Metformin decreases ATP levels in medium containing low glucose (2.5 mM).

<p>MDAMB231 (<b>A</b>) and (<b>B</b>) MCF7 cells were treated with metformin (8 mM) in either 25 mM glucose or 2.5 mM glucose for one day and ATP levels were measured and fold change of ATP compared with control was plotted. <b>C.</b> ATP measurements in PA-1 cells after 12 hours with or without metformin. This time point was chosen because of the rapid rate of PA-1 growth under control culture conditions. Data were presented as mean ± standard deviation. All metformin treated groups in medium containing low glucose (2.5 mM) were significantly different from their control groups. *Indicates significant difference between groups.