• YAKHAK HOEJI
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• v.58 no.4
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• pp.223-228
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• 2014

The present study was undertaken to investigate the influence of sulforaphane on vascular smooth muscle contractility and to determine the mechanism involved. We hypothesized that sulforaphane, the primary ingredient of broccoli of cruciferous vegetables, plays a role in vascular relaxation through inhibition of Rho-kinase in rat aortae. Intact of denuded arterial rings from male Sprague-Dawley rats were used and isometric tensions were recorded using a computerized data acquisition system. Interestingly, sulforaphane significantly inhibited fluoride, phorbol ester or thromboxane $A_2$ mimetic-induced contraction in denuded muscles suggesting that additional pathways different from endothelial nitric oxide synthesis such as inhibition of Rho-kinase or MEK might be involved in the vasorelaxation. Furthermore, sulforaphane inhibited thromboxane $A_2$-induced increases in pERK1/2 levels suggesting the mechanism including inhibition of thromboxane $A_2$-induced increases in ERK1/2 phosphorylation. This study provides evidence that sulforaphane induces vascular relaxation through inhibition of Rho-kinase or MEK in rat aortae.

• YAKHAK HOEJI
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• v.50 no.4
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• pp.293-299
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• 2006

The aim of present study was to investigate the possible influence of Rho-kinase inhibition on the plant-derived estrogen-like compounds-induced arterial relaxation. Agonist- or depolarization-induced vascular smooth muscle contractions involve the activation of Rho-kinase pathway. However there are no reports addressing the question whether this pathway is involved in genistein-or daidzein-induced vascular relaxation in rat aortae precontracted with phenylephrine or thromboxane $A_2$ mimetic U-46619. We hypothesized that Rho-kinase inhibition plays a role in vascular relaxation evoked by genistein or daidzein in rat aortae. Endothelium-intact and denuded arterial rings from male Sprague-Dawley rats were used and isometric contractions were recorded using a computerized data acquisition system. Genistein concentration-dependently inhibited phenylephrine or thromboxane $A_2-induced$ contraction regardless of endothelial function. Surprisingly, in the agonists-induced contraction, similar results were also observed in aortae treated with daidzein, the inactive congener for protein tyrosine kinase inhibition, suggesting that Rho-kinase might act upstream of tyrosine kinases in phenylephrine-induced contraction. In conclusion, in the agonists-precontracted rat aortae, genistein and daidzein showed similar relaxant response regardless of tyrosine kinase inhibition or endothelial function.

• Journal of Ginseng Research
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• v.18 no.1
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• pp.44-48
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• 1994

In adrenaline-stimulated human platelets, panaxadiol (PD) and panaxatriol (PT) from Panax ginseng C.A. Meyer did not inhibit the $Ca^{2+}$-innux, but inhibited the formation of thromboxane $A_2$ and the platelet aggregations. It seems that PD and PT block a pathyway interconvefing arachidonic acids (20:4) to thromboxane $A_2$ (TX $A_2$), because the amount of $Ca^{2+}$ which phospholipase C or phospholipase $A_2$ requires to liberate 20 : 4 from membrane phospholipids was increased by PD and PT. These results mean that PH and PT have an antiplatelet effect by Inhibiting the formation of TX $A_2$.

• YAKHAK HOEJI
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• v.58 no.5
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• pp.337-342
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• 2014

The present study was undertaken to investigate the influence of diosgenin on vascular smooth muscle contractility and to determine the mechanism involved. We hypothesized that diosgenin, the primary ingredient of Dioscorea villosa, plays a role in vascular relaxation through inhibition of Rho-kinase in rat aortae. Denuded arterial rings from male Sprague-Dawley rats were used and isometric tensions were recorded using a computerized data acquisition system. Interestingly, diosgenin inhibited fluoride-induced contraction but didn't inhibit phorbol ester-induced contraction suggesting that additional pathways different from endothelial nitric oxide synthesis such as inhibition of Rho-kinase might be involved in the vasorelaxation. Furthermore, diosgenin didn't inhibit thromboxane $A_2$-induced increases in pERK1/2 levels suggesting the mechanism excluding inhibition of thromboxane $A_2$-induced increases in ERK1/2 phosphorylation. This study provides evidence that diosgenin induces vascular relaxation through inhibition of Rho-kinase in rat aortae.

