysates and bioactive peptides not only enhances their economic value but also reduces their potential environmental harm, if left unutilized. Fish protein hydrolysates (FPHs), known for their excellent nutritional value, favorable amino acid profiles, and beneficial biological activities, have generated significant interest for their potential health benefits. These hydrolysates contain bioactive peptides which are peptide sequences known for their beneficial physiological effects. These biologically active peptides play a role in metabolic regulation/modulation and are increasingly seen as promising ingredients in functional foods, nutraceuticals and pharmaceuticals, with potential to improve human health and prevent disease. This review aims to summarize the current in vitro, cell model (in situ) and in vivo research on the antioxidant, glycaemic management and muscle health enhancement properties of FPHs and their peptides.

Immunomodulatory activity of ovotransferrin-chlorogenic acid complexes enhanced by high-intensity ultrasound (HIU): A structure-function relationship study

This study investigated the impact of high-intensity ultrasound (HIU) treatment on the physiochemical, conformational, and immunomodulatory activity of the OVT-CA complex, emphasizing the structure-function relationship. HIU treatment reduced particle size, improved dispersion, and increased electronegativity of the complex. It facilitated binding between OVT and CA, achieving a maximum degree of 45.22 mg/g CA grafting and reducing interaction time from 2 h to 15 min. HIU-induced cavitation and shear promoted the exposure of -SH and unfolding of OVT, leading to increased surface hydrophobicity of the complex and transformation of its structure from β-sheet to α-helix. Additionally, CA binds to OVT in the C-lobe region, and HIU treatment modulates the intermolecular forces governing the complex formation, particularly by reinforcing hydrogen bonding, hydrophobic interactions, and introducing electrostatic interactions. Furthermore, HIU treatment increased the immunomodulatory activity of the complex, which was attributed to complex structural changes facilitating enhanced cell membrane affinity, antigen recognition, and B-cell epitope availability. Hierarchical cluster and Pearson correlation analysis confirmed that HIU treatment duration had a greater impact than power on both the structure and activity of the complex, and an optimal HIU treatment duration within 30 min was found to be crucial for activity enhancement. Moreover, structural changes, including ζ-potential, particle size/turbidity, and surface hydrophobicity, were closely correlated with immunomodulatory activity. This study highlights the potential application of HIU in developing protein-polyphenol immunomodulatory agents for public health and food nutrition.

A new glycoprotein from pigeon egg: Study on its structure and digestive characteristics

Pigeon egg white (PEW) is widely recognized as a promising source of bioactive proteins, with a high degree of glycosylation. This study focused on the characterization of a novel glycoprotein extracted from PEW, known as ovalbumin-related protein Y (OVAY). Our investigation included an analysis of the N-glycan and protein structures of OVAY, as well as an examination of simulated gastrointestinal digestive products and the transmembrane transport mechanism of OVAY-digested peptides. The results revealed that OVAY contains two glycosylation sites (Asn 62, 215) and consists of 30 N-linked glycoforms, with the top three glycans being N6H3, N6H7S1, and N6H5. Additionally, OVAY is rich in Gal and sialic acid and exhibits a rod-like molecular structure. Furthermore, it was found that OVAY demonstrates resistance to gastric digestion, with its digested peptides primarily transported via PepT1 and endocytosis. This study provides insight into the glycoprotein structure of OVAY and elucidates its physiological activity, providing a theoretical reference for the development of a novel sialate-rich protein.

