• 대한의생명과학회지
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• 제20권2호
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• pp.70-76
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• 2014

In this study, we investigated the effect of DMSO, a highly dipolar organic liquid, in collagen ($5{\mu}g/ml$)-stimulated platelet aggregation. DMSO inhibited platelet aggregation at 0.5% by inhibiting production of thromboxane $A_2$ ($TXA_2$) which was associated with blocking cyclooxygenase (COX)-1 activity and $TXA_2$ synthase. In addition, DMSO significantly increased the formation of cyclic adenosine monophosphate (cAMP) from adenosine triphosphate (ATP) and cyclic guanosine monophosphate (cGMP) from guanosine triphosphate (GTP). On the other hand, DMSO (0.1~0.5% concentration) did not affect the LDH release which indicates the cytotoxicity. Based on these results, DMSO has anti-platelet effect by regulation of several platelet signaling pathways, therefore we suggest that DMSO could be a novel strategy on many thrombotic disorders.

• 대한의생명과학회지
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• 제23권4호
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• pp.310-320
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• 2017

Ginseng has been widely used for traditional medicine in eastern Asia and is known to have inhibitory effects on cardiovascular disease (CVD) such as thrombosis, atherosclerosis, and myocardial infarction. Because, platelet is a crucial mediator of CVD, many studies are focusing on inhibitory mechanism of platelet functions. Among platelet activating molecules, thromboxane $A_2$ ($TXA_2$) and P-selectin play a central role in CVD. $TXA_2$ leads to intracellular signaling cascades and P-selectin plays an important role in platelet-neutrophil and platelet-monocyte interactions leading to the inflammatory response. In this study, we investigated the inhibitory mechanisms of total saponin fraction from Korean red ginseng (KRG-TS) on $TXA_2$ production and P-selectin expression. Thrombin-elevated $TXA_2$ production and arachidonic acid release were decreased by KRG-TS dose (25 to $150{\mu}g/mL$)-dependently via down regulation of microsomal cyclooxygenase-1 (COX-1), $TXA_2$ synthase (TXAS) activity and dephosphorylation of cytosolic phospholipase $A_2$ ($cPLA_2$). In addition, KRG-TS suppressed thrombin-activated P-selectin expression, an indicator of granule release via dephosphorylation of mitogen-activated protein kinases (MAPK). Taken together, we revealed that KRG-TS is a beneficial novel compound inhibiting $TXA_2$ production and P-selectin expression, which may prevent platelet aggregation-mediated thrombotic disease.

• Journal of Ginseng Research
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• 제43권2호
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• pp.236-241
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• 2019

Background: Thromboxane A2 ($TXA_2$) induces platelet aggregation and promotes thrombus formation. Although ginsenoside Ro (G-Ro) from Panax ginseng is known to exhibit a $Ca^{2+}-antagonistic$ antiplatelet effect, whether it inhibits $Ca^{2+}-dependent$ cytosolic phospholipase $A_2$ ($cPLA_{2{\alpha}}$) activity to prevent the release of arachidonic acid (AA), a $TXA_2$ precursor, is unknown. In this study, we attempted to identify the mechanism underlying G-Ro-mediated $TXA_2$ inhibition. Methods: We investigated whether G-Ro attenuates $TXA_2$ production and its associated molecules, such as cyclooxygenase-1 (COX-1), $TXA_2$ synthase (TXAS), $cPLA_{2{\alpha}}$, mitogen-activated protein kinases, and AA. To assay COX-1 and TXAS, we used microsomal fraction of platelets. Results: G-Ro reduced $TXA_2$ production by inhibiting AA release. It acted by decreasing the phosphorylation of $cPLA_{2{\alpha}}$, p38-mitogen-activated protein kinase, and c-Jun N-terminal kinase1, rather than by inhibiting COX-1 and TXAS in thrombin-activated human platelets. Conclusion: G-Ro inhibits AA release to attenuate $TXA_2$ production, which may counteract $TXA_2-associated$ thrombosis.

