Antioxidant effects of polyphenols in chocolate on low-density lipoproteinboth in vitro and ex vivo

Cacao is rich in polyphenols such as (-)-epicatechin, and a colored compone nt of cacao (cacao-red) is polyphenol, which is an antioxidant. These prope rties stimulated an investigation of the effects of cacao liquor polyphenol s (CLP) on low-density lipoprotein (LDL) oxidation. The 2,2'-azobis(4-metho xy-2,4-dimethylvaleronitrile) (AMVN-CH3O)-induced oxidizability of LDL was assessed by monitoring the absorbance at 234 nm. In vitro, 0.1-0.5 mg/dL CL P prolonged the oxidation lag time of LDL in a dose-dependent manner. Compa red 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 be fore 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 oxid ation both in vitro and ex vivo.