Search Results (301)

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

Angiotensin-Converting Enzyme (ACE) plays a pivotal role in the renin–angiotensin system, modulating blood pressure and electrolyte homeostasis by deactivating bradykinin and activating angiotensin II. Metabolites from Senecio nutans (1 and 3), a plant indigenous to the Andean region of the Atacama Desert, and their respective oximes, 2 and 4, were subjected to molecular docking analysis, employing six ACE crystal structures. ACE activity assays revealed that oximes exhibited superior inhibitory effects compared to metabolites. Among the compounds investigated, 2 emerged as the most potent ACE inhibitor (2 = 11.5 μM and 4 = 13.4 μM). The vascular contractile response to Angiotensin I showed significant (p < 0.05) reductions in Ang I contraction with 2, 3, and 4 (97 ± 6%, 81 ± 6%, 81 ± 3% compared to control), while 1 exhibited no such effect. These results reinforce the potential of 2 as a promising ACE inhibitor and highlight its impact on vascular contractility. As such, it is a promising candidate for ACE inhibition and hypertension treatment. 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

Tamarillo (Solanum betaceum Cav.) is rich in polyphenols, anthocyanins, and carotenoids, making it a promising candidate for functional food development. This study investigated phytochemical profiles and bioactivities in different tamarillo parts. Various parts of tamarillo were extracted using water and ethanol (0–95%), with 95% ethanol yielding the highest content of bioactive compounds in the peel, pulp, mucilage, and whole fruit, while 75% ethanol was more effective for the seeds. Among tamarillo components, the peel exhibited the highest concentrations of hydroxycinnamoyl derivatives, anthocyanins, and carotenoids, along with superior antioxidant capacity, including strong scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals (EC₅₀, 45.26 µg extract/mL) and high reducing power (EC₅₀, 113.3 µg extract/mL). The peel extract exhibited the strongest inhibitory effects on α-glucosidase (IC₅₀, 1.623 mg/mL) and angiotensin-converting enzymes (IC₅₀, 1.435 mg/mL). In contrast, the pulp extract demonstrated the highest inhibitory activity against pancreatic lipase (IC₅₀, 0.882 mg/mL) and α-amylase (IC₅₀, 2.369 mg/mL). These findings suggest that tamarillo extracts possess potent antioxidant activity and enzyme-inhibitory properties related to metabolic syndrome (MetS). However, gastrointestinal digestion simulation influenced the bioactive compound content and bioactivities. Overall, tamarillo has promising potential as a functional ingredient for MetS prevention, but processing strategies are needed to retain its bioactive properties. 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

Monascus is a fungus widely used in food fermentation. This study employed microbial technology, combined with microscopic morphological observations and ITS sequence analysis, to isolate, purify, and identify 10 strains of red yeast mold from various Monascus products. After the HPLC detection of metabolic products, the M8 strain containing the toxic substance citrinin was excluded. Using the EWM-TOPSIS model, the remaining nine safe Monascus strains were evaluated for their inhibitory activities against pancreatic lipase, α-glucosidase, α-amylase, and the angiotensin-converting enzyme. The M2 strain with the highest comprehensive scores for lowering blood sugar, blood lipids, and blood pressure was selected. Its fermentation product at a concentration of 3 mg/mL had inhibition rates of 96.938%, 81.903%, and 72.215%, respectively. The contents of the blood lipid-lowering active substance Monacolin K and the blood sugar and blood pressure-lowering active substance GABA were 18.078 mg/g and 5.137 mg/g, respectively. This strain can be utilized for the biosynthesis of important active substances such as Monacolin K and GABA, as well as for the fermentation production of safe and effective functional foods to address health issues like high blood lipids, high blood sugar, and high blood pressure in people. This study also provides insights into the use of natural fungi to produce healthy foods for combating chronic diseases in humans. Full article

