benzofurans and Thrombosis

Topics: Adult; Aged; Benzbromarone; Benzofurans; Female; Fibrinolytic Agents; Humans; Male; Middle Aged; Premedication; Thrombosis; Varicose Veins

Dieckol is a phlorotannin that can be found in seaweeds, particularly in Eisenia bicyclis (brown algae) and is known to have anti-oxidant, anti-inflammatory, and anti-microbial properties. It also possesses anti-thrombotic and pro-fibrinolytic activities; however, the mechanistic aspects of anti-platelet and anti-thrombotic activity are yet to be explored.. We investigated the pharmacological effects of dieckol on the modulation of platelet functions using human, rat, and mice models. Inhibitory effects of dieckol on platelet aggregation were assessed using platelet-rich plasma and washed platelets, followed by measurement of dense granule secretions, fibrinogen binding to integrin α. Dieckol markedly inhibited platelet aggregation and granule secretion; furthermore, it down-regulated integrin α. Dieckol possesses strong anti-platelet and anti-thrombotic properties and is a potential therapeutic drug candidate to treat and prevent platelet-related cardiovascular disorders.

Topics: Animals; Benzofurans; Blood Platelets; Fibrinogen; Hemostasis; Humans; Mice; Platelet Aggregation; Platelet Glycoprotein GPIIb-IIIa Complex; Rats; Thrombosis

Protease-activated receptor 4 (PAR4) is a G-protein coupled receptor that is expressed on human platelets and activated by the coagulation enzyme thrombin. PAR4 plays a key role in blood coagulation, and its importance in pathological thrombosis has been increasingly recognized in recent years. Herein, we describe the optimization of a series of imidazothiadiazole PAR4 antagonists to a first-in-class clinical candidate, BMS-986120 (

Topics: Benzofurans; Blood Platelets; Humans; Imidazoles; Morpholines; Platelet Aggregation; Receptor, PAR-1; Receptors, Thrombin; Thiazoles; Thrombin; Thrombosis

The root of Salvia miltiorrhiza f. alba (RSMA) (Lamiaceae) is used for the treatment of patients with thromboangiitis obliterans (TAO) in traditional Chinese medicine. Previously, a mixture of phenolic acids extracted from RSMA has shown significant protective effects on TAO rats.. This study investigates the inhibitory effects of salvianolic acid B on TAO induced by sodium laurate injection in rats to explore the effective constituents of RSMA in TAO treatment.. TAO rats were developed using injected sodium laurate. After treatment with ligustrazine hydrochloride (15 mg/kg) and various doses of salvianolic acid B (10, 20, 40 mg/kg) by tail intravenous injection, levels of thromboxane B. Salvianolic acid B significantly decreased the expressions of TXB. Salvianolic acid B has a protective effect on TAO rats. The mechanism may involve inhibition of thrombosis and TAO-associated inflammatory responses, which may explain the success of RSMA treatment of TAO in humans in traditional Chinese medical practice. Hence, it may be a potential drug for TAO treatment in conventional medicine.

Topics: Animals; Benzofurans; Humans; Inflammation; Lauric Acids; Male; Medicine, Chinese Traditional; Plant Roots; Rats; Rats, Wistar; Salvia miltiorrhiza; Thromboangiitis Obliterans; Thrombosis

In an effort to identify novel antithrombotics, we have investigated protease-activated receptor 4 (PAR4) antagonism by developing and evaluating a tool compound,

Topics: Animals; Benzofurans; Biological Availability; Disease Models, Animal; Fibrinolytic Agents; HEK293 Cells; Hemorrhage; Humans; Macaca fascicularis; Models, Chemical; Molecular Structure; Platelet Aggregation; Receptors, Thrombin; Structure-Activity Relationship; Thrombosis

