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

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.

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.

Identification a novel Ganoderma FIP gene from Ganoderma capense and its functional expression in Pichia pastoris

Ganoderma capense is a precious medicinal fungus in China. In this study, a novel fungal immunomodulatory protein gene, named as FIP-gca, was cloned from G. capense by homologous cloning. Sequencing analysis indicated that FIP-gca was composed of 336 bp, which encoded a polypeptide of 110 amino acids. Protein sequence blasting and phylogenetic analysis showed that FIP-gca shared homology with other Ganoderma FIPs. FIP-gca was effectively expressed in Pichia pastoris GS115 at an expression level of 166.8 mg/L and purified using HisTrap™ fast-flow prepack columns. The immunomodulation capacity of rFIP-gca was demonstrated by that rFIP-gca could obviously stimulate cell proliferation and increase IL-2 secretion of murine spleen lymphocytes. Besides, antitumor activity of rFIP-gca towards human stomach cancer AGS cell line was evaluated in vitro. Cell wound scratch assay proved that rFIP-gca could inhibit migration of AGS cells. And flow cytometry assay revealed that rFIP-gca could significantly induce apoptosis of AGS cells. rFIP-gca was able to induce 18.12% and 22.29% cell apoptosis at 0.3 μM and 0.6 μM, respectively. Conclusively, the novel FIP-gca gene from G. capense has been functionally expressed in Pichia and rFIP-gca exhibited ideal immunomodulation and anti-tumour activities, which implies its potential application and study in future.

Size-controllable food-grade nanoparticles based on sea cucumber polypeptide with good anti-oxidative capacity to prolong lifespan in tumor-bearing mice

Liver cancer, a malignancy with a rising global incidence, poses a significant challenge in achieving effective treatment outcomes. As food-derived nutrient, sea cucumber peptide (SCP) has shown promising anticancer effects. Therefore, we explored the nanodelivery systems to encapsulate SCP to enhance its stability in the gastrointestinal tract and improve absorption within the tumor microenvironment. This study aimed to develop size-controllable multifunctional nanoparticles using SCP, procyanidins (PCs), and vanillin through molecular assembly via a one-pot Mannich condensation approach. These food-grade nanoparticles demonstrated water solubility and exhibited a spherical structure with sizes ranging from 441 to 1360 nm, depending on the concentration of the reactants. In vitro cell experiments demonstrated that SCP nanoparticles modified with PCs effectively reduced the generation of reactive oxygen species from H2O2 and acrylamide while maintaining normal levels of mitochondrial membrane potential. Furthermore, in vivo nutrition intervention studies conducted on tumor-bearing mice revealed that mice treated with SCP nanoparticles exhibited a survival rate of 40 %, which was significantly higher than the 0 % and 20 % survival rates observed in the control and SCP-treated groups, respectively. These findings suggest that SCP nanoparticles, possessing antioxidative properties and controllable sizes, hold potential for precision nutrition in the field of cancer treatment.

Purification and characterization of a novel immunoregulatory peptide from Sipunculus nudus L. protein

This study aimed to purify and characterize immunoregulatory peptides from Sipunculus nudus L. and to explore the underlying mechanisms. Ultrafiltration, gel filtration chromatography, and reverse phase high-performance liquid chromatography (RP-HPLC) were used to purify the peptide following enzymatic hydrolysis. Rates of lymphocyte proliferation and phagocytosis as well as nitric oxide (NO) production levels were used as indicators of immunoregulatory activity to screen the fractions. The amino acid sequence of the peptide, designated as SNLP, was identified as Arg-Val-Lys-Gly-Lys-Ile-Leu-Ala-Lys-Arg-Leu-Asn (RVKGKILAKRLN) by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Treatment with the synthetic SNLP increased the proliferation and phagocytosis of RAW 264.7 macrophages and promoted the secretion of tumor necrosis factor-ɑ (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β), and NO levels. The mRNA levels of these cytokines and iNOS were also increased by SNLP. Our results provide preliminary evidence suggesting that SNLP acts as a dual immunomodulatory peptide with immunostimulatory and anti-inflammatory activities. In summary, SNLP derived from Sipunculus nudus L. is a potent immunoregulatory peptide and represents a potential functional food or immunoregulatory drug.

Identification and Validation of Active Ingredient in Cerebrotein Hydrolysate-I Based on Pharmacokinetic and Pharmacodynamic Studies

Cerebrotein hydrolysate-1 (CH-1), a mixture of small peptides, polypeptides, and various amino acids derived from porcine brain, has been widely used in the treatment of cerebral injury. However, the bioactive composition and pharmacokinetics of CH-1 are still unexplored because of their complicated composition and relatively tiny amounts in vivo. Herein, NanoLC Orbitrap Fusion Lumos Tribrid Mass Spectrometer was firstly used to qualitatively analyze the components of CH-1. A total of 1347 peptides were identified, of which 43 peptides were characterized by high mass spectrometry (MS) intensity and identification accuracy. We then innovatively synthesized four main peptides for activity verification, and the results suggested that Pep72 (NYEPPTVVPGGDL) had the strongest neuroprotective effect on both in vivo and in vitro models. Next, a quantitative method for Pep72 was established based on liquid chromatography tandem mass spectrometry (LC-MS/MS) with the aid of Skyline software and then used in its pharmacokinetic studies. The results revealed that Pep72 had a high elimination rate and low exposure in rats. In addition, a hCMEC/D3-based in vitro model was built and firstly used to investigate the transport of Pep72. We found that Pep72 had extremely low blood-brain barrier permeability and was not a substrate of efflux transporters. The biotransformation of Pep72 in rat fresh plasma and tissues was investigated to explore the contradiction between pharmacokinetics and efficacy. A total of 11 main metabolites were structurally identified, with PGGDL and EPPTVPGGDL being the main metabolites of Pep72. Notably, metalloproteinase and cysteine protease were confirmed to be the main enzymes mediating Pep72 metabolism in rat tissues. SIGNIFICANCE STATEMENT: The NanoLC Orbitrap Fusion Lumos Tribrid Mass Spectrometer was firstly applied to discover the components of CH-1, and one main peptide Pep72 (NYEPPTVVPGGDL) was innovatively synthesized and firstly found to have the strongest neuroprotective effect among 1347 peptides identified from CH-1. Our study is the first time to identify and verify the active ingredient of CH-1 from the perspective of pharmacokinetics and pharmacodynamics, and provides a systematic technical platforms and strategies for the active substance research of other protein hydrolysates.

