Objective: Through researching the effection of Naohuan Dan(NHD) on behavior and the expression of β-amyloid precursor protein (APP)

peptidyl- prolyl cis-trans isomerase A (Pin1) and high mobility group protein Bl (HMGB1) mRNA in the hippocampus of Senescence Accelerrated Mouse SAMP/8

this work discusses partially the mechanism of traditional Chinese medicine NHD with respect to its effectiveness to treat Alzheimer's disease. Method: Sixty six-months old SAMP/8 mice were randomly divided into NHD low and high dose group and model group

10 six-months old SAMR/1 were served as a normal control group. The mice were administered with NHD intragastricly at the dose of 84

21 g·kg-1 per day for 8 weeks respectively

while distilled water in the model group and normal control group at the dose of 10 mL·kg-1.8 each analyzed the parameter of place navigationtest and spatial probe test by Morris water maze

then stripped out whole brain under sterile condition

the hippocampus were taken out to expression of APP

Pin1

HMGB1 mRNA by real time quantitative PCR (qRT-PCR). Result: 6 month old male SAMP/8 learning and memory ability was significantly lower than the same month-old SAMR/1 male

specific performance: the escape latency was significantly increased from the second day

the time of stopping on original platform quadrant was shortened. The SAMP/8's escape latency was significantly shortened(P<0.05). The memory retention in SAMR/1 mice and mice after NHD treatment was stronger than SAMP/8

especially the high dose NHD group was obvious(P<0.05).The relative expression of APP

Pin1

HMGB1 mRNA was statistical significant difference.In the model group

the level of APP mRNA increased compared with the normal control group(P<0.05); the level of APP mRNA of NHD group decreased compared with the model group(P<0.05). In the model group

the level of Pin1 mRNA decreased compared with the normal control group(P<0.05); the level of Pin1 mRNA of NHD group increased compared with the model group(P<0.05); In the model group

the level of HMGB1 mRNA increased compared with the normal control group(P<0.05); the level of HMGB1 mRNA of NHD group decreased compared with the model group(P<0.05);The effects in the NHD high dose group were all better than those in the low dose group for APP mRNA

Pin1 mRNA and HMGB1 mRNA. Conclusion: Naohua Dan treat SAMP/8 of the more recognized animal model of AD for 8 weeks.Behavior detection was found that Naohuan Dan can improve the learning ability

memory impairment of the SAMP/8.The increased level of APP and HMGB1 mRNA and the decreased level of Pin1 mRNA in the SAMP/8 mice

which probably is part of pathology of Alzheimer's disease. Naohuan Dan can block amyloid plaques and nerve fibers tangles from source through decreacing the APP and HMGB1 level and increscing the Pin1 level.This may be one of the major action points of the treatment of AD by Nanhuan Dan.