In the present study, a series of novel nitric oxide-hydrogen sulfide releasing derivatives of (S)-3-n-butylphthalide ((S)-NBP) were designed, synthesized, and evaluated as potential antiplatelet agents. Compound NOSH-NBP-5 displayed the strongest activity in inhibiting the arachidonic acid (AA)- and adenosine diphosphate (ADP)-induced platelet aggregation in vitro, with 3.8- and 7.0-fold more effectiveness than (S)-NBP, respectively. Furthermore, NOSH-NBP-5 could release moderate levels of NO and H

Topics: Animals; Benzofurans; Humans; Hydrogen Sulfide; Male; Molecular Structure; Nitric Oxide; Platelet Aggregation; Platelet Aggregation Inhibitors; Rabbits; Rats; Rats, Sprague-Dawley; Thrombosis

Rhus verniciflua stokes (RVS) is known to promote blood circulation by preventing blood stasis, although the active ingredients and the underlying mechanism are unclear. Platelets are the primary cells that regulate circulation and contribute to the development of diverse cardiovascular diseases by aggregation and thrombosis. The study assessed the antiplatelet activity of RVS and sought to identify the active constituents. Pretreatment of washed platelets with RVS heartwood extract blunted the aggregatory response of platelets to collagen. In the subfractions, fisetin, butein, and sulfuretin were identified as effective inhibitors of platelet aggregation by collagen, thrombin, and adenosine-5'-diphosphate. Antiplatelet activities of all three compounds were concentration dependent, and fisetin had longer in vitro duration of action compared with butein or sulfuretin. Extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase activation by collagen was prevented by fisetin, whereas butein and sulfuretin failed to inhibit ERK and p38 activation was not affected by any of the compounds. Rats orally administered 100 mg/(kg·day(-1)) fisetin for 7 days were resistant to arterial thrombosis, although total extract of RVS heartwood exhibited little effect at a dose of 1000 mg/(kg·day(-1)). RVS heartwood may have cardiovascular protective activity by inhibiting platelet aggregation. The active constituents are fisetin, butein, and sulfuretin, and fisetin is orally effective against thrombosis.

Topics: Animals; Benzofurans; Blood Platelets; Cardiovascular Diseases; Chalcones; Dose-Response Relationship, Drug; Extracellular Signal-Regulated MAP Kinases; Flavonoids; Flavonols; Male; p38 Mitogen-Activated Protein Kinases; Phytotherapy; Plant Extracts; Platelet Aggregation; Platelet Aggregation Inhibitors; Rats, Sprague-Dawley; Rhus; Thrombosis; Wood

To develop novel anti-ischemic stroke agents with better therapeutic efficacy and bioavailability, we designed and synthesized a series of 3-alkyl-2,3-dihydro-1H-isoindol-1-ones compounds (3a-i) derivatives, one of which (3d) exhibited the strongest inhibitory activity for the adenosine diphosphate-induced and arachidonic acid-induced platelet aggregation. This activity is superior to that of 3-n-butylphthalide and comparable with aspirin and edaravone. Meanwhile, 3d not only exhibited a potent activity in scavenging free radicals and improving the survival of HT22 cells against the reactive oxygen species-mediated cytotoxicity in vitro but also significantly attenuated the ischemia/reperfusion-induced oxidative stress in ischemic rat brains. Results from transient middle cerebral artery occlusion and permanent middle cerebral artery occlusion model, indicated that 3d could significantly reduce infarct size, improve neurobehavioral deficits, and prominently decrease attenuation of cerebral damage. Most importantly, 3d possessed a very high absolute bioavailability and was rapidly distributed in brain tissue to keep high plasma drug concentration for the treatment of ischemic strokes. In conclusion, our findings suggest that 3-alkyl-2,3-dihydro-1H-isoindol-1-ones, a novel series of compounds, might be candidate drugs for the treatment of acute ischemic strokes, and 3d may be a promising therapeutic agent for the primary and secondary prevention of ischemic stroke.

