Objective To explore the protective effect of Anchanling serum on PCI2 cell injury induced by lactacystin and the possible mechanism.Methods The sem were obmined from rats with intragastric administration of Anchanling at small,medium and high doses.Lactacystin was used to induce proteasomal dysfunction in PCI2 cells,and the cell viability was evaluated with MTT assay.The PC 12 cells in exponential growth were divided into normal control,lactacystin injury and Anchanling-treated groups with corresponding treatments,and theexpressions of alpha-synuclein and tyrosine hydroxylase(TH)were assayed using immunohistochemical staining.Results The serum of rats with medium-dose Anchanling treatment group resulted in the highest viability of the PC 12 cells among the 3 dose groups(P＜0.05).Compared with the normal control group,lactacystin exposure significantly increased the number of alpha-synuclein-positive cells but decreased the TH-positive cells (P＜0.05);treatments with the drug-containing sera significantly lowered alpha-synuclein-positive cells and increased TH-positive cells in the PC 12 cells with lactacystin exposure(P＜0.05).Conclusion Anchanling can improve the function of the ubiquitin-proteasome system,reduce the intracellular aggregation of alpha-synuclein,and upregulate TH expression in the PC 12 cells to promote the cell survival and offer neuronal protection effects.