Combinations of Legume Protein Hydrolysates Synergistically Inhibit Biological Markers Associated with Adipogenesis

Gastrointestinal digestion of food proteins: Anticancer, antihypertensive, anti-obesity, and immunomodulatory mechanisms of the derived peptides

Food proteins and their peptides play a significant role in the important biological processes and physiological functions of the body. The peptides show diverse biological benefits ranging from anticancer to antihypertensive, anti-obesity, and immunomodulatory, among others. In this review, an overview of food protein digestion in the gastrointestinal tract and the mechanisms involved was presented. As some proteins remain resistant and undigested, the multifarious factors (e.g. protein type and structure, microbial composition, pH levels and redox potential, host factors, etc.) affecting their colonic fermentation, the derived peptides, and amino acids that evade intestinal digestion are thus considered. The section that follows focuses on the mechanisms of the peptides with anticancer, antihypertensive, anti-obesity, and immunomodulatory effects. As further considerations were made, it is concluded that clinical studies targeting a clear understanding of the gastrointestinal stability, bioavailability, and safety of food-based peptides are still warranted.

Enhancing the stability and therapeutic potential of the antimicrobial peptide Feleucin-K3 against Multidrug-Resistant a. Baumannii through rational utilization of a D-amino acid substitution strategy

Antimicrobial peptides (AMPs), which have a low probability of developing resistance, are considered the most promising antimicrobial agents for combating antibiotic resistance. Feleucin-K3 is an amphiphilic cationic AMP that exhibits broad-spectrum antimicrobial activity. In our previous research, the first phenylalanine residue was identified as the critical position affecting its biological activity. Here, a series of Feleucin-K3 analogs containing hydrophobic D-amino acids were developed, leveraging the low sensitivity of proteases to unnatural amino acids and the regulatory effect of hydrophobicity on antimicrobial activity. Among them, K-1dF, which replaced the phenylalanine of Feleucin-K3 with its enantiomer (D-phenylalanine), exhibited potent antimicrobial activity with a therapeutic index of 46.97 and MICs between 4 to 8 μg/ml against both sensitive and multidrug-resistant Acinetobacter baumannii. The introduction of D-phenylalanine increased the salt tolerance and serum stability of Feleucin-K3. Moreover, K-1dF displayed a rapid bactericidal effect, a low propensity to develop resistance, and a synergistic effect when combined with antibiotics. More importantly, it exhibited considerable or superior efficacy to imipenem against pneumonia and skin abscess infection. In brief, the K-1dF obtained by simple and effective modification strategy has emerged as a promising candidate antimicrobial agent for tackling multidrug-resistant Acinetobacter baumannii infections.

Native Mexican black bean purified anthocyanins fractionated by high-performance counter-current chromatography modulate inflammatory pathways

In addition to their pigment properties, the potential health benefits of anthocyanins have made them a subject of interest in recent years. This study aimed to obtain purified anthocyanin fractions from native Mexican black bean cultivars using Amberlite XAD-7 resin column and HPCCC and evaluate their anti-inflammatory properties using RAW 264.7 cells. The major anthocyanins in the purified anthocyanin fractions were delphinidin 3-glucoside (61.8%), petunidin 3-glucoside (25.2%), and malvidin 3-glucoside (12.2%). Purified anthocyanin fractions at 12.5 μg/mL effectively prevented LPS-induced ERK1/ERK2 phosphorylation and reduced the protein expression of COX-2 and mRNA expression of iNOS. Results showed that purified anthocyanin fractions have the potential to modulate the inflammatory response by inhibiting the production of pro-inflammatory mediators through the ERK1/ERK2 and NF-κB pathways. This study suggests that anthocyanins from black beans could be used as a natural strategy to help modulate inflammation-associated diseases.

Germinated chickpea protein ficin hydrolysate and its peptides inhibited glucose uptake and affected the bitter receptor signaling pathway in vitro

The objective of this study was to evaluate germinated chickpea protein hydrolysate (GCPH) in vitro for its effect on markers of type 2 diabetes (T2D) and bitter taste receptor expression in intestinal epithelial cells. Protein hydrolysate was obtained using ficin, and the resulting peptides were sequenced using LC-ESI-MS/MS. Caco-2 cells were used to determine glucose uptake and extra-oral bitter receptor activation. Three peptides, VVFW, GEAGR, and FDLPAL, were identified in legumin. FDLPAL was the most potent peptide in molecular docking studies with a DPP-IV energy of affinity of -9.8 kcal mol-1. GCPH significantly inhibited DPP-IV production by Caco-2 cells (IC50 = 2.1 mM). Glucose uptake was inhibited in a dose-dependent manner (IC25 = 2.0 mM). A negative correlation was found between glucose uptake and PLCβ2 expression in Caco-2 cells (R value, -0.62). Thus, GCPH has the potential to be commercialized as a functional ingredient.