An update on the effects of food-derived active peptides on the intestinal microecology

The intestinal microecology is a research hotspot, and neologisms related to the gut such as gut-brain axis, gut-lung axis, gut-bone axis, gut-skin axis, gut-renal axis, and gut-liver axis have emerged from recent research. Meticulous investigation has discovered that food-derived active peptides (FDAPs) are bioactive substances that optimize the structure of the gut microbiota to improve human health. However, few reviews have summarized and emphasized the nutritional value of FDAPs and their mechanisms of action in regulating the composition of the gut microbiota. We aim to provide an update on the latest research on FDAPs by comparing, summarizing, and discussing the potential food sources of FDAPs, their physiological functions, and regulatory effects on the intestinal microecology. The key findings are that few studies have analyzed the potential mechanisms and molecular pathways through which FDAPs maintain intestinal microecological homeostasis. We found that an imbalance in the ratio of Bacteroidetes and Firmicutes in the gut microbiota and abnormal production of short-chain fatty acids are key to the occurrence and development of various diseases. This review provides theoretical support for future comprehensive research on the digestion, distribution, metabolism, and excretion of FDAPs and the mechanisms underlying the interactions between FDAPs and the intestinal microecology.

Extraction, Enzymatic Modification, and Anti-Cancer Potential of an Alternative Plant-Based Protein from Wolffia globosa

The global plant-based protein demand is rapidly expanding in line with the increase in the world's population. In this study, ultrasonic-assisted extraction (UAE) was applied to extract protein from Wolffia globosa as an alternative source. Enzymatic hydrolysis was used to modify the protein properties for extended use as a functional ingredient. The successful optimal conditions for protein extraction included a liquid to solid ratio of 30 mL/g, 25 min of extraction time, and a 78% sonication amplitude, providing a higher protein extraction yield than alkaline extraction by about 2.17-fold. The derived protein was rich in essential amino acids, including leucine, valine, and phenylalanine. Protamex and Alcalase were used to prepare protein hydrolysates with different degrees of hydrolysis, producing protein fragments with molecular weights ranging between <10 and 61.5 kDa. Enzymatic hydrolysis caused the secondary structural transformations of proteins from β-sheets and random coils to α-helix and β-turn structures. Moreover, it influenced the protein functional properties, particularly enhancing the protein solubility and emulsifying activity. Partial hydrolysis (DH3%) improved the foaming properties of proteins; meanwhile, an excess hydrolysis degree reduced the emulsifying stability and oil-binding capacity. The produced protein hydrolysates showed potential as anti-cancer peptides on human ovarian cancer cell lines.

The beneficial potential of protein hydrolysates as prebiotic for probiotics and its biological activity: a review

Probiotics are not only a food supplement, but they have shown great potential in their nutritional, health and therapeutic effects. To maximize the beneficial effects of probiotics, it is commonly achieved by adding prebiotics. Prebiotics primarily comprise indigestible carbohydrates, specific peptides, proteins, and lipids, with oligosaccharides being the most extensively studied prebiotics. However, these rapidly fermenting oligosaccharides have many drawbacks and can cause diarrhea and flatulence in the body. Hence, the exploration of new prebiotic is of great interest. Besides oligosaccharides, protein hydrolysates have been demonstrated to enhance the expression of beneficial properties of probiotics. Consequently, this paper outlines the mechanism underlying the action of protein hydrolysates on probiotics, as well as the advantageous impacts of proteins hydrolysates derived from various food sources on probiotics. In addition, this paper also reviews the currently reported biological activities of protein hydrolysates. The aim is a theoretical basis for the development and implementation of novel prebiotics.

Biohybrid magnetic microrobots: An intriguing and promising platform in biomedicine

Biohybrid magnetic microrobots (BMMs) have emerged as an exciting class of microrobots and have been considered as a promising platform in biomedicine. Many microorganisms and body's own cells show intriguing properties, such as morphological characteristics, biosafety, and taxis abilities (e.g., chemotaxis, aerotaxis), which have made them attractive for the fabrication of microrobots. For remote controllability and sustainable actuation, magnetic components are usually incorporated onto these biological entities, and other functionalized non-biological components (e.g., therapeutic agents) are also included for specific applications. This review highlights the latest developments in BMMs with a focus on their biomedical applications. It starts by introducing the fundamental understanding of the propulsion system at the microscale in a magnetically driven manner, followed by a summary of diverse BMMs based on different microorganisms and body's own cells along with their relevant applications. Finally, the review discusses how BMMs contribute to the advancements of microrobots, the current challenges of using BMMs in practical clinical settings, and the future perspectives of this exciting field. STATEMENT OF SIGNIFICANCE: Biohybrid magnetic microrobots (BMMs), composed of biological entities and functional parts, hold great potential and serve as a novel and promising platform for biomedical applications such as targeted drug delivery. This review comprehensively summarizes the recent advancements in BMMs for biomedical applications, mainly focused on the representative propulsion modalities in a magnetically propelled manner and diverse designs of BMMs based on different biological entities, including microorganisms and body's own cells. We hope this review can provide ideas for the future design, development, and innovation of micro/nanorobots in the field of biomedicine.

