SSGE and DEE, new peptides isolated from a soy protein hydrolysate that inhibit platelet aggregation

Targeted release of soybean peptide from CMC/PVA hydrogels in simulated intestinal fluid and their pharmacokinetics

Carboxymethyl cellulose (CMC)/polyvinyl alcohol (PVA) hydrogels loaded with soybean peptide (SPE) were fabricated via a freeze-thaw method. These hydrogels conquer barriers in simulated gastric fluid (SGF), and then release SPE in simulated intestinal fluid (SIF). The results of in vitro SPE release from these hydrogels showed that in SGF only a little of the SPE released, but in SIF the SPE was completely released. The released SPE had scavenging rates for DPPH and ABTS free radicals of 41.68 and 31.43 %. The pharmacokinetic model of SPE release from the hydrogels in SIF was studied. When the hydrogels are moved from SGF to SIF, the sorption of the shrinkage hydrogel network is entirely controlled by stress-induced relaxations. There are swollen and shrunken regions during SPE release. For SPE release into the SIF, SPE has to be freed from the weak bonds in the swollen regions by changes in the conformation of CMC and PVA. The release rate of SPE was found to be governed by the diffusion and swelling rate of the shrinkage hydrogel network. The Korsmeyer-Peppas equation diffusion exponents (n) for SPE release from the hydrogels are >2.063, indicating a super case II transport. These data demonstrate CMC/PVA hydrogels have potential applications in oral peptide delivery.

Novel Peptide Motifs Containing Asp-Glu-Gly Target P2Y12 and Thromboxane A2 Receptors to Inhibit Platelet Aggregation and Thrombus Formation

Increasing evidence has shown that collagen peptides have multiple biological activities. Our previous study has separated and identified antiplatelet aggregation peptides Asp-Glu-Gly-Pro (DEGP) from Salmo salar skin. This study is to investigate the cellular target of DEGP on platelets and its underlying mechanism. DEGP inhibited platelet aggregation in a dose-dependent manner induced by 2MeS-ADP and U46619 and significantly attenuated tail thrombosis formation by 30% in mice at the dose of 50 mg/kg body weight. Mechanically, DEGP displayed apparent antagonism effects on TP and P₂Y₁₂ receptors by the drug affinity responsive target stability (DARTS) technique to regulate the phosphorylation of RhoA^S188, PLCβ3^S537, as well as VASP^S157. The molecular docking results revealed a stronger binding energy with the target protein of modified peptides DEGI and DDEGL. Practically, DEGI exhibited the highest inhibition activity against 2MeS-ADP- and U46619-induced platelet aggregation in vitro with IC₅₀ values of 0.88 ± 0.10 and 0.85 ± 0.10 mM, respectively, and comparable antithrombosis activity with aspirin at the dose of 25 mg/kg body weight in vivo. These results indicated the possibility that the peptide motifs containing Asp-Glu-Gly could potentially be developed as a novel therapeutic agent in the prevention and treatment of thrombotic diseases.

Novel Hyp-Gly-containing antiplatelet peptides from collagen hydrolysate after simulated gastrointestinal digestion and intestinal absorption

Bioactive components causing the antiplatelet activity upon collagen hydrolysate (CH) ingestion have not been clarified yet. This study aimed to identify antiplatelet peptides from CH after simulated gastrointestinal digestion and intestinal absorption. Four antiplatelet peptides containing the Hyp-Gly (OG) sequence including OG, Hyp-Gly-Glu (OGE), Pro-Gly-Glu-Hyp-Gly (PGEOG) and Val-Gly-Pro-Hyp-Gly-Pro-Ala (VGPOGPA) were successfully identified. All four peptides exhibited antiplatelet activity, but OGE and PGEOG exerted stronger activity than OG and VGPOGPA. The IC50 value of OGE and PGEOG was 1.076 mM and 1.167 mM, respectively. These four antiplatelet peptides could survive simulated gastrointestinal digestion and be absorbed intact by Caco-2 cells. Furthermore, plasma stability experiments showed that OG and OGE showed a good stability in human plasma, but PGEOG and VGPOGPA showed a relatively poor stability. In vivo studies indicated that OG and OGE were present in blood after the oral administration of CH. Meanwhile, OGE exerted significant in vivo anti-thrombotic activity after its ingestion. The present study clarifies the antiplatelet components causing the CH activity and highlights the potential application of CH or these four peptides as functional foods to combat thrombosis by inhibiting platelet aggregation.

