Search Results (936)

Medicinal plants and animal-derived proteins represent valuable natural sources of bioactive components with pharmaceutical potential. Whilst some medicinal plants and animal-derived proteins also offer rich sources of anticoagulant bioactive peptides, their development faces multiple challenges: anticoagulant evaluation relies on single-parameter assays with limited reliability, native proteins demonstrate suboptimal activity without enzymatic treatment, and few researchers investigate bioavailable peptides. Our study establishes an innovative framework using the leech as a case study to overcome these barriers. A novel anticoagulant evaluation model was first established with the Critic-G1 weighting method. And we optimized the enzymatically hydrolyzed extracts with high activity using Box–Behnken response surface methodology. Subsequently, the everted gut sac model was implemented to simulate intestinal absorption and screen for absorbable peptide fractions. Furthermore, peptidomics was employed to identify the bioactive peptides. Lastly, we identified the bioactivity using anticoagulation assays. Results indicated that the optimal hydrolysis conditions were achieved with trypsin at 50.48 °C, an enzyme-to-substrate ratio of 6.78%, 7.51 h, and pH of 8.06. The peptide DLRWM was identified through integrated peptidomics and molecular docking approaches, with subsequent activity validation demonstrating its potent anticoagulant effects. This study has successfully identified a novel anticoagulant peptide (DLRWM) with confirmed intestinal absorption properties and provides a template for unlocking the pharmaceutical potential of medicinal animal proteins. Full article

Type I collagen is a major protein in animals, and its hydrolyzed products, collagen peptides, have wide-ranging applications. This article reviews collagen peptides’ preparation methods, biological activities, and application progress in the fields of food, cosmetics, and medicine. By employing various extraction and hydrolysis methods, collagen peptides with different molecular weights can be obtained, and their biological activities are closely related to their molecular weight and amino acid sequence. Studies have revealed that collagen peptides possess a variety of biological activities, including antioxidant, hematopoietic promotion, osteogenic differentiation promotion, antihypertensive, and anti-diabetic effects. In the food industry, their antioxidant and hypoglycemic properties have opened new avenues for the development of healthy foods; in the cosmetics field, the moisturizing, anti-aging, and repair functions of collagen peptides are favored by consumers; in the medical field, collagen peptides are used in wound dressings, drug carriers, and tissue engineering scaffolds. Looking to the future, the development of green and efficient preparation technologies for collagen peptides and in-depth research into the relationship between their structure and function will be important research directions. The multifunctional properties of collagen peptides provide a broad prospect for their further application in the health industry. Full article

Soybean meal (SBM) is extensively used as a predominant protein source in animal feed. However, raw soybean cannot be directly utilized in animal feed, due to the presence of the Kunitz trypsin inhibitor (KTi) and the Bowman–Birk protease inhibitor (BBi). These antinutritional factors inhibit the digestive enzymes in animals, trypsin and chymotrypsin, resulting in poor animal performance. To inactivate the activity of protease inhibitors, SBM is subjected to heat processing, a procedure that can negatively impact the soybean protein quality. Thus, it would be beneficial to develop soybean varieties with little or no trypsin inhibitors. In this study, we report on the creation of experimental soybean lines with significantly reduced levels of Bowman–Birk protease inhibitors. RNA interference (RNAi) technology was employed to generate several transgenic soybean lines. Some of these BBi knockdown soybean lines showed significantly lower amounts of both trypsin and chymotrypsin inhibitor activities. Western blot analysis revealed the complete absence of BBi in selected RNAi-derived lines. RNA sequencing (RNAseq) analysis demonstrated a drastic reduction in the seed-specific expression of BBi genes in the transgenic soybean lines during seed development. Confocal fluorescence immunolabeling studies showed that the accumulation of BBi was drastically diminished in BBi knockdown lines compared to wild-type soybeans. The absence of BBi in the transgenic soybean did not alter the overall protein, oil, and sulfur amino acid content of the seeds compared to wild-type soybeans. The seed protein from the BBi knockdown lines were more rapidly hydrolyzed by trypsin and chymotrypsin compared to the wild type, indicating that the absence of BBi enhances protein digestibility. Our study suggests that these BBi knockdown lines could be a valuable resource in order for plant breeders to incorporate this trait into commercial soybean cultivars, potentially enabling the use of raw soybeans in animal feed. Full article

