Objective: In order to investigate the effect of ultra-filtration extract from Angelica Sinensis Radix and Hedysari Radix(Angelica Sinensis Radix:Hedysari Radix 1:5) on the memory ability and brain neurotransmitters in old rats. Method: 12 healthy male Wistar rats with 3-months old were selected for the youth control group (A)

and 48 natural aging male Wistar rats with 24-months old were selected and randomly divided into four groups:the old control group (B)

5×104 Da molecular of UFE-AH group (C)

1×105 Da molecular of UFE-AH group (D)

and 2×105 Da molecular of UFE-AH group (E);Group A

B were given normal saline (7 mL·kg-1·d-1) and Group C

D

E were respectively given with 5×104 Da(1.87 g·kg-1·d-1)

1×105(2.14 g·kg-1·d-1)

2×105 Da(2.47 g·kg-1·d-1)molecular of UFE-AH by gavage. After 10 weeks

the learning and memory ability were measured

and heir brain tissue was observed (hippocampus and cortex) by microscope

the contents of the central neurotransmitter acetylcholine(Ach)

the monoamine neurotransmitter 5-hydroxytryptamine(5-HT)

dopamine(DA)

and norepinephrine(NE) were tested in the brains. Result: The learning and memory ability in group B were lower than that of group A

and the contents of Ach

5-HT

DA

and NE in the brain tissue also decreased; Compared with group B

the contents of Ach

5-HT

DA

and NE group C

D and E increased

and the increase extent in group D was more significant than that in group C and E. Conclusion: Ultra-filtration extract from Angelica Sinensis Radix and Hedysari Radix Polybotrys can improve the learning and memory ability of old age rats

which may be related to the increase of the Ach

5-HT

DA

and NE in the brain tissue

and the effect of 1×105 Da molecular weight group is better than others molecular weight group.