Objective: To explore the influence of Hei Xiaoyao San on superoxide dismutase(SOD)

gluthathione peroxidase(GSH-Px) and malondialdehyde(MDA) of brain tissue and serum in Alzheimer's disease rat model induced by β-amyloid protein(Aβ25-35) fragments so as to discuss the role and mechanisms involved in Hei Xiaoyao San in the prevention and treatment of Alzheimer's disease(AD). Method: The SD rats (n=94) were randomly divided into sham surgery rats(n=16) group and model group (n=94)

and all rats of model group received water maze tests for 7 days. These eligible rats were randomly divided 5 groups

model group

positive control group

Hei Xiaoyao San high

medium and low dose groups

14 rats in each group. Aβ25-35fragments was injected into the hippocampus to damage brain neuron to make the rat's AD model. 7 days later

all rats of Hei Xiaoyao San group were orally administered Hei Xiaoyao San at low

medium and high doses (4.2

8.50

17.0 g·kg-1·d-1)

the positive control group was orally given huperzine A solution 0.02 mg·kg-1·d

model group and sham group received an equal volume double distilled water daily for 28 d. After the last administration

the rats were sacrificed and serum and brain samples collected

and the serum and brain homogenate stration of SOD

MDA

GSH-Px were examined by means of chemistry chromatometry. Result: Compared with the sham group

serum and brain tissue homogenate SOD

GSH-Px of model group decreased significantly

MDA content increased significantly(P<0.05). Compared with the model group

Hei Xiaoyao San obviously increased the activities of SOD and GSH-Px and reduced the content of MDA (P<0.05) in serum and brain tissue. Conclusion: Hei Xiaoyao San can protect rat's AD model from damage

and the mechanisms of which may be related to anti-free radicals.