Brazilin isolated from Caesalpinia sappan L. acts as a novel collagen receptor agonist in human platelets

Yi Chang, Steven Kuan Hua Huang, Wan Jung Lu, Chi Li Chung, Wei Lin Chen, Shun Hua Lu, Kuan Hung Lin, Joen Rong Sheu

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Background: Brazilin, isolated from the heartwood of Caesalpinia sappan L., has been shown to possess multiple pharmacological properties. Methods: In this study, platelet aggregation, flow cytometry, immunoblotting analysis, and electron spin resonance (ESR) spectrometry were used to investigate the effects of brazilin on platelet activation ex vivo. Moreover, fluorescein sodium-induced platelet thrombi of mesenteric microvessels was also used in in vivo study. Results: We demonstrated that relatively low concentrations of brazilin (1 to 10 muM) potentiated platelet aggregation induced by collagen (0.1 mug/ml) in washed human platelets. Higher concentrations of brazilin (20 to 50 muM) directly triggered platelet aggregation. Brazilin-mediated platelet aggregation was slightly inhibited by ATP (an antagonist of ADP). It was not inhibited by yohimbine (an antagonist of epinephrine), by SCH79797 (an antagonist of thrombin protease-activated receptor [PAR] 1), or by tcY-NH2 (an antagonist of PAR 4). Brazilin did not significantly affect FITC-triflavin binding to the integrin alphaIIbbeta3 in platelet suspensions. Pretreatment of the platelets with caffeic acid phenethyl ester (an antagonist of collagen receptors) or JAQ1 and Sam.Q4 monoclonal antibodies raised against collagen receptor glycoprotein VI and integrin alpha2beta1, respectively, abolished platelet aggregation stimulated by collagen or brazilin. The immunoblotting analysis showed that brazilin stimulated the phosphorylation of phospholipase C (PLC)gamma2 and Lyn, which were significantly attenuated in the presence of JAQ1 and Sam.Q4. In addition, brazilin did not significantly trigger hydroxyl radical formation in ESR analysis. An in vivo mouse study showed that brazilin treatment (2 and 4 mg/kg) significantly shortened the occlusion time for platelet plug formation in mesenteric venules. Conclusion: To the best of our knowledge, this study provides the first evidence that brazilin acts a novel collagen receptor agonist. Brazilin is a plant-based natural product, may offer therapeutic potential as intended anti-thrombotic agents for targeting of collagen receptors or to be used a useful tool for the study of detailed mechanisms in collagen receptors-mediated platelet activation.

Original languageEnglish
Pages (from-to)4
Number of pages1
JournalJournal of Biomedical Science
DOIs
Publication statusPublished - Jan 25 2013

Fingerprint

Caesalpinia
Collagen Receptors
Platelets
Blood Platelets
Platelet Aggregation
Agglomeration
Platelet Activation
Electron Spin Resonance Spectroscopy
Immunoblotting
Paramagnetic resonance
brazilin
Integrin alpha2beta1
Collagen
Chemical activation
Phospholipase C gamma
PAR-1 Receptor
Platelet Glycoprotein GPIIb-IIIa Complex
Phosphorylation
Yohimbine
Venules

ASJC Scopus subject areas

  • Pharmacology (medical)
  • Endocrinology, Diabetes and Metabolism
  • Biochemistry, medical
  • Cell Biology
  • Molecular Biology
  • Clinical Biochemistry

Cite this

Brazilin isolated from Caesalpinia sappan L. acts as a novel collagen receptor agonist in human platelets. / Chang, Yi; Huang, Steven Kuan Hua; Lu, Wan Jung; Chung, Chi Li; Chen, Wei Lin; Lu, Shun Hua; Lin, Kuan Hung; Sheu, Joen Rong.

In: Journal of Biomedical Science, 25.01.2013, p. 4.

Research output: Contribution to journalArticle

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abstract = "Background: Brazilin, isolated from the heartwood of Caesalpinia sappan L., has been shown to possess multiple pharmacological properties. Methods: In this study, platelet aggregation, flow cytometry, immunoblotting analysis, and electron spin resonance (ESR) spectrometry were used to investigate the effects of brazilin on platelet activation ex vivo. Moreover, fluorescein sodium-induced platelet thrombi of mesenteric microvessels was also used in in vivo study. Results: We demonstrated that relatively low concentrations of brazilin (1 to 10 muM) potentiated platelet aggregation induced by collagen (0.1 mug/ml) in washed human platelets. Higher concentrations of brazilin (20 to 50 muM) directly triggered platelet aggregation. Brazilin-mediated platelet aggregation was slightly inhibited by ATP (an antagonist of ADP). It was not inhibited by yohimbine (an antagonist of epinephrine), by SCH79797 (an antagonist of thrombin protease-activated receptor [PAR] 1), or by tcY-NH2 (an antagonist of PAR 4). Brazilin did not significantly affect FITC-triflavin binding to the integrin alphaIIbbeta3 in platelet suspensions. Pretreatment of the platelets with caffeic acid phenethyl ester (an antagonist of collagen receptors) or JAQ1 and Sam.Q4 monoclonal antibodies raised against collagen receptor glycoprotein VI and integrin alpha2beta1, respectively, abolished platelet aggregation stimulated by collagen or brazilin. The immunoblotting analysis showed that brazilin stimulated the phosphorylation of phospholipase C (PLC)gamma2 and Lyn, which were significantly attenuated in the presence of JAQ1 and Sam.Q4. In addition, brazilin did not significantly trigger hydroxyl radical formation in ESR analysis. An in vivo mouse study showed that brazilin treatment (2 and 4 mg/kg) significantly shortened the occlusion time for platelet plug formation in mesenteric venules. Conclusion: To the best of our knowledge, this study provides the first evidence that brazilin acts a novel collagen receptor agonist. Brazilin is a plant-based natural product, may offer therapeutic potential as intended anti-thrombotic agents for targeting of collagen receptors or to be used a useful tool for the study of detailed mechanisms in collagen receptors-mediated platelet activation.",
author = "Yi Chang and Huang, {Steven Kuan Hua} and Lu, {Wan Jung} and Chung, {Chi Li} and Chen, {Wei Lin} and Lu, {Shun Hua} and Lin, {Kuan Hung} and Sheu, {Joen Rong}",
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AU - Chang, Yi

