Pyropia columbina phycocolloids as microencapsulating material improve bioaccessibility of brewers’ spent grain peptides with ACE‐I inhibitory activity

Identification of bioaccessible glycosylated neuroprotective peptides from brewer's spent yeast mannoproteins by in vitro and in silico studies

The aims of this work were to purify mannoproteins from brewer's spent yeast, to evaluate the neuroprotective and antioxidant properties of peptides generated by a simulated gastrointestinal digestion (SGID), and to identify the peptides responsible of acetylcholinesterase (AChE), tyrosinase (TYR), prolyl oligopeptidase (POP) and ABTS+ inhibitory activity using tandem mass spectrometry and in silico analysis. Mannoproteins from brewer's spent yeast were purified using the simultaneous effect of ethanol and pH on protein solubility followed by ultrafiltration process (10 kDa). The retained fraction (> 10 kDa) showed 80.5 ± 5.8 g protein 100 g-1 solids, of which 71.2 ± 1.0 g 100 g-1 were mannoprotein. The SGID of isolated mannoproteins released peptides with AChE, TYR, POP and ABTS+ inhibitory activity. Peptides released from mannoproteins showed strong inhibitory activity against TYR by diphenolase mechanism. These bioactivities were related to low MW mannose-linked peptides. After identification, the NEPGCYF peptide showed the highest in silico blood-brain barrier penetrating property (B3Pred score: 0.70) and in silico free radical scavenger activity (FRS score: 0.54) among mannose-linked peptides. Molecular docking indicated that this peptide acted as competitive inhibitor for AChE and POP enzymes, and as non-competitive inhibitor for TYR enzyme. These mechanisms were confirmed by in vitro kinetic analysis using the inhibitory mannose-linked peptides and the synthetic peptide NEPGCYF. Purified mannoproteins from brewer's spent yeast are a promising source of bioaccessible glycosylated peptides with good neuroprotective and antioxidant properties.

Recent advances in the effect of simulated gastrointestinal digestion and encapsulation on peptide bioactivity and stability

Food-derived bioactive peptides have garnered significant attention from researchers due to their specific biological functions, including antihypertensive, antioxidant, antidiabetic, anticancer, anti-inflammatory, and anti-osteoporosis properties. Despite extensive in vitro research, the bioactivity of these peptides may be compromised in the gastrointestinal tract due to enzymatic hydrolysis before reaching the bloodstream or target cells. Therefore, understanding the fate of bioactive peptides during digestion is crucial before advancing to clinical trials and commercial applications. To exert their health-promoting effects, these peptides must maintain their bioactivity throughout digestion. Encapsulation has emerged as a promising strategy for protecting peptides in the gastrointestinal tract. This review examines the effects of in vitro simulated gastrointestinal digestion on peptide bioactivity and stability, highlighting recent research on encapsulation strategies designed to enhance their gastrointestinal stability. Furthermore, the review addresses existing research gaps and suggests future research directions to advance our understanding and the application of bioactive peptides.

Casein Glycomacropeptide Regulates Gene Expression in Intestinal Epithelial Cells: Effect of Simulated Gastrointestinal Digestion and Peptide Microencapsulation

κ-Casein glycomacropeptide (GMP) exerts anti-inflammatory and immune modulatory effects. A bovine GMP concentrate and its in vitro digestion product were obtained. GMP was also microencapsulated with phycocolloids and further digested. These products were tested in three-dimensional (3D) and open monolayer two-dimensional (2D) mouse jejunal organoids. Almost no effect was observed on the 2D organoids. In 3D organoids, GMP induced intestinal proliferation (Axin2, Pcna) and differentiation (Vil1, Alpl) genes together with Muc3, antibacterial genes (Lyz1, Pla2g2a), and Cxcl1. GMP also induced interferon I defense genes (Ifnb1, Ifr3, Oas2, Oas3, Rnasel) under basal conditions and in TNF-stimulated organoids. In vitro digestion abrogated the effects of GMP and induced new genes (Lgr5, Olfm4, and Lct). In TNF-stimulated organoids, digested GMP repressed multiple genes. Encapsulation largely preserved the GMP effects. In conclusion, GMP showed differential effects in 3D and 2D organoids. The effects of digestion peptides were also different, suggesting distinct potential as functional foods.

