The antihypertensive effect and mechanisms of bioactive peptides from Ruditapes philippinarum fermented with Bacillus natto in spontaneously hypertensive rats

Marine-Derived Peptides with Anti-Hypertensive Properties: Prospects for Pharmaceuticals, Supplements, and Functional Food

Hypertension, a major health concern linked to heart disease and premature mortality, has prompted a search for alternative treatments due to side effects of existing medications. Sustainable harvesting of low-trophic marine organisms not only enhances food security but also provides a variety of bioactive molecules, including peptides. Despite comprising only a fraction of active natural compounds, peptides are ideal for drug development due to their size, stability, and resistance to degradation. Our review evaluates the anti-hypertensive properties of peptides and proteins derived from selected marine invertebrate phyla, examining the various methodologies used and their application in pharmaceuticals, supplements, and functional food. A considerable body of research exists on the anti-hypertensive effects of certain marine invertebrates, yet many species remain unexamined. The array of assessments methods, particularly for ACE inhibition, complicates the comparison of results. The dominance of in vitro and animal in vivo studies indicates a need for more clinical research in order to transition peptides into pharmaceuticals. Our findings lay the groundwork for further exploration of these promising marine invertebrates, emphasizing the need to balance scientific discovery and marine conservation for sustainable resource use.

Angiotensin-converting enzyme inhibitory peptide IVGFPAYGH protects against liver injury in mice fed a high‑sodium diet by inhibiting the RAS and remodeling gut microbial communities

Consuming a high‑sodium diet carries serious health risks and significantly influences the activation state of the renin-angiotensin system (RAS). This study evaluates the protective effect of angiotensin-converting enzyme (ACE) inhibitory peptide IVGFPAYGH on a high‑sodium diet-induced liver injury. IVGFPAYGH supplementation increased the activities of liver antioxidase and decreased the levels of liver inflammatory factor in mice fed a high‑sodium diet (8 % NaCl). IVGFPAYGH supplementation also reduced liver fatty acid synthesis and promoted fatty acid oxidation, increased the expression of low-density lipoprotein receptor, and improved liver dyslipidemia. Furthermore, IVGFPAYGH supplementation inhibited the activation of the liver RAS via inhibiting ACE activity and reducing angiotensin II levels in mice fed a high‑sodium diet. Moreover, IVGFPAYGH supplementation could alter the gut microbiota composition toward a normal gut microbiota composition and increase the abundance of the Lactobacillus genus. IVGFPAYGH supplementation also increased the expression levels of small intestinal tight junction protein and cecum short-chain fatty acids. Thus, IVGFPAYGH supplementation may maintain intestinal homeostasis and improve high‑sodium diet-induced liver injury by altering the gut microbiota composition and inhibiting the RAS. IVGFPAYGH is a promising functional ingredient for protecting liver damage caused by a high‑sodium diet.

Immune Enhancement of Clam Peptides on Immunosuppressed Mice Induced by Hydrocortisone

Clam peptides, marine-derived biological peptides, have been broadly investigated and applied as health foods, among which immunomodulation is one of their biological activities that cannot be ignored in vivo. In this study, we concentrated on exploring the effects of Ruditapes philippinarum peptides (RPPs) on immunomodulation and the balance of intestinal microbiota in hydrocortisone (HC)-induced immunosuppressed mice. The results revealed that RPPs could increase the thymus and spleen indices and number of white blood cells, promote the secretion level of cytokines (IL-2, IL-6, TNF-α, and INF-γ), repair the morphology of the spleen and thymus, and enhance the proliferation of T-lymphocyte subsets in immunosuppressed mice. Moreover, RPPs improved the abundance of beneficial bacteria and preserved the ecological equilibrium of the gut microbiota. In conclusion, RPPs have significant immunomodulatory effects on immunosuppressed mice and may be developed as immunomodulators or immune adjuvants in functional foods and drugs; they are also beneficial to the utilization of the high value of marine shellfish.

A Novel LSTM-Based Machine Learning Model for Predicting the Activity of Food Protein-Derived Antihypertensive Peptides

Food protein-derived antihypertensive peptides are a representative type of bioactive peptides. Several models based on partial least squares regression have been constructed to delineate the relationship between the structure and activity of the peptides. Machine-learning-based models have been applied in broad areas, which also indicates their potential to be incorporated into the field of bioactive peptides. In this study, a long short-term memory (LSTM) algorithm-based deep learning model was constructed, which could predict the IC₅₀ value of the peptide in inhibiting ACE activity. In addition to the test dataset, the model was also validated using randomly synthesized peptides. The LSTM-based model constructed in this study provides an efficient and simplified method for screening antihypertensive peptides from food proteins.

