[Role of oxidative stress in non-alcoholic steatohepatitis]

Oxidative stress plays an important role in the pathogenesis of non-alcoholic steatohepatitis (NASH). Reactive oxygen species (ROS) would derive from mitochondria, cytochrome P-450 2E1, peroxisome, and iron overload in the liver with steatosis. These excessive ROS is considered to cause simple steatosis to progress to NASH. On the other hand, oxidative stress exacerbates insulin sensitivity in hepatocytes, while hepatic steatosis causes oxidative stress. Thus, oxidative stress and insulin resistance might be interactive in NASH. Actually, we have found that the grade of steatosis correlates with serum thioredoxin level, a marker of oxidative stress, in NASH patients. Therefore, we propose that the feedback loop of oxidative stress, insulin resistance, and steatosis would play a significant role in the development of NASH.