• Journal of Applied Biological Chemistry
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• 제66권
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• pp.122-127
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• 2023

심혈관 질환(CVD)은 전 세계적으로 주요 사망 원인으로써 갈수록 증가하는 추세이며, 혈관 손상이 발생하였을 때, 혈전이 과도하게 형성되는 것이 그 원인인 중 하나이다. 근래에 혈소판 억제를 통한 항혈전 물질에 대한 관심이 커지고 있으며 천연 생물활성 화합물을 사용함으로써 부작용을 줄이려는 노력이 이루어지고 있다. Flavonoid 중 하나로 알려진 hydroxygenkwanin(HGK)은 팥꽃나무(Daphne genkwa)에서 정제되는 물질로서 항균, 항염증 및 항암 효과가 있다고 알려져 있으며, 혈전증을 예방하는 조직 인자의 억제제 역할을 한다고 보고되었지만 항혈소판 효과와 그 작용기전에 대해서는 거의 알려지지 않았다. 본 연구를 통해 HGK가 collagen 유도의 사람 혈소판 응집에 미치는지 확인하였고, 그 작용 기전을 확인하였다. HGK은 혈소판 신호 전달 과정에서 PI3K/AKT 및 MAPK의 인산화를 억제하였고, ATP 및 serotonin 등의 혈소판 내 과립 분비를 감소하였다. . 또한, HGK는 cPLA₂의 인산화를 억제하며 응집 촉진물질인 TXA₂ 생성을 강하게 저해하였다. 결과적으로 응집 유도 물질인 collagen가 유도한 혈소판 응집을 86.36 µM의 IC₅₀로 강하게 억제하였다. 그러므로, 본 연구를 통해 HGK가 혈관 손상을 통해 일어나는 사람 혈소판의 활성화 및 응집을 억제하는 항혈전 물질로 가치가 있음을 분명히 하였다.

• 한국버섯학회지
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• 제15권3호
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• pp.124-128
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• 2017

국내 상황버섯 재배 종인 Phellinus baumii (PB, Jangsu sanghwang), P. linteus (PLK, Korea Sangwhang), 그리고 P. linteus HN00k9 (PLH) 자실체의 methanol 추출물의 혈소판 응집 억제와 ATP release 감소효과를 조사하였다. PB, PLK, PLH methanol 추출물을 전 처리하고 혈소판 응집촉진물인 collagen (2.5 ug/ml), ADP (10 uM), thrombin (0.1 U/ml) 처리에 50ug/ml에서 200 ug/ml 농도에서 50%에서 95%의 혈소판응집억제 효과가 나타났으며 ATP release 감소효과는 200 ug/ml 농도에서 ADP(10 uM) 처리 혈소판에서 60%에서 50%로 나타났으며 이는 Phospholipase C의 inhibitor인 U73122 (4 uM)과 calcium chelator인 EDTA (1 mM)에 비하여 20%이상 높게 나타났다. 본 결과로부터 상황버섯 PB, PLK, PLH 메탄올 추출물은 심혈관계질병을 예방 하는 유용한 소재로 활용 가능 할 것으로 사료 된다.

• BMB Reports
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• 제44권2호
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• pp.140-145
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• 2011

Impaired responsiveness of platelets to epinephrine (epi) and other catecholamines (CA) has been reported in approximately 20% of the healthy Korean and Japanese populations. In the present study, platelet aggregation induced by epi was potentiated by RO 31-8220 (RO) or G$\ddot{o}$ 6983 (G$\ddot{o}$). Phosphorylated Akt (p-Akt) was very low in epi-stimulated PRP from CA-hypo- responders (CA-HY), whereas it was detected in those from CA-good responders (CA-GR). RO and G$\ddot{o}$ increased p-Akt, one of the major downstream effectors of phosphoinositol-3 kinase (PI3K), in epi-stimulated PRP from both groups. Wortmannin, a PI3K inhibitor, attenuated the RO or G$\ddot{o}$-induced potentiation of p-Akt in epi-stimulated PRP, suggesting positive effects for RO and G$\ddot{o}$ on PI3K. $TXA_2$ formation was increased by the addition of either RO or G$\ddot{o}$ in epi-stimulated platelets. The present data also suggest that impaired Akt phosphorylation may be responsible for epinephrine hypo-responsiveness of platelets.

