In vitro inhibitory effect of Rubraxanthone isolated from Garcinia psrvifolia on platelet- Activating factor receptor binding

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 18.2 microM. The IC 50 values of m...

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Bibliographic Details
Main Authors: Jantan, Ibrahim, Md Pisar, Mazura, Idris, Muhammad Sum, Bakhtiar, M. Taher, Mat Ali, Rasadah
Format: Article
Language:English
Published: Thieme Verlagsgruppe 2002
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Online Access:http://irep.iium.edu.my/12052/
http://irep.iium.edu.my/12052/
http://irep.iium.edu.my/12052/1/Plantamedica.pdf
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Summary: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 18.2 microM. The IC 50 values of macluraxanthone, 6-deoxyjacareubin, 2-(3-methylbut-2-enyl)-1,3,5-trihydroxyxanthone, 2-(3-methylbut-2-enyl)-1,3,5,6-tetrahydroxyxanthone and 1,3,5-trihydroxy-6,6'-dimethylpyrano(2',3':6,7)-4-(1,1-dimethylprop-2-enyl)-xanthone were also determined for comparison. In the course of our study on structure-activity relationship of xanthones, the results revealed that a geranyl group substituted at C-8 was beneficial to the binding while a hydroxylated prenyl group at C-4 resulted in a significant loss in binding to the PAF receptor.