Effects of natural peptides from food proteins on angiotensin converting enzyme activity and hypertension

Unraveling the kinase code: Role of protein kinase in lung cancer pathogenesis and therapeutic strategies

Lung cancer is a prominent cause of cancer-related deaths globally, prompting exploration into the molecular pathways governing cancer cell signaling. Recent insights highlight the critical role of kinases in carcinogenesis and metastasis, particularly in non-small cell lung cancer (NSCLC), where protein kinases significantly contribute to drug resistance. These diverse enzymes catalyze protein phosphorylation and are implicated in cancer through misregulated expression, amplification, aberrant phosphorylation, mutations, and chromosomal translocations. Amplifications of kinases serve as important diagnostic, prognostic, and predictive biomarkers across various cancers. Notably, the Phosphatidylinositol 3-kinase (PI3K)/AKT pathway is crucial for the survival and proliferation of tumor cells. Novel therapeutic approaches are being explored to precisely target these pathways. Peptide-based therapies offer specificity and reduced toxicity compared to conventional treatments, while gene therapy targets abnormal genetic expressions. Advances in nanotechnology and CRISPR/Cas9 systems enhance gene delivery methods, holding promise for targeting specific molecular pathways in lung cancer treatment and minimizing systemic toxicity.

Discovery of two novel ACE inhibitory peptides from soybeans: Stability, molecular interactions, and in vivo antihypertensive effects

Functional peptides that are derived from natural protein-rich foods possess a wide range of physiological and pharmacological properties and have become ideal alternatives to chemical drugs. In this study, two novel ACE inhibitory peptides, GKGLW (IC50 = 34.96 μM) and GDGLKW (IC50 = 33.98 μM), were screened and identified from soybeans through sequential stepwise double enzymolysis, and their molecular mechanisms were explored by combining computational simulation. Initially, the optimal combination of alkaline protease and chymotrypsin was determined through the analysis of the enzymatic preferences of five different proteases and the ACE inhibitory activity of their hydrolyzed products. Following purification by ultrafiltration and Sephadex G-25 gel chromatography, the amino acid sequences of the peptides were identified by LC-MS/MS and selectively synthesized based on binding energy. Molecular docking and dynamics simulation/generalized born surface area calculation indicated that the peptides mainly interacted with key residues Ala354, Tyr523, and His353 in the ACE active pocket through hydrogen bonds, and hydrophobic and aromatic amino acids were beneficial to the ACE inhibitory activity of the peptides. Additionally, the two peptides showed good stability in simulating the gastrointestinal digestion process. The antihypertensive effects of these two peptides were further verified in a spontaneously hypertensive rats (SHRs) model. In conclusion, this study successfully identified two ACE inhibitory peptides, GKGLW and GDGLKW, from soybeans by combining proteases with different characteristics for stepwise degradation of soy protein, revealing their potential application value as antihypertensive functional foods.

Antihypertensive effects of rice peptides involve intestinal microbiome alterations and intestinal inflammation alleviation in spontaneously hypertensive rats

Gut dysbiosis serves as an underlying risk factor for the development of hypertension. The resolution of this dysbiosis has emerged as a promising strategy in improving hypertension. Food-derived bioactive protein peptides have become increasingly more attractive in ameliorating hypertension, primarily due to their anti-inflammatory and anti-oxidant activities. However, the regulatory mechanisms linking rice peptides (RP), gut dysbiosis, and hypertension remain to be fully elucidated. In our study, male spontaneously hypertensive rats (SHR) were fed with chow diet and concomitantly treated with ddH2O (Ctrl) or varying doses of rice peptides (20, 100, or 500 mg (kg bw day)-1 designated as low-dose RP, LRP; medium-dose RP, MRP; high-dose RP, HAP) or captopril (Cap) by intragastric administration. Wistar-Kyoto (WKY) rats served as the normotensive control group and were orally administered with ddH2O. We observed beneficial effects of RP in lowering blood pressure and ameliorating cardiovascular risk profiles, as evidenced by improvements in glucolipid metabolic disorders, hepatic and renal damage, left ventricular hypertrophy and endothelial dysfunction in hypertensive rats. More importantly, we found that RP attenuated intestinal pathological damage, improved impaired intestinal barrier, and reduced intestinal inflammation by inhibiting the HMGB1-TLR4-NF-κB pathway. Notably, multi-omics integrative analyses have revealed that RP altered the composition and function of the gut microbiota. This is exemplified by the observed enrichment of beneficial bacterial constituents, such as g_Lactobacillus, g_Lactococcus, s_Lactobacillus_intestinalis, and Lactococcus lactis, and elevated production of microbiota-derived short-chain fatty acid metabolites. Collectively, these studies suggest that the hypotensive effects of RP may be associated with modulation of the gut microbiota and its short-chain fatty acids metabolites. This implicates the microbiota-gut-HMGB1-TLR4-NF-κB axis as a novel venue for the amelioration of hypertension and its complications.

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

BACKGROUND

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.

RESULTS

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.

CONCLUSION

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.

Sequence-Activity Relationship of Angiotensin-Converting Enzyme Inhibitory Peptides Derived from Food Proteins, Based on a New Deep Learning Model

Food-derived peptides are usually safe natural drug candidates that can potentially inhibit the angiotensin-converting enzyme (ACE). The wet experiments used to identify ACE inhibitory peptides (ACEiPs) are time-consuming and costly, making it important and urgent to reduce the scope of experimental validation through bioinformatics methods. Here, we construct an ACE inhibitory peptide predictor (ACEiPP) using optimized amino acid descriptors (AADs) and long- and short-term memory neural networks. Our results show that combined-AAD models exhibit more efficient feature transformation ability than single-AAD models, especially the training model with the optimal descriptors as the feature inputs, which exhibits the highest predictive ability in the independent test (Acc = 0.9479 and AUC = 0.9876), with a significant performance improvement compared to the existing three predictors. The model can effectively characterize the structure-activity relationship of ACEiPs. By combining the model with database mining, we used ACEiPP to screen four ACEiPs with multiple reported functions. We also used ACEiPP to predict peptides from 21,249 food-derived proteins in the Database of Food-derived Bioactive Peptides (DFBP) and construct a library of potential ACEiPs to facilitate the discovery of new anti-ACE peptides.

Branched-chain amino acids and the risk of hypertension; a persian cohort-based study

BACKGROUND

The association of hypertension (HTN) and different types of dietary amino acids is not yet clear. The aim of the present study was to investigate the association of branch chain amino acids (BCAAs) and the prevention of HTN.

METHODS

This cross-sectional study was conducted on 4184 people aged 35 to 70 using data from the Sabzevar Persian cohort study in Sabzevar, Iran. Data on dietary intake of BCAAs including leucine, isoleucine, and valine were obtained using a validated Food Frequency Questionnaire (FFQ). Multivariable logistic regression analysis assessed the link between HTN and BCAAs.

RESULTS

The results showed that participants with HTN had a higher total protein and BCAAs intake than participants with normal BP (P < 0.01). A marginally significant association was found between the risk of HTN with the total intake of BCAAs (OR = 1.018, CI95%: 1.001-1.035, P = 0.04), leucine (OR = 1.040, CI95%:1.002-1.080, P = 0.03), isoleucine (OR = 1.068, CI95%:1.001-1.140, P = 0.04), and valine (OR = 1.060, CI95%:1.003-1.121, P = 0.04). However, the association disappeared after adjusting the total protein and calorie intake.

CONCLUSIONS

The results indicated that the dietary intake of BCAAs may be associated with the risk of HTN. Future longitudinal research is warranted.