Arugula leaves (Diplotaxis tenuifolia L. and Eruca sativa L.) are a must-have ingredient in ready-to-eat salads, as they are prized for their appearance, taste, and flavor. The nutraceutical properties of this leafy vegetable are attributed to the presence of valuable secondary metabolites, such as phenolic acids and glucosinolates. Using UHPLC-Q-Orbitrap HRMS analysis and ion chromatography, we characterized the content of phenolic acids, glucosinolates, nitrates, and organic acids in organic arugula [Diplotaxis tenuifolia (L.) DC] and evaluated how the foliar application of three different non-microbial biostimulants (a seaweed extract, a vegetable protein hydrolysate, and a tropical plant extract) modulated the expression of these. Although the application of vegetable protein hydrolysate increased, compared to control plants, the nitrate content, the application of the same biostimulant increased the total content of glucosinolates and phenolic acid derivatives by 5.2 and 17.2%. Specifically, the foliar application of the plant-based biostimulant hydrolyzed protein significantly increased the content of glucoerucin (+22.9%), glucocheirolin (+76.8%), and ferulic acid (+94.1%). The highest values of flavonoid derivatives (173.03 μg g⁻¹ dw) were recorded from plants subjected to the exogenous application of seaweed extract. The results obtained underscore how biostimulants, depending on their origin and composition, can be exploited not only to improve agronomic performance but also to enhance the nutraceutical content of vegetables, guaranteeing end consumers a product with premium quality characteristics. Full article

Soybean flours are widely used as a protein-rich ingredient in fish aquafeeds, and to obtain value-added compounds after a previous treatment with proteases. Additionally, non-starch polysaccharidases (NSPases) enhance dietary protein bioaccessibility and have been used as feed additives. In this study, defatted soybean flour was hydrolyzed using Sparus aurata gastric proteases and varying doses of a commercial blend of acidic NSPases. Reactions occurred at 25 °C for 3 h under typical fish stomach pH conditions (3.5–5.6). We modeled the hydrolytic process using response surface methodology, focusing on the released peptides and carbohydrates. The main finding was the efficient control of the degree of protein hydrolysis. We achieved 6–25% hydrolysis for peptides below 10 kDa by adjusting the carbohydrase dose and reaction pH. This work confirms that acidic commercial NSPases improve soybean flour protein hydrolysis when combined with S. aurata gastric proteases. Full article

An engineered molecular motor composed of an ATP-dependent kinesin-1 monomer and an ATP-independent diffusing microtubule-associated protein is proposed, and its dynamics are studied theoretically. It is shown that the engineered motor can move directionally on microtubules towards the plus end, bearing great potential for applications in therapeutics or nanorobotics. The engineered motor can have an unloaded velocity similar to the wild-type kinesin-1 dimer, can take a mechanical (either forward or backward) step by hydrolyzing an ATP molecule under any load, and can generate the maximum force that is about half of that generated by the wild-type kinesin-1 dimer. Full article

Oxidative stress and inflammatory responses often occur concomitantly, and they are key causative factors in various human and animal diseases. Evidence suggests that mulberry leaf protein (MLP) may have potential antioxidant and anti-inflammatory properties, but there are significant challenges in enhancing their bioactivities. In this study, MLP was enzymatically hydrolyzed using papain, protamex, alkaline protease, trypsin, and neutral protease, followed by comprehensive evaluation of the antioxidant capacity, anti-inflammatory properties, and cytotoxicity of the hydrolysates. Our findings revealed that some enzymes significantly enhanced the peptide production and antioxidant activity of MLP (p < 0.01), and its activity was positively correlated with the degree of hydrolysis. Among the five hydrolysates, neutral protease hydrolysate (NeuH) exhibited the best antioxidant properties, with free radical scavenging rates of 71.58 ± 0.42% (ABTS), 26.38 ± 0.15% (OH), and 73.91 ± 0.37% (DPPH) at a concentration of 0.1 mg/mL. In addition, NeuH significantly suppressed IL-6 secretion (p < 0.01) and downregulated mRNA expression of IL-6, iNOS, and COX-2 inflammatory markers. This study not only establishes a correlation between enzymatic parameters and MLP biological functions but also demonstrates the potential of optimized MLP hydrolysates, particularly NeuH, as valuable natural antioxidant and anti-inflammatory ingredients for functional foods or nutraceuticals aimed at mitigating oxidative stress and inflammation-related disorders. Full article

