title: Antioxidant effects of polyphenols in chocolate on low-density lipoprotein both in vitro and ex vivo.
abstract: Cacao is rich in polyphenols such as (-)-epicatechin, and a colored component of cacao (cacao-red) is polyphenol, which is an antioxidant. These properties stimulated an investigation of the effects of cacao liquor polyphenols (CLP) on low-density lipoprotein (LDL) oxidation. The 2.2 '-azobis(4-methoxy-2,4-dimethylvaleronitrile) (AMVN-CH2O)-induced oxidizability of LDL was assessed by monitoring the absorbance at 234 nm. In vitro. 0.1-0.5 mg/dL CLP prolonged the oxidation lag time of LDL in a dose-dependent manner. Compared with the controls, it was prolonged 1.7-fold in the presence of 0.1 mg/dL CLP, 2.9-fold at 0.2 mg/dL, 3.8-fold at 0.3 mg/dL, 5.4-fold at 0.4 mg/dL, and 6.4-fold at 0.5 mg/dL. Furthermore, we enlisted 13 male volunteers to consume 35 g delipidated cocoa. Venous blood samples were taken before and at 2 h and 4 h after consuming the cocoa. The oxidation lag time of LDL before cocoa ingestion was 59.0 +/- 6.3 min, but it was prolonged at 2 h after cocoa (68.3 +/- 6.0 min); before returning to the initial lag time (61.7 +/- 5.7 min) before consumption. Thus we have shown that cocoa inhibited LDL oxidation both in vitro and ex vivo.
authors.affiliation: Internal Medicine I, National Defense Medical College, Tokorozawa, Saitama, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Hirano
authors.forename: N
authors.initials: N
authors.lastname: Osakabe
authors.forename: A
authors.initials: A
authors.lastname: Iwamoto
authors.forename: A
authors.initials: A
authors.lastname: Matsumoto
authors.forename: M
authors.initials: M
authors.lastname: Natsume
authors.forename: T
authors.initials: T
authors.lastname: Takizawa
authors.forename: O
authors.initials: O
authors.lastname: Igarashi
authors.forename: H
authors.initials: H
authors.lastname: Itakura
authors.forename: K
authors.initials: K
authors.lastname: Kondo
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000494:pharmacology* / Q000627:therapeutic use; D001161:Arteriosclerosis / Q000097:blood / Q000517:prevention & control*; D001391:Azo Compounds / Q000494:pharmacology; D002099:Cacao / Q000737:chemistry*; D008078:Cholesterol, LDL / Q000097:blood / Q000187:drug effects* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005419:Flavonoids; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D009570:Nitriles / Q000494:pharmacology; D010084:Oxidation-Reduction; D010636:Phenols / Q000494:pharmacology* / Q000627:therapeutic use; D011108:Polymers / Q000494:pharmacology* / Q000627:therapeutic use; D059808:Polyphenols; D013053:Spectrophotometry; D013997:Time Factors
chemical_list: D000975:Antioxidants; D001391:Azo Compounds; D008078:Cholesterol, LDL; D005419:Flavonoids; D009570:Nitriles; D010636:Phenols; D011108:Polymers; D059808:Polyphenols; C055792:2,2'-azobis(2,4-dimethylvaleronitrile)