Hedeoma piperita Benth. (Lamiaceae) is a native medicinal plant from Mexico. It grows in pine, oak, and oyamel forests, as well as grasslands. In the Purépecha Plateau of Michoacán, it is called quiensabe and traditionally used to treat stomach pain, colic, cough, and low blood pressure, among other ailments. This study aimed to determine the phytochemical profile of infusions and ethanolic extracts of the stems and green and purple leaves of H. piperita collected in Cherán, Michoacán. Total phenols, flavonoids, anthocyanins, and terpenoids were analyzed using UV–visible spectrophotometry; specific phenolic acids and flavonoids were detected by high performance thin layer chromatography (HPTLC); and the volatile profile of stems, green and purple leaves was determined by solid phase microextraction in GC-MS. Biological activities such as antioxidant activities (via DPPH and ABTS methods), antihypertensive activities (angiotensin converting enzyme (ACE) inhibition), antibacterial activities (minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC), anti-inflammatory activities (xanthine oxidase enzyme (XOD) inhibition) and antidiabetic activities (α-glucosidase enzyme inhibition) were evaluated in vitro. Results showed key compounds like rosmarinic acid, luteolin, menthone, menthol, and pulegone were identified using HPTLC and SPME/GC-MS, with organ-specific variations. Green and purple leaves infusions inhibited DPPH and ABTS⁺ by 90–99% (IC₅₀ 3.3–3.8 and 7.4–11.5 µg/mL, respectively) and purple leaves infusion showed a 69.88% XOD enzyme inhibition (IC₅₀ 47.991 µg/mL) and an 85.12% α-glucosidase enzyme inhibition (IC₅₀ 72.49 µg/mL). Purple leaves ethanolic extract exhibited the lowest MIC and MBC against Shigella flexneri and ACE inhibition at 97.25% (IC₅₀ 11.19 µg/mL). These results demonstrate the biological potential of H. piperita in the development of natural drugs and expand its use as an herbal remedy. 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

Peptides isolated from various biological materials are potential sources for novel angiotensin-converting enzyme (ACE) inhibitors. Here, the ACE-inhibitory activity of peptides derived from papain-digested hydrolysates of porcine liver and placenta were investigated. A high-throughput method was developed to identify potential bioactive peptides from the hydrolysates using in silico enzymatic cleavage, HPLC-MS/MS, and bioinformatics tools. Four peptides (FWG, MFLG, SDPPLVFVG, and FFNDA) were selected based on their predicted bioactivity, then synthesised and tested for ACE inhibition. All samples demonstrated ACE-inhibitory activity, with FWG and MFLG showing greater potency than SDPPLVFVG and FFNDA. The placenta hydrolysate outperformed both the liver hydrolysate and synthetic peptides in ACE inhibition, possibly due to it containing a higher proportion of dipeptides. The synthetic peptides’ IC50 values were comparable to those reported for porcine muscle-derived peptides in previous studies. While less potent than the commercial ACE inhibitor captopril, the identified peptides showed promising ACE-inhibitory activity. This research demonstrates the potential of porcine liver and placenta as sources of novel ACE-inhibitory peptides and highlights the effectiveness of the developed high-throughput method for identifying bioactive peptides; this method could subsequently be adapted to other peptide sources, facilitating the development of innovative functional foods or nutraceuticals. Full article

