Inhibitory effects of balsamic vinegar on LDL oxidation and lipid accumulation in THP-1 macrophages

Oxidized low-density lipoprotein (LDL) is believed to contribute to atherosclerosis in part by being taken up into macrophages via scavenger receptors, thus accounting for foam cells. Balsamic vinegar is made from grapes and generally consumed in the Mediterranean region. In this study, we investigated the preventive effects of balsamic vinegar on LDL oxidation and foam cell formation. Balsamic vinegar had stronger 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging abilities and higher polyphenol concentrations than rice vinegar. Balsamic vinegar dramatically inhibited LDL oxidation by azoradicals and endothelial cell-mediated oxidation in vitro. Further, we assessed the anti-oxidative effect against LDL after balsamic vinegar consumption in human subjects. Balsamic vinegar prolonged the LDL oxidation lag time and decreased lipid peroxide (LPO) and lyso-phosphatidylcholine (LPC) in LDL particles. We next examined the effect of balsamic vinegar on foam cell formation. Oil red O staining showed that balsamic vinegar inhibited oxidized LDL-induced foam cell formation in THP-1 macrophages. The concentrations of intracellular triglycerides and total cholesterols were reduced in the presence of balsamic vinegar. In addition, balsamic vinegar decreased the mRNA and protein expression level of scavenger receptors in THP-1 macrophages. These results showed that balsamic vinegar contained abundant polyphenols and inhibited LDL oxidation and oxidized LDL-induced foam cell formation by decreasing the expression of scavenger receptors.