GARLIC COMPOUNDS PROTECT VASCULAR ENDOTHELIAL-CELLS FROM OXIDIZED LOW-DENSITY LIPOPROTEIN-INDUCED INJURY

Oxidation of low density lipoprotein (LDL) has been recognized as play ing an important role in the initiation and progression of atheroscler osis. In this study, the effects of aged garlic extract and one of its major compounds, S-allylcysteine, on oxidized LDL-induced cell injury were studied. Pulmonary artery endothelial cells were pre-incubated w ith the garlic extract (1, 2.5 and 5 mg mL(-1)) or S-allylcysteine (0. 1, 1, 10 and 20 mM) at 37 degrees C and 5% CO2 for 24 h, washed, and t hen exposed to 0.1 mg mL(-1) oxidized LDL for 24 h. Lactate dehydrogen ase release as an index of membrane damage, methylthiazol tetrazolium assay for cell viability and thiobarbituric acid reactive substances i ndicating lipid peroxidation were determined. Preincubation of endothe lial cells with the extract or S-allylcysteine significantly prevented membrane damage, loss of cell viability and lipid peroxidation. The d ata indicate that these compounds can protect vascular endothelial cel ls from injury caused by oxidized LDL, and suggest that they may be us eful for prevention of atherosclerosis.