Effect of sesquiterpene lactones on antioxidant enzymes and some drug-metabolizing enzymes in rat liver and kidney

Previously we have reported that several sesquiterpene lactones isolated fr om Helenium aromaticum and Telekia speciosa showed pro-oxidative properties and caused glutathione level depletion in rat liver in vivo. In the presen t study we examined the in vivo effect of these lactones on antioxidant enz yme systems and some drug metabolizing enzymes in the liver and the kidney of rats. We found that the majority of the compounds increased the hepatic activity of glutathione peroxidase (GPx), glutathione reductase (GR), and c atalase (CAT), but superoxide dismutase (SOD) activity was distinctly lower ed by five lactones. A few of the compounds tested caused a decrease in the hepatic cytochrome P450 content and reduced the activity of NADPH-cytochro me P450 reductase, aminopyrine demethylase, aniline hydroxylase and glutath ione-S-transferase. Results for the kidney showed fewer changes in activiti es of both classes of enzymes when compared to the liver. Not all lactones affected the enzymes under test, the most active were: linifolin, helenalin , mexicanin I and telekin. 6 alpha-Hydroxy-2,3-dihydroaromaticin behaved di fferently towards monooxygenases since it induced the activity of aminopyri ne demethylase and aniline hydroxylase.