Search Results (1,934)

Mollusk-derived peptides are an expanding class of marine bioactive molecules that link food-protein utilization with pharmaceutical peptide discovery. They are derived from taxonomically and biologically diverse sources such as edible gastropods, bivalves, cephalopods and highly modified conopeptides from cone snails. However, there is a lack of integrated understanding of sources, structures and functions of these peptides and their potential applications in food science, pharmacology, and venom research. In this review, the current knowledge related to mollusk-derived peptides from a food–pharma perspective is summarized, including taxonomic sources, tissue substrates, enzymatic hydrolysis, purification, sequence identification, reported bioactivities and structure–function relationships. The peptides derived from food are primarily short linear peptides from muscle, mantle, viscera, collagen, gelatin and processing by-products. These peptides have mainly been investigated for antioxidant, Angiotensin-I-converting enzyme inhibitory, anti-inflammatory, mineral-binding, gut-health, and metabolic activities. However, the biological functions of endogenous peptides and peptides from cone snails are often associated with cysteine-rich scaffolds and disulfide connectivity and post-translational modifications that confer antimicrobial activity, neuromodulation, and receptor selectivity. For these systems, the activity depends not on any single parameter but on the peptide length, amino acid sequence, charge distribution, hydrophobicity, amphipathicity, secondary structure and chemical modifications. Further progress requires improved sequence-level validation, mechanism-driven bioassays, in vivo and clinical evidence, safety assessment, and feasible purification and delivery strategies for mollusk peptides into functional foods, nutraceuticals and peptide-based therapeutics. Full article

Hydrolyzed collagen preparations have attracted increasing attention because their biological properties may vary according to collagen source, peptide composition, and physicochemical characteristics. In this study, Richi I II III Collagen (HTCP), a hydrolyzed type I, II, and III collagen preparation derived from chicken sternum (keel) and manufactured by CNABIOTECH Co., Ltd. (Cheongju-si, Republic of Korea), was physicochemically characterized and evaluated for antioxidant and skin-related biological activities. Physicochemical characterization included analyses of amino acid composition and molecular weight distribution, while biological activities were assessed using ABTS and DPPH radical scavenging assays and human skin cell-based models. HTCP showed distinct responses in the two radical scavenging assays, with ABTS radical scavenging activity reaching 80.4 ± 0.0% at 100 mg/mL, whereas DPPH radical scavenging activity remained comparatively low (13.1 ± 4.6%). No cytotoxicity was detected in human dermal fibroblasts (HDF) or human epidermal keratinocytes (HEKn) at the concentrations tested. HTCP exhibited 101.65 ± 1.28% collagenase inhibition at 10% and significantly increased type I collagen, type III collagen, elastin, hyaluronic acid (HA), HAS2, and HAS3 levels, while reducing MMP-1 and HYAL1 levels. Collectively, these findings demonstrate changes in selected ECM- and HA-related protein levels in human skin cells following HTCP treatment under in vitro conditions, supporting further investigation of HTCP as a collagen-derived ingredient for skin-related applications. Full article

Oilseed meal, the primary by-product of oil extraction, is rich in protein, dietary fiber, and minerals, offering significant development potential. However, its application in high-value feed and food is severely restricted due to anti-nutritional factors, leading to resource waste and environmental issues. Solid-state fermentation (SSF) provides a green and efficient approach for the high-value utilization of oilseed meal. This review comprehensively discusses the entire process of strain selection, fermentation strategies, and application of active products in the SSF of oilseed meal. Regarding strain selection, Bacillus spp. degrade macromolecular proteins and inhibit microbial contamination through protease and antimicrobial peptide production. Lactobacillus spp. enhance flavor and safety by producing acids and flavor compounds. Aspergillus spp. decompose cell walls and degrade phytate using their cellulase and phytase systems. For fermentation strategies, mixed fermentation achieves functional complementarity, enzyme–fungus synergy enhances substrate conversion, segmented fermentation optimizes the microbial environment, and physical field assistance boosts enzyme activity, collectively improving fermentation efficiency and nutritional quality. In product applications, fermented oilseed meal serves as both high-quality protein feed and a source of functional peptides and active polysaccharides with antioxidant and immunomodulatory activities, showing potential for functional foods and biomedicine. In conclusion, SSF technology effectively degrades anti-nutritional factors, improving the nutritional value and adding value to oilseed meal, thus representing a key strategy for resource conversion. Future efforts should prioritize high-performance strain selection, intelligent process monitoring, and green preparation of active products to promote industrial application and sustainable development. Full article