Lactic acid bacteria are well known for hydrolyzing milk proteins, but their application to plant proteins remains limited. This study evaluated the ability of the cell-wall-anchored PrtS protease from two Streptococcus thermophilus strains to hydrolyze rapeseed albumins (RAs), aiming to generate bioactive peptides with potential food functionality. The specific activity of PrtS was first determined using a chromogenic substrate. RAs were then hydrolyzed using 10X- and 100X-concentrated cell pellets of each strain to assess the hydrolysis kinetics and the enzymatic mechanism. The results showed concentration-dependent hydrolysis, with protein conversion and the degree of hydrolysis increasing threefold at 100X for both strains. Despite the increased hydrolysis, the peptides produced had similar average sizes, averaging at five amino acids, indicating a consistent “one-by-one” cleavage mechanism. The in vitro testing of the RA hydrolysates produced with 100X PrtS from S. thermophilus LMD-9 revealed dose-dependent antioxidant activity comparable to native RAs. Importantly, unlike native RAs, these hydrolysates did not induce increased secretion of the pro-inflammatory mediator IL-8 in inflamed HT-29 cells, suggesting a reduced pro-inflammatory potential. These findings demonstrate that PrtS protease from S. thermophilus can effectively hydrolyze rapeseed proteins to produce functional hydrolysates with improved bioactivity profiles. Such hydrolysates have promising applications as functional ingredients in plant-based food products, contributing both to health benefits and potential food preservation through antioxidant activity. Full article

Large-scale blooms of Ulva prolifera severely impact coastal ecosystems and economic development. In addressing Ulva management, the development of high-value utilization approaches for this macroalga remains crucial. Compared to other marine algae, Ulva prolifera exhibits higher protein content with diverse amino acid profiles, and existing studies demonstrate that hydrolyzed Ulva prolifera proteins can yield biologically active peptides with functional potential. Conventional methods for producing bioactive peptides are often cost-intensive. Here, we employed in silico enzymatic hydrolysis to generate small peptides from Ulva prolifera protein. Through computer screening, molecular docking with the Keap1 protein, and molecular dynamics simulations, we identified a potential antioxidant peptide, DWS (Asp-Trp-Ser). Molecular docking and dynamics simulations revealed that DWS forms stable complexes with Keap1 by establishing hydrogen bonds and Pi bonds with conserved amino acid residues (Leu557, Gly558, Ile559, Val604, Val606, and Arg415). In vitro antioxidant assays demonstrated that DWS exhibits potent DPPH and ABTS radical scavenging activities as well as reducing power. Cellular experiments showed that DWS effectively alleviates LPS-induced oxidative stress and inflammation in RAW264.7 macrophages. Full article

Malignant tumors of the digestive system are widespread and pose a serious threat to humans. Immune escape is an important factor promoting the deterioration of malignant tumors in the digestive system. Natural killer cells (NK cells) are key members of the anti-tumor and immune surveillance system, mainly exerting cytotoxic effects by binding to the activating receptor natural killer cell group 2D (NKG2D) on their cell surface with the corresponding ligands (major histocompatibility complex class I chain-related protein A/B, MICA/B) on the surface of tumor cells. Malignant tumors of epithelial origin usually highly express NKG2D ligands such as MICA, which can attract NK cells to kill tumor cells and also serve as an important basis for NK cell-based immunotherapy. Tumor cells highly express hypoxia-inducible factor-1α (HIF-1α), which promotes the expression of matrix metalloproteinases (MMPs) and a disintegrin and metalloproteinases (ADAMs). These metalloproteinases hydrolyze MICA and other ligands on the surface of tumor cells to generate soluble molecules. These soluble ligands, when binding to NKG2D, cannot activate NK cells and also block the binding of NKG2D to MICA on the surface of tumor cells, enabling tumor cells to evade the killing effect of NK cells. Almost all organs in the digestive system originate from epithelial tissue, so the soluble ligands generated by the HIF-1α/MMPs or HIF-1α/ADAMs signaling pathways play a crucial role in evading NK cell killing. A comprehensive understanding of this immune escape process is helpful for a deeper understanding of the molecular mechanism of NK cell anti-tumor activity. This article reviews the molecular mechanisms of common digestive system malignancies evading NK cell killing, providing new insights into the mechanism of tumor immune escape. Full article

