The antihypertensive effect of peptides: a novel alternative to drugs?

Pulse protein quality and derived bioactive peptides

There is a growing consumer interest in sources of dietary protein that are plant-based. Pulse crops, such as lentils, beans, chickpeas, and peas, are gaining popularity due to their environmental sustainability, nutrient density, and functional attributes. The protein content and quality of pulses vary across different pulse classes and processing methods. The biological properties of the protein and the physiologically active peptides make pulse crops attractive as potentially functional or health-promoting foods. This review highlights the nutritional quality of pulse proteins as determined by the Protein Efficiency Ratio and Protein Digestibility Corrected Amino Acid Score as well as bioactive properties of specific bioactive peptides related to amelioration of hypertension and diabetes. Additionally, the use of proteomics platforms, such as mass spectrometry, in combination with bioinformatics tools, enables the identification and characterization of bioactive peptides in pulse crops. These technologies facilitate the development of pulse-derived products with enhanced nutritional values. Overall, the high nutritional quality of pulse-based proteins supports the benefits of pulse inclusion in the diet, which can also exert beneficial bioactivities resulting in improving outcomes in non-communicable diseases.

Enhanced antihypertensive chicken by-product hydrolysate fraction after its separation by electrodialysis with ultrafiltration membrane (EDUF)

The environmental impact of poultry industry waste has led to the study of hydrolysates with potential health-promoting properties obtained from poultry by-products and their fractionation to increase the bioactivity of these hydrolysates. The aim of the present study was to separate a chicken by-product hydrolysate (CBH) by electrodialysis with ultrafiltration membranes (EDUF), providing peptide selective separation based on their charge and molecular weight, and to characterize the resulting fractions. Experimental results showed that during the peptide fractionation process the global peptide migration rate (MR) from CBH was 14.97 ± 0.14 g/m2•h with a relative energy consumption of 31.27 ± 2.61 Wh/g of total peptides. 164 peptides were identified in the initial CBH, and following EDUF, 39 migrated to the positively charged peptide fraction (PCC) and 9 to the negatively charge peptide fraction (NCC): 21 sequences were reported as bioactive for CBH, 6 for PCC and 1 for NCC. Analyses of ACE inhibition evidenced a 1.4 fold increase in antihypertensive activity of the PCC (IC50 0.46 ± 0.04 mg peptides /mL) in comparison to CBH (IC50 0.65 ± 0. 04 mg peptides /mL), despite the smaller number of bioactive sequences reported and the fact that it is possible to enhance the PCC recovery by modifying the EDUF configuration in further studies. These findings highlight the significance of EDUF as a sustainable method for obtaining specifically charged peptide fractions with enhanced bioactivity from the initial hydrolysate.

Cross talk on therapeutic strategies: natriuretic peptides and inhibiting neprilysin in hypertension management

Hypertension, a prevalent cardiovascular condition globally, remains a significant public health concern due to its association with increased cardiovascular morbidity and mortality. Despite the availability of various antihypertensive therapies, achieving optimal blood pressure control in patients remains a challenge. Valsartan/sacubitril (ARNi), marketed as Entresto by Novartis, combines valsartan, an angiotensin receptor blocker, with sacubitril, an inhibitor of neprilysin. Neprilysin is responsible for breaking down natriuretic peptides and other vasoactive substances. Inhibiting neprilysin prevents the degradation of natriuretic peptides, enhancing their beneficial effects on blood pressure regulation. Natriuretic Peptides, including atrial natriuretic peptide (ANP) and brain natriuretic peptides (BNP), play pivotal roles in regulating blood pressure and cardiovascular homeostasis by promoting vasodilation, natriuresis, and antagonizing the renin-angiotensin-aldosterone system. Therefore, this combo drug lessens sensitivity to natriuretic peptides and tackles the processes in hypertension that activate the renin-angiotensin-aldosterone system. This review provides an overview of how natriuretic peptides (NPs) contribute to blood pressure regulation for the treatment of hypertension through inhibiting neprilysin. It highlights the ARNi's dual action that works synergistically by blocking the harmful effects of angiotensin II on blood vessels while simultaneously increasing the levels of beneficial natriuretic peptides. Schematic representation of the mechanism of action of ARNi. Abbreviation: -Renin angiotensin aldosterone system (RAAS), Natriuretic peptides (NP), Atrial Natriuretic peptide (ANP), Brain natriuretic peptide (BNP), C-type natriuretic peptide (CNP), Angiotensin II (Ang II), Angiotensin receptor neprilysin inhibitor (ARNI).

DeepForest-HTP: A novel deep forest approach for predicting antihypertensive peptides

Hypertension is a major preventable risk factor for cardiovascular disease, affecting over 1.5 billion adults worldwide. Antihypertensive peptides (AHTPs) have gained attention as a natural therapeutic option with minimal side effects. This study proposes a Deep Forest-based machine learning framework for AHTP prediction, leveraging a multi-granularity cascade structure to enhance classification accuracy. We integrated data from BIOPEP-UWM and three previously used datasets, totaling 2000 peptide sequences, and introduced novel feature extraction methods to build a comprehensive dataset for model training. This study represents the first application of Deep Forest for AHTP identification, demonstrating substantial classification performance advantages over traditional methods (e.g., SVM, CNN, and XGBoost) as well as recent mainstream prediction models (Ensemble-AHTPpred, CNN-SVM Ensemble, and mAHTPred). Requiring no complex manual feature engineering, the model adapts flexibly to various data needs, offering a novel perspective for efficient AHTP prediction and promising utility in hypertension management. On the benchmark dataset, the model achieved high accuracy, sensitivity, and AUC, providing a robust tool for identifying safe and effective AHTPs. However, future efforts should incorporate larger and more diverse independent validation datasets to further improve the model and enhance its generalizability. Additionally, the model's predictive accuracy relies on known AHTP targets and sequence features, potentially limiting its ability to detect AHTPs with uncharacterized or atypical properties.

