4-Nitrobenzylidene malononitrile reduces apoptosis-mediated liver injury in mice.

Abstract Background : Apoptosis plays a role in experimental and clinically related liver damage. Inhibitors of tyrosine kinases were shown to modulate apoptosis induced by different agents in various cell types. Aims : Investigation of the effect of 4-nitrobenzylidene malononitrile (belonging to the tyrphostins family which are selective inhibitors of protein tyrosine kinases) on apoptosis-mediated acute liver injury. Methods : Two murine experimental models exhibiting apoptosis-mediated liver injury were used: (1) mice treated with tumor necrosis factor- α and d-galactosamine; and (2) mice treated with anti-Fas antibody. Liver injury was assessed by serum levels of transaminases and by microscopic analysis. Apoptosis was assessed by labeling of apoptotic cells in the liver by the TUNEL assay and by determination of caspase-3 activity. Results : Pretreatment of mice with 4-nitrobenzylidene malononitrile reduced tumor necrosis factor- α /d-galactosamine-induced hepatotoxicity. TUNEL positive cells in sections from livers treated with vehicle (control), 4-nitrobenzylidene malononitrile, tumor necrosis factor- α /d-galactosamine and tumor necrosis factor- α /d-galactosamine and 4-nitrobenzylidene malononitrile, were >0.2, >0.2, 49±2.3 and 4±0.2 per mm 2 , respectively. 4-Nitrobenzylidene malononitrile also reduced hepatotoxicity induced by anti-Fas antibody. Caspase-3 activation induced by either tumor necrosis factor- α /d-glactosamine or by anti-Fas treatment, was reduced by pretreatment with N -nitrobenzylidene malononitrile Conclusions: The findings may provide a base for development of a new therapeutic modality to reduce apoptosis-mediated liver damage.