Search Results (240)

This study presents a strategy to develop crayfish shell peptides with enhanced antioxidant and angiotensin-I-converting enzyme (ACE) inhibitory properties. Crayfish shell protein hydrolysates (CSPH1–3) with different molecular weights were analyzed. CSPH2 (3–5 kDa) exhibited the strongest antioxidant activities, which could scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) and the 2,2′-azobis(3-ethylbenzothiazoline-6-sulfonic acid) sodium salt (ABTS) radical by (77.40 ± 4.54)% and (91.59 ± 0.30)%, respectively, and ACE inhibition activity of (64.74 ± 0.64)%. CSPH2 was further separated into three fractions, and CSPHF2 showed the maximum biological activity. The sequences of the purified antioxidant peptide (APAPLPPPAP) and ACE inhibitory peptide (QGPDDPLIPIM) were identified by liquid chromatography–tandem mass spectrometry (LC-MS/MS) in CSPHF2. These peptides increased the nitric oxide (NO) concentration and decreased the endothelin-1 (ET-1) content in human umbilical vein endothelial cells (HUVECs) in a dose-dependent manner, while also inhibiting reactive oxygen species (ROS). In addition, CSPH showed protective effects in terms of oxidative damage to HepG2 cells induced by H₂O₂. These findings suggest that crayfish shell peptides have potential applications as ingredients in antihypertensive agents and antioxidants, offering significant health benefits when consumed. Full article

Hypertension is a major pathogenic contributor to cardiovascular diseases, primarily mediated through activation of the angiotensin-converting enzyme (ACE) system. Food-derived ACE-inhibitory peptides represent a promising alternative to synthetic drugs due to their favorable safety profile and minimal side effects. ACE-inhibitory peptides have been extensively identified from various foods, with their antihypertensive activity and molecular mechanisms comprehensively characterized through in vitro and in vivo studies. ACE-inhibitory peptides can be prepared by methods such as natural extraction, enzymatic hydrolysis, and fermentation. The production process significantly modulates structural characteristics of the polypeptides including peptide chain length, amino acid composition, and sequence, consequently determining their functional activity. To comprehensively elucidate the gastrointestinal stability and mechanisms action of ACE-inhibitory peptides, integrated experimental approaches combining both in vitro and in vivo methodologies are essential. This review systematically examines current advances in food-derived ACE-inhibitory peptides in terms of sources, production, structure, in vivo and in vitro activities, and bioavailability. Full article

In order to innovatively develop high-activity ACE inhibitory peptides from edible fungi, the conditions for a double-enzymatic hydrolysis preparation of ACE inhibitory peptides from Flammulina velutipes were optimized by response surface methodology. After purification by macroporous resin, gel chromatography, and RP-HPLC, a crude peptide fraction was obtained; its ACE inhibition rate was 85.73 ± 0.95% (IC₅₀ = 0.83 ± 0.09 mg/mL). Based on LC-MS/MS sequencing, the four novel peptides, namely, FAGGP, FDGY, FHPGY, and WADP, were screened by computer analysis and molecular docking technology. The four peptides exhibited a binding energy between −9.4 and −10.3 kcal/mol, and formed hydrogen bonds with Tyr523, Ala354, and Glu384 in the S1 pocket, Tyr520 and His353 in the S2 pocket, and His383 in the HEXXH zinc-coordinating motif of ACE, indicating their good affinity with the ACE active site. The IC₅₀ values of the four ACE inhibitory peptides were 29.17, 91.55, 14.79, and 41.27 μM, respectively, suggesting that these peptides could potentially contribute to the development of new antihypertensive products. Full article

