PTX + MG132 induces loss of the mitochondrial membrane potential (ΔΨm). U937 cells were cultured and treated with 8 mM PTX, 1 μM MG132, or PTX + MG132. After 24 hours, the cells were harvested and the ΔΨm was assessment by flow cytometry using DIOC6 staining. Protonophore carbonyl cyanide m-chlorophenylhydrazone (CCCP) was used as a positive control. The results represent mean ± standard deviation of three independent experiments performed in triplicate. Statistical analysis Mann-Whitney U test. * p <0.05 all groups vs untreated control group (UCG); ● p <0.05 PTX + MG132 vs all groups.