Objective: To observe the influence of Ditan Tang on the content of β-amyloid(Aβ1-42) and expressions of presinilin(PS)-1

PS-2 in hippocampus of senile mild cognitive impairment(MCI) rats. Method: Sixty 13 months old rats were randomly divided into normal group

model group

Donepezil 0.9 mg·kg-1 group

the high dose and low dose groups(8.55

4.28 g·kg-1) of Ditan Tang

12 three months old rats were as young normal group. The senile MCI rats model was established by subcutaneous injection of D-galactose for 8 weeks and fed with semi-high-fat diet for 4 weeks in model group

Donepezil group

the high dose Ditan Tang group

and low dose Ditan Tang group. The learning and memory ability was tested by Morris water maze test in rats. Enzyme linked immunosorbant assay(ELISA) method was used to detect the levels of Aβ1-42in hippocampus. Levels of PS-1 and PS-2 in hippocampus were detected by immunohistochemistry. Result: Compared with normal group

the escape latency in model group rats was significantly prolonged (P<0.01)

the content of Aβ1-42 in hippocampus increased significantly (P<0.01)

and the expressions of PS-1 and PS-2 in hippocampus also increased (P<0.05).Compared with model group

the escape latency of Ditan Tang group(high dose and low dose) were significantly shorten (P<0.01

P<0.05). The content of Aβ1-42 in hippocampus on both high and low dose group of Ditan Tang decreased (P<0.01

P<0.05). The expressions of PS-1 and PS-2 in hippocampus on both high and low dose group decreased significantly (P<0.01). Conclusion: The Ditan Tang may decrease the contents of Aβ1-42 and the expressions of PS-1 and PS-2 in hippocampus. It might be reason of improving cognitive dysfunction in rats.