ACE-inhibitory Activity Research Articles

Potential blood pressure regulatory effect of low molecular weight α-chymotrypsin extract and its peptides from Stichopus japonicus: Peptide-ACE interaction study via in silico molecular docking

Hypertension is a significant risk factor for cardiovascular disease and heart damage. Stichopus japonicus (S. japonicus) is a red sea cucumber with antioxidant and anti-hypertensive activities. However, its anti-hypertensive mechanism remains unclear. In this study, we evaluated the inhibitory effects of angiotensin-converting enzyme (ACE) of α-chymotrypsin-assisted hydrolysate of S. japonicus (α-chy) and its ultrafiltrate fractions (>10 kDa [α-chy-I], 5–10 kDa [α-chy-II], and <5 kDa [α-chy-III]). Low molecular α-chy-III exerted excellent ACE inhibitory and anti-hypertensive activities in spontaneously hypertensive rats (SHR). Moreover, α-chy-III significantly reduced the systolic and diastolic blood pressure by modulating the serum angiotensin and ACE levels. Histological analysis revealed that α-chy-III markedly protected the aorta, heart, and kidney tissues of SHR from hypertension-induced tissue damage.Taken together, our findings highlight the potential of α-chy-III as a functional food ingredient for the treatment of hypertension and its comorbidities.

DeepBP: Ensemble deep learning strategy for bioactive peptide prediction.

Bioactive peptides are important bioactive molecules composed of short-chain amino acids that play various crucial roles in the body, such as regulating physiological processes and promoting immune responses and antibacterial effects. Due to their significance, bioactive peptides have broad application potential in drug development, food science, and biotechnology. Among them, understanding their biological mechanisms will contribute to new ideas for drug discovery and disease treatment. This study employs generative adversarial capsule networks (CapsuleGAN), gated recurrent units (GRU), and convolutional neural networks (CNN) as base classifiers to achieve ensemble learning through voting methods, which not only obtains high-precision prediction results on the angiotensin-converting enzyme (ACE) inhibitory peptides dataset and the anticancer peptides (ACP) dataset but also demonstrates effective model performance. For this method, we first utilized the protein language model-evolutionary scale modeling (ESM-2)-to extract relevant features for the ACE inhibitory peptides and ACP datasets. Following feature extraction, we trained three deep learning models-CapsuleGAN, GRU, and CNN-while continuously adjusting the model parameters throughout the training process. Finally, during the voting stage, different weights were assigned to the models based on their prediction accuracy, allowing full utilization of the model's performance. Experimental results show that on the ACE inhibitory peptide dataset, the balanced accuracy is 0.926, the Matthews correlation coefficient (MCC) is 0.831, and the area under the curve is 0.966; on the ACP dataset, the accuracy (ACC) is 0.779, and the MCC is 0.558. The experimental results on both datasets are superior to existing methods, demonstrating the effectiveness of the experimental approach. In this study, CapsuleGAN, GRU, and CNN were successfully employed as base classifiers to implement ensemble learning, which not only achieved good results in the prediction of two datasets but also surpassed existing methods. The ability to predict peptides with strong ACE inhibitory activity and ACPs more accurately and quickly is significant, and this work provides valuable insights for predicting other functional peptides. The source code and dataset for this experiment are publicly available at https://github.com/Zhou-Jianren/bioactive-peptides .

Untargeted metabolomics profiling for revealing water-soluble bioactive components and biological activities in edible bird’s nest

