Essential oils of Coriandrum sativum L. and Carum carvi L. fruits were analyzed by gas chromatography-mass spectrometry and assayed for their in vitro and in vivo antioxidant activity and hepatoprotective effect against carbon tetrachloride (CCl(4)) damage. The in vitro antioxidant activity was evaluated as a free radical scavenging capacity (RSC), measured as scavenging activity of the essential oils on 2,2-diphenyl-1-picrylhydrazyl (DPPH(*)) and OH radicals and effects on lipid peroxidation (LP) in two systems of induction. Some liver biochemical parameters were determined in animals pretreated with essential oils and later intoxicated with CCl(4) to assess in vivo hepatoprotective effect. Tested essential oils were able to reduce the stable DPPH(*) in a dose-dependent manner and to neutralize H(2)O(2), reaching 50% neutralization with IC(50) values of <2.5 microL/mL for Carvi aetheroleum and 4.05 microL/mL for Coriandri aetheroleum . Caraway essential oil strongly inhibited LP in both systems of induction, whereas coriander essential oil exhibited prooxidant activity. In vivo investigation conferred leak of antioxidative capacity of coriander essential oil, whereas the essential oil of caraway appeared promising for safe use in folk medicine and the pharmaceutical and food industries.