Figure 1 (A) Viabilities of cultured neurons were determined by MTT. The line chart demonstrates the cell viabilities of neurons incubated with Bf at concentrations of 0, 70, 140, and 280 nmol/L. (B) TUNEL assay was used to evaluate apoptosis. The TUNEL-positive neurons were tagged with green fluorescence and are demonstrated in the captured fluorescent images. Columns indicate the apoptotic rate of neurons incubated with Bf at concentrations of 0, 70, 140, and 280 nmol/L. [n=10; a difference was significant when compared with neurons incubated with control; b difference was significant when compared with neurons incubated with Bf at 70 nmol/L; c difference was significant when compared with neurons incubated with Bf at 140 nmol/L].