ACE-inhibitory Activity Research Articles

Characterization of Proteins Extracted from Ulva sp., Padina sp., and Laurencia sp. Macroalgae Using Green Technology: Effect of In Vitro Digestion on Antioxidant and ACE-I Inhibitory Activity.

Macroalgal proteins were extracted from Ulva rigida (URPE) (green), Padina pavonica (PPPE) (brown), and Laurencia obtusa (LOPE) (red) using ultrasound-assisted enzymatic extraction, which is one of the green extraction technologies. Techno-functional, characteristic, and digestibility properties, and biological activities including antioxidant (AOA) and angiotensin-I converting enzyme (ACE-I) inhibitory activities were also investigated. According to the results, the extraction yield (EY) (94.74%) was detected in the extraction of L. obtusa, followed by U. rigida and P. pavonica. PPPE showed the highest ACE-I inhibitory activity before in vitro digestion. In contrast to PPPE, LOPE (20.90 ± 0.00%) and URPE (20.20 ± 0.00%) showed higher ACE-I inhibitory activity after in vitro digestion. The highest total phenolic content (TPC) (77.86 ± 1.00 mg GAE/g) was determined in LOPE. On the other hand, the highest AOACUPRAC (74.69 ± 1.78 mg TE/g) and AOAABTS (251.29 ± 5.0 mg TE/g) were detected in PPPE. After in vitro digestion, LOPE had the highest TPC (22.11 ± 2.18 mg GAE/g), AOACUPRAC (8.41 ± 0.06 mg TE/g), and AOAABTS (88.32 ± 0.65 mg TE/g) (p < 0.05). In vitro protein digestibility of three macroalgal protein extracts ranged from 84.35 ± 2.01% to 94.09 ± 0.00% (p < 0.05). Three macroalgae showed high oil holding capacity (OHC), especially PPPE (410.13 ± 16.37%) (p < 0.05), but they showed minimum foaming and emulsifying properties. The quality of the extracted macroalgal proteins was assessed using FTIR, SDS-PAGE, and DSC analyses. According to our findings, the method applied for macroalgal protein extraction could have a potential the promise of ultrasonication application as an environmentally friendly technology for food industry. Moreover, URPE, PPPE, and LOPE from sustainable sources may be attractive in terms of nourishment for people because of their digestibility, antioxidant properties, and ACE-I inhibitory activities.

Peptidomics comparison of endogenous peptides derived from parent proteins in bovine colostrum and mature milk

Endogenous peptides and proteins are important nutrients in milk and important participants in various biological processes. In the present study, we compared endogenous peptides and parent proteins in bovine milk from different lactation stages using the 4D label-free technique. Endogenous peptides were identified by database search or de novo analysis. Through database searches, we matched 10186 endogenous peptides in bovine milk, which were derived from 1147 parent proteins. By de novo analysis, we identified a total of 1991 endogenous peptides. Among these peptides, 4852 differentially expressed endogenous peptides (DEEPs) between bovine colostrum (BC) and mature milk (BM) were found with various bioactivities, including ACE-inhibitory, immunomodulatory and anticancer activities. Gene Ontology (GO) annotation showed that the differentially expressed parent proteins between BC and BM were mainly in the structural molecule activity category within the molecular function subgroup. The primary Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway was related to ribosomes. These results reveal the changes in the functions and activities of endogenous peptides and parent proteins in bovine milk during lactation and provide novel insight into developing infant formula powder based on bovine sources.

Effects of Roasting and Extrusion Puffing on the Antihypertensive Activity of Blended Grains in Spontaneously Hypertensive Rats

