p38 Mitogen-Activated Protein Kinase의 억제를 통한 진세노사이드 Rg3의 Thromboxane A₂ 억제 효과

권혁우(Hyuk-Woo Kwon) 한국식품영양과학회 2018 한국식품영양과학회지 Vol.47 No.9

G-Rg3는 인삼의 성분으로서 많은 효과가 밝혀졌지만, 혈소판에서의 억제 기작에 대한 연구는 미흡하다. 본 연구에서는 G-Rg3가 혈소판에서 합성되어 분비되는 TXA₂의 생산에 관여한다고 알려진 효소인 COX-1, TXAS와 신호전달 분자인 p38 MAPK, cPLA₂의 인산화를 어떻게 조절하며 혈소판응집을 억제시키는지 규명하고자 하였다. 그 결과 G-Rg3는 thrombin이 유도한 혈소판 응집을 강력하게 억제하였고, p38 MAPK, cPLA₂의 인산화와 COX-1, TXAS의 활성을 감소시키며 arachidonic acid 분비와 TXA₂의 합성을 농도의존적으로 억제하였다. 또한 G-Rg3는 thrombin이 촉진시킨 p38의 인산화를 억제함으로써 과립방출의 지표인 ATP와 serotonin의 방출을 억제하였다. 따라서 G-Rg3는 인체혈소판에서 TXA₂의 생성을 억제함으로써 혈소판 응집억제를 나타내는 치료 및 예방약물로서 유용한 가치가 있다고 여겨진다. Thromboxane A₂ plays a central role in hemostasis and thrombus formation, which stimulates other platelets as an agonist leading intracellular signaling cascades. In this study, we tried to explain the inhibitory mechanism of 20(S)-ginsenoside Rg3 (G-Rg3) on thromboxane A₂ production by assaying the activities of TXA₂ production-associated microsomal enzymes and associated signaling molecules. Thrombin-stimulated human platelet aggregation was dose-dependently decreased by G-Rg3 and attenuated thromboxane A₂ production via down regulation of microsomal cyclooxygenase-1 and thromboxane A₂ synthase activities. In addition, arachidonic acid release, which is a precursor of TXA₂ was decreased by G-Rg3 through dephosphorylation of cytosolic phospholipase A₂ and p38 mitogen-activated protein kinase. Overall, the results revealed the specific signaling pathway of TXA₂ production via G-Rg3. Therefore, G-Rg3 is a beneficial novel compound inhibiting TXA₂ production, which may prevent platelet aggregation-mediated thrombotic disease.

본태성 고혈압 및 동맥경화성 질환에서의 Prostacyclin 과 Thromboxane A₂ 혈장농도에 대한 고찰

지영구(Young Koo Jee),한형수(Hyung Soo Han),정문성(Moon Sung Jung),이봉휘(Bong Hwi Lee),김관우(Kwan Woo Kim),문언수(Un Soo Moon),한창순(Chang Soon Han),이홍순(Hong Soon Lee),이학중(Hak Joong Lee) 대한내과학회 1990 대한내과학회지 Vol.39 No.4

N/A The concentrations of the metabolites of prostacyclin and thromboxane A₂ (6-keto-PGF1α and 11-dehydro-TxB2) were measured in essential hypertension and artherosclerotic disease, and the concentrations of metabolites were compared after administration of 100 mg/日, 300 mg/日 and 900 mg/ 日of aspirin. The findings were as follows: 1) The concentrations of 6-keto-PGF1α and 11-dehydro-TxB₂ were significantly higher in the essential hypertension group and artherosclerotic disease group than in the control group (p<0.001). 2) The concentrations of 6-keto-PGF1α and 11-dehydro-TxB₂ were higher in the high cholesterol group (p<0.01, p<0.05, respectively). 3) With aspirin administration, the concenatrations of 6-keto-PGF1α and 11-dehydro-TxB₂ were significantly reduced (about 70% was reduced seven days after administration of aspirin). 4) There were no significant differences in reducing the concentrations of 6-keto-PGF1α and 11-dehydro-TxB₂ between three groups of different dosages of aspirin, 100 mg/日, 300 mg/日, and 900 mg/日 of aspirin. These findings suggest that thromboxane A₂ may contribute to the development or progression of hypertension and artherosclerotic disease. 100 mg/ 日 of aspirin may be used as effective as 300 mg/日 or 900 mg/日 of aspirin in preventing thrombotic events.

