• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.2
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• pp.460-466
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• 2006

We wondered whether the mechanisms of antiplatelet aggregation of DJS-WE were through multiple pathways. Danggijakyak-san(DJS) consisting of 6 herbes of Paeoniae Radix, Poria Cocos, Angelicae Sinensis Radix, Cnidii Rhizoma, Atractylodis Macrocephalae Rhizoma and Alismatis Rhizoma, is a crude mixture of a commonly used Korean herbal medicine. The water extract (DJS-WE) of DJS has been known to have an anti-platelet aggregation activity. We have reported that DJS-WE inhibited ADP-induced aggregation as well as arachidonic acid-induced aggregation of human platelet. Clinical studies on the cardiovascular effects of DJS-WE have been done in Korea. The DJS has been used as a remedy for gastrointestinal disorders (abdominal pain, dysentery), headache, amenorrhea, and postpartum hemorrhage. It has also been claimed to have a remarkable central stimulant effect, a transient hypertensive effect, and positive inotropic and chronotropic effects. In this paper, we evaluated the possible mechanisms of the antiplatelet activity of DJS-WE using human platelets. On the other hand, the role of DJS-ethanol extract on the inhibition of platelet aggregation and hemolytic effect have not yet been investigated in detail. We also used the method of activated partial thromboplastin times (APTT) for the first time to study the inhibition on platelet aggregation activity of DJS-ethanol extract. The effect of DJS-WE on hemolysis was also investigated. DJS-WE showed a high hemolysis ability on human blood.

• The Korea Journal of Herbology
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• v.28 no.3
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• pp.39-44
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• 2013

Objectives : The purpose of this study was to identify active fraction and components from antiplatelet Ulmi cortex extract. Methods : The 70% ethanol extract of Ulmi cortex was subjected to column chromatography over D101 resin and eluted with an 20% (W1), 30% (W2), 40% (W3), 50%(W4), 70% (W5), and 100% ethanol (W6) to yield 6 fractions. W6 was further fractioned and its active components were purified using semi-preparative HPLC. The isolated compounds were identified by MS and NMR, and their contents were simultaneously analyzed using HPLC/UV. Antiplatelet aggregation activities of the fractions and the compounds were evaluated using rat platelet-rich plasma in presence of collagen ($5{\mu}g/ml$), arachidonic acid (0.05 U/ml), or thrombin ($100{\mu}M$). Results : Among six fractions, W3 prominently inhibited platelet aggregation. At the concentration of $200{\mu}g/ml$, W3 strongly inhibited arachidonic acid- and collagen-induced platelet aggregations by 78.2% and 65.9%, respectivley, and weakly inhibited thrombin-inducded platelet aggregation by 32.6%. Catechin, epicatehin, and catechin-7-O-${\beta}$-D-glucopyranoside were isolated from W3 and their contents were revealed to be 15.1%, 0.87%, and 0.32%. Catechin and epicatechin at the concentrations of $100{\mu}M$ strongly inhibited collagen-induced platelet aggregation by 79.9% and 86.6%, respectively, but weakly inhibited arachidonic acid- and thrombin-induced platelet aggregations. Conclusions : A main active principle of anitplatelet Ulmi Cortex extract is W3 fraction, of which main active component is catechin considering its antiplatelet activity and content.

• Biomedical Science Letters
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• v.23 no.3
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• pp.277-280
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• 2017

Elsholtzia splendens, which grows on moist soil of mountainous regions, is widely distributed at all regions of Korea, especially at Mountain Ji ri. It is categorized as a Labiatae plant which is dried aerial part. It has the following medicinal properties; removal of fever, alleviation of pain, a good antiphlogistic agent as well as antibacterial effects. However, the effects of E. splendens on thrombosis and platelet activation are not precisely understood. We performed this study to develop antithrombotic agents from oriental medicine herb extracts. E. splendens inhibited platelet aggregation induced by arachidonic acid and U46619 in a concentration dependent manner. E. splendens did not show an effect on anticoagulation as determined by prothrombin time (PT) or activated partial thromboplastin time (aPTT). We also tested the effects of E. splendens using a carotid artery thrombosis rat model induced by 35% $FeCl_3$ treatment. E. splendens significantly inhibited thrombus weight compared with the control group. These results show that E. splendens may be developed as a potential antiplatelet activity agent for treatment of cardiocerebrovascular disease and atherosclerosis.

• Journal of Microbiology and Biotechnology
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• v.12 no.4
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• pp.649-656
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• 2002

Fibrinolytic microorganisms were screened from 42 samples of Korean fermented food (7 kinds of Chungook-jang, 14 kinds of commercial Doen-Jang, 5 kinds of home-made Doen-jang, and 16 kinds of Jeot-gal), 15 samples of Japanese fermented food (5 kinds of home-made soybean paste, and 10 kinds of Natto), and 19 samples of Indonesian fermented food (Tempe) as well as starters of Meju (500 microflora from Korea, and 22 from China). Initially, 11 isolates with strong fibrinolytic activity were selected for further characterization. The fibrinolytic activity of the 11 isolates ranged from 89 to 199% of standard plasmin. Four strains, M5l from Korean fermented food (Meju), I 1-1, I 1-4, and I 5-1 from Indonesian fermented food (Tempe), were chosen based on the degree of activity and reproducibility, and identified as Staphylococcus sciuri, Citrobacter or Enterobacter, Enterococcus faecalis, and Bacillus subtilis, respectively. The first two isolates are pathogenic stains while the latter two are considered as GRAS (Generally Recognized As Safe). Fibrinolytic activity of E. faecalis, characterized and designated as BRCA-5, reached a maximum, when the producer was cultivated in Ml7 broth supplemented with 1.0% glucose for 5 h at 37$^{\circ}C$ with shaking at 180 rpm. Compared to commercial fibrinolytic enzymes, the cell-free culture supernatant of 5. faecaiis BRCA-5 showed stronger activity than plasmin and streptokinase, but similar degree of specific activity as nattokinase and urokinase, aud it also demonstrated anticoagulant and antiplatelet activity ex vivo. These features of E. faecalis make it an attractive agent as a biomaterial for health-promoting foods.

