Objective: To establish three types of parkinsonian mice models

observe the effect of Qianzheng San extract on mice behavior and explore possible mechanisms of its actions. Method: ①The Kunming mice were randomly divided into four groups:model group

Qianzheng San low dose group and high dose group (1.7

5.0 g·kg-1)

positive drug group (benzhexol hydrochloride

3.35 mg·kg-1). The mice in the treatment groups received the corresponding medicines by intragastric administration for 4 days. 1 hour after the last administration

all mice were injected with arecoline hydrobromide (25 mg·kg-1) or oxotremorine (0.15 mg·kg-1). The incubation period and duration time of tremor were recorded. ②C57BL/6 mice were randomly divided into five groups:normal group

model group

Qianzheng San low dose group and high dose group (1.7

5.0 g·kg-1)

positive drug group (madopar

50 mg·kg-1). All mice except normal group were injected with 1-methyl-4-phenyl-1

2

3

6-tetrahydropy-ridine(MPTP

30 mg·kg-1) for 5 consecutive days. From 6th day

the mice in treatment group received Qianzheng San extract or madopar by intragastric administration for 7 days. After the last treatment

behavior changes of the mice were detected and ultrastructure changes of substantia nigra neurons were observed by electron microscope. Result: ①After injection of arecoline hydrobromide or oxotremorine

the mice exhibited obvious tremor. Compared with the model group

Qianzheng San extract high-dose group significantly prolonged the incubation period of tremor (P<0.05)

and Qianzheng San low dose group and high dose group significantly shortened the duration time of tremor (P<0.01). ②Compared with the model group

the MPTP-treated mice displayed a significant decrease in spontaneous motor activity and ultrastructure of substantia nigra neuron was obviously damaged. However

Qianzheng San extract treatment significantly increased autonomic activities

prolonged incubation period and shortened the pole-climbing time (P<0.05)

and reduced the damage of ultrastructure of substantia nigra neurons. Conclusion: Qianzheng San extract could effectively suppress tremor and improve motor dysfunction in PD mice models

whose mechanism may be associated with reducing mitochondrial damages and protecting neurons.