New peptides with immunomodulatory activity identified from rice proteins through peptidomic and in silico analysis

Recent progress in the preparation of bioactive peptides using simulated gastrointestinal digestion processes

Bioactive peptides (BAPs) represent a unique class of peptides known for their extensive physiological functions and their role in enhancing human health. In recent decades, owing to their notable biological attributes such as antioxidant, antihypertensive, antidiabetic, and anti-inflammatory activities, BAPs have received considerable attention. Simulated gastrointestinal digestion (SGD) is a technique designed to mimic physiological conditions by adjusting factors such as digestive enzymes and their concentrations, pH levels, digestion duration, and salt content. Initially established for analyzing the gastrointestinal processing of foods or their constituents, SGD has recently become a preferred method for generating BAPs. The BAPs produced via SGD often exhibit superior biological activity and stability compared with those of BAPs prepared via other methods. This review offers a comprehensive examination of the recent advancements in BAP production from foods via SGD, addressing the challenges of the method and outlining prospective directions for further investigation.

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.

Bioinformatics tools for the study of bioactive peptides from vegetal sources: evolution and future perspectives

Bioactive peptides from vegetal sources have been shown to have functional properties as anti-inflammatory, antioxidant, antihypertensive or antidiabetic capacity. For this reason, they have been proposed as an interesting and promising alternative to improve human health. In recent years, the numerous advances in the bioinformatics field for in silico prediction have speeded up the discovery of bioactive peptides, also reducing the associated costs when using an integrated approach between the classical and bioinformatics discovery. This review aims to provide an overview of the evolution, limitations and latest advances in the field of bioinformatics and computational tools, and specifically make a critical and comprehensive insight into computational techniques used to study the mechanism of interaction that allows the explanation of plant bioactive peptide functionality. In particular, molecular docking is considered key to explain the different functionalities that have been previously identified. The assumptions to simplify such a high complex environment implies a degree of uncertainty that can only be guaranteed and validated by in vitro or in vivo studies, however, the combination of databases, software and bioinformatics applications with the classical approach has become a promising procedure for the study of bioactive peptides.

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.

Study on the structure-activity relationship of rice immunopeptides based on molecular docking

Research on food-derived immunoregulatory peptides has attracted increasing attention of scientists worldwide. However, the structure-activity relationship of rice immunopeptides was not clearly. Herein, 114 rice immunopeptides were obtained by simulating the enzymatic hydrolysis of rice proteins and were further analyzed by NetMHCIipan-4.0. Subsequently, the molecular docking was used to simulate the binding of immunoreactive peptides to major histocompatibility complex class II (MHC-II) molecules. Results show that S, R, D, E, and T amino acid could easily form hydrogen bonds with MHC-II molecules, thus enhancing innate and adaptive immunity. Finally, glucose-modified rice immunopeptides were to investigate the binding of the peptides with MHC-II molecules after glycosylation modification; this provided a theoretical basis for the targeted modification of the generated immunopeptides. All in all, the present study provides a theoretical foundation to further utilize rice processing byproducts and other food products to enhance immunity.

Bioactive peptides: an alternative therapeutic approach for cancer management

Cancer is still considered a lethal disease worldwide and the patients' quality of life is affected by major side effects of the treatments including post-surgery complications, chemo-, and radiation therapy. Recently, new therapeutic approaches were considered globally for increasing conventional cancer therapy efficacy and decreasing the adverse effects. Bioactive peptides obtained from plant and animal sources have drawn increased attention because of their potential as complementary therapy. This review presents a contemporary examination of bioactive peptides derived from natural origins with demonstrated anticancer, ant invasion, and immunomodulation properties. For example, peptides derived from common beans, chickpeas, wheat germ, and mung beans exhibited antiproliferative and toxic effects on cancer cells, favoring cell cycle arrest and apoptosis. On the other hand, peptides from marine sources showed the potential for inhibiting tumor growth and metastasis. In this review we will discuss these data highlighting the potential befits of these approaches and the need of further investigations to fully characterize their potential in clinics.