A Comprehensive Review of Challenges in Oral Drug Delivery Systems and Recent Advancements in Innovative Design Strategies

The oral route of drug administration is often preferred by patients and healthcare providers due to its convenience, ease of use, non-invasiveness, and patient acceptance. However, traditional oral dosage forms have several limitations, including low bioavailability, limited drug loading capacity, and stability and storage issues, particularly with solutions and suspensions. Over the years, researchers have dedicated considerable effort to developing novel oral drug delivery systems to overcome these limitations. This review discusses various challenges associated with oral drug delivery systems, including biological, pharmaceutical, and physicochemical barriers. It also explores common delivery approaches, such as gastroretentive drug delivery, small intestine drug delivery, and colon-targeting drug delivery systems. Additionally, numerous strategies aimed at improving oral drug delivery efficiency are reviewed, including solid dispersion, absorption enhancers, lipidbased formulations, nanoparticles, polymer-based nanocarriers, liposomal formulations, microencapsulation, and micellar formulations. Furthermore, innovative approaches like orally disintegrating tablets (ODT), orally disintegrating films (ODF), layered tablets, micro particulates, self-nano emulsifying formulations (SNEF), and controlled release dosage forms are explored for their potential in enhancing oral drug delivery efficiency and promoting patients' compliance. Overall, this review highlights significant progress in addressing challenges in the pharmaceutical industry and clinical settings, offering novel approaches for the development of effective oral drug delivery systems.

Anti-diabetic properties of brewer's spent yeast peptides. In vitro, in silico and ex vivo study after simulated gastrointestinal digestion

Brewer's spent yeast (BSY) hydrolysates are a source of antidiabetic peptides. Nevertheless, the impact of in vitro gastrointestinal digestion of BSY derived peptides on diabetes has not been assessed. In this study, two BSY hydrolysates were obtained (H1 and H2) using β-glucanase and alkaline protease, with either 1 h or 2 h hydrolysis time for H1 and H2, respectively. These hydrolysates were then subjected to simulated gastrointestinal digestion (SGID), obtaining dialysates D1 and D2, respectively. BSY hydrolysates inhibited the activity of α-glucosidase and dipeptidyl peptidase IV (DPP-IV) enzymes. Moreover, although D2 was inactive against these enzymes, D1 IC50 value was lower than those found for the hydrolysates. Interestingly, after electrophoretic separation, D1 mannose-linked peptides showed the highest α-glucosidase inhibitory activity, while non-glycosylated peptides had the highest DPP-IV inhibitory activity. Kinetic analyses showed a non-competitive mechanism in both cases. After peptide identification, GILFVGSGVSGGEEGAR and IINEPTAAAIAYGLDK showed the highest in silico anti-diabetic activities among mannose-linked and non-glycosylated peptides, respectively (AntiDMPpred score: 0.70 and 0.77). Molecular docking also indicated that these peptides act as non-competitive inhibitors. Finally, an ex vivo model of mouse jejunum organoids was used to study the effect of D1 on the expression of intestinal epithelial genes related to diabetes. The reduction of the expression of genes that codify lactase, sucrase-isomaltase and glucose transporter 2 was observed, as well as an increase in the expression of Gip (glucose-dependent insulinotropic peptide) and Glp1 (glucagon-like peptide 1). This is the first report to evaluate the anti-diabetic effect of BSY peptides in mouse jejunum organoids.

