Effects of Plumbagin on Platelet Aggregation and Platelet-Neutrophil Interactions

Abstract

The effects of plumbagin were investigated on platelet aggregation in vitro and ex vivo, on the binding of thrombin-stimulated platelets to neutrophils, and platelet aggregation induced by intact neutrophils and N-formyl-methionyl-leucyl-phenylalanine (fMLP) or platelet activating factor (PAF) activated neutrophils, by use of the methods of Hamburger, McEver and Born, respectively. The results showed that plumbagin in vitro significantly inhibited adenosine diphosphate (ADP)-, arachidonic acid (AA)-, or platelet activating factor (PAF)-induced platelet aggregation, in a concentration-dependent manner. The medium inhibitory concentrations (IC₅₀) were 39.4, 82.7 and 38.1 μM, respectively. Intragastric plumbagin at 10 mg/kg markedly suppressed platelet aggregation induced by ADP, AA, or PAF. Plumbagin decreased the binding between thrombin-stimulated platelets and neutrophils with an IC₅₀ of 62.9 μM. Plumbagin significantly inhibited washed platelet aggregation stimulated by fMLP- or PAF-activated neutrophils. The IC₅₀ values were 54.3 and 47.6 μM, respectively. On the other hand, plumbagin and aspirin increased the inhibition of intact neutrophils on AA-induced platelet aggregation. It is suggested that plumbagin inhibited platelet aggregation in vitro and ex vivo, suppressed the binding of activated platelets to neutrophils, inhibited platelet aggregation induced by activated neutrophils, and increased inhibition of intact neutrophils on platelet reactivity.

Abbreviations

DMSO:dimethyl sulphoxide

fMLP:N-formyl-methionyl-leucyl-phenylalanine

ADP:adenosine diphosphate

AA:arachidonic acid

PAF:platelet activating factor

Key words

Plumbagin - platelet aggregation - platelet-neutrophil interactions

References

• 1 Bendnar M, Smith B, Pinto A, Mullane K. Neutrophil depletion suppresses ¹¹¹In-labelled platelet accumulation in infracted myocardium.  J Cardiovasc Pharmacol. 1985;  7 906-8
• 2 Lin Y, Wang Z. Platelet-neutrophil interaction in acute myocardial ischemia rate.  Basic Med Sci Clin. 1997;  17 376-80
• 3 Ott I, Neumann F J, Gawaz M, Schmitt M, Schomig A. Increased neutrophil-platelet adhesion in patients with unstable angina.  Circulation. 1996;  94 1239-46
• 4 Krishnaswamy M, Purushothaman K K. Plumbagin: a study of its anticancer, antibacterial and antifungal properties.  Ind J Exp Biol. 1980;  18 876-977
• 5 Sidhu G S, Sankaram A VB. New biplumbagin and 3-chloroplumbagin from Plumbago zeylanica .  Tetrahedron Lett. 1971;  26 2385-8
• 6 Sankaram A VB, Narayana V V, Marthandamurthi M. ¹³C NMR spectra of some natural occurring binaphthoquinones and related compounds.  Phytochemistry. 1986;  25 2867-71
• 7 Hamburger S A, McEver R P. GMP-140 mediates adhesion of stimulated platelets to neutrophils.  Blood. 1990;  75 550-4
• 8 Born G VR. Aggregation of blood platelets by adenosine diphosphate and its reversal.  Nature. 1962;  194 927-9
• 9 Hourani S MO, Hall D A. Receptors for ADP on human blood platelets.  TIPS. 1994;  15 103-8
• 10 Karen L KK, Alaina J A, Van H T, Colin C D, Basil D R. Gingerols and related analogues inhibit arachidonic acid-induced human platelet serotonin release and aggregation.  Thromb Res. 2001;  103 387-97
• 11 Snyder F. PAF and related acetylated lipids as potent biologically active cellular mediators.  Am J Physiol. 1990;  259 697-701
• 12 Stenberg P E, Mcever R P, Shuman M A, Jacques Y V, Bainton D F. A platelet alpha-granule membrane protein (GMP-140) is expressed on plasma membrane after activation.  J Cell Biol. 1985;  101 880-3
• 13 Robert F S, Heather M J, Robert G W, Stan H. Inhibition of ADP-induced P-selectin expression and platelet-leukocyte conjugate formation by clopidogrel and the P2Y₁₂ receptor antagonist AR-C69931MX but not aspirin.  Thrombosis and Haemostasis. 2002;  88 488-94
• 14 Marcus A J, Safier L B. Thromboregulation: multicellular modulation of platelet reactivity in haemostasis and thrombosis.  FASEB J. 1993;  7 516-22
• 15 Maschio A D, Evangelista V, Rajtar G, Chen Z M, Cerletti C, Gaetano G. Platelet activation by polymorphonuclear leukocytes exposed to chemotactic agents.  Am J Physiol. 1990;  258 H870-H9
• 16 Gaetano G, Evangelista V, Rajtar G, Del Maschio A, Cerletti C. Activated polymorphonuclear leukocytes stimulate platelet function. Thromb.  Res.. 1990;  (Suppl. XI) 25-32
• 17 Premakumari P, Rathinam K, Santhakumari G. Antifertility activity of plumbagin.  Ind J Med Res. 1977;  65 829-38