Plant-Derived Proteins and Peptides as Potential Immunomodulators

The immune response of humans may be modulated by certain biopeptides. The present study aimed to determine the immunomodulatory potential of plant-derived food proteins and hydrolysates obtained from these proteins via monocatalytic in silico hydrolysis (using ficin, stem bromelainm or pepsin (pH > 2)). The scope of this study included determinations of the profiles of select bioactivities of proteins before and after hydrolysis and computations of the frequency of occurrence of selected bioactive fragments in proteins (parameter A), frequency/relative frequency of the release of biopeptides (parameters AE, W) and the theoretical degree of hydrolysis (DHt), by means of the resources and programs available in the BIOPEP-UWM database. The immunomodulating (ImmD)/immunostimulating (ImmS) peptides deposited in the database were characterized as well (ProtParam tool). Among the analyzed proteins of cereals and legumes, the best precursors of ImmD immunopeptides (YG, YGG, GLF, TPRK) turned out to be rice and garden pea proteins, whereas the best precursors of ImmS peptides appeared to be buckwheat (GVM, GFL, EAE) and broad bean (LLY, EAE) proteins. The highest number of YG sequences was released by stem bromelain upon the simulated hydrolysis of rice proteins (AE = 0.0010-0.0820, W = 0.1994-1.0000, DHt = 45-82%). However, antibacterial peptides (IAK) were released by ficin only from rice, oat, and garden pea proteins (DHt = 41-46%). Biopeptides (YG, IAK) identified in protein hydrolysates are potential immunomodulators, nutraceuticals, and components of functional food that may modulate the activity of the human immune system. Stem bromelain and ficin are also active components that are primed to release peptide immunomodulators from plant-derived food proteins.

Plant Protein-Derived Active Peptides: A Comprehensive Review

Active peptides are a class of physiologically active protein fragments, which can be prepared from different sources. In the past few decades, the production of peptides with various effects from different plant proteins continues to receive academic attention. With advances in extraction, purification, and characterization techniques, plant protein-derived active peptides continue to be discovered. They have been proven to have various functional activities such as antioxidant, antihypertensive, immunomodulatory, antimicrobial, anti-inflammatory, antidiabetic, antithrombotic, and so on. In this review, we searched Web of Science and China National Knowledge Infrastructure for relevant articles published in recent years. There are 184 articles included in this manuscript. The current status of plant protein-derived active peptides is systematically introduced, including their sources, preparation, purification and identification methods, physiological activities, and applications in the food industry. Special emphasis has been placed on the problems of active peptide exploration and the future trend. Based on these, it is expected to provide theoretical reference for the further exploitation of plant protein-derived active peptides, and promote the healthy and rapid development of active peptide industry.

Anti-inflammatory effect of two novel peptides derived from Binglangjiang buffalo whey protein in lipopolysaccharide-stimulated RAW264.7 macrophages

Whey protein hydrolysate from Binglangjiang buffalo, a unique genetic resource, has anti-inflammatory activity, but its anti-inflammatory composition and effects are unknown. The aim of this study was to investigate the anti-inflammatory peptides from Binglangjiang buffalo whey protein hydrolysate. A total of 1483 peptides were identified using LC-MS/MS, and 12 peptides were chosen for chemical synthesis using peptidomics, and then two novel anti-inflammatory peptides (DQPFFHYN (DN8) and YSPFSSFPR (YR9)) were screened out using LPS-stimulated RAW264.7 cells. The molecular weights of DN8 and YR9 with β-turn conformations were 1067.458 Da and 1087.52 Da, respectively, and showed a high in-vitro safety profile and thermal stability, but were intolerant to pepsin. Furthermore, ELISA and Western blot analysis indicated that peptides DN8 and YR9 significantly suppressed the secretion of pro-inflammatory cytokines NO, TNF-α, and IL-6 and the expression of mediators iNOS, TNF-α, and IL-6 in LPS-stimulated RAW264.7 cells. The study provides insights into the development of novel food-based anti-inflammatory nutritional supplements.