Xanthan gum and pectin as beverage stabilizers reduce the digestive enzyme hydrolysis of antioxidant and antihypertensive peptides obtained from a brewery byproduct

An acidic beverage was formulated with xanthan gum (XG), pectin (P) and brewer spent grain (BSG) peptides with antioxidant and antihypertensive properties. The impact of hydrocolloids levels on peptide bioaccessibility was studied. Peptides were obtained from BSG using Purazyme and Flavourzyme enzymes. BSG peptides were fractionated by ultrafiltration (UF) and four fractions were obtained: F1 (>10 kDa), F2 (10-5 kDa), F3 (1-5 kDa), and F4 (<1 kDa). F3 showed the highest protein purity, ferulic acid content, proportion of amphipathic peptides, and bioactive properties (ABTS+ radical scavenging and ACE-I inhibitory activity). The identified peptides from F3 by tandem mass spectrometry were 138. In silico analysis showed that 26 identified peptides had ABTS+ inhibitory activity, while 59 ones presented good antihypertensive properties. The effect of XG and P levels on bioaccessibility of F3 peptides in the formulated beverages was studied by a central composite experimental design. It was observed that F3 peptides interacted with hydrocolloids by electrostatic forces at pH of formulated beverages. The addition of hydrocolloids to formulation modulated the release of the antioxidant peptides and protected the degradation of ACE-I inhibitory peptides from F3 during simulated gastrointestinal digestion. Finally, the level of hydrocolloids that produced intermediate viscosities in the formulated beverages improved the bioaccessibility of the F3 peptides.

Encapsulation of Bioactive Peptides by Spray-Drying and Electrospraying

Bioactive peptides derived from enzymatic hydrolysis are gaining attention for the production of supplements, pharmaceutical compounds, and functional foods. However, their inclusion in oral delivery systems is constrained by their high susceptibility to degradation during human gastrointestinal digestion. Encapsulating techniques can be used to stabilize functional ingredients, helping to maintain their activity after processing, storage, and digestion, thus improving their bioaccessibility. Monoaxial spray-drying and electrospraying are common and economical techniques used for the encapsulation of nutrients and bioactive compounds in both the pharmaceutical and food industries. Although less studied, the coaxial configuration of both techniques could potentially improve the stabilization of protein-based bioactives via the formation of shell-core structures. This article reviews the application of these techniques, both monoaxial and coaxial configurations, for the encapsulation of bioactive peptides and protein hydrolysates, focusing on the factors affecting the properties of the encapsulates, such as the formulation of the feed solution, selection of carrier and solvent, as well as the processing conditions used. Furthermore, this review covers the release, retention of bioactivity, and stability of peptide-loaded encapsulates after processing and digestion.

Recent Progress in Microencapsulation of Active Peptides-Wall Material, Preparation, and Application: A Review

Being a natural active substance with a wide variety of sources, easy access, significant curative effect, and high safety, active peptides have gradually become one of the new research directions in food, medicine, agriculture, and other fields in recent years. The technology associated with active peptides is constantly evolving. There are obvious difficulties in the preservation, delivery, and slow release of exposed peptides. Microencapsulation technology can effectively solve these difficulties and improve the utilization rate of active peptides. In this paper, the commonly used materials for embedding active peptides (natural polymer materials, modified polymer materials, and synthetic polymer materials) and embedding technologies are reviewed, with emphasis on four new technologies (microfluidics, microjets, layer-by-layer self-assembly, and yeast cells). Compared with natural materials, modified materials and synthetic polymer materials show higher embedding rates and mechanical strength. The new technology improves the preparation efficiency and embedding rate of microencapsulated peptides and makes the microencapsulated particle size tend to be controllable. In addition, the current application of peptide microcapsules in different fields was also introduced. Selecting active peptides with different functions, using appropriate materials and efficient preparation technology to achieve targeted delivery and slow release of active peptides in the application system, will become the focus of future research.