• Journal of Applied Biological Chemistry
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• 제66권
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• pp.455-461
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• 2023

Glycyrrhiza glabra is a well-known medicinal herb that grows in various parts of the world and glabridin is a major chemical compound that is found in the root extract of Glycyrrhiza glabra. Glabridin is a natural compound known to have antioxidant, anti-inflammatory, anti-atherogenic, anti-osteoporotic and skin-whitening. In this study, we investigated if glabridin inhibited platelet aggregation and thrombus formation. We observed that glabridin inhibited collagen-induced platelet aggregation and suppressed signal transduction molecules such as phosphatidylinositol-3 kinase (PI₃K), Akt, glycogen synthase kinase-3α/β (GSK-3α/β), SYK, cytosolic phospholipase A₂, and p38 expression. In addition, glabridin suppressed thromboxane A₂ generation and thrombin-induced clot retraction. Taken together, glabridin showed strong antiplatelet effects and may be used to block thrombosis- and platelet-mediated cardiovascular diseases.

• The Korean Journal of Physiology and Pharmacology
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• 제19권3호
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• pp.257-262
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• 2015

It is well known that cigarette smoke can cause erectile dysfunction by affecting the penile vascular system. However, the exact effects of nicotine on the corpus cavernosum remains poorly understood. Nicotine has been reported to cause relaxation of the corpus cavernosum; it has also been reported to cause both contraction and relaxation. Therefore, high concentrations of nicotine were studied in strips from the rabbit corpus cavernosum to better understand its effects. The proximal penile corpus cavernosal strips from male rabbits weighing approximately 4 kg were used in organ bath studies. Nicotine in high concentrations ($10^{-5}{\sim}10^{-4}M$) produced dose-dependent contractions of the corpus cavernosal strips. The incubation with $10^{-5}M$ hexamethonium (nicotinic receptor antagonist) significantly inhibited the magnitude of the nicotine associated contractions. The nicotine-induced contractions were not only significantly inhibited by pretreatment with $10^{-5}M$ indomethacin (nonspecific cyclooxygenase inhibitor) and with $10^{-6}M$ NS-398 (selective cyclooxygenase inhibitor), but also with $10^{-6}M$ Y-27632 (Rho kinase inhibitor). Ozagrel (thromboxane $A_2$ synthase inhibitor) and SQ-29548 (highly selective TP receptor antagonist) pretreatments significantly reduced the nicotine-induced contractile amplitude of the strips. High concentrations of nicotine caused contraction of isolated rabbit corpus cavernosal strips. This contraction appeared to be mediated by activation of nicotinic receptors. Rho-kinase and cyclooxygenase pathways, especially cyclooxygenase-2 and thromboxane $A_2$, might play a pivotal role in the mechanism associated with nicotine-induced contraction of the rabbit corpus cavernosum.

• Journal of Applied Biological Chemistry
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• 제66권
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• pp.236-243
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• 2023

혈소판은 1차 및 2차 지혈에서 근본적인 역할을 하는 세포지만 혈소판의 과도한 활성화는 혈전증을 유발할 수 있다. 따라서 혈소판 응집의 적절한 조절은 혈전증 매개 질환을 예방하는 데 중요하다. 최근 곤충소재의 개발이 주목을 받고 있다. 다양한 곤충 자원 중 고영양 기능성 식품원으로는 쌍별귀뚜라미(Gryllus bimaculatus)와 같은 곤충류가 있다. 쌍별귀뚜라미 는 고단백 및 불포화지방산을 함유하고 있으며 2015년 9월 식품의약품안전처로부터 식품원료로 등록되었다. 본 연구에서는 쌍별귀뚜라미 에탄올 추출물(G. bimaculatus extract)이 혈소판 응집, 세포 내 Ca²⁺ 조절, thromboxane A₂ 생산 및 glycoprotein IIb/IIIa (integrin αIIb/β3) 활성화를 억제하는지 여부를 확인하고. 1, 4, 5-triphosphate receptor type I, extracellular signal-regulated kinase, cytosolic phospholipase A₂, mitogen-activated protein kinases p38, vasodilator-stimulated phosphoprotein, phosphatidylinositol-3 kinase, Akt, glycogen synthase kinase-3α/β 및 SYK 같은 신호 분자를 조절할 수 있는지 여부를 조사했다. 우리는 쌍별귀뚜라미 추출물이 혈소판 관련 혈전증 및 심혈관 질환을 예방할 수 있는 잠재적인 치료 약물로 가치가 있음을 규명하였다.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2001년도 추계학술대회 및 정기총회
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• pp.94-94
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• 2001

