Copper zinc superoxide dismutase (CuZnSOD) activity was not altered by treatment with chemotherapeutics [paclitaxel (Pac), oxaliplatin (Ox), and bortezomib (Bort)] or Mn(III) 5,10,15,20-tetrakis(N-n-hexylpyridinium-2-yl)porphyrin (MnTE-2-PyP5+). Treatment with the chemotherapeutics paclitaxel (A), oxaliplatin (B), or bortezomib (C) either alone (black bars) or in combination with MnTE-2-PyP5+ (gray bars) had no effect on the activity of CuZnSOD compared with vehicle treatment (open bars). Results are expressed as mean ± SD, n = 6 and analyzed by one-way analysis of variance with Dunnett’s post-hoc comparisons. n.s. = not significant.