• Nutrition Research and Practice
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• 제2권4호
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• pp.211-217
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• 2008

This study was purposed to investigate the effect of onion or beet on plasma and liver lipids, erythrocyte Na efflux channels and platelet aggregation in simvastatin (SIM) treated hypercholesterolemic rats. Forty Sprague Dawley rats were divided into four groups and fed 0.5% cholesterol based diets containing 2 mg/kg BW simvastatin or simvastatin with 5% onion or beet powder. Plasma total cholesterol was significantly increased in SIM group compared with the control (p<0.01), and the elevated plasma total cholesterol of SIM group was significantly decreased in SIM-onion and SIM-beet groups (p<0.05). HDL-cholesterol in SIM-beet group was significantly increased compared with other groups (p<0.05). Platelet aggregation in both the maximum and initial slope was significantly decreased in SIM group compared with SIM-onion group (p<0.05). Na-K ATPase was significantly decreased in SIM group compared with the control, SIM-onion and SIM-beet groups (p<0.05). Na passive leak was significantly increased in all groups treated with SIM compared with the control (p<0.05). The total Na efflux was decreased in SIM group and increased in SIM-onion group and the difference between these two groups was significant (p<0.05). There was no difference in intracellular Na among groups. In present study, simvastatin, a HMG CoA reductase inhibitor at dose of 2mg/kg BW/day rather increased plasma total cholesterol in rats, inferring that the action mechanism of simvastatin on cholesterol metabolism differ between rat and human. Onion and beet play favorable roles in cardiovascular system by restoring the reduced Na efflux through Na-K ATPase and Na-K cotransport in SIM treated rats.

• Biomolecules & Therapeutics
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• 제3권2호
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• pp.104-110
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• 1995

Arachidonic acid (AA, C20 : 4, $\omega$-6) and eicosapentanoic acid (EPA,C20 : 5, $\omega$-3), which are polyunsaturated fatty acids forming eicosanoids, were tested for their effects on blood pressure in Wistar rats and SHR. AA is the most important precursor for the biosynthesis of eicosanoids which include the prostaglandins, prostacyclin (PGI$_2$), thromboxane $A_2$ (TXA$_2$) and the leukotriens. TXA$_2$is a potent vasoconstrictor and a powerful inducer of platelet aggregation causing myocardial infarction and hypertention. In contrast, PGI$_2$ induces vasodilation and inhibits platelet aggregation. In this study, AA markedly increased blood pressure, but its effect was antagonized by both EPA, a structural analog of AA, and dazmegrel, a TX synthetase inhibitor. Also, AA enhanced the antihypertensive effects of hydralazine and captopril, and EPA reduced TXA$_2$ production. These results indicate that the hypotensive effects of EPA might be closely related to the decrease in TXA$_2$ biosynthesis due to competitive inhibition by structural similarity of the EPA to the AA, the precursor of TXA$_2$.

• Biomolecules & Therapeutics
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• 제9권2호
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• pp.69-78
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• 2001

Cyclooxygenase (COX) is an enzyme, which catalyzes the production of prostaglandins from arachi-donic acid and exists in two isoforms (COX-1 and COX-2). COX-1 is involved in the maintenance of physiological functions such as platelet aggregation, cytoprotection in the stomach and maintenance of normal kidney function. COX-2 is induced significantly in vivo under inflammatory conditions. COX-1 and COX-2 serve different physiological and pathological functions. All commercially available nonsteroidal antiinflammatory drugs (NSAIDS) are inhibitors of both COX-1 and COX-2. Therefore, selective inhibitors of COX-2 may be effective antiinflammatory agents without the ulcerogenic effects associated with current NSAms. Since the mid 1990s, a number of reports have been appeared on the preparation and biological activity of selective COX-2 inhibitors. Recently celecoxib, and rofecoxib, the representative COX-2 inhibitors, are introduced in the drug market. In this paper the relationship of structure-activity for selective COX-2 inhibitors is reviewed.

