Anti-Hypertensive Activity of Novel Peptides Identified from Olive Flounder (Paralichthys olivaceus) Surimi

Antihypertensive Effect of Milk Fermented by Lactiplantibacillus plantarum K79 on Spontaneously Hypertensive Rats

The aim of this study is to investigate whether milk fermented by Lactiplantibacillus plantarum K79, which exhibits angiotensin-converting enzyme inhibitory activity, has an effect on lowering the blood pressure of hypertensive rats and to investigate biomarker changes in their blood. Experimental group: normal group (NG, Wistar-Kyoto rats): distilled water, control group [NCG, spontaneously hypertensive rats (SHR)]: distilled water, high treatment group (HTG, SHR): 500 mg/kg/day, medium treatment group (SHR): 335 mg/kg/day, low treatment group (SHR): 170 mg/kg/day, positive control group (PCG, SHR): Enalapril, 10 mg/kg/day. The experimental animals used in this study were divided into groups composed of 8 animals. In terms of weight change, a significant difference was observed between the NG and the SHR group, but there was no significant difference between the SHR group. After 8 wk of feeding, blood pressure was lowered more significantly in the HTG (209.9±13.3 mmHg) than in the NCG (230.8±7.3 mmHg). The treatment group has an effect of lowering blood pressure by significantly suppressing blood pressure-related biomarker protein expression than NG. The results obtained can be used as an antihypertensive material in a variety of food raw materials.

Advancements of fish-derived peptides for mucormycosis: a novel strategy to treat diabetic compilation

Mucormycosis, an extremely fatal fungal infection, is a major hurdle in the treatment of diabetes consequences. The increasing prevalence and restricted treatment choices urge the investigation of novel therapeutic techniques. Because of their effective antimicrobial characteristics and varied modes of action, fish-derived peptides have lately emerged as viable options in the fight against mucormycosis. This review examines the potential further application of fish-derived peptides in diagnosing and managing mucormycosis in relation to diabetic complications. First, we examine the pathophysiology of mucormycosis and the difficulties in treating it in diabetics. We emphasize the critical need for alternative therapeutic methods for tackling the limitations of currently available antifungal medicines. The possibility of fish-derived peptides as an innovative approach to combat mucormycosis is then investigated. These peptides, derived from several fish species, provide wide antimicrobial properties against a variety of diseases. They also have distinct modes of action, such as rupture of cell membranes, suppression of development, and modification of the host immunological response. Furthermore, we investigate the problems and prospects connected with the clinical application of fish-derived peptides. Ultimately, future advances in fish-derived peptides, offer interesting avenues for the management of mucormycosis in the context of diabetic comorbidities. More research and clinical trials are needed to properly investigate these peptide's therapeutic potential and pave the way for their adoption into future antifungal therapies.

The Nutritional and Functional Properties of Protein Isolates from Defatted Chia Flour Using Different Extraction pH

This study aims to determine the effects of various alkaline pHs on the nutritional and functional properties of protein isolated from defatted chia flour (DCF). The DCF isolated using alkali extraction method at pH 8.5, 10.0, and 12.0 were coded as CPI-8.5, CPI-10.0, and CPI-12.0, respectively. The highest extraction yield and protein recovery yield was demonstrated by CPI-12.0 (19.10 and 59.63%, respectively), with a total protein content of 74.53%, and glutelin showed the highest portion (79.95%). The CPI-12.0 also demonstrated the most elevated essential (36.87%), hydrophobic (33.81%), and aromatic (15.54%) amino acid content among other samples. The DCF exhibited the highest water (23.90 gg-1) and oil (8.23 gg-1) absorption capacity, whereas the CPI-8.5 showed the highest protein solubility (72.31%) at pH 11. DCF demonstrated the highest emulsifying capacity at pH 11 (82.13%), but the highest stability was shown at pH 5 (82.05%). Furthermore, CPI-12.0 at pH 11 shows the highest foaming capacity (83.16%) and stability (83.10%). Despite that, the CPI-10.0 manifested the highest antioxidant capacity (DPPH: 42.48%; ABTS: 66.23%; FRAP: 0.19), as well as ACE-I (35.67%). Overall, the extraction pH had significant effects in producing chia protein isolates (CPI) with improved nutritional and functional qualities.

