Abstract: Objective To investigate the effects of curcumin on the proliferation, migration, invasion, and apoptosis of pheochromocytomacell line PC12. Methods PC12 cells were incubated with different concentrations of curcumin. Cell proliferation was assessed using the CCK-8 assay to determine the IC₅₀. The scratch assay was used to evaluate cell migration and Transwell chambers were employed to assess cell invasiveness. Flow cytometry was used to analyze apoptosis. qPCR was conducted to measure the mRNA expression of pro-apoptotic (Bax) and anti- apoptotic (Bcl-2) genes, and Western blot was performed to detect Bax and Bcl-2 protein expressions. Results Curcumin(10-80 μmol/L) inhibited PC12 cell proliferation in a concentration-dependent manner, with an IC₅₀ as 29 μmol/L. Curcumin also suppressed PC12 cell migration in a concentration-dependent mode; the migration rate decreased from 66% in the control group down to 51%, 5%, and 0.5% in the 10, 20, and 30 μmol/L curcumin groups, respectively. Curcumin at concentrations of 20-30 μmol/L significantly reduced PC12 cell invasiveness(P＜0.000 1). Moreover, curcumin significantly promoted PC12 cell apoptosis; the percentage of apoptotic cells increased by 2.25%, 18.53%, and 26.89% in the 10, 20, and 30 μmol/L curcumin groups as compared to those of control group, respectively. Curcumin treatment resulted in a significant up-regulation of Bax mRNA and protein expression, and a significant down-regulation of Bcl-2 mRNA and protein expression(P＜0.05). Conclusions Curcumin may significantly inhibit the proliferation, migration, and invasion of PC12 cells and arouse cell apoptosis. Its pro-apoptotic effect may be associated with alterations in the expression of Bax and Bcl-2 genes.

Key words: curcumin, PC12 cell, apoptosis, invasion, migration