Evaluating intestinal absorption of peptide Met-Lys-Pro in casein hydrolysate using Caco-2 and human iPS cell-derived small intestinal epithelial cells

High blood pressure is a major risk factor for cardiovascular disease. Our previous study confirmed that daily intake of casein hydrolysate that contained Met-Lys-Pro (MKP) can safely lower mildly elevated blood pressure. The present study aimed to evaluate the intestinal absorption differences between peptide MKP as a casein hydrolysate and synthetic MKP alone using Caco-2 cells and human iPS cell-derived small intestinal epithelial cells (hiSIECs). MKP was transported intact through Caco-2 cells and hiSIECs with permeability coefficient (Papp) values of 0.57 ± 0.14 × 10-7 and 1.03 ± 0.44 × 10-7 cm/s, respectively. This difference in Papp suggests differences in the tight junction strength and peptidase activity of each cell. Moreover, the transepithelial transport and residual ratio of intact MKP after adding casein hydrolysate containing MKP was significantly higher than that after adding synthetic MKP alone, suggesting that other peptides in casein hydrolysate suppressed MKP degradation and increased its　transport. These findings suggest that hiSIECs could be useful for predicting the human intestinal absorption of bioactive peptides; ingesting MKP as a casein hydrolysate may also improve MKP bioavailability.

Plant-Derived as Alternatives to Animal-Derived Bioactive Peptides: A Review of the Preparation, Bioactivities, Structure-Activity Relationships, and Applications in Chronic Diseases

Background/Objectives: At present, a large number of bioactive peptides have been found from plant sources with potential applications for the prevention of chronic diseases. By promoting plant-derived bioactive peptides (PDBPs), we can reduce dependence on animals, reduce greenhouse gas emissions, and protect the ecological environment. Methods: In this review, we summarize recent advances in sustainably sourced PDBPs in terms of preparation methods, biological activity, structure-activity relationships, and their use in chronic diseases. Results: Firstly, the current preparation methods of PDBPs were summarized, and the advantages and disadvantages of enzymatic method and microbial fermentation method were introduced. Secondly, the biological activities of PDBPs that have been explored are summarized, including antioxidant, antibacterial, anticancer and antihypertensive activities. Finally, based on the biological activity, the structure-activity relationship of PDBPs and its application in chronic diseases were discussed. All these provide the foundation for the development of PDBPs. However, the study of PDBPs still has some limitations. Conclusions: Overall, PDBPs is a good candidate for the prevention and treatment of chronic diseases in humans. This work provides important information for exploring the source of PDBPs, optimizing its biological activity, and accurately designing functional foods or drugs.

Gastrointestinal digestion of food proteins: Anticancer, antihypertensive, anti-obesity, and immunomodulatory mechanisms of the derived peptides

Food proteins and their peptides play a significant role in the important biological processes and physiological functions of the body. The peptides show diverse biological benefits ranging from anticancer to antihypertensive, anti-obesity, and immunomodulatory, among others. In this review, an overview of food protein digestion in the gastrointestinal tract and the mechanisms involved was presented. As some proteins remain resistant and undigested, the multifarious factors (e.g. protein type and structure, microbial composition, pH levels and redox potential, host factors, etc.) affecting their colonic fermentation, the derived peptides, and amino acids that evade intestinal digestion are thus considered. The section that follows focuses on the mechanisms of the peptides with anticancer, antihypertensive, anti-obesity, and immunomodulatory effects. As further considerations were made, it is concluded that clinical studies targeting a clear understanding of the gastrointestinal stability, bioavailability, and safety of food-based peptides are still warranted.

A Novel Workflow for In Silico Prediction of Bioactive Peptides: An Exploration of Solanum lycopersicum By-Products

Resource-intensive processes currently hamper the discovery of bioactive peptides (BAPs) from food by-products. To streamline this process, in silico approaches present a promising alternative. This study presents a novel computational workflow to predict peptide release, bioactivity, and bioavailability, significantly accelerating BAP discovery. The computational flowchart has been designed to identify and optimize critical enzymes involved in protein hydrolysis but also incorporates multi-enzyme screening. This feature is crucial for identifying the most effective enzyme combinations that yield the highest abundance of BAPs across different bioactive classes (anticancer, antidiabetic, antihypertensive, anti-inflammatory, and antimicrobial). Our process can be modulated to extract diverse BAP types efficiently from the same source. Here, we show the potentiality of our method for the identification of diverse types of BAPs from by-products generated from Solanum lycopersicum, the widely cultivated tomato plant, whose industrial processing generates a huge amount of waste, especially tomato peel. In particular, we optimized tomato by-products for bioactive peptide production by selecting cultivars like Line27859 and integrating large-scale gene expression. By integrating these advanced methods, we can maximize the value of by-products, contributing to a more circular and eco-friendly production process while advancing the development of valuable bioactive compounds.