• The Korea Journal of Herbology
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• v.26 no.4
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• pp.139-147
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• 2011

Objectives : The aim of this study is to research an anti-thrombus effect by Diospyros Kaki Calyx. Methods : The healthy human plasma were gained and used in vitro study such as factor X activity (FXa) inhibition, prothrombinase inhibition, prothrombin time (PT) and activated partial thromboplastin time. Fifteen SD rats were divided into three groups ; intact control group (orally administrated with distilled water 5ml/kg) and two experimental group treated with extract of diospyros kaki calyx (EKC). Experimental rats were orally 600 mg/kg concentration of EKC and 200 mg/kg concentration of EKC. After an hour from administration, we anesthetized rats and made arteriovenous (AV) shunt rat models to study weight of thrombus, took whole blood to study content of thromboxane B2 and blood clotting time. Results : In vitro, EKC significantly increased inhibitory activity of FXa, prothrombinase compared with intact control group ($^*P$ <0.05). PT and aPTT were increased in EKC treated (600 mg/kg) group compared with intact control group ($^*P$ <0.05). In vivo, blood clotting time of experiment group treated with EKC 600 mg/kg were significantly increased compare with that of intact control group (p<0.05) and content of thromboxane B2 was significantly decreased in group treated with EKC 600 mg/kg in serum. The weight of thrombus were significantly reduced in group treated with EKC 600 mg/kg compared with intact control group (p<0.05). But in vivo experiment study, those parameters of group treated with EKC 200 mg/kg were relatively decreased compared with those of intact control group without statistical significance. Conclusions : EKC has an antithrombic activity because of inhibition internal course such as FXa and prothrombin. And EKC inhibited a hole blood clotting in vivo experiment by low content of thromboxane B2.

• KSBB Journal
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• v.28 no.1
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• pp.7-12
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• 2013

Thromboxane $A_2$ ($TXA_2$) is one of major proinflammatory mediators, plays an important role in the development of vascular inflammatory diseases. $TXA_2$ acting through the thromboxane receptor regulates multiple pathways and genes in a variety of cells. In this study, we report that the activation of thromboxane receptor with U46619 increases the interleukin-8 (IL-8) mRNA in vascular endothelial cells. We also demonstrated that U46619 produces the activations of extracellular signal-regulated kinase 1/2 (ERK1/2) and p38 mitogen-activated protein kinase (MAPK), which is required for endothelial IL-8 production. And U46619 enhanced mRNA stability of IL-8 transcripts in endothelial cells. Moreover, inhibition of ERK1/2 or p38MAPK reduced monocyte adhesion to aortic endothelium stimulated by U46619. Therefore, these results suggest that activation of thromboxane receptor promotes the expression of IL-8 via ERK1/2 and p38MAPK activation in endothelial cells.

• Molecules and Cells
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• v.27 no.2
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• pp.191-198
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• 2009

The present study was undertaken to determine whether treatment with genistein, the plant-derived estrogen-like compound influences agonist-induced vascular smooth muscle contraction and, if so, to investigate related mechanisms. The measurement of isometric contractions using a computerized data acquisition system was combined with molecular experiments. Genistein completely inhibited KCl-, phorbol ester-, phenylephrine-, fluoride- and thromboxane $A_2$-induced contractions. An inactive analogue, daidzein, completely inhibited only fluoride-induced contraction regardless of endothelial function, suggesting some difference between the mechanisms of RhoA/Rho-kinase activators such as fluoride and thromboxane $A_2$. Furthermore, genistein and daidzein each significantly decreased phosphorylation of MYPT1 at Thr855 had been induced by a thromboxane $A_2$ mimetic. Interestingly, iberiotoxin, a blocker of large-conductance calcium-activated potassium channels, did not inhibit the relaxation response to genistein or daidzein in denuded aortic rings precontracted with fluoride. In conclusion, genistein or daidzein elicit similar relaxing responses in fluoride-induced contractions, regardless of tyrosine kinase inhibition or endothelial function, and the relaxation caused by genistein or daidzein was not antagonized by large conductance $K_{Ca}$-channel inhibitors in the denuded muscle. This suggests that the RhoA/Rho-kinase pathway rather than $K^+$- channels are involved in the genistein-induced vasodilation. In addition, based on molecular and physiological results, only one vasoconstrictor fluoride seems to be a full RhoA/Rho-kinase activator; the others are partial activators.

