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Molecules 2010 Nov 3;15(11):7840-8. Epub 2010 Nov 3.

Faculty of Pharmacy, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, Kuala Lumpur 50300, Malaysia.

Phylligenine, together with quebrachitol, stigmasterol and two aporphine alkaloids--oxoputerine and liriodenine--were isolated from the twigs of Mitrephora vulpina C.E.C. Read More

Molecules 2010 Jul 29;15(8):5124-38. Epub 2010 Jul 29.

Faculty of Pharmacy, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, Kuala Lumpur, Malaysia.

Nine essential oils, hydrodistilled from different parts of five Goniothalamus species (G. velutinus Airy-Shaw, G. woodii Merr. Read More

Biol Pharm Bull 2007 Jun;30(6):1150-2

Forest Research Institute Malaysia, Selangor Darul Ehsan.

The leaf, stem and root extracts of Chromolaena odorata were evaluated for their effect on platelet-activating factor (PAF) receptor binding on rabbit platelets using 3H-PAF as a ligand. The leaf extract demonstrated high PAF receptor binding inhibitory activity of 79.2+/-2. Read More

Yao Xue Xue Bao 2006 Jan;41(1):36-40

Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China.

Aim: To investigate the effect of ginkgolide B on the proliferation of VSMC and the secretion of chemokines by U937 cells stimulated by oxLDL or PAF. In addition, to analyze whether the effect of oxLDL is mediated through PAF receptor.

Methods: Using 3H-Tdr incorporation assay, the proliferation of VSMC was measured. Read More

Phytother Res 2004 Dec;18(12):1005-7

Department of Pharmacy, Faculty of Allied Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia.

Ten compounds isolated from Alpinia mutica Roxb., Curcuma xanthorrhiza Roxb. and Kaempferia rotunda Linn. Read More

Phytomedicine 2005 Jan;12(1-2):88-92

Department of Pharmacy, Faculty of Allied Health Sciences, University Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, Kuala Lumpur 50300, Malaysia.

Forty-nine methanol extracts of 37 species of Malaysian medicinal plants were investigated for their inhibitory effects on platelet-activating factor (PAF) binding to rabbit platelets, using 3H-PAF as a ligand. Among them, the extracts of six Zingiberaceae species (Alpinia galanga Swartz., Boesenbergia pandurata Roxb. Read More

Zhongguo Zhong Yao Za Zhi 2004 Aug;29(8):789-91

Department of Pharmacology, Beijing Institute of Heart, Lung and Blood Vessel Diseases-Anzhen Hospital, Beijing 100029, China.

Objective: To observe the platelet activating factor (PAF) antagonistic effect of kaempferol.

Method: The specific binding of [3H] PAF to rabbit platelet receptor was investigatedwith radio ligand binding assay (RLBA). Platelet adhesion induced by PAF was measured with spectrophotometry. Read More

Yao Xue Xue Bao 2003 Nov;38(11):831-3

Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing Anzhen Hospital, Beijing 100029, China.

Aim: To study the antagonistic effect of myricetin on platelet activing factor (PAF).

Methods: The specific binding of [3H] PAF to rabbit platelet receptor was investigated using radio ligand binding assay (RLBA). Platelet adhesion induced by PAF was measured with spectrophotometry. Read More

Yao Xue Xue Bao 2002 Sep;37(9):696-9

Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing 100029, China.

Aim: To observe the antagonistic effect of hydroxysafflor yellow A (HSYA) on the platelet activating factor (PAF).

Methods: Washed rabbit platelet (WRP) aggregation and rabbit polymorphonuclear leukocytes (PMNs) aggregation induced by PAF were observed by turbidimetric assay in vitro. The PAF receptor antagonistic effect of HSYA was investigated by radio ligand binding assay (RLBA). Read More

Planta Med 2002 Dec;68(12):1133-4

Department of Pharmacy, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia.

Rubraxanthone and isocowanol isolated from Garcinia parvifolia Miq. were investigated for their inhibitory effects on platelet-activating factor (PAF) binding to rabbit platelets using 3H-PAF as a ligand. Rubraxanthone showed a strong inhibition with IC 50 value of 18. Read More

Planta Med 2001 Jul;67(5):466-7

receptor binding, with IC50 values of 52.4, 38.6, and 29.8 microM, respectively. The flexibility of the biphenyl system of the aporphine and the presence of methoxy groups at C-9 and C-10 were all preferable in binding to the receptor.