Topics: Animals; Antioxidants; Antipyrine; Behavior, Animal; Benzofurans; Biological Availability; Brain; Carrageenan; Cell Line; Disease Models, Animal; Edaravone; Fibrinolytic Agents; Infarction, Middle Cerebral Artery; Isoindoles; Male; Mice; Molecular Structure; Neuroprotective Agents; Oxidative Stress; Platelet Aggregation; Platelet Aggregation Inhibitors; Rats, Sprague-Dawley; Reperfusion Injury; Structure-Activity Relationship; Thrombosis; Tissue Distribution

Interactions between platelet glycoprotein (Gp) IIb/IIIa and plasma proteins mediate platelet cross-linking in arterial thrombi. However, GpIIb/IIIa inhibitors fail to disperse platelet aggregates after myocardial infarction or ischemic stroke. These results suggest that stability of occlusive thrombi involves additional and as-yet-unidentified mechanisms. In the present study, we investigated the mechanisms driving platelet cross-linking during occlusive thrombus formation. Using computational fluid dynamic simulations and in vivo thrombosis models, we demonstrated that the inner structure of occlusive thrombi is heterogeneous and primarily determined by the rheological conditions that prevailed during thrombus growth. Unlike the first steps of thrombus formation, which are GpIIb/IIIa-dependent, our findings reveal that closure of the arterial lumen is mediated by GpIbα-von Willebrand Factor (VWF) interactions. Accordingly, disruption of platelet cross-linking using GpIbα-VWF inhibitors restored vessel patency and improved outcome in a mouse model of ischemic stroke, although the thrombi were resistant to fibrinolysis or traditional antithrombotic agents. Overall, our study demonstrates that disruption of GpIbα-VWF interactions restores vessel patency after occlusive thrombosis by specifically disaggregating the external layer of occlusive thrombi, which is constituted of platelet aggregates formed under very high shear rates.

Topics: Animals; Benzofurans; Blood Platelets; Blood Vessels; Hemorheology; Male; Mice; Platelet Aggregation; Platelet Glycoprotein GPIb-IX Complex; Protein Interaction Maps; Quinolines; Thrombosis; von Willebrand Factor

The recently discovered chemokine CXC motif ligand 16 (CXCL16) is highly expressed in atherosclerotic lesions and is a potential pathogenic mediator in coronary artery disease.. The aim of this study was to test the role of CXCL16 on platelet activation and vascular adhesion, as well as the underlying mechanism and signaling pathway.. Reverse-transcriptase polymerase chain reaction, Western blotting, confocal microscopy, and flow cytometry revealed that CXCL16-specific receptor, CXC motif receptor 6, is highly expressed in platelets. According to flow cytometry and confocal microscopy, stimulation of platelets with CXCL16 induced platelet degranulation, integrin α(IIb)β(3) activation, and shape change. CXCL16 increased Akt phosphorylation (Thr(308)/Ser(473)), an effect abrogated by phosphatidylinositide 3-kinase inhibitors wortmannin (100 nmol/L) and LY294002 (25 µmol/L). The phosphatidylinositide 3-kinase inhibitors and Akt inhibitor SH-6 (20 µmol/L) further diminished CXCL16-induced platelet activation. CXCL16-mediated platelet degranulation, integrin α(IIb)β(3) activation, and Akt phosphorylation were blunted in platelets lacking CXCL16-specific receptor CXC motif receptor 6. CXCL16-induced platelet activation was abrogated in Akt1- or Akt2-deficient platelets. CXCL16 enhanced platelet adhesion to endothelium in vitro after high arterial shear stress (2000(-s)) and to injured vascular wall in vivo after carotid ligation. CXCL16-induced stimulation of platelet adhesion again was prevented by phosphatidylinositide 3-kinase and Akt inhibitors. Apyrase and antagonists of platelet purinergic receptors P(2)Y(1) (MRS2179, 100 µmol/L) and especially P(2)Y(12) (Cangrelor, 10 µmol/L) blunted CXCL16-triggered platelet activation as well as CXCL16-induced platelet adhesion under high arterial shear stress in vitro and after carotid ligation in vivo.. The inflammatory chemokine CXCL16 triggers platelet activation and adhesion via CXC motif receptor 6-dependent phosphatidylinositide 3-kinase/Akt signaling and paracrine activation, suggesting a decisive role for CXCL16 in linking vascular inflammation and thrombo-occlusive diseases.