Edible bird’s nest (EBN) is a functional food renowned for its numerous health benefits. While its nutritional and therapeutic value is well-documented, the metabolites contributing to the bioactivities of EBN remain poorly understood. This study aimed to identify the metabolites present in EBN subjected to different treatments, including double-boiled EBN (EBNdb), EBN hydrolysate (EBNhydro), EBN fermented with Lactobacillus helveticus (EBNLH), Latilactobacillus curvatus (EBNLC), and Latilactobacillus sakei (EBNLS) using liquid chromatography-mass spectrometry (LC-MS) and correlate the identified bioactive metabolites with the bioactivities of EBN. It was found that the fermented EBNs exhibited the highest number of metabolites, with 76 tentatively identified, followed by EBNhydro (45) and EBNdb (37). Citric acid (1.97–4.48 g/kg) was present in all treated EBN samples, while L(+)-lactic acid (3.03–8.07 g/kg) and adipic acid (2.33–3.18 g/kg) were only found in fermented EBNs. Among the treated EBN samples, EBNLC demonstrated the significantly highest (p ≤ 0.05) antioxidative (22.34 ± 0.41 % 1,1-diphenyl-2-picrylhydrazil radical scavenging activity), antihypertensive (5.46 ± 0.26 % angiotensin-converting enzyme inhibitory activity), and antihyperglycemic activities (6.48 ± 0.34 % α-amylase inhibitory activity). A total of 18 metabolites, including citric acid, 4-sphingenin, N-acetylcitrulline, 4-aminophenol, L(+)-lactic acid, 2-oxoadipate, sildenafil, formylglycinamidin-RP, 11β,17α,21-α-5β-pregnane-3,20-dione, 2-ketobutyric acid, homoserine, benzaldehyde, 1-pyrroline4-hydroxy-2-carboxylate, nortriptyline, 1-methylguanine, 3-hydroxy-trimethyllysine, 3-phenylpropionate, and reserphine were predicted as bioactive metabolites using the partial least squares discriminant analysis (PLS-DA). This study provides valuable insights into the metabolites present in EBN and serves as fundamental data for future investigations into the bioactive compounds responsible for its specific health benefits, potentially leading to the development of enhanced EBN-based functional foods.

Microencapsulation of Hibiscus sabdariffa extract in taro starch: Determination of optimal conditions of bioactive compound retention using response surface methodology

Hibiscus sabdariffa (HS) extract contains a large amount of bioactive compounds with antioxidant, anticarcinogenic, and antihypertensive effects. The extraction of total phenols, flavonoids, and anthocyanins is more efficient at boiling temperature (~91 °C) than that performed at room temperature (~27 °C). In this study, a central composite rotatable design (CCRD) was used to optimize the inlet temperature conditions of a spray dryer and the concentration of taro starch solids to obtain microcapsules with the highest retention of bioactive compounds in hibiscus extracts. Optimized microcapsules (OM) were obtained at an inlet temperature of 118 °C and solid concentration of 26.5 %. Low moisture content (4.54 %) and water activity (0.2) and high content of total phenols (3374.91 mg GAE/100 g), flavonoids (372.81 mg QE/100 g), monomeric anthocyanins (36.74 mg C-3-GE/100 g), and angiotensin-converting enzyme inhibitory activity (80.01 %), were determined in OM using response surface methodology. OM showed a range of spherical agglomerate sizes (10––32 μm). These results indicate that CCRD is a good tool for establishing the optimal conditions for solid concentration and drying temperature to maximize the protection of bioactive compounds using taro starch as the wall material.

Predicting variable-length ACE inhibitory peptides based on graph convolutional network

Traditional molecular descriptors have contributed to the prediction of angiotensin I-converting enzyme (ACE) inhibitory peptides, but they often fall short in capturing the complex structure of the molecule. To address these limitations, this study introduces molecular graphs as an advanced method for peptide characterization. Peptides containing 2–10 amino acids were represented using molecular graphs, and a graph convolutional network (GCN) model was constructed to predict variable-length peptides. This model was compared with machine learning (ML) models based on molecular descriptors, including Random Forest (RF), Support Vector Machine (SVM), and k-Nearest Neighbor (kNN), under the same benchmark. Notably, the GCN model outperformed the other models with an accuracy of 0.78, effectively identifying ACE inhibitory potential. Furthermore, the GCN model also demonstrated superior performance, exceeding existing methods with an accuracy rate of over 98 % on an independent test set. To validate our predictions, we synthesized peptides VAPE and AQQKEP with high predicted probabilities, and their IC50 values of 2.25 ± 0.11 and 3.75 ± 0.17 μM, respectively, indicating potent ACE inhibitory activity. The developed GCN model presents a powerful tool for the rapid screening and identification of ACE inhibitory peptides, offering promising opportunities for developing antihypertensive components in functional foods.

Effects of fig and pineapple powder on metabolite compounds and health-promoting properties in fermented goat meat sausage.