We investigated the effects of processing (roasting and extrusion puffing) on the antihypertensive activity of blended grains both in vitro and in vivo. The blended grains were composed of sorghum (Sorghum bicolor), adzuki bean (Vigna angularis), and finger millet (Eleusine coracana). In the in vitro studies, total phenolic content (TPC), total flavonoid content (TFC), and angiotensin-converting enzyme (ACE) inhibitory activity of blended grains were evaluated. The results showed a significant decreasing trend in TPC, TFC, and ACE inhibitory activity in the following order: nonprocessed blended grains (NPBG) &gt; roasted blended grains (RBG) &gt; extrusion puffed blended grains (EPBG). Spontaneously hypertensive rats (SHRs) were fed a diet containing 40% blended grains (replacing the standard diet) for 8 weeks. None of the blended grains had any effects on feed intake, liver function, and serum lipid profile. Notably, NPBG showed the greatest reduction in systolic blood pressure compared to the model control (MC), followed by RBG, and EPBG, whereas diastolic blood pressure was significantly decreased in NPBG and RBG. Serum ACE activity and angiotensin II levels significantly decreased in all blended grains, with NPBG and RBG showing the most significant decrease in angiotensin II levels. Moreover, the mRNA expression of renin, a hormone involved in hypertension, was significantly decreased in NPBG and RBG. Only NPBG ameliorated aortic vascular remodeling compared to the MC. These results suggest that NPBG exhibited the most potent antihypertensive activity; however, roasting could be an effective processing method for maintaining antihypertensive effects compared to extrusion puffing.

Multifunctional apple seed protein hydrolysates: Impact of enzymolysis on the biochemical, techno-functional and in vitro α-glucosidase, pancreatic lipase and angiotensin-converting enzyme inhibition activities

The work was designed to assess the amelioration effect of papain hydrolysis on the biochemical, techno-functional, and biological properties of apple seed protein isolate (API) after 0–90 min of hydrolysis. Hydrolysis significantly enhanced the nutritional value (protein content ˃ 90 %) while decreasing the average particle size. With increasing hydrolysis time, FTIR analysis revealed a transition from α-helix to β-turn structure, indicating the unfolding of protein structure. This structural alteration positively influenced the functional characteristics, with samples hydrolyzed for 90 min exhibiting excellent solubility, higher water and oil absorption capacity, foaming capacity, and increased emulsifying activity index. Moreover, samples hydrolyzed for 90 min displayed the highest α-glucosidase (29.62–57.43 %), pancreatic lipase inhibition (12.87–31.08 %), and ACE inhibition (25.32–62.70 %) activity. Interestingly, the inhibiting ability of protein hydrolysates against α-glucosidase and ACE was more effective than pancreatic lipase, suggesting their usefulness as a functional ingredient, particularly in type II diabetes and hypertension management.

Identification and quantification of compounds with Angiotensin-converting enzyme inhibitory activity in licorice by UPLC-MS.

Licorice is a famous medicine-food herb for treating cardiovascular diseases in many compound prescriptions. Angiotensin-converting enzyme (ACE) is a key target of cardiovascular diseases. Despite its significance, there is limited scientific investigation regarding the ACE inhibitory effects of licorice. In this study, we used an activity-guided approach with an aggregation-induced emission (AIE) fluorescent probe to identify compounds with ACE-inhibitory activity in licorice. Nine components of licorice were found to have ACE inhibitory activity, in which 46 compounds were identified by using UPLC-QTOF-MS. Seven active compounds were found in this study. Among them, licochalcone B had best ACE inhibitory activity (IC50=0.24μM). Finally, an UPLC-Q-MS method was established to quantify the five major active compounds in three batches of licorice. The findings of this study offer valuable insights into the potential of licorice as a source of ACE inhibitors and its relevance in the development of related products.

Ultrafiltration fractionation of rice protein hydrolysates: Physicochemical properties and potential biological activities of different rice protein hydrolysate fractions

In this study, rice protein hydrolysate (RPH) was separated by membrane ultrafiltration, and three ultrafiltration fractions (UFs) with distinct molecular weights (RPP-1, RPP-2 and RPP-3) were yielded. The physicochemical properties and in vitro bioactivities of these fractions were characterized. Among RPH and its UFs, RPP-1 exhibited highest DPPH radical scavenging activity (IC50 = 4.42 ± 0.08 mg/mL) and ferric reducing antioxidant power (84.21 mg GSH/g). RPP-3 exhibited the highest ABTS radical scavenging activity (IC50 = 0.97 ± 0.01 mg/mL). All the samples exhibited angiotensin converting enzyme inhibitory activity (5.38% ± 0.76%–54.14% ± 3.04%) and α-glucosidase inhibitory activity (−38.90% ± 3.20%–99.99% ± 0.01%). In addition, the activation of alcohol dehydrogenase by RPH and its UFs was observed in this study, with an activation percentage of 46.20% ± 4.96%–199.77% ± 7.71%. However, no inhibitory activity towards acetylcholinesterase was detected. In present study, the potential antialcohol and hepatoprotective activity of RPH was observed. Overall, this study would provide a new idea for the high-value utilization of RPH and a theoretical foundation for the development of bioactivity peptides derived from rice protein.