Prostaglandin endoperoxide H synthase (PGHS) catalyzes the committed step in prostaglandins and thromboxane A$_2$-- oxygenation of arachidonic acid to the hydroperoxy endoperoxide PGG$_2$, followed by reduction PGG$_2$to the alcohol PGH$_2$. The two reactions by PGHS -- cyclooxygenase and peroxidase -- occur at distinct but structurally and functionally interconnected sites. The peroxidase reaction occurs at a heme-containing active site located near the protein surface. The cyclooxygenase reaction occurs in a hydrophobic channel in the core of the enzyme. Initially a peroxide reacts with the heme group, yielding Compound I and an alcohol derived from the oxidizing peroxide. Compound I next undergoes an intramolecular reduction by a single electron traveling from Tyr385 along the peptide chain to the proximal heme ligand, His388, and finally to the heme group. Following the binding of arachidonic acid, Tyr385 tyrosyl radical initiates the cyclooxygenase reaction by abstracting the 13-pro(5) hydrogen atom to give an arachidonyl radical, which sequentially reacts with two molecules of oxygen to yield PGG$_2$. In order to characterize PGHS peroxidase active site, we examined various lipid peroxides with purified recombinant ovine PGHS proteins and determined the rate constants. The results have shown that twenty-carbon unsaturated fatty acid hydroperoxides have similar efficiency in peroxidation by PGHS, irrespective of either the location of hydroperoxy group or the number of double bonds. It was also confirmed by the subsequent study with PGHS peroxidase active site mutants.

• Journal of Ginseng Research
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• 제32권2호
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• pp.89-98
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• 2008

There are increasing evidences in the literatures on the potential role of ginsenosides in treating cardiovascular diseases. In this article, current information about ginsenosides-mediated vascular relaxation are reviewed. From the published studies using isolated organs, cell culture systems and animal models, ginsenosides are shown to relax blood vessels and improve blood flow through diverse mechanisms, including nitric oxide release by activating eNOS phosphorylation via PI3K/Akt and/or ERK1/2 pathways in endothelial cells, induction of inducible nitric oxide synthase through activation of NF-${\kappa}$B, reducing the intracelluar Ca$^{2+}$ levels by activating Ca$^{2+}$-activated K$^{+}$ channels in vascular smooth muscle cells and reducing platelet aggregation by decreasing thromboxane A$_2$ formation and intracelluar Ca$^{2+}$in platelets. In addition, the relevant clinical trials regarding the effects of ginsenosides on the cardiovascular disease are summarized, particulary focusing on managing hypertension and improving thrombotic disorders. Finally, antagonistic effects of ginsenosides on the prostaglandin H$_2$ receptor and scavenging effects on the generation of oxygen-derived free radicals in spontaneously hypertensive rats (SHR) are discussed.