Antihypertensive effects of Pleurospermum lindleyanum aqueous extract in spontaneously hypertensive rats

ETHNOPHARMACOLOGICAL RELEVANCE

Pleurospermum lindleyanum (Lipsky) B. Fedtsch is a perennial herb classified in the Apiaceae family, genus Pleurospermum, chiefly native to the Taxkorgan County, Xinjiang, China. In the Xinjiang Province, it is a well-known ethnic traditional herb, often addressed by its tribal name, Kurumuti. It grows in harsh conditions over 4000 m above sea level, such as the Pamirs plateau. It is rich in flavonoids, coumarins, terpenoids, essential oil, substances that have been widely applied in the prevention and treatment of hypertension, diabetes, coronary heart disease, and cerebral thrombosis by local Tajik residents.

AIMS OF THE STUDY

The present study aimed to evaluate the antihypertensive effects of the Pleurospermum Lindleyanum aqueous extract (PLAE) in spontaneously hypertensive rats (SHRs).

MATERIALS AND METHODS

The Pleurospermum lindleyanum was collected from the Taxkorgan Tajik Autonomous County, Xinjiang, China. The main chemical composition of PLAE was identified using the ultra-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF-MS). SHRs were treated by gavage with PLAE (equivalent to Pleurospermum lindleyanum 5 or 10 g/kg/day) for 6 weeks, using Captopril (10 mg/kg/day) as positive control. The systolic blood pressure (SBP), renal and cardiac morphology, plasma levels of angiotensin-converting enzyme (ACE), aldosterone (ALD), angiotensinⅡ (AngⅡ), superoxide dismutase (SOD), endothelin-1 (ET-1) and nitric oxide (NO) were measured.

RESULTS

A total of 30 compounds were identified in PLAE. PLAE significantly attenuated the SBP of SHRs. The effects began after 3 weeks of administration and then became steady and long-lasting. Its potential mechanisms may be associated with the protective effects on renal and cardiac injury caused by hypertension, the decrease of plasma vasoconstrictors, such as ACE, ALD, AngⅡ, and ET-1 levels, the maintenance of NO/ET balance, the increase in plasma NO levels and SOD activity, thereby reducing oxidative stress.

CONCLUSION

Pleurospermum lindleyanum can be suggested as a novel antihypertensive ethnic traditional herb, which lays the foundation for researching safe and effective antihypertensive herbal medicines.

Recent Advances in In Vitro and In Vivo Studies of Antioxidant, ACE-Inhibitory and Anti-Inflammatory Peptides from Legume Protein Hydrolysates

Consumption of legumes has been shown to enhance health and lower the risk of cardiovascular disease and specific types of cancer. ACE inhibitors, antioxidants, and synthetic anti-inflammatories are widely used today; however, they have several undesirable side effects. Thus, researchers have focused on finding ACE inhibitors, antioxidant, and anti-inflammatory peptides from natural sources, such as legumes. Recently, in vitro and in vivo research has shown the bioactive peptides generated from legume protein hydrolysates, such as antioxidant, anti-hypertensive, anticancer, anti-proliferative, anti-inflammatory, etc., in the context of different disease mitigation. Therefore, this review aims to describe the recent advances in in vitro and in vivo studies of antioxidant, anti-hypertensive and anti-inflammatory peptides isolated from legume-derived protein hydrolysates. The results indicated that antioxidant legumes peptides are characterized by short-chain sequence amino acids and possess anti-hypertensive properties by reducing systolic blood pressure (SBP) in spontaneously hypertensive rats (SHR).

Food Peptides, Gut Microbiota Modulation, and Antihypertensive Effects

The gut microbiota is increasingly important in the overall human health and as such, it is a target in the search of novel strategies for the management of metabolic disorders including blood pressure, and cardiovascular diseases. The link between microbiota and hypertension is complex and this review is intended to provide an overview of the mechanism including the production of postbiotics, mitigation of inflammation, and the integration of food biological molecules within this complex system. The focus is on hydrolyzed food proteins and peptides which are less commonly investigated for prebiotic properties. The analysis of available data showed that food peptides are multifunctional and can prevent gut dysbiosis by positively affecting the production of postbiotics or gut metabolites (short-chain fatty acids, polysaccharides, biogenic amines, bile acids). Peptides and the postbiotics then displayed antihypertensive effects via the renin-angiotensin system, the gut barrier, the endothelium, and reduction in inflammation and oxidative stress. Despite the promising antihypertensive effect of the food peptides via the modulation of the gut, there is a lack of human studies as most of the works have been conducted in animal models.

