Objective: To discuss the effect of curcumin on the apoptosis of adrenal pheochromocytoma (PC12) cells induced by β-amyloid protein 25-35 (Aβ25-35) and the expression of cytochrome C (Cyt C) in mtochondria of rats

in order to analyze the mitochondrial mechanisms of anti-apoptosis. Method: Aβ25-35 was used to treat PC12 cells

and the cellular model of Alzheimer's disease (AD) was established. The PC12 cells were treated with curcumin at concentrations of 0 (blank control group)

1.25

2.5

5

10

20

40 μmol·L-1

respectively. The survival rate was measured by 3-(4

5-dimethyl-2-thiazolyl)-2

5-diphenyl-2-H-tetrazolium bromide(MTT). The PC12 cells were randomly divided into the blank control group

the model group

the low-dose (10 μmol·L-1) curcumin group and the high-dose (20 μmol·L-1) curcumin group. The effect of curcumin on the apoptosis

the changes in mitochondrial membrane potential (Δψm)

the distribution of Cyt C and the expression of Cyt C in mitochondria were evaluated by Annexin V-FITC/PI flow cytometry

JC-1 staining assay

immunofluorescence analysis and Western blot analysis

respectively. Result: Compared with the blank control group

the survival rate of PC12 cells was decreased significantly

and the apoptosis rate was increased in model group (P<0.01). Compared with the model group

curcumin significantly increased the cell viability and decreased the apoptosis rate (P<0.01). Compared with the blank control group

Δψm decreased significantly

the release of mitochondrial Cyt C to cytosol increase

and the expression of Cyt C in mitochondria down-regulated in model group (P<0.01). Compared with the model group

curcumin significantly increased Δψm

inhibited the release of mitochondrial Cyt C to cytosol and Up-regulated the expression of Cyt C in the mitochondria (P<0.05

P<0.01). Conclusion: Curcumin can inhibit the apoptosis of PC12 induced by Aβ25-35 by suppressing mitochondrial apoptosis pathway.