Transcriptome Analysis Reveals the Immunoregulatory Activity of Rice Seed-Derived Peptide PEP1 on Dendritic Cells

Some food-derived bioactive peptides exhibit prominent immunoregulatory activity. We previously demonstrated that the rice-derived PEP1 peptide, GIAASPFLQSAAFQLR, has strong immunological activity. However, the mechanism of this action is still unclear. In the present study, full-length transcripts of mouse dendritic cells (DC2.4) treated with PEP1 were sequenced using the PacBio sequencing platform, and the transcriptomes were compared via RNA sequencing (RNA-Seq). The characteristic markers of mature DCs, the cluster of differentiation CD86, and the major histocompatibility complex (MHC-II), were significantly upregulated after the PEP1 treatment. The molecular docking suggested that hydrogen bonding and electrostatic interactions played important roles in the binding between PEP1, MHC-II, and the T-cell receptor (TCR). In addition, the PEP1 peptide increased the release of anti-inflammatory factors (interleukin-4 and interleukin-10) and decreased the release of pro-inflammatory factors (interleukin-6 and tumor necrosis factor-α). Furthermore, the RNA-seq results showed the expression of genes involved in several signaling pathways, such as the NF-κB, MAPK, JAK-STAT, and TGF-β pathways, were regulated by the PEP1 treatment, and the changes confirmed the immunomodulatory effect of PEP1 on DC2.4 cells. This findings revealed that the PEP1 peptide, derived from the byproduct of rice processing, is a potential natural immunoregulatory alternative for the treatment of inflammation.

Modification and Solubility Enhancement of Rice Protein and Its Application in Food Processing: A Review

Rice protein is a high-quality plant-based protein source that is gluten-free, with high biological value and low allergenicity. However, the low solubility of rice protein not only affects its functional properties such as emulsification, gelling, and water-holding capacity but also greatly limits its applications in the food industry. Therefore, it is crucial to modify and improve the solubility of rice protein. In summary, this article discusses the underlying causes of the low solubility of rice protein, including the presence of high contents of hydrophobic amino acid residues, disulfide bonds, and intermolecular hydrogen bonds. Additionally, it covers the shortcomings of traditional modification methods and the latest compound improvement methods, compares various modification methods, and puts forward the best sustainable, economical, and environmentally friendly method. Finally, this article lists the uses of modified rice protein in dairy, meat, and baked goods, providing a reference for the extensive application of rice protein in the food industry.

Compositional analysis and immunomodulatory activity of blue pigment fraction (BPF) from Laba garlic

Laba garlic is a kind of garlic (Allium sativum L.) product and blue pigment fraction (BPF) is the characteristic fraction of Laba garlic. The objective of the study was to isolate BPF from Laba garlic and explore its stability, composition, antioxidant activity, and immunomodulatory activity. The results suggested BPF was unstable under alkaline conditions. Twenty-four constituents including 9 peptides and 10 saponins were detected in BPF by Q Exactive HF LC/MS anlaysis. BPF showed antioxidant activity in a dose-dependent manner. It also showed effective immunomodulatory activity at a concentration of 5 μg/mL at the cellular level and the morphology of RAW 264.7 cells changed to a polygonal and dendritic-like structure. BPF could significantly increase NO production (P < 0.05), and up-regulate the mRNA levels of TNF-α, IL-6, iNOS and NF-κB in the RT-QPCR analysis. The present study systematically analyzed the compositions of BPF for the first time, and the results suggested that BPF might be a potential immunomodulator candidate, which is beneficial for the development and application of garlic products and natural pigments.

Proteomic approach-based comparison of metabolic pathways and functional activities of whey proteins derived from Guishan and Saanen goat milk

Guishan goats, a unique goat breed in Yunnan Province, have a long history and representation, but their whey protein and function remain unclear. In this study, we carried out a quantitative analysis of the Guishan and Saanen goat whey proteome using a label-free proteomic approach. A total of 500 proteins were quantified from the 2 kinds of goat whey proteins, including 463 common proteins, 37 uniquely expressed whey proteins (UEWP), and 12 differentially expressed whey proteins (DEWP). Bioinformatics analysis indicated that UEWP and DEWP were mainly involved in cellular and immune system processes, membrane, and binding. In addition, UEWP and DEWP in Guishan goats participated primarily in metabolism and immune-related pathways, whereas Saanen goat whey proteins were associated mostly with environmental information processing-related pathways. Guishan goat whey promoted the growth of RAW264.7 macrophages more than Saanen goat whey, and significantly reduced the production of nitric oxide in lipopolysaccharide-stimulated RAW264.7 cells. This study provides a reference for further understanding these 2 goat whey proteins and finding functional active substances from them.

