A sulphonoglycolipid from the fern Polypodium decumanum and its effect on the platelet activating-factor receptor in human neutrophils.
The South American fern Polypodium decumanum, traditional name calaguala, has documented clinical use in oral treatment of skin disorders, including psoriasis. The inflammatory mediator platelet-activating factor (PAF), has been implicated in the pathogenesis of psoriasis. A constituent of a calaguala extract has been shown to have inhibitory activity in a PAF-induced exocytosis model in human neutrophils. The compound was identified as the sulphoquinovosyl diacylglycerol 1,2-di-O-palmitoyl-3-O-(6-sulpho-alpha-D-quinovopyranosyl)-glycero l by spectroscopic means. When subsequently studied in an in-vitro model for [3H]PAF binding in neutrophils from man the compound caused dose-dependent displacement of [3H]PAF from its receptor with an IC50 value of 2 microM. It is suggested that the compound acts through PAF receptor antagonism in intact human neutrophils.
Vasänge
M
M
Department of Pharmacy, Uppsala University, Sweden.
Rolfsen
W
W
Bohlin
L
L
D005089:Exocytosis / Q000187:drug effects; D008401:Gas Chromatography-Mass Spectrometry; D006017:Glycolipids / Q000302:isolation & purification / Q000494:pharmacology*; D006801:Humans; D019272:Leukocyte Elastase / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D009504:Neutrophils / Q000187:drug effects* / Q000201:enzymology / Q000648:ultrastructure*; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D010946:Plants, Medicinal / Q000737:chemistry; D010972:Platelet Activating Factor / Q000378:metabolism / Q000494:pharmacology; D010980:Platelet Membrane Glycoproteins / Q000187:drug effects*; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; D014316:Tritium
D006017:Glycolipids; D010936:Plant Extracts; D010972:Platelet Activating Factor; D010980:Platelet Membrane Glycoproteins; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; C039351:platelet activating factor receptor; D014316:Tritium; D019272:Leukocyte Elastase