In silico screening and characterization, inhibition mechanism on ACE, and stability of antihypertensive peptides with Zn-chelating capacity identified from millet bran albumin hydrolysates

To obtain Angiotensin-I-Converting Enzyme (ACE) inhibition peptides with Zn-chelating capacity, millet bran albumin hydrolysates (MBAH) were subjected to Sephadex G-15 gel and reverse phase-high liquid performance chromatography, and UPLC-ESI-MS/MS analysis. Five oligopeptides including Val-Gly-Ser-Asp-Gly-Leu (VGSDGL), Thr-Gly-His-Gly-Val-Ala (TGHGVA), Gly-Cys-His-His-Tyr (GCHHY), Leu-Val-Glu-Ala-Val-Pro-Arg-Gly (LVEAVPRG) and Val-Leu-Ala-Gln-Glu-Glu (VLAQEE) were identified in MBAH. Of these, only pentapeptide GCHHY showed both ACE-inhibitory activity (IC50: 134.78 μmol/L) and Zn-chelating capacity (14.16 mg/g). Molecular docking and inhibition kinetics showed that GCHHY was a competitive inhibitor of ACE, because it could bind with Lys511 of ACE which belongs to the central S2 pocket. Moreover, GCHHY can affect zinc tetrahedral coordination in ACE through binding with Glu411 and His383. The sulfhydryl, amino and carboxyl groups of GCHHY can bind with zinc ions. Under the gastrointestinal digestion, the ACE-inhibitory activity of GCHHY was relatively stable, and the zinc solubility of GCHHY-Zn complexes was more stable than zinc sulfate (P < 0.05). In addition, both GCHHY and GCHHY-Zn complexes lowered the diastolic blood pressure and systolic blood pressure of spontaneous hypertensive rats at dose of 50–200 mg/kg body weight. These results suggested the potential applications of millet albumin peptides as ingredients for antihypertension or zinc fortification.

Prediction and Validation of Proline-containing Tripeptides with Angiotensin I-converting Enzyme Inhibitory Activity Using Machine Learning Models

Background: Numerous inhibitory peptides against angiotensin I-converting enzyme, a target for hypertension treatment, have been found in previous studies. Recently, machine learning screening has been employed to predict unidentified inhibitory peptides using a database of known inhibitory peptides and descriptor data from docking simulations. Objective: The aim of this study is to focus on angiotensin I-converting enzyme inhibitory tripeptides containing proline, to predict novel inhibitory peptides using the machine learning algorithm PyCaret based on their IC50 and descriptors from docking simulations, and to validate the screening method by machine learning by comparing the results with in vitro inhibitory activity studies. Methods: IC50 of known inhibitory peptides were collected from an online database, and descriptor data were summarized by docking simulations. Candidate inhibitory peptides were predicted from these data using the PyCaret. Candidate tripeptides were synthesized by solid-phase synthesis and their inhibitory activity was measured in vitro. Results: Seven novel tripeptides were found from the peptides predicted to have high inhibitory activity by machine learning, and these peptides were synthesized and evaluated for inhibitory activity in vitro. As a result, the proline-containing tripeptide MPA showed high inhibitory activity, with an IC50 value of 8.6 µM. Conclusion: In this study, we identified a proline-containing tripeptide with high ACE inhibitory activity among the candidates predicted by machine learning. This finding indicates that the method of predicting by machine learning is promising for future inhibitory peptide screening efforts.