Thromboxane A2 Synthetase Inhibitor Plus Low Dose Aspirin : Can It Be a Salvage Treatment in Acute Stroke Beyond Thrombolytic Time Window

An, Gyu-Hwan,Sim, Sook-Young,Jwa, Cheol-Su,Kim, Gang-Hyeon,Lee, Jong-Yun,Kang, Jae-Kyu The Korean Neurosurgical Society 2011 Journal of Korean neurosurgical society Vol.50 No.1

Objective : There is no proven regimen to reduce the severity of stroke in patients with acute cerebral infarction presenting beyond the thrombolytic time window. Ozagrel sodium, a selective thromboxane A2 synthetase inhibitor, has been known to suppress the development of infarction. The antiplatelet effect is improved when aspirin is used together with a thromboxane synthetase inhibitor. Methods : Patients with non-cardiogenic acute ischemic stroke who were not eligible for thrombolysis were randomly assigned to two groups; one group received ozagrel sodium plus 100 mg of aspirin (group 1, n=43) and the other 100 mg of aspirin alone (group 2, n=43). Demographic data, cardiovascular risk factors, initial stroke severity [National Institute of Health Stroke Scale (NIHSS) and motor strength scale] and stroke subtypes were analyzed in each group. Clinical outcomes were analyzed by NIHSS and motor strength scale at 14 days after the onset of stroke. Results : There were no significant differences in the mean age, gender proportion, the prevalence of cardiovascular risk factors, stroke subtypes, and baseline neurological severity between the two groups. However, the clinical outcome for group 1 was much better at 14 days after the onset of stroke compared to group 2 (NIHSS score, p=0.007, Motor strength scale score, p<0.001). There was one case of hemorrhagic transformation in group 1, but there was no statistically significant difference in bleeding tendency between two groups. Conclusion : In this preliminary study, thromboxane A2 synthetase inhibitor plus a low dose of aspirin seems to be safe and has a favorable outcome compared to aspirin alone in patients with acute ischemic stroke who presented beyond the thrombolytic time window.

흰쥐에서의 CYCLOSPORIN A-유발 간독성에 대한 THROMBOXANE A₂-수용체 길항제인 KT2-962의 효과

신인철,강주섭,서대규,김정희 한양대학교 의과대학 1993 한양의대 학술지 Vol.13 No.1

Cyclosporine (CsA) is now widely used as immunosuppressive agents which has the unique capacity to prolong graft survival by a selective inhibitory effect on antigen-reactive T-lymphocytes. But, its renal toxicity is a major limiting factor for clinical use of CsA and is partially related to renal hemodynamic alteration. It has been suggested that thromboxane (TX) A₂would be one of the critical mediators of altered renal meondynamics. Therefore, various factors and effects can be participated in the toxic effect of CsA on liver function. In this study, the effect of KT2-962 (KT), an azulene derivative of recently synthesized selective TXA₂receptor antagonist on preventing acute hephtoxicity in CsA -treated rats was examined and blood glucose level. COT and CPT activity, and body weight were measured. Ultrastructural changes of the hephtocyte were evaluated by electron microscopy. Male Wistar rats were administered of CsA (25mg/kg, i.p) or KT2-962(30mg/kg,p.o) with CsA (25mg/kg, i.p) once a day for 20 consecutive days. The pretreatment of extra KT2 for 3 days was done before coadministration of CsA+KT2. The results (values are means±SE) obtained can be summarized as follows: 1) Body Weight (gm): Body weight was progressively increased and gained about 66.06±3.1(251.1 vs 318.7) on 3rd week of treatment in the control group. In contrast, there was weight loss of 37.1±2.8 (259.5 vs 220.9) in the CsA group. KT2 cotreatment with CsA inhibited weight loss by CsA and gained 40.2±1.9 (250.2 vs 290.4). 2) Blood glucose concentration (mg/dl): Blood glucose level was significantly increased to 2.3 times compared with control group (92.5 vs 210.0) in the CsA group. But, in the KT2+CsA group the blood glucose level within normal range preserved. 3) Serum GPT activity(U/L) : Serum GPT activity was significantly increased to 4.1 times compared with control group (24.4 vs 100.3) in the CsA group. But, in the KT2+CsA group, it was slighty increased to 1.9 times as control group and corresponded to below half of CsA group. 4) Serum GOT activity (U/L): Serum GOT activity was markedly increased to 4.6 times compared with control group (46.5 vs 215.7) in the CsA group. But, in the KT2+CsA group, it was slightly increased to 1.4 times compared with control group and correspond to below 70% of CsA group. 5) In the electron microscopic finding of a hepatocyte in CsA group. Nucleus is deformed. Mitochondria are swollen and cisternae of the rough endoplasmicis reticulum are dilated and sacculated. Autophagic vacuoles are seen, Golgi complex is slightly hypertrophied and amount of glycogen particles is reduced. But in the KT2+CsA group. Nucleus is round and rough endoplasmic reticula are evenly distributed and consist of paralelled cidternae with ribosomegranules. Mitochondria and Golgi complex are seen. Glycogen particles are distributed in large number. Consequently, it is suggested that endogenous TXA₂may be related with CsAhepatotoxicity and cotreatment of selective TXA₂receptor antagonist, TXA₂-962 can suppress CsA-induced hepatotoxicity in rats.

