Influence of molecular weight of chemically sulfated citrus pectin fractions on their antithrombotic and bleeding effects

SummaryEvaluated were the anticoagulant and antithrombotic activities, and bleeding effect of two chemically sulfated polysaccharides, obtained from citric pectin, with different average molar masses. Both low-molecular-weight (Pec-LWS, 3,600 g/mol) and high-molecular-weight sulfated pectins (Pec-HWS, 12,000 g/mol) had essentially the same structure, consisting of a (1→4)-linked α-D-GalpA chain with almost all its HO-2 and HO-3 groups substituted by sulfate. Both polysaccharides had anticoagulant activity in vitro, although Pec-HWS was a more potent anti-thrombotic agent in vivo, giving rise to total inhibition of venous thrombosis at a dose of 3.5 mg/kg body weight. Surprisingly, in contrast with heparin, Pec-HWS and Pec-LWS are able to directly inhibit α-thrombin and factor Xa by a mechanism independent of antithrombin (AT) and/or heparin co-factor II (HCII). Moreover, Pec-HWS provided a lower risk of bleeding than heparin at a dose of 100% effectiveness against venous thrombosis, indicating it to be a promising antithrombotic agent.

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INFLUENCE OF THE SULFATION PATTERN ON CERTAIN BIOLOGICAL PROPERTIES OF GALACTOSAMINOGLYCANS

10.1055/s-0038-1643251 ◽

1987 ◽

Author(s):

B Casu ◽

L Marchese ◽

A Naggi ◽

G Torri ◽

J Fareed ◽

...

Keyword(s):

Molecular Weight ◽

Dermatan Sulfate ◽

Anticoagulant Activity ◽

Chlorosulfonic Acid ◽

Biological Properties ◽

Sulfated Polysaccharides ◽

Low Molecular Weight ◽

Antithrombotic Activity

In order to investigate the influence of charge distribution and chain length on the biological properties of sulfated polysaccharides, additional sulfate groups were introduced into the galactosaminoglycans, chondriotin sulfate and dermatan sulfate. Using a flexible method (with sulfuric acid and chlorosulfonic acid) for concurrent sulfation and controlled depolymerization, numerous products were obtained and characterized by chemical, enzymatic and nuclear magnetic resonance spectroscopic methods. The biologic actions of these products were profiled in both in vitro and in vivo assays for antithrombotic activity. Despite a weaker in vitro anticoagulant activity, low molecular weight over sulfated galactosaminoglycans produced significant dose-dependent antithrombotic actions in animal models which were similar to the actions observed with oversulfated low molecular weight heparins. These results suggest that a significant antithrombotic activity can be elicited through non-specific interactions of polysulfates with cellular and plasma components, and that clusters of sulfate groups such as the 4-6 disulfate group on D-galactosaminoglycan residues may be important for these interactions. Furthermore, these results, also suggest that supersulfation of glycosaminogly-cans results in products with biologic activity distinct from the native material.

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The Anticoagulant Properties of a Modified Form of Protein S

Thrombosis and Haemostasis ◽

10.1055/s-0038-1647048 ◽

1988 ◽

Vol 60 (02) ◽

pp. 298-304 ◽

Cited By ~ 17

Author(s):

C A Mitchell ◽

S M Kelemen ◽

H H Salem

Keyword(s):

Monoclonal Antibody ◽

Anticoagulant Activity ◽

Activated Protein C ◽

Factor Xa ◽

Protein S ◽

Human Neutrophil Elastase ◽

Factor X ◽

Sds Page

SummaryProtein S (PS) is a vitamin K-dependent anticoagulant that acts as a cofactor to activated protein C (APC). To date PS has not been shown to possess anticoagulant activity in the absence of APC.In this study, we have developed monoclonal antibody to protein S and used to purify the protein to homogeneity from plasma. Affinity purified protein S (PSM), although identical to the conventionally purified protein as judged by SDS-PAGE, had significant anticoagulant activity in the absence of APC when measured in a factor Xa recalcification time. Using SDS-PAGE we have demonstrated that prothrombin cleavage by factor X awas inhibited in the presence of PSM. Kinetic analysis of the reaction revealed that PSM competitively inhibited factor X amediated cleavage of prothrombin. PS preincubated with the monoclonal antibody, acquired similar anticoagulant properties. These results suggest that the interaction of the monoclonal antibody with PS results in an alteration in the protein exposing sites that mediate the observed anticoagulant effect. Support that the protein was altered was derived from the observation that PSM was eight fold more sensitive to cleavage by thrombin and human neutrophil elastase than conventionally purified protein S.These observations suggest that PS can be modified in vitro to a protein with APC-independent anticoagulant activity and raise the possibility that a similar alteration could occur in vivo through the binding protein S to a cellular or plasma protein.

