Abstract:

Objective    To explore the protective effect of curcumin (Cur) on apoptosis of PC12 cells induced by dopamine (DA) oxidative stress. Methods    Using DA to induce PC12 cell damage, the model of oxidative stress-induced neuron damage was established. Proliferation of PC12 cells was observed by 3-［4 ,5dimethylthiazolyl ］-2 ,5diphenyltetrazolium bromide (MTT) assay. Morphology of the nucleus was observed by Hoechst staining. Apoptosis of PC12 cells was detected by propidium iodide(PI) staining flow cytometry (FCM). The mitochondrial membrane potential(△Ψm) was determined by Rh123 staining flow cytometry. Results    ① DA damaged PC12 cells in a concentration-dependent manner after application of DA (50-800μmol/L) for 24h, and MTT assay showed that Cur （10-40μmol/L） had no toxic effect on PC12 cells . ② Cur reduced the toxic effect induced by DA on PC12 cells in a concentration-dependent manner.  ③ Cur reducing the DA-induced toxic effect on PC12 cells was confirmed by cellular morphologic experiments. ④ PI staining FCM showed that Cur inhibited cellular apoptosis induced by DA and this effect was also confirmed by Hoechst staining. ⑤ The level of △Ψm was significantly decreased in PC12 cells after 100 and 200μmol/L DA treatment for 24h, which was significantly ameliorated by Cur (20 and 40μmol/L) treatment. Conclusion     Cur has a protective effect on PC12 cell damage induced by DA oxidative stress and this effect may be ascribed to the amelioration of the decreasing  level of △Ψm.

Key words: Curcumin; Dopamine; Oxidative stress; PC12 cells; Membrane potentials