Oxygen free radicals have been implicated in mediating various patholo
gical processes such as ischemia, inflammatory diseases, diabetes, and
atherosclerosis. The antioxidant enzymes-superoxide dismutase (SOD),
catalase (CAT) and glutathione peroxidase (GPX)-play an important role
in scavenging oxidants and preventing cell injury. Aged Garlic Extrac
t (AGE) has been shown to prevent oxidant-induced injury of endothelia
l cells. The present study determined the effects of AGE on the genera
tion of hydrogen peroxide (H2O2) and superoxide anion (O-2(.)) and the
activity of three antioxidant enzymes in bovine pulmonary artery endo
thelial cells (PAEC). Confluent monolayers of PAEC were incubated with
AGE, and oxidative stress was triggered by hypoxanthine and xanthine
oxidase or H2O2. AGE exhibited both concentration- and time-dependent
suppression of H2O2 and O-2(.) generation, and it also significantly i
ncreased the activities of SOD, CAT and GPX. The results suggest that
AGE may be an effective antioxidant in preventing or treating disorder
s related to endothelial cell injury associated with free radicals. (C
) 1998 Elsevier Science Inc.