• Title/Summary/Keyword: Thromboxane A2

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Endothelium-Independent Effect of Fisetin on the Agonist-Induced Regulation of Vascular Contractility

  • Je, Hyun Dong;Sohn, Uy Dong;La, Hyen-Oh
    • Biomolecules & Therapeutics
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    • v.24 no.1
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    • pp.57-61
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    • 2016
  • Fisetin, a natural flavonoid found in a variety of vegetables and fruits, has been shown to possess many biological functions. The present study was undertaken to investigate the influence of fisetin on vascular smooth muscle contractility and to determine the mechanism involved. Denuded aortic rings from male rats were used and isometric contractions were recorded and combined with molecular experiments. Fisetin significantly relaxed fluoride-, thromboxane $A_2$- or phorbol ester-induced vascular contraction suggesting as a possible anti-hypertensive on the agonist-induced vascular contraction regardless of endothelial nitric oxide synthesis. Furthermore, fisetin significantly inhibited fluoride-induced increases in pMYPT1 levels and phorbol ester-induced increases in pERK1/2 levels suggesting the mechanism involving the inhibition of Rho-kinase activity and the subsequent phosphorylation of MYPT1 and MEK activity and the subsequent phosphorylation of ERK1/2. This study provides evidence regarding the mechanism underlying the relaxation effect of fisetin on agonist-induced vascular contraction regardless of endothelial function.

Ginsenosides Inhibit Endothelium - dependent Contraction in the Spontaneously Hypertensive Rat Aorta isn vitro (선천성 고혈압 랫드에서 ginsenosides에 의한 내피의존성수축의 억제작용)

  • 김낙두;최원선
    • Journal of Ginseng Research
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    • v.21 no.2
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    • pp.125-132
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    • 1997
  • Our previous study showed that in vivo treatment of spontaneously hypertensive rats (SHR) with protopanaxatriol ginsenosides (PPT) reduces the blood pressure and inhibits the con- tractions induced by endothelium-derived contracting factor (prostaglandin endoperoxide ($PGH_2$) and superoxide anion) in aorta isolated from SHR. The aim of the present study is to examine whether PPT improves endothelial functions in the isolated thoracic aorta of SHR in vitro. Treatments of aortic rings with PPT, purified ginsenoside $Rg_1$ ($Rg_1$) or indomethacin normalized endotheliuln-dependent relaxation to acetylcholine, but not with protopanaxadiol ginsenosides (PPD) and purified ginsenoside Rb1 (Rb1). The effects of PPT were dose-dependent. PGH,- and oxygen free radical-inducted contractions in rat aorta without endothelium were inhibited by PPT or $Rg_1$, but not by PPD or $Rb_1$. Contractions induced by PGF2$\alpha$, U-46619, a stable thromboxane A2 agonist or KCI (60 mM) were not inhibited by PPT, $Rg_1$ or $Rb_1$. These findings demonstrate that PPT but not PPD scavenges the oxygen-derived free radicals and/or antagonize the effects of $PGH_2$ in the vascular smooth muscle and may explain the hypotensive effect of ginseng in the SHR.

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The Inhibitory Effect of Shikonin on the Agonist-Induced Regulation of Vascular Contractility

  • Je, Hyun Dong;Kim, Hyeong-Dong;La, Hyen-Oh
    • Biomolecules & Therapeutics
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    • v.23 no.3
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    • pp.233-237
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    • 2015
  • Shikonin, a natural flavonoid found in the roots of Lithospermum erythrorhizon, has been shown to possess many biological functions. The present study was undertaken to investigate the influence of shikonin on vascular smooth muscle contractility and to determine the mechanism involved. Denuded aortic rings from male rats were used and isometric contractions were recorded and combined with molecular experiments. Shikonin significantly relaxed fluoride-, thromboxane $A_2$- or phorbol ester-induced vascular contraction suggesting as a possible anti-hypertensive on the agonist-induced vascular contraction regardless of endothelial nitric oxide synthesis. Furthermore, shikonin significantly inhibited fluoride-induced increases in pMYPT1 levels and phorbol ester-induced increases in pERK1/2 levels suggesting the mechanism involving the inhibition of Rho-kinase activity and the subsequent phosphorylation of MYPT1 and the inhibition of MEK activity and the subsequent phosphorylation of ERK1/2. This study provides evidence regarding the mechanism underlying the relaxation effect of shikonin on agonist-induced vascular contraction regardless of endothelial function.

