Figure 1.

Cela sensitizes TRAIL-initiated apoptosis in A549 cells. A549 cells were treated with different dose of cela (1, 2 and 4 µM) for 12 h and then exposed to TRAIL (200 ng/ml) for 2 h. (A) The morphology of the cells was evaluated by interference light microscopy (magnification, ×100). (B) Cellular viability was assessed with crystal violet staining. (C) Quantification data for the crystal violet staining cell viability. (D) Cellular viability was evaluated with trypan blue dye exclusion assays. *P<0.05 and **P<0.01 vs. TRAIL untreated group and only TRAIL treatment group. Cela, celastrol; TRAIL, tumor necrosis factor-related apoptosis-inducing ligand.