Study on the mechanism of mitigating radiation damage by improving the hematopoietic system and intestinal barrier with Tenebrio molitor peptides

Research on plant and animal peptides has garnered significant attention, but there is a lack of studies on the functional properties of Tenebrio molitor peptides, particularly in relation to their potential mitigating effect on radiation damage and the underlying mechanisms. This study aims to explore the protective effects of Tenebrio molitor peptides against radiation-induced damage. Mice were divided into five groups: normal, radiation model, and low-, medium-, and high-dose Tenebrio molitor peptide (TMP) groups (0.15 g per kg BW, 0.30 g per kg BW, and 0.60 g per kg BW). Various parameters such as blood cell counts, bone marrow DNA content, immune organ indices, serum levels of D-lactic acid, diamine oxidase (DAO), endotoxin (LPS), and inflammatory factors were assessed at 3 and 15 days post gamma irradiation. Additionally, the intestinal tissue morphology was examined through H&E staining, RT-qPCR experiments were conducted to analyze the expression of inflammatory factors in the intestine, and immunohistochemistry was utilized to evaluate the expression of tight junction proteins ZO-1 and Occludin in the intestine. The findings revealed that high-dose TMP significantly enhanced the hematopoietic system function in mice post radiation exposure, leading to increased spleen index, thymus index, blood cell counts, and bone marrow DNA production (p < 0.05). Moreover, TMP improved the intestinal barrier integrity and reduced the intestinal permeability. Mechanistic insights suggested that these peptides may safeguard intestinal barrier function by downregulating the gene expression of inflammatory factors TNF-α, IL-1β, and IL-6, while upregulating the expression of tight junction proteins ZO-1 and Occludin (p < 0.05). Overall, supplementation with TMP mitigates radiation-induced intestinal damage by enhancing the hematopoietic system and the intestinal barrier, offering valuable insights for further investigations into the mechanisms underlying the protective effects of these peptides against ionizing radiation.

Isolation, Characterization, and Functional Properties of Antioxidant Peptides from Mulberry Leaf Enzymatic Hydrolysates

Recent evidence suggests that mulberry leaves have good antioxidant activity. However, what the antioxidant ingredient is and how the ingredient works are still not well understood. In this study, we enzymatically hydrolyze mulberry leaf proteins (MLPs) using neutral protease and find that the mulberry leaf protein hydrolysates (MLPHs) have stronger antioxidant activity compared to MLPs. We separate the core antioxidant components in MLPHs by ion-exchange columns and molecular sieves and identify 798 antioxidant peptides by LC-MS/MS. Through bioinformatics analysis and biochemical assays, we screen two previously unreported peptides, P6 and P7, with excellent antioxidant activities. P6 and P7 not only significantly reduce ROS in cells but also improve the activities of the antioxidant enzymes SOD and CAT. In addition, both peptides are found to exert protective effects against H2O2-induced chromatin damage and cell apoptosis. Collectively, these results provide support for the application of mulberry leaf peptides as antioxidants in the medical, food and livestock industries.