Identification and Molecular Mechanism of Novel Immunomodulatory Peptides from Gelatin Hydrolysates: Molecular Docking, Dynamic Simulation, and Cell Experiments

The purpose of this study was to identify donkey-hide gelatin-derived immunomodulatory peptides targeting Toll-like receptor 4-myeloid differentiation 2 (TLR4-MD2) and elucidate their binding modes using physicochemical property prediction, molecular docking, molecular dynamics simulations, and in vitro cell experiments. After hydrolyzing gelatin, 519 peptides were identified by liquid chromatography-tandem mass spectrometry. Peptides VQLSGEEK and GFSGLDGAKG bound to TLR4-MD2 with high binding affinity. In TLR4-MD2, Arg90, Ser118, Phe126, Tyr131, and Arg264 were key residues involved in the binding of these peptides. The RMSD and R_g values demonstrated that VQLSGEEK-TLR4-MD2 and GFSGLDGAKG-TLR4-MD2 complexes had stable and compact conformations. VQLSGEEK and GFSGLDGAKG were found to increase the cell viability and phagocytic activity of RAW264.7 macrophages; significantly promote the production of cytokines TNF-α, IL-1β, and IL-6 in cells; and inhibit the overproduction of nitric oxide (NO) and cytokines in lipopolysaccharide (LPS)-induced RAW264.7 cells. Our results provided preliminary evidence that VQLSGEEK and GFSGLDGAKG could function as two-way immunomodulatory peptides with immunostimulatory and anti-inflammatory activities.

Identification and virtual screening of novel anti-inflammatory peptides from broccoli fermented by Lactobacillus strains

Lactobacillus strains fermentation of broccoli as a good source of bioactive peptides has not been fully elucidated. In this work, the peptide composition of broccoli fermented by L. plantarum A3 and L. rhamnosus ATCC7469 was analyzed by peptidomics to study the protein digestion patterns after fermentation by different strains. Results showed that water-soluble proteins such as rubisco were abundant sources of peptides, which triggered the sustained release of peptides as the main target of hydrolysis. In addition, 17 novel anti-inflammatory peptides were identified by virtual screening. Among them, SIWYGPDRP had the strongest ability to inhibit the release of NO from inflammatory cells at a concentration of 25 μM with an inhibition rate of 52.32 ± 1.48%. RFR and KASFAFAGL had the strongest inhibitory effects on the secretion of TNF-α and IL-6, respectively. At a concentration of 25 μM, the corresponding inhibition rates were 74.61 ± 1.68% and 29.84 ± 0.63%, respectively. Molecular docking results showed that 17 peptides formed hydrogen bonds and hydrophobic interactions with inducible nitric oxide synthase (iNOS). This study is conducive to the high-value utilization of broccoli and reduction of the antibiotic use.

Antioxidant and immunomodulatory potency of Lacticaseibacillus rhamnosus NCDC24 fermented milk-derived peptides: A computationally guided in-vitro and ex-vivo investigation

Infections of microbial and non-microbial origins have been associated with significant immunological manifestations, thereby underscoring the need for a thorough understanding and investigation of novel immunomodulatory and antioxidant molecules that could prevent these incidences. To this end, we herein aim to identify fermented milk peptides with antioxidant and immunomodulatory properties that could be exploited for specific future applications. Our computational prediction models indicate that these peptides are non-toxic and possess considerable hydrophobicity (19.82-38.96 %) and functionality. Further analyses reveal that two of the four peptides, i.e., Pep 1 (AGWNIPM) and Pep 4 (YLGYLEQLLR), possess higher in-vitro antioxidant activity. The immunomodulatory potential of these two peptides (Pep 1 and Pep 4) is further demonstrated by using a combination of molecular simulation trajectory and ex-vivo approaches. Both peptides demonstrate ability to control the production of pro- inflammatory (TNF-α, IL-1, and IL-6) and anti-inflammatory (IL-10) cytokines as well as nitric oxide release in LPS-stimulated murine peritoneal macrophages. Similarly, peptide interferences also lead to significant (P < 0.05) improvement in macrophage phagocytic capacity. Taken together, these findings highlight the antioxidant and immunomodulatory properties of fermented milk peptides (Pep 1 and Pep 4) within the cellular environment and should facilitate prospective studies exploring such bioactive peptides and related functional molecules mediating the benefits of fermented milk products on human health.

