Effects of baicalein and baicalin on rotenone-induced cell death in SH-SY5Y cells. Cells were incubated with increasing concentrations of rotenone (A), baicalein and baicalin (B) respectively for 24 hours in serum-free medium (n = 6, *P < 0.01 versus control). Cells were pretreated with baicalein (C) or baicalin (D) for 1 hour and then cotreated with 20 μM rotenone for 24 hours in serum-free medium (n = 6, #P < 0.01 versus control, *P < 0.01 versus rotenone treatment). E: The morphological change was visualized by phase-contrast imaging. Scale bar: 50 μm.