Biosynthesis, Characterization, and Bioactivity of L-Alanyl-L-tyrosine in Promoting Melanin Synthesis

L-Alanyl-L-tyrosine (L-Ala-Tyr) is a dipeptide formed by the condensation of L-alanine methyl ester and L-tyrosine. After entering the body, it can be rapidly broken down to release tyrosine. In this study, L-Ala-Tyr was successfully prepared by using α-ester acyltransferase as biocatalyst and alanine methyl ester (L-Ala-OMe) and tyrosine (L-Tyr) as acyl donor and nucleophile, respectively. The dipeptide yield was increased from 15 to 50% by optimizing the conditions: boric acid-borax (0.2 mol/L), 30°C, pH 9.5, 2:1 acyl donor to nucleophile ratio, DES (ChCl/urea), and 15%(v/v) water content. The catalytic product is then isolated and purified. The structure of the product was identified by high-performance liquid chromatography, mass spectrometry, proton nuclear magnetic resonance, and carbon spectroscopy. Its biological activity was preliminarily determined by the B16-F10 mouse melanoma cell model. The results showed that the purity of L-Ala-Tyr prepared by the separation and purification method of this study was 96.8%, and the mass spectrometry and nuclear magnetic resonance spectroscopy showed that the structure of the peptide was consistent with the expected structure. In addition, the preliminary physiological activity identification results show that L-Ala-Tyr has no toxic effect on cells in the concentration range of 100-800 μmol·L-1, and at the optimal concentration, compared with the positive control 8-methoxypsoralen, it can promote the production of melanin.

A novel peptide derived from Zingiber cassumunar rhizomes exhibits anticancer activity against the colon adenocarcinoma cells (Caco-2) via the induction of intrinsic apoptosis signaling

This paper presents the initial exploration of the free radical scavenging capabilities of peptides derived from protein hydrolysates (PPH) obtained from Zingiber cassumunar rhizomes (Phlai). To replicate the conditions of gastrointestinal digestion, a combination of pepsin and pancreatin proteolysis was employed to generate these hydrolysates. Subsequently, the hydrolysate underwent fractionation using molecular weight cut-off membranes at 10, 5, 3, and 0.65 kDa. The fraction with a molecular weight less than 0.65 kDa exhibited the highest levels ABTS, DPPH, FRAP, and NO radical scavenging activity. Following this, RP-HPLC was used to further separate the fraction with a molecular weight less than 0.65 kDa into three sub-fractions. Among these, the F5 sub-fraction displayed the most prominent radical-scavenging properties. De novo peptide sequencing via quadrupole-time-of-flight-electron spin induction-mass spectrometry identified a pair of novel peptides: Asp-Gly-Ile-Phe-Val-Leu-Asn-Tyr (DGIFVLNY or DY-8) and Ile-Pro-Thr-Asp-Glu-Lys (IPTDEK or IK-6). Database analysis confirmed various properties, including biological activity, toxicity, hydrophilicity, solubility, and potential allergy concerns. Furthermore, when tested on the human adenocarcinoma colon (Caco-2) cell line, two synthetic peptides demonstrated cellular antioxidant activity in a concentration-dependent manner. These peptides were also assessed using the FITC Annexin V apoptosis detection kit with PI, confirming the induction of apoptosis. Notably, the DY-8 peptide induced apoptosis, upregulated mRNA levels of caspase-3, -8, and -9, and downregulated Bcl-2, as confirmed by real-time quantitative polymerase chain reaction (RT-qPCR). Western blot analysis indicated increased pro-apoptotic Bax expression and decreased anti-apoptotic Bcl-2 expression in Caco-2 cells exposed to the DY-8 peptide. Molecular docking analysis revealed that the DY-8 peptide exhibited binding affinity with Bcl-2, Bcl-xL, and Mcl-1, suggesting potential utility in combating colon cancer as functional food ingredients.