• Archives of Pharmacal Research
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• v.29 no.10
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• pp.898-903
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• 2006

The antiplatelet and antithrombotic activities of Korean Red Ginseng (KRG) were examined on rat carotid artery thrombosis in vivo, and platelet aggregation in vitro and ex vivo. Administration of KRG to rats not only prevented carotid artery thrombosis in vivo in a dose-dependent manner, but also significantly inhibited ADP- and collagen-induced platelet aggregation ex vivo, while failed to prolong coagulation times such as activated partial thromboplastin time (APTT) and prothrombin time (PT), indicating the antithrombotic effect of KRG might be due to its anti platelet aggregation rather than anticoagulation effect. In line with the above observations, KRG inhibited U46619-, arachidonic acid-, collagen- and thrombin-induced rabbit platelet aggregation in vitro in a concentration-dependent manner, with $IC_{50}$ values of $620{\pm}12$, $823{\pm}22$, $722{\pm}21$ and $650{\pm}14\;{\mu}g/mL$, respectively. Accordingly, KRG also inhibited various agonists-induced platelet serotonin secretions as it suppressed platelet aggregation. These results suggest that KRG has a potent antithrombotic effect in vivo, which may be due to antiplatelet rather than anticoagulation activity, and KRG intake may be beneficial to the individuals with high risks of thrombotic and cardiovascular diseases.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.543-544
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• 2005

• Proceedings of the PSK Conference
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• 2002.04a
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• pp.159.1-159.1
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• 2002

• YAKHAK HOEJI
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• v.43 no.6
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• pp.809-817
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• 1999

The effect of 2-(4-cyanophenyl)amino-1,4-naphthalenedione-3-pyridinium perchlorate (PQ5) on pla-telet aggregation and its action mechanisms were investigated with rat platelet. PQ5 inhibited the platelet aggregation induced by collagen ($6{\;}{\mu\textrm{g}}/ml$), thrombin (0.4 U/ml) and A23187 ($3{\mu}M$) in concentration-dependent manner with $IC_{50}$ values of 5.50, 25.89 and $37.12{\;}{\mu}M$, respectively. PQ5 also significantly reduced the thromboxane $A_2$ (TXA2) formation in a concentration dependent manner. The collagen-induced arachidonic acid (AA) release in [-3H]-AA incorporated platelet, an indication of the phospholipase $A_2$ activity, was decreased by PQ5 pretreatment PQ5 significantly inhibited the activity of thormboxane synthase only at high concentration ($100{\mu}M$), but did not affect the cyclooxygenase activity at all. Collagen-induced ATP release was significantly reduced by PQ5. Calcium-induced platelet aggregation experiment suggests that the elevation of intracellular free $Ca^{2+}$ concentration ($[Ca^{2+}]_i$) by collagen stimulation is decreased by the pretreatment of PQ5, which is due to the inhibition of calcium release from intracellular store and influx from outside of the cell. PQ5 did not showed the effect of anticoagulation as prothrombin time (PT) or activated partial thromboplastin time (APTT). Form these results, it is suggested that PQ5 exerts its antiplatelet activity through the inhibition of the intracellular $Ca^{2+}$ mobilization and the decrease of the $TXA_2$ synthesis.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.137.2-138
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• 2003

The steam distillate obtained from sawdust of Thujopsis dolabrata var. hondai was fractionated by centrifugal thin-film evaporation. and then the fractions were investigated against antiplatelet activity using washed rabbit platelets in vitro. The biologically active constituent of T. dolabrata sawdust was isolated by silica gel column chromatography and HPLC and characterized as carvacrol by various spectral analysis ($^{1}H$, $^{13}C$-NMR and GC/MS studies). (omitted)

• Biomedical Science Letters
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• v.27 no.4
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• pp.270-276
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• 2021

Physiological agents trigger a signaling process called "inside-out signaling" and activated platelets promote adhesion, granule release, and conformational changes of glycoprotein IIb/IIIa (αIIb/β₃). Activated αIIb/β₃ interacts with fibrinogen and initiates a second signaling step called "external signaling". These two signaling pathways can cause hemostasis or thrombosis, and thrombosis is a possible medical problem in arterial and venous vessels, and platelet-mediated thrombosis is a major cause of cardiovascular disease (CVD). Therefore, modulating platelet activity is important for platelet-mediated thrombosis and cardiovascular disease. Esculetin is a coumarin-based physiologically active 6,7-dihydroxy derivative known to have pharmacological activity against obesity, diabetes, renal failure and CVD. Although some studies have confirmed the effects of esculetin in human platelet activation and experimental mouse models, it is not clear how esculetin has antiplatelet and antithrombotic effects. We confirmed the effect and mechanism of action of escultein on human platelets induced by collagen. As a result, esculetin decreased Ca²⁺ recruitment through upregulation of inositol 1, 4, 5-triphosphate receptor. In addition, esculetin upregulates cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP)-dependent pathways and inhibits fibrinogen binding and thrombus contraction. Our results demonstrate the antiplatelet effect and antithrombotic effect of esculetin in human platelets. Therefore, we suggest that esculetin could be a potential phytochemical for the prevention of thrombus-mediated CVD.