Preparation and antagonistic effect of ACE inhibitory peptide from cashew

Plant Protein-Derived Active Peptides: A Comprehensive Review

Active peptides are a class of physiologically active protein fragments, which can be prepared from different sources. In the past few decades, the production of peptides with various effects from different plant proteins continues to receive academic attention. With advances in extraction, purification, and characterization techniques, plant protein-derived active peptides continue to be discovered. They have been proven to have various functional activities such as antioxidant, antihypertensive, immunomodulatory, antimicrobial, anti-inflammatory, antidiabetic, antithrombotic, and so on. In this review, we searched Web of Science and China National Knowledge Infrastructure for relevant articles published in recent years. There are 184 articles included in this manuscript. The current status of plant protein-derived active peptides is systematically introduced, including their sources, preparation, purification and identification methods, physiological activities, and applications in the food industry. Special emphasis has been placed on the problems of active peptide exploration and the future trend. Based on these, it is expected to provide theoretical reference for the further exploitation of plant protein-derived active peptides, and promote the healthy and rapid development of active peptide industry.

Identification and Anti-Hyperuricemic Activity of Xanthine Oxidase Inhibitory Peptides from Pacific White Shrimp and Swimming Crab Based on Molecular Docking Screening

The xanthine oxidase (XO) inhibitory peptides from pacific white shrimp or swimming crab were identified by molecular docking, and the anti-hyperuricemic activity of the peptides was confirmed in hyperuricemic cells. In our study, 17 novel XO inhibitory peptides were purified from pacific white shrimp or swimming crab, and Ala-Glu-Ala-Gln-Met-Trp-Arg (AEAQMWR, 891.01 Da, IC₅₀ = 8.85 ± 0.05 mM) exhibited the greatest XO inhibitory activity in vitro. Molecular docking results indicated that attractive charge, salt bridge, and hydrogen bond showed a crucial effect on the interactions of XO inhibitory peptides with the pivotal residues of Arg880, Glu802, and Glu1261. In addition, XO inhibitory peptides alleviated hyperuricemia by inhibiting inflammation and preventing increased uric acid transporter expression levels in hyperuricemia cells. Overall, these results further confirmed that screening of XO inhibitory peptides rapidly via molecular docking was feasible.

Research on ACEI of Low-Molecular-Weight Peptides from Hirudo Nipponia Whitman

The renin-angiotensin system (RAS) is the primary pathway for regulating blood pressure in the body, and angiotensin-converting enzymes (ACEs) play a crucial role in it. Hirudo nipponia is an invertebrate that contains a variety of active peptides; however, there are no studies on the ACE inhibitory activity of hirudo. In the present study, our aim was to identify the active peptides in hirudo based on active peptide database analysis, unexpectedly filling the gap in hirudo ACE inhibitory activity research. Prep-HPLC was used to separate the part below 3 kD from hirudo. The peptide composition of the isolates was obtained based on Orbitrap LC-MS. The activity of each group of peptides was predicted by the database and the activity was determined by bioassay. Peptides with validation activity were screened through the database. In total, 337 peptides and 18 peptides matching the NCBI leech protein database were identified. All four fractions showed ACE inhibitory activity, and the IC50 was 0.8266, 0.2708, 0.4432, and 0.1764 mg/mL, respectively. Six screened peptides showed good affinity for ACE. This work reveals for the first time that low-molecular-weight peptides from H. nipponia have ACE inhibitory activity, which can provide a new explanation for leech treatment of hypertension.

Blood pressure and sugar regulating potentials of Anarcadium occidentale nut globulin and albumin hydrolysates

Several novel functional peptides have been successfully extracted from plant storage proteins. This study investigated the degree of hydrolysis, peptide yield, amino acid constituents, angiotensin converting enzyme (ACE), alpha amylase inhibitory and in vitro antioxidant activities of cashew (Anarcardium occidentale) nut proteins (CNP) hydrolysates (CNPHs). Cashew nut proteins (albumin and globulin) were hydrolysed using pancreatin, Alcalase and trypsin. The peptide yield and degree of hydrolysis (DH) of CNP by pancreatin (75.69 ± 0.84%; 37.39 ± 0.31) was significantly higher than those by Alcalase (61.67 ± 0.55%; 23.87 ± 0.23) and trypsin (43.33 ± 0.45%; 11 ± 0.15). The inhibition of ACE by albumin and globulin hydrolysates was concentration dependent. At 1.2 mg/mL, ACE-inhibitory activity of pancreatic cashew nut globulin (CNGH) hydrolysate (51.65 ± 1.2%) was significantly higher than those of Alcalase (34.603 ± 0.65%) and tryptic (29.92 ± 0.73%) CNGHs. Cashew nut albumin hydrolysate (CNAH) demonstrated concentration-dependent alpha-amylase inhibition (IC50 0.17 ± 0.02-0.41 ± 0.021 mg/mL). The order of inhibition was tryptic > Alcalase > pancreatic CNAHs. The pancreatic hydrolysates of both albumin and globulin fractions displayed the highest DPPH antioxidant activity, while pancreatic CNAH was the most potent superoxide anion scavenger. These findings therefore posit that cashew nut globulin and albumin hydrolysates are laden with useful bioactive peptides that may be further explored for regulation of blood pressure and sugar in hypertensive and diabetic in vivo models.

Identification and Antihypertension Study of Novel Angiotensin I-Converting Enzyme Inhibitory Peptides from the Skirt of Chlamys farreri Fermented with Bacillus natto

The aim of this study was to isolate the angiotensin I-converting enzyme (ACE) inhibitory peptides from the skirt of Chlamys farreri fermented with Bacillus natto and to explore the antihypertension effect through in vivo studies. ACE inhibitory peptides were purified from the fermentation mixture by ultrafiltration, gel filtration chromatography, and reversed-phase high-performance liquid chromatography sequentially. The amino acids' sequence of the five novel ACE inhibitory peptides were identified by liquid chromatography-tandem mass spectrometry. Animal experiments demonstrated that the novel ACE inhibitory peptides significantly reduced the blood pressure in spontaneously hypertensive rats after a single or long-time treatment. Potential mechanisms were explored, and the results indicated that the novel peptides could regulate the renal renin-angiotensin system, improve vascular remodeling, inhibit myocardial fibrosis, and rebalance the gut microbial dysbiosis. Our results suggest that the fermentation products of the Chlamys farreri skirt by B. natto are potential sources of active peptides processing antihypertension activities.