[Investigation of redox homeostasis of liver in experimental and human studies]

Great importance has been attributed to antioxidants in the treatment of conditions associated with oxidative stress for many years. At the same time the antioxidants can exert prooxidant activity. Combined antioxidant treatment is more favourable compared with monotherapy, because antioxidants have scavenger-, compartment- and tissue-specificity and they regenerate each other directly, too. Drugs of chronic liver diseases should be considered because of the role of liver in biotransformation. Our aim was to study the redox status of liver and investigate the effects of natural antioxidants (vegetable lyophilizates, silymarin, metadoxine) on liver redox status. Besides of clinical diagnosis, biochemical, analytical, histological methods were used to assess the free radical-antioxidant balance on the whole. Our in vitro methodological system is suitable for screening natural compounds for primary and secondary antioxidant property as well as membrane-stabilizing activity. A shift in free radical-antioxidant balance was proved in short-term extrahepatic cholestasis, antioxidant-type choleretic compounds can be investigated in this animal model. In human experiments redox status was investigated in the Gilbert's disease and in the most frequent chronic liver disorder in Hungary, in alcoholic liver disease. The improvement of non-enzymatic antioxidant defence system was found in Gilbert's disease without the alteration of free radical-antioxidant balance. Our results proved the role of free radical reactions in alcoholic liver disease and underlined the greater women vulnerability to alcohol toxicity. The chemiluminometric measurements in erythrocytes is suitable for the estimation of progression of alcoholic liver disease and of efficacy of antioxidant therapy.