• Journal of Applied Biological Chemistry
• /
• v.63 no.4
• /
• pp.339-345
• /
• 2020

Euchrestaflavanone A (EFA) is a flavonoid found in the root bark of Cudrania tricuspidata. C. tricuspidata extract, widely used throughout Asia in traditional medicine, has been investigated phytochemically and biologically and is known to have anti-obesity, anti-inflammatory, and anti-tumor effects. It has been reported that C. tricuspidata extract also possesses anti-platelet effects; however, the mechanism of its anti-platelet and anti-thrombotic activities is yet to be elucidated. In this study, we investigated the effects of EFA on the modulation of platelet function using collagen-induced human platelets. Our results showed that EFA markedly inhibited platelet aggregation. Furthermore, it downregulated glycoprotein IIb/IIIa (αIIb/β3)-mediated signaling events, including platelet adhesion, granule secretion, thromboxane A2 production, and clot retraction, but upregulated the cyclic adenosine monophosphate-dependent pathway. Taken together, EFA possesses strong anti-platelet and anti-thrombotic properties and is a potential therapeutic drug candidate to prevent platelet-related thrombosis and cardiovascular disease.

• YAKHAK HOEJI
• /
• v.37 no.5
• /
• pp.453-457
• /
• 1993

Platelet anti-aggregating activities were tested with analogs of protocatechuic acid and gallic acid. Six of them which showed comparable inhibitory effects with aspirin against collagen induced platelet aggregation were selected and their anti-thrombotic effects were evaluated in the mouse thrombosis model and compared with those of aspirin and paeonol. At the dose of 50 mg/kg, p.o., ethyl gailate(13) treated group showed higher % of recovery within 6 min of thrombotic challenge and lower mortality within 5 min than aspirin treated group.

• YAKHAK HOEJI
• /
• v.38 no.2
• /
• pp.191-196
• /
• 1994

Higenamine is a tetrahydroisoquinoline alkaloid which was isolated as a cardiotonic principle from Aconiti tuber. 1.v. injection of higenamine was reported to increase the cardiac output and heart rate and to decrease the blood pressure and the systemic vascular resistance presumably by stimulating the adrenergic ${\beta}-receptors$. The anti-platelet and anti-thrombotic effects of higenamine were investigated in this paper. Higenamine(0.5 mg/ml) showed mild inhibitory effect against collagen induced platelet aggregation in vitro and the inhibito교 effect was increased with the pre-incubation$(5{\sim}30\;min)$ of platelet rich plasma(PRP) with higenamine. With the 30 min incubation, the platelet aggregation was almost completely inhibited. And the oral administration of higenamine$(50{\sim}200\;mg/kg)$ enhanced the survival in the mouse model of thrombosis and that of endotoxic shock. The anti-thrombotic and anti-septic effects of higenamine thus appear to be due to the ${\beta}-agonistic$ and the anti-platelet effects of this compound.

• Korean Journal of Pharmacognosy
• /
• v.26 no.4
• /
• pp.385-389
• /
• 1995

MeOH extract of Gastrodia elata was fractionated to five solvent fractions, hexane fr (fr I), 90% MeOH fr (fr II), EtOAc fr (fr III), BuOH fr (fr IV) and $H_2O$ fr (fr V). Among the five fractions, fr II, III and IV showed platelet anti-aggregating effects against ADP or collagen induced rat platelet aggregation in vitro. Fr II , III and IV were also tested in vivo, in the mouse and rat models of thrombosis. Oral administration of fr II, III or IV enhanced the recovery from the thrombotic shock in the mouse model of thrombosis to 32-40% from 17% of recovery with the control group of mice. Treatment with fr II, III or IV also attenuated the sudden reduction in the blood platelet count following intravenous collagen injection to rat. The above results were indicative of the presence of anti-platelet and anti-thrombotic components in this plant.

• Archives of Pharmacal Research
• /
• v.26 no.9
• /
• pp.723-726
• /
• 2003

Five coumarins, isoimperatorin (1), pabulenol (2), isooxypeucedanin (3), oxypeucedanin hydrate (4) and osthol (5) were isolated from the MeOH extract of Angelica genuflexa in the course of searching for anti-platelet and anti-coagulant components from plants. Pabulenol (2) was isolated from A. genuflexa for the first time. The five compounds isolated from A. genuflexa, together with decursinol angelate (6), decursin (7) and nodakenin (8) from A. gigas were evaluated for their effects on platelet aggregation and blood coagulation. Compounds 2, 5, 6 and 7 were observed to be either equally effective or 2∼4 times more inhibitory than ASA in both arachidonic acid and U46619 ($TXA_2$ mimetic) induced platelet aggregations.