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Toxicity of Heparinoids, with Special Reference to the Precipitation of Fibrinogen

Thrombosis and Haemostasis ◽

10.1055/s-0038-1655587 ◽

1964 ◽

Vol 12 (01) ◽

pp. 232-261 ◽

Cited By ~ 2

Author(s):

S Sasaki ◽

T Takemoto ◽

S Oka

Keyword(s):

Molecular Weight ◽

Dextran Sulfate ◽

Anticoagulant Activity ◽

Molecular Structures ◽

Severe Reaction ◽

Clinical Use ◽

Molecular Weights ◽

Close Relationship

SummaryTo demonstrate whether the intravascular precipitation of fibrinogen is responsible for the toxicity of heparinoid, the relation between the toxicity of heparinoid in vivo and the precipitation of fibrinogen in vitro was investigated, using dextran sulfate of various molecular weights and various heparinoids.1. There are close relationships between the molecular weight of dextran sulfate, its toxicity, and the quantity of fibrinogen precipitated.2. The close relationship between the toxicity and the precipitation of fibrinogen found for dextran sulfate holds good for other heparinoids regardless of their molecular structures.3. Histological findings suggest strongly that the pathological changes produced with dextran sulfate are caused primarily by the intravascular precipitates with occlusion of the capillaries.From these facts, it is concluded that the precipitates of fibrinogen with heparinoid may be the cause or at least the major cause of the toxicity of heparinoid.4. The most suitable molecular weight of dextran sulfate for clinical use was found to be 5,300 ~ 6,700, from the maximum value of the product (LD50 · Anticoagulant activity). This product (LD50 · Anticoagulant activity) can be employed generally to assess the comparative merits of various heparinoids.5. Clinical use of the dextran sulfate prepared on this basis gave satisfactory results. No severe reaction was observed. However, two delayed reactions, alopecia and thrombocytopenia, were observed. These two reactions seem to come from the cause other than intravascular precipitation.

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Novel concatameric heparin-binding peptides reverse heparin and low-molecular-weight heparin anticoagulant activities in patient plasma in vitro and in rats in vivo

Blood ◽

10.1182/blood-2003-07-2334 ◽

2004 ◽

Vol 103 (4) ◽

pp. 1356-1363 ◽

Cited By ~ 30

Author(s):

Barbara P. Schick ◽

David Maslow ◽

Adrianna Moshinski ◽

James D. San Antonio

Keyword(s):

Molecular Weight ◽

Low Molecular Weight Heparin ◽

Tandem Repeats ◽

Factor Xa ◽

Low Molecular Weight ◽

Heparin Binding ◽

High Affinity ◽

Binding Peptides

Abstract Patients given unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH) for prophylaxis or treatment of thrombosis sometimes suffer serious bleeding. We showed previously that peptides containing 3 or more tandem repeats of heparin-binding consensus sequences have high affinity for LMWH and neutralize LMWH (enoxaparin) in vivo in rats and in vitro in citrate. We have now modified the (ARKKAAKA)n tandem repeat peptides by cyclization or by inclusion of hydrophobic tails or cysteines to promote multimerization. These peptides exhibit high-affinity binding to LMWH (dissociation constant [Kd], ≈ 50 nM), similar potencies in neutralizing anti–Factor Xa activity of UFH and enoxaparin added to normal plasma in vitro, and efficacy equivalent to or greater than protamine. Peptide (ARKKAAKA)3VLVLVLVL was most effective in all plasmas from enoxaparin-treated patients, and was 4- to 20-fold more effective than protamine. Several other peptide structures were effective in some patients' plasmas. All high-affinity peptides reversed inhibition of thrombin-induced clot formation by UFH. These peptides (1 mg/300 g rat) neutralized 1 U/mL anti–Factor Xa activity of enoxaparin in rats within 1 to 2 minutes. Direct blood pressure and heart rate measurements showed little or no hemodynamic effect. These heparin-binding peptides, singly or in combination, are potential candidates for clinical reversal of UFH and LMWH in humans.

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In vitro and in vivo studies of the novel antithrombotic agent BAY 59-7939-an oral, direct Factor Xa inhibitor

Journal of Thrombosis and Haemostasis ◽

10.1111/j.1538-7836.2005.01166.x ◽

2005 ◽

Vol 3 (3) ◽

pp. 514-521 ◽

Cited By ~ 399

Author(s):

E. PERZBORN ◽

J. STRASSBURGER ◽

A. WILMEN ◽

J. POHLMANN ◽

S. ROEHRIG ◽

...