Selenium-dependent antioxidant systems are critical for neuronal redox balance, but whether Parkinson’s disease (PD) involves systemic selenium deficiency or selective utilization impairment remains unclear. Using Parkinson’s Progression Markers Initiative (PPMI) proteomic data, we identified specific downregulation of glutathione peroxidase 3 (GPX3) in cerebrospinal fluid in PD, suggesting a compartment-specific alteration in GPX3-related antioxidant defense rather than a uniform systemic selenium deficit. Inorganic selenium sources suffer from low bioavailability and narrow therapeutic windows. We therefore developed a selenium-enriched peptide fraction (IPP-Se-F12) via controlled selenization of Idesia polycarpa Maxim. cake meal peptides, and characterized its selenium content, size distribution, and radical-scavenging activity. In SH-SY5Y and nematode models, IPP-Se-F12 attenuated 6-hydroxydopamine (6-OHDA)-induced cell death and rescued locomotor and dopamine-dependent behaviors more effectively than sodium selenite treatment. RNAseq further showed that IPP-Se-F12 treatment was associated with transcriptional changes in dephosphorylation, axon-guidance, and GPX3-centered antioxidant networks, including increased expression of gpx-3 and gpx-5. This study supports IPP-Se-F12 as a plant-derived selenium-associated peptide fraction with protective activity in cellular and nematode models and identifies GPX-related antioxidant regulation as a candidate mechanism for further investigation. Full article

Preservation of mitochondrial integrity has emerged as a central hub in the anti-inflammatory effect of exercise. This narrative review advances a framework in which mitochondrial damage-associated molecular patterns (mtDAMPs) serve as the mechanistic bridge between exercise and inflammation. Mitochondrial dysfunction releases mtDAMPs, including mitochondrial DNA (mtDNA), reactive oxygen species, cardiolipin, N-formyl peptides, and ATP, which activate cGAS–STING, the NLRP3 inflammasome, TLR9, AIM2, ZBP1, and NF-κB signaling. Crosstalk among these pathways allows mild mitochondrial damage to escalate into chronic inflammation. Exercise opposes this cascade through the AMPK–PGC-1α axis, which coordinately activates four mitochondrial quality control (MQC) modules: biogenesis, antioxidant defense, dynamics, and mitophagy. The cardiovascular system illustrates this framework, as myocardial inflammation runs mainly through mtDNA–cGAS–STING signaling and vascular inflammation through oxidized mtDNA–NLRP3 signaling, while cardiovascular aging engages both axes at once. Throughout, exercise refers to repeated training rather than to a single bout, and the framework targets middle-aged and older adults with, or at risk of, cardiovascular disease. The upstream half of the sequence, in which training raises mitochondrial content and antioxidant capacity, rests on human muscle biopsy data; the downstream half remains largely preclinical. MQC is therefore proposed as a testable target rather than an established one. Full article

Plant-derived bioactive peptides are widely investigated for their effects on intestinal epithelial function using Caco-2 cells, with reported antioxidant, anti-inflammatory, antihypertensive and antidiabetic activities. However, this literature remains heterogeneous and has rarely addressed whether the tested material corresponds to the actual bioactive species. This PRISMA-compliant systematic review searched PubMed and Scopus for studies on plant-derived peptides, hydrolysates or digests in Caco-2 cells, identifying 34 eligible studies. The material tested in each study was classified a priori as a purified or synthetic single peptide, an ultrafiltration or chromatographic fraction, a whole hydrolysate or gastrointestinal digest, or an intact parent protein used as a comparator, because these forms do not support equivalent structure–activity inference. Risk of bias was assessed using the QUIN tool, adopted in the absence of an instrument validated for nutritional cell-culture research. For each study, metabolic characterisation of the tested peptide and the physiological relevance of the concentrations used were evaluated. Directionally consistent bioactivity, including antioxidant, anti-inflammatory, antihypertensive and antidiabetic effects, was observed across most functional domains, although effect magnitude and stress dependence varied considerably. Mass-based concentrations did not uniformly exceed a conservative exploratory luminal benchmark (0.1–1 mg/mL), but upper-range experiments exceeded it by approximately 25-fold in the antioxidant domain, 50-fold in the anti-inflammatory and antidiabetic domains, and 500-fold in the viability domain; in vivo confirmation was available for a single identified metabolite (LTFPG). Because the primary studies did not report effect estimates with measures of precision, the synthesis is qualitative, based on vote counting by direction of effect, and no pooled effect sizes, heterogeneity statistics or certainty ratings were derived. Overall, plant-derived peptides show directionally consistent bioactivity in Caco-2 models, but the evidence rarely identifies the responsible molecular species or confirms physiological attainability. Future work should prioritise metabolic characterisation, exposure-justified concentrations, and multi-omics approaches to clarify underlying mechanisms. Full article

