ABSTRACT
OBJECTIVE To investigate the protective effect of curcumin on Aβ1-42 damaged cells. METHODS SH-SY5Y cells were cultured with Aβ1-4210μmol · L-1 in the absence or presence of curcumin 1, 5 or 10 μmol · L-1. Cell viability was assayed by MTT. Cell membrane damage was detected by the concentration of lactate dehydrogenase (LDH) in culture medium. Cell apoptosis was measured by flow cytometry with Annexin Ⅴ-FITC/PI staining. Mitochondrial membrane potential was characterized by fluorescence of JC-1 dye. Enzymatic activity of caspases-9 and-3 was measured by colorimetric assay. Protein expression of caspase-3 was detected by Western blotting. RESULTS Compared with vehicle control, the cell viability, concentration of LDH and both early and late apoptosis in Aβ1-4210 μmol · L-1 damaged group were decreased(P<0.01). However, the cell viability, release of LDH and both early and late apoptosis in curcumin group were promoted compared with that in Aβ1-4210μmol·L-1 damaged group. Curcumin inhibited Aβ1-42-induced depolarization of mitochondrial membrane potential(P<0.01), and attenuated Aβ1-42-induced activation of both caspases9 and caspases3 in a concentration-dependent manner, respectively(r=0.990, P<0.01; r=0.996, P<0.01). There were no significant differences in the above detected indexes between curcumin 10 μmol · L-1 group and vehicle control group. CONCLUSION Curcumin inhibits Aβ1-42-induced cell damage and apoptosis by promoting mitochondrial membrane potential and depressing the activation of caspases.