Oyster-derived dipeptides RI, IR, and VR promote testosterone synthesis by reducing oxidative stress in TM3 cells

Short peptides have gained widespread utilization as functional constituents in the development of functional foods due to their remarkable biological activity. Previous investigations have established the positive influence of oysters on testosterone biosynthesis, although the underlying mechanism remains elusive. This study aims to assess the impact of three dipeptides derived from oysters on the oxidative stress state of TM3 cells induced by AAPH while concurrently examining alterations in cellular testosterone biosynthesis capacity. The investigation encompasses an analysis of reactive oxygen species (ROS) content, antioxidant enzyme activity, apoptotic status, and expression levels of crucial enzymes involved in the testosterone synthesis pathway within TM3 cells, thus evaluating the physiological activity of the three dipeptides. Additionally, molecular docking was employed to investigate the inhibitory activity of the three dipeptides against ACE. The outcomes of this study imply that the oxidative stress state of cells impedes the synthesis of testosterone by inhibiting the expression of essential proteins in the testosterone synthesis pathway. These three dipeptides derived from oysters ameliorate cellular oxidative stress by directly scavenging excess ROS or reducing ROS production rather than enhancing cellular antioxidant capacity through modulation of antioxidant enzyme activity. These findings introduce a novel avenue for developing and utilizing antioxidant peptides derived from food sources.

Identification of a Novel Bioactive Peptide Derived from Frozen Chicken Breast Hydrolysate and the Utilization of Hydrolysates as Biopreservatives

Frozen chicken breast was hydrolyzed by treatment with thermolysin enzyme to obtain a chicken hydrolysate containing bioactive peptides. After that, a peptide was purified from the chicken hydrolysate utilizing a Sep-Pak C18 cartridge and reversed-phase high-performance liquid chromatography (RP-HPLC). The molecular weight of the chicken peptide was 2766.8. Protein sequence analysis showed that the peptide was composed of 25 amino acid residues. The peptide, designated as C25, demonstrated an inhibitory action on the angiotensin-converting enzyme (ACE) with a half maximal inhibitory concentration (IC50) value of 1.11 µg/mL. Interestingly, C25 showed antimicrobial activity against multi-drug resistant bacteria Proteus vulgaris F24B and Escherichia coli JM109, both with MIC values of 24 µg/mL. The chicken hydrolysate showed antioxidant activity with an IC50 value of 348.67 µg/mL. Furthermore, the proliferation of aerobic bacteria and Enterobacteriaceae as well as lipid oxidation were significantly reduced when the chicken hydrolysate was used as a natural preservative during cold storage of chicken breasts. Hydrolysates derived from muscle sources have the potential to be used in formulated food products and to contribute positively to human health.

Bioactive Peptides from Edible Mushrooms-The Preparation, Mechanisms, Structure-Activity Relationships and Prospects

Mushroom bioactive peptides (MBPs) are bioactive peptides extracted directly or indirectly from edible mushrooms. MBPs are known to have antioxidant, anti-aging, antibacterial, anti-inflammatory and anti-hypertensive properties, and facilitate memory and cognitive improvement, antitumour and anti-diabetes activities, and cholesterol reduction. MBPs exert antioxidant and anti-inflammatory effects by regulating the MAPK, Keap1-Nrf2-ARE, NF-κB and TNF pathways. In addition, MBPs exert antibacterial, anti-tumour and anti-inflammatory effects by stimulating the proliferation of macrophages. The bioactivities of MBPs are closely related to their molecular weights, charge, amino acid compositions and amino acid sequences. Compared with animal-derived peptides, MBPs are ideal raw materials for healthy and functional products with the advantages of their abundance of resources, safety, low price, and easy-to-achieve large-scale production of valuable nutrients for health maintenance and disease prevention. In this review, the preparation, bioactivities, mechanisms and structure-activity relationships of MBPs were described. The main challenges and prospects of their application in functional products were also discussed. This review aimed to provide a comprehensive perspective of MBPs.

Prospecting native and analogous peptides with anti-SARS-CoV-2 potential derived from the trypsin inhibitor purified from tamarind seeds

The study aimed to prospect in silico native and analogous peptides with anti-SARS-CoV-2 potential derived from the trypsin inhibitor purified from tamarind seeds (TTIp). From the most stable theoretical model of TTIp (TTIp 56/287), in silico cleavage was performed for the theoretical identification of native peptides and generation of analogous peptides. The anti-SARS-CoV-2 potential was investigated through molecular dynamics (MD) simulation between the peptides and binding sites of transmembrane serine protease 2 (TMPRSS2), responsible for the entry of SARS-CoV-2 into the host cell. Five native and analogous peptides were obtained and validated through chemical and physical parameters. The best interaction potential energy (IPE) occurred between TMPRSS2 and one of the native peptides obtained by cleavage with trypsin and its analogous peptide. Thus, both peptides showed many hydrophobic residues, a common physical-chemical property among the peptides that inhibit the entry of enveloped viruses, such as SARS-CoV-2, present in specific drugs to treat COVID-19.