In vitro strategies to understand the impact of oral intake on the bioavailability and bioactivity of peptides from brewing by-products

Bioactive peptides from brewer's spent grain (BSG) and brewer's spent yeast (BSY), two by-products of the brewing industry, have great potential as functional food ingredients, dietary supplements or nutraceuticals to reduce the risk of numerous pathological conditions. Nevertheless, the oral administration of these peptides poses great challenges since peptides must undergo gastrointestinal digestion, intestinal absorption and hepatic metabolism, which can affect their bioavailability and, therefore, the expected outcomes. This review provides a comprehensive and critical analysis of the potential impact of the oral route on the bioactivity of BSG/BSY peptides as assessed by in vitro assays and identifies research gaps that require novel approaches/methodologies. The data collected indicate that in addition to the significant influence of gastrointestinal digestion, intestinal absorption and hepatic metabolism also have a major impact on the bioactivity of brewing peptides. The major gap identified was the insufficient evidence regarding hepatic metabolism, which points for the need of employing in vitro assays in this research field to provide such clarification. Thus, to reach the market, the impact of the oral route on the bioactivities of BSG/BSY peptides must be properly studied in vitro to allow adequate/effective administration (dosage/frequency) with a beneficial impact on the population health.

Duality of Branched-Chain Amino Acids in Chronic Cardiovascular Disease: Potential Biomarkers versus Active Pathophysiological Promoters

Branched-chain amino acids (BCAAs), comprising leucine (Leu), isoleucine (Ile), and valine (Val), are essential nutrients vital for protein synthesis and metabolic regulation via specialized signaling networks. Their association with cardiovascular diseases (CVDs) has become a focal point of scientific debate, with emerging evidence suggesting both beneficial and detrimental roles. This review aims to dissect the multifaceted relationship between BCAAs and cardiovascular health, exploring the molecular mechanisms and clinical implications. Elevated BCAA levels have also been linked to insulin resistance (IR), type 2 diabetes mellitus (T2DM), inflammation, and dyslipidemia, which are well-established risk factors for CVD. Central to these processes are key pathways such as mammalian target of rapamycin (mTOR) signaling, nuclear factor kappa-light-chain-enhancer of activate B cells (NF-κB)-mediated inflammation, and oxidative stress. Additionally, the interplay between BCAA metabolism and gut microbiota, particularly the production of metabolites like trimethylamine-N-oxide (TMAO), adds another layer of complexity. Contrarily, some studies propose that BCAAs may have cardioprotective effects under certain conditions, contributing to muscle maintenance and metabolic health. This review critically evaluates the evidence, addressing the biological basis and signal transduction mechanism, and also discusses the potential for BCAAs to act as biomarkers versus active mediators of cardiovascular pathology. By presenting a balanced analysis, this review seeks to clarify the contentious roles of BCAAs in CVD, providing a foundation for future research and therapeutic strategies required because of the rising prevalence, incidence, and total burden of CVDs.

Dietary branched-chain amino acids intake and new-onset hypertension: a nationwide prospective cohort study in China

OBJECTIVE

This study aimed to investigate the relationship between dietary branched-chain amino acids (BCAAs) and the risk of developing hypertension.

METHODS

A cohort study of 14,883 Chinese adults without hypertension at baseline with were followed for an average of 8.9 years. Dietary intakes of BCAAs, including Ile, Leu, and Val, were collected using 3-day 24-h meal recall and household condiment weighing. Cox proportional hazards regression, restricted cubic splines, interaction analysis, and sensitivity analysis were used to assess the relationship between dietary BCAAs and risk of developing self-reported hypertension, adjusting for age, gender, region, body mass index (BMI), smoking and drinking status, physical activity, energy intake, salt intake.

RESULTS

Among 14,883 study subjects, 6386(42.9%) subjects aged ≥ 45 years at baseline, 2692 (18.1%) had new-onset hypertension during the study period, with a median age of 56 years. High levels of dietary BCAAs were associated with an increased risk of new-onset hypertension. Compared with the 41st-60th percentile, multivariable adjusted hazard ratio (HR) for new-onset hypertension was 1.16 (95% CI 1.01-1.32) for dietary BCAAs 61st-80th percentiles, 1.30 (1.13-1.50) for 81st-95th, 1.60 (1.32-1.95) for 96th-100th. The cut-off value of new-onset hypertension risk, total BCAAs, Ile, Leu, and Val were 15.7 g/day, 4.1 g/day, 6.9 g/day, 4.6 g/day, respectively, and the proportion of the population above these intake values were 13.9%, 13.1%, 15.4%, and 14.4%, respectively. Age, BMI, and salt intake had an interactive effect on this relationship (P < 0.001).

CONCLUSION

There was a significant positive association between total dietary BCAAs, Ile, Leu, Val intake and the risk of developing hypertension, after adjustment for confounders. This relationship was influenced by age, BMI, and salt intake. Further research is needed to clarify the mechanism and potential role of BCAAs in the pathogenesis of hypertension.

Identification and Screening of Potential ACE2 Activating Peptides from Soybean Protein Isolate Hydrolysate against Ang II-Induced Endothelial Dysfunction

Angiotensin-converting enzyme 2 (ACE2) is a counterregulator against ACE by converting angiotensin II (Ang II) to Ang-(1-7), and its down-regulation leads to endothelial dysfunction in the vascular system. In the present study, we investigated the effects of soybean protein isolate hydrolysate (SPIH) on Ang II-induced endothelial dysfunction with its underlying mechanisms via ACE2 activation in human umbilical vein endothelial cells (HUVECs). We further screened potential ACE2 activating peptides by peptidomics analysis combined with bioinformatics tools. Results showed that SPIH remarkably attenuated Ang II-induced cell migration from 129 to 92%, decreased the ROS level from 2.22-fold to 1.45-fold, and increased NO concentration from 31.4 ± 0.7 to 43.7 ± 0.1 μM in HUVECs. However, these beneficial effects were reversed by ACE2 inhibitor MLN-4760 to a certain extent, indicating the modulation of ACE2. Further results revealed that SPIH (1 mg/mL) significantly increased the expression and activity of ACE2 and two novel ACE2 activating peptides with different mechanisms were explored from SPIH. IVPQ and IAVPT (50 μM) enhanced ACE2 activity, and only IVPQ (50 μM) increased ACE2 protein expression in HUVECs. These findings furthered our understanding of the antihypertensive mechanism of SPIH mediating the ACE2 activation on vascular endothelium.

The biological role of prolyl oligopeptidase and the procognitive potential of its peptidic inhibitors from food proteins

Prolyl oligopeptidase (POP) is a conserved serine protease belonging to proline-specific peptidases. It has both enzymatic and non-enzymatic activity and is involved in numerous biological processes in the human body, playing a role in e.g., cellular growth and differentiation, inflammation, as well as the development of some neurodegenerative and neuropsychiatric disorders. This article describes the physiological and pathological aspects of POP activity and the state-of-art of its peptidic inhibitors originating from food proteins, with a particular focus on their potential as cognition-enhancing agents. Although some milk, meat, fish, and plant protein-derived peptides have the potential to be applied as natural, procognitive nutraceuticals, their effectiveness requires further evaluation, especially in clinical trials. We demonstrated that the important features of the most promising POP-inhibiting peptides are very short sequence, high content of hydrophobic amino acids, and usually the presence of proline residue.

