title: Inhibitory activities of compounds from the twigs of Garcinia hombroniana Pierre on human low-density lipoprotein (LDL) oxidation and platelet aggregation.
abstract: The methanol extract of the twigs of Garcinia hombroniana, which showed strong LDL antioxidation and antiplatelet aggregation activities, was subjected to column chromatography to obtain 3,5,3',5'-tetrahydroxy-4-methoxybenzophenone, 1,7-dihydroxyxanthone and eight triterpenoids, garcihombronane B, D, E and F, friedelin, glutin-5-en-3β-ol, stigmasterol and lupeol. The structures of the compounds were elucidated by spectroscopic methods. The compounds were evaluated for their ability to inhibit copper-mediated LDL oxidation and arachidonic acid (AA)-, adenosine diphosphate (ADP)-, collagen-induced platelet aggregation in vitro. Among the compounds tested, 3,5,3',5'-tetrahydroxy-4-methoxybenzophenone and 1,7-dihydroxyxanthone showed strong inhibitory activity on LDL oxidation with half-maximal inhibitory concentration (IC(50)) values of 6.6 and 1.7 µM, respectively. 3,5,3',5'-Tetrahydroxy-4-methoxybenzophenone exhibited strong activity on AA-, ADP- and collagen-induced platelet aggregation with IC(50) values of 53.6, 125.7 and 178.6 µM, respectively, while 1,7 dihydroxyxanthone showed significant and selective inhibitory activity against ADP-induced aggregation with IC(50) value of 5.7 µM. Of the triterpenoids tested, garcihombronane B showed moderate activity against LDL oxidation and garcihombronane D and F showed selective inhibition on ADP-induced platelet aggregation.
authors.affiliation: Drug and Herbal Research Center, Faculty of Pharmacy, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia.
authors.forename: Fadlina Chany
authors.initials: FC
authors.lastname: Saputri
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Jantan
mesh_terms: D000328:Adult; D000368:Aged; D000975:Antioxidants / Q000494:pharmacology*; D029760:Garcinia / Q000737:chemistry*; D006801:Humans; D008077:Lipoproteins, LDL / Q000378:metabolism*; D008875:Middle Aged; D010084:Oxidation-Reduction; D010936:Plant Extracts / Q000494:pharmacology*; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D055815:Young Adult
chemical_list: D000975:Antioxidants; D008077:Lipoproteins, LDL; D010936:Plant Extracts; D010975:Platelet Aggregation Inhibitors