Objective       To determine the effect of curcumin on the expression of apolipoprotein E (ApoE) in murine neuroblastoma Neuro2a (N2a) cells.       Methods       MTT assay was used to detect the effect of curcumin at the doses of 2.5

5

10

20 and 40 μmol/L on the viability of N2a/APP695 cells

a cellular model of Alzheimer’s disease. After the N2a/APP695 cells then were treated w

ith curcumin at 5

10 and 20 μmol/L for 48 h

the mRNA levels of ApoE and low density lipoprotein receptor (LDLR) in N2a cells were evaluated by RT-PCR

and their protein levels were determined by Western blotting. The cellular content of ApoE was measured by immunocytochemical staining.       Results       Curcumin treatment resulted in significant increase in the cell viability

especially at the dose of 20 μmol/L (

P

0.05). Compared to normal cells

the mRNA and protein expression of ApoE were increased in N2a/APP695 cells

the LDLR expression

instead

were decreased (

P

0.01). Treatment with curcumin distinctly decreased ApoE expression and increased LDLR production in a does-dependent manner (

P

0.05). Further more

ApoE was mainly located in the cytoplasm  and cell membrane

and the number of ApoE positive cells were increased and hyper-chromatic compared to normal cells. but the number of ApoE positive cells were decreased and the color grew pallid after the treatment of curcumin (

P

0.01).       Conclusion       Curcumin inhibits the ApoE production in N2a/APP695 cells via facilitating the expression of LDLR.