Innovation in sweet rice wine with high antioxidant activity: Eucommia ulmoides leaf sweet rice wine

The dried leaves of Eucommia ulmoides Oliv., which have a high nutritional value, are mainly used in both medicine and food. In this study, we used Eucommia ulmoides leaf superfine powder as an additive in the fermentation of glutinous rice (Semen Oryzae Glutinosae) to develop a new healthcare product, Eucommia leaf sweet rice wine. The fermentation conditions were optimized, and the nutrient value was evaluated through analyses of metabolites, functional compositions, antioxidant capacity, and antihyperglycemic, antihyperlipidemic, and antihypertensive abilities. The metabolic analysis demonstrated that Eucommia leaf sweet rice wine contained a large number of flavonoids and other metabolites. Eucommia leaf sweet rice wine had higher contents of flavonoid (729.0 ± 0.11 μg/g), free amino acids (55.0 ± 0.37 μg/g), polyphenol (150.0 ± 0.43 μg/g), and polysaccharide (0.25 ± 0.03 μg/g) than traditional sweet rice wine, with increases of 14.7, 2.6, 6.8, and 6.3 times, respectively. In addition, an analysis of antioxidant capacity in vitro revealed that Eucommia leaf sweet rice wine had a high level of activity in scavenging 2, 2-diphenyl-1-picrylhydrazyl (DPPH), superoxide anion, and hydroxyl radicals, as well as in reducing iron, indicating that it was a strong antioxidant. Furthermore, Eucommia leaf sweet rice wine had a high cholate binding capacity and could significantly inhibit α-amylase, α-glucosidase, and angiotensin-converting enzyme (ACE) activity. In conclusion, this study developed a new application of Eucommia leaf in sweet rice wine fermentation and brewed Eucommia leaf sweet rice wine with strong antioxidant activity and positive antihypertensive, antihyperglycemic, and antihyperlipidemic effects in vitro. This study suggests new opportunities for the wider use of Eucommia ulmoides leaves and adds variety to sweet rice wine.

In Vitro and In Vivo Antihypertensive Effect of Milk Fermented with Different Strains of Common Starter Lactic Acid Bacteria

Currently, functional dairy products pave a promising way for the prophylaxis of essential hypertension, and the search for new strains capable of producing such products is a constant challenge for scientists around the world. In this study, the antihypertensive properties of milk fermented with several strains of traditional yogurt starters (Lactobacillus delbrueckii strains Lb100 and Lb200; Lactococcus lactis strains dlA, AM1 and MA1; Streptococcus thermophilus strains 159 and 16t) and one strain of non-conventional probiotic starter (Lacticaseibacillus paracasei ABK) were assessed. The in vitro assessment using angiotensin-converting enzyme inhibition assay was performed for all fermentation products, and the best performed products were tested in vivo using Spontaneously Hypertensive Rat (SHR) animal model. In addition, for the best performed products the fatty acid (FA) composition and FA-related nutritional indices were determined. As a result, the milk fermented with two strains (Lb. delbrueckii LB100 and Lc. lactis AM1) demonstrated significant antihypertensive effect during both in vitro and in vivo experiments. Moreover, the milk fermented with Lb. delbrueckii Lb100 demonstrated significantly better FA-related nutritional indexes and lowered total cholesterol in SHRs upon regular consumption. The obtained results can be used in the future to develop new starter cultures producing effective functional antihypertensive dairy products.

Unconventional microbial proteases as promising tools for the production of bioactive protein hydrolysates

Enzymatic hydrolysis is the most prominent strategy to release bioactive peptides from different food proteins and protein-rich by-products. Unconventional microbial proteases (UMPs) have gaining increased attention for such purposes, particularly from the 2010s. In this review, we present and discuss aspects related to UMPs production, and their use to obtain bioactive protein hydrolysates. Antioxidant and anti-hypertensive potentials, commonly evaluated through in vitro testing, are mainly reported. The in vivo bioactivities of protein hydrolysates and peptides produced through UMPs action are highlighted. In addition to bioactivities, enzymatic hydrolysis acts by modulating the functional properties of proteins for potential food uses. The compiled literature indicates that UMPs are promising biocatalysts to generate bioactive protein hydrolysates, adding up to commercially available enzymes. From the recent interest on this topic, continuous and in-depth research is needed to advance toward the applicability and commercial utility of both UMPs and obtained hydrolysates.

Small molecule angiotensin converting enzyme inhibitors: A medicinal chemistry perspective

Angiotensin-converting enzyme (ACE), a zinc metalloprotein, is a central component of the renin-angiotensin system (RAS). It degrades bradykinin and other vasoactive peptides. Angiotensin-converting-enzyme inhibitors (ACE inhibitors, ACEIs) decrease the formation of angiotensin II and increase the level of bradykinin, thus relaxing blood vessels as well as reducing blood volume, lowering blood pressure and reducing oxygen consumption by the heart, which can be used to prevent and treat cardiovascular diseases and kidney diseases. Nevertheless, ACEIs are associated with a range of adverse effects such as renal insufficiency, which limits their use. In recent years, researchers have attempted to reduce the adverse effects of ACEIs by improving the selectivity of ACEIs for structural domains based on conformational relationships, and have developed a series of novel ACEIs. In this review, we have summarized the research advances of ACE inhibitors, focusing on the development sources, design strategies and analysis of structure-activity relationships and the biological activities of ACE inhibitors.

Diacerein alleviates Ang II-induced cardiac inflammation and remodeling by inhibiting the MAPKs/c-Myc pathway

BACKGROUND

Heart failure is a common event in the course of hypertension. Recent studies have highlighted the key role of the non-hemodynamic activity of angiotensin II (Ang II) in hypertension-related cardiac inflammation and remodeling. A naturally occurring compound, diacerein, exhibits anti-inflammatory activities in various systems.

HYPOTHESIS/PURPOSE

In this study, we have examined the potential effects of diacerein on Ang II-induced heart failure.

METHODS

C57BL/6 mice were administered Ang II by micro-osmotic pump infusion for 4 weeks to develop hypertensive heart failure. Mice were treated with diacerein by gavage for final 2 weeks. RNA-sequencing analysis was performed to explore the potential mechanism of diacerein.

RESULTS

We found that diacerein could inhibit inflammation, myocardial fibrosis, and hypertrophy to prevent heart dysfunction, without the alteration of blood pressure. To explore the potential mechanism of diacerein, RNA-sequencing analysis was performed, indicating that MAPKs/c-Myc pathway is involved in that cardioprotective effects of Diacerein. We further confirmed that diacerein inhibits Ang II-activated MAPKs/c-Myc pathway to reduce inflammatory response in mouse hearts and cultured cardiomyocytes. Deficiency of MAPKs or c-Myc in cardiomyocytes abolished the anti-inflammatory effects of diacerein.

CONCLUSION

Our results indicate that diacerein protects hearts in Ang II-induced mice through inhibiting MAPKs/c-Myc-mediated inflammatory responses, rendering diacerein a potential therapeutic candidate agent for hypertensive heart failure.

Protein Hydrolysates from Brewing By-Products as Natural Alternatives to ACE-Inhibitory Drugs for Hypertension Management

Simple Summary

Hypertension is the predominant risk factor for cardiovascular disease, which is the leading cause of mortality and morbidity worldwide. The search for natural compounds with antihypertensive properties, such as bioactive peptides from brewing by-products (spent grain and yeast), which are less likely to cause severe side effects compared with anti-hypertensive drugs, is of major importance to reduce cardiovascular events. Since oral intake of these peptides may modify their expected effects, the aim of the present study was to simulate oral administration and evaluate the impact of gastrointestinal digestion, intestinal absorption, and liver metabolism on the effectiveness of those bioactive peptides and determine their potential to be used as supplements or nutraceuticals as well as anti-hypertensive drugs before moving forward to animal studies. Results showed that peptides derived from the brewing industry maintain or present higher antihypertensive activity after simulation of oral administration, validating the usefulness of these peptides to reduce the risk, ameliorate, or treat primary hypertension. In conclusion, this study reinforces, through in vitro studies, the benefits of oral administrated brewing bioactive peptides to directly manage hypertension by lowering blood pressure, thus being promising compounds.

