14-Deoxyandrographolide as a Platelet Activating Factor Antagonist in Bovine Neutrophils

Abstract

14-Deoxyandrographolide (14-DAP) is a labdane diterpene isolated from Andrographis paniculata with previously reported calcium channel blocking activity. Its potential platelet activating factor (PAF) antagonistic activity in bovine neutrophils was assessed. 14-DAP, in concentrations between 10 - 100 μM, reduced the extracellular acidification rate and the intracellular alkalinization in a dose-dependent manner. In addition, 14-DAP reduced PAF-induced calcium flux in the presence of extracellular calcium, and tyrosine phosphorylation of a 44 kDa protein corresponding to the MAPK^ERK1. However, 14-DAP reduced the ³H-PAF binding with a K_i of 7.8 × 10 ^{- 9} M, and a Hill slope of 0.63, suggesting that there is more than one binding site for 14-DAP. We concluded that 14-DAP is an effective antagonist of PAF-mediated processes in bovine neutrophils, probably by virtue of its calcium channel blocking property.

Key words

PAF - calcium - pH - neutrophils - 14-deoxyandrographolide - MAPK - Andrographis paniculata - Acanthaceae

References

• 1 Prescott S M, Zimmerman G A, Stafforini D M, McIntyre T M. Platelet-activating factor and related lipid mediators.  Annu Rev Biochem. 2000;  69 419-45
• 2 Burgos R A, Hidalgo M A, Matthei S M, Hermosilla R, Folch H, Hancke J L. Determination of specific receptor sites for platelet activating factor in bovine neutrophils.  Am J Vet Res. 2004;  65 628-36
• 3 Swain S D, Bunger P L, Sipes K M, Nelson L K, Jutila K L, Boylan S M, Quinn M T. Platelet-activating factor induces a concentration-dependent spectrum of functional responses in bovine neutrophils.  J Leukocyte Biol. 1998;  64 817-27
• 4 Hidalgo M A, Ojeda F, Eyre P, LaBranche T P, Smith C, Hancke J L, Burgos R A. Platelet-activating factor increases pH(i) in bovine neutrophils through the PI3K-ERK1/2 pathway.  Br J Pharmacol. 2004;  141 311-21
• 5 McClenahan D J, Evanson O A, Weiss D J. In vitro evaluation of the role of platelet-activating factor and interleukin-8 in Mannheimia haemolytica-induced bovine pulmonary endothelial cell injury.  Am J Vet Res. 2002;  63 394-401
• 6 Montrucchio G, Alloatti G, Camussi G. Role of platelet-activating factor in cardiovascular pathophysiology.  Physiol Rev. 2000;  80 1669-99
• 7 Negro Alvarez J M, Miralles Lopez J C, Ortiz Martinez J L, Abellan Aleman A, Rubio del Barrio R. Platelet-activating factor antagonists.  Allergol Immunopathol (Madr). 1997;  25 249-58
• 8 Han B H, Yang H O, Kang Y H, Suh D Y, Go H J, Song W J, Kim Y C, Park M K. In vitro platelet-activating factor receptor binding inhibitory activity of pinusolide derivatives: a structure-activity study.  J Med Chem. 1998;  41 2626-30
• 9 Amroyan E, Gabrielian E, Panossian A, Wikman G, Wagner H. Inhibitory effect of andrographolide from Andrographis paniculata on PAF-induced platelet aggregation.  Phytomedicine. 1999;  6 27-31
• 10 Burgos R A, Loyola M, Hidalgo M A, Labranche T P, Hancke J L. Effect of 14-deoxyandrographolide on calcium-mediated rat uterine smooth muscle contractility.  Phytother Res. 2003;  17 1011-5
• 11 Matsuda T, Kuroyanagi M, Sugiyama S, Umehara K, Ueno A, Nishi K. Cell differentiation-inducing diterpenes from Andrographis paniculata Nees.  Chem Pharm Bull (Tokyo). 1994;  42 1216-25
• 12 Pick E. Microassays for superoxide and hydrogen peroxide production and nitroblue tetrazolium reduction using and enzyme immunoassays microplate reader.  Methods Enzymol. 1986;  132 407-421
• 13 Trevani A S, Andonegui G, Giordano M, Lopez D H, Gamberale R, Minucci F, Geffner J R. Extracellular acidification induces human neutrophil activation.  J Immunol. 1999;  162 4849-57
• 14 Osaki M, Sumimoto H, Takeshige K, Cragoe E J, Jr., Hori Y, Minakami S. Na⁺/H⁺ exchange modulates the production of leukotriene B4 by human neutrophils.  Biochem J. 1989;  257 751-8
• 15 Simchowitz L. Intracellular pH modulates the generation of superoxide radicals by human neutrophils.  J Clin Invest. 1985;  76 1079-89
• 16 Filep J G, Foldes-Filep E. Inhibition by calcium channel blockers of the binding of platelet-activating factor to human neutrophil granulocytes.  Eur J Pharmacol. 1990;  190 67-73
• 17 Elzi D J, Hiester A A, Silliman C C. Receptor-mediated calcium entry is required for maximal effects of platelet activating factor primed responses in human neutrophils.  Biochem Biophys Res Commun. 1997;  240 763-5
• 18 Hauser C J, Fekete Z, Adams J M, Garced M, Livingston D H, Deitch E A. PAF-mediated Ca²⁺ influx in human neutrophils occurs via store-operated mechanisms.  J Leukocyte Biol. 2001;  69 63-8
• 19 Boucek M M, Snyderman R. Calcium influx requirement for human neutrophil chemotaxis: inhibition by lanthanum chloride.  Science. 1976;  193 905-7
• 20 Granfeldt D, Samuelsson M, Karlsson A. Capacitative Ca²⁺ influx and activation of the neutrophil respiratory burst. Different regulation of plasma membrane- and granule-localized NADPH-oxidase.  J Leukocyte Biol. 2002;  71 611-7