Angiotensin converting enzyme (ACE) inhibitory peptide from the tuna (Thunnus thynnus) muscle: Screening, interaction mechanism and stability

In this study, the purpose was to screen novel angiotensin converting enzyme inhibitory peptides (ACEIPs) from tuna muscle taking two-steps enzymatic hydrolysis (Neutrase and Alkaline). Following isolation and purification by ultrafiltration, the Sephadex G-15 gel chromatography and reversed-phase high-performance liquid chromatography based on active-guide, the amino acid sequence was identified using Q-Orbitrap-MS/MS. Five peptides were chose synthesized based on the in silico screening methods. Among these, the two novel ACEIPs LTGCP and YPKP showed better inhibitory ability, and their corresponding IC50 values were 64.3 μM and 139.6 μM. Subsequently, the interaction mechanism of the best active peptide (LTGCP) against ACE was investigated by inhibitory pattern, molecular docking and molecular dynamic simulation. The result displayed that LTGCP was a mix-type inhibitor against ACE from the Lineweaver-Burk plots. LTGCP formed seven hydrogen bonds based on the molecular docking and the binding energy was -7.29 kcal/mol. LTGCP formed a stability complex with ACE based on the molecular dynamic simulation. Besides, LTGCP exhibited good stability in various temperature, pH and gastrointestinal digestion. Finally, the 0.125 mM ∼ 1.0 mM LTGCP exhibited no-toxic for Caco-2 cell. In summary, these findings showed that tuna was a good material to prepare ACEIPs and LTGCP may be the good potential antihypertensive drug or nutraceuticals.

Purification of angiotensin converting enzyme inhibitory peptides and antihypertensive effect generated from Indonesian traditional fermented beef (Cangkuk)

OBJECTIVE

Traditional fermented meat products can be considered a source of bioactive peptides. Cangkuk, a traditional Indonesian fermented beef product is one source of angiotensin converting enzyme (ACE) inhibitory peptides. This study aimed to identify ACE-inhibitory peptides from Cangkuk and analyze their antihypertensive effects.

METHODS

The water-soluble fraction of Cangkuk was fractionated to obtain ACE-inhibitory peptides using an ethanol solvent at several concentrations and solid-phase extraction with an OASIS HLB cartridge followed by purification with reversed-phase high-performance liquid chromatography (RP-HPLC). HPLC-MS was used to identify target peptides, followed by automatic protein sequencer analysis to detect peptide sequences. Antihypertensive effects were analyzed on the water-soluble fraction and synthesized peptides. The animal model comprised 14-16-week-old male spontaneously hypertensive rats (SHRs) (~320 g average body weight) with mean systolic blood pressures (SBPs) higher than 190 mmHg. All oral doses of peptides were 1 mL in volume. Distilled water was used as a control. The antihypertensive activities of the sample and control were observed by measuring the SBP at 0, 2, 4, 6, 8 and 24 h after oral administration.

RESULTS

Two sequences of ACE inhibitory peptides were found, EAPLNPKANR (IC50 value of 44.6 μmol/L) and IVG (IC50 value of 97.3 μmol/L). The water-soluble fraction demonstrated an antihypertensive effect on SHRs after oral administration at 100 mg/kg body weight, maximally lowering the SBP by 14.9 mmHg 8 h after administration. The tripeptide IVG showed the highest reduction of SBP, 24.76±2.1 mmHg 8 h after administration. The decapeptide EAPLNPKANR showed the highest reduction of SBP, 21.0±1.9 mmHg, 8 h after administration. All the samples differed significantly from the control (p<0.01).

CONCLUSION

Cangkuk has potential as a functional food ingredient acting as an antihypertensive agent.

In silico and in vivo experiment of soymilk peptide (tetrapeptide - FFYY) for the treatment of hypertension

Enzyme-Treated Soymilk (ETS) was produced from Commercial Soymilk (CSM) with the treatment of proteinase PROTIN SD-NY10 (Bacillus amyloliquefaciens). Previously, we have isolated novel peptides from ETS but data related to isolated-peptides are scant. In this study, bio-informatics and in vivo analysis of isolated-peptides showed strong binding affinity to the active site of the Angiotensin Converting Enzyme (ACE). Among four peptides, tetrapeptide Phe-Phe-Tyr-Tyr (FFYY) showed strong binding affinity and inhibitory activity to the ACE-enzyme (binding affinity -9.5 Kcal/mol and inhibitory concentration of 1.9 µM respectively) as well as showed less toxicity compared to other peptides. The animal experiment revealed that single oral dose of FFYY (80 µg/kg body weight/day) effectively ameliorates the systolic, diastolic and mean blood pressure in the spontaneously hypertensive rat (SHR) model. Chronic oral administration of FFYY (80 µg/kg body weight/day for 3 weeks) reduced the systolic blood pressure elevation and ACE activity without any adverse side effects on the physiological and biological parameters of SHR. In conclusion, both in silico and in vivo experiments of soymilk-isolated FFYY peptide showed a promising option as a potential alternative for hypertension treatment without adverse side effects on SHR.

Effects of Egg Consumption on Subjects with SLD or Hypertension: A MICOL Study

BACKGROUND

Steatotic liver disease (SLD) is defined as a fat accumulation in more than 5% of hepatocytes; it can progress to non-alcoholic steatohepatitis (NASH), associated with an increased state of inflammation. The aim of this study was to explore the protective effects of eating eggs and any association with SLD and hypertension (HTN).

METHODS

The study cohort included 908 participants assessed in the fourth recall of the MICOL study, grouped into four groups, based on NALFD and/or HTN.

RESULTS

The prevalence of HTN and SLD among participants was 31.61%. Overall, the results indicated a statistical significance of egg consumption, showing a protective role against the two disease conditions, in both the raw and adjusted models (RRR = 0.34, p = 0.009, 0.15 to 0.76 95% C.I.).

CONCLUSIONS

Many differences were found among the groups, and the protective role of eating eggs was amply demonstrated. We can conclude that it is unwise to demonize the intake of this food and its nutritional properties, in contrast with previous reports in the literature.