The objective of this research was to identify the metabolite compounds and health-promoting properties of goat meat fermented sausages containing different amounts of fig and pineapple powder (0.1%, 0.25%, and 0.5%), which are presented by F1, F2, F3 and P1, P2, P3, separately. Fermented sausages were manufactured from the lean meat of female goats. The samples extracted from the goat meat fermented sausages were evaluated for their metabolite compounds, antioxidants, and angiotensin-converting enzyme inhibitory activity. The results showed that the diphenyl picrylhydrazyl radical scavenging activity, azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity, and angiotensin-converting enzyme inhibitory activity were the highest in F3 (p<0.05), whereas the hydroxyl radical (°OH) scavenging capacity was the highest in P3 (p<0.05). In addition, F3 and F2 showed the highest superoxide anion radical scavenging activity (p<0.05), whereas F3 and P3 showed the highest copper chelating activity (p<0.05). Based on the metabolite compounds, hydrophobic amino acids, aromatic amino acids, and bitter amino acids were abundant in F3. Both F3 and P3 contained high concentrations of umami-producing compounds. The incorporation of 0.5% fig powder into goat meat fermented sausage showed improved biological activities based on metabolite compounds.

Identification of Structure-Linked Activity on Bioactive Peptides from Sea Cucumber (Stichopus japonicus): A Compressive In Silico/In Vitro Study.

A sea cucumber (Stichopus japonicus) is an invertebrate rich in high-quality protein peptides that inhabits the coastal seas around East Asian countries. Such bioactive peptides can be utilized in targeted disease therapies and practical applications in the nutraceutical industry. Bioactive peptides were isolated from Stichopus japonicus through ultrafiltration and Sephadex G-10 size exclusion chromatography. The low-molecular-weight fraction (ACSH-III) showed the highest hydroxyl radical scavenging and angiotensin-converting enzyme (ACE) inhibitory activities. Subsequent purification of ACSH-III resulted in four fractions, of which ACSH-III-F3 and ACSH-III-F4 exhibited significant bioactivity. Peptides identified in these fractions, including Phenylalanine-Proline-Threonine-Tyrosine (FPTY) and Tyrosine-Proline-Serine-Tyrosine-Proline-Serine (YPSYPS), were characterized using high-performance liquid chromatography (HPLC) and quadrupole time-of-flight mass spectrometry (QTOF-MS). FPTY demonstrated the most potent antioxidant and antihypertensive activities among these peptides, with IC50 values of 0.11 ± 0.01 mg/mL for hydroxyl radicals and 0.03 ± 0.01 mg/mL for ACE inhibition. Docking simulations revealed strong binding affinities of these peptides to the active site of the ACE, with FPTY displaying interactions similar to those of the synthetic inhibitor lisinopril. These findings suggest that the identified peptides, particularly FPTY, have potential applications as natural antioxidants and functional foods.

Research on the Synergistic Inhibition of Angiotensin-Converting Enzyme (ACE) by the Gastrointestinal Digestion Products of the ACE Inhibitory Peptide FPPDVA.

To gain a deeper understanding of the ACE inhibition effect, the inhibitory effect of ACE-inhibiting peptide (ACEIP) FPPDVA's digestive products on ACE was further investigated. Two novel peptides, PD (IC50 = 161.1 ± 1.10 μM) and DV (IC50 = 66.51 ± 0.99 μM) were identified in the digestive products of FPPDVA using LC-MS/MS. The Peptide Mix (FPPDVA, PD, and DV) exhibited a remarkable synergistic effect on ACE inhibition by significantly enhancing it by up to 508% compared to the individual peptides alone. Furthermore, theoretical simulations suggest that the Peptide Mix synergistically inhibits ACE activity by forming more stable complexes with the active site of ACE, facilitated by an increased number of hydrogen bonds. Additionally, Lineweaver-Burk plot analysis and spectroscopic studies further verified the presence of these stable complexes. ITC results show that the combination of Peptides Mix and ACE is a spontaneous exothermic process driven by entropy. The study showed that FPPDVA has a stronger inhibitory effect on ACE after digestion, making it suitable as an antihypertensive peptide in functional foods.

The Antioxidant Effects of Trypsin-Hydrolysate Derived from Abalone Viscera and Fishery By-Products, and the Angiotensin-I Converting Enzyme (ACE) Inhibitory Activity of Its Purified Bioactive Peptides.