Immune Enhancement of Clam Peptides on Immunosuppressed Mice Induced by Hydrocortisone

Clam peptides, marine-derived biological peptides, have been broadly investigated and applied as health foods, among which immunomodulation is one of their biological activities that cannot be ignored in vivo. In this study, we concentrated on exploring the effects of Ruditapes philippinarum peptides (RPPs) on immunomodulation and the balance of intestinal microbiota in hydrocortisone (HC)-induced immunosuppressed mice. The results revealed that RPPs could increase the thymus and spleen indices and number of white blood cells, promote the secretion level of cytokines (IL-2, IL-6, TNF-α, and INF-γ), repair the morphology of the spleen and thymus, and enhance the proliferation of T-lymphocyte subsets in immunosuppressed mice. Moreover, RPPs improved the abundance of beneficial bacteria and preserved the ecological equilibrium of the gut microbiota. In conclusion, RPPs have significant immunomodulatory effects on immunosuppressed mice and may be developed as immunomodulators or immune adjuvants in functional foods and drugs; they are also beneficial to the utilization of the high value of marine shellfish.

RNA-seq analysis reveals an immunomodulatory peptide from highland barley activating RAW264.7 macrophages via TNF/NF-κB signaling pathway

Highland barley (HB) is an important cereal crop distributed in the plateau region. Bioactive peptides (BAPs) derived from cereal proteins have shown biological functions. However, the knowledge of highland barley peptide (HBP) is limited. This study aims to explore the immunomodulatory activity of HBP and the relationship between immunomodulatory activity and related gene expression through RNA-seq. Firstly, HBP is isolated from protease hydrolysates of HB protein, yielding 12.04% of crude HB protein. The molecular weight of HBP is about 1702 Da analyzed by gel filtration chromatography, and HBP has a specific amino acid sequence as Gln-Pro-Gln-Gln-Pro-Phe-Pro-Gln (QPQPFPQ) analyzed by LC-MS. Besides, HBP contains 42.20% hydrophobic amino acids and 10.86% basic amino acids. Next, the immunomodulatory activity of HBP in vitro shows that HBP enhances the phagocytosis of RAW264.7 macrophages, promotes nitric oxide (NO) production and the mRNA expression of pro-inflammatory genes including tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), and inducible nitric oxide synthase (iNOS), and decreases the mRNA expression of anti-inflammatory gene, transforming growth factor β1 (TGF-β1). RNA-seq analysis reveals TNF and nuclear factor kappa B (NF-κB) pathways are upregulated, and RT-qPCR is performed to verify RNA-seq analysis. In conclusion, HBP activates RAW264.7 macrophages via TNF/NF-κB signaling pathway. HBP, as a significant immunomodulatory peptide, might be a promising resource for future functional foods.

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.

Shifting archetype to nature's hidden gems: from sources, purification to uncover the nutritional potential of bioactive peptides

Contemporary scientific findings revealed that our daily food stuffs are enriched by encrypted bioactive peptides (BPs), evolved by peptide linkage of amino acids or encrypted from the native protein structures. Remarkable to these BPs lies in their potential health benefiting biological activities to serve as nutraceuticals or a lead addition to the development of functional foods. The biological activities of BPs vary depending on the sequence as well as amino acid composition. Existing database records approximately 3000 peptide sequences which possess potential biological activities such as antioxidants, antihypertensive, antithrombotic, anti-adipogenics, anti-microbials, anti-inflammatory, and anti-cancerous. The growing evidences suggest that BPs have very low toxicity, higher accuracy, less tissue accretion, and are easily degraded in the disposed environment. BPs are nowadays evolved as biologically active molecules with potential scope to reduce microbial contamination as well as ward off oxidation of foods, amend diverse range of human diseases to enhance the overall quality of human life. Against the clinical and health perspectives of BPs, this review aimed to elaborate current evolution of nutritional potential of BPs, studies pertaining to overcome limitations with respect to special focus on emerging extraction, protection and delivery tools of BPs. In addition, the nano-delivery mechanism of BP and its clinical significance is detailed. The aim of current review is to augment the research in the field of BPs production, identification, characterisation and to speed up the investigation of the incredible potentials of BPs as potential nutritional and functional food ingredient.

Post-COVID-19 Anosmia and Therapies: Stay Tuned for New Drugs to Sniff Out

Background: Anosmia is defined as the complete absence of olfactory function, which can be caused by a variety of causes, with upper respiratory tract infections being among the most frequent causes. Anosmia due to SARS-CoV-2 infection has attracted attention given its main role in symptomatology and the social impact of the pandemic. Methods: We conducted systematic research in a clinicaltrials.gov database to evaluate all active clinical trials worldwide regarding drug therapies in adult patients for anosmia following SARS-CoV-2 infection with the intention of identifying the nearby prospects to treat Anosmia. We use the following search terms: "Anosmia" AND "COVID-19" OR "SARS-CoV-2" OR "2019 novel coronavirus". Results: We found 18 active clinical trials that met our criteria: one phase 1, one phase 1-2, five phases 2, two phases 2-3, three phases 3, and six phases 4 studies were identified. The drug therapies that appear more effective and promising are PEA-LUT and Cerebrolysin. The other interesting drugs are 13-cis-retinoic acid plus aerosolized Vitamin D, dexamethasone, and corticosteroid nasal irrigation. Conclusions: COVID-19 has allowed us to highlight how much anosmia is an important and debilitating symptom for patients and, above all, to direct research to find a therapy aimed at curing the symptom, whether it derives from SARS-CoV-2 infection or other infections of the upper airways. Some of these therapies are very promising and are almost at the end of experimentation. They also provide hope in this field, which not addressed until recently.