Impact of Air-Drying Temperature on Antioxidant Properties and ACE-Inhibiting Activity of Fungal Fermented Lentil Flour

Solid-state fermentation (SSF) with Pleurotus ostreatus enhances the nutritional value of legumes. However, drying can cause significant changes in physical and nutritional properties of the final products. Thus, this work studies the impact of air-drying temperature (50, 60, and 70 °C) on relevant properties (antioxidant properties, ACE-inhibitory capacity, phytic acid, colour, and particle size) of two fermented lentils flour (Pardina and Castellana) using freeze-drying as a reference method. Castellana variety is a better substrate for Pleurotus, generating four times more biomass. In addition, an almost total reduction of phytic acid from 7.3 to 0.9 mg/g db is achieved in this variety. Air-drying significantly decreased the particle size and the final colour with ΔE > 20; nonetheless, the temperature does not play a crucial role. SSF decreased the total phenolic content and the antioxidant capacity regardless of the variety, however, drying at 70 °C increased total phenolic content (186%) in fermented Castellana flour. Comparing drying methods, freeze-drying implied a higher decrease in those parameters, reducing the TPC from 2.4 to 1.6 and from 7.7 to 3.4 mg gallic acid/g db in Pardina and Castellana dried flours. Finally, the flours inhibit the angiotensin I-converting-enzyme, and fermentation and drying increased their potential cardiovascular benefits.

Prediction and Evaluation of Bioactive Properties of Cowpea Protein Hydrolysates

Cowpea protein hydrolysates were prepared using thermolysin, alcalase, and trypsin and analysed for bioactive properties, and then, the release of bioactive peptides was investigated in silico. It was found that the degree of hydrolysis reached 48% after 24 h hydrolysis with alcalase. The hydrolysate prepared using alcalase showed higher ACE inhibitory (62%) and DPPH scavenging activity (19%). SDS-PAGE analysis revealed that vignin was the major protein in cowpea protein isolate. In silico analysis indicated the presence of potential bioactive peptides with potent bioactivity in the primary structure of proteins. The 3D structure of proteins was built, upon which bioactive peptides were mapped using their location in the primary structure. The secondary structure and solvent accessible surface around each bioactive peptide were then calculated. On this basis, the higher degree of hydrolysis and bioactive properties of cowpea protein hydrolysate prepared by alcalase were explained, and structural factors influencing the release of bioactive peptides were investigated.

Purification and Characterization of Novel Antihypertensive and Antioxidative Peptides From Whey Protein Fermentate: In Vitro, In Silico, and Molecular Interactions Studies

OBJECTIVE

The goal of this research was to purify and characterize the novel angiotensin-converting enzyme (ACE)-inhibitory and antioxidant peptides from fermented whey protein concentrate produced by Lactobacillus paracasei and Saccharomyces cerevisiae in a co-fermentation system.

METHOD

Whey protein fermented with lactic acid bacteria and yeast culture was analyzed for antioxidative, ACE inhibition, as well as anti-inflammatory activity followed by SDS-PAGE, isoelectric focusing, and 2-dimensional (2D) analysis. Anti-inflammatory activity of whey protein fermentate was also studied on the RAW 264.7 cell line. The bioactive peptides were separated from the whey protein fermentate using reverse-phase high-performance liquid chromatography (RP-HPLC) and reverse-phase liquid chromatography mass spectrometry (RPLC/MS), and thus identification and characterization of purified bioactive peptide was performed.

RESULTS

Whey protein fermentate samples' bioactivity was analyzed at specific time intervals at 12, 24, 36, and 48 hours at 37 °C for M11 and at 25 °C for WBS2A. The development settings (incubation time [12, 24, 36, and 48 hours) and inoculation rates [1.5%, 2.0%, and 2.5%]) were optimized for peptide synthesis via the o-phthaldialdehyde (OPA) method (proteolytic activity). Maximum proteolytic activity was observed at 37 °C for M11 (6.50 mg/mL) and at 25 °C for WBS2A (8.59 mg/mL) for 48 hours of incubation. Protein profiling was carried out using SDS-PAGE and 2D gel electrophoresis, in which Sodium dodecyl-sulfate (SDS) exhibited protein bands in the 10- to 55-kDa range, while 2D showed protein bands varying from 10 to 70 kDa. Every spot from 2D was digested by trypsin and identified by RPLC/MS. Protein fractionations (3- and 10-kDa permeates) were carried out employing RP-HPLC. Whey protein fermentate has anti-inflammatory action in RAW 264.7 macrophages that have been exposed to lipopolysaccharide. A molecular docking system was also used to investigate the interactions of peptides (AFLDSRTR, ILGAFIQIITFR) with human myeloperoxidase enzyme.

CONCLUSIONS

The antihypertensive and antioxidative peptides discovered from whey protein fermentate may be helpful in the design of pharmacologically active healthy ingredients in the upcoming years.

First Report of Screening of Novel Angiotensin-I Converting Enzyme Inhibitory Peptides Derived from the Red Alga Acrochaetium sp

ACE inhibitors generated from food proteins have recently become the most well-known subclass of bioactive peptides, and their bio-functionality can be a potential alternative to natural bioactive food components and synthetic drugs. The bioactivities of Acrochaetium sp., the red alga used in this investigation, have never been reported before. Screening of bioactive peptides from Acrochaetium sp. as ACE inhibitors were hydrolyzed with various proteolytic enzymes. Protein hydrolysates were fractionated separately using reversed phased (RP) and strong cation exchange (SCX) chromatography and identified as VGGSDLQAL (VL-9) using α-chymotrypsin. It comes from Phycoerythrin (PE), an abundant protein in a primarily red alga. The peptide VL-9 shows the ACE inhibitory activity with IC₅₀ value 433.1 ± 1.08 µM. The inhibition pattern showed VL-9 as a non-competitive inhibitor. Molecular docking simulation proved that VL-9 was non-competitive inhibition due to the interaction peptide and ACE was not in the catalytic site. Moreover, VL-9 derived from Acrochaetium sp. is a natural bioactive peptide that is safer and available for food protein; also, the ACE inhibitory peptide derived from Acrochaetium sp. could be the one alternative resource to develop functional food for combating hypertension.

Enhancing the Biological Activities of Food Protein-Derived Peptides Using Non-Thermal Technologies: A Review

Bioactive peptides (BPs) derived from animal and plant proteins are important food functional ingredients with many promising health-promoting properties. In the food industry, enzymatic hydrolysis is the most common technique employed for the liberation of BPs from proteins in which conventional heat treatment is used as pre-treatment to enhance hydrolytic action. In recent years, application of non-thermal food processing technologies such as ultrasound (US), high-pressure processing (HPP), and pulsed electric field (PEF) as pre-treatment methods has gained considerable research attention owing to the enhancement in yield and bioactivity of resulting peptides. This review provides an overview of bioactivities of peptides obtained from animal and plant proteins and an insight into the impact of US, HPP, and PEF as non-thermal treatment prior to enzymolysis on the generation of food-derived BPs and resulting bioactivities. US, HPP, and PEF were reported to improve antioxidant, angiotensin-converting enzyme (ACE)-inhibitory, antimicrobial, and antidiabetic properties of the food-derived BPs. The primary modes of action are due to conformational changes of food proteins caused by US, HPP, and PEF, improving the susceptibility of proteins to protease cleavage and subsequent proteolysis. However, the use of other non-thermal techniques such as cold plasma, radiofrequency electric field, dense phase carbon dioxide, and oscillating magnetic fields has not been examined in the generation of BPs from food proteins.