The Ameliorative Effect and Mechanisms of Ruditapes philippinarum Bioactive Peptides on Obesity and Hyperlipidemia Induced by a High-Fat Diet in Mice

In this study, bioactive peptides (RBPs) from Ruditapes philippinarum were prepared by fermentation with Bacillus natto and the effect and mechanisms of RBPs on obesity and hyperlipidemia were explored in mice. We found that RBPs significantly reduced body weight, adipose tissue weight, accumulation of hepatic lipids, and serum levels of total cholesterol (CHO), triglyceride (TG), and low-density lipoprotein (LDL). Mechanistic studies showed that RBPs up-regulated the hepatic expression of genes related to lipolysis, such as hormone-sensitive lipase (HSL), phosphorylated AMP-activated protein kinase (p-AMPK), and peroxisome proliferator-activated receptors α (PPARα), and down-regulated the expression of peroxisome proliferator-activated receptors γ (PPARγ) which is related to lipid synthesis. In addition, RBPs could attenuate obesity and hyperlipidemia by regulating disordered gut microbiota composition, such as increasing the abundance of microflora related to the synthesis of short chain fatty acids (SCFAs) (Bacteroidetes, Prevotellaceas_UCG_001, norank_f_Muribaculaceae, and Odoribacter) and controlling those related to intestinal inflammation (reduced abundance of Deferribacteres and increased abundance of Alistipes and ASF356) to exert anti-obesity and lipid-lowering activities. Our findings laid the foundation for the development and utilization of RBPs as a functional food to ameliorate obesity and hyperlipidemia.

Preparation and Hepatoprotective Activities of Peptides Derived from Mussels (Mytilus edulis) and Clams (Ruditapes philippinarum)

Low molecular weight (<5 kDa) peptides from mussels (Mytilus edulis) (MPs) and the peptides from clams (Ruditapes philippinarum) (CPs) were prepared through enzymatic hydrolysis by proteases (dispase, pepsin, trypsin, alcalase and papain). Both the MPs and the CPs showed excellent in vitro scavenging ability of free radicals including OH, DPPH and ABTS in the concentration range of 0.625−10.000 mg/mL. By contrast, the MPs hydrolyzed by alcalase (MPs-A) and the CPs hydrolyzed by dispase (CPs-D) had the highest antioxidant activities. Furthermore, MPs-A and CPs-D exhibited protective capabilities against oxidative damage induced by H2O2 in HepG2 cells in the concentration range of 25−800 μg/mL. Meanwhile, compared with the corresponding indicators of the negative control (alcohol-fed) mice, lower contents of hepatic MDA and serums ALT and AST, as well as higher activities of hepatic SOD and GSH-PX were observed in experiment mice treated with MPs-A and CPs-D. The present results clearly indicated that Mytilus edulis and Ruditapes philippinarum are good sources of hepatoprotective peptides.

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.

Recent Progress in Electronic Noses for Fermented Foods and Beverages Applications

Fermented foods and beverages have become a part of daily diets in several societies around the world. Emitted volatile organic compounds play an important role in the determination of the chemical composition and other information of fermented foods and beverages. Electronic nose (E-nose) technologies enable non-destructive measurement and fast analysis, have low operating costs and simplicity, and have been employed for this purpose over the past decades. In this work, a comprehensive review of the recent progress in E-noses is presented according to the end products of the main fermentation types, including alcohol fermentation, lactic acid fermentation, acetic acid fermentation and alkaline fermentation. The benefits, research directions, limitations and challenges of current E-nose systems are investigated and highlighted for fermented foods and beverage applications.