Investigation of the optimal production conditions for egg white hydrolysates and physicochemical characteristics

This study aimed to investigate the potential of egg white protein hydrolysate (EWH) as a functional food by identifying the optimum production conditions for EWH with response surface methodology (the results of the sensory evaluation were considered as an essential quality indicator). At the same time, its physicochemical and biological activity was also evaluated. The optimal economic production conditions were selected: substrate concentration of 12.5%, enzyme content of 7.5%, and hydrolysis time at 100 min. The degree of hydrolysis (DH %) was 13.51%. In addition, to the better acceptance of the evaluation, it also helps to reduce the production cost of the protein hydrolysate, which is beneficial to future processing and applications. The antioxidant capacity experiments showed that EWH has good antioxidant activity, which presents a dose-dependent relationship. Hence, this study provides a theoretical basis for future research and application of EWH for processing applications, including dietary supplementation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05708-0.

A fast stop-flow two-dimensional liquid chromatography tandem mass spectrometry and its application in food-derived protein hydrolysates

Food-derived bioactive peptides have many outstanding features like high safety, easy absorption, etc. However, explorations of the peptides are suffering from the limited knowledge of sample composition and low efficiency of separation techniques. In this work, a fast stop-flow two-dimensional liquid chromatography tandem mass spectrometry (2DLC-MS) was designed and constructed in-house. For chromatographic system optimization, the effects of column pairs and fraction transfer volumes on separation performance were studied. The pair of Protein BEH SEC and HSS T3 columns was found of high orthogonality. The peak capacity detected by the optimized 2DLC reached 1165 (for corn protein hydrolysates), indicating high resolving power. Moreover, the number of peptides identified from corn, soybean and casein protein hydrolysates reached as high as 8330, 8925 and 7215, respectively, demonstrating the high potential of the system. This would help reveal the peptide composition and facilitate the research on exploring bioactive peptides from food-derived protein hydrolysates.

Sea Cucumber Hydrolysate Alleviates Immunosuppression and Gut Microbiota Imbalance Induced by Cyclophosphamide in Balb/c Mice through the NF-κB Pathway

This study aimed to investigate the effect of sea cucumber hydrolysate (SCH) on immunosuppressed mice induced by cyclophosphamide (Cy). Our findings demonstrated that SCH could increase the thymus index and spleen index, decrease the serum alanine transaminase (ALT) and aspartate aminotransferase (AST) levels, increase the serum IgG and small intestinal sIgA levels, reduce small intestinal and colon tissue damage, and activate the nuclear factor-κB (NF-κB) pathway by increasing TRAF6 and IRAK1 protein levels, as well as the phosphorylation levels of IκBα and p65, thereby enhancing immunity. In addition, SCH alleviated the imbalance of the gut microbiota by altering the composition of the gut microbiota in immunosuppressed mice. At the genus level, when compared with the model group, the relative abundance of Dubosiella, Lachnospiraceae, and Ligilactobacillus increased, while that of Lactobacillus, Bacteroides, and Turicibacter decreased in the SCH groups. Moreover, 26 potential bioactive peptides were identified by oligopeptide sequencing and bioactivity prediction. This study's findings thus provide an experimental basis for further development of SCH as a nutritional supplement to alleviate immunosuppression induced by Cy as well as provides a new idea for alleviating intestinal damage induced by Cy.

The Beneficial Effects of Soybean Proteins and Peptides on Chronic Diseases

With lifestyle changes, chronic diseases have become a public health problem worldwide, causing a huge burden on the global economy. Risk factors associated with chronic diseases mainly include abdominal obesity, insulin resistance, hypertension, dyslipidemia, elevated triglycerides, cancer, and other characteristics. Plant-sourced proteins have received more and more attention in the treatment and prevention of chronic diseases in recent years. Soybean is a low-cost, high-quality protein resource that contains 40% protein. Soybean peptides have been widely studied in the regulation of chronic diseases. In this review, the structure, function, absorption, and metabolism of soybean peptides are introduced briefly. The regulatory effects of soybean peptides on a few main chronic diseases were also reviewed, including obesity, diabetes mellitus, cardiovascular diseases (CVD), and cancer. We also addressed the shortcomings of functional research on soybean proteins and peptides in chronic diseases and the possible directions in the future.

Physicochemical, Microbiological, and Sensory Properties of Set-Type Yoghurt Supplemented with Camel Casein Hydrolysate

The microbiological, rheological, and sensory properties of set-type yoghurt were investigated in the presence of camel and cow casein hydrolysates produced by the action of trypsin enzymes. The hydrolysates significantly decreased the fermentation and coagulation time of the yoghurt production. The rate of pH decrease was significantly (p < 0.05) higher in samples treated with cow casein hydrolysate in comparison with control samples. Compared with the control, the cell growth of the yoghurt culture increased with the supplementation of the casein hydrolysate. Moreover, the survival of lactic acid bacteria (LAB) was enhanced by the addition of hydrolysates. The fortification of cow milk with camel and cow casein hydrolysates contributed to a significant improvement of the rheological and sensory properties of yoghurt. In conclusion, camel and cow casein hydrolysate could be used as a supplement in set-type yoghurt production with a potential beneficial effect on fermentation time, survival of total bacterial count, and overall acceptability.

3D high-precision melt electro written polycaprolactone modified with yeast derived peptides for wound healing

In this study melt electro written (MEW) scaffolds of poly(ε-caprolactone) PCL are decorated with anti-inflammatory yeast-derived peptide for skin wound healing. Initially, 13 different yeast-derived peptides were screened and analyzed using both in vitro and in vivo assays. The MEW scaffolds are functionalized with the selected peptide VLSTSFPPW (VW-9) with the highest activity in reducing pro-inflammatory cytokines and stimulating fibroblast proliferation, migration, and collagen production. The peptide was conjugated to the MEW scaffolds using carbodiimide (CDI) and thiol chemistry, with and without plasma treatment, as well as by directly mixing the peptide with the polymer before printing. The MEW scaffolds modified using CDI and thiol chemistry with plasma treatment showed improved fibroblast and macrophage penetration and adhesion, as well as increased cell proliferation and superior anti-inflammatory properties, compared to the other groups. When applied to full-thickness excisional wounds in rats, the peptide-modified MEW scaffold significantly enhanced the healing process compared to controls (p < 0.05). This study provides proof of concept for using yeast-derived peptides to functionalize biomaterials for skin wound healing.