Bioactive Alkaloids as Secondary Metabolites from Plant Endophytic Aspergillus Genus

Alkaloids represent a large family of natural products with diverse structures and bioactivities. These compounds and their derivatives have been widely used in clinics to treat various diseases. The endophytic Aspergillus is a filamentous fungus renowned for its extraordinary ability to produce active natural products of high therapeutic value and economic importance. This review is the first to focus on Aspergillus-derived alkaloids. Through an extensive literature review and data analysis, 263 alkaloids are categorized according to their structural features into those containing cytochalasans, diketopiperazine alkaloids, quinazoline alkaloids, quinoline alkaloids, indole alkaloids, pyrrolidine alkaloids, and others. These metabolites exhibited diverse biological activities, such as antibacterial activity, cytotoxicity, anti-inflammatory activity, and α-glucosidase, ACE, and DPPH inhibitory activities. The bioactivity, structural diversity, and occurrence of these alkaloids are reviewed in detail.

Active Compounds of Sembung Leaves (Blumea balsamifera DC) in Silico Screening as Antihypertensives

Hypertension is a structural or functional change in the arteries or the organs it supplies caused by increased blood pressure. Angiotensin-converting enzyme (ACE) can increase blood pressure by converting inactive angiotensin I to active (angiotensin II). Captopril is a hypertension drug that can inhibit ACE activity. Sembung leaf (Blumea balsamifera DC) is a plant that can potentially have antihypertensive activity. This study aims to identify the interaction of active compounds in sembung leaves against ACE as antihypertensive drug candidates through an in silico test based on pharmacodynamic and pharmacokinetic parameters using two docking software, Autodock Vina and PyRx. The results showed that Luteolin was the best test ligand besides having lower ΔG and Ki than control ligands and higher Kd than control ligands. Luteolin was identified to interact with Zn and hydrogen bond interactions at the active site and met the criteria in Lipinski analysis, ADME, and toxicity, so this compound is relatively safe to be used as a drug candidate for the treatment of hypertension.

Metabolite profiling of fermented milks as affected by adjunct cultures during long-term storage

The effects of starter strains (Lactiplantibacillus plantarum 156, Lactobacillus casei ATCC 334, Lactobacillus helveticus DPC 4571, and Streptococcus thermophilus 20S4) on the physicochemical and microbiological properties, volatiles, bioactive peptides, and gamma-aminobutyric acid (GABA) contents of fermented milks were evaluated during storage. The use of different adjunct culture combinations had no significant effect on the gross chemical composition. The bacterial strains remained highly viable in the fermented milk during storage. The peptide extracts exhibited a high ACE-inhibitory activity, which was particularly increased in the samples where L. casei ATCC 334 and L. helveticus DPC 4571 strains co-existed. Almost the same levels of antioxidant activity was observed in the peptides extracted from fermented milk. Peptide extracts showed a certain level of antimicrobial activitiy against Staphylococcus aureus ATCC 29213, Listeria monocytogenes ATCC 7644, Salmonella Typhimurium RSHMB 95091, and Escherichia coli O157:H7; however, no inhibitory activity was observed against Bacillus cereus BC 6230. Among the free amino acids, His, Arg, Ala, and Pro were predominant in the samples. Significant differences were observed between samples regarding GABA content, which increased with increasing levels of proteolytic activity. A total of 33 volatile compounds were identified in fermented milks, with acetone, 2,3-butanedione, acetoin, 2-heptanone, acetic and hexanoic acids being the predominant volatiles. These results demonstrate the multifunctional role of peptides and GABA extracted from fermented milk through the action of specific Lactobacillus strains. Therefore, such a functional fermented milk product can be used to reduce the risk of disease or improve specific physiological functions.

Changes in Composition of Some Bioactive Molecules upon Inclusion of Lacticaseibacillus paracasei Probiotic Strains into a Standard Yogurt Starter Culture.

Incorporation of probiotic Lacticaseibacillus paracasei into a standard yogurt starter culture can drastically improve its health promoting properties. However, besides being an advantage in itself, the incorporation of a new probiotic strain can significantly affect the overall composition of fermented milk. In this article, the effect of incorporation of the L. paracasei probiotic strains (KF1 and MA3) into several standard yogurt starter cultures (consisting of the following strains: Streptococcus thermophilus 16t and either Lactobacillus delbrueckii Lb100 or L. delbrueckii Lb200) was investigated. Such parameters as the degree of proteolysis, antioxidant activity, ACE-inhibitory activity, content of organic acids, profile of FAs and profile of volatile organic compounds were measured, and the influence of the starter culture composition on these parameters was described. It was demonstrated that, at least in the case of the studied strains, yogurt with L. paracasei had an advantage over the standard yogurt in terms of the content of acetoin, acetic acid, butyric acid and conjugated linoleic acid. Moreover, the incorporation of L. paracasei KF1 significantly improved the hypotensive properties of the resulting yogurt. Thus, the presented study provides insight into the bioactive molecules of probiotic yogurt and may be useful for both academia and industry in the development of new dairy-based functional products.

