Inhibitory Effect of Chlorogenic Acid on Low-Density Lipoprotein Oxidation Induced by Cu ion

Chlorogenic acid, formed of an ester of caffeic acid and quinic acid, which is naturally abundant in many plant species, was used as a model O-dihydoxy phenolic compound. In the previous study, we have reported that the isolated constituent from Apocynum venetum leaves has an inhibitory effect on Cu-induced oxidative modification of low-density lipoprotein (LDL). Among them, chlorogenic acid showed the most potent anti-LDL oxidative activity than other compounds. For the reason, we investigated the inhibitory effect of the chlorogenic acid on Cu-induced oxidative modification of LDL, monitored a lag time in the conjugated-diene formation and TBARS formation, and measured TNBS free amino acid group, and form cell formation in vitro system. The TBARSand dieneformation were strongly inhibited by chlorogenic acid (0 ~ 100 μg / ml) with dose dependent manner. On the other hand, TNBS reactive lysine amino groups on LDL oxidation were protected by chlorogenic acidtreated cell group. Therefore, chlorogenic acid inhibited to cholesterol accumulation in the isolated peritoneal macrophage.