Abstract

The treatment of hypertension is of major importance to reduce the risk of cardiovascular disease, the leading cause of death worldwide. Angiotensin-converting enzyme (ACE) inhibitors are anti-hypertensive drugs associated with several side effects. Natural products, namely bioactive peptides from brewing by-products, brewers’ spent grain (BSG), and yeast (BSY), are promising alternatives since they can inhibit ACE in vitro. However, the oral intake of these peptides may modify their expected inhibitory effect owing to possible changes in active peptides’ bioavailability, which have not been assessed so far. The goal of this study was to simulate oral administration to evaluate BSG/BSY peptides’ effectiveness by submitting protein hydrolysates sequentially to simulated gastrointestinal digestion, intestinal absorption (Caco-2 cells), and liver metabolism (HepG2 cells). MTT assay was used to assess BSG/BSY protein hydrolysates safeness. The ACE-inhibitory potential of initial and final protein hydrolysates (BSY, BSG, and a new product, MIX) were tested using a fluorometric assay and compared with captopril (1 µM, an ACE-inhibitory drug). Simulation of oral administration greatly increased BSY and MIX protein hydrolysates’ ACE-inhibitory capacity, though final MIX and BSG revealed greater ACE-inhibitory potential than captopril. Notwithstanding, all final protein hydrolysates presented ACE-inhibitory capacity, thus being promising compounds to manage hypertension.

The Effect of Soybean Peptides on Improving Quality and the ACE Inhibitory Bioactivity of Extruded Rice

It is crucial to address the dietary problems of hypertensive patients. The effect and mechanism of different contents of soybean protein on cooking quality and angiotensin-converting enzyme (ACE) inhibitory action in the extruded rice were firstly investigated. The results showed that the extruded rice with soybean protein possessed the higher taste value (90.32 ± 2.31), hardness (2.65 ± 0.01 g), and good pasting quality (p ≤ 0.05). Meanwhile, the soybean protein notably retarded the starch digestibility; the sample with 6% soybean protein showed the fewest rapidly digestible starch (RDS) content (78.82 ± 0.01 mg g−1) and the most slowly digestible starch (SDS) content (8.97 ± 0.45 mg g−1). Importantly, the ACE inhibition rate improved from 17.09 ± 0.01% to 74.02 ± 0.65% in the 6% soybean protein sample because of the production of peptides. The peptide composition of samples were compared, which showed that the effective ACE-inhibitory peptides usually contain 2~20 amino acids, and Pro, Leu, Ile, Val, Phe, and Ala were the main components. Overall, moderate soybean protein would give a good quality and lower ACE activity in extruded food.

Mechanistic Insights into Angiotensin I-Converting Enzyme Inhibitory Tripeptides to Decipher the Chemical Basis of Their Activity

Food proteins are an important source of bioactive peptides, and the angiotensin I-converting enzyme (ACE) inhibitors are worthy of attention for their possible beneficial effects in subjects with mild hypertension. However, the chemical basis underpinning their activity is not well-understood, hampering the discovery of novel inhibitory sequences from the plethora of peptides encrypted in food proteins. This work combined computational and in vitro investigations to describe precisely the chemical basis of potent inhibitory tripeptides. A substantial set of previously uncharacterized tripeptides have been investigated in silico and in vitro, and LCP was described for the first time as a potent ACE inhibitory peptide with IC₅₀ values of 8.25 and 6.95 μM in cell-free and cell-based assays, respectively. The outcomes presented could serve to better understand the chemical basis of already characterized potent inhibitory tripeptides or as a blueprint to design novel and potent inhibitory peptides and peptide-like molecules.

Underlying antihypertensive mechanism of egg white-derived peptide QIGLF using renal metabolomics analysis

The kidney is an important target organ in the treatment of hypertension, but the effect of peptide QIGLF with antihypertensive activity on kidneys remains unknown. In the work, we aimed to further understand the hypotensive effects of QIGLF in spontaneously hypertensive rats (SHRs) using widely targeted metabolomics technology to investigate the kidney metabolic profiling variations. After four weeks of oral administration, the results showed different renal metabolomics profiles between QIGLF and model groups. Besides, a total of 10 potential biomarkers were identified, that is, 3-hydroxybutanoate, 20-hydroxyeicosatetraenoic acid, 19(S)-hydroxyeicosatetraenoic acid, 15-oxoETE, L-ornithine, malonate, uridine, uridine 5'-monophosphate, argininosuccinic acid, and N-carbamoyl-L-aspartate. These metabolites might exhibit antihypertensive activity of QIGLF by regulating synthesis and degradation of ketone bodies, arachidonic acid metabolism, pyrimidine metabolism, and arginine biosynthesis. These findings suggest that QIGLF might alleviate hypertension by inhibiting renal inflammation, promoting natriuresis, and regulating renal nitric oxide production.

IRW (Isoleucine-Arginine-Tryptophan) Improves Glucose Tolerance in High Fat Diet Fed C57BL/6 Mice via Activation of Insulin Signaling and AMPK Pathways in Skeletal Muscle

IRW (Isoleucine−Arginine−Tryptophan), has antihypertensive and anti-inflammatory properties in cells and animal models and prevents angiotensin-II- and tumor necrosis factor (TNF)-α-induced insulin resistance (IR) in vitro. We investigated the effects of IRW on body composition, glucose homeostasis and insulin sensitivity in a high-fat diet (HFD) induced insulin resistant (IR) model. C57BL/6 mice were fed HFD for 6 weeks, after which IRW was incorporated into the diet (45 or 15 mg/kg body weight (BW)) until week 14. IRW45 (at a dose of 45 mg/kg BW) reduced BW (p = 0.0327), fat mass gain (p = 0.0085), and preserved lean mass of HFD mice (p = 0.0065), concomitant with enhanced glucose tolerance and reduced fasting glucose (p < 0.001). In skeletal muscle, IRW45 increased insulin-stimulated protein kinase B (AKT) phosphorylation (p = 0.0132) and glucose transporter 4 (GLUT4) translocation (p < 0.001). Angiotensin 2 receptor (AT2R) (p = 0.0024), phosphorylated 5′-AMP-activated protein kinase (AMPKα) (p < 0.0124) and peroxisome proliferator-activated receptor gamma (PPARγ) (p < 0.001) were enhanced in skeletal muscle of IRW45-treated mice, as was the expression of genes involved in myogenesis. Plasma angiotensin converting enzyme-2 (ACE2) activity was increased (p = 0.0016). Uncoupling protein-1 in white adipose tissue (WAT) was partially restored after IRW supplementation. IRW improves glucose tolerance and body composition in HFD-fed mice and promotes glucose uptake in skeletal muscle via multiple signaling pathways, independent of angiotensin converting enzyme (ACE) inhibition.

Inverse Association Between Variety of Proteins With Appropriate Quantity From Different Food Sources and New-Onset Hypertension

The relationships of the variety and quantity of different sources of dietary proteins with hypertension remain uncertain. We aimed to investigate associations between the variety and quantity of proteins intake from 8 major food sources and new-onset hypertension among 12 177 participants from the China Health and Nutrition Survey. Dietary intake was measured by 3 consecutive 24-hour dietary recalls combined with a household food inventory. The variety score of protein sources was defined as the number of protein sources consumed at the appropriate level, accounting for types and quantity of proteins. New-onset hypertension was defined as systolic blood pressure ≥140 mm Hg and diastolic blood pressure ≥90 mm Hg, or physician-diagnosed hypertension or receiving antihypertensive treatment, during the follow-up. During a median follow-up of 6.1 years, there were U-shaped associations of percentages energy from total, unprocessed or processed red meat-derived, whole grain-derived, and poultry-derived proteins with new-onset hypertension; an reverse J-shaped association of fish-derived protein with new-onset hypertension; L-shaped associations of eggs-derived and legumes-derived proteins with new-onset hypertension; and an reverse L-shaped association of refined grain-derived protein with new-onset hypertension (all P values for nonlinearity <0.001). That is, for each protein, there is a window of consumption (appropriate level) where the risk of hypertension is lower. Moreover, a significantly lower risk of new-onset hypertension was found in those with higher variety score of protein sources (per score increment, hazard ratio, 0.74 [95% CI, 0.72-0.76]). In summary, there was an inverse association between the variety of proteins with appropriate quantity from different food sources and new-onset hypertension.