LIPOPHILIC FRACTION FROM KOREAN RED GINSENG REGULATES THE PHOSPHORYLATION OF PLATELET PROTEIN(50KD) BY ELEVATING CYCLIC-GMP IN VIVO AND IN VITRO

  • Park H.J.;Rhee M.H.;Park K.M.;Nam K.Y.;Lee J.H.;Park K.H.
    • Proceedings of the Ginseng society Conference
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    • 1993.09a
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    • pp.94-101
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    • 1993
  • Lipophilic fraction(LF) from Panax ginseng C.A. Meyer inhibited the aggregation of human platelets induced by th rombin(0.1u/$m{\ell}$). LF and Molsidomine(vasodilator) induced the stimulation of cGMP - elevation and 50KD - Phosphorylation. and then the inhibition of 20KD - Phosphorylation in human platelets activated by thrombin. LF also inhibited the $Ca^{2-}-influx$ into platelets. When rat(SD : male) was fed with LF, the level of cGMP was increased in rat platelets stimulated by collagen and thrombin. On the other hand. verapamil, $Ca^{2-}-antagonist$ increased cAMP level ;n platelet stimulated by thrombin. but LF does not affected. However LF potently inhibited the thromboxane $A_2(TXA_2)$ production. The results suggest that the inhibitory effects of LF are mediated by regulation the phosphorylatior. of 50KD via cGMP-elevation and depend upon the decrease of $TXA_2$ level.

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Ginsenosides-mediated Vascular Relaxation and Its Molecular Mechanisms (진세노사이드의 혈관확장작용과 분자기전)

  • Kim, Nak-Doo
    • Journal of Ginseng Research
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    • v.32 no.2
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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.

Effects of Tenebrio molitor larvae oil on liver damage and blood clot formation in obesity

  • Bo Mi Park;Bong Joo Lee
    • Korean Journal of Veterinary Service
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    • v.46 no.2
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    • pp.107-113
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    • 2023
  • Tenebrio molitor, rich in protein, is used as an alternative protein source. Many studies have evaluated Tenebrio molitor larvae (TML) for anti-obesity effects, fatty liver relief, antithrombosis, and antioxidant effects. In this study, we prepared an experimental diet by adding Tenebrio molitor larvae oil (TMLO) to feed and administered it to adult male ICR mice for six weeks. The study assessed the weight gain of mice, prothrombin time (PT), activated partial thromboplastin time (aPTT), blood coagulation time, and the activities of coagulation factor VII and coagulation factor XII. The weight gain of mice was suppressed in the groups fed with TMLO, indicating a potential anti-obesity effect. The blood coagulation time was delayed in the TMLO-fed groups, as evidenced by amplified PT and aPTT values. Furthermore, the activities of coagulation factor VII and coagulation factor XII were diminished in the TMLO-treated groups, indicating a potential thrombosis relieving effect. The concentrations of thromboxane B2 and serotonin declined in the TMLO-fed groups, signifying potential blood circulation effects. Finally, blood triglyceride and LDL-cholesterol concentrations were reduced in the TMLO-fed groups. In summary, TMLO supplementation may have an inhibitory effect on liver damage and blood clot formation caused by obesity.

Antiplatelet effects of scoparone through up-regulation of cAMP and cGMP on U46619-induced human platelets

  • Lee, Dong-Ha
    • Journal of Applied Biological Chemistry
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    • v.62 no.4
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    • pp.425-431
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    • 2019
  • Platelet activation is essential for hemostatic process on blood vessel damage. However, excessive platelet activation can cause some cardiovascular diseases including atherosclerosis, thrombosis, and myocardial infarction. Scoparone is commonly encountered in the roots of genus Artemisia or Scopolia, and has been studied for its potential pharmacological properties including immunosuppression and vasorelaxation, but antiplatelet effects of scoparone have not been reported yet. We investigated the effect of scoparone on human platelet activation prompted by an analogue of thromboxane A2, U46619. As the results, scoparone dose-dependently increased cyclic adenosine monophosphate (cAMP) levels as well as cyclic guanosine monophosphate (cGMP) levels, both being aggregation-inhibiting molecules. In addition, scoparone strongly phosphorylated inositol 1, 4, 5-triphosphate receptor (IP3R) and vasodilator-stimulated phosphoprotein (VASP), substrates of cAMP dependent kinase and cGMP dependent kinase. Phosphorylation of IP3R by scoparone resulted in inhibition of Ca2+ mobilization in calcium channels in a dense tubular system, and phosphorylation of VASP by scoparone led to an inability of fibrinogen being able to bind to αIIb/β3. Finally, scoparone inhibited thrombin-induced fibrin clotting, thereby reducing thrombus formation. Therefore, we suggest that scoparone has a strong antiplatelet effect and is highly probable to prevent platelet-derived vascular disease.