Utility of a Hydrolysate from Overproduced Paralichthys olivaceus for Hypertension Treatment: Correlation between Physical Properties and Potent Anti-Hypertensive Activities

Aquacultured fish are the richest natural source of protein. However, their overproduced biomass is often discarded due to production imbalance, causing considerable losses to the fishery industry. Therefore, it is necessary to utilize surplus fish and add value to overproduced fish. We performed complex enzyme-assisted hydrolysis to determine the correlation between its physical characteristics and anti-hypertensive activity in vitro and in vivo using an SHR model. Protamex-Pepsin assisted hydrolysate from Paralichthys olivaceus (PO_ppH) produced by complex enzyme-assisted hydrolysis contained low-molecular-weight peptides and amino acids with anti-hypertensive activity. PO_ppH regulated blood pressure and serum angiotensin II and angiotensin-I-converting enzyme levels, and histological and ultrasound image analysis revealed substantially reduced thickness and diameter of the carotid aorta in the PO_ppH-administered SHR group. Therefore, we propose to reduce food loss due to overproduction by utilizing the anti-hypertensive activity and physical properties of PO_ppH; the results demonstrate its application as a therapeutic agent.

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.

Impact of solid-state fermentation on factors and mechanisms influencing the bioactive compounds of grains and processing by-products

Cereal and legume grains and their processing by-products are rich sources of bioactives such as phenolics with considerable health potential, but these bioactives suffer from low bioaccessibility and bioavailability, resulting in limited use. Several studies have demonstrated that solid-state fermentation (SSF) with food-grade microorganisms is effective in releasing bound phenolic compounds in cereal and legume products. In this review, we discuss the effect of SSF on cereal and legume grains and their by-products by examining the role of specific microorganisms, their hydrolytic enzymes, fermentability of agri-food substrates, and the potential health benefits of SSF-enhanced bioactive compounds. SSF with fungi (Aspergillus spp. and Rhizopus spp.), bacteria (Bacillus subtilis and lactic acid bacteria (LAB) spp.) and yeast (Saccharomyces cerevisiae) significantly increased the bioactive phenolics and antioxidant capacities in cereal and legume grains and by-products, mainly through carbohydrate-cleaving enzymes. Increased bioactive phenolic and peptide contents of SSF-bioprocessed cereal and legume grains have been implicated for improved antioxidant, anti-inflammatory, anti-carcinogenic, anti-diabetic, and angiotensin-converting-enzyme (ACE) inhibitory effects in fermented agri-food products, but these remain as preliminary results. Future research should focus on the microbial mechanisms, suitability of substrates, and the physiological health benefits of SSF-treated grains and by-products.

Nutraceutical potential of mushroom bioactive metabolites and their food functionality

Numerous mushroom bioactive metabolites, including polysaccharides, eritadenine, lignin, chitosan, mevinolin, and astrakurkurone have been studied in life-threatening conditions and diseases such as diabetes, cardiovascular, hypertension, cancer, DNA damage, hypercholesterolemia, and obesity attempting to identify natural therapies. These bioactive metabolites have shown potential as antiviral and immune system strengthener natural agents through diverse cellular and physiological pathways modulation with no toxicity evidence, widely available, and inexpensive. In light of the emerging literature, this paper compiles the most recent information describing the molecular mechanisms that underlie the nutraceutical potentials of these mushroom metabolites suggesting their effectiveness if combined with existing drug therapies while discussing the food functionality of mushrooms. The findings raise hope that these mushroom bioactive metabolites may be utilized as natural therapies considering their therapeutic potential while anticipating further research designing clinical trials and developing new drug therapies while encouraging their consumption as a natural adjuvant in preventing and controlling life-threatening conditions and diseases. PRACTICAL APPLICATIONS: Diabetes, cardiovascular, hypertension, cancer, DNA damage, hypercholesterolemia, and obesity are among the world's largest life-threatening conditions and diseases. Several mushroom bioactive compounds, including polysaccharides, eritadenine, lignin, chitosan, mevinolin, and astrakurkurone have been found potential in tackling these diseases through diverse cellular and physiological pathways modulation with no toxicity evidence, suggesting their use as nutraceutical foods in preventing and controlling these life-threatening conditions and diseases.

Bio-therapeutics from human milk: prospects and perspectives

Human milk is elixir for neonates and is a rich source of nutrients and beneficial microbiota required for infant growth and development. Its benefits prompted research into probing the milk components and their use as prophylactic or therapeutic agents. Culture-independent estimation of milk microbiome and high-resolution identification of milk components provide information, but a holistic purview of these research domains is lacking. Here, we review the current research on bio-therapeutic components of milk and simplified future directions for its efficient usage. Publicly available databases such as PubMed and Google scholar were searched for keywords such as probiotics and prebiotics related to human milk, microbiome and milk oligosaccharides. This was further manually curated for inclusion and exclusion criteria relevant to human milk and clinical efficacy. The literature was classified into subgroups and then discussed in detail to facilitate understanding. Although milk research is still in infancy, it is clear that human milk has many functions including protection of infants by passive immunization through secreted antibodies, and transfer of immune regulators, cytokines and bioactive peptides. Unbiased estimates show that the human milk carries a complex community of microbiota which serves as the initial inoculum for establishment of infant gut. Our search effectively screened for evidence that shows that milk also harbours many types of prebiotics such as human milk oligosaccharides which encourage growth of beneficial probiotics. The milk also trains the naive immune system of the infant by supplying immune cells and stimulatory factors, thereby strengthening mucosal and systemic immune system. Our systematic review would improve understanding of human milk and the inherent complexity and diversity of human milk. The interrelated functional role of human milk components especially the oligosaccharides and microbiome has been discussed which plays important role in human health.

