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Updated: Aug 16, 2026

Turbidimetry on Human Washed Platelets: The Effect of the Pannexin1-inhibitor Brilliant Blue FCF on Collagen-induced Aggregation
Published on: April 6, 2017
14-deoxyandrographolide as a platelet activating factor antagonist in bovine neutrophils
Rafael A Burgos1, María A Hidalgo, Juan Monsalve
1Laboratory of Molecular Pharmacology, Institute of Pharmacology, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile. rburgos1@uach.cl
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 microM, 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 Ki of 7.8 x 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.