• Biomolecules & Therapeutics
• /
• v.23 no.2
• /
• pp.149-155
• /
• 2015

Our previous study demonstrated that yuzu has an anti-platelet effect in rat blood. In the present study, we examined whether the anti-platelet effect of yuzu can be extended to human blood by investigating its ability to inhibit aggregations induced by various agonists in human platelet rich plasma (PRP). This study also investigated the underlying mechanism of yuzu focusing on ADP granule secretion, $TXB_2$ formations, and $PLC{\gamma}$/Akt signaling. The results from this study showed that ethanolic yuzu extract (YE), and its components, hesperidin and naringin, inhibited human platelet aggregation in a concentration-dependent manner. YE, hesperidin and naringin also inhibited $TXB_2$ formation and ADP release. The phosphorylation of $PLC{\gamma}$ and Akt was significantly inhibited by YE, heperidin and naringin. Furthermore, we demonstrated that YE, heperidin and naringin has anti-platelet effects in rat ex vivo studies, and lower side effects in mice tail bleeding time studies. The results from this study suggest that YE, hesperidin and naringin can inhibit human platelet aggregation, at least partly through the inhibition of $PLC{\gamma}$ and Akt, leading to a decrease in $TXB_2$ formation and granule secretion.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.25 no.3
• /
• pp.471-481
• /
• 2011

Clove has been frequently used as anti-diabetic, anti-microbial, anti-inflammatory, anesthetic drug and remedies for stomachache by coldness. In this study, the antioxidant activity of extract from Clove was studied in vitro methods by measuring the antioxidant activity by TEAC, measuring the scavenging effects on reactive oxygen species (ROS) [superoxide anion, hydroxyl radical] and on reactive nitrogen species (RNS) [nitric oxide and peroxynitrite] as well as measuring the inhibitory effect on $Cu^{2+}$-induced human LDL oxidation. Anti-platelet aggregation and anti-thrombotic effects of Clove extracts were studied ex vivo methods by mesuring the inhibitory effect on thrombin induced platelet aggregation and the fibrinolytic activity. The Clove extracts were found to have a potent scavenging activity, as well as an inhibitory effect on LDL oxidation in vitro. Moreover Clove extracts were exhibited remarkable inhibitory effect on platelet aggregation and fibrinolytic activity. In conclusion, the Clove extracts have anti-oxidative and anti-atherosclerotic effects in vitro and ex vivo system, which can be used for developing pharmaceutical drug against oxidative stress and atherosclerosis.

• Biomedical Science Letters
• /
• v.25 no.4
• /
• pp.302-312
• /
• 2019

The aim of this work was to investigate the effect of black tea extract (BTE) on collagen -induced platelet aggregation. In this study, BTE (10~500 ㎍/mL) was shown to inhibit platelet aggregation via thromboxane A₂ (TXA₂) down-regulation by blocking cyclooxygenase-1 (COX-1) activity. Also, BTE decreased intracellular Ca²⁺ mobilization ([Ca²⁺]_i). Additionally, BTE enhanced the levels of both cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), which are aggregation-inhibiting molecules. BTE inhibited the phosphorylation of phospholipase C (PLC) γ2 and syk activated by collagen. BTE regulated platelet aggregation via cAMP-dependent phosphorylation of vasodilator-stimulated phosphoprotein (VASP) Ser¹⁵⁷. The anti-platelet effects of BTE in high fat diet (HFD)-induced obese rats were evaluated. After eight weeks of BTE treatment (300 and 600 mg/kg), the platelet aggregation rate in the treated groups was significantly less than that in the HFD-fed control group. Also, BTE exhibited a hepatoprotective effect and did not exert hepatotoxicity. Therefore, these data suggest that BTE has anti-platelet effects on collagen-stimulated platelet aggregation and may have therapeutic potential for the prevention of platelet-mediated thrombotic diseases.

• Proceedings of the PSK Conference
• /
• 2003.04a
• /
• pp.271.3-272
• /
• 2003

Rhus verniciflua Stokes (RVS) is a widely used herbal plant with various biological properties. Our previous study using in vitro platelet aggregation in whole blood showed that the fractions of RVS had strong anti-aggregatory activity. In this study, using in vitro platelet aggregation in PRP and coagulation parameters, to investigate the anti-platelet activity and anticagulant effects of RVS ethyl acetate layer, the layer was subsequently fractionated by ODS columm chromatograph (50％ MeOH). (omitted)

• Korean Journal of Pharmacognosy
• /
• v.51 no.4
• /
• pp.231-237
• /
• 2020

Euchrestaflavanone B (EFB) is a flavonoid that can be found in root bark, particularly in Cudrania tricuspidata (C. tricuspidata). The extract of C. tricuspidata is widespread throughout Asia and used in traditional medicine. In a previous study, we found anti-platelet effects of substances isolated from C. tricuspidata on collagen-induced human platelets. However, the C. tricuspidata still contains numerous substances, thus, we have searched new candidate, EFB isolated from C. tricuspidata for anti-platelet effect. Our results showed that EFA inhibited collagen-induced platelet aggregation and glycoprotein IIb/IIIa (αIIb/β3)-mediated signaling events, including platelet adhesion, granule secretion, thromboxane A2 production and clot retraction. These results suggest that EFA has inhibitory effects on human platelet activities and thrombus formation and has potential value as a natural substance for preventing platelet-induced thrombosis.