• Journal of Applied Biological Chemistry
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• 제65권3호
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• pp.167-172
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• 2022

Pathophysiological reaction of platelets in the blood vessel is an indispensable part of thrombosis and cardiovascular disease, which is the most common cause of death in the world. In this study, we performed in vitro assays to evaluate antiplatelet activity of artemether in human platelets and attempted to identify the mechanism responsible for protein phosphorylation. Artemether is a derivative of artemisinin, known as an active ingredient of Artemisia annua, which has been reported to be effective in treating malaria, and is known to function through antioxidant and metabolic enzyme inhibition. However, the role of artemether in platelet activation and aggregation and the mechanism of action of artemether in collagen-induced human platelets are not known until now. In this study, the effect of artesunate on collagen-induced human platelet aggregation was confirmed and the mechanism of action of artemether was clarified. Artemether inhibited the phosphorylation of PI3K/Akt and Mitogen-activated protein kinases, which are phosphoproteins that are known to act in the signal transduction process when platelets are activated. In addition, artemether decreased TXA₂ production and decreased granule secretion in platelets such as ATP and serotonin release. As a result, artemether strongly inhibited platelet aggregation induced by collagen, a strong aggregation inducer secreted from vascular endothelial cells, with an IC₅₀ of 157.92 μM. These results suggest that artemether has value as an effective antithrombotic agent for inhibiting the activation and aggregation of human platelets through vascular injury.

• 동의생리병리학회지
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• 제20권2호
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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.

• 농업생명과학연구
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• 제43권1호
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• pp.25-33
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• 2009

본 연구는 홀스타인, 한국재래산양 및 한우유로부터 glycomacropeptide(GMP)를 분리하였으며, 각 GMP의 trypsin 가수분해물의 혈소판응집 억제 효과를 in vitro상에서 알아보았다. 홀스타인, 한국재래산양 및 한우의 GMP는 분자량이 모두 약 20 KDa이었으며, sialic acid 함량은 각각 $36.86{\pm}2.36$, $37.98{\pm}1.27$ 및 $31.19{\pm}1.87{\mu}g/mg$이었다. 또한 모든 개체의 GMP에서 tyrosine이 검출되었다. 홀스타인, 한국재래산양 및 한우 GMP의 trypsin 가수분해물에 의한 혈소판 응집 억제율은 반응 30초에 4.02, 5.51 및 12.77%로 각각 나타나 시간이 경과할수록 감소하는 경향을 보였다. 혈소판의 현미경 관찰 결과 가수분해물 첨가 후 혈소판 수가 증가하였으나, 첨가 후 30초가 경과한 시점부터 혈소판 수가 감소하기 시작하여 120초 후에는 관찰 할 수 없었다. 본 실험 결과 bovine 및 caprine GMP의 trypsin 가수분해물에서 혈소판 응집을 억제할 수 있는 small peptide가 있는 것으로 생각되며, 향후 이러한 연구는 심근경색증 및 뇌혈전증을 예방할 수 있는 생리활성 물질로 이용될 수 있을 것이라 생각된다.

• Biomolecules & Therapeutics
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• 제23권2호
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• pp.149-155
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• 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 Applied Biological Chemistry
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• 제64권3호
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• pp.317-322
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• 2021

Among the different cardiovascular disorders (CVDs), the activation of platelets is a necessary step. Based on this knowledge, therapeutic treatments for CVDs that target the disruption of platelet activation are proving to be worthwhile. One such substance, a bioactive 6,7-dihydroxy derived from coumarin, is 6,7-Dihydroxy-2H-1-benzopyran-2-one (esculetin). This compound has demonstrated several pharmacological effects on CVDS as well as various other disorders including diabetes, obesity, and renal failure. In various reports, esculetin and its effect has been explored in experimental mouse models, human platelet activation, esculetin-inhibited collagen, and washed human platelets exhibiting aggregation via arachidonic acid. Yet, esculetin affected aggregation with agonists like U46619 or thrombin in no way. This study investigated esculetin and how it affected human platelet aggregation activated through U46619. Ultimately, we confirmed that esculetin had an effect on the aggregation of human platelets when induced from U46619 and clarified the mechanism. Esculetin interacts with the downregulation of both phosphoinositide 3-kinase/Akt and mitogen-activated protein kinases, important phosphoproteins that are involved in activating platelets and their signaling process. The effects of esculetin reduced TXA₂ production, phospholipase A₂ activation, and platelet secretion of intracellular granules (ATP/serotonin), ultimately causing inhibition of overall platelet aggregation. These results clearly define the effect of esculetin in inhibiting platelet activity and thrombus formation in humans.