The Effect of Luteolin on the Modulation of Vascular Contractility via ROCK and CPI-17 Inactivation

  • Hyuk-Jun, Yoon;Dae Hong, Kang;Fanxue, Jin;Joon Seok, Bang;Uy Dong, Sohn;Hyun Dong, Je
    • Biomolecules & Therapeutics
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    • v.31 no.2
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    • pp.193-199
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    • 2023
  • In this investigation, we made a study of the efficacy of luteolin (a flavonoid found in plants such as vegetables, herbs and fruits) on vascular contractibility and to elucidate the mechanism underlying the relaxation. Isometric contractions of denuded muscles were stored and combined with western blot analysis which was conducted to assess the phosphorylation of myosin phosphatase targeting subunit 1 (MYPT1) and phosphorylation-dependent inhibitory protein for myosin phosphatase (CPI-17) and to examine the effect of luteolin on the RhoA/ROCK/CPI-17 pathway. Luteolin significantly alleviated phorbol ester-, fluoride- and thromboxane mimetic-elicited contractions regardless of endothelial nitric oxide synthesis, implying its direct effect on smooth muscle. It also significantly alleviated the fluoride-elicited elevation in pCPI-17 and pMYPT1 levels and phorbol 12,13-dibutyrate-elicited increase in pERK1/2 level, suggesting depression of ROCK and PKC/MEK activity and ensuing phosphorylation of MYPT1, CPI-17 and ERK1/2. Taken together, these results suggest that luteolin-elicited relaxation includes myosin phosphatase reactivation and calcium desensitization, which seems to be arbitrated by CPI-17 dephosphorylation via ROCK/PKC inhibition.

The Changes of Body Fat Accumulation, Serum Lipids and Platelet Functions in Rat Fed the Diet Containing Different Common Oils in Korea: Sesame oil, Perilla oil, Rice Bran oil and Mixed oil (급원이 다른 식이 지방이 흰쥐의 지방대사와 혈소판 성상에 미치는 영향 -참깨유, 들깨유, 미강유 중심으로-)

  • 김숙희
    • Journal of Nutrition and Health
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    • v.26 no.5
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    • pp.513-523
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    • 1993
  • In this experiment, we investigated the hypolipidemic and antithrombotic effects of rats fed diets with different common oils in Korea for different feeding periods(4 weeks or 12 weeks), using Korean sesame oil, perilla oil, rice bran oil and mixed oil. W-3/w-6 ratio of each group was 0.001, 1.44, 0.03 and 0.112, respectively. P/S ratio of each group was 9.64, 10.49, 5.58 and 1.68, respectively. The result were as follows: 1) According to the age, body fat accumulation was increased. 2) Perilla oil(w-3 rich) decreased total lipid, triglyceride and total cholesterol, and increased HDL/total cholesterol ratio. 3) With regard to the compositono of platelet fatty acids, Perilla oil increased w-3/w-6 ratio of the platelet. Perilla oil lengthened bleeding time and decreased MDA(MalonDAdehyde) formation which determined in place of Thromboxane A2(TXA2) in platelet. This result can suggest that linoleic acid of perrilla oil seem to supress the conversion of linoleic acid to arachidonic acid(AA 20:4, w-6) and eicosapentaenoic acid(EPA, 20:5, w-3) trannnsformed from linolenic acid to suppress the conversion of arachidonic acid to TXA2. Since TXA2 is platelet-aggregating and vasoconstricting agent, the reduction of TXA2 tgeneration by platelet with increased linolenic acid intakes shows prologed bleeding time. In conclusion, w-3 rich perilla oil has strong hypolipidemic and antithrombotic effects by changing fatty acid profiles of the platelet.

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Antiplatelet Effect of Cudraxanthone L Isolated from Cudrania tricuspidata via Inhibition of Phosphoproteins

  • Shin, Jung-Hae;Rhee, Man Hee;Kwon, Hyuk-Woo
    • Natural Product Sciences
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    • v.26 no.4
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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.