Membrane-based preparative methods and bioactivities mapping of tempe-based peptides

This study was aimed to produce bioactive peptides from optimally fermented tempe, and map their overall bioactivities. There were three preparative methods utilized for producing tempe-based peptides, such as water-facilitated extraction, alcalase, and papain hydrolysis, and in combination with membrane filtration. Fermenting soybean at 144 h was selected as the optimum time based on protein content and degree of hydrolysis. Through SDS-PAGE analysis, an increased degree of hydrolysis with longer fermentation time was confirmed. The best preparative method for producing bioactive peptides was through papain hydrolysis and followed by 5 kDa membrane filtration. By this, the enhancement was distinct for antioxidant activity, ACE-, α-glucosidase-, and Kunitz trypsin-inhibitory activity. The annotated peptide sequences resulting from Nano LC Ultimate 3000 Series System tandem Q Exactive™ Hybrid Quadrupole-Orbitrap™ Mass Spectrometer were matched with the BIOPEP database. The major bioactivities of tempe peptides obtained were as an ACE inhibitor, antioxidant, and antithrombotic.

Purification and Characterization of Novel Collagen Peptides against Platelet Aggregation and Thrombosis from Salmo salar

Collagen is a rich source of bioactive peptides and is widely distributed in the skin and bone tissue. In this study, collagen from Salmo salar skin was hydrolyzed with Alcalase or Protamex followed by simulated digestion, YMC ODS-A C18 separation, and ESI-MS/MS analysis. A total of 19 peptides were identified and synthesized for investigation of their antiplatelet activities. Hyp-Gly-Glu-Phe-Gly (OGEFG) and Asp-Glu-Gly-Pro (DEGP) exhibited the most potent activity against ADP-induced platelet aggregation among them with IC₅₀ values of 277.17 and 290.00 μM, respectively, and inhibited the release of β-TG and 5-HT in a dose-dependent manner significantly. Single oral administration of OGEFG and DEGP also inhibited thrombus formation in a ferric chloride-induced arterial thrombosis model at a dose of 200 μmol/kg body weight and did not prolong the bleeding time or cause an immune response in mice. Therefore, our findings indicated that collagen peptides had a potential to be developed into an effective specific medical food in the prevention of thrombotic diseases.

The in vitro bioavailability of anti-platelet peptides in collagen hydrolysate from silver carp (Hypophthalmichthys molitrix) skin

Previous animal experiments indicated collagen hydrolysates (CHs) intake decreased platelet release indicators in plasma and highlight potential applications as healthcare supplements to combat cardiovascular disease. The oligopeptides (GPR, GPRG, and GPRGP) have anti-platelet activities. However, it is still unclear whether they are bioactive compounds in CHs from silver carp skin. We investigated the bioavailability of oligopeptides using simulated gastrointestinal digestion and Caco-2 model. Anti-thrombotic activities, in vitro platelet aggregation and formation of platelet thrombus, were evaluated. They resisted gastrointestinal digestion and could be absorbed by Caco-2. Oligopeptides inhibited platelet aggregation induced by adenosine diphosphate and thrombin with IC₅₀ of 0.160, 0.283, 0.251 mg/ml and 0.714, 1.008, 0.917 mg/ml for GPR, GPRG, and GPRGP, respectively. Oligopeptides prolonged the time of platelet thrombus and inhibited coagulation cascades, but CHs performed no bleeding side effect. These results confirmed that oligopeptides could be used as bioactive compounds of dietary supplements for pre-thrombotic to prevent thrombosis. PRACTICAL APPLICATIONS: Oligopeptides, GPR, GPRG, and GPRGP, derived from silver carp (Hypophthalmichthys molitrix) skin collagen, performed anti-thrombotic activities from their anti-platelet aggregation and anticoagulation activities. But the collagen hydrolysates containing these peptides had no side effect of bleeding in the mice model. Furthermore, this study investigated the bioavailability of these three bioactive peptides by the Caco-2 cells model. Thus, oligopeptides GPR, GPRG, and GPRGP are a potential index of bioactive compounds in the preparation of anti-thrombotic functional foods or healthcare supplements for people at the pre-thrombotic state.