Six aporphine and one phenanthrenoid alkaloids isolated from Aromadendron elegans Blume were investigated for their inhibitory effect on platelet-activating factor (PAF) binding to rabbit platelets using 3H-PAF as a ligand. Of the compounds tested, (-)-N-acetylanonaine, 1-(N-acetyl-N-methylamino)ethyl-3,4,6-trimethoxy-7-hydroxy-phenanthrene, and predicentrine showed strong inhibition of Read More

Planta Med 1998 Feb;64(1):72-4

The water extract of Biota orientalis showed a potent inhibitory effect on platelet activating factor (PAF) binding to rabbit platelets using [3H]PAF as a ligand in our previous screening studies for Korean medicinal antagonists by the activity-guided purification studies. Another active compound, compound 1 (IC50 = 2.3 x 10(-5) M, 7. Read More

J Immunol 1994 Jan;152(2):793-800

Department of Medicine, Beth Israel Hospital, Boston, MA 02215.

A human neutrophil platelet-activating factor (PAF) receptor expressed in transfected cells was utilized to study receptor-dependent interactions with the ligand. This receptor displays ligand-binding properties comparable with those observed with naturally occurring receptor-positive cells when binding experiments are performed using COS-7 cells at 4 degrees C. The ligand-receptor interaction is markedly temperature dependent, with approximately 10-fold more [3H]PAF specifically associated with the cells at 37 degrees C than at 4 degrees C. Read More

Lipids 1991 Dec;26(12):1148-53

Merck Sharp & Dohme Research Laboratories, Department of Biochemical Regulation, Rahway, New Jersey 07065-0900.

L-659,989 is a potent, specific and competitive platelet-activating factor (PAF) receptor antagonist. The 2,5-tritium labeled L-659,989, similar to [3H]PAF, specifically binds to rabbit platelet membranes with an equilibrium dissociation constant (KD) of 1.60 (+/- 0. Read More

Biochem J 1991 Sep;278 ( Pt 2):405-10

Department of Medicine, University of British Columbia, Vancouver, Canada.

Binding of platelet-activating factor (PAF) to a specific high-affinity membrane receptor has been demonstrated in numerous cell types, but very little is known about the molecular nature of this receptor. The receptor from rabbit platelets was solubilized using CHAPS, digitonin, octyl glucoside, Nonidet P-40 or sodium cholate, either with pre-bound [3H]PAF or in the absence of ligand. We have been able to demonstrate for the first time that the receptor solubilized with CHAPS, in the absence of ligand, could retain its binding activity. Read More

Biochem Pharmacol 1991 Feb;41(4):629-30

Istituto di Farmacologia, Università di Ferrara, Italy.

Our results indicate that the binding of [3H]PAF to a single class of high affinity sites on human platelets is endothermic and largely entropy-driven. The increase in entropy can be attributed to the disorganization of water molecules bound to both receptor and ligand during the binding process. Read More

Proc Soc Exp Biol Med 1990 Nov;195(2):247-54

Department of Molecular and Cell Biology, G. D. Searle & Co., Skokie, Illinois 60077.

The characteristics of receptors for platelet-activating factor (PAF) on rabbit neutrophils are investigated in this report. The presence of PAF-specific binding to rabbit neutrophils was confirmed using radiolabeled ligand binding assays and a rabbit peritoneal neutrophil membrane preparation. Binding of PAF to the neutrophil membranes was reversible and reached equilibrium within 30 min. Read More

J Biol Chem 1990 Oct;265(29):17576-83

Department of Biochemistry, University of Texas Health Science Center, San Antonio 78284-7760.

Treatment of cultured Kupffer cells with the beta-adrenergic agonist isoproterenol (10 microM) for a short period of time (30 min) attenuated the subsequent platelet-activating factor (PAF)-induced arachidonic acid release and cyclooxygenase-derived eicosanoid (e.g. thromboxane B2 and prostaglandin E2) production. Read More

Biol Reprod 1990 Sep;43(3):368-77

Department of Obstetrics and Gynecology, University of Texas Health Science Center, San Antonio 78284-7836.

High affinity receptors have been demonstrated for the potent phospholipid autacoid, platelet-activating factor (PAF C18:0; 1-O-alkyl-2-acetyl-sn-glycero-3-phosphorylcholine) in a variety of tissues, including the endometrium. Because of the relative instability of PAF and our previous demonstration that lyso-PAF (1-O-alkyl-2-lyso-sn-glycero-3-phosphorylcholine), the major metabolite of PAF, displaced [3H]PAF from endometrial PAF receptor sites, we have examined the ability of bovine serum albumin (BSA) to prevent degradation of PAF and have characterized PAF and lyso-PAF binding sites in purified rabbit endometrial membranes isolated on Day 6 of pregnancy. In buffer containing the phospholipase A2 inhibitors, quinacrine (10 microM) and dibromoacetophenone (2 microM), and 0. Read More

J Pharmacol Exp Ther 1990 Mar;252(3):1221-7

Rhone-Poulenc Sante, Centre de Recherches de Vitry, Vitry-Sur-Seine Cedex, France.

