ObjectiveTo investigate the possible mechanism of Bushen Huoxue Granule （补肾活血颗粒， BHG） in treating Parkinson's disease （PD） from the perspecitve of dopamine （DA） homeostasis. MethodsSeventy-two mice were randomly divided into blank group， model group， madopar group and BHG low-， medium- and high-dose groups， with 12 mice in each group. Except for the blank group， all mice were administered intraperitoneal injections of 1-methyl-4-phenyl-1，2，3，6-tetrahydropyridine （MPTP） for 7 consecutive days to induce a PD model. On the day following the injection， BHG low-， medium- and high-dose groups were administered BHG at doses of 1.25， 2.5， and 5.0 mg/（g·d） by oral gavage， respectively， while the madopar group received madopar tablets at dose of 0.093 8 mg/（g·d） by oral gavage. The blank group and the model group were given 0.2 ml/10 g of distilled water by gavage. All treatments were given once daily for 14 days. Open field test， pole climbing test and grip test were used to evaluate the behavior of mice in each group. Immunohistochemistry was used to detect the expression of tyrosine hydroxylase （TH） in striatum. Nissl staining was used to detect the activity of striatal neurons. The contents of DA and 3,4-dihydroxyphenylacetic acid （DOPAC） in striatum were detected by ultra performance liquid chromatography tandem mass spectrometry. The number and volume of synaptic vesicles were observed by transmission electron microscope. The expression of vesicular monoamine transporter 2 （VMAT2） in striatum was detected by immunofluorescence. Western Blot was used to detect the expression of extracellular signal-regulated kinase （ERK）， phosphorylated ERK （p-ERK）， cAMP response element-binding protein （CREB）， phosphorylated CREB （p-CREB） and VMAT2 in striatum. ResultsCompared to the blank group， mice in the model group showed a significant decline in total distance and average speed in the open field test， along with an increase in total resting time； in the pole test， both the time required for the mice to turn completely downward （T-turn） and the total time taken to reach the bottom of the pole （T-total） were prolonged； forelimb grip strength was reduced； in the striatum， the mean optical density of TH， the average fluorescence intensity of VMAT2 protein， and DA content all decreased， while the number of striatal neurons was reduced， and the DOPAC/DA ratio was elevated； the levels of p-ERK/ERK， p-CREB/CREB， and VMAT2 in the striatum significantly decreased （P＜0.01）； transmission electron microscopy revealed that both the number and volume of synaptic vesicles in striatal neurons were markedly reduced. Compared to the model group， mice in the madopar group and BHG low-， medium- and high-dose groups showed significant improvements in all the above indicators （P＜0.05 or P＜0.01）. Compared to madopar group， the BHG high-dose group exhibited increased DA content and elevated p-CREB/CREB ratio in the striatum （P＜0.05）. Compared to the BHG low-dose group， the BHG high-dose group showed increased total distance and mean velocity， decreased total resting time， T-turn， and T-total， as well as enhanced forelimb grip strength； moreover， the average fluorescence intensity of VMAT2 protein， DA content， p-ERK/ERK， p-CREB/CREB， and VMAT2 levels in the striatum were all significantly elevated （P＜0.05 or P＜0.01）. ConclusionBHG may restore DA homeostasis and alleviate the damage of dopaminergic neurons by regulating ERK/CREB/VMAT2 signaling pathway.