Topics: Animals; Benzofurans; Blood Platelets; Chemokine CXCL16; Chemokine CXCL6; Coronary Artery Disease; Endothelium, Vascular; Female; Humans; Male; Mice; Mice, Mutant Strains; Phosphatidylinositol 3-Kinases; Platelet Activation; Platelet Adhesiveness; Proto-Oncogene Proteins c-akt; Quinolines; Receptors, CXCR; Receptors, CXCR6; Signal Transduction; Thrombosis; Vasculitis

Novel nitric oxide (NO) releasing derivatives (7a-7l) of 3-n-butylphthalide (NBP) were designed and synthesized. Compound 7e inhibited the adenosine diphosphate (ADP), thrombin (TH) and arachidonic acid (AA)-induced in vitro platelet aggregation, superior to NBP and aspirin, released moderate levels of NO, and improved aqueous solubility relative to NBP. Furthermore, 7e exhibited greater antithrombotic activity than NBP and aspirin in rats, and protected against collagen and adrenaline-induced thrombosis in mice. Therefore, NO-releasing NBP derivatives possessed potent antiplatelet aggregation and antithrombotic activity. Our findings may aid in the design of new therapeutic agents for the treatment of thrombosis-related ischemic stroke.

Topics: Animals; Benzofurans; Blood Platelets; Drug Synergism; Fibrinolytic Agents; Male; Mice; Nitric Oxide; Platelet Aggregation Inhibitors; Rats; Rats, Sprague-Dawley; Thrombosis

This study was designed to determine the effect of inhibitors of cyclooxygenase (COX)-1, COX-2, and the nonselective COX inhibitor naproxen on coronary vasoactivity and thrombogenicity under baseline and lipopolysaccharide (LPS)-induced inflammatory conditions. We hypothesize that endothelial COX-1 is the primary COX isoform in the canine normal coronary artery, which mediates arachidonic acid (AA)-induced vasodilatation. However, COX-2 can be induced and overexpressed by inflammatory mediators and becomes the major local COX isoform responsible for the production of antithrombotic prostaglandins during systemic inflammation. The interventions included the selective COX-1 inhibitor SC-560 (0.3 mg/kg iv), the selective COX-2 inhibitor nimesulide (5 mg/kg iv), or the nonselective COX inhibitor naproxen (3 mg/kg iv). The selective prostacyclin (IP) receptor antagonist RO-3244794 (RO) was used as an investigational tool to delineate the role of prostacyclin (PGI(2)) in modulating vascular reactivity. AA-induced vasodilatation of the left circumflex coronary artery was suppressed to a similar extent by each of the COX inhibitors and RO. The data suggest that AA-induced vasodilatation in the normal coronary artery is mediated by a single COX isoform, the constitutive endothelial COX-1, which is reported to be susceptible to COX-2 inhibitors. The effect of the COX inhibitors on thrombus formation was evaluated in a model of carotid artery thrombosis secondary to electrolytic-induced vessel wall injury. Pretreatment with LPS (0.5 mg/kg iv) induced a systemic inflammatory response and prolonged the time-to-occlusive thrombus formation, which was reduced in the LPS-treated animals by the administration of nimesulide. In contrast, neither SC-560 nor naproxen influenced the time to thrombosis in the animals pretreated with LPS. The data are of significance in view of reported adverse cardiovascular events observed in clinical trials involving the use of selective COX-2 inhibitors, thereby suggesting that the endothelial constitutive COX-1 and the inducible vascular COX-2 serve important functions in maintaining vascular homeostasis.