Synbiotics can be used to reduce intestinal inflammation and mitigate dysbiosis in dogs with chronic inflammatory enteropathy (CIE). Prior research has not assessed the colonic mucosal ultrastructure of dogs with active CIE treated with synbiotics, nor has it determined a possible association between morphologic injury and signaling pathways. Twenty client-owned dogs diagnosed with CIE were randomized to receive either a hydrolyzed diet (placebo; PL) or a hydrolyzed diet supplemented with synbiotic-IgY (SYN) for 6 weeks. Endoscopic biopsies of the colon were obtained for histopathologic, ultrastructural, and molecular analyses and were compared before and after treatment. Using transmission electron microscopy (TEM), an analysis of the ultrastructural alterations in microvilli length (MVL), mitochondria (MITO), and rough endoplasmic reticulum (ER) was compared between treatment groups. To explore potential signaling pathways that might modulate MITO and ER stress, a transcriptomic analysis was also performed. The degree of mucosal ultrastructural pathology differed among individual dogs before and after treatment. Morphologic alterations in enterocytes, MVL, MITO, and ER were detected without significant differences between PL and SYN dogs prior to treatment. Notable changes in ultrastructural alterations were identified post-treatment, with SYN-treated dogs exhibiting significant improvement in MVL, MITO, and ER injury scores compared to PL-treated dogs. Transcriptomic profiling showed many pathways and key genes to be associated with MITO and ER injury. Multiple signaling pathways and their associated genes with protective effects, including fibroblast growth factor 2 (FGF2), fibroblast growth factor 7 (FGF7), fibroblast growth factor 10 (FGF10), synaptic Ras GTPase activating protein 1 (SynGAP1), RAS guanyl releasing protein 2 (RASGRP2), RAS guanyl releasing protein 3 (RASGRP3), thrombospondin 1 (THBS1), colony stimulating factor 1 (CSF1), colony stimulating factor 3 (CSF3), interleukin 21 receptor (IL21R), collagen type VI alpha 6 chain (COL6A6), ectodysplasin A receptor (EDAR), forkhead box P3 (FoxP3), follistatin (FST), gremlin 1 (GREM1), myocyte enhancer factor 2B (MEF2B), neuregulin 1 (NRG1), collagen type I alpha 1 chain (COL1A1), hepatocyte growth factor (HGF), 5-hydroxytryptamine receptor 7 (HTR7), and platelet derived growth factor receptor beta (PDGFR-β), were upregulated with SYN treatment. Differential gene expression was associated with improved MITO and ER ultrastructural integrity and a reduction in oxidative stress. Conversely, other genes, such as protein kinase cAMP-activated catalytic subunit beta (PRKACB), phospholipase A2 group XIIB (PLA2G12B), calmodulin 1 (CALM1), calmodulin 2 (CALM2), and interleukin-18 (IL18), which have harmful effects, were downregulated following SYN treatment. In dogs treated with PL, genes including PRKACB and CALM2 were upregulated, while other genes, such as FGF2, FGF10, SynGAP1, RASGRP2, RASGRP3, and IL21R, were downregulated. Dogs with CIE have colonic ultrastructural pathology at diagnosis, which improves following synbiotic treatment. Ultrastructural improvement is associated with an upregulation of protective genes and a downregulation of harmful genes that mediate their effects through multiple signaling pathways. Full article

An experimental model of acute pulmonary damage was developed based on the intravenous injection of the phospholipase A₂ (PLA₂)-rich venom of Pseudechis papuanus (Papuan black snake) in mice. Venom caused pulmonary edema, with the accumulation of a protein-rich exudate, as observed histologically and by analysis of bronchoalveolar lavage fluid (BALF). In parallel, venom induced an increase in all of the pulmonary mechanical parameters evaluated, without causing major effects in terms of tracheal and bronchial reactivity. These effects were abrogated by incubating the venom with the PLA₂ inhibitor varespladib, indicating that this hydrolytic enzyme is responsible for these alterations. The venom was cytotoxic to endothelial cells in culture, hydrolyzed phospholipids of a pulmonary surfactant, and reduced the activity of angiotensin-converting enzyme in the lungs. The pretreatment of mice with the nitric oxide synthase inhibitor L-NAME reduced the protein concentration in the BALF, whereas no effect was observed when mice were pretreated with inhibitors of cyclooxygenase (COX), tumor necrosis factor-α (TNF-α), bradykinin, or neutrophils. Based on these findings, it is proposed that the rapid pathological effect of this venom in the lungs is mediated by (a) the direct cytotoxicity of venom PLA₂ on cells of the capillary–alveolar barrier, (b) the degradation of surfactant factor by PLA₂, (c) the deleterious action of nitric oxide in pulmonary tissue, and (d) the cytotoxic action of free hemoglobin that accumulates in the lungs as a consequence of venom-induced intravascular hemolysis. Our findings offer clues on the mechanisms of pathophysiological alterations induced by PLA₂s in a variety of pulmonary diseases, including acute respiratory distress syndrome (ARDS). Full article