UV-Crosslinked Electrospun Zein/PEO Fibroporous Membranes for Wound Dressing

Electrospun zein membranes are suitable for various biomedical applications. A UV-crosslinked electrospun membrane of a zein/PEO blend for wound healing application was explored in this work. The improvement in mechanical properties of the membrane after UV crosslinking was attributed to the change in protein conformation from an α-helix to a β-sheet. The circular dichroism (CD) spectra and FTIR spectra confirmed this conformational change. XRD analysis was shown to prove the amorphous nature of polymer blends with specific broad peaks at 2θ = 9° and 20°. The water vapor transmission rate (WVTR) of the membrane was found to be in the range of 1500-2000 g m^-2 day^-1, which was well suited with that of commercially available wound dressing material. Enough number of available functional groups like thiol, amino, and hydroxyl groups supplement a blood clotting index (BCI) to the matrix, causing 99% BCI within 4 min. A 91% cell viability result in the MTT assay with human dermal fibroblast cells confirmed the noncytotoxicity of the membrane. Tripeptides produced after the thermolysin-based hydrolysis of zein caused inhibition of TGF β1 expression and thus increased fibroblast and collagen production. The membrane stimulated 54% more collagen production compared to control cells at day 2 and caused 84% wound closure in human dermal fibroblast cells, which were desirable index markers of a potential wound care material.

Angiotensin-Converting Enzyme (ACE) Inhibitory Activity and Mechanism Analysis of N-(1-Deoxy-d-fructos-1-yl)-histidine (Fru-His), a Food-Derived Amadori Compound

N-(1-Deoxy-d-fructos-1-yl)-histidine (Fru-His), one of the Amadori compounds, widely presents in processed foods, and its potential functional activities have attracted extensive attention in recent years. In this work, the angiotensin-converting enzyme (ACE) inhibitory activity and mechanism of Fru-His were investigated. The IC₅₀ value of Fru-His was 0.150 ± 0.019 mM, and there was no obvious degradation of Fru-His after digestion simulation, showing that Fru-His has good ACE inhibition and digestive stability. Fru-His was a competitive inhibitor according to the enzyme inhibition kinetic analysis. The interaction between ACE and Fru-His occurred spontaneously mainly through hydrogen bonding, and the process was accompanied by fluorescence quenching and the alteration of the secondary structure of ACE. The molecular docking data supported the above results. Fru-His was attached to ACE's S1 active pocket through hydrogen bonds and interacted with zinc ions in active sites. The present study demonstrates that food-derived Fru-His has the potential to relieve hypertension.

Prediction of Bioactive Peptides From Chicken Feather and Pig Hair Keratins Using In Silico Analysis Based on Fragmentomic Approach

BACKGROUND

Keratin is among the most abundant structural proteins of animal origin, however it remains broadly underutilized. <P> Objective: Bioinformatic investigation was performed to evaluate selected keratins originating from mass-produced waste products, i.e., chicken feathers and pig hair, as potential sources of bioactive peptides. <P> Methods: Pepsin, trypsin, chymotrypsin, papain, and subtilisin were used for in silico keratinolysis with the use of "Enzyme(s) action" and fragmentomic analysis of theoretical products was performed using "Profiles of potential biological activity" in BIOPEP-UWM database of bioactive peptides. Bioactivity probability calculation and toxicity prediction of the peptides obtained were estimated using PeptideRanker and ToxinPred tools, respectively. <P> Results: Our results showed that the keratins are a potential source of a variety of biopeptides, including dipeptidyl peptidase IV, angiotensin converting enzyme, prolyl endopeptidase inhibitory and antioxidative. Papain and subtilisin were found to be the most appropriate enzymes for keratin hydrolysis. This study presents possible structures of keratin-derived bioactive peptides that have not been previously described. <P> Conclusion: Our data suggest additional in vitro and in vivo studies to verify theoretical predictions and further investigate the possibility of using keratin-rich waste as a source of peptide nutraceuticals.

Relations of Variety and Quantity of Dietary Proteins Intake from Different Sources with Mortality Risk: A Nationwide Population-Based Cohort

OBJECTIVES

The relations of variety and quantity of dietary proteins intake from different sources with mortality risk were still controversial. We aimed to examine the associations of variety and quantity of different sourced proteins with all-cause mortality risk in adults and older adults.

MATERIALS AND METHODS

17,310 participants (mean age was 44.0 [SD: 15.9] years and 51.0% were females) with utilizable data from the China Health and Nutrition Survey were included. Dietary intake was collected using three consecutive 24-h dietary recalls combined with a household food inventory. The variety score of protein sources was defined as the number of proteins consumed at the appropriate level, accounting for both types and quantity of proteins. The primary outcome was all-cause mortality.

RESULTS

Over a median follow-up of 9.0 years, 1324 (7.6%) death cases were reported. There were reversed J-shaped relationships of percentages energy from total protein, and protein from legume with all-cause mortality; U-shaped relationships of proteins from unprocessed red meat, processed red meat, poultry and whole grain with all-cause mortality; L-shaped relationships of proteins from egg and fish with all-cause mortality; and a reversed L-shaped relationship of protein from refined grain with all-cause mortality (all P values for nonlinearity < 0.001). Moreover, there was a significant inverse association between the variety score of protein sources with overall mortality risk (per score increment, HR, 0.69; 95%CI, 0.66-0.72).

CONCLUSIONS

Greater variety of proteins with appropriate quantity from different food sources was associated with significantly lower risk of mortality in Chinese adults and older adults.

Angiotensin I-converting enzyme inhibitory peptide: an emerging candidate for vascular dysfunction therapy

Abnormal vasoconstriction, inflammation, and vascular remodeling can be promoted by angiotensin II (Ang II) in the renin-angiotensin system (RAS), leading to vascular dysfunction diseases such as hypertension and atherosclerosis. Researchers have recently focused on angiotensin I-converting enzyme inhibitory peptides (ACEIPs), that have desirable efficacy in vascular dysfunction therapy due to Ang II reduction by inhibiting ACE activity. Promising methods for the large-scale preparation of ACEIPs include selective enzymatic hydrolysis and microbial fermentation. Thus far, ACEIPs have been widely reported to be hydrolyzed from protein-rich sources, including animals, plants, and marine organisms, while many emerging microorganism-derived ACEIPs are theoretically biosynthesized through the nonribosomal peptide synthase (NRPS) pathway. Notably, vasodilatation, anti-inflammation, and vascular reconstruction reversal of ACEIPs are strongly correlated. However, the related molecular mechanisms underlying signal transduction regulation in vivo remain unclear. We provide a comprehensive update of the ACE-Ang II-G protein-coupled type 1 angiotensin receptor (AT1R) axis signaling and its functional significance for potential translation into therapeutic strategies, particularly targeting AT1R by ACEIPs, as well as specific related signaling pathways. Future studies are expected to verify the biosynthetic regulatory mechanism of ACEIPs via the NRPS pathway, the effect of gut microbiota metabolism on vascular dysfunction and rigorous studies of ACE-Ang II-AT1R signaling pathways mediated by ACEIPs in large animals and humans.

