Objective: To study the effect of Cistanche deserticola polysaccharides herb (CDPS) on learning and memory ability of D-galactose(D-gal) induced aging mice and possible mechanisms. Method: Ninety mice were randomly assigned into control group

model group

CDPS low

middle and high dose group (25

50

100 mg·kg-1)

positive control group

15 mice in each group. The model

CDPS and positive control groups were injected 150 mg·kg-1 D-gal subcutaneously to establish aging-mouse model

and the control group was given the same volume of saline water;meanwhile

the CDPS groups were administered orally corresponding concentrations of CDPS liquid and positive control group was given 10 mg·kg-1 piracetam

while the control and the model groups were given the same volume of distilled water.After six weeks of continuous administration

the water maze performance and step-down passive avoidance test were applied to determine learning and memory ability of mice. Moreover

superoxide dismutase(SOD) activity and malondialdehyde(MDA) content in brain tissue of mice were detected by kits. Morphological changes of neurons in the hippocampus of brain tissue were observed with HE staining. Furthermore

the expression level of cAMP response element binding protein(CREB) was examined by immunohistochemistry. Result: In water maze performance

CDPS(25

50

100 mg·kg-1) significantly decreased latency and the first time arrived platform and increased travel times in D-gal-treated mice. In step-down passive avoidance test

the step down latencywas significantly prolonged and the number of errors was decreased in CDPS(25

50

100 mg·kg-1)groupcompared to those in the D-gal-control group. In addition

CDPS(25

50

100 mg·kg-1) significantly increased the activity of SOD and decreased the level of MDA in the brain tissues of D-gal-treated mice. At the same time

CDPS increased the number of neuron in hippocampal CA1 of mouse brain and ameliorated the pathological changes according to HE staining and CDPS(25

50

100 mg·kg-1) increased CREB expression levels in the hippocampus of mice comparing with those in D-gal-control group. Conclusion: CDPS canimprove the learning and memory ability of D-gal induced aging model mice

and the mechanism may be related to increasing CREB expression.