Proteins and their functionalization for finding therapeutic avenues in cancer: Current status and future prospective

Despite the remarkable advancement in the health care sector, cancer remains the second most fatal disease globally. The existing conventional cancer treatments primarily include chemotherapy, which has been associated with little to severe side effects, and radiotherapy, which is usually expensive. To overcome these problems, target-specific nanocarriers have been explored for delivering chemo drugs. However, recent reports on using a few proteins having anticancer activity and further use of them as drug carriers have generated tremendous attention for furthering the research towards cancer therapy. Biomolecules, especially proteins, have emerged as suitable alternatives in cancer treatment due to multiple favourable properties including biocompatibility, biodegradability, and structural flexibility for easy surface functionalization. Several in vitro and in vivo studies have reported that various proteins derived from animal, plant, and bacterial species, demonstrated strong cytotoxic and antiproliferative properties against malignant cells in native and their different structural conformations. Moreover, surface tunable properties of these proteins help to bind a range of anticancer drugs and target ligands, thus making them efficient delivery agents in cancer therapy. Here, we discuss various proteins obtained from common exogenous sources and how they transform into effective anticancer agents. We also comprehensively discuss the tumor-killing mechanisms of different dietary proteins such as bovine α-lactalbumin, hen egg-white lysozyme, and their conjugates. We also articulate how protein nanostructures can be used as carriers for delivering cancer drugs and theranostics, and strategies to be adopted for improving their in vivo delivery and targeting. We further discuss the FDA-approved protein-based anticancer formulations along with those in different phases of clinical trials.

Brown goat yogurt: Metabolomics, peptidomics, and sensory changes during production

Brown goat milk products have gained popularity for their unique taste and flavor. The emergence of chain-reversal phenomenon makes the design and development of goat milk products gradually tend to a consumer-oriented model. However, the precise mechanism of how browning and fermentation process causes characteristics is not clear. In an effort to understand how the treatments potentially lead to certain metabolite profile changes in goat milk, comprehensive, quantitative metabolomics and peptidomics analysis of goat milk samples after browning and fermentation were undertaken. An intelligent hybrid z-score standardization-principal components algorithm-multimodal denoizing autoencoder was used for feature fusion and hidden layer fusion in high-dimensional variable space. The fermentation process significantly improved the flavor of brown goat yogurt through the tricarboxylic acid-urea-glycolysis composite pathway. Bitter peptides HPFLEWAR, PPGLPDKY, and PPPPPKK have strong interactions with both putative dipeptidyl peptidase IV and angiotensin-converting enzyme, proving that brown goat yogurt can be considered as effective provider of potential putative dipeptidyl peptidase IV and angiotensin-converting enzyme inhibitors. The level of health-promoting bioactive components and sensory contributed to consumer selection. The proposed multimodal data integrative analysis platform was applicable to explain the effect of the dynamic changes of metabolites and peptides on consumer preferences.

A critical review on immunomodulatory peptides from plant sources; action mechanisms and recent advances

Plant protein components contribute positively to human well-being as they modulate the immune status of a consumer, especially when the enzymatic method is employed in order to release their bioactive peptides. These peptides are derived from plant-based foods such as soy, wheat, barley, rye, oats, rice, corn, sorghum, and millet, the famous staple foods around the world. Since these peptides are crucial to functional food among other key industries, the present study endeavored to scout for relevant information within the past three decades, using the Web of Science, Scopus, and Google search engines. In this review, first, the core of immunomodulation and types of immunomodulatory agents will be discussed, followed by the production of plant-based immunomodulatory peptides and their immunomodulatory mechanisms in cells, animals, and humans are also studied. Finally, applications and challenges associated with plant-based immunomodulatory peptides are put forward.

Research progress in lipid metabolic regulation of bioactive peptides

Hyperlipidemia poses a serious threat to human health and evaluating the ability of natural active substances to regulate disorders of lipid metabolism is the focus of food functionality research in recent years. Bioactive peptides are distinguished by their broad range of sources, high nutritional content, ease of absorption and use by the body, and ease of determining their sequences. Bioactive peptides have a wide range of potential applications in the area of medicines and food. The regulation of lipid metabolism disorder caused by bioactive peptides from different sources provides a reference for the development and research of bioactive peptides for lipid reduction.

Graphical Abstract

The Cytokines-Directed Roles of Spirulina for Radioprotection of Lacrimal Gland

PURPOSE

To evaluate the radioprotective effect of spirulina (SP) on the lacrimal glands after RAI treatment.

METHODS

A total of 30 rats were separated into control, RAI and SP group. The radioprotective effect of SP on lacrimal glands was evaluated with histopathological and cytopathological analysis. Lacrimal glands were analyzed for tumor necrosis factor alpha (TNF-α), interleukin-2 (IL-2), IL-4, IL-6, IL-10, nuclear factor-kappa B (NF-κB), total oxidant status (TOS) and total antioxidant capacity (TAC) levels.

RESULTS

RAI increased TNF-α (p = .001), IL-6 (p = .018), and NF-κB levels (p < .0005). Following the administration of SP, TNF-α (p < .0005), IL-4 (p = .026), and IL-6 (p = .006) levels decreased. RAI decreased the TAC levels (p = .001), and co-administration of SP increased the TAC level, but was not statistically significant. SP decreased the TOS level after RAI (p = .022)                .

