Bioassay-directed fractionation of a blood coagulation factor Xa inhibitor, betulinic acid from Lycopus lucidus

AbstractThrombosis is a major cause of morbidity and mortality worldwide and plays a pivotal role in the pathogenesis of several cardiovascular disorders, including acute coronary syndrome, unstable angina, myocardial infarction, sudden cardiac death, peripheral arterial occlusion, ischemic stroke, deep-vein thrombosis, and pulmonary embolism. Anticoagulants, antiplatelet agents, and fibrinolytics can reduce the risks of these clinical events. Especially, the blood coagulation factor Xa (FXa) inhibitor is a proven anticoagulant. Promoting blood circulation, using traditional Chinese medicine (TCM), for the treatment of these diseases has been safely used for thousands of years in clinical practice. Therefore, highly safe and effective anticoagulant ingredients, including FXa inhibitors, could be found in TCM for activating the blood circulation. One FXa inhibitor, a pentacyclic triterpene (compound 1, betulinic acid) characterized by IR, MS and NMR analyses, was isolated from the ethyl acetate fraction of Lycopus lucidus by bioassay-directed fractionation. Compound 1 exhibited an inhibitory effect on FXa with IC50 25.05 μmol/L and reduced the thrombus weight in an animal model at 25-100 mg/kg. These results indicate that betulinic acid could be the potential for anticoagulant therapy.

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RPR120844, a Novel, Specific Inhibitor of Coagulation Factor Xa Inhibits Venous Thrombosis in the Rabbit

Thrombosis and Haemostasis ◽

10.1055/s-0037-1614434 ◽

1999 ◽

Vol 81 (01) ◽

pp. 157-160 ◽

Cited By ~ 14

Author(s):

Ross Bentley ◽

Suzanne Morgan ◽

Karen Brown ◽

Valeria Chu ◽

Richard Ewing ◽

...

Keyword(s):

Jugular Vein ◽

Drug Effect ◽

Ex Vivo ◽

Thrombus Formation ◽

Specific Inhibitor ◽

Factor Xa ◽

Coagulation Factor ◽

Antithrombotic Activity ◽

Fxa Inhibitor

SummaryThe in vivo antithrombotic activity of RPR120844, a novel synthetic coagulation factor Xa (fXa) inhibitor (Ki = 7 nM), was assessed by its ability to inhibit thrombus formation in a damaged segment of the rabbit jugular vein. Intravenous dose-response studies were performed and thrombus mass (TM), activated partial thromboplastin time (APTT), prothrombin time (PT), inhibition of ex vivo fXa activity and plasma drug levels (PDL) were determined. TM, measured at the end of a 50 min infusion, was significantly reduced (p <0.05 vs saline-treated animals) by RPR120844 at 30 and 100 μg/kg/min. At doses of 10, 30 and 100 μg/kg/min, APTT was prolonged by 2.1, 4.2 and 6.1-fold, and PT was prolonged by 1.4, 2.2 and 3.5-fold, respectively. PDL were determined by measuring anti-fXa activity using an amidolytic assay. Peak PDL were 0.8 ± 0.3, 1.5 ± 0.9 and 2.4 ± 0.6 μM, respectively. The drug effect was reversible with APTT, PT and PDL returning toward pretreatment values 30 min after termination of treatment. The results suggest that RPR120844, or similar compounds, may provide an efficacious, yet easily reversible, means of inhibiting thrombus formation.

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Reaction pathway for inhibition of blood coagulation factor Xa by tick anticoagulant peptide

Biochemistry ◽

10.1021/bi00138a019 ◽

1992 ◽

Vol 31 (23) ◽

pp. 5374-5380 ◽

Cited By ~ 41

Author(s):

Susan P. Jordan ◽

Shi Shan Mao ◽

Sidney D. Lewis ◽

Jules A. Shafer

Keyword(s):

Blood Coagulation ◽

Reaction Pathway ◽

Factor Xa ◽

Coagulation Factor ◽

Tick Anticoagulant Peptide

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Rivaroxaban in der Prävention und Therapie thromboembolischer Erkrankungen

Hämostaseologie ◽

10.5482/hamo-12-05-0005 ◽

2012 ◽

Vol 32 (03) ◽

pp. 195-202

Author(s):

T. Helbing ◽

C. Bode ◽

M. Moser

Keyword(s):

Low Dose ◽

Factor Xa ◽

Coagulation Factor ◽

Replacement Surgery ◽

Vein Thrombosis ◽

Hip Replacement Surgery ◽

Coronary Syndrome ◽

Prevention And Treatment ◽

Deep Vein ◽

Routine Coagulation

SummaryRivaroxaban (Xarelto®) is a new anticoagulant for the prevention and treatment of thromboembolic disorders. Rivaroxaban inhibits coagulation factor Xa directly, has high oral bioavailability, shows low propensity for drug-drug interactions and requires no routine coagulation monitoring. In patients undergoing elective knee or hip replacement surgery rivaroxaban (10 mg/d) is highly effective to prevent venous thromboembolism. In patients with non-valvular atrial fibrillation rivaroxaban (20 mg/d) has been approved to prevent stroke or systemic embolism. The favourable benefit-risk profile of rivaroxaban in the treatment of deep vein thrombosis (DVT) was shown in EINSTEIN-DVT and led to its clinical approval (twice daily 15 mg for 3 weeks, followed by 20mg/d). Based on ATLASACS-TIMI-51 which has shown that rivaroxaban (2.5 mg twice daily) reduced thrombotic cardiovascular events and mortality in patients with a recent acute coronary syndrome, the approval of low dose rivaroxaban has been submitted for this indication.Taken together, rivaroxaban may become an effective alternative to standard anticoagulants in the prevention and treatment of thromboembolic disorders.