Animal-processing by-products contain collagen, myofibrillar proteins, blood proteins, whey proteins, and egg proteins that can be converted into peptide-rich food ingredients. Within a single application-oriented framework, this review integrates source heterogeneity, process control, peptide-profile characterization, tiered functional evidence, food-matrix performance, and regulatory substantiation. Evidence is evaluated for antioxidant, ACE-inhibitory, antimicrobial, DPP-IV-inhibitory, anti-inflammatory, mineral-binding, and taste-modulating functions, while distinguishing chemical assays, cell models, animal studies, human interventions, and tests in real-food matrices. Potential applications include functional foods, dietary supplements, natural preservation, flavor systems, texture modification, active packaging, and oral delivery. Translation remains limited by raw-material heterogeneity, batch variability, sensory defects, processing and gastrointestinal instability, uncertain bioavailability, incomplete safety assessment, and poorly defined regulatory claims. Future work should prioritize source traceability, peptide fingerprints, food-matrix validation, human exposure data, and scalable food-grade production. Compositionally defined peptide mixtures with reproducible functionality may be more practical than single highly purified sequences. Full article

This study used locally sourced black, red, and white quinoa from Zhangjiakou as experimental materials to optimize the preparation process of quinoa antioxidant peptides and identify their sequence characteristics. Protein was extracted using the alkali-soluble acid precipitation method. The optimal hydrolytic enzyme was selected by comparing the hydrolysis effects of eight proteases. Enzymatic hydrolysis conditions were optimized using single-factor experiments and response surface methodology. After purification by Sephadex G-15 gel filtration chromatography, peptide sequences were identified by liquid chromatography–tandem mass spectrometry (LC-MS/MS) combined with De novo sequencing technology. The results showed that black quinoa and alcalase were identified as the optimal raw material and hydrolytic enzyme, respectively. The optimal enzymatic hydrolysis conditions were an enzyme dosage of 4000 U·g⁻¹, hydrolysis time of 3.5 h, temperature of 42 °C, and pH 7.6, under which the average DPPH radical scavenging rate reached 86.61%. The purified G-1 fraction exhibited the highest antioxidant activity. A total of 1549 peptide sequences with confidence ≥90% were identified, among which peptides containing two or more hydrophobic amino acids accounted for 60.62%. This compositional feature is consistent with structural characteristics commonly associated with antioxidant peptides. This study provides a reference for the processing of quinoa-based functional ingredients. Full article

A wound is defined as disruption or destruction of tissue integrity. In order to support healing in wound management, a good wound bed free of necrotic tissue and infection is desired, but intensive chemical antiseptics will cause cell destruction and delay healing. In order for wound healing to be rapid, the nature and contamination of the wound should be taken into consideration and appropriate methods should be utilized. Today, many types of algae are frequently preferred as an alternative to medicine and are the subject of research. Since the metabolites contained in algae display several notable biological activities such as antimicrobial, anti-inflammatory, and antioxidant, they are a good option in wound treatment. Algae contain pigments, peptides, fatty acids, and polysaccharides that are crucial for wound healing. These compounds play vital roles at all stages of the healing process by accelerating cell proliferation, promoting collagen deposition, scavenging reactive oxygen species (ROS), and regulating key inflammatory cytokines. Furthermore, their unique physical and functional properties enable the development of novel bio-inspired wound dressings, hydrogels, and drug-delivery scaffolds. This review discusses the bioactive metabolites found in algae that are effective in wound healing. Full article

Diabetes mellitus is a pervasive global health crisis, with type 2 diabetes (T2D) representing the majority of cases. While conventional pharmacological therapies exist, suboptimal efficacy, adverse effects, and inadequate glycemic control in a substantial proportion of patients highlight the need for complementary strategies. There is growing scientific and clinical interest in plant-based functional foods, including Ribes nigrum L. (blackcurrant), which is rich in bioactive phytochemicals such as anthocyanins, flavonols, and phenolic acids. This review evaluates the antidiabetic and metabolic regulatory potential of blackcurrant, focusing on its multi-target mechanisms of action. Available experimental evidence suggests that blackcurrants may influence glucose metabolism through several mechanisms, including inhibition of carbohydrate-digesting enzymes (α-amylase and α-glucosidase), modulation of intestinal glucose transporters (SGLT1 and GLUT2), and potential modulation of insulin sensitivity involving AMPK signaling and GLUT4 translocation. In addition, blackcurrant constituents may stimulate glucagon-like peptide-1 (GLP-1) secretion, modulate gut microbiota composition, and exert antioxidant and anti-inflammatory effects that counteract key drivers of insulin resistance and β-cell dysfunction. Supporting human studies indicate that blackcurrant consumption has been associated with attenuation of postprandial glycemic and insulinemic responses and modest improvements in cardiometabolic biomarkers, although findings remain limited by study size, duration, and formulation heterogeneity. Overall, Ribes nigrum represents a promising dietary adjunct for the prevention and management of T2D through multi-target metabolic regulation. Full article

