Compound C does not increase hydrogen peroxide production from both forward and reverse electron flux of complex I. 0.1 mg/ml of isolated mouse liver mitochondria were incubated in reaction buffer with either 5 mM glutamate/5 mM malate or 10 mM succinate as respiratory substrates or inhibitors (5 μM rotenone and 20 μM Compound C) at 37°C. Hydrogen peroxide production was assessed by homovanillic acid/horseradish peroxidase. Mitochondria, substrates and inhibitors were sequentially added as shown in the figure. The results shown are representative of 2 independent experiments.