Abalone is a rich source of nutrition, the viscera of which are discarded as by-product during processing. This study explored the biological activities of peptides derived from abalone viscera (AV). Trypsin-hydrolysate of AV (TAV) was purified into three fractions using a Sephadex G-10 column. Nine bioactive peptides (VAR, NYER, LGPY, VTPGLQY, QFPVGR, LGEW, QLQFPVGR, LDW, and NLGEW) derived from TAV-F2 were sequenced. LGPY, VTPGLQY, LGEW, LDW, and NLGEW exhibited antioxidant properties, with IC50 values of 0.213, 0.297, 0.289, 0.363, and 0.303 mg/mL, respectively. In vitro analysis determined that the peptides VAR, NYER, VTPGLQY, QFPVGR, LGEW, QLQFPVGR, and NLGEW inhibited ACE, with IC50 values of 0.104, 0.107, 0.023, 0.023, 0.165, 0.004, and 0.146 mg/mL, respectively. The binding interactions of ACE-bioactive peptide complexes were investigated using docking analysis with the ZDCOK server. VTPGLQT interacted with HIS513 and TYR523, and QLQFPVGR interacted with HIS353, ALA354, GLU384, HIS513, and TYR523, contributing to the inhibition of ACE activity. They also interacted with amino acids that contribute to stability by binding to zinc ions. QFPVGR may form complexes with ACE surface sites, suggesting indirect inhibition. These results indicate that AV is a potential source of bioactive peptides with dual antioxidant and anti-hypertensive dual effects.

Anti-hypertensive, anti-inflammatory, glycemic and satiety impact of cocoa flavoured soy-based powder drink mix enriched with bioactive hydrolysates from nests of Aerodramus fuciphagus

Abstract Objectives The edible bird’s nest hydrolysates (EBNH) are renowned for their health benefits. The study aimed to determine their contributory functional effect as an ingredient in the cocoa-flavoured soy-based powder drink mix (PDM). The product’s glycemic and satiety impact were also studied. Materials and Methods The product was enriched with a reasonably low amount of spray-dried EBNH. The product’s functional effect with respect to in vitro angiotensin converting enzyme (ACE) inhibitory activity and human red blood cells membrane stabilization (RBCMS) activity were evaluated, using its water extract (90 - 95 oC). The glycemic and satiety impact were evaluated using 12 and 30 subjects, respectively, who consumed 250 mL of the product, containing 25 g of available carbohydrates. Results The enriched PDM’s ACE inhibitory activity and RBCMS activity were significantly higher (p&amp;lt;0.05) than those that were devoid of EBNH. A 240 mL (12.5% w/v) of PDM (containing by weight 3.0% EBNH, 75.44% soybean powder, 20% cocoa powder, 0.5% xanthan gum, 1.0% silicon dioxide and 0.06% sucralose) provides about 3.7 kcal/g energy. Its 250 mL meal (consistency index of 14.17 Pa.sn) is high in protein and dietary fiber. The product’s glycemic index (GI) and glycemic load (GL) are low, 24 and 6.0, respectively, raising a normal level of 2 hours postprandial blood glucose (&amp;lt;6 mmol/L) and satisfies hunger for about 2.5 hours. Conclusion The EBNH, as an ingredient, enhances the PDM’s anti-hypertensive and anti-inflammatory properties. The overall findings suggest that the formulated PDM is a wellness food product capable of promoting good human health, including for dieters and individuals with diabetes.

ACE inhibitory effect and saltiness-enhancing properties of chicken-derived umami peptides: Digestive stability, inhibition kinetics, multiple ligand docking and central composite design

Angiotensin-I-converting enzyme (ACE) inhibitory activity and saltiness-enhancing properties of chicken-derived umami peptides were investigated. DGGRYY and NEFGYSNR were screened and the IC50 values were 28.71 μM and 283.24 μM, indicating their potential as novel ACE inhibitors. DGGRYY and NEFGYSNR have good pH and thermal stability. After gastrointestinal digestion, the ACE-inhibitory activity of DGGRYY retained about 53 %, whereas NEFGYSNR retained about 57 %. The inhibition pattern of both peptides was determined to be uncompetitive, consisting with the result of multiple ligand docking that the binding sites were outside the ACE active pocket. Trp59, Tyr62, Asp121, Arg124, and Ser516 were the key binding sites that contributed to the total binding energy. In addition, saltiness and palatability models were established according to sensory analysis and central composite design. In 0.1 % ~ 0.3 % NaCl solutions, the addition of DGGRYY and NEFGYSNR could enhance the salty intensity and compensate for the palatability loss caused by salt reduction.