AU - Huang, Steven Kuan Hua

AU - Lu, Wan Jung

AU - Chung, Chi Li

AU - Chen, Wei Lin

AU - Lu, Shun Hua

AU - Lin, Kuan Hung

AU - Sheu, Joen Rong

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N2 - Background: Brazilin, isolated from the heartwood of Caesalpinia sappan L., has been shown to possess multiple pharmacological properties. Methods: In this study, platelet aggregation, flow cytometry, immunoblotting analysis, and electron spin resonance (ESR) spectrometry were used to investigate the effects of brazilin on platelet activation ex vivo. Moreover, fluorescein sodium-induced platelet thrombi of mesenteric microvessels was also used in in vivo study. Results: We demonstrated that relatively low concentrations of brazilin (1 to 10 muM) potentiated platelet aggregation induced by collagen (0.1 mug/ml) in washed human platelets. Higher concentrations of brazilin (20 to 50 muM) directly triggered platelet aggregation. Brazilin-mediated platelet aggregation was slightly inhibited by ATP (an antagonist of ADP). It was not inhibited by yohimbine (an antagonist of epinephrine), by SCH79797 (an antagonist of thrombin protease-activated receptor [PAR] 1), or by tcY-NH2 (an antagonist of PAR 4). Brazilin did not significantly affect FITC-triflavin binding to the integrin alphaIIbbeta3 in platelet suspensions. Pretreatment of the platelets with caffeic acid phenethyl ester (an antagonist of collagen receptors) or JAQ1 and Sam.Q4 monoclonal antibodies raised against collagen receptor glycoprotein VI and integrin alpha2beta1, respectively, abolished platelet aggregation stimulated by collagen or brazilin. The immunoblotting analysis showed that brazilin stimulated the phosphorylation of phospholipase C (PLC)gamma2 and Lyn, which were significantly attenuated in the presence of JAQ1 and Sam.Q4. In addition, brazilin did not significantly trigger hydroxyl radical formation in ESR analysis. An in vivo mouse study showed that brazilin treatment (2 and 4 mg/kg) significantly shortened the occlusion time for platelet plug formation in mesenteric venules. Conclusion: To the best of our knowledge, this study provides the first evidence that brazilin acts a novel collagen receptor agonist. Brazilin is a plant-based natural product, may offer therapeutic potential as intended anti-thrombotic agents for targeting of collagen receptors or to be used a useful tool for the study of detailed mechanisms in collagen receptors-mediated platelet activation.

AB - Background: Brazilin, isolated from the heartwood of Caesalpinia sappan L., has been shown to possess multiple pharmacological properties. Methods: In this study, platelet aggregation, flow cytometry, immunoblotting analysis, and electron spin resonance (ESR) spectrometry were used to investigate the effects of brazilin on platelet activation ex vivo. Moreover, fluorescein sodium-induced platelet thrombi of mesenteric microvessels was also used in in vivo study. Results: We demonstrated that relatively low concentrations of brazilin (1 to 10 muM) potentiated platelet aggregation induced by collagen (0.1 mug/ml) in washed human platelets. Higher concentrations of brazilin (20 to 50 muM) directly triggered platelet aggregation. Brazilin-mediated platelet aggregation was slightly inhibited by ATP (an antagonist of ADP). It was not inhibited by yohimbine (an antagonist of epinephrine), by SCH79797 (an antagonist of thrombin protease-activated receptor [PAR] 1), or by tcY-NH2 (an antagonist of PAR 4). Brazilin did not significantly affect FITC-triflavin binding to the integrin alphaIIbbeta3 in platelet suspensions. Pretreatment of the platelets with caffeic acid phenethyl ester (an antagonist of collagen receptors) or JAQ1 and Sam.Q4 monoclonal antibodies raised against collagen receptor glycoprotein VI and integrin alpha2beta1, respectively, abolished platelet aggregation stimulated by collagen or brazilin. The immunoblotting analysis showed that brazilin stimulated the phosphorylation of phospholipase C (PLC)gamma2 and Lyn, which were significantly attenuated in the presence of JAQ1 and Sam.Q4. In addition, brazilin did not significantly trigger hydroxyl radical formation in ESR analysis. An in vivo mouse study showed that brazilin treatment (2 and 4 mg/kg) significantly shortened the occlusion time for platelet plug formation in mesenteric venules. Conclusion: To the best of our knowledge, this study provides the first evidence that brazilin acts a novel collagen receptor agonist. Brazilin is a plant-based natural product, may offer therapeutic potential as intended anti-thrombotic agents for targeting of collagen receptors or to be used a useful tool for the study of detailed mechanisms in collagen receptors-mediated platelet activation.

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