Chicken feathers constitute a major by-product from the poultry industry, with a potential environmental impact and significant difficulties in their management. This study aimed to develop a sustainable method to hydrolyse chicken feathers and evaluate the effects of microwave (MW) irradiation pre-treatment in the generation of bioactive hydrolysates by simple or sequential hydrolysis with Alcalase. The hydrolysate with MW irradiation pre-treatment and Alcalase (2%, 2 h) (MWA) showed the highest overall antioxidant activity and neprilysin-inhibitory activity (55%), whereas samples without MW irradiation pre-treatment exerted the highest inhibitory activity of dipeptidyl peptidase IV (DPP IV) and angiotensin-converting enzyme (ACE-I), with values close to 50 and 70%, respectively. Mass spectrometry in tandem of bioactive hydrolysates was performed, and an in silico approach was used to characterise the obtained sequences. These results confirmed that MW irradiation pre-treatment improved Alcalase hydrolysis, leading to the generation of bioactive peptides with potential multifunctional properties, including antioxidant, antidiabetic, and antihypertensive activities. Moreover, this study highlights the potential of combining MW irradiation and enzymatic hydrolysis as a sustainable strategy for the revalorisation of chicken feathers. Full article

This study explores the identification, characterization, and biological evaluation of angiotensin I-converting enzyme (ACE)-inhibitory peptides derived from enzymatic hydrolysates of crucian carp swim bladders. Following sequential purification by size-exclusion and reversed-phase chromatography, two bioactive peptides—Hyp-Gly-Ala-Arg (Hyp-GAR) and Gly-Ala-Hyp-Gly-Ala-Arg (GA-Hyp-GAR)—were identified using ultra-high-performance liquid chromatography coupled with linear ion trap–Orbitrap tandem mass spectrometry. The synthetic peptides demonstrated potent ACE-inhibitory activity in vitro, with IC₅₀ values of 12.2 μM (Hyp-GAR) and 4.00 μM (GA-Hyp-GAR). Molecular docking and enzyme kinetics confirmed competitive inhibition through key interactions with ACE active site residues and zinc coordination. In vivo antihypertensive activity was evaluated in spontaneously hypertensive rats, revealing that GA-Hyp-GAR significantly reduced systolic blood pressure in a dose-dependent manner. At a dose of 36 mg/kg, GA-Hyp-GAR reduced systolic blood pressure by 60 mmHg—an effect comparable in magnitude and timing to that of captopril. Mechanistically, GA-Hyp-GAR modulated levels of angiotensin II, bradykinin, endothelial nitric oxide synthase, and nitric oxide. A 90-day subchronic oral toxicity study in mice indicated no significant hematological, biochemical, or histopathological alterations, supporting the peptide’s safety profile. These findings suggest that GA-Hyp-GAR is a promising natural ACE inhibitor with potential application in functional foods or as a nutraceutical for hypertension management. Full article

The venom of Nemopilema nomurai jellyfish represents a promising source of bioactive compounds with potential pharmacological applications. In our previous work, we identified two novel angiotensin-converting enzyme (ACE)-inhibitory peptides—IVGRPLANG (896.48 Da) and IGDEPRHQYL (1227.65 Da)—isolated from N. nomurai venom hydrolysates via papain digestion. In this study, we conducted a detailed biochemical and computational characterization of these peptides. The IC₅₀ values were determined to be 23.81 µM for IVGRPLANG and 5.68 µM for IGDEPRHQYL. Kinetic analysis using Lineweaver–Burk plots revealed that both peptides act as competitive ACE inhibitors, with calculated inhibition constants (K_i) of 51.38 µM and 5.45 µM, respectively. To assess the structural stability of the ACE–peptide complexes, molecular dynamics simulations were performed. Root mean square deviation (RMSD) and root mean square fluctuation (RMSF) analyses provided insights into complex stability, while interaction fraction analysis elucidated key bond types and residue–ligand contacts involved in binding. Furthermore, a network pharmacology approach was employed to predict therapeutic targets within the renin–angiotensin–aldosterone system (RAAS). Eleven target proteins were identified: IVGRPLANG was associated with REN, ACE, CTSB, CTSS, and AGTR2; IGDEPRHQYL was linked to REN, AGT, AGTR1, AGTR2, KNG1, and BDKR2. Molecular docking analyses using HADDOCK software (version 2.4) were conducted for all targets to evaluate binding affinities, providing further insight into the peptides’ therapeutic potential. Full article