Protein Hydrolysates and Biopeptides: Production, Biological Activities, and Applications in Foods and Health Benefits. A Review

In recent years, a great deal of interest has been expressed regarding the production, characterization, and applications of protein hydrolysates and food-derived biopeptides due to their numerous beneficial health effects. In this regard, research is mainly focused on investigating the therapeutic potential of these natural compounds. Based on their amino acids composition, sequences, hydrophobicity, and length, peptides released from food proteins, beyond their nutritional properties, can exhibit various biological activities including antihypertensive, antioxidative, antithrombotic, hypoglycemic, hypocholesterolemic, and antibacterial activities among others. Protein hydrolysates are essentially produced by enzymatic hydrolysis of whole protein sources by appropriate proteolytic enzymes under controlled conditions, followed by posthydrolysis processing to isolate desired and potent bioactive peptides from a complex mixture of active and inactive peptides. Therefore, because of their human health potential and safety profiles, protein hydrolysates and biopeptides may be used as ingredients in functional foods and pharmaceuticals to improve human health and prevent diseases. In this review, we have focused on the major variables influencing the enzymatic process of protein hydrolysates production. The biological properties of protein hydrolysates will be described as well as their applications in foods and health benefits.

Antithrombotic and Antioxidant Activity of Amaranth Hydrolysate Obtained by Activation of an Endogenous Protease

Ingestion of diets with antithrombotic and antioxidant components offer a convenient and effective way to prevent and reduce the incidence of cardiovascular diseases. The aim of the present work was to obtain an amaranth hydrolysate by the activation of an endogenous aspartic protease, to establish adequate experimental conditions, and to evaluate its antithrombotic and antioxidant activity in order to assess its potential application as an ingredient in functional foods. The results obtained not only confirmed the presence of an endogenous protease in the amaranth isolate, but also allowed us to select an adequate incubation conditions (pH 2, 40 °C, 16 h). The hydrolysate obtained (degree of hydrolysis 5.3 ± 0.4 %) showed potential antithrombotic activity (IC50 = 5.9 ± 0.1 mg soluble protein/mL) and had more antioxidant activity than the isolate, indicating that the activation of the protease released bioactive peptides from amaranth proteins. Decreasing the pH is a simple and cheap process and is another way to obtain potential functional ingredients with bioactive compounds.

A novel peptide inhibitor of platelet aggregation from stiff silkworm, Bombyx batryticatus

A novel platelet aggregation inhibitory peptide, named BB octapeptide, was isolated from stiff silkworm (Bombyx batryticatus) by gel filtration, anion-exchange, and reverse-phase high performance liquid chromatography. The molecular mass of the peptide was determined to be 885 Da using electrospray ionization mass spectrometry, and the sequence was identified as Asp-Pro-Asp-Ala-Asp-IIe-Leu-Gln using the Edman degradation method. To test its biological activity, the peptide was chemically synthesized using Fmoc solid-phase synthesis method. BB octapeptide inhibited rabbit platelet aggregation that was induced by collagen and epinephrine, with the IC50 values of 91.14 μM and 104.50 μM, respectively. After intravenous administrated in mice (30 mg/kg, 4 days), BB octapeptide showed similar ex vivo efficacy of inhibiting platelet aggregation as aspirin (10 mg/kg). In addition, this peptide prevented paralysis and death in pulmonary thromboembolism model and significantly reduced ferric chloride-induced thrombus formation in rats. Moreover, it exhibited low cytotoxicity in a cellular model. In conclusion, this is the first report that a novel platelet aggregation inhibitory peptide was isolated from stiff silkworm (B. batryticatus). Due to the excellent efficacy in reducing platelet aggregation and low toxicity, it can be a valuable lead compound for new drug design and development.