A Systemic Review on Microalgal Peptides: Bioprocess and Sustainable Applications

Nowadays, microalgal research is predominantly centered on an industrial scale. In general, multipotent bioactive peptides are the advantages over focal points over utilitarian nourishment as well as nutraceuticals. Microalgal peptides are now profoundly connected with biological properties rather than nutritive. Numerous techniques are employed to purify active peptides from algal protein using enzymatic hydrolysis; it is broadly used for numerous favorable circumstances. There is a chance to utilize microalgal peptides for human well-being as nutritive enhancements. This exhaustive survey details the utilization of microalgal peptides as antioxidant, anti-cancerous, anti-hypersensitive, anti-atherosclerotic, and nutritional functional foods. It is also exploring the novel technologies for the production of active peptides, for instance, the use of algal peptides as food for human health discovered restrictions, where peptides are sensitive to hydrolysis protease degradation. This review emphasizes the issue of active peptides in gastrointestinal transit, which has to be solved in the future, and prompt impacts.

Boosted Prediction of Antihypertensive Peptides Using Deep Learning

Heart attack and other heart-related diseases are among the main causes of fatalities in the world. These diseases and some other severe problems like kidney failure and paralysis are mainly caused by hypertension. Since bioactive peptides extracted from naturally existing food substances possess antihypertensive activity, these antihypertensive peptides (AHTP) can function as prospective replacements for existing pharmacological drugs with no or fewer side effects. Such naturally existing peptides can be identified using in-silico approaches. The in-silico methods have been proven to save huge amounts of time and money in the identification of effective peptides. The proposed methodology is a deep learning-based in-silico approach for the identification of antihypertensive peptides (AHTPs). An ensemble method is proposed that combines convolutional neural network (CNN) and support vector machine (SVM) classifiers. Amino acid composition (AAC) and g-gap dipeptide composition (DPC) techniques are used for feature extraction. The proposed methodology has been evaluated on two standard antihypertensive peptide sequence datasets. The model yields 95% accuracy on the benchmarking dataset and 88.9% accuracy on the independent dataset. Comparative analysis is provided to demonstrate that the proposed method outperforms existing state-of-the-art methods on both of the benchmarking and independent datasets.

Antioxidant properties and inhibition of angiotensin-converting enzyme by highly active peptides from wheat gluten

This study aimed to focus on the high-value utilization of raw wheat gluten by determining the potent antioxidant peptides and angiotensin I-converting enzyme (ACE) inhibitory peptides from wheat gluten oligopeptides (WOP). WOP were analyzed for in vitro antioxidant activity and inhibition of ACE, and the identification of active peptides was performed by reversed-phase high-performance liquid chromatography and mass spectrometry. Quantitative analysis was performed for highly active peptides. Five potent antioxidant peptides, Leu-Tyr, Pro-Tyr, Tyr-Gln, Ala-Pro-Ser-Tyr and Arg-Gly-Gly-Tyr (6.07 ± 0.38, 7.28 ± 0.29, 11.18 ± 1.02, 5.93 ± 0.20 and 9.04 ± 0.47 mmol 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox) equivalent/g sample, respectively), and five potent ACE inhibitory peptides, Leu-Tyr, Leu-Val-Ser, Tyr-Gln, Ala-Pro-Ser-Tyr and Arg-Gly-Gly-Tyr (half maximal inhibitory concentration (IC50) values = 0.31 ± 0.02, 0.60 ± 0.03, 2.00 ± 0.13, 1.47 ± 0.08 and 1.48 ± 0.11 mmol/L, respectively), were observed. The contents of Leu-Tyr, Pro-Tyr, Tyr-Gln, Ala-Pro-Ser-Tyr, Arg-Gly-Gly-Tyr, and Leu-Val-Ser were 155.04 ± 8.36, 2.08 ± 0.12, 1.95 ± 0.06, 22.70 ± 1.35, 0.25 ± 0.01, and 53.01 ± 2.73 μg/g, respectively, in the WOP. Pro-Tyr, Tyr-Gln, Ala-Pro-Ser-Tyr, Arg-Gly-Gly-Tyr, and Leu-Val-Ser are novel antioxidative/ACE inhibitory peptides that have not been previously reported. The results suggest that WOP could potentially be applied in the food industry as a functional additive.

Effect of ripening time on peptide dynamics and bioactive peptide composition in Tulum cheese

Skin bag Tulum cheeses traditionally produced in the Central Taurus region of Turkey were studied to identify peptide profiles by liquid chromatography-tandem mass spectrometry over 180 d of ripening. After mass spectrometry analysis, 203 peptides were identified: 59 from α_S1-casein (CN), 11 from α_S2-CN, 129 from β-CN, and 4 from κ-CN. Numbers of α_S1- and β-CN-derived peptides increased with increasing number of ripening days due to the dependence of newly formed peptides on proteolysis. However, similar increases were not observed for α_S2- and κ-CN-derived peptides. Most identified peptides consisted of β-CN-derived peptides, followed by α_S1-, α_S2-, and κ-CN-derived peptides. Among these, bioactive peptides were found, including antihypertensive, antibacterial, antioxidant, dipeptidyl peptidase-4 inhibitory, metal chelating, skin regenerating, glucagon-like peptide-1 secretion enhancing, opioid, cathepsin B inhibitory, prolyl endopeptidase inhibitory, immunomodulatory, brain function improving, antiamnesic, antihypercholesterolemic, anti-inflammatory, and anticarcinogenic peptides.

Activity and bioavailability of food protein-derived angiotensin-I-converting enzyme-inhibitory peptides

Angiotensin-I-converting enzyme (ACE) inhibitory peptides are able to inhibit the activity of ACE, which is the key enzymatic factor mediating systemic hypertension. ACE-inhibitory peptides can be obtained from edible proteins and have the function of antihypertension. The amino acid sequences and the secondary structures of ACE-inhibitory peptides determine the inhibitory activities and stability. The resistance of ACE-inhibitory peptides to digestive enzymes and peptidase affect their antihypertensive bioactivity in vivo. In this paper, the mechanism of ACE-inhibition, sources of the inhibitory peptides, structure-activity relationships, stability during digestion, absorption and transportation of ACE-inhibitory peptides, and consumption of ACE-inhibitory peptides are reviewed, which provide guidance to the development of new functional foods and production of antihypertensive nutraceuticals and pharmaceuticals.

