Anti-oxidants do not prevent bile acid-induced cell death in rat hepatocytes

Part of this research was presented at the American Association for the Study of Liver Diseases, 59th Annual Meeting 2008, San Francisco, USA, and at the European Association for the Study of the Liver, 43rd Annual Meeting 2008, Milan, Italy.-- et al.[Background]: Bile acids, reactive oxygen species (ROS) and inflammatory cytokines are crucial regulators of cell death in acute and chronic liver diseases. The contribution of each factor to hepatocyte death, either apoptosis or necrosis, has not been clarified as yet. It has been suggested that the generation of oxidative stress by bile acids contributes to hepatocyte death during cholestasis and bile acid toxicity, although the beneficial role of ROS prevention in bile acid-mediated cell death is not fully understood. [Aim]: Study the effects of anti-oxidants in bile acid-induced cell death in vitro. [Methods]: Primary rat hepatocytes were exposed to the bile acids glycochenodeoxycholic acid (GCDCA) or taurolithocholic acid-3 sulphate in the absence or presence of ROS scavengers or anti-oxidants. Haeme oxygenase (HO)-1 mRNA levels were analysed by quantitative polymerase chain reaction. Apoptosis was quantified by acridine orange staining and caspase-3 activity assay. Necrosis was detected by Sytox green staining. Results: Anti-oxidants do not attenuate bile acid-induced cell death. Furthermore, bile acid exposure does not enhance the mRNA expression of the oxidative stress-responsive gene HO-1. The Src-kinase inhibitor, SU6656, does reduce GCDCA-induced apoptosis and necrosis. [Conclusions]: In hepatocytes, bile acid-induced toxicity is not prevented by scavengers of oxidative stress. The beneficial effects observed in patients might be because of the contribution of ROS and cytokines rather than bile acid-mediated oxidative stress. However, the use of specific Src kinase inhibitors might be a useful tool to prevent bile acid-induced injury in liver diseases.This study was supported by grants from the Dutch Digestive Foundation and the J.K. de Cock Foundation.Grants: This study was supported by grants from the Dutch Digestive Foundation and the J.K. de Cock Foundation.Peer Reviewe

Anti-oxidants do not prevent bile acid-induced cell death in rat hepatocytes

BACKGROUND: Bile acids, reactive oxygen species (ROS) and inflammatory cytokines are crucial regulators of cell death in acute and chronic liver diseases. The contribution of each factor to hepatocyte death, either apoptosis or necrosis, has not been clarified as yet. It has been suggested that the generation of oxidative stress by bile acids contributes to hepatocyte death during cholestasis and bile acid toxicity, although the beneficial role of ROS prevention in bile acid-mediated cell death is not fully understood. AIM: Study the effects of anti-oxidants in bile acid-induced cell death in vitro. METHODS: Primary rat hepatocytes were exposed to the bile acids glycochenodeoxycholic acid (GCDCA) or taurolithocholic acid-3 sulphate in the absence or presence of ROS scavengers or anti-oxidants. Haeme oxygenase (HO)-1 mRNA levels were analysed by quantitative polymerase chain reaction. Apoptosis was quantified by acridine orange staining and caspase-3 activity assay. Necrosis was detected by Sytox green staining. RESULTS: Anti-oxidants do not attenuate bile acid-induced cell death. Furthermore, bile acid exposure does not enhance the mRNA expression of the oxidative stress-responsive gene HO-1. The Src-kinase inhibitor, SU6656, does reduce GCDCA-induced apoptosis and necrosis. CONCLUSIONS: In hepatocytes, bile acid-induced toxicity is not prevented by scavengers of oxidative stress. The beneficial effects observed in patients might be because of the contribution of ROS and cytokines rather than bile acid-mediated oxidative stress. However, the use of specific Src kinase inhibitors might be a useful tool to prevent bile acid-induced injury in liver diseases