Objective     To study the activities of the alcoholic extract from

Fructus Polygoni Orientalis

(EFPO) against antioxidation.      Methods     The peroxidation in homogenate of rat heart

liver and kidney was induced by ·OH generation system Fe

2+

+ascorbic acid. Malondialdehyde (MDA) was determined by T

BA colorimetric method. Superoxide (O

2

-

) from zymosan-stimulated neutrophils of rat was measured by NBT reduction method. H

2

O

2

-caused hemolysis of erythrocytes was measured by spectrometry.       Results     MDA in homogenate of heart

liver and kidney of rat that induced by ·OH generation system Fe

2+

+ascorbic acid was inhibited by 6.3

12.5

25

50

100

200 μg/L EFPO; IC

50

of EFPO to MDA in heart

liver and kidney was 31.8

32.5 and 40.2 μg/L respectively and its dose-effect relation was of negative relativity and the relative coefficient was -0.886

-0.874 and -0.918 (all

P

<

0.01). O

2

-

generation from zymosan-stimulated neutrophils of rat was inhibited by EFPO; IC

50

of EFPO to O

2

-

generation was 31.9 μg/L and its dose-effect relation was of negative relativity and the relative coefficient was -0.873 (

P

<

0.01). H

2

O

2

-caused hemolysis of erythrocytes was inhibited by EFPO. IC

50

of EFPO to erythrocyte hemolysis was 56.2 μg/L and its dose-effect relation was of negative relativity and the relative coefficient was -0.888(

P

<

0.01).       Conclusion     EFPO exerts its antioxidation by scavenging ·OH

O

2

-

and H

2

O

2

in biological system.