• Biomolecules & Therapeutics
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• v.20 no.3
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• pp.352-356
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• 2012

The present study was undertaken to determine whether ethanol influences on the agonist-induced vascular smooth muscle contraction and, if so, to investigate the related mechanism. The measurement of isometric contractions using a computerized data acquisition system was combined with molecular experiments. Ethanol significantly inhibited thromboxane $A_2$ mimetic-induced contraction with intact endothelial function, but there was no relaxation on thromboxane $A_2$ mimetic U-46619-induced contraction irrespective of endothelium suggesting that the pathway such as Rho-kinase activation, $Ca^{2+}$ entry or thin filament regulation was not affected. In addition, ethanol didn't decrease thromboxane $A_2$ mimetic-induced increase of phospho-myosin phosphatase targeting subunit protein 1 (pMYPT1) or pERK1/2. Interestingly, ethanol didn't inhibit significantly phorbol ester-induced contraction in denuded muscles suggesting that thin filament regulation is less important on the ethanol-induced regulation in the muscle than endothelial NO synthesis. In conclusion, this study provides the evidence and possible related mechanism concerning the effect of ethanol on the agonist-dependent contraction in rat aortic rings with regard to endothelial function.

• The Korea Journal of Herbology
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• v.26 no.4
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• pp.125-132
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• 2011

Objectives : An aim of study is to investigate effects of curculiginis rhizoma in vitro (factor Xa (FXa) inhibitor assay, prothrombinase assay, prothrombin time (PT) assay, activated partial thromboplastin time (aPTT) assay) and in vivo experiment (blood clotting time, thromboxane B2 content assay in serum and weight of thrombus by AV-shunt rat model). Methods : We gained a human serum and used serum in vitro study such as factor X activity (FXa) inhibition, prothrombinase inhibition, prothrombin time (PT) and activated partial thromboplastin time. Fifteen SD rats were divided into three groups (intact control group and two experimental group treated with extract of Curculiginis Rhizoma(ECR)). Rats were orally administrated DW (intact control group), 600 mg/kg concertration of ECR and 200 mg/kg concertration of ECR. After one hour, we anesthetized rats and made arteriovenous (AV) shunt rat models to study weights of thrombus, took a hole blood to study content of thromboxane B2 and blood clotting time. Results : In vitro, ECR increased a inhibitory activity of FXa, prothrombinase and aPTT compared than intact control group. Especially ECR made significant increase of FXa and prothrombinase inhibitory activity (p<0.05, p<0.01). And PT were increased in ECR control group compared with intact control group. In vivo, a blood clotting time of experiment group treated with ECR 600 mg/kg were significantly increased compared with that of intact control group (p<0.05) and content of thromboxane B2 was significantly decreased in group treated with ECR 600 mg/kg in seum. The weight of thrombus were significantly reduced in group treated with ECR 600 mg/kg compared with intact control group (p<0.05). But in vivo experiment study, those of group treated with ECR 200 mg/kg were reduced compared with those of intact control group without statistical significance. Conclusions : ECR has a antithromboic activity in internal course with inhibitory activity of FXa and prothrombinase in vitro, it required to research more study for effective compounds.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.114-121
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• 2023

Selective cyclooxygenase (COX)-2 inhibition is a novel strategy to reduce the risk of gastrointestinal side effects caused by conventional nonsteroidal anti-inflammatory drugs. However, some selective COX-2 inhibitors have become apparent to increase the risk of severe cardiovascular disease. The aim of this study was to examine the anti-inflammatory effect of rosemary extract (RE) and confirm the safety of cardiovascular side effects. Inhibition of COX enzyme activity was assessed, and the levels of COX-2 and prostaglandin E₂ (PGE₂) and COX-1 and thromboxane B₂ (TXB₂) were evaluated in lipopolysaccharide (LPS)-induced RAW 264.7 cells. The 40% RE group showed increased COX-2 inhibition activity in a dose-dependent manner, whereas the 50% RE group only exhibited at 100 ㎍/mL. In a cell-based study, COX-2 mRNA expression was similar in both RE groups and PGE₂ levels tended to decrease in the 40% RE group compared to the LPS group in the LPS pretreatment condition. In the LPS posttreatment condition, the COX-2 mRNA expression decreased in the 40% RE group, and PGE₂ levels were increased in the 40 and 50% RE groups. In both conditions, there was no significant difference in COX-1 and TXB₂ levels. In conclusion, 40 and 50% RE showed significant COX-2 inhibition, similar to the positive control group. It was confirmed that the inhibition of the COX-2 expression, but the effect did not affect the balance between prostacyclin and TXB₂. These results indicate that rosemary showed COX-2 inhibition activity with a low risk of cardiovascular diseases.