Purification, Identification, and Inhibitory Mechanisms of a Novel ACE Inhibitory Peptide from Torreya grandis

Torreya grandis meal has a high protein content and an appropriate amino acid ratio, making it an excellent protein source for producing ACE inhibitory peptides. To promote its application in food, medicine, and other fields, an alkaline protease hydrolysate of Torreya grandis was used in this study to isolate and identify a novel angiotensin-converting enzyme inhibitory peptide, VNDYLNW (VW-7), using ultrafiltration, gel chromatography purification, LC-MS/MS, and in silico prediction. The results show that the IC₅₀ value of VW-7 was 205.98 µM. The Lineweaver-Burk plot showed that VW-7 had a mixed-type inhibitory effect on ACE. Meanwhile, according to the results of molecular docking, VW-7 demonstrated a strong affinity for ACE (binding energy -10 kcal/mol). VW-7 was bound to ACE through multiple binding sites. In addition, VW-7 could remain active during gastrointestinal digestion in vitro. Nitric oxide (NO) generation in human endothelial cells could rise after receiving a pretreatment with VW-7. These results indicated that Torreya grandis meal protein can be developed into products with antihypertensive function, and VW-7 has broad application prospects in the field of antihypertensive.

Selenized Chickpea Sprouts Hydrolysates as a Potential Anti-Aging Ingredient

Skin aging represents a health and aesthetic problem that could result in infections and skin diseases. Bioactive peptides can potentially be used in skin aging regulation. Chickpea (Cicer arietinum L.) selenoproteins were obtained from germination with 2 mg Na₂SeO₃/100 g of seeds for 2 days. Alcalase, pepsin, and trypsin were used as hydrolyzers, and a membrane < 10 kDa was used to fractionate the hydrolysate. Se content, antioxidant capacity, elastase and collagen inhibition, functional stability, and preventative capacity were analyzed. Significant increases in Se content were found in germinated chickpea flour and protein related to the control. An increase of 38% in protein was observed in the selenized flour related to the control. A band (600-550 cm^-1) observed in the selenized hydrolysates suggested the insertion of Se into the protein. Hydrolysates from pepsin and trypsin had the highest antioxidant potential. Se enhanced the stability of total protein and protein hydrolysates through time and increased their antioxidant capacity. Hydrolysates > 10 kDa had higher elastase and collagenase inhibition than the total protein and hydrolysates < 10 kDa. Protein hydrolysates < 10 kDa 6 h before UVA radiation had the highest inhibition of collagen degradation. Selenized protein hydrolysates showed promising antioxidant effects that could be related to skin anti-aging effects.

Abalone Viscera Fermented with Aspergillus oryzae 001 Prevents Pressure Elevation by Inhibiting Angiotensin Converting Enzyme

Abalone viscera, which accounts for more than 20% of the total weight of abalone, is generally regarded as waste in the food industry, and effective methods are required to utilize it productively. In this study, the viscera were fermented with Aspergillus oryzae 001 to add functionality. Fermented abalone viscera exhibited increased angiotensin I-converting enzyme (ACE) inhibitory activity and enhanced inhibition of blood pressure elevation in spontaneously hypertensive rats (SHRs). Abalone viscera administration had no significant effect on body weight, food intake, liver and kidney weights, or serum components in SHRs. ACE inhibitors specific to fermented abalone viscera were identified through extraction, fractionation, purification, and analysis. The identified substance was L-m-tyrosine, which non-competitively inhibited ACE and, in a single oral administration, significantly reduced blood pressure in SHRs compared to that in the control. This study identified that abalone viscera fermented by A. oryzae 001 has an inhibitory effect on blood pressure elevation, suggesting its potential use as a functional food. In addition, L-m-tyrosine, a unique substance in fermented abalone viscera, was isolated for the first time as a single ACE-inhibitory amino acid.

Anti-inflammatory effect of fucoidan isolated from fermented Sargassum fusiforme in in vitro and in vivo models

Fucoidans possess potent anti-inflammatory effects. In the present study, the anti-inflammatory effect of the fucoidan (SFF-PS-F5) isolated from fermented Sargassum fusiforme was evaluated in vitro in RAW 264.7 macrophages and in vivo in zebrafish. The in vitro test results demonstrate that SFF-PS-F5 effectively inhibited nitric oxide (NO) production induced by lipopolysaccharides (LPS) in RAW 264.7 cells. SFF-PS-F5 effectively and concentration-dependently improved the viability of LPS-stimulated RAW 264.7 cells, and reduced the level of prostaglandin E2, interleukin-1 beta, tumor necrosis factor-alpha, and interleukin-6. Further results display that these effects were actioned by suppressing the expression of inducible nitric oxide synthase and cyclooxygenase-2 via regulating the nuclear factor kappa-B signaling pathway. The in vivo test results indicate that SFF-PS-F5 remarkably reduced reactive oxygen species, cell death, and NO levels in LPS-treated zebrafish. These results indicate that SFF-PS-F5 could inhibit both in vitro and in vivo inflammatory responses and suggest it is a functional ingredient in the functional food and cosmetic industries.

