文档介绍：ABSTRACT: The antioxidant activity and free-radical and ac- tive oxygen-scavenging activity of burdock extracts were investi- gated. Of the solvents used for extraction, water yielded the greatest amount of extract that exhibited the strongest antioxi- dant activity. Water extracts of burdock (WEB) and hot water ex- tracts of burdock (HWEB) parable and marked ac- tivity on inhibition of linoleic acid peroxidation, indicating that heat treatment did not alter the antioxidant activity of WEB. WEB and HWEB produced signi?cantly lower ( P < ) malondialde- hyde (MDA) in both linoleic acid and liposome model systems than did the control. Moreover, mixtures of tocopherol (Toc), WEB, and HWEB exhibited a remarkable synergistic antioxidant effect in a liposome system; WEB and HWEB thus potentiated the action of Toc. Furthermore, WEB and HWEB displayed a marked inhibitory effect on lipid peroxidation of rat liver ho- mogenate in vitro . WEB and HWEB exhibited an 80% scaveng- ing effect on α, α-diphenyl- β-picrylhydrazyl radical and marked reducing power, indicating that WEB and HWEB act as primary antioxidants. Both extracts at a dose of mg exhibited a –% scavenging effect on superoxide and an % scavenging effect on hydrogen peroxide. They also showed a marked scavenging effect on the hydroxyl radical. These results revealed that WEB and HWEB are also active as oxyg