From In Silico to a Cellular Model: Molecular Docking Approach to Evaluate Antioxidant Bioactive Peptides

In vitro evaluation of multifunctional peptides PW, PF, PPG, PM, IW, and SW for metabolic syndrome management

Multifunctional peptides derived from various food sources, including ancestral grains, hold significant promise for managing metabolic syndrome. These bioactive peptides exhibit diverse properties that collectively contribute to improving the components of metabolic syndrome. In this study, we investigated the in vitro multifunctionality of six peptides (PW, PM, SW, PPG, PW, and IW) identified through in silico analysis and chemically synthesized. These peptides were evaluated for their potential to address metabolic syndrome-related activities such as antidiabetic, antiobesity, antihypertensive, and antioxidative properties. Assessment included their capacity to inhibit key enzymes associated with these activities, as well as their free radical scavenging and cellular antioxidative activities. Principal component analysis was employed to cluster the peptides according to their multifunctionality. Our results revealed that peptides containing tryptophan (SW, PW, and IW) exhibited the most promising multifunctional attributes, with SW showing particularly high potential. This multifunctional peptide represents a promising avenue for addressing metabolic syndrome.

Defatted Wheat Germ Protein-Derived Peptides Showed Multiple Biological Activities from the Stomach to Small Intestine: In Silico and In Vitro Approaches

This study aimed to test the hypothesis that bioactive peptides can exert multiple bioactivities at different sites in the gastrointestinal tract. Our previous research identified 33 gastric-resistant peptides derived from wheat germ with potential antiadhesive activity against Helicobacter pylori in the stomach. In this work, in silico digestion of these peptides with trypsin, thermolysin, and chymotrypsin produced 67 peptide fragments. Molecular docking was conducted to predict their ACE and DPP-IV inhibitory activities in the small intestine. Three peptides (VPIPNPSGDR, VPY, and AR) were selected and synthesized for in vitro validation. Their generation in the gastrointestinal tract was verified via in vitro digestion, followed by mass spectrometry analysis. The IC50 values for ACE inhibition were 199.5 μM (VPIPNPSGDR), 316.3 μM (VPY), and 446.7 μM (AR). For DPP-IV inhibition, their IC50 values were 0.5, 1.6, and 4.0 mM, respectively. This research pioneers new directions in the emerging field of multifunctional peptides, providing scientific evidence to support the utilization of wheat germ as value-added food ingredients.

Four novel anti-adhesive activity peptides against Helicobacter pylori derived from rice bran protein: release, identification and anti-adhesive mechanisms elucidation

H. pylori is a highly pathogenic and prevalent pathogen that is a class I carcinogen. More than 50% of the world's population is infected with H. pylori. An anti-adhesive strategy is an effective way to antagonize H. pylori infection, which does not cause H. pylori resistance and is safer compared to antibiotic therapy. In the present study, to obtain rice bran protein-derived anti-adhesive activity peptides against H. pylori, an efficient enzymatic hydrolysis system was established, and it was found that rice bran protein hydrolysate prepared under specific conditions possessed anti-adhesive activity against H. pylori. The anti-adhesive activity of rice bran protein hydrolysate (RPH) was 43.74 ± 1.12% (4 mg mL-1), and gastric digestion (RPHA) had no significant effect on its activity. Hydrophobic amino acids and aromatic amino acids were important for its anti-adhesive activity. Further, 284 peptide sequences with potential anti-adhesive activity were isolated and identified from RPHA. Combined with molecular docking results, four novel anti-adhesive activity peptides were finally screened, namely LS5 (LSFRL), SN8 (SNTPGMVY), VV7 (VVNFGNL) and PV9 (PVLWGVPKG). Among them, PV9 showed the highest anti-adhesive activity of 59.64 ± 2.00% (4 mg mL-1). These four peptides could bind H. pylori adhesins BabA and SabA, occupying the binding sites of cell receptors and acting as anti-adhesion agents. In conclusion, four rice bran protein-derived anti-adhesive activity peptides against H. pylori can be used for the development of novel functional foods antagonizing H. pylori infection.

Tapping into Nature's Arsenal: Harnessing the Potential of Natural Antioxidants for Human Health and Disease Prevention

Numerous natural antioxidants commonly found in our daily diet have demonstrated significant benefits for human health and various diseases by counteracting the impact of reactive oxygen and nitrogen species. Their chemical properties enable a range of biological actions, including antihypertensive, antimicrobial, anti-inflammatory, anti-fibrotic, and anticancer effects. Despite promising outcomes from preclinical studies, ongoing debate persists regarding their reproducibility in human clinical models. This controversy largely stems from a lack of understanding of the pharmacokinetic properties of these compounds, coupled with the predominant focus on monotherapies in research, neglecting potential synergistic effects arising from combining different antioxidants. This study aims to provide an updated overview of natural antioxidants, operating under the hypothesis that a multitherapeutic approach surpasses monotherapy in efficacy. Additionally, this study underscores the importance of integrating these antioxidants into the daily diet, as they have the potential to prevent the onset and progression of various diseases. To reinforce this perspective, clinical findings pertaining to the treatment and prevention of non-alcoholic fatty liver disease and conditions associated with ischemia and reperfusion phenomena, including myocardial infarction, postoperative atrial fibrillation, and stroke, are presented as key references.

