['Hepatitis C virus (HCV) core protein has been shown to inhibit mitochondrial electron transport and to increase reactive oxygen species (ROS) in vitro and in vivo. The aim of this study was to investigate whether inhibiting HCV replication could restore the mitochondrial redox state and electron transport activity.', 'We measured ROS, mitochondrial reduced glutathione content, and mitochondrial complex I, II, III and IV activities and protein expression in full genomic HCV replicon cells and cured cells that had been prepared by eliminating HCV RNA from replicon cells by interferon (IFN)-alpha treatment.', 'Cured cells had significantly lower ROS production and greater mitochondrial glutathione content than replicon cells. Complete inhibition of HCV replication by IFN-alpha restored complex I and IV activities by 20-30% (P<0.01) and complex I expression (P<0.05). Treatment with fluvastatin, one of the 3-hydroxy-3-methylglutaryl co-enzyme A reductase inhibitors, which is known to have anti-HCV activity, partially inhibited core protein expression and restored complex I activity in full genomic HCV replicon cells to a lesser degree (P<0.05).'] Is mitochondrial electron transport inhibition in full genomic hepatitis C virus replicon cells restored by reducing viral replication?