A multifunctional ingredient for the management of metabolic syndrome in cafeteria diet-fed rats

The body weight-lowering properties of a multifunctional ingredient (MIX) based on conjugated linoleic acid at low doses, the flavonoids proanthocyanidins and anthocyanidins and the chicken feet hydrolysate Hpp11 have been previously reported. The aim of this study was to evaluate the effect of long-term administration of MIX on other cardiometabolic risk factors associated with metabolic syndrome (MetS) in rats fed a cafeteria diet (CAF). Male Wistar rats were fed CAF for 11 weeks, and during the last 3 weeks, animals were orally administered MIX or vehicle. Lipid tolerance tests were performed before and after MIX administration. At the end of the experimental period, serum and inguinal white adipose tissue (iWAT) metabolism were analyzed by metabolomics and biochemical approaches. The metabolite signature of serum and iWAT significantly changed after 3 weeks of MIX administration, suggesting an improvement in lipid and glucose homeostasis in these animals. In addition, MIX also exhibited significant antihypertensive properties. These results suggest that MIX could be a good candidate to ameliorate the cardiometabolic risk factors related to MetS.

Performance of Black Bengal goat: a 50-year review

Black Bengal goat (BBG) is the most widely recognized legacy goat breed in Bangladesh. The breed is black in color yet likewise earthy, white, or dim colors additionally found. The breed has medium body size with grown-up weight 25-30 kg, little horns, short legs, and tight body structure. The BBG is one of the most compliant, all around adjusted, early maturing, prolific, productive, and tropical disease-resistant goat types of the world that produces incredible quality meat, milk, and skin. The breed is versatile in hot, moist, cruel, climatic conditions and flourishes well on a cacophonous dietary regimen from uncultivable decrepit grounds, residences, riversides, banks, sloping, and hilly territories where crop culture or dairy nourishing is inconceivable. In Bangladesh, the BBG is one of the main red meat-producing small ruminants which shares remarkable local interest during Eid-Ul-Adha, Eid-Ul-Fitr, wedding ceremony, birthday festival, circumcision, memorial programs, and other social celebrations with no social, cultural, and religious limitations. Being little in size, the BBG has been an amazing asset to advance supportable vocations for the negligible, little, and landless ranchers who rely upon free regular grazing lands for raising domesticated animals. Regardless of incredibly exceptional components and features, the production of BBG has not yet been popularized widely since meager consideration has been paid for improving their efficiency. Development of cutting edge hereditary, dietary, and health as well as disease control procedure and utilization of modern management frameworks may procure considerable changes in improving the overall performance of the BBG.

ACE Inhibitory Activity and Molecular Docking of Gac Seed Protein Hydrolysate Purified by HILIC and RP-HPLC

Gac (Momordica cochinchinensis Spreng.) seed proteins (GSPs) hydrolysate was investigated for angiotensin I-converting enzyme (ACE) inhibitory activities. GSPs were hydrolyzed under simulated gastrointestinal digestion using a combination of enzymes, including pepsin, trypsin, and chymotrypsin. The screening of ACE inhibitory peptides from GSPs hydrolysate was performed using two sequential bioassay-guided fractionations, namely hydrophilic interaction liquid chromatography (HILIC) and reversed-phase high-performance liquid chromatography (RP-HPLC). Then, the peptides in the fraction with the highest ACE inhibitory activity were identified by LC-MS/MS. The flow-through (FT) fraction showed the most potent ACE inhibitory activity when HILIC fractionation was performed. This fraction was further separated using RP-HPLC, and the result indicated that fraction 8 (RP-F8) showed the highest ACE inhibitory activity. In the HILIC-FT/RP-F8 fraction, 14 peptides were identified using LC-MS/MS analysis coupled with de novo sequencing. These amino acid chains had not been recorded previously and their ACE inhibitory activities were analyzed in silico using the BIOPEP database. One fragment with the amino acid sequence of ALVY showed a significant ACE inhibitory activity (7.03 ± 0.09 µM). The Lineweaver-Burk plot indicated that ALVY is a competitive inhibitor. The inhibition mechanism of ALVY against ACE was further rationalized through the molecular docking simulation, which revealed that the ACE inhibitory activities of ALVY is due to interaction with the S1 (Ala354, Tyr523) and the S2 (His353, His513) pockets of ACE. Bibliographic survey allowed the identification of similarities between peptides reported as in gac fruit and other proteins. These results suggest that gac seed proteins hydrolysate can be used as a potential nutraceutical with inhibitory activity against ACE.

Investigation of angiotensin-I-converting enzyme (ACE) inhibitory tri-peptides: a combination of 3D-QSAR and molecular docking simulations

Angiotensin-I-converting enzyme (ACE) is a key enzyme in the regulation of peripheral blood pressure and electrolyte homeostasis. Therefore, ACE is considered as a promising target for treatment of hypertension. In the present work, in order to investigate the binding interactions between ACE and tri-peptides, three-dimensional quantitative structure-activity relationship (3D-QSAR) models using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) methods were developed. Three different alignment methods (template ligand-based, docking-based, and common scaffold-based) were employed to construct reliable 3D-QSAR models. Statistical parameters derived from the QSAR models indicated that the template ligand-based CoMFA (R cv 2 = 0.761, R pred 2 = 0.6257) and CoMSIA (R cv 2 = 0.757, R pred 2 = 0.6969) models were better than the other alignment-based models. In addition, molecular docking studies were carried out to predict the binding modes of the peptides to ACE. The peptide-enzyme interactions were consistent with the derived 3D contour maps. Overall, the insights gained from this study would offer theoretical references for understanding the mechanism of action of tri-peptides when binding to ACE and aid in the design of more potent tri-peptides.

