Abstract
Oxidative stress is thought to be critical for the pathogenesis of hepatic steatosis and its progress to non-alcoholic steatohepatitis. Berberine (BBR) can improve hepatic steatosis. In this study, we investigated the role of BBR in ameliorating oxidative stress. Lipid accumulation was measured in the livers of C57BL/6 mice fed a high fat diet (HFD) or a normal diet for 8 weeks, then either received BBR or vehicle for the study duration. Nrf2 distribution was detected in male Sprague-Dawley rats' livers in vivo and in Huh7 cells in vitro. ROS generation and mitochondrial complex expression was measured in Huh7 cells. HepG2 cells were employed for the measurement of oxygen consumption rates. Our results showed that BBR reduced triglyceride accumulation in the liver of HFD-fed mice. The activation and nuclear distribution of Nrf2 was decreased in the hepatocytes of rats that received BBR treatment, while on a HFD. BBR also markedly reduced Nox2-dependent cytoplasmic ROS production and mitochondrial ROS production, which was mediated by the down-regulation of Complex I and III expression. In conclusion, BBR has a great potential to reduce the effects of oxidative stress, which likely contributes to its protective effect in inhibiting the progression of hepatic steatosis to steatohepatitis.