Functional yogurt fermented by two-probiotics regulates blood lipid and weight in a high-fat diet mouse model

We investigated the blood lipid regulation effects and mechanism of a functional Natto yogurt in a high-fat diet-induced hyperlipidemia mouse model. Natto yogurt was characteristically fermented by Bacillus natto and Lactobacillus plantarum with milk-soy dual protein as substrates. After 5 weeks of Natto yogurt consumption, the body weight, fat, and liver weight of mice were significantly improved, while serum levels of TG, TC, LDL, ALT, TBIL, and TBA were reduced. Natto yogurt significantly decreased the area of liver fat infiltration and the number of lipid droplets. In mechanism, we found that Natto yogurt can inhibit fatty acid synthesis and enhance fatty acid catabolism by regulating the expression of PPARα, PPARγ, CD36 and FAS in the liver. Moreover, Natto yogurt increased the ratio of Bacteroidetes to Firmicutes in the intestine. These results provide a possibility for Natto yogurt as a dual protein functional food to prevent and treat hyperlipidemia and obesity. PRACTICAL APPLICATIONS: Traditional-fermented yogurt promotes nutritional absorption and reduces blood pressure and fat, while Bacillus natto and its fermented food have been proved to play a significant role in improving cardiovascular and cerebrovascular diseases and obesity. Therefore, we developed a new dual protein functional yogurt (Natto yogurt) fermented by B. natto and Lactobacillus plantarum with milk and soy as substrates. We found that Natto yogurt could notably regulate blood lipid by inhibiting the synthesis of fatty acids, accelerating the catabolism of fatty acids, reducing liver damage, and increasing the abundance of beneficial intestinal microorganisms. This study suggested that Natto yogurt could improve hyperlipidemia and obesity as a safe, effective, and healthy functional food.

Moutan Cortex polysaccharide ameliorates diabetic kidney disease via modulating gut microbiota dynamically in rats

Growing evidence suggests that polysaccharides from traditional Chinese medicine positively affect diabetic kidney disease (DKD) mainly through modulating gut microbiota. Previously, we demonstrated that supplementation with the polysaccharide from Moutan Cortex (MC-Pa) alleviated DKD in rats. The study intends to investigate the dynamic modulation of MC-Pa on DKD from the gut microbiota perspective. The DKD rat model was induced by a high-fat and high-sugar diet combined with streptozotocin (STZ). The rats were then supplemented with MC-Pa (80 and 160 mg/kg BW) for 12 weeks. The results showed that MC-Pa administration relieved hyperglycemia and renal injury in DKD rats. MC-Pa also reconstructed gut microbiota, improved intestinal barrier function, reduced serum proinflammatory mediators, and elevated the short-chain fatty acid (SCFAs) contents. In addition, the dynamics of Lactobacillus and Muribaculaceae_unclassified were in a dose- and time-dependent manner. Spearman correlation analysis found that a cluster of gut microbiota phyla and genera were significantly associated with DKD-related indicators. These results demonstrated that MC-Pa positively affected DKD rats by modulating gut microbiota dynamically and had potential as a prebiotic.

EPA-Enriched Phospholipids Alleviate Renal Interstitial Fibrosis in Spontaneously Hypertensive Rats by Regulating TGF-β Signaling Pathways

Hypertensive nephropathy is a chronic kidney disease caused by hypertension. Eicosapentaenoic acid (EPA) has been reported to possess an antihypertensive effect, and our previous study suggested that EPA-enriched phospholipid (EPA-PL) had more significant bioactivities compared with traditional EPA. However, the effect of dietary EPA-PL on hypertensive nephropathy has not been studied. The current study was designed to examine the protection of EPA-PL against kidney damage in spontaneously hypertensive rats (SHRs). Treatment with EPA-PL for three weeks significantly reduced blood pressure through regulating the renin–angiotensin system in SHRs. Moreover, dietary EPA-PL distinctly alleviated kidney dysfunction in SHRs, evidenced by reduced plasma creatinine, blood urea nitrogen, and 24 h proteinuria. Histology results revealed that treatment of SHRs with EPA-PL alleviated renal injury and reduced tubulointerstitial fibrosis. Further mechanistic studies indicated that dietary EPA-PL remarkably inhibited the activation of TGF-β and Smad 3, elevated the phosphorylation level of PI3K/AKT, suppressed the activation of NF-κB, reduced the expression of pro-inflammatory cytokines, including IL-1β and IL-6, and repressed the oxidative stress and the mitochondria-mediated apoptotic signaling pathway in the kidney. These results indicate that EPA-PL has potential value in the prevention and alleviation of hypertensive nephropathy.