Structurally manipulated antioxidant peptides derived from wheat bran: Preparation and identification

Bioactive peptide's development is facing two challenges in terms of its lower yield and limited understanding of structurally orientated functionality. Therefore, peptides were prepared from wheat bran via a cocktail enzyme for achieving a higher level of hydrophobic amino acids than traditional method. The obtained peptides exhibited great antioxidant activities against H2O2-induced oxidative stress in HepG2 cells. Among them, 91 bioactive peptides were selected through the virtual screening, and their N-terminal and C-terminal contained many hydrophobic amino acids. Then the peptides with capacity to interact with Keap1 were identified by in silico simulation, because Keap1 acts as a sensor of redox insults. The results revealed that peptides DLDW and DLGL demonstrated the highest binding affinities, and a bridge was formed between Asp of DLGL and Arg415 of Klech domain, contributing to interfering Keap1-Nrf2 interaction. These findings implied a potential application of wheat bran peptides as nutraceuticals and health-promoting ingredients.

Sunflower seed-derived bioactive peptides show antioxidant and anti-inflammatory activity: From in silico simulation to the animal model

The evolving field of food technology is increasingly dedicated to developing functional foods. This study explored bioactive peptides from sunflower protein isolate (SPI), obtained from defatted flour, a by-product of the oil processing industry. SPI underwent simulated gastrointestinal digestion and the obtained peptide-enriched fraction (PEF) showed antioxidant properties in vivo, in zebrafish. Among the peptides present in PEF identified by mass spectrometry analysis, we selected those with antioxidant properties by in silico evaluation, considering their capability to interact with Keap1, key protein in the regulation of antioxidant response. The selected peptides were synthesized and evaluated in a cellular model. As a result, DVAMPVPK, VETGVIKPG, TTHTNPPPEAE, LTHPQHQQQGPSTG and PADVTPEEKPEV activated Keap1/Nrf2 pathway leading to Antioxidant Response Element-regulated enzymes upregulation. Since the crosstalk between Nrf2 and NF-κB is well known, the potential anti-inflammatory activity of the peptides was assessed and principally PADVTPEEKPEV showed good features both as antioxidant and anti-inflammatory molecule.

From microbes to molecules: a review of microbial-driven antioxidant peptide generation

Oxidative stress, arising from excess reactive oxygen species (ROS) or insufficient antioxidant defenses, can damage cellular components, such as lipids, proteins, and nucleic acids, resulting in cellular dysfunction. The relationship between oxidative stress and various health disorders has prompted investigations into potent antioxidants that counteract ROS's detrimental impacts. In this context, antioxidant peptides, composed of two to twenty amino acids, have emerged as a unique group of antioxidants and have found applications in food, nutraceuticals, and pharmaceuticals. Antioxidant peptides are sourced from natural ingredients, mainly proteins derived from foods like milk, eggs, meat, fish, and plants. These peptides can be freed from their precursor proteins through enzymatic hydrolysis, fermentation, or gastrointestinal digestion. Previously published studies focused on the origin and production methods of antioxidant peptides, describing their structure-activity relationship and the mechanisms of food-derived antioxidant peptides. Yet, the role of microorganisms hasn't been sufficiently explored, even though the production of antioxidant peptides frequently employs a variety of microorganisms, such as bacteria, fungi, and yeasts, which are recognized for producing specific proteases. This review aims to provide a comprehensive overview of microorganisms and their proteases participating in enzymatic hydrolysis and microbial fermentation to produce antioxidant peptides. This review also covers endogenous peptides originating from microorganisms. The information obtained from this review might guide the discovery of novel organisms adept at generating antioxidant peptides.

Novel and efficient techniques in the discovery of antioxidant peptides

As a research hotspot in food science and nutrition, antioxidant peptides can function by scavenging free radicals, inhibiting peroxides, and chelating metal ions. Therefore, how to efficiently discover and screen antioxidant peptides has become a key issue in research and production. Traditional discovery methods are time-consuming and costly, but also challenging to resolve the quantitative structure-activity relationship of antioxidant peptides. Several novel techniques, including artificial intelligence, molecular docking, bioinformatics, quantum chemistry, phage display, switchSENSE, surface plasmon resonance, and fluorescence polarization, are emerging rapidly as solutions. These techniques possess efficient capability for the discovery of antioxidant peptides, even with the potential for high-throughput screening. In addition, the quantitative structure-activity relationship can be resolved. Notably, combining these novel techniques can overcome the drawbacks of a single one, thus improving efficiency and expanding the discovery horizon. This review has summarized eight novel and efficient techniques for discovering antioxidant peptides and the combination of techniques. This review aims to provide scientific evidence and perspectives for antioxidant peptide research.