The profile of plant bioactive compounds in Xinjiang, China unifloral safflower honey and their inhibitory on ACE, and determination of the mechanism of inhibition

Investigating the plant bioactive compounds in unifloral safflower honey from Xinjiang, China, is helpful for verifying its botanical origin and evaluating its functional properties. Therefore, this study quantifying hydroxysafflor yellow A (HSYA), anhydroxysafflor yellow B (ASYB), quercetin, kaempferol, rutin, myricetin, hyperoside, gallic acid, quinic acid, and ferulic acid in safflower honey by high-performance liquid chromatography; HSYA and ASYB accounted for 16.12–28.83% and 13.63–33.09%, respectively, of the quantified plant bioactive compounds and were considered characteristic markers for authentication. These compounds also exhibit angiotensin converting enzyme (ACE) inhibitory activity; the IC50 ranges from 13.33 to 132.45 μmol L−1, and the inhibition constant (Ki) is between 17.13 and 121.34 μmol L−1. HSYA (IC50 = 20.24 μmol L−1, Ki = 19.63 μmol L−1) and ASYB (IC50 = 19.33 μmol L−1, Ki = 17.13 μmol L−1) exhibited the strongest inhibitory effects. Molecular simulation studies have shown that these bioactive compounds bind key residues in the active pocket of ACE through hydrogen bonding and hydrophobic interactions, leading to ACE inhibition. Overall, HSYA and ASYB could be considered bioactive chemical markers for verifying the botanical origin of Xinjiang, China, unifloral safflower honey, and safflower honey may be a potential functional food by inhibiting ACE.

Integrative approach to assessing bioactivity from hempseed protein isolate extracted and dehydrated by different methods: Synergising in silico prediction and in vitro validation

This study demonstrated a comprehensive workflow combining in silico screening and prediction with in vitro validation to investigate the bioactivity of hempseed protein isolate (HPI) extracted and dehydrated using different methods. By adopting an in silico approach, 13 major proteins of HPI were hydrolysed by 20 selected enzymes, leading to the prediction of 20 potential bioactivities. With papain hydrolysis, dipeptidyl peptidase-IV (DPP4) and angiotensin-converting enzyme (ACE) inhibitory activities emerged as having the highest potential. In vitro experiments confirmed these predictions, with DPP4 and ACE inhibitory activities displaying IC50 values of 0.32–0.42 mg/mL and 6.8–9.17 μg/mL, respectively. A strong correlation (r2 = 0.96) was observed between in vitro protein inhibitory results and in silico predicted data. This study demonstrated an effective integrative approach for predicting bioactive peptides in food protein, providing valuable guidance on its processing to create value-added products.

Protein-added kefir: biochemical changes in in vitro digestion stages.

While yogurt is the leading fermented milk product, kefir is at the top of the beverage scale. Milk proteins, on the other hand, show specific functions that positively affect healthy nutrition due to the bioactive components, that they provide the necessary amino acids for growth and development. In our study, kefir, a functional product enriched with whey proteins, casein and skimmed milk powder, which are the natural components of milk, was produced. Added-protein kefir samples were applied the in vitro digestion protocol, static method. In order to observe different protein behaviors, samples were taken pre-digestion, at 120th minute and at 240th minute of digestion protocol. ACE and Antioxidant capacity determination analyzes were carried out. While ACE inhibition values were in the range of 78.63-90.30% pre-digestion, they changed in the range of 86.97-96.38% after gastrointestinal digestion. It was determined that the ACE inhibition values of the control sample remained at the lowest level at all stages of digestion and that the difference between all of samples was significant (P < 0.05). Antioxidant activity value ranging from 0.3615-0.5512 meq Ascorbic acid/μg before digestion was determined as 1.3796-1.9313 meq Ascorbic acid/μg after gastrointestinal digestion (P < 0.05). Kefir samples containing whey protein stand out with their high potential in terms of both antioxidant activity capacity and ACE inhibition activity at all stages of digestion. Considering their therapeutic effects in fermented products, it is thought that whey proteins among milk proteins will be important alternative sources to enrich the protein content in kefir production. © 2024 Society of Chemical Industry.