트롬복산 A₂와 트롬복산 A₂ 수용체 길항제의 활성형태

이종달,도성탁 영남대학교 약품개발연구소 1998 영남대학교 약품개발연구소 연구업적집 Vol.8 No.-

Conformational analyses on thromboxane A₂ (TxA₂) and thromboxane A₂ receptor antagonists (TxRA) were carried out by molecular mechanics method. Based on the assumption that active conformer is the nonintrahydrogen bonding and more stable former of TxA₂ and TxRA the molecular structural requirements for potent TxA₂ receptor antagonists are like below: 1) The distance is 5.0~5.6Å between C atom of carboxyl group and S atom of sulfonyl group or C atom which is bonded to hydroxyl group in the active conformers. 2) The putative active conformers of TxA₂ and TxRAs are hairpin-like forms.

트롬복산 A2와 트롬복산 A2 수용체 길항제의 활성형태

이종달(Jong Dal Rhee),도성탁(Seong Tak Doh) 대한약학회 1997 약학회지 Vol.41 No.6

Conformational analyses on thromboxane A2 (TxA2) and thromboxane A2 receptor antagonists (TxRA) were carried out by molecular mechanics method. Based on the assumption that active conformer is the nonintrahydrogen bonding and more stable former of TxA2 and TxRA, the molecular structural requirements for potent TxA2 receptor antagonists are like below: 1) The distance is 5.0-5.6 A.U. between C atom of carboxyl group and S atom of sulfonyl group or C atom which is bonded to hydroxyl group in the active conformers. 2) The putative active conformers of TxA2 and TxRAs are hairpin-like forms.

Inhibitory effects of thromboxane A2 generation by ginsenoside Ro due to attenuation of cytosolic phospholipase A2 phosphorylation and arachidonic acid release

신정해,권혁우,이만휘,박화진 고려인삼학회 2019 Journal of Ginseng Research Vol.43 No.2

Background: Thromboxane A2 (TXA2) induces platelet aggregation and promotes thrombus formation. Although ginsenoside Ro (G-Ro) from Panax ginseng is known to exhibit a Ca2þ-antagonistic antiplatelet effect, whether it inhibits Ca2þ-dependent cytosolic phospholipase A2 (cPLA2a) activity to prevent the release of arachidonic acid (AA), a TXA2 precursor, is unknown. In this study, we attempted to identify the mechanism underlying G-Ro-mediated TXA2 inhibition. Methods: We investigated whether G-Ro attenuates TXA2 production and its associated molecules, such as cyclooxygenase-1 (COX-1), TXA2 synthase (TXAS), cPLA2a, mitogen-activated protein kinases, and AA. To assay COX-1 and TXAS, we used microsomal fraction of platelets. Results: G-Ro reduced TXA2 production by inhibiting AA release. It acted by decreasing the phosphorylation of cPLA2a, 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 TXA2 production, which may counteract TXA2-associated thrombosis.