A novel angiotensin I-converting enzyme inhibitory peptide derived from the trypsin hydrolysates of salmon bone proteins

When fish are processed, fish bone becomes a key component of the waste, but to date very few researchers have sought to use fish bone to prepare protein hydrolysates as a means of adding value to the final product. This study, therefore, examines the potential of salmon bone, through an analysis of the benefits of its constituent components, namely fat, moisture, protein, and ash. In particular, the study seeks to optimize the process of enzymatic hydrolysis of salmon bone with trypsin in order to produce angiotensin-I converting enzyme (ACE) inhibitory peptides making use of response surface methodology in combination with central composite design (CCD). Optimum hydrolysis conditions concerning DH (degree of hydrolysis) and ACE-inhibitory activity were initially determined using the response surface model. Having thus determined which of the salmon bone protein hydrolysates (SBPH) offered the greatest level of ACE-inhibitory activity, these SBPH were duly selected to undergo ultrafiltration for further fractionation. It was found that the greatest ACE-inhibitory activity was achieved by the SBPH fraction which had a molecular weight lower than 0.65 kDa. This fraction underwent further purification using RP-HPLC, revealing that the F7 fraction offered the best ACE-inhibitory activity. For ACE inhibition, the ideal peptide in the context of the F7 fraction comprised eight amino acids: Phe-Cys-Leu-Tyr-Glu-Leu-Ala-Arg (FCLYELAR), while analysis of the Lineweaver-Burk plot revealed that the FCLYELAR peptide can serve as an uncompetitive ACE inhibitor. An examination of the molecular docking process showed that the FCLYELAR peptide was primarily able to provide ACE-inhibitory qualities as a consequence of the hydrogen bond interactions taking place between ACE and the peptide. Furthermore, upon isolation form the SBPH, the ACE-inhibitory peptide demonstrated ACE-inhibitory capabilities in vitro, underlining its potential for applications in the food and pharmaceutical sectors.

Inhibitory mechanism of angiotensin-converting enzyme inhibitory peptides from black tea

The aim of this work is to discover the inhibitory mechanism of tea peptides and to analyse the affinities between the peptides and the angiotensin-converting enzyme (ACE) as well as the stability of the complexes using in vitro and in silico methods. Four peptide sequences identified from tea, namely peptides I, II, III, and IV, were used to examine ACE inhibition and kinetics. The half maximal inhibitory concentration (IC₅₀) values of the four peptides were (210.03±18.29), (178.91±5.18), (196.31±2.87), and (121.11±3.38) μmol/L, respectively. The results of Lineweaver-Burk plots showed that peptides I, II, and IV inhibited ACE activity in an uncompetitive manner, which requires the presence of substrate. Peptide III inhibited ACE in a non-competitive manner, for which the presence of substrate is not necessary. The docking simulations showed that the four peptides did not bind to the active sites of ACE, indicating that the four peptides are allosteric inhibitors. The binding free energies calculated from molecular dynamic (MD) simulation were -72.47, -42.20, -52.10, and -67.14 kcal/mol (1 kcal=4.186 kJ), respectively. The lower IC₅₀ value of peptide IV may be attributed to its stability when docking with ACE and changes in the flexibility and unfolding of ACE. These four bioactive peptides with ACE inhibitory ability can be incorporated into novel functional ingredients of black tea.

Dairy-originated digestion-resistant and bioactive peptides increase the risk of hypertension: Tehran Lipid and Glucose Study

Milk-protein-derived bioactive peptides (BPs) have been proposed as modulators of different regulatory processes involved in blood pressure regulation. Studies on the long-term effects of BPs on blood pressure have not yet been conducted. We aimed to investigate the association of dairy-originated BPs with the risk of hypertension (HTN) in the Tehran Lipid and Glucose Cohort Study (TLGS). In this cohort study, 4378 subjects with a mean follow-up period of 3.1 years were included in the final analysis. Dietary intake, physical activity, demographic, and anthropometric data and blood pressure measurements were obtained for all participants. Various types of dairy-originated BPs were determined by an in silico method. High intake of total digestion-resistant and bioactive peptides (OR: 1.31, CI 95%: 1.01-1.70), dipeptides (OR: 1.33, CI 95%: 1.03-1.73), peptides with more than seven residues (OR: 1.32, CI 95%: 1.01-1.71), glycosylated residues (OR: 1.39, CI 95%: 1.07-1.80), highly hydrophilic peptides (OR: 1.32, CI 95%: 1.01-1.71), and low hydrophobic peptides (OR: 1.32, CI 95%: 1.01-1.71) was associated with an increased risk of HTN in the adjusted model. In addition, subjects in the higher tertile of anti-HTN peptide (OR: 1.33, CI 95%: 1.02-1.72) and antidiabetic peptide (OR: 1.35, CI 95%: 1.04-1.76) intake had a higher risk of HTN than those in the lower tertile. No significant association emerged between calcium intake from dairy and incident risk of HTN. Our results showed that the intake of some forms of digestion-resistant and BPs, such as anti-HTN peptides, dipeptides, and peptides with more than seven residues, can increase the risk of HTN in the TLGS population.

Investigation on the characteristics and mechanisms of ACE inhibitory peptides by a thorough analysis of all 8000 tripeptides via binding free energy calculation

Food-derived angiotensin I-converting enzyme (ACE) inhibitory peptides represent a potential source of new antihypertensive. However, their characteristics and binding mechanisms were not well understood. In this study, novel energy calculation and experimentation were combined to elucidate the characteristics and mechanisms of ACE inhibitory tripeptides. ACE inhibitory activity of all 8,000 tripeptides was investigated by in silico experiments. IC50 values of the five top-rated tripeptides ranged from 5.86 to 21.84 μM. Five hundred top-ranked tripeptides were chosen for detailed structure-activity analysis, and a significant preference for aromatic amino acids at both C- and N-terminus was found. By binding free energy analysis of nine representative tripeptides via MM/GBSA, electrostatic energy was found to be the leading energy that contributed to the binding of ACE with its high affinity tripeptides. Besides, S355, V380, and V518, three residues positioned around the classical binding pockets of ACE, also played a key role in ACE's binding. Therefore, for tripeptides, their binding pockets in ACE were redefined. In conclusion, the characteristics of ACE inhibitory peptides were more deeply illustrated by the thorough analysis of all tripeptides. The energy analysis allows a better understanding of the binding mechanisms of ACE inhibitory peptides, which could be used to redesign the ACE inhibitors for stronger inhibitory activity.

Investigation of Chlorella pyrenoidosa Protein as a Source of Novel Angiotensin I-Converting Enzyme (ACE) and Dipeptidyl Peptidase-IV (DPP-IV) Inhibitory Peptides

Chlorella pyrenoidosa (C. pyrenoidosa) is a microalgae species with a remarkably high protein content that may potentially become a source of hypotensive and hypoglycemic peptides. In this study, C. pyrenoidosa proteins were extracted and hydrolyzed overnight with pepsin and trypsin with final degrees of hydrolysis of 18.7% and 35.5%, respectively. By LC-MS/MS, 47 valid peptides were identified in the peptic hydrolysate (CP) and 66 in the tryptic one (CT). At the concentration of 1.0 mg/mL, CP and CT hydrolysates inhibit in vitro the angiotensin-converting enzyme (ACE) activity by 84.2 ± 0.37% and 78.6 ± 1.7%, respectively, whereas, tested at cellular level at the concentration of 5.0 mg/mL, they reduce the ACE activity by 61.5 ± 7.7% and 69.9 ± 0.8%, respectively. At the concentration of 5.0 mg/mL, they decrease in vitro the DPP-IV activity by 63.7% and 69.6% and in Caco-2 cells by 38.4% and 42.5%, respectively. Short peptides (≤10 amino acids) were selected for investigating the potential interaction with ACE and DPP-IV by using molecular modeling approaches and four peptides were predicted to block both enzymes. Finally, the stability of these peptides was investigated against gastrointestinal digestion.