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Design and Quantitative Structure−Activity Relationship of 3-Amidinobenzyl-1H-indole-2-carboxamides as Potent, Nonchiral, and Selective Inhibitors of Blood Coagulation Factor Xa

Journal of Medicinal Chemistry ◽

10.1021/jm0111346 ◽

2002 ◽

Vol 45 (13) ◽

pp. 2749-2769 ◽

Cited By ~ 58

Author(s):

Hans Matter ◽

Elisabeth Defossa ◽

Uwe Heinelt ◽

Peter-Michael Blohm ◽

Detlev Schneider ◽

...

Keyword(s):

Blood Coagulation ◽

Factor Xa ◽

Coagulation Factor ◽

Quantitative Structure Activity Relationship ◽

Structure Activity Relationship ◽

Activity Relationship ◽

Quantitative Structure ◽

Selective Inhibitors ◽

Structure Activity ◽

Relationship Of

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Reversal of Factor Xa Inhibitors by Andexanet Alfa May Increase Thrombogenesis Compared to Pretreatment Values

Clinical and Applied Thrombosis/Hemostasis ◽

10.1177/1076029619863493 ◽

2019 ◽

Vol 25 ◽

pp. 107602961986349 ◽

Cited By ~ 3

Author(s):

Fakiha Siddiqui ◽

Alfonso Tafur ◽

Lorenzo Storino Ramacciotti ◽

Walter Jeske ◽

Debra Hoppensteadt ◽

...

Keyword(s):

Thrombin Generation ◽

Area Under The Curve ◽

Factor Xa ◽

Coagulation Factor ◽

Inhibitory Effects ◽

Clotting Time ◽

Reversal Effect ◽

Normal Human ◽

Fxa Inhibitor ◽

Andexanet Alfa

Recombinant coagulation factor Xa (FXa), inactivated Zh-zo, also known as andexanet alfa (AA), is a modified version of human FXa that has been developed to neutralize FXa inhibitors. We studied the reversal effect of AA for these inhibitors in various anticoagulant and thrombin generation (TG) assays. Individual aliquots of normal human plasma containing 1 µg/mL of apixaban, betrixaban, edoxaban, and rivaroxaban, were supplemented with saline or AA at a concentration of 100 µg/mL. Clotting profiles include prothrombinase-induced clotting time, activated partial thromboplastin time, and prothrombin time. Factor Xa activity was measured using an amidolytic method. Thrombin generation was measured using a calibrated automated thrombogram. Differential neutralization of all 4 anticoagulants was noted in the activated clotting time and other clotting tests. The FXa activity reversal profile varied with an observed decrease in apixaban (22%), betrixaban (56%), edoxaban (28%), and rivaroxaban (49%). Andexanet alfa also led to an increased TG in comparison to saline. The peak thrombin was higher (40%), area under the curve (AUC) increased (15%), whereas the lag time (LT) decreased (17%). Andexanet alfa added at 100 µg/mL to various FXa supplemented systems resulted in reversal of the inhibitory effects, restoring the TG profile; AUC, LT, and peak thrombin levels were comparable to those of unsupplemented samples. Andexanet alfa is capable of reversing anti-Xa activity of different oral FXa inhibitors but overshoots thrombogenesis in both the saline and FXa inhibitor supplemented systems. The degree of neutralization of Xa inhibitor is specific to each agent.

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Two parallel prothrombin activator systems in Australian rough-scaled snake, Tropidechis carinatus

Thrombosis and Haemostasis ◽

10.1160/th04-07-0435 ◽

2005 ◽

Vol 93 (01) ◽

pp. 40-47 ◽

Cited By ~ 14

Author(s):

Md. Abu Reza ◽

Sanjay Swarup ◽

Manjunatha Kini

Keyword(s):

Blood Coagulation ◽

Blood Clotting ◽

Cdna Sequence ◽

Factor Xa ◽

Coagulation Factor ◽

Venom Gland ◽

Factor X ◽

Specific Expression ◽

Life Saving ◽

Sequence Encoding

SummaryIt is uncommon for similar pathways/systems to be involved in highly divergent functions within single organisms. Earlier, we have shown that trocarin D, a venom prothrombin activator, from the Australian rough-scaled snake Tropidechis carinatus, is structurally and functionally similar to the blood coagulation factor Xa (FXa). The presence of a haemostatic system in these snakes implies that they have two parallel prothrombin activating systems: one in the plasma, that participates in the life saving process of blood clotting and the other in their venom, where it acts as a toxin. Here, we report the complete cDNA sequence encoding the blood coagulation factor X (FX) from the liver of T. carinatus. Deduced T. carinatus FX sequence shows ~80% identity with trocarin D but ~50% identity with the mammalian FX. Our present study confirms the presence of two separate genes – one each for FX and trocarin D, that code for similar proteins in T. carinatus snake. These two genes have different expression sites and divergent uses suggesting that snake venom prothrombin activators have probably evolved by the duplication of the liver FX gene and subsequently marked for tissue-specific expression in the venom gland.

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