To realize the high-value valorization of cold-pressed walnut meal, walnut oligopeptides were fabricated via synchronous dual-enzyme hydrolysis combined with activated carbon decolorization and membrane separation purification. We optimized the overall preparation process and systematically characterized the products, including their amino acid profile, in vitro antioxidant capacity, cytoprotective effects against H₂O₂-triggered oxidative injury in PC12 cells, and regulatory activity toward acetylcholinesterase (AChE). The optimal hydrolysis conditions were identified as pH 10.0, total enzyme dosage of 11,000 U/g, a trypsin-to-alkaline protease ratio of 2.1:1, solid–liquid ratio of 1:26, temperature of 51 °C and reaction duration of 4 h, which produced a hydrolysis degree of 33.02%. The optimized decolorization parameters were pH 5.2, activated carbon dosage of 2.3%, treatment at 58 °C for 43 min, with a peptide recovery rate reaching 83.35%. Cold-pressed walnut meal is rich in glutamic acid, arginine and aspartic acid, which lay the molecular foundation for the bioactive properties of the derived oligopeptides. In vitro tests demonstrated that the oligopeptides possessed strong scavenging ability against hydroxyl, DPPH and superoxide anion radicals (clearance rates of 90.18%, 81.72% and 85.80%, respectively), and maintained 73.21% of antioxidant activity after simulated gastrointestinal digestion. Moreover, walnut oligopeptides at 0.8 mg/mL showed no cytotoxicity and afforded a 79.88% protective effect against oxidative damage. The peptides significantly boosted SOD and GSH-Px activities, lowered MDA accumulation, and strongly suppressed AChE activity, performing better than donepezil hydrochloride. This efficient, eco-friendly technique achieves high-value utilization of walnut processing by-products. The obtained oligopeptides possess great potential as natural antioxidants and neuroprotective ingredients for functional food development. Full article

Amphibians of the family Phyllomedusidae produce complex cutaneous secretions with ecological and pharmacological relevance. Here, we investigated the skin morphology of Pithecopus oreades and P. azureus and the antioxidant function of the tryptophyllin PaT-2 in microglial cells. Histological and histochemical analyses revealed a conserved glandular organization, with mucous glands rich in neutral mucopolysaccharides and serous glands containing acidic and sulfated polysaccharides, concentrated predominantly in the dorsal and cephalic regions. MALDI mass spectrometry imaging showed that PaT-2 (m/z 696.4) is heterogeneously distributed. A second ion (m/z 1626.8), assigned to a truncated form of a phylloseptin-like antimicrobial peptide, was predominantly localized in limb tissues and partially overlapped with PaT-2, suggesting co-deployment of antioxidant and antimicrobial molecules on the skin. In BV2 microglial cells, menadione (10 µM) induced oxidative stress reflected by increased oxidized glutathione (GSSG) and higher total glutathione levels, consistent with a compensatory increase in glutathione synthesis. Synthetic PaT-2 (50 µM) was associated with numerically lower GSSG accumulation and a smaller increase in total glutathione when co-administered with menadione, showing no cytotoxicity while demonstrating modulation of endogenous glutathione status. These findings advance the integumentary biology of Pithecopus, suggest differences in peptide distribution between the specimens examined, and extend the antioxidant characterization of PaT-2 to the level of glutathione status, supporting its further investigation as a candidate molecule for oxidative stress-related research. Full article