Selected Soybean Varieties Regulate Hepatic LDL-Cholesterol Homeostasis Depending on Their Glycinin:β-Conglycinin Ratio

Clinical studies indicate that the consumption of soybean protein might reduce cholesterol and LDL levels preventing the development of atherosclerotic cardiovascular diseases. However, soybean variety can influence soybean protein profile and therefore affect soybean protein health-promoting properties. This study investigated the composition and effects of nineteen soybean varieties digested under simulated gastrointestinal conditions on hepatic cholesterol metabolism and LDL oxidation in vitro. Soybean varieties exhibited a differential protein hydrolysis during gastrointestinal digestion. Soybean varieties could be classified according to their composition (high/low glycinin:β-conglycinin ratio) and capacity to inhibit HMGCR (IC50 from 59 to 229 µg protein mL−1). According to multivariate analyses, five soybean varieties were selected. These soybean varieties produced different peptide profiles and differently reduced cholesterol concentration (43−55%) by inhibiting HMGCR in fatty-acid-stimulated HepG2 hepatocytes. Selected digested soybean varieties inhibited cholesterol esterification, triglyceride production, VLDL secretion, and LDL recycling by reducing ANGPTL3 and PCSK9 and synchronously increasing LDLR expression. In addition, selected soybean varieties hindered LDL oxidation, reducing the formation of lipid peroxidation early (conjugated dienes) and end products (malondialdehyde and 4-hydroxynonenal). The changes in HMGCR expression, cholesterol esterification, triglyceride accumulation, ANGPTL3 release, and malondialdehyde formation during LDL oxidation were significantly (p < 0.05) correlated with the glycinin:β-conglycinin ratio. Soybean varieties with lower glycinin:β-conglycinin exhibited a better potential in regulating cholesterol and LDL homeostasis in vitro. Consumption of soybean flour with a greater proportion of β-conglycinin may, consequently, improve the potential of the food ingredient to maintain healthy liver cholesterol homeostasis and cardiovascular function.

Interactions between Hazelnut (Corylus avellana L.) Protein and Phenolics and In Vitro Gastrointestinal Digestibility

In this study, we investigated the formation of protein–phenolic complexes from dephenolized hazelnut meal protein isolates (dHPI) and hazelnut skin phenolic extracts (HSE) and their effects on the bioaccessibility of both hazelnut proteins and phenolics. The dHPI–HSE complexes were of considerable size and were dependent on HSE concentration due to aggregation. Although catechin was the main component of HSE, it did not cause aggregation, except for a slight rise in particle size. According to fluorescence quenching, the hazelnut protein–phenolic extract complex had a linear Stern–Volmer plot expressing static quenching between 0–0.5 mM concentration; the interaction was mainly dependent on hydrogen bonding and van der Waals forces (ΔH < 0 and ΔS < 0), and the reaction was spontaneous (ΔG < 0). According to Fourier transform infrared (FTIR) spectroscopy results, higher phenolic extract concentration caused an increase in irregular structures in hazelnut protein, while the lowest catechin and phenolic concentration altered the regular structure. Skin extracts did not alter the digestibility of dephenolized proteins, but dephenolization reduced the degree of hydrolysis by pancreatin. The formation of the protein–phenolic complex had a beneficial effect on the bioaccessibility of hazelnut skin phenols, predominantly those on the galloylated form of the catechins, such as gallocatechin gallate and epigallocatechin gallate. Thus, the bioaccessibility and antioxidant activity analysis results showed that protein–phenolic complexes obtained from hazelnut meal and skin may promote the transition of phenolic compounds from the gastrointestinal tract without degradation.

Bioactive and health-promoting properties of enzymatic hydrolysates of legume proteins: a review

This study comprehensively reviewed the effect of controlled enzymatic hydrolysis on the bioactivity of pulse protein hydrolysates (PPHs). Proteolysis results in the partial structural unfolding of pulse proteins with an increase in buried hydrophobic groups of peptide sequences. The use of PPHs in a dose-dependent manner can enhance free radical scavenging and improve antioxidant activities regarding inhibition of lipid oxidation, ferric reducing power, metal ion chelation, and β-carotene bleaching inhibition. Ultrafiltered peptide fractions with low molecular weights imparted angiotensin-I converting enzyme (ACE) inhibitory effects during in vitro simulated gastrointestinal digestion and in vivo conditions. Ultrasonication, high-pressure pretreatments, and glycosylation as post-treatments can improve the antiradical, antioxidant, and ACE inhibitory activities of PPHs. The electrostatic attachment of pulse peptides to microbial cells can inhibit the growth and activity of bacteria and fungi. Bioactive pulse peptides can reduce serum cholesterol and triglycerides, and inhibit the formation of adipocyte lipid storage, allergenic factors, inflammatory markers, and arterial thrombus without cytotoxicity. The combination of germination and enzymatic hydrolysis can significantly increase the protein digestibility and bioavailability of essential amino acids. Moreover, the utilization and enrichment of bakery and meat products with functional PPHs ensure quality, safety, and health aspects of food products.