The effects of angiotensin I-converting enzyme inhibitory peptide VGINYW and the hydrolysate of α-lactalbumin on blood pressure, oxidative stress and gut microbiota of spontaneously hypertensive rats

VGINYW is a highly active angiotensin I-converting enzyme (ACE) inhibitory peptide discovered from α-lactalbumin by an in vitro-in silico high throughput screening strategy. The aim of this study was to evaluate the antihypertensive effect of the peptide and the α-lactalbumin hydrolysates under 3 kDa (LH-3k), and illustrate the possible mechanism in spontaneously hypertensive rats (SHRs). SHRs were administered with VGINYW and LH-3k at doses of 5 mg per kg BW and 100 mg per kg BW, respectively. VGINYW and LH-3k could markedly decrease the systolic blood pressure (SBP) of the SHRs, and the maximal drops of 21 mmHg (2 h after administration) and 17 mmHg (4 h after administration) were achieved during the 8 hour test, respectively. When the agents were given once per day for 4 weeks, they caused a long-term decrease of 16 mmHg of SBP. VGINYW and LH-3k control the blood pressure through regulating the renin-angiotensin system by inhibiting the ACE activity and diminishing the angiotensin II level, and further upregulating the expression levels of the angiotensin-converting enzyme 2 and angiotensin type 2 receptor, and downregulating the expression of the angiotensin type 1 receptor. VGINYW and LH-3k could notably ameliorate the oxidative stress in the SHR as well. It is more important that the gavage of VGINYW and LH-3k could alleviate hypertension-associated intestinal microbiota dysbiosis by recovering the diversity of the gut microbiota and altering the key floras which are short chain fatty acid producers. In conclusion, VGINYW and LH-3k are effective functional ingredients for blood pressure control.

An updated review on food-derived bioactive peptides: Focus on the regulatory requirements, safety, and bioavailability

Food-derived bioactive peptides (BAPs) are recently utilized as functional food raw materials owing to their potential health benefits. Although there is a huge amount of scientific research about BAPs' identification, purification, characterization, and physiological functions, and subsequently, many BAPs have been marketed, there is a paucity of review on the regulatory requirements, bioavailability, and safety of BAPs. Thus, this review focuses on the toxic peptides that could arise from their primary proteins throughout protein extraction, protein pretreatment, and BAPs' formulation. Also, the influences of BAPs' length and administration dosage on safety are summarized. Lastly, the challenges and possibilities in BAPs' bioavailability and regulatory requirements in different countries were also presented. Results revealed that the human studies of BAPs are essential for approvals as healthy food and to prevent the consumers from misinformation and false promises. The BAPs that escape the gastrointestinal tract epithelium and move to the stomach are considered good peptides and get circulated into the blood using different pathways. In addition, the hydrophobicity, net charge, molecular size, length, amino acids composition/sequences, and structural characteristics of BAPs are critical for bioavailability, and appropriate food-grade carriers can enhance it. The abovementioned features are also vital to optimize the solubility, water holding capacity, emulsifying ability, and foaming property of BAPs in food products. In the case of safety, the possible allergenic and toxic peptides often exhibit physiological functions and could be produced during the hydrolysis of food proteins. It was also noted that the production of iso-peptides bonds and undesirable Maillard reaction might occur during protein extraction, sample pretreatments, and peptide synthesis.

Peanut meal extract fermented with Bacillus natto attenuates physiological and behavioral deficits in a D-galactose-induced aging rat model

Our previous studies have shown that the nutritional properties of peanut meal after fermentation are markedly improved. In this study, in order to facilitate the further utilization of peanut meal, we investigated the effects of its fermentation extract by Bacillus natto (FE) on cognitive ability, antioxidant activity of brain, and protein expression of hippocampus of aging rats induced by D-galactose. Seventy-two female SD rats aged 4-5 months were randomly divided into six groups: normal control group (N), aging model group (M), FE low-dose group (FL), FE medium-dose group (FM), FE high-dose group (FH) and vitamin E positive control group (Y). Morris water maze (MWM) test was performed to evaluate their effects on learning and memory ability in aging rats. SOD activity and malondialdehyde (MDA) content of brain, HE staining and the expression of γ-aminobutyric acid receptor 1 (GABABR1) and N-methyl-D-aspartic acid 2B receptor (NMDAR2B) in the hippocampus of rats were measured. The results show that FE supplementation can effectively alleviate the decrease of thymus index induced by aging, decrease the escape latency of MWM by 66.06%, brain MDA by 28.04%, hippocampus GABABR1 expression by 7.98%, and increase brain SOD by 63.54% in aging model rats. This study provides evidence for its anti-aging effects and is a research basis for potential nutritional benefits of underutilized food by-products.