In human platelet membranes, [3H]platelet-activating factor(PAF)-C18 binding sites exhibited high affinity (Kd 0.074 +/- 0.005 nM, n = 28 healthy volunteers), saturability, elevated stereoselectivity, marked pharmacological specificity and small intersubject variability. Read More

Biol Reprod 1989 Oct;41(4):587-603

Department of Obstetrics and Gynecology, University of Texas Health Science Center, San Antonio 78284-7836.

One of the earliest signs of endometrial preparation for blastocyst implantation is a localized increase in capillary permeability, an event that is essentially inflammatory in character and thought to be a prerequisite for subsequent decidual tissue formation. Platelet-activating factor (PAF), chemically identified as 1-O-alkyl-2-acetyl-sn-glycero-3-phosphorylcholine, is a very potent vasoactive compound that recently has been implicated in the implantation process. In the present study, PAF binding sites are characterized in the rabbit uterus. Read More

Transfusion 1989 Jul-Aug;29(6):528-33

Department of Pharmacology, School of Medicine, University of Missouri-Columbia.

Human platelet concentrates were stored in polyolefin bags at 22 to 24 degrees C on a horizontal shaker for up to 8 days. At different intervals, aliquots of platelet-rich plasma (PRP) were removed aseptically and five variables, i.e. Read More

J Pharmacol Exp Ther 1989 Jul;250(1):293-300

Rhone-Poulenc Sante, C.R.V., Vitry-Sur-Seine, France.

High-affinity binding sites for platelet-activating-factor (PAF) have been identified in human polymorphonuclear leukocytes (PMNs). The aim of this investigation was to assess their functional relevance by characterizing PAF-induced elastase release, an enzyme present in azurophilic granules. At 37 degrees C, maximal release (measured with a spectrofluorimetric method) was achieved with 0. Read More

J Pharmacol Methods 1988 Nov;20(3):237-53

Department of Pharmacology and Chemotherapy, Roche Research Center, Hoffmann-La Roche Inc., Nutley, New Jersey 07110.

High-affinity, stereoselective, and ligand-selective specific binding of 3H-labeled platelet-activating factor (PAF) to its receptor on the dog platelet is reproducible over wide mass and concentration ranges of [3H]PAF. The [3H]PAF specific binding can be competitively inhibited by low picogram amounts of nonlabeled PAF. These observations have led to the formulation of radioligand competitive binding methodology for the detection and estimation of PAF in a biological lipid sample and the quantitative evaluation of PAF-receptor antagonism. Read More

Thromb Res 1988 Jun;50(6):789-802

Department of Pharmacology and Chemotherapy, Hoffmann-La Roche Inc., Roche Research Center, Nutley, New Jersey 07110.

Binding of 3H-labeled 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine (platelet-activating factor; PAF) to the intact, washed canine platelet has been defined and characterized as being specific and receptor-mediated. Under the conditions described, specific binding to 2 X 10(7) canine platelets reached saturation within 10 min at a [3H]PAF concentration of approximately 0.4 nM. Read More

J Pharmacol Exp Ther 1988 Feb;244(2):709-15

Rhône-Poulenc Santé, Centre de Recherche de Vitry, Biology Department, Vitry-sur-Seine, France.

In human polymorphonuclear leukocytes (PMNs), the tritiated platelet activating factor ([3H]PAF) labels in a saturable manner a single class of binding sites with a Kd of 3.5 +/- 0.5 nM (n = 7) and a maximum binding capacity (Bmax) of 206 +/- 13 fmol/2. Read More

Eur J Pharmacol 1987 Oct;142(3):331-41

INSERM U.200, Université Paris-Sud, Clamart, France.

Intact platelets incubated at 20 degrees C in the presence of 0.25% (w/v) bovine serum albumin (BSA) bound [3H]paf-acether in a concentration-dependent (0-6.5 nM) manner. Read More

J Clin Invest 1986 Aug;78(2):381-8

Human polymorphonuclear neutrophils rapidly incorporated radiolabeled platelet-activating factor, 1-O-[hexadecyl-9, 10-3H2]-2-acetyl-sn-glycero-3-phosphocholine ([3H]PAF), and then metabolized it into its sn-2-fatty acyl derivative. Fractionation of radiolabel-pretreated cells over Percoll gradients revealed that virtually all of the intact [3H]PAF was located in nongranule membranes that were enriched with alkaline phosphatase and cell surface glycoproteins. While still membrane associated, the ligand was rapidly converted to its acyl derivative and then more slowly transferred to specific granules and, to a lesser extent, azurophilic granules. Read More