Nifurtimox (BAY-A-2502) is an antiprotozoal agent (IC50s = 9.91, 12.28, and 10.44 μM against Taluahuén, LQ, and Brener strains of T. cruzi- epimastigotes, respectively).

T. cruzi Brener strains:10.44 μM, LQ:12.28μM, Taluahuén:9.91μM

Nifurtimox can produce anion radicals and interfere with oxygen metabolism [1]. On the neuroblastoma cell lines LA-N-1, IMR-32, LS and SK-N-SH, the treatment of nifurtimox shows an increased production of oxidative stress, a reduced lactate dehydrogenase enzyme activity and reduced lactate production. Furthermore, nifurtimox leads to reduced mRNA and protein levels of the proto-oncogene protein N-Myc [2].

To assess the cell viability after incubation with nifurtimox at different concentrations (10 μg/mL up to 50 μg/mL or 34.8 μM to 174 μM, respectively in the supernatant growth medium) or the vehicle control with according concentrations, all neuroblastoma cell lines were subjected to an MTS assay. Stock solutions of MTS were made at 480 μM in sterile filtered deionized water and stored at ?20°C. Cells were grown to approximately 50% confluency, treated with nifurtimox, and incubated for 1 h with fresh media containing 12 μM MTS. The supernatant was subsequently removed and the cells were lysed with DMSO containing 10% (w/v) sodium dodecyl sulfate (SDS) and 1% (v/v) glacial acetic acid (Carl Roth, #3738). Purple formazan contents of each cell lysate were photometrically analyzed in triplicates at 570 nm (630 nm reference wavelength) in 96 microtiter plates [2].