Accurate prediction for adsorption rate of peptides with high ACE-inhibitory activity from sericin hydrolysate on thiophene hypercross-linked polymer using CoMSIA in 3D-QSAR model

Efficient screening of angiotensin converting enzyme inhibitory (ACE-I) peptides from agricultural or edible sources attract increasing attention. However, their purification process from the complex natural system is still semi-empirical or even uncontrollable, which has seriously reduced their screening efficiency. Herein, inspired by the prediction of ACE-I activity, 3D-QSAR was proposed to predict the adsorption performance of peptides from sericin hydrolysate (SH) having high ACE-I activity on porous hypercross-linked polymers according to their molecular structures. Thiophene hypercross-linked polymer (T-HCP) possessing better screening capacity for ACE-I peptides was chosen as our research object in this work. The sequence and relative adsorption rate of 101 peptides in SH were analyzed by LC-MS and was used as a database to construct the relationship of peptide's chemical structure and adsorption performance on T-HCP by Comparative molecular similarity indices analysis (CoMSIA) from 3D-QSAR. Optimum CoMSIA revealed that enhanced interaction of hydrophobicity and H-bond between T-HCP and the peptide was conducive to increase the adsorption performance of di- to hexa- peptides. Based on these relationships, the adsorption capability of 24 designed peptides with distinguished hydrophobic and H-bond fields was predicted on T-HCP by using optimum CoMSIA and the results of half of these were verified, which showed high consistency with their predicted adsorption rate. Interestingly, these peptides having higher adsorption capacities on T-HCP also possessed higher ACE-I activity. This can be attributed to the high concentration of aromatic surface with π-π interaction and weak-polar CSC group with H-bond interaction on T-HCP material, which is ideal for the selective adsorption of peptides with higher ACE-I activity from SH. This study provides important theoretical guidance for the industrial screening of bio-functional peptides from complex protein mixtures.

Sestrin 2, a potential star of antioxidant stress in cardiovascular diseases

Physiological reactive oxygen species (ROS) play an important role in cellular signal transduction. However, excessive ROS is an important pathological mechanism in most cardiovascular diseases (CVDs), such as myocardial aging, cardiomyopathy, ischemia/reperfusion injury (e.g., myocardial infarction) and heart failure. Programmed cell death, hypertrophy and fibrosis may be due to oxidative stress. Sestrin 2 (Sesn2), a stress-inducible protein associated with various stress conditions, is a potential antioxidant. Sesn2 can suppress the process of heart damage caused by oxidative stress, promote cell survival and play a key role in a variety of CVDs. This review discusses the effect of Sesn2 on the redox signal, mainly via participation in the signaling pathway of nuclear factor erythroid 2-related factor 2, activation of adenosine monophosphate-activated protein kinase and inhibition of mammalian target of rapamycin complex 1. It also discusses the effect of Sesn2's antioxidant activity on different CVDs. We speculate that Sesn2 plays an important role in CVDs by stimulating the process of antioxidation and promoting the adaptation of cells to stress conditions and/or the environment, opening a new avenue for related therapeutic strategies.

MRI study of cerebral blood flow, vascular reactivity, and vascular coupling in systemic hypertension

Chronic hypertension alters cerebrovascular function, which can lead to neurovascular pathologies and increased susceptibility to neurological disorders. The purpose of this study was to utilize in vivo MRI methods with corroborating immunohistology to evaluate neurovascular dysfunction due to progressive chronic hypertension. The spontaneously hypertensive rat (SHR) model at different stages of hypertension was studied to evaluate: i) basal cerebral blood flow (CBF), ii) cerebrovascular reactivity (CVR) assessed by CBF and blood-oxygenation level dependent (BOLD) signal changes to hypercapnia, iii) neurovascular coupling from CBF and BOLD changes to forepaw stimulation, and iv) damage of neurovascular unit (NVU) components (microvascular, astrocyte and neuron densities). Comparisons were made with age-matched normotensive Wistar Kyoto (WKY) rats. In 10-week SHR (mild hypertension), basal CBF was higher (p < 0.05), CVR trended higher, and neurovascular coupling response was higher (p < 0.05), compared to normotensive rats. In 40-week SHR (severe hypertension), basal CBF, CVR, and neurovascular coupling response were reversed to similar or below normotensive rats, and were significantly different from 10-week SHR (p < 0.05). Immunohistological analysis found significantly reduced microvascular density, increased astrocytes, and reduced neuronal density in SHR at 40 weeks (p < 0.05) but not at 10 weeks (p > 0.05) in comparison to age-matched controls. In conclusion, we observed a bi-phasic basal CBF, CVR and neurovascular coupling response from early to late hypertension using in vivo MRI, with significant changes prior to changes in the NVU components from histology. MRI provides clinically relevant data that might be useful to characterize neurovascular pathogenesis on the brain in hypertension.

Prospects of cereal protein-derived bioactive peptides: Sources, bioactivities diversity, and production

Cereals account for a large proportion of the human diet and are an important source of protein. The preparation of cereal protein peptides is a good way to utilize these proteins. Cereal protein peptides have good application potential as antioxidant, antibacterial, anti-inflammatory and anticancer compounds, in lowering blood pressure, controlling blood sugar, and inhibiting thrombosis. This article reviews the literature on the functional properties, mechanisms of action, and applications of cereal protein peptides in the food industry with two perspectives, and summarizes the methods for their preparation and identification. The biologically active peptides derived from different grain proteins have varied main functional properties, which may be related to the differences in the amino acid composition and protein types of different grains. On this basis, the structure-activity relationship of cereal protein peptides was discussed. The advancement of identification technology makes the integration of bioinformatics and bioactive peptide research closer. Bioinformatics by combination of online database, computer simulation and experimental verification is helpful to in-deep study the structure-activity relationship of biologically active peptides, and improve efficiency in the process of obtaining target peptides with less cost. In addition, the application of cereal protein peptides in the food industry is also discussed.

Plasma Branched-Chain and Aromatic Amino Acids in Relation to Hypertension

Findings of the available studies regarding the roles of branched-chain amino acids (BCAAs) and aromatic amino acids (AAAs) in hypertension are inconsistent, conflicting and inconclusive. The purpose of this study was to explore and clarify the existence of any relationships of individual BCAAs and AAAs with hypertension with adjustments for potential relevant confounders. A total of 2805 healthy controls and 2736 hypertensive patients were included in the current analysis. The associations between individual amino acids and hypertension were explored by logistic regression analyses adjusted for potential confounding variables. Among the investigated amino acids, only the BCAAs showed consistently significant positive associations with hypertension in the adjusted models (p-trend < 0.05 to 0.001). However, compared with the corresponding lowest quartile of individual BCAAs, the positive association with hypertension remained significant only in the highest quartile (p < 0.01 to 0.001). We confirmed in a relatively large cohort of subjects that BCAAs, not AAAs, demonstrated consistent positive associations with hypertension. The results display the promising potential for the use of BCAAs as relevant and accessible biomarkers, and provide perspectives on interventions directed towards the reduction in plasma BCAA levels in the prevention and management of hypertension.

A Novel Angiotensin Converting Enzyme 2 (ACE2) Activating Peptide: A Reflection of 10 Years of Research on a Small Peptide Ile-Arg-Trp (IRW)

IRW (Ile-Arg-Trp) was identified as an inhibitor of angiotensin converting enzyme (ACE) from egg white protein ovotransferrin through an integrated in silico digestion and quantitative structure and activity relationship prediction in 2011. Oral administration of IRW to spontaneously hypertensive rats (SHRs) can significantly reduce blood pressure, via upregulation of ACE2, but not through the inhibition of ACE. ACE2 converts Ang II into Ang (1-7), thus lowering blood pressure via Mas receptor (MasR); coinfusion of Mas receptor antagonist A779 and IRW in SHRs abolished blood pressure-lowering effect of IRW, supporting a key role of ACE2/Ang (1-7)/MasR axis. Our ongoing study further established new roles of IRW as an antioxidant, an anti-inflammatory agent, an insulin sensitizer, and a bone cell anabolic. Future studies are warranted to understand the unique structure features of this peptide, its mechanisms of action at various targets, its bioavailability and metabolism, and its possible roles toward COVID-19.