Anti-hyperuricemia bioactive peptides: a review on obtaining, activity, and mechanism of action

Hyperuricemia, a disorder of uric acid metabolism, serves as a significant risk factor for conditions such as hypertension, diabetes mellitus, renal failure, and various metabolic syndromes. The main contributors to hyperuricemia include overproduction of uric acid in the liver or impaired excretion in the kidneys. Despite traditional clinical drugs being employed for its treatment, significant health concerns persist. Recently, there has been growing interest in utilizing protein peptides sourced from diverse food origins to mitigate hyperuricemia. This article provides a comprehensive review of bioactive peptides with anti-hyperuricemia properties derived from animals, plants, and their products. We specifically outline the methods for preparing these peptides from food proteins and elucidate their efficacy and mechanisms in combating hyperuricemia, supported by in vitro and in vivo evidence. Uric acid-lowering peptides offer promising prospects due to their safer profile, enhanced efficacy, and improved bioavailability. Therefore, this review underscores significant advancements and contributions in identifying peptides capable of metabolizing purine and/or uric acid, thereby alleviating hyperuricemia. Moreover, it offers a theoretical foundation for the development of functional foods incorporating uric acid-lowering peptides.

Antioxidant and antiproliferative activity of enzymatic hydrolysates from red tilapia (Oreochromis spp.) viscera

The antioxidant and antiproliferative activity of red tilapia (Oreochromis spp.) viscera hydrolysates (RTVH) was evaluated. For that, the hydrolysates was applied to three cancer cell lines (HepG2, Huh7 and SW480) and the control (CCD-18Co). Finally, the line on which the hydrolysate had the greatest effect (SW480) and the control (CCD-18Co) were subjected to the ApoTox-Glo Triplex Assay to determine apoptosis, toxicity, and cell viability. The result showed that hydrolysate had a dose-dependent cytotoxic effect selective on the three cancer cell lines, compared to the control cells. There is a relationship between the antioxidant capacity of RTVHs and their antiproliferative capacity on cancer cells evaluated, which achieved cell viability by action of RTVH of 34.68 and 41.58 and 25.41 %, to HepG2, Huh7 and SW480, respectively. The action of RTVH on cancer cell line SW480 is not due to the induction of apoptosis but to the rupture of the cell membrane.

Identification and Molecular Mechanism of Novel Two-Way Immunomodulatory Peptides from Ovalbumin: In Vitro Cell Experiments, De Novo Sequencing, and Molecular Docking

The purpose of this study was to identify ovalbumin-derived immunomodulatory peptides by in vitro cell experiments, de novo sequencing, and molecular docking. Ovalbumin hydrolysates were prepared by two enzymes (alkaline protease and papain) individually, sequentially, or simultaneously, respectively. The simultaneous enzymatic hydrolysate (OVAH) had a high degree of hydrolysis (38.12 ± 0.48%) and exhibited immune-enhancing and anti-inflammatory activities. A total of 160 peptides were identified by LC-MS/MS in OVAH. Three novel peptides NVMEERKIK, ADQARELINS, and WEKAFKDE bound to TLR4-MD2 through hydrogen bonds and hydrophobic interactions with high binding affinity and binding energies of -181.40, -178.03, and -168.12 kcal/mol, respectively. These three peptides were synthesized and validated for two-way immunomodulatory activity. NVMEERKIK exhibiting the strongest immunomodulatory activity, increased NO and TNF-α levels by 128.69 and 38.01%, respectively, in normal RAW264.7 cells and reduced NO and TNF-α levels by 27.31 and 39.13%, respectively, in lipopolysaccharide-induced inflammatory RAW264.7 cells. Overall, this study first revealed that ovalbumin could be used as an immunomodulatory source for controlling inflammatory factor secretion.