Rapid Screening of Novel Dipeptidyl Peptidase-4 Inhibitory Peptides from Pea (Pisum sativum L.) Protein Using Peptidomics and Molecular Docking

Pea protein hydrolysates (PPHs) possess good hypoglycemic effects; however, their dipeptidyl peptidase-4 (DPP-4) inhibitory activity is poorly understood, and none of the DPP-4 inhibitory peptides have been identified from PPHs. This paper aims to rapidly screen these peptides from PPHs by combining peptidomics and molecular docking. In this study, 543 peptides were identified by peptidomics, and four peptides (IPYWTY, IPYWT, LPNYN, and LAFPGSS) with DPP-4 half-maximal inhibitory concentration (IC50) values <100 μM were screened for the first time. Significantly, peptide IPYWTY exhibited the most potent DPP-4 inhibitory activity (IC50 = 11.04 μM) mainly because it formed hydrophobic interactions with the S1 pocket in DPP-4. These results indicated that combining peptidomics and molecular docking is an effective strategy for rapidly screening DPP-4 inhibitory peptides.

In Vitro Anti-Inflammatory Activity of Three Peptides Derived from the Byproduct of Rice Processing

Inflammation is a contributing factor to the initiation and progression of many diseases, and some food-derived biofunctional peptides show high anti-inflammatory activity. In our previous study, we demonstrated that peptides derived from trypsin hydrolysis of rice protein show good immunological activity. In the present study, proteins of broken rice were extracted and identified by macroporous resin fractionation and liquid chromatography/tandem mass spectrometry (LC-MS/MS). Subsequently, a bioinformatics prediction and in silico simulation approach was used to screen for peptides showing anti-inflammatory activity, including inhibition of the production of nitric oxide and proinflammatory cytokines (interleukin-1β, interleukin-6, and tumor necrosis factor-α) by lipopolysaccharide-stimulated RAW264.7 mice macrophages. Three peptides (DNIQGITKPAIR, IAFKTNPNSMVSHIAGK, and IGVAMDYSASSKR) that demonstrated the highest binding affinity were synthesized, and their in vitro anti-inflammatory activity was investigated. This is the first study that integrates LC-MS/MS identification and bioinformatics prediction for reporting the anti-inflammatory activity of anti-inflammatory peptides derived from broken rice protein. The study findings revealed that the peptides derived from the byproduct of rice milling could be potentially used as natural anti-inflammatory alternativities.

Shrimp peptide hydrolysate modulates the immune response in cyclophosphamide immunosuppressed mice model

Bioactive peptides are naturally found in various foods and were shown to have various distinct physiological as well as medicinal benefits. In this study shrimp peptide hydrolysate (SPH) was prepared to investigate its immunomodulatory effect against cyclophosphamide (CTX) induced immunosuppressed mice. The SPH effect was also analyzed on murine macrophage (RAW264.7 cells). The findings show that SPH stimulates macrophages to form multiple pseudopodia, has no cytotoxic effect, and increases phagocytic activity in RAW264.7 cells. Furthermore, the immunosuppressed in-vivo model illustrates the improvement in various aspects, that is body weight, escalation in immune organ index, and ameliorates histopathological transformation of thymus along with the spleen. SPH enhances cell-mediated immunity by facilitating splenocyte proliferation and inhibit excessive apoptosis. Moreover, the significant outcome had been observed with the upregulation of cytokines interferon-gamma (IFN-ϒ), interleukin-2 (IL-2) level and simultaneously downregulate certain genes include interleukin-4 (IL-4) and interleukin-10 (IL-10). Additionally, SPH expedites cellular immunity by enhancing the regulation of immunoglobulin A (IgA) and immunoglobulin M (IgM). However, these findings support the hypothesis that SPH is an effective immunomodulatory agent capable of preventing immune system hypofunction. It is necessary to investigate the detailed mechanism to rule out any unforeseen effects of SPH in future research. PRACTICAL APPLICATIONS: Chemotherapy medications, despite their dominating detrimental effects of damaging immunological organs such as the spleen and thymus, extend the treatment process as well as the destruction of the self-immune system. This study found that SPH is an effective immunomodulatory agent capable of avoiding immune organ hypofunction and improving cell mediate immunity by enhancing macrophage activation, phagocytosis, spleenocyte proliferation, suppressing apoptosis, and elevating cytokines and antibodies. As a result, SPH can be utilized as a nutritional and functional dietary supplement to boost immunological modulation in combination with chemotherapy medications in order to lessen their adverse effects.