Recent findings on the cellular and molecular mechanisms of action of novel food-derived antihypertensive peptides

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Hypertension has remained a silent-killer.

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Novel peptides recently isolated from food proteins.

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Molecular mechanism of blood pressure-lowering: renin and ACE-inhibition, and beyond.

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Proposed molecular mechanisms for future research.

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Novel peptides are excellent candidates for nutraceutical development.

Hypertension impacts negatively on the quality of life of sufferers, and complications associated with uncontrolled hypertension are life-threatening. Hence, many research efforts are exploring the antihypertensive properties of bioactive peptides derived from food proteins using in vitro ACE-inhibitory assay, experimentally-induced and spontaneous hypertensive rats, normotensive and hypertensive human models. In this study, the cellular and molecular mechanisms of blood pressure-lowering properties of novel peptides reported in recent studies (2015-July 30, 2021) were discussed. In addition to common mechanisms such as the inhibition of angiotensin I-converting enzyme (ACE) and renin activities, recently recognized mechanisms through which bioactive peptides exert their antihypertensive properties including the induction of vasodilation via upregulation of cyclo-oxygenase (COX) and prostaglandin receptor and endothelial nitric oxide synthase expression and L-type Ca²⁺ channel blockade were presented. Similarly, emerging mechanisms of blood pressure-lowering by bioactive peptides such as modulation of inflammation (TNF-α, and other cytokines signaling), oxidative stress (Keap-1/Nrf2/ARE/HO-1 and related signaling pathways), PPAR-γ/caspase3/MAPK signaling pathways and inhibition of lipid accumulation were discussed. The review also highlighted factors that influence the antihypertensive properties of peptides such as method of hydrolysis (type and number of enzymes, and chemical used for hydrolysis, and microbial fermentation), and amino acid sequence and chain length of peptides.

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.

Antioxidant activity of olive flounder (Paralichthya olivaceus) surimi digest in in vitro and in vivo

Surimi is refined myofibrillar proteins of fish, which are materials of processed seafood products. However, the health-related outcomes associated with surimi consumption need further investigation. Given the high valued impact of surimi in the functional food industry, the study aims to evaluate its digest with regard to antioxidant potential to understand health benefits raised by surimi consumption. Paralichthys olivaceus surimi digest (POSD) showed a significant DPPH and alkyl radical scavenging activity and protective effects against 2,20-azobis (2-methylpropionamidine) dihydrochloride (AAPH)-induced oxidative stressed Vero cells with a significant increasing cell viability and decreasing apoptosis. It also dramatically suppressed the production of reactive oxygen species and lipid peroxidation as well as prevented cell death and down-regulated pro-apoptotic genes at the mRNA levels in AAPH-stimulated zebrafish. This study reports the protective effects against oxidative stressed cells and zebrafish by a strong antioxidant activity of POSD. Therefore, surimi consumption could be a potential benefit in the prevention of oxidative stress-related diseases.

An Updated Review of Bioactive Peptides from Mushrooms in a Well-Defined Molecular Weight Range

Here, we report the current status of the bioactive peptides isolated and characterized from mushrooms during the last 20 years, considering ‘peptide’ a succession from to 2 to 100 amino acid residues. According to this accepted biochemical definition, we adopt ~10 kDa as the upper limit of molecular weight for a peptide. In light of this, a careful revision of data reported in the literature was carried out. The search revealed that in the works describing the characterization of bioactive peptides from mushrooms, not all the peptides have been correctly classified according to their molecular weight, considering that some fungal proteins (>10 kDa MW) have been improperly classified as ‘peptides’. Moreover, the biological action of each of these peptides, the principles of their isolation as well as the source/mushroom species were summarized. Finally, this review highlighted that these peptides possess antihypertensive, antifungal, antibiotic and antimicrobial, anticancer, antiviral, antioxidant and ACE inhibitory properties.