• 대한의생명과학회지
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• 제23권3호
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• pp.251-260
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• 2017

Platelet activation is essential at the sites of vascular injury, which leads to hemostasis through adhesion, aggregation, and secretion process. However, potent and continuous platelet activation may be an important reason of circulatory disorders. Therefore, proper regulation of platelet activation may be an effective treatment for vascular diseases. In this research, inhibitory effects of cordycepin (3'-deoxyadenosine) on platelet activation were determined. As the results, cordycepin increased cAMP and cGMP, which are intracellular $Ca^{2+}$-antagonists. In addition, cordycepin reduced collagen-elevated $[Ca^{2+}]_i$ mobilization, which was increased by a cAMP-dependent protein kinase (PKA) inhibitor (Rp-8-Br-cAMPS), but not a cGMP-protein kinase (PKG) inhibitor (Rp-8-Br-cGMPS). Furthermore, cordycepin increased $IP_3RI$ ($Ser^{1756}$) phosphorylation, indicating inhibition of $IP_3$-mediated $Ca^{2+}$ release from internal store via the $IP_3RI$, which was strongly inhibited by Rp-8-Br-cAMPS, but was not so much inhibited by Rp-8-Br-cGMPS. These results suggest that the reduction of $[Ca^{2+}]_i$ mobilization is caused by the cAMP/A-kinase-dependent $IP_3RI$ ($Ser^{1756}$) phosphorylation. In addition, cordycepin increased the phosphorylation of VASP ($Ser^{157}$) known as PKA substrate, but not VASP ($Ser^{239}$) known as PKG substrate. Cordycepin-induced VASP ($Ser^{157}$) phosphorylation was inhibited by Rp-8-Br-cAMPS, but was not inhibited by Rp-8-Br-cGMPS, and cordycepin inhibited collagen-induced fibrinogen binding to ${\alpha}IIb/{\beta}_3$, which was increased by Rp-8-Br-cAMPS, but was not inhibited by Rp-8-Br-cGMPS. These results suggest that the inhibition of ${\alpha}IIb/{\beta}_3$ activation is caused by the cAMP/A-kinase-dependent VASP ($Ser^{157}$) phosphorylation. In conclusion, these results demonstrate that inhibitory effects of cordycepin on platelet activation were due to inhibition of $[Ca^{2+}]_i$ mobilization through cAMP-dependent $IP_3RI$ ($Ser^{1756}$) phosphorylation and suppression of ${\alpha}IIb/{\beta}_3$ activation through cAMP-dependent VASP ($Ser^{157}$) phosphorylation. These results strongly indicated that cordycepin might have therapeutic or preventive potential for platelet activation-mediated disorders including thrombosis, atherosclerosis, myocardial infarction, or cardiovascular disease.

• 한국식품영양과학회지
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• 제35권8호
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• pp.979-984
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• 2006

과잉 철은 폐경기 여성 및 핀란드 남성에서의 심혈관계질환 증가와 예방통계학적으로 밀접한 관련이 있다고 보고되고 있다. 허혈성 심장질환, 뇌 심혈관계 질환, 암 및 노화의 원인으로 산화적 스트레스가 자유기 반응을 자극하고 지질 과산화 반응 등을 연쇄적으로 촉진시키는데 철이 위험 인자로 인식되고 있다. 그러나 뇌심혈관계 질환 유발의 중요인자인 혈소판 활성화와 관련하여 철로 인한 산화적 스트레스와 항산화작용의 연구는 부족하다고 한다. 산화적 스트레스에서 철 및 과산화수소의 자유기 형성과 관련하여 토끼 혈액에서 분리한 세정 혈소판을 사용하여 연구하였다. 산화적 스트레스를 통해 혈소판 응집을 유도하고 이에 미치는 영향을 연구한 결과에서 $H_2O_2$ 단독 투여시 혈소판 응집작용은 나타나지 않았다. $FeSO_4$ 단독 투여시 농도 의존적으로 혈소판 응집작용이 증가하여 나타내지만, $H_2O_2$ 존재 하에 $FeSO_4$ 투여시 농도 의존적으로 혈소판 응집작용이 증가되어 나타났다. 혈소판 응집을 유도하는 collagen 최적의 농도$(2\;{\mu}g/mL)$보다 낮은 1/10 농도$(2\;{\mu}g/mL)$)에서 $H_2O_2$ 및 $FeSO_4$의 영향은 농도 의존적으로 혈소판 응집작용이 증가되었다. 철 단독 투여시보다 과산화수소와 함께 투여시 농도 의존적으로 혈소판 활성화가 증대되었고 이러한 혈소판 활성화는 NAD/NADP, catalase, glutathione, mannitol, tiron 등에 의해 농도 의존적으로 억제되었고, NADH/NADPH, SOD, aspirin 등에 의해서는 영향이 없었다. 그러므로, 이러한 NAD(H)/NADP(H) cofactor는 혈소판 응집작용을 일으키는 radical을 직접 억제하기보다 radical 생성에 관련하는 것으로 사료된다. 이상의 결과에서 과잉철은 혈소판 활성화에 직접적으로 관여하고 $H_2O_2$ 존재하에 2가 철을 촉매로 하여 Fenton 반응으로 생성된 OH. 자유기가 혈소판 활성화에 중요한 역할을 한다. 그러나 혈소판에서 자유기가 arachidonic acid 대사의 활성화와 인산화 단백질로 인한 세포내 정보전달에 관한 연구가 더 이루어져야 한다고 사료된다.