Keyword(s):

Factor Xa ◽

In Vivo Studies ◽

Factor Xa Inhibitor ◽

The Novel ◽

Direct Factor ◽

Antithrombotic Agent

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Anticoagulant Properties of a Green Algal Rhamnan-type Sulfated Polysaccharide and Its Low-molecular-weight Fragments Prepared by Mild Acid Degradation

Marine Drugs ◽

10.3390/md16110445 ◽

2018 ◽

Vol 16 (11) ◽

pp. 445 ◽

Cited By ~ 7

Author(s):

Xue Liu ◽

Peng Du ◽

Xiao Liu ◽

Sujian Cao ◽

Ling Qin ◽

...

Keyword(s):

Molecular Weight ◽

Anticoagulant Activity ◽

Sulfated Polysaccharide ◽

Low Molecular Weight ◽

Thrombin Time ◽

Acid Degradation ◽

Molecular Weights ◽

Green Algal

The active sulfated polysaccharide from seaweed possesses important pharmaceutical and biomedical potential. In the study, Monostroma sulfated polysaccharide (MSP) was obtained from Monostroma angicava, and the low-molecular-weight fragments of MSP (MSP-Fs: MSP-F1–MSP-F6) were prepared by controlled acid degradation. The molecular weights of MSP and MSP-F1–MSP-F6 were 335 kDa, 240 kDa, 90 kDa, 40 kDa, 24 kDa, 12 kDa, and 6.8 kDa, respectively. The polysaccharides were sulfated rhamnans that consisted of →3)-α-l-Rhap-(1→ and →2)-α-l-Rhap-(1→ units with partial sulfation at C-2 of →3)-α-l-Rhap-(1→ and C-3 of →2)-α-l-Rhap-(1→. Anticoagulant properties in vitro of MSP and MSP-F1–MSP-F6 were evaluated by studying the activated partial thromboplastin time, thrombin time, and prothrombin time. Anticoagulant activities in vivo of MSP and MSP-F4 were further evaluated; their fibrin(ogen)olytic activities in vivo and thrombolytic properties in vitro were also assessed by D-dimer, fibrin degradation products, plasminogen activator inhibitior-1, and clot lytic rate assays. The results showed that MSP and MSP-F1–MSP-F4 with molecular weights of 24–240 kDa had strong anticoagulant activities. A decrease in the molecular weight of MSP-Fs was accompanied by a decrease in the anticoagulant activity, and higher anticoagulant activity requires a molecular weight of over 12 kDa. MSP and MSP-F4 possessed strong anticoagulant activities in vivo, as well as high fibrin(ogen)olytic and thrombolytic activities. MSP and MSP-F4 have potential as drug or helpful food supplements for human health.

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Effect ofToona microcarpaHarms Leaf Extract on the Coagulation System

BioMed Research International ◽

10.1155/2014/615363 ◽

2014 ◽

Vol 2014 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Hao Chen ◽

Min Jin ◽

Yi-Fen Wang ◽

Yong-Qing Wang ◽

Ling Meng ◽

...

Keyword(s):

Leaf Extract ◽

Factor Xa ◽

Adenosine Diphosphate ◽

Coagulation System ◽

Dependent Manner ◽

Thrombin Time ◽

Antithrombotic Agent ◽

Thrombin Activity

Toona microcarpaHarms is a tonic, antiperiodic, antirheumatic, and antithrombotic agent in China and India and an astringent and tonic for treating diarrhea, dysentery, and other intestinal infections in Indonesia. In this study, we prepared ethyl-acetate extract from the air-dried leaves ofToona microcarpaHarms and investigated the anticoagulant activitiesin vitroby performing activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT) assays. Antiplatelet aggregation activity of the extract was examined using adenosine diphosphate (ADP), collagen, and thrombin as agonists, and the inhibitions of factor Xa and thrombin were also investigated. Bleeding and clotting times in mice were used to determine its anticoagulant activitiesin vivo. It is found thatToona microcarpaHarms leaf extract (TMHE) prolonged APTT, PT, and TT clotting times in a dose-dependent manner and significantly inhibited platelet aggregation induced by thrombin, but not ADP or collagen. Clotting time and bleeding time assays showed that TMHE significantly prolonged clotting and bleeding timesin vivo. In addition, at the concentration of 1 mg/mL, TMHE inhibited human thrombin activity by 73.98 ± 2.78%. This is the first report to demonstrate that THME exhibits potent anticoagulant effects, possibly via inhibition of thrombin activity.

