title: Chemical constituents of Morinda citrifolia fruits inhibit copper-induced low-density lipoprotein oxidation.
abstract: The oxidative modification of low-density lipoprotein (LDL) plays an important role in the genesis of arteriosclerosis. The present study focused on the effects of the fruits of Morinda citrifolia on preventing arteriosclerosis. The MeOH extract and CHCl(3)-, EtOAc-, n-BuOH-, and H(2)O-soluble phases derived from the fruits of M. citrifolia were evaluated for their inhibitory activity on copper-induced LDL oxidation by the thiobarbituric acid-reactive substances (TBARS) method. The MeOH extract and EtOAc-soluble phase showed 88 and 96% inhibition, respectively. Six lignans were isolated by repeated column chromatography from the EtOAc-soluble phase. These compounds were determined by spectroscopic analysis to be 3,3'-bisdemethylpinoresinol (1), americanol A (2), americanin A (3), americanoic acid A (4), morindolin (5), and isoprincepin (6), of which 4 and 5 are novel compounds. These compounds inhibited copper-induced LDL oxidation in a dose-dependent manner. 1, 2, 5, and 6 exhibited remarkably strong activities, which were the same or better than that of the known antioxidant 2,6-di-tert-butyl-p-cresol. The IC(50) values for 1, 2, 5, and 6 were 1.057, 2.447, 2.020, and 1.362 microM, respectively. The activity of these compounds is mainly due to their number of phenolic hydroxyl groups.
authors.affiliation: Faculty of Pharmaceutical Sciences and High Technology Research Center, Kobe Gakuin University, Nishi-ku, Kobe 651-2180, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Kamiya
authors.forename: Yohei
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Hanani
authors.initials: H
authors.lastname: Endang
authors.forename: Mansur
authors.initials: M
authors.lastname: Umar
authors.forename: Toshiko
authors.initials: T
authors.lastname: Satake
mesh_terms: D001161:Arteriosclerosis / Q000209:etiology / Q000517:prevention & control; D003300:Copper / Q000494:pharmacology*; D005638:Fruit / Q000737:chemistry*; D017705:Lignans / Q000302:isolation & purification / Q000494:pharmacology; D015227:Lipid Peroxidation / Q000187:drug effects*; D008077:Lipoproteins, LDL / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D000432:Methanol; D032066:Morinda / Q000737:chemistry*; D010084:Oxidation-Reduction; D010936:Plant Extracts / Q000494:pharmacology*; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis
chemical_list: D017705:Lignans; D008077:Lipoproteins, LDL; D010936:Plant Extracts; D017392:Thiobarbituric Acid Reactive Substances; D003300:Copper; D000432:Methanol