The need to find sustainable solutions to conventional plastics has driven research into alternative materials, including bioplastics, which represent a promising option for reducing pollution and enhancing the value of renewable resources. In this study, bioplastics made from polyvinyl alcohol (PVA) and proteins extracted from the larvae of Black Soldier Fly (BSF), an insect capable of converting organic waste into high-value biomass, were produced and characterized. The proteins were obtained by hydrolysis of defatted BSF larvae with superheated water, avoiding harsh chemical reagents. Next, polymer films were fabricated by mixing PVA and hydrolyzed BSF proteins in different proportions and analyzed for morphological, physical-chemical, mechanical and biodegradability characteristics. The results obtained show that as the BSF protein content increases, the films show a reduction in thermal stability and mechanical properties, and also, they exhibit higher biodegradability, correlated with higher wettability, solubility and ability to absorb moisture. This research highlights the value of using organic waste-fed insects as a resource for bioplastic production, offering an alternative to traditional polymers and contributing to the transition to sustainable materials. Full article

Soy protein isolate (SPI) is a high-purity protein from defatted soybeans, providing emulsifying and gelling functions for plant-based foods and supplements. Hydrolysis can facilitate the production of bioactive small-molecule proteins or peptides with potential functional applications. In this study, 20% hydrolyzed soy protein (20% HSP) was prepared from SPI, and the effects of 20% HSP and SPI on alleviating oxidative stress in Caenorhabditis elegans (C. elegans) and regulating immune–gut microbiota in cyclophosphamide (CTX)-induced immunocompromised BALB/c mice were investigated. In C. elegans, both SPI and 20% HSP (300 μg/mL) enhanced locomotive activities, including body bending and head thrashing, and improved oxidative stress resistance under high glucose conditions. This improvement was mediated by increased antioxidant enzyme activities (SOD, CAT, and GSH-Px), while malondialdehyde (MDA) content was reduced by 60.15% and 82.28%, respectively. Both of them can also significantly extend the lifespan of normal C. elegans and paraquat-induced oxidative stress models by inhibiting lipofuscin accumulation. This effect was mediated through upregulation of daf-16 and suppression of daf-2 and akt-1 expression. In immunocompromised mice, 20% HSP alleviated CTX-induced immune dysfunction by increasing peripheral white blood cells and lymphocytes, attenuating thymic atrophy, and reducing hepatic oxidative stress via MDA inhibition. Gut microbiota analysis revealed that 20% HSP restored microbial balance by suppressing Escherichia-Shigella and enriching beneficial genera, like Psychrobacter. These findings highlight 20% HSP and SPI’s conserved anti-aging mechanisms via daf-16 activation in C. elegans and immune–gut modulation in mice, positioning them as plant-derived nutraceuticals targeting oxidative stress and immune dysregulation. Full article

Dipeptidyl peptidase-4 (DPP-4) inhibitors play a critical role in the management of type 2 diabetes; however, some synthetic drugs may cause adverse effects. Natural peptides derived from rice offer a promising alternative due to their favorable biocompatibility and development potential. In this study, an AI-assisted virtual screening pipeline integrating machine learning, molecular docking, and molecular dynamics (MD) simulations was established to identify and evaluate rice-derived DPP-4 inhibitory peptides. A random forest classification model achieved 85.37% accuracy in predicting inhibitory activity. Peptides generated by simulated enzymatic hydrolysis were screened based on machine learning and docking scores, and four proline-rich peptides (PPPPPPPPA, PPPSPPPV, PPPPPY, and CPPPPAAY) were selected for MD analysis. The simulation results showed that PPPSPPPV formed a stable complex with the DPP-4 catalytic triad (Ser592–Asp670–His702) through electrostatic and hydrophobic interactions, with low structural fluctuation (RMSF < 1.75 Å). In vitro assays revealed that PPPPPY exhibited the strongest DPP-4 inhibitory activity (IC₅₀ = 153.2 ± 5.7 μM), followed by PPPPPPPPA (177.0 ± 6.0 μM) and PPPSPPPV (216.3 ± 4.5 μM). This study presents an efficient approach combining virtual screening and experimental validation, offering a structural and mechanistic foundation for the development of natural DPP-4 inhibitory peptides as candidates for functional foods or adjunct diabetes therapies. Full article