• Natural Product Sciences
• /
• v.11 no.3
• /
• pp.131-135
• /
• 2005

Methanolic extracts of ninety-five medicinal plants were screened for platelet-activating factor (PAF) receptor binding inhibitory activity using rabbit platelet. Alpinia officinarum, Belamcanda chinensis, Leonurus heterophyllus, Pinus densiflora, Polygonatum sibiricum and Sambucus williamsii showed significant inhibitory effects on the platelet-activating factor (PAF) receptor binding.

• Natural Product Sciences
• /
• v.2 no.2
• /
• pp.86-89
• /
• 1996

Methanolic extracts of 25 species of Malaysian medicinal plants were screened for platelet-activating factor (PAF) receptor binding activity using rabbit platelet. Extracts of Cinnamomum sintoc, Ixonanthes iconsandra, Paederia foetida, Piper aduncum, Premna integrifolia, Ardisia crispa, and Ardisia elliptica showed significant inhibitory effect on the platelet-activating factor (PAF) receptor binding.

• Korean Journal of Medicinal Crop Science
• /
• v.13 no.4
• /
• pp.178-181
• /
• 2005

Methanolic extracts of fifteen Chinese medicinal plants were screened for platelet-activating factor (PAF) receptor binding inhibitory activity using rabbit platelet. Campsis grandiflora, Dalbergia odorifera, Vaccaria segetalis and Zanthoxylum nitidum showed significant inhibitory effects on the platelet-activating factor (PAF) receptor binding. Campsis grandiflora, Dalbergia odorifera, Vaccaria segetalis and Zanthoxylum nitidum inhibited 52%, 56%, 70%, and 66% respectively at the concentration of 0.2 mg/ml.

• Archives of Pharmacal Research
• /
• v.20 no.1
• /
• pp.80-84
• /
• 1997

Substituted cinnamoyl-tyramine derivatives were synthesized by DCC-coupling of substituted cinnamic acid with tyramine or tyramine methyl-1-ether to evaluate PAF-receptor binding antagonistic activities and inhibitory activities on PAF-induced platelet aggregation with interest on structure-activity relations. The results show that 3,4-dimethoxy-cinnamoyl tyramine-amide or its methyl ether have significant PAF-receptor binding antagonistic activity and platelet anti-aggregatory activities.

• Korean Journal of Pharmacognosy
• /
• v.25 no.2
• /
• pp.167-170
• /
• 1994

The platelet activating factor (PAF) is a newly discovered chemical mediator, the chemical structure of which is 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine. Since PAF has potent and broad activities, its pathophysiological roles have received much attention. To develope a new PAF antagonist from medicinal plants, extracts of twenty medicinal herb were screened using PAF receptor binding, $[^{14}C]$ serotonin release and platelet aggregation.

• Natural Product Sciences
• /
• v.7 no.2
• /
• pp.33-37
• /
• 2001

Methanol extracts of eighty Chinese medicinal plants were investigated for platelet-activating factor (PAF) receptor binding inhibitory activity using rabbit platelet. Extracts of Cratoxylon ligustrinum, Kalimeris indica, Euonymus japonica, Ophiopogon japonicus, Gleditsia sinensis, Clausena lansium, Agave sisalana were found to exhibit significant inhibitory effects. Chloroform partition of the Methanol extract of Kalimeris indica was further fractionated by column chromatography to afford one strong active subfraction with 93.6% inhibition at a concentration of $100{\mu}g/ml$.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1995.04a
• /
• pp.60-60
• /
• 1995

새로운 혈소판 활성화인자 (PAF) 수용체 결합 저해활성 유효성분인 pinusolide ($IC_{50}$/=2.5$\times$$10^{-7}$M)와 arctigenin($IC_{50}$/=5.2$\times$$10^{-6}$M)을 측백엽(Biota orientalis)과 우방자(Arctium lappa)로부터 분리하여 이미 보고한 바 있다. PAF 수용체에 대한 구조활성 상관관계를 규명하고자 또한 용해도가 우수한 강력한 PAF 길항제를 개발하고자 이 길항제들의 유도체들을 다양한 유기화학반응을 이용하여 합성하였고 in vitro PAF receptor binding assay로 그 활성의 강도를 비교 검토하였다. 그 결과, lactone ring 부분은 unsaturated lactone이 saturated lactone보다 활성이 강하였고 ring이 개열되면 활성이 현저히 감소하였다. pinusolide 경우 exocylclic double bond 부분은 sp$^2$구조의 hydrophobic한 유도체가 활성이 강하였으며, methyl ester 부분은 hydrophobic한 유도체가 활성이 강하였다. Arctigenin의 경우 aromatic unit가 hydrophobic할수록 활성이 강하였다.

• YAKHAK HOEJI
• /
• v.39 no.1
• /
• pp.10-13
• /
• 1995

As a continuation of the previous studies, a third group of thirty five hot aqueous extracts from natural products were screened for platelet activating factor(PAF) receptor binding antagonistic acitivities using rabbit platelet. The results demonstrate that Arctium lappa is potential source of PAF antagonist.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1998.11a
• /
• pp.177-177
• /
• 1998

In the previous report, tetrandrine (TET) and fangchinoline (FAN) showed antithrombotic and antiplatelet aggregation activities. The present study was undertaken to investigate the effects of tetrandrine and fangchinoline on human platelet aggregation, formation of thromboxane B$_2$ and coagulation of platelet poor plasma. TET and FAN inhibited platelet activating factor (PAF) induced human platelet aggregation, but didn't inhibit the specific binding of PAF to its receptor. Meanwhile, TET and FAN also inhibited PAF, thrombin and arachidonic acid induced thromboxane B$_2$ formation in human washed platelets. In addition, neither TET nor FAN showed any anticoagulation activities in the measurement of the activated partial thromboplastin time (APTT), prothrombin time (PT) and thrombin time (TT) using human platelet poor plasma. These results suggest that antithrombotic effects of TET and FAN in mice may be mainly related to the antiplatelet aggregation activities, and the antiplatelet aggregation effects may be related to the intracellular messenger system such as TXA$_2$ formation etc., but not to the binding of PAF to PAF-receptor on the platelet membrane directly.

• Biomolecules & Therapeutics
• /
• v.14 no.3
• /
• pp.160-165
• /
• 2006

Since platelet-activating factor (PAF) is involved in inflammation, allergic response and anaphylactic shock, PAF receptor antagonists may have potential for controlling these disease conditions. The extract of the leaves of Ginkgo biloba having a higher content of terpenoids (12%) with flavonoids (24%) (YY1224) was prepared in order to obtain the increasing PAF antagonistic activity. As expected, YY1224 showed a higher PAF antagonistic binding affinity ($IC_{50}\;=\;0.09\;{\mu}g/ml$) using $[^3H]PAF$ and rabbit platelets as ligand and receptor source, compared with an $IC_{50}$ of $>\;100\;{\mu}g/ml$ by Egb 761, a standardized extract. YY1224 also showed a higher inhibitory activity against PAF-induced platelet aggregation and NO production from lipopolysaccharide-treated RAW 264.7 cells. In addition, it protected PAF-induced death in mice by oral administration at 15 mg/kg. All these results suggest that YY1224 may show favorable effects on PAF-related disorders.