Pleiotropic Effects of Biguanides on Mitochondrial Reactive Oxygen Species Production

Figure 5

Effect of biguanides on reactive oxygen species (ROS) production compared to typical inhibitors. The rate of H₂O₂ generation was estimated by Amplex red assay. H₂O₂ production with (a) 10 mM pyruvate and 2 mM malate (P + M) with or without 1 μM rotenone (ROT), (b) 10 mM succinate (saturating SUC) with or without 0.5 μM atpenin A5 (AA5) or 1 μM rotenone, (c) 0.4 mM succinate (physiological SUC) with or without 0.5 μM atpenin A5, and (d) 10 mM glycerophosphate (GP) with or without 100 μM iGP-1 (iGP) were indicated; BAT mitochondria were coupled with 1 mM guanosine diphosphate (GDP). (e) Titration of H₂O₂ production by biguanides metformin (MF, 0–200 mM) or (f) phenformin (PF, 0–60 mM) using the same substrate concentrations as in respective experiments in (a–d). Each point is the mean ± SEM of at least three independent measurements.

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