• 한국한의학연구원논문집
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• 제9권2호
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• pp.55-67
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• 2003

To evaluate anti-aggregatory activity of traditional prescriptions and medicines for treatment of Ohyul symptom, 70% methanol extracts were examined using collagen stimulated in vitro platelet aggregation by impedance method in rat whole blood. The crude extracts from DoHaekSeungKiTang, BoYangHwanOhTang, Caesalpinia sappan, Rhus verniciflua, Rheum palmatum, Polygonum cuspidatum, Salvia miltiorrhiza were found to inhibit platelet aggregation. The effective crude extracts of traditional medicine were fractionated to dichloromethane, ethyl acetate, butanol and aqueous layer. Polygonum cuspidatum, Caesalpinia sappan aud Rhus verniciflua ethyl acetate fractions concentration-dependently $(250-50{\mu}m/ml)$ inhibited the aggregation of platelet in whole blood induced by collagen. These results suggested that ethyl acetate fractions of Polygonum cuspidatum, Caesalpinia sappan and Rhus verniciflua have potent anti-aggregatory activity.

• Natural Product Sciences
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• 제26권4호
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• pp.295-302
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• 2020

Cudrania tricuspidata (C. tricuspidata) is a deciduous tree found in Japan, China and Korea. The root, stems, bark and fruit of C. tricuspidata has been used as traditional herbal remedies such as eczema, mumps, acute arthritis and tuberculosis. In this study, we investigated the potential efficacies of this natural compound by focusing on the inhibitory effect of cudraxanthone L (CXL) isolated from the roots of C. tricuspidata on human platelet aggregation. Our study focused on the action of CXL on collagen-stimulated human platelet aggregation, inhibition of platelet signaling molecules such as fibrinogen binding, intracellular calcium mobilization, fibronectin adhesion, dense granule secretion, and thromboxane A2 secretion. In addition, we investigated the inhibitory effect of CXL on thrombin-induced clot retraction. Our results showed that CXL inhibited collagen-induced human platelet aggregation, intracellular calcium mobilization, fibrinogen binding, fibronectin adhesion and clot retraction without cytotoxicity. Therefore, we confirmed that CXL has inhibitory effects on human platelet activities and has potential value as a natural substance for preventing thrombosis.

• 생약학회지
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• 제17권1호
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• pp.19-22
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• 1986

As a continuation of the previous work, a second group of sixty solvent fractions prepared from twenty plant species were screened for their inhibitory effects on adenosine 5'-diphosphate (ADP)-, arachidonic acid (AA)- or collagen-induced rat platelet aggregation. The results suggested that five plant species including Angelica koreana, Cassia obtusifolia, Gastrodia elata, Paeonia lactiflora and Salvia miltiorrhiza are potential sources of inhibitors of platelet aggregation.

• Journal of Ginseng Research
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• 제17권3호
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• pp.246-249
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• 1993

Hexane, Hexane/diethylether and chloroform fractions from Panax ginseng C.A. Meyer stroungly inhibitied human platelet aggregation induced by a high dose of thrombin (2$\mu$/ml). Chloroform fraction more strongly inhibited the platelet aggregation than the other two fraction among them. There were fatty acid ester and phosphate ester instead of polyacethylene compounds in the chloroform fraction.

• BMB Reports
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• 제40권5호
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• pp.678-683
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• 2007

Extracts from the leaves of the Ginkgo biloba are becoming increasingly popular as a treatment that is claimed to reduce atherosclerosis, coronary artery disease, and thrombosis. In this study, the effect of ginkgolide B (GB) from Ginkgo biloba leaves in collagen (10 ${\mu}g/ml$)-stimulated platelet aggregation was investigated. It has been known that human platelets release matrix metallo-proteinase-9 (MMP-9), and that it significantly inhibited platelet aggregation stimulated by collagen. Zymographic analysis confirmed that pro-MMP-9 (92-kDa) was activated by GB to form an MMP-9 (86-kDa) on gelatinolytic activities. And then, activated MMP-9 by GB dose-dependently inhibited platelet aggregation, intracellular $Ca^{2+}$ mobilization, and thromboxane $A_2$ ($TXA_2$) formation in collagen-stimulated platelets. Activated MMP-9 by GB directly affects down-regulations of cyclooxygenase-1 (COX-1) or $TXA_2$ synthase in a cell free system. In addition, activated MMP-9 significantly increased the formation of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), which have the anti-platelet function in resting and collagen-stimulated platelets. Therefore, we suggest that activated MMP-9 by GB may increase the intracellular cAMP and cGMP production, inhibit the intracellular $Ca^{2+}$ mobilization and $TXA_2$ production, thereby leading to inhibition of platelet aggregation. These results strongly indicate that activated MMP-9 is a potent inhibitor of collagen-stimulated platelet aggregation. It may act a crucial role as a negative regulator during platelet activation.