Abstract: Objective To investigate the effects of Epimedium flavanoids (EF) on β-amyloid (Aβ) in APP695 cDNA-transfected human neuroblastoma cell line SH-SY5Y cells.Methods The immunoprecipitation plus Western blotting and radioimmunoassay were used to detect Aβ concentration in the supernatant of cell culture and cell disruption fluid. The activity of β-secretase (BACE1) was measured by detecting the fluorescence value of substrate cut by BACE1.Results Incubation of EF 2.5～25 g/ml with APP695 cDNA-transfected SH-SY5Y cells for 24 h significantly decreased Aβ content in the supernatant of cell culture (P<0.05, P<0.01). EF 50 g/ml inhibited the activity of BACE1 by 95.0% in vitro.Conclusion EF can decrease Aβ production and secretion of APP695 cDNA-transfected nerve cells.

Key words: Epimedium flavanoids, β-amyloid, β-secretase, Alzheimer disease