Biotechnology has increasingly focused on cyanobacteria as these microorganisms are a rich source of secondary metabolites with significant potential for various industries. Cyanobacterial metabolites have been described to have a wide range of biological activities, including cytotoxicity in cancer cells, inhibition of pathogenic bacteria and fungi, and inhibition of various enzymes, demonstrating a great diversity of bioactive compounds. The cyanobacterium Microcystis aeruginosa is well known for its toxicity and production of the cyanotoxin microcystin. However, another peptide produced by this cyanobacterium, microginins, has significant biotechnological potential. These linear pentapeptides were initially discovered for their angiotensin-converting enzyme (ACE) inhibitory activity. Subsequent studies have explored the full potential of this peptide, revealing its ability to inhibit other enzymes as well. This review aims to compile and systematize the microginins with biotechnological potential described in the literature, as well as outline their main structural characteristics and the predominant methodologies for their isolation and identification. Full article

The search for sustainable and health-promoting food sources has increased interest in edible insects, which are rich in proteins and bioactive compounds with potential nutraceutical applications. In this study, we evaluated the bioactive properties of protein hydrolysates derived from Aegiale hesperiaris (maguey white worm, WW) and Comadia redtenbacheri (maguey red worm, RW), two culturally and economically significant insect species in Mexico. Hydrolysates were obtained via enzymatic treatments: either single hydrolysis with pepsin (PH) or sequential hydrolysis with pepsin followed by trypsin (PTH). The PTH hydrolysates exhibited strong antioxidant activity, with 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical inhibition above 90% and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity between 75–85%. Additionally, they showed significant angiotensin-converting enzyme (ACE) inhibitory activity, reaching IC₅₀ values of 0.35 and 0.017 $\mathsf{\mu }$g/mL for WWPH and RWPH, respectively—the latter outperforming the commercial drug Enalapril (IC₅₀ = 0.11 $\mathsf{\mu }$g/mL). SDS-PAGE analysis revealed low molecular weight peptides (<10 kDa), especially between 5–9 kDa, associated with enhanced bioactivity. Peptides from RW also showed low Hill coefficients, suggesting a gradual and sustained interaction with ACE. These findings support the use of insect-derived hydrolysates as promising multifunctional ingredients for the development of functional foods targeting cardiovascular health. Full article

Antarctic krill (Euphausia superba) is a nutrient-rich marine resource. Although several terrestrial proteases have been used to prepare Antarctic krill peptides (AKPs), there has been no report on the preparation of AKPs using a marine protease. Here, marine bacterial protease A69 was used to prepare AKPs with multi-bioactivities. Through optimizing hydrolysis parameters, we established a process for AKPs preparation by hydrolyzing Antarctic krill powder with A69. In the prepared AKPs, peptides less than 3000 Da and 1000 Da accounted for 99.23% and 88.37%, respectively. The scavenging ratios of the AKPs to ABTS⁺, DPPH· and ·OH reached 93.23 ± 0.09%, 99.90 ± 0.15%, and 93.90 ± 0.47%, respectively. The AKPs also had high angiotensin-converting enzyme (ACE)-inhibitory activity, with an IC₅₀ of 0.22 ± 0.04 mg/mL. At 40 mg/mL, the AKPs inhibited α-glucosidase and dipeptidyl peptidase IV (DPP-IV) activities by 7.18% and 13.62%, respectively, and displayed antibacterial activity to Escherichia coli. Moreover, 14 antioxidant peptides, 24 ACE-inhibitory peptides, 2 α-glucosidase-inhibitory peptides, and 10 DPP-Ⅳ-inhibitory peptides were identified from the AKPs. These results demonstrate that the prepared AKPs contain diverse bioactive peptides and have multi-bioactivities. This study indicates that marine bacterial protease A69 has promising application potential in preparing AKPs with multi-bioactivities. Full article