Beef peptides mitigate skeletal muscle atrophy in C2C12 myotubes through protein degradation, protein synthesis, and the oxidative stress pathway

This study aimed to investigate the potential of beef peptides (BPs) in mitigating muscle atrophy induced by dexamethasone (DEX) with underlying three mechanisms in vitro (protein degradation, protein synthesis, and the oxidative stress pathway). Finally, the anti-atrophic effect of BPs was enhanced through purification and isolation. BPs were generated using beef loin hydrolyzed with alcalase/ProteAX/trypsin, each at a concentration of 0.67%, followed by ultrafiltration through a 3 kDa cut-off. BPs (10-100 μg mL-1) dose-dependently counteracted the DEX-induced reductions in myotube diameters, differentiation, fusion, and maturation indices (p < 0.05). Additionally, BPs significantly reduced FoxO1 protein dephosphorylation, thereby suppressing muscle-specific E3 ubiquitin ligases such as muscle RING-finger containing protein-1 and muscle atrophy F-box protein in C2C12 myotubes at concentrations exceeding 25 μg mL-1 (p < 0.05). BPs also enhanced the phosphorylation of protein synthesis markers, including mTOR, 4E-BP1, and p70S6K1, in a dose-dependent manner (p < 0.05) and increased the mRNA expression of antioxidant enzymes. Fractionated peptides derived from BPs, through size exclusion and polarity-based fractionation, also demonstrated enhanced anti-atrophic effects compared to BPs. These peptides downregulated the mRNA expression of primary muscle atrophy markers while upregulated that of antioxidant enzymes. Specifically, peptides GAGAAGAPAGGA (MW 924.5) and AFRSSTKK (MW 826.4) were identified from fractionated peptides of BPs. These findings suggest that BPs, specifically the peptide fractions GAGAAGAPAGGA and AFRSSTKK, could be a potential strategy to mitigate glucocorticoid-induced skeletal muscle atrophy by reducing the E3 ubiquitin ligase activity.

Maximizing crustaceans (shrimp, crab, and lobster) by-products value for optimum valorization practices: A comparative review of their active ingredients, extraction, bioprocesses and applications

BACKGROUND

The processing of the three major crustaceans (shrimp, lobster, and crab) is associated with inevitable by-products, high waste disposal costs, environmental and human health issues, loss of multiple biomaterials (chitin, protein hydrolysates, lipids, astaxanthin and minerals). Nowadays, these bioresources are underutilized owing to the lack of effective and standardized technologies to convert these materials into valued industrial forms.

AIM OF REVIEW

This review aims to provide a holistic overview of the various bioactive ingredients and applications within major crustaceans by-products. This review aims to compare various extraction methods in crustaceans by-products, which will aid identify a more workable platform to minimize waste disposal and maximize its value for best valorization practices.

KEY SCIENTIFIC CONCEPTS OF REVIEW

The fully integrated applications (agriculture, food, cosmetics, pharmaceuticals, paper industries, etc.) of multiple biomaterials from crustaceans by-products are presented. The pros and cons of the various extraction methods, including chemical (acid and alkali), bioprocesses (enzymatic or fermentation), physical (microwave, ultrasound, hot water and carbonic acid process), solvent (ionic liquids, deep eutectic solvents, EDTA) and electrochemistry are detailed. The rapid development of corresponding biotechnological attempts present a simple, fast, effective, clean, and controllable bioprocess for the comprehensive utilization of crustacean waste that has yet to be applied at an industrial level. One feasible way for best valorization practices is to combine innovative extraction techniques with industrially applicable technologies to efficiently recover these valuable components.

Lysozyme Peptides as a Novel Nutra-Preservative to Control Some Food Poisoning and Food Spoilage Microorganisms