Industrially Produced Rice Protein Ameliorates Dextran Sulfate Sodium-Induced Colitis via Protecting the Intestinal Barrier, Mitigating Oxidative Stress, and Regulating Gut Microbiota

Inflammatory bowel disease (IBD) poses a threat to health and compromises the immune system and gut microflora. The present study aimed to explore the effects of rice protein (RP) purified from rice dregs (RD) on acute colitis induced by dextran sulfate sodium (DSS) and the underlying mechanisms. Results showed that RP treatment could alleviate the loss of body weight, colon shortening and injury, and the level of disease activity index, repair colonic function (claudin-1, ZO-1 and occludin), regulate inflammatory factors, and restore oxidative balance (malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), and total antioxidant capability (T-AOC)) in mice. Also, RP treatment could activate the Kelch-like ECH-associating protein 1 (Keap1)-nuclear factor E2-related factor 2 (Nrf2) signaling pathway, mediate the expression of downstream antioxidant protease (NQO-1, HO-1, and Gclc), regulate gut microbiota by enhancing the relative abundance of Akkermansia and increasing the value of F/B, and adjust short-chain fatty acid levels to alleviate DSS-induced colitis in mice. Thus, RP may be an effective therapeutic dietary resource for ulcerative colitis.

Immunomodulatory peptides-A promising source for novel functional food production and drug discovery

Immunomodulatory peptides are a complex class of bioactive peptides that encompasses substances with different mechanisms of action. Immunomodulatory peptides could also be used in vaccines as adjuvants which would be extremely desirable, especially in response to pandemics. Thus, immunomodulatory peptides in food of plant origin could be regarded both as valuable suplements of novel functional food preparation and/or as precursors or possible active ingredients for drugs design for treatment variety of conditions arising from impaired function of immune system. Given variety of mechanisms, different tests are required to assess effects of immunomodulatory peptides. Some of those effects show good correlation with in vivo results but others, less so. Certain plant peptides, such as defensins, show both immunomodulatory and antimicrobial effect, which makes them interesting candidates for preparation of functional food and feed, as well as templates for design of synthetic peptides.

Plant Protein-Based Delivery Systems: An Emerging Approach for Increasing the Efficacy of Lipophilic Bioactive Compounds

The development of plant protein-based delivery systems to protect and control lipophilic bioactive compound delivery (such as vitamins, polyphenols, carotenoids, polyunsaturated fatty acids) has increased interest in food, nutraceutical, and pharmaceutical fields. The quite significant ascension of plant proteins from legumes, oil/edible seeds, nuts, tuber, and cereals is motivated by their eco-friendly, sustainable, and healthy profile compared with other sources. However, many challenges need to be overcome before their widespread use as raw material for carriers. Thus, modification approaches have been used to improve their techno-functionality and address their limitations, aiming to produce a new generation of plant-based carriers (hydrogels, emulsions, self-assembled structures, films). This paper addresses the advantages and challenges of using plant proteins and the effects of modification methods on their nutritional quality, bioactivity, and techno-functionalities. Furthermore, we review the recent progress in designing plant protein-based delivery systems, their main applications as carriers for lipophilic bioactive compounds, and the contribution of protein-bioactive compound interactions to the dynamics and structure of delivery systems. Expressive advances have been made in the plant protein area; however, new extraction/purification technologies and protein sources need to be found Their functional properties must also be deeply studied for the rational development of effective delivery platforms.