Fig. 2.

Effects of propolis on neurite outgrowth in differentiating SH-SY5Y neuroblastoma cells. (A) The cells were induced to differentiate for 48 hr with RA (10 μM) in the presence or absence of propolis (0.3~3 μg/mL). Cells were fixed in 4% paraformaldehyde and stained with Coomassie Brilliant Blue (CBB). Shown are images of typical fields of cells viewed by inverted light microscope. (B) Neurite outgrowth was quantified by counting the number of cells exhibiting neurites that were two times longer than the cell body diameter in length. The proportion of cells with neurites was expressed as a percentage of the total number of cells. Approximately 300 cells were counted in each sample. The data are expressed as the mean ± standard error of four independent experiments. *p<0.05 when compared to RA-treated cells. Scale bar = 100 μm.