Oxidative stress and changes in liver antioxidant enzymes induced by experimental dicroceliosis in hamsters

The purpose of our study was to assess the effects of experimental dicrocel iosis on the antioxidant defense capability of the liver in hamsters. Studi es were carried out at 80 and 120 days after infection with an oral dose of 40 metacercariae of Dicrocoelium dendriticum. The parasitic pathology was ascertained by the presence of fluke eggs in feces, increased serum ALT and AST activities. and histological findings. The concentration of thiobarbit uric acid-reactive substances (TBARS) and the ratio of oxidized to reduced glutathione (GSSG/GSH), measured as markers of oxidative stress, were signi ficantly increased [TBARS: + 40% and + 84% at 80 and 120 days postinfection (p.i.), respectively, GSSG/GSH: + 200% and + 117%]. Dicroceliosis increase d Se-dependent glutathione peroxidase (GPx) activity in both cytosol (+ 24% and + 46%) and mitochondria (+73% and +41%). Superoxide dismutase activity was significantly reduced in cytosol (-19% and -38%) and mitochondria (-20 % and -39%). No significant change was found in the activity of Se-independ ent GPx or catalase. The ratio of glutathione peroxidase/glutathione reduct ase at 80 and 120 days p.i. was increased by 25% and 63%, respectively. Gam maglutamyl cysteinyl synthetase activity was increased by 27% and 20%, resp ectively. Our data indicate that although dicroceliosis courses with activa tion of antioxidant enzymes and glutathione synthesis, inefficient scavengi ng of reactive oxygen species takes place, resulting in oxidative liver dam age.