GARLIC COMPOUNDS PROTECT VASCULAR ENDOTHELIAL-CELLS FROM HYDROGEN PEROXIDE-INDUCED OXIDANT INJURY

Oxygen radical injury and lipid peroxidation have been suggested as major causes of cancer, atherosclerosis and the aging process. In this study, we determined in vitro the effect of aged garlic extract (AGE) and one of its components, S-allyl cysteine (SAG), on hydrogen peroxide (H2O2)-induced oxidant injury using bovine pulmonary artery endothelial cells (PAEC). After overnight preincubation with AGE or SAG, PAEC monolayers were exposed to H2O2 for 3 h. Cell viability, lactate dehydrogenase (LDH) release and lipid peroxidation were measured to assess oxidant injury. Pretreatment with AGE at 2-4 mg/mL or SAC at 4 mg/mL significantly reversed the loss of cell viability induced by 50 and 100 mu m of H2O2. AGE or SAC also exhibited a dose-dependent inhibition of both LDH release and lipid peroxidation induced by 50 mu M of H2O2. The results show that both AGE and SAC can protect vascular endothelial cells from oxidant injury. The data thus suggest that these compounds may be useful for retardation of the aging process and for prevention of cancer and atherosclerosis