Biological functions of peptides from legumes in gastrointestinal health. A review legume peptides with gastrointestinal protection

Extensively consumed worldwide, legumes such as beans, soybeans, chickpeas, and peas represent a great source of protein. Legume-derived proteins provide bioactive peptides, small sequences of amino acids produced by enzymatic hydrolysis, gastrointestinal digestion, fermentation, or germination. Recent studies showed diverse biological effects of these peptides as antioxidants, antihypertensives, anti-inflammatory, antimicrobial, antithrombotic, antidiabetic, hypocholesterolemic, and even immunomodulators. These beneficial effects aid in preventing and treating chronic illnesses, particularly inflammatory disorders, obesity, and cardiovascular diseases. Thus, this work discusses these biological functions in gastrointestinal digestion health of bioactive peptides obtained from common beans, soybeans, chickpeas, peas, and other legumes. PRACTICAL APPLICATIONS: Knowledge of the nutraceutical properties of legumes can encourage the use of these seeds as ingredients in the development and design of functional foods.

Extraction and Characterization of β-Viginin Protein Hydrolysates from Cowpea Flour as a New Manufacturing Active Ingredient

The increased mortality rates associated with antibiotic resistance has become a significant public health problem worldwide. Living beings produce a variety of endogenous compounds to defend themselves against exogenous pathogens. The knowledge of these endogenous compounds may contribute to the development of improved bioactive ingredients with antimicrobial properties, useful against conventional antibiotic resistance. Cowpea is an herbaceous legume of great interest due to its high protein content and high productivity rates. The study of genetic homology of vicillin (7S) from cowpea (Vigna unguiculata L.) with vicilins from soybean and other beans, such as adzuki, in addition to the need for further studies about potential biological activities of this vegetable, led us to seek the isolation of the vicilin fraction from cowpea and to evaluate the potential in vitro inhibitory action of pathogenic microorganisms. The cowpea beta viginin protein was isolated, characterized, and hydrolyzed in silico and in vitro by two enzymes, namely, pepsin and chymotrypsin. The antimicrobial activity of the protein hydrolysate fractions of cowpea flour was evaluated against Staphylococcus aureus and Pseudomonas aeruginosa, confirming the potential use of the peptides as innovative antimicrobial agents.

The Protein-Rich Powdered Beverages Stabilized with Flax Seeds Gum—Antioxidant and Antiproliferative Properties of the Potentially Bioaccessible Fraction

The functional beverages market is one of the fastest-growing sectors of functional food production. An innovative recipe for powdered fruit and vegetable drinks fortified with lentil proteins (AGF) and stabilized with flax seed gums (FSG) was developed. The study focused on the analysis of potentially bioaccessible fractions from the produced beverages in terms of their antioxidant, antiproliferative activities and physicochemical properties. The contents of bioactive components were tailored by the incorporation of lyophilized fruits and vegetables, the FSG and the AGF. Digestion in vitro effectively released phenolics from all matrices. The highest contents of potentially bioavailable polyphenols were recorded for the AGF based beverages enriched with 5% of FSG and green-leafy vegetables (58 mg/100 mL) and those with lyophilized fruit (54 mg/100 mL). The reducing power of the beverages was mainly affected by the presence of the AGF, while the FSG and lyophilized fruit improved the chelating power. The digests applied in the concentrations mimicking physiological concentrations showed antiproliferative properties against gastric and colon adenocarcinoma—they seemed to be tailored by bioactive peptides and phenolics, respectively. The addition of the FSG improved the stability of the beverages increasing the time required for a reduction of 20% of the initial optical density by 16- and 28-times in the beverages without additives or enriched with vegetables. Both, the AGF and FSG stabilize the beverages after rehydration and are sources of bioaccessible antioxidant and anticancer components, which create their functionality.

Application of emerging technologies to obtain legume protein isolates with improved techno-functional properties and health effects

Current demand of consumers for healthy and sustainable food products has led the industry to search for different sources of plant protein isolates and concentrates. Legumes represent an excellent nonanimal protein source with high-protein content. Legume species are distributed in a wide range of ecological conditions, including regions with drought conditions, making them a sustainable crop in a context of global warming. However, their use as human food is limited by the presence of antinutritional factors, such as protease inhibitors, lectins, phytates, and alkaloids, which have adverse nutritional effects. Antitechnological factors, such as fiber, tannins, and lipids, can affect the purity and protein extraction yield. Although most are removed or reduced during alkaline solubilization and isoelectric precipitation processes, some remain in the resulting protein isolates. Selection of appropriate legume genotypes and different emerging and sustainable facilitating technologies, such as high-power ultrasound, pulsed electric fields, high hydrostatic pressure, microwave, and supercritical fluids, can be applied to increase the removal of unwanted compounds. Some technologies can be used to increase protein yield. The technologies can also modify protein structure to improve digestibility, reduce allergenicity, and tune technological properties. This review summarizes recent findings regarding the use of emerging technologies to obtain high-purity protein isolates and the effects on techno-functional properties and health.

Phytochemicals: Dietary Sources, Innovative Extraction, and Health Benefits

Plants are the main natural source of numerous phytochemicals, although only a certain amount have been isolated and identified [...].