Disulfiram inhibits TNF-alpha-induced cell death

Disulfiram, a clinically employed alcohol deterrent, was recently discovered to inhibit caspase-3 and DNA fragmentation. Using LLC-PK1 cells and murine liver as models, we examined if the drug inhibited TNF-alpha-induced cell death. Disulfiram produced dose-dependent inhibition of TNF-alpha-induced cell death as well as caspase-3-like activity, Disulfiram retained 80% of its effect when added 4 h after TNF-alpha. Disulfiram protected the cells from cytokine-induced death for at least 6 days. The cells rescued by the drug preserved the ability to proliferate. The cells died spontaneously after exposure to TNF-alpha for just 70 min. Co-administration of 15 mu M disulfiram and TNF-alpha for 70 min prior to their removal abolished TNF-alpha-induced killing, and this was associated with restoration of mitochondrial membrane potential and suppression of reactive oxygen species. Treatment of mice with TNF-alpha and D-galactosamine for 5 h markedly increased hepatic DNA fragmentation and caspase-3-like activity. Disulfiram at 0.6 mmol/kg abolished these effects. We conclude that disulfiram is a potent inhibitor of TNF-alpha-induced cell death in vitro. The underlying mechanisms include stabilization of mitochondrial membrane potential, suppression of reactive oxygen species, and inhibition of caspase-3-like activity. We further conclude that disulfiram inhibits DNA fragmentation in vivo in association with the blockade of caspase-3-like activity.