Bovine milk protein preparations (MPPs), namely micellar casein concentrate (MCC), serum protein concentrate (SPC), and MCC with ultrafiltrated buttermilk permeate (MBP), were analyzed as sources of inhibitors of angiotensin-converting enzyme (i.e., ACE) and dipeptidylpeptidase IV (i.e., DPP-IV) as well as antioxidative peptides. The studies involved in silico predictions of the release of biopeptides from bovine milk proteins. Then, all MPPs were subjected to the simulated gastrointestinal digestion using the INFOGEST protocol. Results using a BIOPEP-UWM database tool indicated that 59 biopeptides exhibiting the above-mentioned activities could be produced upon the action of pepsin, trypsin, and chymotrypsin. Thirty-six biopeptides were identified in at least one of the three MPPs subjected to the INFOGEST protocol. MCC before simulated digestion exhibited the strongest ACE-inhibiting activity among all MPPs (IC₅₀ = 1.856 mg/mL). The weakest ACE inhibitory effect was demonstrated for MBP after duodenal digestion (i.e., MBP D; IC₅₀ = 7.627 mg/mL). The above MPP showed the strongest DPP-IV-inhibiting activity (IC₅₀ = 0.0067 mg/mL). All MPPs exhibited antioxidative activity, with the strongest ABTS^•+ (i.e., 2,2′-azino-bis(3-ethylbenzotialozline-6-sulfonic acid) radical scavenging effect shown for MBP D (IC₅₀ = 2.754 mg/mL), and the strongest DPPH^• (i.e., 2,2-diphenyl-β-picrylhydrazyl) radical scavenging activity (IC₅₀ = 1.238 mg/mL) demonstrated for SPC D. Among all MPPs, SPC D also exhibited the highest FRAP (i.e., Ferric Reducing Antioxidant Power) bioactivity (IC₅₀ = 13.720 mg/mL), whereas MBP D was the MPP with the lowest FRAP potential (IC₅₀ = 20.140 mg/mL). The present study results show the potential of all MPPs as functional additives to support health-beneficial functions of dairy products. Full article

To explore the functions of peptides obtained from white mullet (Ophiocephalus argus var. Kimnra) meat, the meat was hydrolyzed via simulated digestion in vitro, and the functions (milk secretion ability, antioxidant activity, angiotensin-converting enzyme (ACE) inhibitory activity, and Fe²⁺ chelation) of the obtained peptide were evaluated. The results indicated that both low-dose and high-dose peptide promoted milk secretion in lactating rats in vivo; the peptides had scavenging effects on free radicals of 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH), 2,2′-azino-bis (3-ethylbenzo-thiazoline-6-sulfonic acid) diammonium salt (ABTS), OH⁻, and O²⁻, and the EC₅₀ concentrations were 55.94 mg/mL, 10.14 mg/mL, 52.92 mg/mL, and 28.53 mg/mL, respectively. The peptides had an inhibitory effect on ACE, and the IC₅₀ concentration was 15.81 mg/mL. The peptides had a chelating ability to Fe²⁺, and the IC₅₀ concentration was 69.05 mg/mL. These results indicate that peptides obtained from white mullet meat exhibit milk secretion-promoting ability, antioxidant activity, ACE-inhibitory activity, and Fe²⁺ chelation, making this an effective approach for isolating specific functional peptides and identifying their sequences from the digested solution of white mullet meat. Full article

Wider availability of marine proteins for the development of food and biomedical applications has a high importance. Sea cucumber body wall proteins have specific functional properties that could be very promising for such product development. However, protein extraction from whole animals is costly and complex, whereas peptide hydrogel production using biotechnological methods can be considered an economically viable approach. Body-wall derived peptides from sea cucumber Parastichopus tremulus have been suggested as a nontraditional source of potentially edible hydrocolloids. In the current work, four peptides were produced through custom synthesis. Scanning electron microscopy (SEM) of the combined mix of the four peptides (1:1 ratio; 15 mM concentration) in a calcium ion-containing buffer confirmed untargeted self-assembly with long, thick fibrillar formations at a microscale (measured mean cross-section 2.78 µm and length sizes of 26.95 µm). The antioxidant activity of the peptides separately, and in combination (1:1 molar ratio), was studied in vitro through ORAC (values in the range from 279 to 543 µmol TE/g peptide), ABTS (from 80.4 to 1215 µmol TE/g peptide), and DPPH (from 5.2 to 19.9 µmol TE/g) assays, and confirmed for protection against oxidation in a Caco-2 cell culture model. Angiotensin-I converting enzyme inhibitory activity was also confirmed for two of the four peptides, with the highest IC 50 of 7.11 ± 0.84 mg/mL. Full article