Our previous research demonstrated the health benefits of sericin-derived oligopeptides (SDOs) from yellow silk cocoons, particularly their hypoglycemic and antihypertensive properties. This study aims to produce SDOs at a pilot scale, preparing them for large commercial production as a novel food ingredient, and investigates the impact of scale-up on their characteristics and specifications. We compared the productivity of SDOs generated from 25 L and 300 L batches via the hydrolysis of sericin using 5% Neutrase (E/S) at 50 °C for 4 h. The 300 L production scale outperformed the 25 L scale, achieving a hydrolysis degree (DH) of 8.63%, a solid recovery rate of 94.35%, and enhanced inhibitory actions for dipeptidyl peptidase IV (DPP-IV) and angiotensin-converting enzyme (ACE). The characterization of peptides was carried out in ultrafiltered SDOs. Peptides < 3 kDa demonstrated optimal enzyme inhibition and were then fractionated by size exclusion chromatography into nine distinct fractions. Of the nine fractions, F1, F8, and F9 had significant enzyme inhibitory activity. LC-MS/MS analysis revealed 32 unique peptide sequences, with YPDLPYH exhibiting significant dual inhibitory effects on both DPP-IV (IC₅₀ 1.35 mM) and ACE (IC₅₀ 18.10 μM). The maximum residue limit (MRL) for trace metals, pesticide residues, and microbiological contamination in SDOs complies with food regulations. SDOs exhibited stability at 4, 25, and 45 °C for six months, based on their physical characteristics and biological activity. Considering their investigated characteristics, SDOs could be manufactured at a pilot capacity and used as a functional food component in commercial applications designed to improve metabolic health. Full article

This study optimizes the process conditions for preparing angiotensin-converting enzyme (ACE) inhibitory peptides from skimmed goat milk (SGM) hydrolyzed by multi-enzymes using response surface methodology. When the enzymatic hydrolysis time was 90 min, the optimal hydrolysis conditions were a pH of 8.49, enzyme-to-substrate ratio (E/S ratio) of 8.04%, and temperature of 61.54 °C. The hydrolysis degree and ACE inhibitory activity were 65.39% ± 0.01% and 84.65% ± 0.03%, respectively. After purification by ultrafiltration, macroporous resin, and gel filtration, the ACE inhibitory activity of F2-2 in the two components of F2 was higher, with the ACE inhibitory rate of 93.97% ± 0.15% and IC₅₀ of 0.121 ± 0.004 mg/mL. The content of hydrophobic amino acids, fatty amino acids, and aromatic amino acids in component F2-2 accounts for 73.17%, 33.86%, and 33.72%, respectively. Eleven peptides were isolated and identified from the F2-2 components of the enzymatic hydrolysate of SGM, including two peptides without an established database. The peptides mainly came from β casein, α_S1 casein, and α_S2 casein. Full article

Hypertension, type 2 diabetes (T2D), and obesity raise an individual’s risk of suffering from diseases associated with metabolic syndrome (MS). In humans, enzymes that play a role in the prevention and development of MS include angiotensin converting enzyme (ACE-1) associated with hypertension, α-amylase associated with T2D, and lipase linked to the development of obesity. Seaweeds are a rich source of bioactives consisting of proteins/peptides, polysaccharides, and lipids. This study examined the potential of seaweed-derived bioactives from Alaria esculenta, Ulva lactuca, and Palmaria palmata as inhibitors of ACE-1, α-amylase, and lipase. In vitro enzyme inhibitory assays were used to quantify the bioactivity of the seaweed extracts and compare their half-maximal inhibitory (IC₅₀) values to recognised positive control enzyme inhibitory drugs captopril© (an ACE-1 inhibitor), acarbose (an α-amylase inhibitor), and orlistat (a lipase inhibitor). Three seaweed extracts displayed enzyme inhibitory activities equal to, or more effective than, the reference positive control drugs. These were P. palmata peptides (ACE-1 IC₅₀ 94.29 ± 3.07 µg/mL, vs. captopril© 91.83 ± 2.68 µg/mL); A. esculenta polyphenol extract (α-amylase IC₅₀ 147.04 ± 9.72 µg/mL vs. acarbose 185.67 ± 12.48 µg/mL, and lipase IC₅₀ 106.21 ± 6.53 µg/mL vs. orlistat 139.74 ± 9.33 µg/mL); and U. lactuca polysaccharide extract (α-amylase IC₅₀ 168.06 ± 10.53 µg/mL vs. acarbose 185.67 ± 12.48 µg/mL). Proximate analysis also revealed that all three seaweeds were a good source of protein, fibre, and polyunsaturated essential fatty acids (PUFAs). These findings highlight the potential of these seaweeds in the management of diseases associated with MS and as foods. Full article