Multifunctional properties of peptides derived from black cricket (Gryllus assimilis) and effects of in vitro digestion simulation on their bioactivities

Insects are a rich source of proteins and are produced in systems that have lower environmental impact. As an alternative protein source, they can be consumed directly or used as an ingredient in other formulations. Recently, there has been growing interest in utilizing insect proteins as a substrate to obtain bioactive peptides as well as in investigating the maintenance of their biological properties under physiological conditions. This study aimed to evaluate the impact of simulated digestion on the bioactive properties of protein hydrolysates from black crickets (Gryllus assimilis). Following simulated digestion of the hydrolysate obtained through the application of Flavourzyme, the scavenging activities of ABTS and DPPH radicals, and ferric reducing antioxidant power (FRAP) increased by approximately 17 %, 246 %, and 173 %, respectively. For the hydrolysate obtained using the binary combination of Flavourzyme/Neutrase, the inhibitory activities of α-amylase and α-glucosidase after digestion were 47.87 % and 12.73 %, respectively, not significantly (p > 0.05) different from non-digested hydrolysates. The angiotensin-converting enzyme (ACE) inhibitory activity of the sample hydrolyzed with Flavourzyme/Alcalase proteases was 42.22 %, but this property was completely lost after in vitro digestion. Untargeted proteomic analysis allowed the identification of 22 peptides in the <3 kDa fraction of the digested black cricket protein. The LPPLP sequence was considered potentially bioactive for all activities tested in silico.

Walnut peptide relieves hypertension and associated kidney and heart injury by regulating the renin-angiotensin-aldosterone system and intestinal microbiota.

Hypertension is a chronic disease with high morbidity and mortality. Previously, we screened a walnut meal peptide FDWLR (PEP) with significant angiotensin-converting enzyme inhibitory activity. The present study further investigated the anti-hypertensive effects of PEP in vivo using spontaneously hypertensive rats. The results indicated that PEP reduced blood pressure and the indices in the renin-angiotensin-aldosterone system (RAAS) including angiotensin-converting enzyme (ACE) (decreased by 15.36%), angiotensin II (Ang II) (decreased by 31.56%), angiotensinogen (AGT) (decreased by 58.84%) and aldosterone (ALD) (decreased by 18.27%), whereas NO levels increased by 54.96%. The pathological analysis showed that PEP relieved cardiac and renal damage. PEP also alleviated oxidative stress, inflammation and fibrosis in the heart and kidney. Mechanistically, PEP mitigated cardiac and renal damage by simultaneously regulating ACE-Ang II-AT1R and the ACE2-Ang (1-7)-MAS axis. Additionally, PEP increased the levels of short chain fatty acids by 224.16% and improved gut microbiota by increasing the abundance of Prevotella, Phascolarctobacterium, Clostridium_sensu_stricto and Bifidobacterium, at the same time as decreasing Bacteroides and Alistipes abundances. This study indicated that PEP prevented hypertension and associated heart and kidney damage by modulating the RAAS system and gut microbiota, which is valuable in guiding future development and optimal utilization of walnut meal. © 2024 Society of Chemical Industry.

In vitro protein digestive properties and peptidomic characterization of five whole component plant protein beverages using a pepsin-pancreatin model

Plant protein has received great attention for its potential nutrition and health benefits. In this study, the digestive properties and peptidomics of whole component plant protein beverages from soybean, chick pea, pea, oat, and quinoa were characterized using an in vitro pepsin-pancreatin digestion model. The study found that quinoa beverage had a higher in vitro protein digestibility (80.49 %), followed by pea, soybean, chick pea, and oat beverage (79.25–70.89 %). Additionally, quinoa and soybean beverage showed comparably higher in vitro digestible indispensable amino acid score (DIAAS) of 81–97, while chick pea and pea beverage had lower in vitro DIAAS of 58–79 due to low concentration of sulfur-containing AA (SAA). Meanwhile, peptides with molecular weight (MW) below 1 kDa occupied more than 93 % of the digested fraction in quinoa beverage, which might result in its higher DPPH scavenging activity, ABTS scavenging activity and ACE inhibitory activity with the IC50 value of 2.80, 0.20 and 0.90 mg/mL, respectively. Peptidomics characterization combined with rapid screening by PeptideRanker and BIOPEP database further suggested that cereals, especially oat and quinoa, released potentially bioactive peptides with a higher percentage (30.89 % and 22.81 %, respectively) compared to legumes like soybean and chick pea (13.30–18.52 %). Additionally, the identified active peptides were more likely to be derived from globular proteins. The methods and data here provided a reference for a better understanding of the digestive properties and nutritional recommendations of whole component plant protein product.