Topics: Acetylcholine; Animals; Arachidonic Acid; Benzofurans; Carotid Arteries; Coronary Circulation; Coronary Vessels; Cyclooxygenase 1; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Disease Models, Animal; Dogs; Dose-Response Relationship, Drug; Electric Stimulation; Epoprostenol; Inflammation; Ligation; Lipopolysaccharides; Naproxen; Platelet Aggregation; Propionates; Pyrazoles; Receptors, Epoprostenol; Sulfonamides; Thrombosis; Time Factors; Vasodilation; Vasodilator Agents

3-n-butylphthalide (NBP) is a potentially beneficial drug for the treatment of ischemic stroke with multiple actions on different pathophysiological processes. In the present study, the effect of l-, d-, and dl-NBP was investigated on ADP-, collagen-, and AA-induced platelet aggregation. l-NBP was the most potent among l-, d-, and dl-NBP. At higher concentration the effect of dl-NBP on platelet aggregation was greater than that of l- or d-NBP alone. The ex vivo antiaggregatory activity of l-NBP 100mg/kg declined gradually after 2 hours, but a considerable antiplatelet activity was still observed 4h after l-NBP administration. NBP was given orally and resulted in a dose-dependent inhibition of thrombus formation. Of the two isomers, l-NBP was the most potent. It significantly protected mice from a mixture of collagen and epinephrine induced thromboembolic death. When 100 mg/kg of l-NBP were administered orally to rats, the bleeding time increased 2.1-fold compared with the control group. At the same dose, ex vivo platelet aggregation induced by ADP, collagen, and AA was inhibited by l-NBP and the antithrombotic effects of the compound were also observed. Thus, NBP exerts oral anti-platelet and anti-thrombotic efficacy without perturbing systemic hemostasis in rats. l-NBP is more potent than d- and dl-NBP as antiplatelet agent.

Topics: Animals; Benzofurans; Bleeding Time; Fibrinolytic Agents; Male; Mice; Platelet Aggregation; Platelet Aggregation Inhibitors; Rats; Rats, Wistar; Thrombosis

Plasminogen activator inhibitor-1 (PAI-1) is the major physiological inhibitor of both tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA). Elevated levels of PAI-1 are associated with thrombosis and vascular disease, suggesting that high plasma PAI-1 may promote a hypercoagulable state by disrupting the natural balance between fibrinolysis and coagulation. In this study, we identify WAY-140312 as a structurally novel small molecule inactivator of PAI-1, compare its inhibitory activity with other previously identified small molecule inhibitors, and investigate the mechanism of inactivation of PAI-1 in the presence of both tPA and uPA. In an immunofunctional assay, WAY-140312 inhibited PAI-1 with an estimated inhibitory concentration (IC(50)) of 11.7 micro m, which was the lowest value obtained of the four different PAI-1 inactivators tested. Surface activity profiling indicated that the critical micelle concentration for WAY-140312 was 95.8 micro m, and that each inhibitor exhibited unique physical chemical properties. Using a sensitive direct activity assay, the IC(50) for WAY-140312 was similar when either tPA or uPA was used as the target protease. Immunoblot analysis demonstrated that WAY-140312 near the IC(50) inhibited the complex formation between either tPA or uPA and PAI-1. After oral administration, WAY-140312 exhibited 29% bioavailability with a plasma half-life of approximately 1 h. In an in-vivo model of vascular injury, a 10 mg kg(-1) oral dose of WAY-140312 was associated with improvement in arterial blood flow and reduction in venous thrombosis. Thus, WAY-140312 represents a structurally novel small molecule inhibitor of PAI-1, and is the first such molecule to exhibit efficacy in animal models of vascular disease following oral administration.

Topics: Administration, Oral; Animals; Arteries; Benzofurans; Blood Chemical Analysis; Blood Coagulation; Carotid Arteries; Dose-Response Relationship, Drug; Fibrinolysis; Immunoassay; Immunoblotting; Inhibitory Concentration 50; Micelles; Models, Chemical; Plasminogen Activator Inhibitor 1; Plasminogen Inactivators; Rats; Tetrazoles; Thrombosis; Time Factors; Urokinase-Type Plasminogen Activator