• 대한임상검사과학회지
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• 제49권2호
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• pp.99-107
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• 2017

진균 속에 속하는 종인 Cordyceps는 중국의 전통약제로서, 그 유효성분인 cordycepin이 혈소판 응집에 관여한다는 보고가 있지만 phosphoprotein 조절에 관련된 연구는 미흡하다. 본 연구에서는, cordycepin이 fibrinogen binding에 관여한다고 알려진 PI3k/Akt와 $TXA_2$ 분비 및 과립방출에 관여한다고 알려진 p38와 같은 phosphoprotein의 인산화를 어떻게 조절하며 혈소판응집을 억제시키는지 규명하고자 하였다. 그 결과, cordycepin가 $261.1{\mu}M$의 $IC_{50}$으로 collagen이 유도한 혈소판 응집을 강력하게 억제하였고, PI3K와 Akt의 인산화를 감소시키며 ${\alpha}IIb/{\beta}_3$에 대한 fibrinogen 결합을 농도의존적으로 억제하였다. 또한, cordycepin은 collagen이 촉진시킨 p38의 인산화를 억제함으로써, 과립방출의 지표인 ATP 과 serotonin의 방출을 억제하였고 COX-1과 TXAS의 활성 및 $PLC-{\gamma}_2$ 인산화에 대한 영향없이 $TXA_2$ 생성량을 감소시켰다. 따라서, cordycepin은 PI3K/Akt, p38와 같은 phosphoprotein의 인산화를 억제함으로써 혈소판 응집억제를 나타내는 항혈전 치료 및 예방약물로서 유용한 가치가 있다고 여겨진다.

• 동의생리병리학회지
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• 제19권5호
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• pp.1391-1398
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• 2005

The anti-thrombic properties of the oriental herbal medicine Daejowhan(DJW, 大造丸) which consists of 11 kinds of herbs (indicated as ratio) of Rehmanniae Radix 24%, Hominis Placenta 5%, Testudinis Carapax 9%, Eucommiae Cortex 9%, Asparagi Radix 9%, Phellodendri Cortex 9%, Achyranthis Radix 7%, Liriopis Tuber 7%, Angelicae Sinensis Radix 7%, Ginseng Radix 5% and Schizandrae Fructus 3% were investigated. The water extracts from DJW inhibited Platelet-activating factor(PAF) induced platelet aggregation. DJW was extracted with methanol and further fractionated by ethylacetate. A 70% methanol extract showed a strong inhibition against PAF-induced aggregation in vitro and in vivo assays. The ethylacetate soluble fraction was shown to have inhibitory effect on PAF-induced platelet aggregation in vitro assay. The ethylacetate soluble fraction specially protected against the lethality of PAF, while verapamil did not afford any protection. These results indicate that the water extracts and alcoholic-fractions inhibit the action of PAF in vivo by an antagonistic effect on PAF, so that it may be useful in treating disorders caused by PAF, such as acute allergy, inflammation, asthma, gastrointestinal ulceration, toxic shock and so forth. DJW was investigated regarding its assumed anti-thrombic action on human platelets which was deduced from its ability to suppress Arachidonic acid(AA)-induced aggregation, exocytosis of ATP, and inhibition of Cyclooxygenase(COX) and Thromboxane synthase(TXS) activity. The latter two effects were estimated from the generation of Prostaglandin $E_2(PGE_2)$ and Thromboxane $A_2(TXA_2)$ respectively. Exogenously applied AA ($100{\mu}mol/{\ell}$) provoked a $89\%$ aggregation of platelets, the release of 14 pmol ATP, and the formation of either 225 pg $TXA_2$ or 45 pg $PGE_2$, each parameter being related to 106 platelets. An application of DJW 5 min before AA dose-dependently diminished aggregation, ATP-release and the synthesis of $TXA_2$ and $PGE_2$ with $IC_{50}$ values of 74, 108, 65, $72{\mu}g/m{\ell}$, respectively. The similarity of the $IC_{50}$ values suggest an inhibition of COX by DJW as primary target, thus suppressing the generation of $TXA_2$ which induces aggregation of platelets and exocytosis of ATP by its binding on $TXA_2$-receptors.