Microencapsulated bioactive peptides from brewer's spent grain promotes antihypertensive and antidiabetogenic effects on a hypertensive and insulin-resistant rat model

The effects of microcapsules containing brewer's spent grain (BSG) peptides were evaluated on a hypertensive/insulin-resistant rat model induced by a sucrose-rich diet (SRD) administration. Animals received for 100 days the control diet (CD), SRD, and CD and SRD diets supplemented with microencapsulated peptides (CD-P and SRD-P). During the experimental period, blood pressure was monitored. Glycemia, tissue glycogen content, nitric oxide, and the activity of enzymes related to hypertensive and diabetogenic mechanisms were determined. The consumption of SRD caused hypertensive and hyperglycemic effects compared to CD. However, the SRD-P group presented lower systolic pressure at the middle of ingestion, achieving similar values than the CD. The SRD-P rats decreased all enzymes' activities compared to the SRD reaching the values of CD, except for those of α-amylase in cecal content and DPP-IV in serum. It was possible to corroborate potential antihypertensive and antidiabetogenic in vivo effects of the microencapsulated BSG peptides. PRACTICAL APPLICATIONS: Brewer's spent grain (BSG) is the main waste obtained from brewing industry. Bioactive peptides obtained after an enzymatic hydrolysis of proteins with in vitro antihypertensive and antidiabetogenic activity have been described. However, to corroborate the action of these bioactive peptides, in vivo studies are necessary. In the present work, microcapsules containing bioactive peptides from BSG were administered on the rat model with induced hypertension and insulin-resistance, corroborating an in vivo antihypertensive and antidiabetogenic effects by inhibition of enzymes related with blood pressure regulation and glucose metabolism. This work demonstrated that microcapsules of BSG peptides could be included into functional foods formulations, or used as dietary supplement for improving health and the prevention of non-communicable diseases, adding value to the brewing process by-product.

Current Evidence on the Bioavailability of Food Bioactive Peptides

Food protein-derived bioactive peptides are recognized as valuable ingredients of functional foods and/or nutraceuticals to promote health and reduce the risk of chronic diseases. However, although peptides have been demonstrated to exert multiple benefits by biochemical assays, cell culture, and animal models, the ability to translate the new findings into practical or commercial uses remains delayed. This fact is mainly due to the lack of correlation of in vitro findings with in vivo functions of peptides because of their low bioavailability. Once ingested, peptides need to resist the action of digestive enzymes during their transit through the gastrointestinal tract and cross the intestinal epithelial barrier to reach the target organs in an intact and active form to exert their health-promoting properties. Thus, for a better understanding of the in vivo physiological effects of food bioactive peptides, extensive research studies on their gastrointestinal stability and transport are needed. This review summarizes the most current evidence on those factors affecting the digestive and absorptive processes of food bioactive peptides, the recently designed models mimicking the gastrointestinal environment, as well as the novel strategies developed and currently applied to enhance the absorption and bioavailability of peptides.

Isolation and identification of cholesterol esterase and pancreatic lipase inhibitory peptides from brewer's spent grain by consecutive chromatography and mass spectrometry

The isolation and identification of cholesterol esterase (CE) and pancreatic lipase (PL) inhibitory peptides obtained from the protein hydrolysate of brewer's spent grain (BSG) was performed. BSG peptides were fractionated and purified sequentially by anion exchange, gel filtration (FPLC), and reversed phase high-performance liquid chromatography (RP-HPLC). The fractions obtained from each chromatographic step were collected and the in vitro enzyme inhibitory activity was evaluated. The chromatographic purification process increased the in vitro activities. The most active fractions were evaluated using MALDI-TOF tandem mass spectrometry, which identified three peptides: a peptide with the highest CE inhibition capacity (WNIHMEHQDLTTME) and two peptides with PL inhibition capacity (DFGIASF and LAAVEALSTNG). These three peptides showed hydrophobic and acidic amino acid residues (Asp and Glu) and/or their amines (Asn and Gln), which could be a common feature among lipid-lowering peptides related to CE and PL enzyme inhibition. The in silico studies showed that the three peptides had high hydrophobicity and were susceptible to enzymatic hydrolysis performed by trypsin, pepsin, and pancreatin. The BSG byproduct was a good source of CE and PL inhibitory peptides, thus adding value to this byproduct of the beer industry. This is the first report to demonstrate that BSG peptides can inhibit CE and PL enzymes.