Protective effect of antioxidative vitamins against lipid eroxidation in liver ischemia and reperfusion

Abstract

Ischemia and reperfusion (I/R) leads to oxidative stress with free radical formation. With respect to liver surgery and transplantation this can lead to deleterious clinical effects. Protection of the liver against I/R injury is of major concern. Thus, in this study, we examined the effect of an antioxidant vitamin solution (vitamin E, C and ß-carotene) on warm I/R injury. Twelve pigs of the German landrace (7 animals in the vitamin group and 5 untreated controls) were examined in this animal model. Twenty-four hours before laparotomy, the vitamin group was initiated with a single intravenous infusion of the vitamin cocktail. The duration of complete warm ischemia of the liver was 4 hours. Serum liver enzyme levels (AST and ALT) and with thiobarbituric acid reacting substances (TBARS) in liver tissue were measured. Furthermore, immunohistochemical staining of oxidative products (oxidized proteins and 4-hydroxy-nonenal = 4-HNE) in liver tissue was made. The maximum accumulation of oxidized proteins was seen six days postoperatively in the controls whereas in the vitamin group only small amounts were seen. 4-HNE showed a marked accumulation in the controls but was almost not detectable in the vitamin group. TBARS were lower in the vitamin group compared to controls. Although the emulsifier necessary for the vitamin solution leads to increased liver enzyme levels in the vitamin group, the values returned to normal more rapidly. Antioxidant vitamins are able to improve warm I/R liver injury. Oxidative stress is directly verifiable at the tissue level. Future animal experiments as well as clinical trials are necessary to explore the optimization of the combination of antioxidative vitamins for the maximum protection from I/R injury.