Etoposide prevents apoptosis in mouse liver with D-galactosamine/lipopolysaccharide-induced fulminant hepatic failure resulting in reduction of lethality

D-Galactosamine (GalN)/lipopolysaccharide (LPS)-induced liver injury is an experimental model of fulminant hepatic failure in which tumor necrosis fac tor alpha (TNF-alpha) plays a pivotal role. We examined the effects of etop oside on GalN/ LPS-induced fulminant hepatic failure, Mice were given an in traperitoneal dose of GalN (800 mug/g body weight)/LPS (100 ng/g body weigh t) with and without intraperitoneal etoposide (10 mug/g body weight) treatm ent. Liver injury was assessed biochemically and histologically. TNF-cu lev els in the serum, and apoptosis of hepatocytes and CPP32/caspase-3 in the l iver, were determined. GalN/LPS treatment caused lethal liver injury in 87% of animals (13 of 15), The effect was associated with significant increase s in TNF-alpha and alanine transaminase (ALT) levels in serum, the number o f apoptotic hepatocytes, CPP32/caspase-3 activity, and TNF receptor 1 (TNFR 1) mRNA expression in the liver, Etoposide (10 mug/g body weight) was given 3 times (at 50, 26, and 4 hours before GalN/LPS administration). Treatment of GalN/LPS-treated mice with etoposide reduced apoptosis of hepatocytes, resulting in reduction of lethality (13% [2 of 15]), while another topoisom erase II inhibitor, IRCF-193, showed no significant effect. The antilethal effect of etoposide was also confirmed in GalN/TNF-alpha -induced fulminant hepatic failure. Etoposide treatment reduced CPP32/caspase-3 activity in t he liver, although it did not alter the serum TNF-alpha levels or hepatic T NFR1 mRNA expressions. In addition, etoposide treatment enhanced the mRNA a nd protein expression of Bcl-xL, an antiapoptotic molecule in the liver. Th e present findings suggest that etoposide prevents endotoxin-induced lethal liver injury by up-regulation of Bcl-xL, and that etoposide could be usefu l for the treatment of TNF-alpha -mediated liver diseases.