Objective: To investigate the expression changes of p53 mRNA and its related genes in 1-methyl-4-phenylpyridinium iodide(MPP+)-induced SH-SY5Y cells and observe the protective effects of puerarin against the cell death. Method: SH-SY5Y cells were incubated to 70% confluence

the medium containing 50

100

150 μmol·L-1 puerarin was added to SH-SY5Y cells

at 3 h after drug application 1 mmol·L-1 MPP+ was added to culture. The viability of MPP+-induced SH-SY5Y cells under different doses of puerarin was assayed by 3-(4

5-dimethylthiazol-2-yl)-2

5-diphenyltetrazolium bromide(MTT)at 48 h. The apoptosis rates were detected by flow cytometry with Annexin-V/PI fluorescence staining. The expression of p53 mRNA and its related genes was assayed by real-time quantitative reverse transcription-PCR(RT-PCR)at 24 h. Result: The puerarinpretreatment could apparently increase the viability and inhibit the early apoptosis of the MPP+-induced SH-SY5Y cells in the experiment(P<0.05). Annexin-V/PI fluorescence staining results showed that puerarin could reduce the apoptosis rate of MPP+-induced SH-SY5Y cells. Real-time PCR results showed that the MPP+ could increase the expression of p53 mRNA

but the expression of p53

p21

Bax

Caspase-3 mRNA was down-regulated in puerarin pretreatment groups compared with the MPP+ group

and the expression of MDM2 and Bcl-2 mRNA was up-regulated simultaneously. Conclusion: The expression of p53 mRNA in SH-SY5Y cells can increase by MPP+ and puerarin can regulate the p53 and its related genes and play a protective role against the death of MPP+-induced SH-SY5Y cells.