Plant protein-derived bioactive peptides have attracted increasing interest as potential ingredients for health-promoting functional foods because of their reported cardiometabolic, antioxidant, anti-inflammatory, immunomodulatory, antimicrobial, gastrointestinal, and satiety-related activities. However, the field remains dominated by peptide discovery, in silico prediction, enzyme-inhibition assays, simulated digestion, and preclinical models, whereas successful translation into clinically supported and technologically viable food products is still limited. This review critically examines the gap between mechanistic promise and functional food implementation. It integrates evidence on plant protein sources, peptide-generation strategies, structure–activity relationships, gastrointestinal stability, intestinal transport, local gut activity, food-matrix interactions, processing effects, encapsulation, sensory constraints, human efficacy, regulatory substantiation, commercial feasibility, and consumer acceptance. Particular attention is given to the limited predictive value of isolated in vitro activity when peptides are exposed to digestion, epithelial barriers, complex food matrices, realistic processing conditions, and achievable dietary doses. The review also highlights that systemic absorption is not the only relevant pathway, as selected peptides may act locally within the gastrointestinal tract. Overall, the evidence indicates that peptide discovery should not be treated as the principal endpoint of research. Future progress will require translation-oriented development in which bioactivity, digestion stability, matrix compatibility, sensory quality, manufacturing reproducibility, realistic intake, human evidence, and regulatory credibility are evaluated as interdependent criteria. The most promising plant-derived peptides will therefore be those that retain sufficient activity and acceptability under real conditions of food production and consumption. Full article

Yellowfin tuna (Thunnus albacares) processing by-products are underutilized resources rich in high-quality proteins that can be valorized into bioactive ingredients. In this study, proteins from yellowfin tuna tail bones were hydrolyzed using either an endogenous protease extract recovered from tuna viscera or commercial trypsin. The endogenous extract was characterized and exhibited optimal proteolytic activity at pH 8 and 40 °C. Comparative bioactivity assessment showed that trypsin-derived hydrolysates exhibited significantly higher antioxidant capacity, with ABTS and DPPH values of 11.8 ± 0.04 and 13.3 ± 0.40 mg Trolox/g, respectively, compared with 10.1 ± 0.12 and 7.3 ± 0.21 mg Trolox/g for hydrolysates produced with endogenous enzymes. Trypsin hydrolysates also showed stronger dipeptidyl peptidase-IV (DPP-IV) inhibition (IC₅₀ = 0.83 ± 0.37 mg/mL) than endogenous-enzyme hydrolysates (IC₅₀ = 1.60 ± 0.47 mg/mL). Remarkably, hydrolysates generated with the endogenous enzymatic consortium exhibited exceptionally potent angiotensin-converting enzyme (ACE) inhibitory activity (IC₅₀ = 0.008 ± 0.004 mg/mL), outperforming trypsin hydrolysates (IC₅₀ = 0.01 ± 0.007 mg/mL). Neither hydrolysate showed evidence of acute toxicity in the Artemia salina model at the tested concentrations, supporting their favorable performance in this preliminary toxicity screening assay. Considering that nearly two-thirds of total fish biomass is discarded during processing, this integrated bioprocess demonstrates a sustainable strategy for the simultaneous valorization of skeletal and visceral waste streams. By employing endogenous enzymes as biocatalysts, this approach reduces dependence on commercial proteases, mitigates environmental burdens, and supports the development of a circular marine bioeconomy through the production of highly potent, peptide-rich functional ingredients with promising cardiovascular health applications. Further toxicological evaluation is required to confirm their safety for food and nutraceutical applications. Full article

Glucose and lipid metabolism disorders are closely associated with type 2 diabetes mellitus (T2DM), obesity, hyperlipidemia, and metabolic dysfunction-associated steatotic liver disease (MASLD). Gynura divaricata (L.) DC., traditionally consumed as both a food and folk medicine, has attracted increasing attention for its potential regulatory effects on glucose and lipid metabolism. Existing in vitro and in vivo studies suggest that G. divaricata extracts and candidate bioactive constituents, including flavonoids, polysaccharides, phenolic acids, and peptides, may improve metabolic phenotypes such as hyperglycemia, dyslipidemia, and insulin resistance. These effects may involve the regulation of intestinal carbohydrate hydrolysis, insulin signaling, gut microbial homeostasis, pancreatic β-cell function, lipid metabolism, oxidative stress, and chronic inflammation. However, human evidence remains limited, and most studies have investigated compound formulations or combined interventions, which are insufficient to establish the clinical efficacy of G. divaricata as a standalone preparation. This review summarizes the major bioactive constituents of G. divaricata, reviews the current evidence for its glucose-lowering and lipid-regulating effects and related antioxidant and anti-inflammatory mechanisms, and discusses the limitations of existing research. This study aimed to provide a reference for elucidating the mechanisms by which G. divaricata regulates glucose and lipid metabolism and for its future clinical translation. Full article