Isolation, Evaluation, and Identification of Angiotensin I-Converting Enzyme Inhibitory Peptides from Game Meat

Game meat has been underutilized, while it offers the potential to diversify not only the human diet but also increase food production and the nutritional value of meat products. This study aimed to determine the angiotensin I-converting enzyme (ACE) inhibitory activities of the digested game meats (venison and boar meat) compared with those of livestock meats (beef and pork). Through the sodium dodecyl sulfate polyacrylamide gel electrophoresis and size chromatography results, we found that the digested products from each meat had different molecular weights. The ACE inhibitory ratio in all tested samples had gradually increased following by the enzyme treatments. ACE inhibitory ratios and the half maximal inhibitory concentration values indicated that digested venison was the most potent inhibitor of ACE activity, followed by the digested boar meat. The level of anserine in digested venison was higher than that in the other meats, but the carnosine level was lower. Through fractionations and liquid chromatography-tandem mass spectrometry analysis, five ACE inhibitory peptides were identified from the digested venison. Of these peptides, Isoleucine-Lysine- Glutamic Acid-Valine-Threonine-Glutamic Acid-Arginine (IKEVTER) demonstrated the highest ACE inhibitory activity. Therefore, the game meat is food that is believed potentially to offer high bioactivities, particularly antihypertensive forces.

Implication of Opioid Receptors in the Antihypertensive Effect of a Novel Chicken Foot-Derived Peptide

The peptide AVFQHNCQE demonstrated to produce nitric oxide-mediated antihypertensive effect. This study investigates the bioavailability and the opioid-like activity of this peptide after its oral administration. For this purpose, in silico and in vitro approaches were used to study the peptide susceptibility to GI digestion. In addition, AVFQHNCQE absorption was studied both in vitro by using Caco-2 cell monolayers and in vivo evaluating peptide presence in plasma from Wistar rats by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) and by ultra-high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS). Both in vivo and in vitro experiments demonstrated that peptide AVFQHNCQE was not absorbed. Thus, the potential involvement of opioid receptors in the BP-lowering effect of AVFQHNCQE was studied in the presence of opioid receptors-antagonist Naloxone. No changes in blood pressure were recorded in rats administered Naloxone, demonstrating that AVFQHNCQE antihypertensive effect is mediated through its interaction with opioid receptors. AVFQHNCQE opioid-like activity would clarify the antihypertensive properties of AVFQHNCQE despite its lack of absorption.

mAHTPred: a sequence-based meta-predictor for improving the prediction of anti-hypertensive peptides using effective feature representation

MOTIVATION

Cardiovascular disease is the primary cause of death globally accounting for approximately 17.7 million deaths per year. One of the stakes linked with cardiovascular diseases and other complications is hypertension. Naturally derived bioactive peptides with antihypertensive activities serve as promising alternatives to pharmaceutical drugs. So far, there is no comprehensive analysis, assessment of diverse features and implementation of various machine-learning (ML) algorithms applied for antihypertensive peptide (AHTP) model construction.

RESULTS

In this study, we utilized six different ML algorithms, namely, Adaboost, extremely randomized tree (ERT), gradient boosting (GB), k-nearest neighbor, random forest (RF) and support vector machine (SVM) using 51 feature descriptors derived from eight different feature encodings for the prediction of AHTPs. While ERT-based trained models performed consistently better than other algorithms regardless of various feature descriptors, we treated them as baseline predictors, whose predicted probability of AHTPs was further used as input features separately for four different ML-algorithms (ERT, GB, RF and SVM) and developed their corresponding meta-predictors using a two-step feature selection protocol. Subsequently, the integration of four meta-predictors through an ensemble learning approach improved the balanced prediction performance and model robustness on the independent dataset. Upon comparison with existing methods, mAHTPred showed superior performance with an overall improvement of approximately 6-7% in both benchmarking and independent datasets.

AVAILABILITY AND IMPLEMENTATION

The user-friendly online prediction tool, mAHTPred is freely accessible at http://thegleelab.org/mAHTPred.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Bioactive Peptides from Walnut Residue Protein

Walnut residue is a kind of high-quality plant protein resource. The bioactive peptide prepared from walnut residue has excellent health care functions such as antioxidation and antihypertensive activity, but at present, walnut residue is often regarded as waste or low value feed, fertilizer and other materials. The uneconomical use of walnut residue has hindered the development of the walnut industry to some extent. Effective utilization of walnut residue protein to develop bioactive peptides and other products is of great significance to realize the comprehensive utilization of walnut residue, improve the added value of by-products, and change the current low utilization rate of walnut residue. In this paper, the preparation, purification and structure identification of walnut protein bioactive peptides are reviewed, and different functional walnut active peptides (WBPs) are introduced. The potential effects of these bioactivities on human health and their different uses in food, medicine and other industries are discussed. The purpose is to provide reference information for the effective utilization of walnut residue resources and the development of walnut industry.

In Silico identification of angiotensin-converting enzyme inhibitory peptides from MRJP1

Hypertension is considered as one of the most common diseases that affect human beings (both male and female) due to its high prevalence and also extending widely to both industrialize and developing countries. Angiotensin-converting enzyme (ACE) has a significant role in the regulation of blood pressure and ACE inhibition with inhibitory peptides is considered as a major target to prevent hypertension. In the current study, a blood pressure regulating honey protein (MRJP1) was examined to identify the ACE inhibitory peptides. The 3D structure of MRJP1 was predicted by utilizing the threading approach and further optimized by performing molecular dynamics simulation for 30 nanoseconds (ns) to improve the quality factor up to 92.43%. Root mean square deviation and root mean square fluctuations were calculated to evaluate the structural features and observed the fluctuations in the timescale of 30 ns. AHTpin server based on scoring vector machine of regression models, proteolysis and structural characterization approaches were implemented to identify the potential inhibitory peptides. The anti-hypertensive peptides were scrutinized based on the QSAR models of anti-hypertensive activity and the molecular docking analyses were performed to explore the binding affinities and potential interacting residues. The peptide "EALPHVPIFDR" showed the strong binding affinity and higher anti-hypertensive activity along with the global energy of -58.29 and docking score of 9590. The aromatic amino acids especially Tyr was observed as the key residue to design the dietary peptides and drugs like ACE inhibitors.