To study the effects of dl-, l- and d-3-n-butylphthalide (NBP) on platelet aggregation and thrombus formation.. Thrombus formation was assessed by silk thread-induced thrombosis in arteriovenous shunt in rats. Rat platelet aggregation induced by adenosine diphosphate (ADP), arachidonic acid (AA), collagen and thrombin was detected in vitro. The generation of thromboxane B2 (TXB2) and the concentration of cAMP in rabbit platelets in vitro were studied with radioimmunological assay.. dl-, l-NBP (5, 10, 20 mg.kg-1 i.p.) exhibited a dose-dependent inhibitory effect on thrombus formation in rats, while d-NBP was not active. dl, l, d-NBP (3-100 mumol.L-1) inhibited platelet-rich plasma aggregation in vitro induced by ADP, collagen and AA, and all of them showed no effect on thrombin-induced platelet aggregation. In addition, dl, l-NBP (10-100 mumol.L-1) were found to increase [cAMP]i in dose-related fashion. In the meantime, only high concentration of l-NBP was found to decrease platelet TXA2 level. In addition, l-NBP (1-100 mumol.L-1) showed significant effect on inhibiting 5-HT release from platelets. In contrast, dl- and d-NBP showed no effect.. The results suggest that NBP is a potent antiplatelet drug, the mechanism of its antithrombotic and antiplatelet activity is related to its regulation of cAMP level and 5-HT release.

Topics: Animals; Benzofurans; Blood Platelets; Cyclic AMP; Fibrinolytic Agents; Male; Neuroprotective Agents; Platelet Aggregation; Rabbits; Random Allocation; Rats; Rats, Sprague-Dawley; Serotonin; Stereoisomerism; Thrombosis

The purpose of this study was to assess the success of endothelial cell-seeded and non-seeded small-diameter vascular grafts in dogs medicated with antiplatelet agents. Eighty dogs underwent bilateral carotid artery replacements with 6 cm lengths of 4 mm I.D. double-velour Dacron grafts. In each dog one graft was seeded with enzymatically derived autologous endothelial cells; the contralateral graft was nonseeded. The following anti-platelet medications were administered beginning 4 days preoperatively: aspirin (5 grains every day); dipyridamole (50 mg twice a day); aspirin plus dipyridamole (5 grains each day plus 50 mg twice a day); aspirin (1.25 grains every other day); ibuprofen (10 mg/kg/day); U-53,059, a cyclooxygenase inhibitor (3 mg/kg/day); and U-63557A, a thromboxane synthase inhibitor (10 mg/kg/day). Grafts were harvested 5 weeks postoperatively. Graft success was evaluated by patency, thrombus-free surface area, area endothelialized, and graft production of prostacyclin. None of the medications prevented neoendothelialization of seeded grafts. Mean patencies of endothelial cell-seeded grafts from medicated dogs were significantly greater than mean patencies of endothelial cell-seeded grafts from nonmedicated dogs. The cyclooxygenase inhibitors best maintained patency in nonseeded grafts. Thrombus-free surface areas of endothelial cell-seeded grafts from medicated dogs were significantly greater than from nonseeded control grafts from the medicated dogs. All medications impaired prostacyclin synthesis. We conclude that the combination of endothelial cell seeding plus antiplatelet medication is most efficacious in small-vessel grafting success and that high levels of prostacyclin production by vascular grafts are not necessary to maintain patency in dogs medicated with antiplatelet agents.

Topics: Animals; Aspirin; Benzofurans; Blood Platelets; Blood Vessel Prosthesis; Carotid Arteries; Dipyridamole; Dogs; Endothelium; Female; Graft Occlusion, Vascular; Ibuprofen; Male; Polyethylene Terephthalates; Random Allocation; Thrombosis; Thromboxane-A Synthase

Topics: Animals; Benzofurans; Femoral Artery; Fibrinolytic Agents; In Vitro Techniques; Isonicotinic Acids; Rats; Thrombosis; Time Factors

Topics: Administration, Oral; Animals; Benzoates; Benzofurans; Dogs; Femoral Artery; Fibrinolytic Agents; Injections, Intravenous; Ligation; Platelet Adhesiveness; Thrombosis