• Biomolecules & Therapeutics
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• 제22권3호
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• pp.223-231
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• 2014

In this study, we prepared cordycepin-enriched (CE)-WIB801C, a n-butanol extract of Cordyceps militaris-hypha, and investigated the effect of CE-WIB801C on collagen-induced human platelet aggregation. CE-WIB801C dose-dependently inhibited collagen-induced platelet aggregation, and its $IC_{50}$ value was $175{\mu}g/ml$. CE-WIB801C increased cAMP level more than cGMP level, but inhibited collagen-elevated $[CA^{2+}]_i$ mobilization and thromboxane $A_2$ ($TXA_2$) production. cAMP-dependent protein kinase (A-kinase) inhibitor Rp-8-Br-cAMPS increased the CE-WIB801C-downregulated $[CA^{2+}]_i$ level in a dose dependent manner, and strongly inhibited CE-WIB801C-induced inositol 1, 4, 5-trisphosphate receptor ($IP_3R$) phosphorylation. These results suggest that the inhibition of $[CA^{2+}]_i$ mobilization by CE-WIB801C is resulted from the cAMP/A-kinase-dependent phosphorylation of $IP_3R$. CE-WIB801C suppressed $TXA_2$ production, but did not inhibit the activities of cyclooxygenase-1 (COX-1) and $TXA_2$ synthase (TXAS). These results suggest that the inhibition of $TXA_2$ production by WIB801C is not resulted from the direct inhibition of COX-1 and TXAS. In this study, we demonstrate that CE-WIB801C with cAMP-dependent $CA^{2+}$-antagonistic antiplatelet effects may have preventive or therapeutic potential for platelet aggregation-mediated diseases, such as thrombosis, myocardial infarction, atherosclerosis, and ischemic cerebrovascular disease.

• 한국임상약학회지
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• 제15권1호
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• pp.1-8
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• 2005

Clopidogrel is used to reduce the risk of cardiovascular events in patients with atherosclerosis documented by recent ischemic stroke, recent myocardial infarction (MI), or established peripheral arterial disease (secondary prevention). Clopidogrel is metabolized by CYP3A4, and the active metabolites inhibit platelet aggregation. The purpose of this study was to assess clopidogrel only versus clopidogrel + others (aspirin, CYP3A4 inhibitor, and CYPBA4 inducer) in terms of cardiovasculalr events and bleeding complications. We reviewed the charts of patients who visited between August 1, 2002 and August 31, 2003, retrospectively. Total 72 patients were included and they consisted of 5 groups; clopidogrel group (n=36), clopidogrel + aspirin group (n=11), clopidogrel + CYP3A4 inhibitor group (n=15), clopidogrel + aspirin + CYP3A4 inhibitor group (n=6), clopidorel + CYP3A4 inducer group (n=4). The primary endpoints at 6 months, 12 months were the composite of cardiovascular (CV) events. The secondary end-point was the incidence of bleeding events at 6months, and 12months. At 12months, the primary endpoint was not significantly different among the five groups (p=0.056). In comparison of two groups as clopidogrel only versus clopidogrel + others (aspirin, CYP3A4 inhibitor and CYP3A4 inducer), the primary endpoint was significantly different (p=0.02). The CV events were increased in the clopidogrel + others group. The secondary end point was not significantly different among the five groups (p=0.52). However, time to bleeding events was 230.8 in the clopidogrel group and 74.7 in the clopidogrel + others group (p = 0.046). In conclusion, clopidogrel interaction with aspirin, CYP3A4 inhibitor, and CYP3A4 inducer affected cardiovascular events and bleeding events. Drug interaction of clopidogrel with concurrent medications should be considered cautiously.