Effects of bafilomycin A1 on Res-induced death of U251 cells. U251 cells were pretreated with various doses of bafilomycin A1 1 h before Res (150 μM). Cell viability was evaluated by MTT assay 24 and 48 h later. Data are presented as means ± SD (n = 3). *, p < 0.05 compared to control group; #, p < 0.05 compared to Res alone group.