Foodborne illnesses and microbial food contamination are crucial concerns and still issues of great worldwide concern. Additionally, the serious health hazards associated with the use of chemical preservatives in food technology. Lysozyme (Lz) is an active protein against Gram-positive bacterial cell wall through its muramidase lytic activity; however, several authors could identify some antimicrobial peptides derived from Lz that have an exaggerated and broad-spectrum antibacterial activity. Therefore, a lysozyme peptides preparation (LzP) is developed to broaden the Lz spectrum. In this work, we investigated the potential efficacy of LzP as a novel Nutra-preservative (food origin) agent against some pathogenic and spoilage bacteria. Our results showed that LzP demonstrated only 11% of the lysozyme lytic activity. However, LzP exhibited strong antibacterial activity against Escherichia coli, Salmonella enteritidis, and Pseudomonas species, while Salmonella typhi and Aeromonas hydrophila exhibited slight resistance. Despite the lowest LzP concentration (0.1%) employed, it performs stronger antibacterial activity than weak organic acids (0.3%). Interestingly, the synergistic multi-component formulation (LzP, glycine, and citric acid) could inhibit 6 log10 cfu/ml of E. coli survival growth. The effect of heat treatment on LzP showed a decrease in its antibacterial activity at 5 and 67% by boiling at 100 °C/30 min, and autoclaving at 121 °C/15 min; respectively. On the other hand, LzP acquired stable antibacterial activity at different pH values (4-7). In conclusion, LzP would be an innovative, natural, and food origin preservative to control the growth of food poisoning and spoilage bacteria in food instead chemical one.

Soil inorganic amendments produce safe rice by reducing the transfer of Cd and increasing key amino acids in brown rice

The digestibility of cadmium (Cd) in brown rice is directly related to amino acid metabolism in rice and human health. In our field study, three kinds of alkaline calcium-rich soil inorganic amendments (SIAs) at three dosages were applied to produce safe rice and improve the quality of rice in Cd-contaminated paddy. With the increased application of SIA, Cd content in iron plaque on rice root significantly increased, the transfer of Cd from rice root to grain significantly decreased, and then Cd content in brown rice decreased synchronously. The vitro digestibility of Cd in brown rice was estimated by a physiologically based extraction test. Results showed that more than 70% of Cd in brown rice could be digested by simulated gastrointestinal juice. Based on the total and digestible Cd contents in brown rice to evaluate the health risk, the application of 2.25 ton SIA/ha could produce safe rice in acidic slightly Cd-contaminated paddy soils. The amino acids (AAs) in brown rice were determined by high-performance liquid chromatography. The contents of 5 key AAs (KAAs) that actively respond to environmental changes increased significantly with the increased application of SIA. The structural equation model indicated that KAAs could be affected by the Cd translocation capacity from rice root to grain, and consequently altered the ratio of indigestible Cd in brown rice. The formation of indigestible KAAs-Cd complexes by combining KAAs (phenylalanine, leucine, histidine, glutamine, and asparagine) with Cd in brown rice could be considered a potential mechanism for reducing the digestibility of Cd.

The differential non-covalent binding of epicatechin and chlorogenic acid to ovotransferrin and the enhancing efficiency of immunomodulatory activity

Seeking safe and environmentally friendly natural immunomodulators is a pressing requirement of humanity. This study investigated the differential binding characteristics of two polar polyphenols (PP), namely epicatechin (EC) and chlorogenic acid (CA), to ovotransferrin (OVT), and explored the relationship between structural transformations and immunomodulatory activity of OVT-PP complexes. Results showed that CA exhibited a stronger affinity for OVT than EC, mainly driven by hydrogen bonds and van der Waals forces. Complexation-induced conformational variations in OVT, including static fluorescence quenching, increased microenvironment polarity surrounding tryptophan and tyrosine residues, and the transition from disordered α-helix to stable β-sheet. Furthermore, the structural conformation transformation of OVT-PP complexes facilitated the enhancement of immunomodulatory activity, with the OVT-CA (10:2) complex demonstrating the best immunomodulatory activity. Principal component analysis (PCA) and Pearson correlation analysis revealed the immunomodulatory activities of the OVT-PP complexes were influenced by surface hydrophobicity (negatively correlated), β-sheet percentage and polyphenol binding constants. It could be inferred that PP complexation increased the surface polarity of OVT, consequently enhancing its immunomodulatory activity by promoting cell membrane affinity and antigen recognition. This study provides valuable guidance for effectively utilizing polyphenol-protein complexes in enhancing immunomodulatory activity.