Bioactive components of abalone and other marine organisms have attracted significant attention owing to their functional performance. The development of peptides with bioactivity like angiotensin-converting enzyme inhibitory (ACEi) and antioxidant properties is of great significance for chronic disease management and drug discovery. In this study, according to the issues of low utilization rate and bioactive content from the hydrolysate of abalone, single-factor and orthogonal experiments were designed to improve the utilization rate of abalone protein, and step hydrolysis with specific proteases was used to improve the overall biological activity of the hydrolysate. A total of 1937 peptide sequences were obtained from the highly bioactive components after separation and peptidomic analysis. Through virtual screening and molecular docking, 14 peptides exhibiting ACEi activity were identified and synthesized for experimental verification, with IC₅₀ values ranging from 0.05 to 0.54 mg/mL. Notably, nine of these peptides were powerful antioxidants. The developed step enzymatic hydrolysis and in silico screening-assisted preparation also provided a feasible and efficient method for exploring more bioactive peptides from diverse biomasses. Full article

The aim of this study was to identify and characterize the bioactive peptide profile of Podolica cow’s milk. This dairy product is known for its nutritional properties related to the presence of peculiar lipids and is a typical breed traditionally reared in southern Italy. Using top-down peptidomics, we identified 2213 peptides in milk samples from four different farms, with 19 matching bioactive sequences. Bioactivities include dipeptidyl peptidase-IV (DPP-IV) inhibition, angiotensin-converting enzyme (ACE) inhibition, antioxidant activity, enhanced calcium uptake, and other peptides with potential antimicrobial effects. DPP-IV-inhibitory peptides (e.g., LDQWLCEKL and VGINYWLAHK) suggest potential for type 2 diabetes management, while ACE inhibitors (such as YLGY and FFVAPFPEVFGK) could support cardiovascular health by reducing hypertension. Antimicrobial peptides such as SDIPNPIGSENSEK and VLNENLLR showed broad spectrum of activity against various harmful microorganisms, positioning Podolica milk as a promising source for natural antimicrobial agents. Additionally, peptides with osteoanabolic, antianxiety, and immunomodulatory properties further highlight the multifaceted health benefits associated with this type of milk. Our findings underline the functional richness of Podolica milk peptides with various bioactivity properties, which could enhance the value of derived dairy products and contribute to sustainable agricultural practices. Future research will aim to explore these bioactivity properties in vivo, establishing a foundation for functional foods and supplements based on Podolica milk. Full article

Background: Hypertension has been identified as a significant risk factor for cardiovascular disease. Given the prevalence of the adverse effects of angiotensin-converting enzyme-inhibitory (ACEI) drugs, natural and effective alternatives to these medications need to be identified. Methods: An investigative study was conducted to assess the ACEI capacity and structural characteristics of enzymatic hydrolysates with varying molecular weights derived from squid skin. The amino acid sequences of the enzymatic digests were analyzed via Nano LC-MS/MS and screened for peptides with ACEI activity using an in silico analysis. Furthermore, molecular docking was employed to investigate the interaction between potential ACEI peptides and ACE. Results: TPSH-V (MW < 1 kDa) exhibited the highest rate of ACEI, a property attributable to its substantial hydrophobic amino acid content. Additionally, TPSH-V exhibited high temperature and pH stability, indicative of regular ordering in its secondary structure. The binding modes of four potential novel ACEI peptides to ACE were predicted via molecular docking with the sequences of FHGLPAK, IIAPPERKY, RGLPAYE, and VPSDVEF, all of which can bind to the ACE active site via hydrogen bonding, with FHGLPAK, RGLPAYE, and VPSDVEF being able to coordinate with Zn²⁺. Conclusions: Squid skin constitutes a viable resource for the production of ACEI peptides. Full article