Plant-Based Food By-Products: Prospects for Valorisation in Functional Bread Development

The industrial and small-scale processing of plant-based food materials is associated with by-products that may have a negative impact on the environment but could add value to bread-based products. The bioactivity of plant-based food by-products, their impact on the properties of functional bread, and their bioavailability/bioaccessibility leading to potential health effects when consumed was reviewed. Plant-based food by-products which may be added to bread include rice bran, wheat bran, corn bran, grape pomace/seed extract, tomato seed/skin, and artichoke stems/leaves. These by-products contain high concentrations of bioactive compounds, including phenolics, bioactive peptides, and arabinoxylan. Pre-treatment procedures, including fermentation and thermal processing, impact the properties of plant-based by-products. In most cases, bread formulated with flour from plant-based by-products demonstrated increased fibre and bioactive compound contents. In terms of the sensory and nutritional acceptability of bread, formulations with an average of 5% flour from plant-based by-products produced bread with acceptable sensory properties. Bread enriched with plant-based by-products demonstrated enhanced bioavailability and bioaccessibility and favourable bioactive properties in human blood, although long-term studies are warranted. There is a need to investigate the bioactive properties of other underutilised plant-based by-products and their potential application in bread as a sustainable approach towards improving food and nutrition security.

Chocolate desserts with ricotta hydrolysates: In vitro study of inhibitory activity against angiotensin-converting enzyme and cholinesterase

Food can be a source of valuable peptides with high bioactivity, which regulate the functioning of cardiovascular and nervous systems. The aim of the study was to evaluate the possibility of usage ricotta after hydrolysis to obtain innovative chocolate desserts. It was shown that the hydrolysis of whey proteins in ricotta had insignificant effect on the texture indices of the products, except gumminess, as it declined to 16% in ricotta samples and to 7% in case of chocolate dessert samples. Confirmed was that the hydrolysis of the ricotta affected the activity of prepared desserts with respect to cholinesterases and angiotensin-converting enzyme. Enzymatic hydrolysate of ricotta may be consider as a semifinished product of high functional activity, and its further application in dessert production allows to provide novel prohealth new products. PRACTICAL APPLICATION: Study results indicate new feasibilities of ricotta application as functional ingredient of new products--chocolate desserts. The results show that ricotta after the stage of enzyme hydrolysis of proteins might have noticeable effect on product functionality. A measurable benefit for the consumer is the receipt of a new product with favorable health-promoting properties, and for the entrepreneur new possibilities to expand the range of functional products. Moreover, described technology allows to use dairy byproducts for new products developments, such as chocolate desserts, due to sustainability development strategy.

Current genetic engineering strategies for the production of antihypertensive ACEI peptides

Hypertension is a major and highly prevalent risk factor for various diseases. Among the most frequently prescribed antihypertensive first-line drugs are synthetic angiotensin I-converting enzyme inhibitors (ACEI). However, since  their use in hypertension therapy has been linked to various side effects, interest in the application of food-derived ACEI peptides (ACEIp) as antihypertensive agents is rapidly growing. Although promising, the industrial production of ACEIp through conventional methods such as chemical synthesis or enzymatic hydrolysis of food proteins has been proven troublesome. We here provide an overview of current antihypertensive therapeutics, focusing on ACEI, and illustrate how biotechnology and bioengineering can overcome the limitations of ACEIp large-scale production. Latest advances in ACEIp research and current genetic engineering-based strategies for heterologous production of ACEIp (and precursors) are also presented. Cloning approaches include tandem repeats of single ACEIp, ACEIp fusion to proteins/polypeptides, joining multivariate ACEIp into bioactive polypeptides, and producing ACEIp-containing modified plant storage proteins. Although bacteria have been privileged ACEIp heterologous hosts, particularly when testing for new genetic engineering strategies, plants and microalgae-based platforms are now emerging. Besides being generally safer, cost-effective and scalable, these "pharming" platforms can perform therelevant posttranslational modifications and produce (and eventually deliver) biologically active protein/peptide-based antihypertensive medicines.

Two novel ACE inhibitory peptides isolated from longan seeds: purification, inhibitory kinetics and mechanisms

Angiotensin converting enzyme (ACE) inhibition offers a useful means of managing hypertension, because ACE inhibitors (ACEIs) are known to serve as agents with antihypertensive properties in addition to generating positive metabolic and cardioprotective outcomes. However, current ACEIs are linked to adverse consequences, and so there is a requirement for effective but safer compounds, which might be achieved through chemical synthesis or the isolation of naturally obtained bioactive molecules. Protein hydrolysates with ACEI activity can be produced by the combined pepsin and pancreatin proteolysis (to mimic gastrointestinal digestion) of longan seed protein. This study examined longan seed protein hydrolysates, obtained from a sequential 3 h digestion with pepsin and then pancreatin. The resulting hydrolysate underwent sequential ultrafiltration membrane fractionation with a 10, 5, and 3 kDa molecular weight cut-off (MWCO). The permeate derived from the <3 kDa MWCO demonstrated the highest ACEI activity. This permeate subsequently underwent separation by reverse-phase high performance liquid chromatography to give the main fractions on the basis of differing elution times. The ACEI IC50 values for these fractions were then identified. Quadrupole time-of-flight tandem mass spectrometry was employed to determine the peptide mass for the major peak (F 5), which was shown to be Glu-Thr-Ser-Gly-Met-Lys-Pro-Thr-Glu-Leu (ETSGMKPTEL) and Ile-Ser-Ser-Met-Gly-Ile-Leu-Val-Cys-Leu (ISSMGILVCL). These two peptides were stable over a temperature and pH range of -20 to 90 °C and 2-12, respectively, for 60 min. From the Lineweaver-Burk plot, both peptides inhibited ACE non-competitively. Molecular docking simulation of the peptides with ACE supported the formation of hydrogen bonds by the peptides with the ACE active pockets. This research indicates that it may be possible to use both of these peptides or longan seed protein hydrolysates in order to create ingredients for functional foods, or to produce pharmaceutical products, capable of lowering hypertension.

Implication of Opioid Receptors in the Antihypertensive Effect of a Bovine Casein Hydrolysate and αs1-Casein-Derived Peptides

The antihypertensive activity of two α_s1-casein-derived peptides and casein hydrolysate containing these sequences was evaluated in the presence of naloxone. The activity was abolished by this opioid antagonist at 2, 4, and 6 h post-administration. Similarly, the antihypertensive effect of the α_s1-casein peptides ⁹⁰RYLGY⁹⁴ (-23.8 ± 2.5 mmHg) and ¹⁴³AYFYPEL¹⁴⁹ (-21.1 ± 3.2 mmHg) at 5 mg/kg of body weight was antagonized by the co-administration of naloxone. Because peptide ¹⁴³AYFYPEL¹⁴⁹ had recently shown opioid activity, a molecular dynamic simulation of this peptide with human μ-opioid receptor was performed to demonstrate its favorable structure and interaction energy, despite the presence of Ala at the N terminus. Altogether, these results revealed that the in vivo effect on systolic blood pressure of the studied α_s1-casein peptides is mediated by interaction with opioid receptors and the antihypertensive activity of casein hydrolysate can be very likely ascribed to them with the possible contribution of other mechanisms.

ACE inhibitory peptides derived from de-fatted lemon basil seeds: optimization, purification, identification, structure–activity relationship and molecular docking analysis

The study determines optimized process conditions to maximize ACE inhibitory peptide production. The two novel hexa-peptides (LGRNLPPI and GPAGPAGL) from de-fatted lemon basil seeds (DLBS) was achieved.