Experimental Protocols Used to Mimic Gastrointestinal Protein Digestion: A Systematic Review.

Bioactive peptides derived from native proteins modulate physiological processes in the metabolic pathways. Given that multiple protocols in the literature mimic the digestion of dietary components, gathering studies that use such models directed at protein digestion processes is critical. This systematic review aimed to gather evidence that adopted adequate experimental models to simulate human protein digestion. The databases searched were PubMed, Web of Science, ScienceDirect, Embase, Virtual Health Library, and Scopus. A total of 1985 articles were found, resulting in 20 eligible in vitro studies. The Office of Health Assessment and Translation was used to evaluate methodological quality. Seven studies used plant-based protein sources, twelve used animal protein sources, and one used both. The duration of the oral phase varied, although 60% of the studies employed a protein digestion period of 120 min. Amylase, pepsin, and pancreatin enzymes were utilized in 40% of the studies, with pH levels of 7, 3, and 7, respectively, during the oral, gastric, and intestinal phases. The INFOGEST harmonized static model was adopted by 65% of the studies; INFOGEST is the most effective model for simulating gastrointestinal protein processes in humans and can be used to answer several research questions because it describes experimental conditions close to the human physiological situation.

Prospecting native and analogous peptides with anti-SARS-CoV-2 potential derived from the trypsin inhibitor purified from tamarind seeds.

The study aimed to prospect in silico native and analogous peptides with anti-SARS-CoV-2 potential derived from the trypsin inhibitor purified from tamarind seeds (TTIp). From the most stable theoretical model of TTIp (TTIp 56/287), in silico cleavage was performed for the theoretical identification of native peptides and generation of analogous peptides. The anti-SARS-CoV-2 potential was investigated through molecular dynamics (MD) simulation between the peptides and binding sites of transmembrane serine protease 2 (TMPRSS2), responsible for the entry of SARS-CoV-2 into the host cell. Five native and analogous peptides were obtained and validated through chemical and physical parameters. The best interaction potential energy (IPE) occurred between TMPRSS2 and one of the native peptides obtained by cleavage with trypsin and its analogous peptide. Thus, both peptides showed many hydrophobic residues, a common physical-chemical property among the peptides that inhibit the entry of enveloped viruses, such as SARS-CoV-2, present in specific drugs to treat COVID-19.

Hydrolyzed Proteins and Vegetable Peptides: Anti-Inflammatory Mechanisms in Obesity and Potential Therapeutic Targets.

Chronic low-grade inflammation is present in overweight and obesity, causing changes in several metabolic pathways. It impairs systemic functioning and positively feeds back the accumulation of more adipose tissue. Studies with hydrolyzed proteins and plant peptides have demonstrated a potential anti-inflammatory and immunomodulatory effect of these peptides. However, it is challenging and necessary to explore the mechanism of action of such molecules because understanding their effects depends on their structural characterizations. Furthermore, the structure might also give insights into safety, efficacy and efficiency, with a view of a possible health application. Thus, the present narrative review aimed to discuss the mechanisms of action of hydrolyzed proteins and plant peptides as anti-inflammatory agents in obesity. Keywords and related terms were inserted into databases for the search. Based on the studies evaluated, these biomolecules act by different pathways, favoring the reduction of inflammatory cytokines and adipokines and the polarization of macrophages to the M2 phenotype. Finally, as a future perspective, bioinformatics is suggested as a tool to help understand and better use these molecules considering their applicability in pre-clinical and clinical studies.

What are the mechanisms of action of anti-inflammatory agents in adipose tissue?: A protocol for systematic review and meta-analysis.

BACKGROUND: Obesity is a disease characterized by the abnormal accumulation of adipose tissue in the body, triggering a chronic subclinical state of inflammation. Bioactive compounds, given their anti-inflammatory properties, are a safe and promising alternative in controlling the inflammatory condition of obesity. This study describes a systematic review protocol aiming to analyze the anti-inflammatory molecules mechanisms and compounds action on adipocytes. METHODS: Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) will outline the protocol and PRISMA to the systematic review. The databases used for research will be PubMed, Science Direct, Scopus, Web of Science, BVS, and EMBASE. Experimental studies performed on rats and mice with a control group that describes treatment with anti-inflammatory agents (drugs, nutraceuticals, bio active compounds, among others) at any frequency, time, and dose will be included. Three independent reviewers will select studies and extract data. The evaluation of the methodological quality of each research will be performed using the SYRCLE tool. If at least 2 studies show clinical and/or methodological and/or statistical homogeneity, a meta-analysis will be performed, using the RevMan Analyzes statistical package in Review Manager v.5.3. RESULTS: In this study, we hope to find a considerable number of articles presenting mechanisms involved in the action of anti-inflammatory molecules and compounds on adipocytes. CONCLUSION: The systematic review produced from this protocol will present evidence on the mechanisms involved in the action of anti-inflammatory molecules and compounds in adipocytes. It will also contribute to developing new research and new insights about anti-inflammatory therapies with a future application view. RECORD OF SYSTEMATIC REVIEW: This review was registered with the International Register of Prospective Systematic Reviews on May 18, 2020 (registration: CRD42020182897). Available at: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020182897.

Structural insights and molecular dynamics into the inhibitory mechanism of a Kunitz-type trypsin inhibitor from Tamarindus indica L.

Trypsin inhibitors from tamarind seed have been studied in vitro and in preclinical studies for the treatment of obesity, its complications and associated comorbidities. It is still necessary to fully understand the structure and behaviour of these molecules. We purifed this inhibitor, sequenced de novo by MALDI-TOF/TOF, performed its homology modelling, and assessed the interaction with the trypsin enzyme through molecular dynamics (MD) simulation under physiological conditions. We identified additional 75 amino acid residues, reaching approximately 72% of total coverage. The four best conformations of the best homology modelling were submitted to the MD. The conformation n°287 was selected considering the RMSD analysis and interaction energy (-301.0128 kcal.mol-1). Residues Ile (54), Pro (57), Arg (59), Arg (63), and Glu (78) of pTTI presented the highest interactions with trypsin, and arginine residues were mainly involved in its binding mechanism. The results favour bioprospecting of this protein for pharmaceutical health applications.