CONCLUSIONS

SP protects lacrimal glands from RAI-induced damage.

Shellfish industrial waste reuse

The global production of aquatic organisms has grown steadily in recent decades. This increase in production results in high volumes of by-products and waste, generally considered to be of low commercial value and part of them are consequently discarded in landfills or in the sea, causing serious environmental problems when not used. Currently, a large part of the reused aquaculture waste is destined for the feed industry. This generally undervalued waste presents an important source of bioactive compounds in its composition, such as: amino acids, carotenoids, chitin and its derivatives, fatty acids and minerals. These compounds are capable of offering numerous benefits due to their bioactive properties. However, the applicability of these compounds may be opportune in several other sectors. This review describes studies that seek to obtain and apply bioactive compounds from different sources of aquaculture waste, thus adding commercial value to these underutilized biomasses.HIGHLIGHTSVolume of aquaculture industrial waste from crustaceans and mollusks.Quantity and quality of bioactive components in aquaculture waste.Applications of recovered proteins, lipids, chitin, carotenoids and minerals.Future prospects for the destination of aquaculture waste.

Bioactive protein hydrolysates obtained from amaranth by fermentation with lactic acid bacteria and Bacillus species

Protein hydrolysates are a promising source of bioactive peptides. One strategy by which they can be obtained is fermentation. This method uses the proteolytic system of microorganisms to hydrolyze the parental protein. Fermentation is a little-explored method for obtaining protein hydrolysates from amaranth. Different strains of lactic acid bacteria (LAB) and Bacillus species isolated from goat milk, broccoli, aguamiel, and amaranth flour were used in this work. First, the total protein degradation (%TPD) of amaranth demonstrated by the strains was determined. The results ranged from 0 to 95.95%, the strains that produced a higher %TPD were selected. These strains were identified by molecular biology and were found to correspond to the genera Enterococcus, Lactobacillus, Bacillus, and Leuconostoc. Fermentation was carried out with amaranth flour and the selected strains. After this process, water/salt extracts (WSE) containing the released protein hydrolysates were obtained from amaranth doughs. The peptide concentration was measured by the OPA method. The antioxidant, antihypertensive and antimicrobial activity of the WSE was evaluated. In the FRAP test, the best WSE was LR9 with a concentration of 1.99 μMTE/L ± 0.07. In ABTS, 18C6 obtained the highest concentration with 19.18 μMTE/L ± 0.96. In the DPPH test, there was no significant difference. In terms of antihypertensive activity, inhibition percentages ranging from 0 to 80.65% were obtained. Some WSE were found to have antimicrobial properties against Salmonella enterica and Listeria monocytogenes. Fermentation of amaranth with LAB and Bacillus spp. allowed the release of protein hydrolysates with antioxidant, antihypertensive, and antimicrobial activity.

Microbiology, flavor formation, and bioactivity of fermented soybean curd (furu): A review

Soybeans are an important plant-based food but its beany flavor and anti-nutritional factors limit its consumption. Fermentation is an effective way to improve its flavor and nutrition. Furu is a popular fermented soybean curd and mainly manufactured in Asia, which has been consumed for thousands of years as an appetizer because of its attractive flavors. This review first classifies furu products on the basis of various factors; then, the microorganisms involved in its fermentation and their various functions are discussed. The mechanisms for the formation of aroma and taste compounds during fermentation are also discussed; and the microbial metabolites and their bioactivities are analyzed. Finally, future prospects and challenges are introduced and further research is proposed. This information is needed to protect the regional characteristics of furu and to regulate its consistent quality. The current information suggests that more in vivo experiments and further clinical trials are needed to confirm its safety and the microbial community needs to be optimized and standardized for each type of furu to improve the production process.

Hemp Protein Hydrolysates Modulate Inflammasome-Related Genes in Microglial Cells

A prolonged inflammatory response can lead to the development of neurodegenerative diseases such as Alzheimer's disease. Enzymatic hydrolysis is a sustainable way to increase the value of protein sources by obtaining peptides that can exert bioactivity. Hemp (Cannabis sativa L.) protein hydrolysates have been proven to exert anti-inflammatory activity. In this study, two hemp protein hydrolysate (HPHs), obtained with Alcalase as sole catalyst, or with Alcalase followed by Flavourzyme, were evaluated as inflammatory mediators (TNFα, IL-1β, IL-6, and IL-10), microglial polarization markers (Ccr7, iNos, Arg1, and Ym1), and genes related to inflammasome activation (Nlrp3, Asc, Casp1, and Il18), employing the lipopolysaccharide (LPS)-induced neuroinflammation model in murine BV-2 microglial cells. A significant decrease of the expression of proinflammatory genes (e.g., Tnfα, Ccr7, inos, and Nlrp3, among others) and increase of the expression anti-inflammatory cytokines in microglial cells was observed after treatment with the test HPHs. This result in the cell model suggests a polarization toward an anti-inflammatory M2 phenotype. Our results show that the evaluated HPHs show potential neuroprotective activity in microglial cells via the inflammasome.

In Silico functional and phylogenetic analyses of fungal immunomodulatory proteins of some edible mushrooms

Mushrooms are a well known source of many bioactive and nutritional compounds with immense applicability in both the pharmaceutical and food industries. They are widely used to cure various kinds of ailments in traditional medicines. They have a low amount of fats and cholesterol and possess a high number of proteins. Immunomodulators have the ability which can improve immunity and act as defensive agents against pathogens. One such class of immunomodulators is fungal immunomodulatory proteins (FIPs). FIPs have potential roles in the treatment of cancer, and immunostimulatory effects and show anti-tumor activities. In the current study, 19 FIPs from edible mushrooms have been used for comparison and analysis of the conserved motifs. Phylogenetic analysis was also carried out using the FIPs. The conserved motif analysis revealed that some of the motifs strongly supported their identity as FIPs while some are novel. The fungal immunomodulatory proteins are important and have many properties which can be used for treating ailments and diseases and this preliminary study can be used for the identification and functional characterization of the proposed novel motifs and in unraveling the potential roles of FIPs for developing newer drugs.

