Objective: To investigate the inhibitory effects of Curcumin on Aβ generation in vitro and explore its potential mechanisms involing BACE1 and PPARγ.Methods: Plasmids APPswe and BACE1-mychis were transiently co-transfected into SHSY5Y cells by LipofectaminTM2000

then treated with Curcumin at 0(control Group)

1.25

5.0

20.0 μmol/L for 24 hr

or with Curcumin at 5 μmol/L for 0

12

24 and 48 hrs for the time course assay.RT-PCR was performed to measure the endogenous levels of BACE1 mRNA and PPARγ.Western blot were used to detect the protein expression of BACE1 and PPARγ.The major cleavage product——Aβ40 and Aβ42 was detected by β-amyloid 1-40 or 42 Colorimetric ELISA assay.Results: The mRNA level and protein level of BACE1 were decreased obviously in a dose-and time-dependent manner after treated with Curcumin in the cell line(P<0.05).Conversely

the expression of PPARγ increased at both mRNA and protein levels after treated with curcumin

also they were in a dose-and time-pendent manner(P<0.05).ELISA results showed that the generation of Aβ40 and Aβ42 reduced significantly

also in a dose-and time-dependent manner(P<0.05).Conclusion: Aβ generation could be obviously inhibited by Curcumin in co-transfected SHSY5Y cell lines and that the protective mechanism of Curcumin in AD involves activation of PPARγ and decreasing BACE1 at gene and protein levels.