Effect of TMPD and ascorbate (ASC) on apoptosis induced by MTX.

<p>Cells were incubated with TMPD (A) or ASC (B) either alone or in combination with MTX at the indicated concentrations for 18 h. TMPD or ascorbate were added 12 h before MTX. Changes in mitochondrial membrane potential were determined using the Rhodamine 123/Propidium Iodide assay. Apoptosis is expressed in fold change compared to untreated cells. Results represent the mean ± SE of 3 different experiments. Staurosporine (STP) was used as a positive control. ^**<i>p</i><0.01, ***<i>p</i><0.001.