Inhibitory effects of thromboxane A₂ generation by ginsenoside Ro due to attenuation of cytosolic phospholipase A₂ phosphorylation and arachidonic acid release

Jung-Hae Shin,Hyuk-Woo Kwon,Man Hee Rhee,Hwa-Jin Park 고려인삼학회 2019 Journal of Ginseng Research Vol.43 No.2

Background: Thromboxane A₂ (TXA₂) induces platelet aggregation and promotes thrombus formation. Although ginsenoside Ro (G-Ro) from Panax ginseng is known to exhibit a Ca<SUP>2+</SUP>-antagonistic antiplatelet effect, whether it inhibits Ca<SUP>2+</SUP>-dependent cytosolic phospholipase A₂ (cPLA2a) activity to prevent the release of arachidonic acid (AA), a TXA₂ precursor, is unknown. In this study, we attempted to identify the mechanism underlying G-Ro-mediated TXA₂ inhibition. Methods: We investigated whether G-Ro attenuates TXA₂ production and its associated molecules, such as cyclooxygenase-1 (COX-1), TXA₂ synthase (TXAS), cPLA2a, mitogen-activated protein kinases, and AA. To assay COX-1 and TXAS, we used microsomal fraction of platelets. Results: G-Ro reduced TXA₂ production by inhibiting AA release. It acted by decreasing the phosphorylation of cPLA2a, 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 TXA₂ production, which may counteract TXA₂-associated thrombosis.

Influence of Thromboxane A2 on the Regulation of Adenosine Triphosphate-Sensitive Potassium Channels in Mouse Ventricular Myocytes

In Seok Jeong,조화진,Jeong Gwan Cho,Sang Hyung Kim,Kook Joo Na,Jong-Keun Kim 대한심장학회 2016 Korean Circulation Journal Vol.46 No.4

Background and Objectives: Adenosine triphosphate (ATP)-sensitive potassium (KATP) channels play an important role in myocardial protection. We examined the effects of thromboxane A2 on the regulation of KATP channel activity in single ventricular myocytes. Materials and Methods: Single ventricular myocytes were isolated from the hearts of adult Institute of Cancer Research (ICR) mice by enzymatic digestion. Single channel activity was recorded by excised inside-out and cell-attached patch clamp configurations at -60 mV holding potential during the perfusion of an ATP-free K-5 solution. Results: In the excised inside-out patches, the thromboxane A2 analog, U46619, decreased the KATP channel activity in a dose-dependent manner; however, the thromboxane A2 receptor antagonist, SQ29548, did not significantly attenuate the inhibitory effect of U46619. In the cell-attached patches, U46619 inhibited dinitrophenol (DNP)-induced KATP channel activity in a dose-dependent manner, and SQ29548 attenuated the inhibitory effects of U46619 on DNP-induced KATP channel activity. Conclusion: Thromboxane A2 may inhibit KATP channel activity, and may have a harmful effect on ischemic myocardium.

Panaxadiol from Panax ginseng C.A. Meyer Inhibits Synthesis of Thromboxane $A_2$ in Platelet Aggregation Induced by Thrombin

Park, Hwa-Jin,Rhee, Man-Hee,Park, Kyeong-Mee,Nam, Ki-Yeul,Park, Ki-Hyun The Korean Society of Ginseng 1993 Journal of Ginseng Research Vol.17 No.2

Panaxadiol (PD) from Korean red ginseng C.A. Meyer did not control the concentration of cytosolic free $Ca^{2+}$ influxes by thrombin (5 $\mu$/ml). However, PD strongly inhibited the synthesis of thromboxane. $A_2$ (TX$A_2$) in the aggregation of human platelets induced by thrombin (5 $\mu$/ml). These rexults suggest that PD blocks the any Pathway transforming to TX$A_2$ from arachidonic acid (AA) which release out of plasma membrane phospholipids by $Ca^{2+}$-dependent phospholipase C or phospholipase $A_2$. It may be also concluded that PD has the antiplatelet function by inhibiting the synthesis of TX$A_2$, which known to be the potent stimulator of the aggregation of human platelet.