Compositional changes and physiological activities of fresh ginseng extracts prepared at various temperatures in subcritical water

BackgroundSubcritical water (SW) is regarded as an effective conversion technology for lignocellulosic biomass. The effect of SW on ginseng are limited to evaluate the ginsenoside composition of red ginseng, and there is little information on the effects of SW on fresh ginseng. MethodsThe general characteristics of ginseng extracts (GE) prepared with SW were evaluated in terms of brix, reducing sugar and residual solid content, and compositions of GE was estimated using chromatography. For utilization of GE as a bioactive food, the ginsenoside composition, antioxidative activity, angiotensin-converting enzyme (ACE) inhibitory activity, prebiotic potential and taste attributes were measured. ResultsIncreasing SW temperature decreased residual solid content of ginseng and the soluble compounds of GE were yielded by SW at 250 °C. Despite that ginsenoside content decreased with SW temperature, a steep increase in Rg5 was observed at 200 °C. The SW at 200–250 °C manifested the highest antioxidant activities and ACE inhibitory activity of GE. However, the GE prepared at greater than 250 °C completely lost prebiotic potentials. Based on electronic-tongue, umami taste was enhanced by SW at 200 °C, but sweetness and bitterness were dominated at 250–300 °C. ConclusionThe results demonstrated that SW has a potential application to convert lignocellulosic wastes generated from ginseng roots into bioactive food resource, and SW at ∼200 °C can be potentially used to enhance the physiological activities of GE.

Investigation of the regulatory effect of α-chymotrypsin-assisted hydrolysate from Sebastes schlegelii on blood pressure through in vitro, in silico ACE inhibitory activity, and in vivo spontaneously hypertensive rat hypertensive model

This study aimed to screen peptides with antihypertensive effects from the α-chymotrypsin hydrolysate of Sebastes schlegelii (SSA). SSA demonstrated ACE inhibitory activity with an IC50 value of 0.062 ± 0.001 mg/mL. The SSA significantly reduced body weight and systolic blood pressure in the SHR spontaneously hypertensive rat (SHR) model and improved hypertension-induced vasopathy and interstitial fibrosis in heart and vascular tissues, indicating the presence of ACE inhibitory peptides contributing to cardiovascular health. Peptide composition analysis identified fractions of SSA with potent ACE inhibitory activity, particularly those with molecular weights of 5 kDa or less. Further evaluation of ACE activity using Sephadex G-10 separated SSA fractions led to the amino acid sequence analysis of the most effective fraction (SSA-F1). Molecular docking simulations predicted that peptides from SSA-F1 inhibit ACE activity by binding to its active sites. This research suggests the potential of peptides from S. schlegelii for clinical hypertension treatment.

Peptidomics profiling and biological activities of grape pomace protein hydrolysates

Grape pomace protein isolate was hydrolysed by Alcalase, Flavourzyme and Protease either individually or in combination to produce hydrolysates with antihypertensive and antimicrobial properties. The degree of hydrolysis (DH) ranged between 22 and 52 % for Protease and Flavourzyme, respectively. Among all treatments, hydrolysates prepared using Flavourzyme exhibited the highest angiotensin-converting enzyme inhibitory (ACEi) activity, with an IC50 value of 91 μg/mL. The peptidomics analysis revealed that the peptides identified in Flavourzyme hydrolysate presented molecular features compatible with its bioactivity, like a high density of ACEi sequences per peptide. The hydrolysates were also able to inhibit the growth of Escherichia coli in a range between 9 and 54 % for Alcalase and Alcalase + Flavourzyme, respectively. Peptides in the most active hydrolysate evidenced a high occurrence of proline residues, which is a structural feature of some antimicrobial peptides.