Nitric Oxide Synthesis Inhibition and Anti-Inflammatory Effect of Polypeptide Isolated from Chicken Feather Meal in Lipopolysaccharide-Stimulated RAW 264.7 Macrophages

Nitric oxide (NO) plays a key role in the pathogenesis of inflammation and has been implicated in endotoxin-induced tissue injury. Chicken feather meal is a rich source of amino acids that may serve as a peptide hydrolysate to inhibit NO activity. Anti-inflammatory hydrolysates of chicken feather meal were prepared and fractionated into five samples based on molecular mass. The smallest fraction (<0.65 kDa) exhibited the highest NO inhibitory activity without cytotoxicity towards macrophage RAW 264.7 cells. Further subfractions were sufficient to obtain amino acid sequences by Q-TOF LC-MS/MS ESI analysis. Of these, the SNPSVAGVR (885.97 Da) peptide and its corresponding pure synthetic peptide have inhibitory activity against NO production by RAW 264.7 cells (IC₅₀=(55.2±0.2) mM) without cytotoxicity. Reverse transcriptase polymerase chain reaction (RT-PCR) and quantitative real-time RT-PCR results revealed that the peptide of the obtained fraction reduced transcript expression levels of the pro-inflammatory cytokines iNOS, TNF-α, COX-2 and IL-6 in lipopolysaccharide-stimulated RAW 264.7 cells. These results suggest that the peptides derived from the chicken feather meal protein could potentially be used as a promising ingredient in functional foods or nutraceuticals against inflammatory diseases.

Isolation and Characterization of Three Antihypertension Peptides from the Mycelia of Ganoderma Lucidum (Agaricomycetes)

Ganoderma lucidum (G. lucidum) has been widely used in Asia to treat hypertension, but the active substances responsible for its antihypertensive effects remain unclear. Using the well-established angiotensin I-converting enzyme (ACE) as a target, we identified three ACE inhibitory peptides (ACEIPs), Gln-Leu-Val-Pro (QLVP), Gln-Asp-Val-Leu (QDVL), and Gln-Leu-Asp-Leu (QLDL), which account for the antihypertensive activity of G. lucidum. Notably, QLVP worked in a mixed-type manner against ACE with an IC₅₀ value of 127.9 μmol/L. Molecular dynamics simulation suggested that the potent charge energy of QLVP, which interacted with Gln242 and Lys472 of ACE via a hydrogen bond and a salt bridge, potentially contributed to ACE inhibitory activity. Moreover, QLVP markedly activated angiotensin I-mediated phosphorylation of endothelial nitric oxide synthase in human umbilical vein endothelial cells and partly reduced mRNA and protein expression of the vasoconstrictor factor endothelin-1. This is the first report of the antihypertensive activity of small ACEIPs originating from G. lucidum mycelia, paving the way for the possible application of these peptides as potent drug candidates for treating hypertension.

Bioactivities of enzymatic protein hydrolysates derived from Chlorella sorokiniana

Chlorella sorokiniana protein isolates were enzymatically hydrolyzed using pepsin, bromelain, and thermolysin, with their molecular characteristics and bioactivities determined. Thermolysin hydrolysates exhibited the highest degree of hydrolysis (18.08% ± 1.13%). The sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) results showed that peptides with molecular weights <10 kDa were found in the hydrolysates compared to the protein isolates. Bioactivity assays revealed that pepsin peptide fraction <5 kDa showed the highest angiotensin-converting enzyme (ACE)-inhibitory (34.29% ± 3.45%) and DPPH radical scavenging activities (48.86% ± 1.95%), while pepsin peptide fraction <10 kDa demonstrated the highest reducing power with 0.2101% ± 0.02% absorbance. Moreover, antibacterial assessment revealed that pepsin hydrolysate and peptide fractions displayed inhibition to the test microorganisms. Overall, the present findings suggest that C. sorokiniana protein hydrolysates can be valuable bio-ingredients with pharmaceutical and nutraceutical application potentials.

Novel Antihypertensive Peptides Derived from Chicken Foot Proteins

SCOPE

Chicken foot proteins have recently been demonstrated by the group to be a great source of hydrolysates with antihypertensive properties. The aim of this study was to isolate and identify angiotensin I-converting enzyme inhibitory (ACEI) peptides from chicken foot hydrolysate Hpp11 and to test their antihypertensive properties.

METHODS AND RESULTS

Peptides are separated into fractions according to their molecular size and hydrophobicity by ultrafiltration and RP-HPLC, respectively. Subsequent peptide identification in the two fractions that present the highest ACEI activities is carried out by HPLC-MS. Ten of the identified peptides are synthesized and five of them show ACEI (IC50 ) values lower than 100 µm. The antihypertensive effects of these ACEI peptides after oral administration is evaluated in spontaneously hypertensive rats. The peptides AVFQHNCQE and QVGPLIGRYCG exhibit antihypertensive activity when administered at an oral dose of 10 mg kg-1 body weight. The maximal decrease in systolic blood pressure is recorded 6 h after their administration (-25.07 ± 4.21 and -10.94 ± 1.96 mmHg, respectively).

CONCLUSION

These results suggest that AVFQHNCQE and QVGPLIGRYCG could be used as functional ingredients with antihypertensive effects, although it would be necessary to perform bioavailability and clinical studies to demonstrate their efficiency in humans.

Protein components of water extracts from fruiting bodies of the reishi mushroom Ganoderma lucidum contribute to the production of functional molecules

BACKGROUND

Mushrooms have been widely considered as health foods as their extracts have anti-hypertensive and anti-tumor activities. After a thorough literature survey, we hypothesized that enzymes in mushroom extracts play an important role in synthesizing functional molecules. Therefore, in this study, proteins extracted from reishi mushroom (Ganoderma lucidum), which is used in oriental medicine, were identified by the proteomic approach, and appropriate extraction methods for improving angiotensin-converting enzyme (ACE) inhibitory activities were investigated.

RESULTS

Various glycoside hydrolases (GHs), such as β-N-acetylhexosaminidase (GH family 20), α-1,2-mannosidase (GH family 47), endo-β-1,3-glucanase (GH family 128), and β-1,3-glucanase (GH152), that degrade glycans in the fruiting body were identified. The residual glucanase activities generated β-oligosaccharides. Additionally, the glutamic acid protease of the peptidase G1 family was determined as the major protein in the extract, and the residual peptidase activity of the extracts was found to improve ACE inhibitory activities. Finally, it was observed that extraction at 50 °C is suitable for yielding functional molecules with high ACE inhibitory activities.

CONCLUSION

Water extraction is generally believed to extract only functional macromolecules that exist in mushroom fruiting bodies. This study proposed a new concept that describes how functional molecules are produced by enzymes, including proteases and GHs, during extraction. © 2018 Society of Chemical Industry.