Discovery and Characterization of a Dual-Function Peptide Derived from Bitter Gourd Seed Protein Using Two Orthogonal Bioassay-Guided Fractionations Coupled with In Silico Analysis.

The hydrolysate of bitter gourd seed protein, digested by the combined gastrointestinal proteases (BGSP-GPs), exhibited the most potent inhibition on angiotensin-I-converting enzyme (ACE) with an IC50 value of 48.1 ± 2.0 µg/mL. Using two independent bioassay-guided fractionations, fraction F5 from reversed-phase chromatography and fraction S1 from strong cation exchange chromatography exhibited the highest ACE inhibitory (ACEI) activity. Three identical peptides were simultaneously detected from both fractions and, based on the in silico appraisal, APLVSW (AW6) was predicted as a promising ACEI peptide. Their dipeptidyl peptidase-IV (DPP4) inhibitory (DPP4I) activity was also explored. The IC50 values of AW6 against ACE and DPP4 were calculated to be 9.6 ± 0.3 and 145.4 ± 4.4 µM, respectively. The inhibitory kinetics and intermolecular interaction studies suggested that AW6 is an ACE competitive inhibitor and a DPP4 non-competitive inhibitor. The quantities of AW6 in BGSP-GP hydrolysate, fractions F5 and S1, were also analyzed using liquid chromatography-tandem mass spectrometry. Notably, AW6 could resist hydrolysis in the human gastrointestinal tract according to the result of the simulated gastrointestinal digestion. To the best of our knowledge, this is the first discovery and characterization of a dual-function (ACEI and DPP4I activities) peptide derived from bitter gourd seed protein.

Angiotensin-converting enzyme inhibitory peptide IVGFPAYGH protects against liver injury in mice fed a high‑sodium diet by inhibiting the RAS and remodeling gut microbial communities

Consuming a high‑sodium diet carries serious health risks and significantly influences the activation state of the renin-angiotensin system (RAS). This study evaluates the protective effect of angiotensin-converting enzyme (ACE) inhibitory peptide IVGFPAYGH on a high‑sodium diet–induced liver injury. IVGFPAYGH supplementation increased the activities of liver antioxidase and decreased the levels of liver inflammatory factor in mice fed a high‑sodium diet (8 % NaCl). IVGFPAYGH supplementation also reduced liver fatty acid synthesis and promoted fatty acid oxidation, increased the expression of low-density lipoprotein receptor, and improved liver dyslipidemia. Furthermore, IVGFPAYGH supplementation inhibited the activation of the liver RAS via inhibiting ACE activity and reducing angiotensin II levels in mice fed a high‑sodium diet. Moreover, IVGFPAYGH supplementation could alter the gut microbiota composition toward a normal gut microbiota composition and increase the abundance of the Lactobacillus genus. IVGFPAYGH supplementation also increased the expression levels of small intestinal tight junction protein and cecum short-chain fatty acids. Thus, IVGFPAYGH supplementation may maintain intestinal homeostasis and improve high‑sodium diet–induced liver injury by altering the gut microbiota composition and inhibiting the RAS. IVGFPAYGH is a promising functional ingredient for protecting liver damage caused by a high‑sodium diet.