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A Comparison of Anticoagulation Activity of a Potent Heparin Preparation in Different Test

10.1055/s-0039-1687438 ◽

1979 ◽

Author(s):

A.S. Bhargava ◽

J. Heinick ◽

Chr. Schöbel ◽

P. Günzel

Keyword(s):

Blood Clotting ◽

Anticoagulant Activity ◽

Factor Xa ◽

Thrombin Time ◽

Beagle Dogs ◽

Clotting Time ◽

Relative Potencies ◽

Heparin Preparation

The anticoagulant effect of a new potent heparin preparation was compared with a commercially available heparin in vivo after intravenous application in beagle dogs. The anticoagulant activity was determined using thrombin time, activated partial thromboplastin time and whole blood clotting time after 5, 10 and 30 minutes of application. The relative potency of the new heparin preparation (Scherinq) was found to be 1.62 to 2.52 times higher than heparin used for comparison (150 USP units/mg, Dio-synth). The anticoagulant properties of both preparations were also studied in vitro using dog and human plasma. The relative potencies in vitro correlated well with those obtained in vivo. Further characterization with amidolytic method using chromogenic substrate for factor Xa and thrombin (S-2222 and S-2238 from KABI, Stockholm) showed that heparin (Schering) contains 243 to 378 USP units/raq depending upon the test systems used to assay the anticoagulation activity and in addition, proves the validity of the amidolytic method.

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Novel Design of Peptides to Reverse the Anticoagulant Activities of Heparin and other Glycosaminoglycans

Thrombosis and Haemostasis ◽

10.1055/s-0037-1615609 ◽

2001 ◽

Vol 85 (03) ◽

pp. 482-487 ◽

Cited By ~ 15

Author(s):

Joel Gradowski ◽

James San Antonio ◽

Jose Martinez ◽

Barbara Schick

Keyword(s):

Molecular Weight ◽

Unfractionated Heparin ◽

Low Molecular Weight Heparin ◽

Factor Xa ◽

Low Molecular Weight ◽

Heparin Binding ◽

Antifactor Xa ◽

Novel Design

SummaryPatients undergoing anticoagulation with unfractionated heparin, low molecular weight heparin, or danaparoid may experience excess bleeding which requires reversal of the anticoagulant agent. Protamine is at present the only agent available for reversal of unfractionated heparin. Protamine is not effective in patients who have received low molecular weight heparin or danaparoid. We have developed a series of peptides based on consensus heparin binding sequences (Verrecchio et al., J Biol Chem 2000; 275: 7701-7707) that are capable of neutralizing the anti-thrombin activity of unfractionated heparin in vitro, the antifactor Xa activity of unfractionated heparin, Enoxaparin (Lovenox) and danaparoid (Orgaran) in vitro and the anti-Factor Xa activity of Enoxaparin in vivo in rats. These peptides may serve as alternatives for Protamine reversal of UFH and may be useful for neutralization of enoxaparin and danaparoid in humans.

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In Vitro Evaluation of Apixaban, a Novel, Potent, Selective and Orally Bioavailable Factor Xa Inhibitor.

Blood ◽

10.1182/blood.v108.11.4130.4130 ◽

2006 ◽

Vol 108 (11) ◽

pp. 4130-4130 ◽

Cited By ~ 13

Author(s):

Joseph M. Luettgen ◽

Tracy A. Bozarth ◽

Jeffrey M. Bozarth ◽

Frank A. Barbera ◽

Patrick Y. Lam ◽

...

Keyword(s):

Human Plasma ◽

Serine Proteases ◽

Anticoagulant Activity ◽

Factor Xa ◽

Coagulation Factor ◽

Competitive Inhibitor ◽

Rat Plasma ◽

Reversible Inhibitor ◽

Antithrombotic Agent

Abstract Apixaban, previously known as BMS-562247, is a high affinity, highly selective, orally-active, reversible inhibitor of coagulation factor Xa (fXa), in clinical studies as a therapeutic agent for prevention and treatment of thromboembolic diseases. The in vitro characteristics of apixaban were evaluated in purified systems and in human blood from healthy volunteers. Detailed kinetic analysis of apixaban inhibition of human fXa showed that it is a readily reversible, potent and competitive inhibitor versus a synthetic tripeptide substrate with a Ki of 0.08 nM, an association rate of 2 × 107 M−1s−1and a dissociation half life of 3.4 min. Weak affinity (Ki ~3 μM) is observed for thrombin, plasma kallikrein, and chymotrypsin. Affinity for trypsin and all other serine proteases tested is negligible with Ki > 15 μM. Apixaban is an effective inhibitor of free fXa and of prothrombinase, in buffer, platelet poor plasma, and whole blood. The anticoagulant activity of apixaban was determined in platelet-poor human plasma. Apixaban causes concentration dependent prolongation of the fXa mediated clotting assays. The human plasma concentration required to produce a doubling of the clotting time is 3.6 μM for prothrombin time, 7.4 μM for activated partial thromboplastin time and 0.4 μM for HepTest. To support preclinical efficacy and safety studies purified fXa from rabbit, dog and rat plasma was also found to be inhibited by apixaban (0.17, 2.6, and 1.3 nM, respectively). In summary the in vitro properties of apixaban show that it is a highly selective and potentially potent antithrombotic agent for venous and arterial thrombotic diseases.

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