Purification and characterization of a novel antithrombotic peptide from Scolopendra subspinipes mutilans

ETHNOPHARMACOLOGICAL RELEVANCE

The centipede has been prescribed for the treatment of cardiovascular diseases in Korea, China and other Far Eastern Asian countries for several hundred years.

MATERIALS AND METHODS

A novel antithrombotic peptide was isolated from Scolopendra subspinipes mutilans using a combination of ultrafiltration, Sephadex G-50 column, Source 15Q anion exchange column and RP-HPLC C18 column.

RESULTS

The molecular mass of the purified peptide is 346Da measured by Electrospray Ionization Mass Spectrometry (ESI-MS). The primary structure of the peptide is Ser-Gln-Leu (SQL) determined by Edman degradation. SQL potently prolonged the activated partial thromboplastin time (aPTT), and inhibited platelet aggregation.

CONCLUSIONS

These results help to clarify the mechanism of the antithrombotic activity of the centipede for effective treatment of cardiovascular and cerebrovascular diseases.

High performance liquid chromatography and capillary electrophoresis in the analysis of soybean proteins and peptides in foodstuffs

The increasing interest in functional and healthy food products has promoted the use of soybean in the manufacture of foods for human consumption. Soybean basic products (soybeans, textured soybean, soybean flour, soybean protein concentrate and soybean protein isolate) as well as soybean derivatives (soybean dairy-like products, soybean drinks with fruits, meat analogues, etc.) are commercially available. In addition, due to the interesting nutritional and functional properties of soybean proteins, they are usually employed as ingredient in the elaboration of a large number of food products such as bakery or meat products among others. In spite of the good characteristics of soybean proteins, their addition to some products is forbidden or allowed up to a certain limit. Therefore, analytical methodologies to achieve the determination of soybean proteins in foods are necessary in order to make possible adequate quality control and to prove that legal regulations controlling their addition are accomplished. However, this is not an easy task due to the diversity and complexity of the food matrices and the technological treatments to which some of these foods are submitted during their elaboration. This article presents for the first time a comprehensive review on the analytical methodologies developed using HPLC and CE to characterize soybeans and to analyse soybean proteins in meals. Moreover, the use of HPLC and CE in the characterization of soybean protein fractions and their hydrolyzates, and a study of their relationships to nutritional, functional and biomedical properties are included. Finally, the application of proteomic methodologies in soybean food technology is also reviewed.

Chromatography of amino acids and short peptides. New advances

The newest results in the application of various chromatographic methods (gas-liquid chromatography, liquid chromatographic techniques, electrically driven systems) for the separation and quantitative determination of amino acids and short peptides in pure state and in complicated matrices are compiled. The results are concisely described and critically evaluated. The future trends of the chromatographic analysis of amino acids and short peptides are briefly discussed.

Isolation and characterization of a novel platelet aggregation inhibitory peptide from the medicinal mushroom, Inonotus obliquus

This study describes the extraction and characterization of a platelet aggregation inhibitory peptide from Inonotus obliquus. Ethanol extract from I. obliquus ASI 74006 mycelia showed the highest platelet aggregation inhibitory activity (81.2%). The maximum platelet aggregation inhibitory activity was found when the mycelia of I. obliquus ASI 74006 was extracted with ethanol at 80 degrees C for 12 h. The platelet aggregation inhibitor was purified by systematic solvent fractionation, ultrafiltration, Sephadex G-10 column chromatography, and reverse-phase HPLC. The purified platelet aggregation inhibitor is a novel tripeptide with a molecular mass of 365 Da, having a sequence of Trp-Gly-Cys. The purified platelet aggregation inhibitor also showed high platelet aggregation inhibitory activity in Institute of Cancer Research (ICR) mice.