Panel (A) shows the effects of doxorubicin on cell viability of Cos-7 cells following 24 h exposure. Panel (B) shows the effects of DOX (7 µM) on the leakage of LDH from Cos-7 cells after 24 h of exposure. Treatment with 1% triton was used as a positive control to induce complete leakage of LDH from cells. Panel (C) shows the effects of 4 h pre-treatment with necrostatin-1 (10 µM) upon cell viability of Cos-7 cells then exposed to DOX (7 µM) for 24 h. Panel (D) shows the effects of 4 h pre-treatment with caspase 3 inhibitor (50 µM) upon cell viability of Cos-7 cells that were then exposed to DOX (7 µM) for 24 h. Panel (E) shows the effects of 4 h pre-treatment with caspase 9 inhibitor (50 µM) upon cell viability of Cos-7 cells that were then exposed to Dox (7 µM) for 24 h. All data are presented as the mean ± SD of four replicates. Statistical analysis via two-tailed Student T-test was performed in comparing cell viability levels in DOX-treated cells in the presence and absence of caspase inhibitors. Probability values *P<0.05, **P<0.01.