Objective: To discuss the curative effects of Bupi Yishen decoction in treating Alzheimer's disease and to investigate its influence on oxidative stress. Method: Sixty-six patients were randomly divided into the control group (31 cases) and the observation group (35 cases). Patients in the control group received 10 mg donepezil hydrochloride tablets once daily. Patents in the observation group received 1 does Bupi Yishen decoction

once daily. All patients in two groups received 6 months of treatment. Scores of minimum mental state examination (MMSE)

Alzheimer's disease assessment scale-cognitive subscale (ADAS-cog)

activity of daily living scale (ADL) and traditional Chinese medicine syndrome were conducted. Levels of oxide dismutase (SOD)

malondialdehyde (MDA)

total antioxidant capacity (T-AOC)

8-heterogeneous prostaglandin F2α(8-iso-PGF2α) and oxidized low density lipoprotein (ox-LDL) were detected before and after the therapy. Result: The efficacy scores of MMSE and ADAS-cog in the observation group were higher than those in the control group (P<0.05). Scores of traditional Chinese medicine syndromes

ADL

ADAS-cog in the observation group were lower than those in the control group (P<0.01)

while the MMSE score was higher than that in the control group (P<0.01). After treatment

levels of MDA

8-iso-PGF2a and ox-LDL were lower

and levels of SOD and T-AOC were higher in the observation group than those in the control group (P<0.01). Conclusion: Bupi Yishen decoction could enhance cognitive function and life self-care ability in patients with mild to moderate AD. Its curative effects are superior to donepezil hydrochloride tablets. Its mechanism may be related to antioxidant and antagonizing free radical damage.