The effect of probiotic strains on the proteolytic activity and peptide profiles of lupin oat-based yoghurt

Plant-based yoghurt is on the rise, addressing both sustainability and innovation in food production. The macro-molecular changes driven by bacterial strains during fermentation of plant-based yoghurt leading to diverse nutritional functionality, however, is overlooked. Here, the lupin-oat milk yoghurt was developed using three distinctive commercial starter cultures composed of Lactobacillus delbrueckii sub bulgaricus, Streptococcus thermophilus and Lactobacillus rhamnosus for yoghurt 1 (Y1), Lactobacillus delbrueckii sub bulgaricus, Streptococcus thermophilus and Lactobacillus paracasei for yoghurt 2 (Y2), Lactobacillus plantarum and Bifidobacterium sps for yoghurt 3 (Y3). The post-acidification, proteolytic activity, amino acid composition, cell viability, peptide profile and angiotensin-converting enzyme (ACE) inhibitory activity were investigated during seven days of refrigeration at 4 °C. Gel electrophoresis and size exclusion chromatography (SEC) of yoghurts, showed substantial degradation of proteins into low molecular weight protein fractions (45, 55 and 75 kDa) which are complemented by an increase in small polypeptides with a molecular weight of <20 kDa. The bacteria did not fully utilize the released peptides, leading to significant accumulations in the medium. This observation indicates the potential presence of bioactive compounds with beneficial effects. The SEC peak fraction containing a smaller peptide size ranging from 0.059 to 0.87 kDa showed better ACE inhibitory activity. A comprehensive analysis of peptide profiling of the yoghurts was done using Nano UPLC-MS/MS which showed co-cultures promoted the formation of peptides. After undergoing bacterial fermentation, the number and types of peptides followed the Y3>Y1>Y2 sequence. This study emphasizes the potential of lupin-oat yoghurts peptides as a functional component.

Study of the Physiochemical and Nutraceutical Properties of Sour and Sweet Pomegranate Juice in Northern Jordan

Pomegranate juice (PJ) is the major pomegranate product that offers a simple way to consume pomegranate’s biologically active compounds, obtained from arils. In this study, we objectively investigate the physiochemical properties such as pH value, total soluble solids, color parameters, fructose and glucose contents, hydroxymethyl furfural (HMF) content, and viscosity. Also, the phytochemical content includes total phenols content, antioxidant activity, flavonoid, anthocyanin content, and phenolic quantification. In addition, the alpha-amylase and angiotensin-converting enzyme inhibitory activities among sweet and sour varieties of pomegranate juice obtained from different regions in Northern Jordan (Ajloun, Dair Abi Said, and Kufur Soum) where the significant differences at P ≤ 0.05 appeared among sweet and sour varieties in different pomegranate juice samples. The pH values for pomegranate juice range from 2.87 to 3.77, and TSS ranges from 15.36 to 16.9 Brix. The total phenol content of pomegranate juice ranged from 105.8 to 238.63 mg/g while the total flavonoid content was present in the range of 135.53–184.9 mg/g. The DPPH inhibition (%) of pomegranate juice ranged between 20.66% and 50.63%, and the anthocyanin content range was 3.66–11.02 mg/g. Ellagic acid, delphinidin, 3,4-dihydroxyphenethyl alcohol, 2-hydroxyphenethyl alcohol, catechin, epicatechin, vanillic acid, caffeic acid, P-coumaric acid, chlorogenic acid, gallic acid, ferulic acid, and syringic acid are phenolics present predominantly in pomegranate juice. Pomegranate juice exhibits high alpha-amylase and angiotensin-converting enzyme inhibition activity. All results indicate good quality and health properties for pomegranate juice.

A novel alcalase-hydrolyzed soybean meal hydrolysates prepared using by-product material: Structure, function property, sensory property, and biological activity

This work investigated the effects of different hydrolysis times (0.5, 1 and 2 h) on the structure, interface and sensory properties, and biological activity of soybean meal peptides obtained by alcalase protease hydrolysis. After hydrolyzation, the molecular weight of soybean meal hydrolysates (SMHs) was below 10 kDa. An increase in the number of β-turns and a decrease in α-helices suggested the unfolding of soybean meal proteins. The ultraviolet absorption and fluorescence intensities of SMHs increased, suggesting an increase in the content of free amino acids, which likely contributed to the biological activity of SMHs. Additionally, after hydrolyzation for 1 h, the SMHs showed the highest antioxidant and ACE inhibitory activity. LC-MS/MS-based peptidomics analysis showed 101 differential peptides in hydrolysates among different hydrolysis times with reliable potential biological activities. However, the emulsification of the SMHs decreased due to the exposure of hydrophilic amino acids. All in all, hydrolysis time is a factor that influences the peptide sequence and properties, resulting in different antioxidant and ACE inhibitory activities.

