Subscribe to RSS
DOI: 10.1055/s-2002-36343
In Vitro Inhibitory Effect of Rubraxanthone Isolated from Garcinia parvifolia on Platelet-Activating Factor Receptor Binding
Publication History
Received: April 5, 2002
Accepted: July 13, 2002
Publication Date:
20 December 2002 (online)
Abstract
Rubraxanthone and isocowanol isolated from Garcinia parvifolia Miq. were investigated for their inhibitory effects on platelet-activating factor (PAF) binding to rabbit platelets using 3 H-PAF as a ligand. Rubraxanthone showed a strong inhibition with IC50 value of 18.2 μM. The IC50 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.
References
- 1 Braquet P, Tougui L, Shen T Y, Vargaftig B B. Perspective in platelet activating factor research. Pharmacological Review. 1987; 39 97-145
- 2 Mallet A T, Cunningham F M. Structural identification of PAF in psoriatic scale. Biochemical Biophysical Research Communications. 1985; 126 192-8
- 3 Vargaftig B B, Braquet P G. PAF-acether today: relevance for acute experimental anaphylaxis. British Medical Bulletin. 1987; 43 312-35
- 4 Kloprogge E, Akkerman N. Binding kinetic of PAF-acether (1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) to intact human platelets. Biochemical Journal. 1984; 233 901
- 5 Goh S H, Jantan I, Gray A I, Waterman P G. Prenylated xanthones of Garcinia opaca . Phytochemistry. 1992; 31 1383-6
- 6 Goh S H, Jantan I. A xanthone from Calophyllum inophyllum . Phytochemistry. 1991; 30 366-7
- 7 Jantan I, Juriyati J, Warif N A. Inhibitory effects of xanthones on platelet activating factor receptor binding in vitro . Journal of Ethnopharmacology. 2001; 75 287-90
- 8 Ampofo S A, Waterman P G. Xanthones from three Garcinia species. Phytochemistry. 1989; 25 2351-5
- 9 Valone F H, Coles E, Reinhold V R, Goetzl E J. Specific binding of phospholipid platelet-activating factor by human platelets. Journal of Immunology. 1982; 129 1637-41
Ibrahim Jantan, PhD
Department of Pharmacy
Faculty of Allied Health Sciences
Universiti Kebangsaan Malaysia
Jalan Raja Muda Abdul Aziz
50300 Kuala Lumpur
Malaysia
Phone: +603-40405331
Fax: +603-26983271
Email: ibj@medic.ukm.my