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

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

Release of Bioactive Peptides from Erythrina edulis (Chachafruto) Proteins under Simulated Gastrointestinal Digestion

The estimated and concerning rise in world population over the next few years and the consequent increase in food demand will lead to a deterioration in global food security. To avoid or reduce this world crisis, informed and empowered consumers are turning to sustainable and nutrient-rich foods that substitute animal products, also reducing their associated environmental impact. Moreover, due to the demonstrated influence of diet on the risk of high incidence and mortality of noncommunicable diseases, the current established food pattern is focused on the consumption of foods that have functionality for health. Among these new foods, traditional and underutilized plants are gaining interest as alternative protein sources providing nutritional and biological properties. In this work, the potential of Erythrina edulis (chachafruto) proteins as a source of multifunctional peptides after transit through the gastrointestinal tract has been demonstrated, with antioxidant and immunostimulating effects in both biochemical assays and cell culture. While low molecular weight peptides released during the digestive process were found to be responsible for protection against oxidative stress mediated by their radical scavenging activity, high molecular weight peptides exerted immunostimulating effects by upregulation of immunoresponse-associated biomarkers. The findings of this study support the promising role of chachafruto proteins as a new antioxidant and immunostimulatory ingredient for functional foods and nutraceuticals.

Nutritional Composition, Health Benefits, and Application Value of Edible Insects: A Review

For thousands of years, edible insects have been used as food to alleviate hunger and improve malnutrition. Some insects have also been used as medicines because of their therapeutic properties. This is not only due to the high nutritional value of edible insects, but more importantly, the active substances from edible insects have a variety of biofunctional activities. In this paper, we described and summarized the nutritional composition of edible insects and discussed the biological functions of edible insects and their potential benefits for human health. A summary analysis of the findings for each active function confirms that edible insects have the potential to develop functional foods and medicines that are beneficial to humans. In addition, we analyzed the issues that need to be considered in the application of edible insects and the current status of edible insects in food and pharmaceutical applications. We concluded with a discussion of regulations related to edible insects and an outlook on future research and applications of edible insects. By analyzing the current state of research on edible insects, we aim to raise awareness of the use of edible insects to improve human health and thus promote their better use and development.

Ameliorative Effects of Oyster Protein Hydrolysates on Cadmium-Induced Hepatic Injury in Mice

Cadmium (Cd) is a widespread environmental toxicant that can cause severe hepatic injury. Oyster protein hydrolysates (OPs) have potential effects on preventing liver disease. In this study, thirty mice were randomly divided into five groups: the control, Cd, Cd + ethylenediaminetetraacetic acid (EDTA, 100 mg/kg), and low/high dose of OPs-treatment groups (100 mg/kg or 300 mg/kg). After continuous administration for 7 days, the ameliorative effect of OPs on Cd-induced acute hepatic injury in Cd-exposed mice was assessed. The results showed that OPs significantly improved the liver function profiles (serum ALT, AST, LDH, and ALP) in Cd-exposed mice. Histopathological analysis showed that OPs decreased apoptotic bodies, hemorrhage, lymphocyte accumulation, and inflammatory cell infiltration around central veins. OPs significantly retained the activities of SOD, CAT, and GSH-Px, and decreased the elevated hepatic MDA content in Cd-exposed mice. In addition, OPs exhibited a reductive effect on the inflammatory responses (IL-1β, IL-6, and TNF-α) and inhibitory effects on the expression of inflammation-related proteins (MIP-2 and COX-2) and the ERK/NF-κB signaling pathway. OPs suppressed the development of hepatocyte apoptosis (Bax, caspase-3, and Blc-2) and the activation of the PI3K/AKT signaling pathway in Cd-exposed mice. In conclusion, OPs ameliorated the Cd-induced hepatic injury by inhibiting oxidative damage and inflammatory responses, as well as the development of hepatocyte apoptosis via regulating the ERK/NF-κB and PI3K/AKT-related signaling pathways.

Purification and Identification of Peptides from Oyster (Crassostrea hongkongensis) Protein Enzymatic Hydrolysates and Their Anti-Skin Photoaging Effects on UVB-Irradiated HaCaT Cells

This study aimed to purify and identify antiphotoaging peptides from oyster (Crassostrea hongkongensis) protein enzymatic hydrolysates (OPEH) and to investigate the possible mechanism underlying its antiphotoaging effect. Multiple methods (Ultrafiltration, G25 Chromatography, RP-HPLC, and LC/MS/MS) had been used for this purpose, and eventually, two peptides, including WNLNP and RKNEVLGK, were identified. Particularly, WNLNP exerted remarkable antiphotoaging effect on the UVB-irradiated HaCaT photoaged cell model in a dose-dependent manner. WNLNP exerted its protective effect mainly through inhibiting ROS production, decreasing MMP-1 expression, but increasing extracellular pro-collagen I content. Furthermore, WNLNP downregulated p38, JNK, ERK, and p65 phosphorylation in the MAPK/NF-κB signaling pathway and attenuated bax over-expressions but reversed bcl-2 reduction in UVB- irradiated HaCaT cells. The molecular docking analysis showed that WNLNP forms five and seven hydrogen bonds with NF-κB (p65) and MMP-1, respectively. This study suggested that a pentapeptide WNLNP isolated from OPEH had great potential to prevent and regulate skin photoaging.