ACE inhibitory peptides from enzymatic hydrolysate of fermented black sesame seed: Random forest-based optimization, screening, and molecular docking analysis

In this study, black sesame seeds were fermented by Lactobacillus Plantarum NCU116 and then hydrolyzed using acid protease to improve Angiotensin-I-converting enzyme (ACE) inhibitory activity. The random forest-particle swarm optimization (RF-PSO) model was applied to predict the ACE inhibitory activity during the hydrolysis process based on the experimental data. After separating by adsorption chromatography, gel filtration chromatography, and reversed phased-high performance liquid chromatography and then screening in silico method, eight peptides were identified from fermented black sesame seed hydrolysates as ITAPHW, SLPNYHPSPR, QYLPR, IRPNGL, YHNAPIL, LSYPR, GFAGDDAPRA, and LDPNPRSF with IC50 values of 51.69 μM, 146.67 μM, 655.02 μM, 752.60 μM, 1.02 mM, 2.01 mM, 1.97 mM, and 3.43 mM, respectively. ITAPHW and SLPNYHPSPR exhibited high antioxidant activity and inhibited the ACE activity in a non-competitive pattern. Molecular docking revealed that the strong ACE inhibition of ITAPHW and SLPNYHPSPR is probably attributed to the interaction with Zn2+ of ACE.

Physicochemical properties, biological activities, and peptidome profile of grass carp swim bladder collagen hydrolysates

This study investigated the physicochemical properties and biological activities of hydrolysates derived from grass carp swim bladder collagen through enzymatic hydrolysis using Papain, Alcalase, Flavourzyme, and Neutrase. The results indicated that the select of protease significantly influences the degree of hydrolysis (DH), molecular weight distribution (MW), trichloroacetic acid-nitrogen solubility index (TCA-NSI), structure, and bioactivities of the hydrolysates. The hydrolysate of Alcalase (HA) exhibited the highest DH, TCA-NSI, Fe2+ chelating activity, 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity, and angiotensin-converting enzyme (ACE) inhibitory activity. Pearson's correlation and principal component analysis (PCA) revealed strong interrelationships among the DH, TCA-NSI, β-sheet content, Fe2+ chelating activity, ACE inhibitory activity, and short peptide content within the hydrolysates (|r| > 0.80, P < 0.05). A total of 524 peptides were identified from HA, and 20 novel peptides with no toxicity, no allergenicity, and potential bioactivity were discovered by in silico strategy. Molecular docking analysis revealed that hydrophobic interactions and hydrogen bonds were the primary interaction forces between the peptides with free radicals and ACE. These findings provide a foundation for the high-value utilization of grass carp swim bladder hydrolysates as bioactive peptides in the food industry, enabling the sustainable utilization of freshwater swim bladder by-products.

Amino acid composition and angiotensin-i converting enzyme inhibitory activity of Cowpea (&lt;i&gt;Vigna unguiculata&lt;/i&gt;) pepsin-pancreatin protein hydrolysate fractions

Legumes are high in protein and have been linked to the management and prevention of chronic diseases due to their bioactive components. This study investigated the amino acid composition of cowpea protein hydrolysate and its inhibitory impact on angiotensin-I converting enzyme (ACE-I). Cowpea (Vigna unguiculata) protein hydrolysate (CPH) was produced through sequential digestion with pepsin and pancreatin. CPH was then separated using G-50 gel filtration chromatography and reverse phase high performance liquid chromatography (RP-HPLC). The fractions' ACE-I inhibitory activity was then assessed. The IC50 value for the RP-HPLC fraction with the highest ACE-I inhibitory activity (P&lt;0.05) was 6.23 μg/mL. The amino acid profile revealed that a large proportion of hydrophobic amino acids were present in the RP-HPLC fraction containing the peptide with the highest ACE-I inhibitory activity. These findings suggest that CPH has the potential to be employed in the development of functional foods that can aid in the prevention and treatment of hypertension.