Figure 2.

Metformin decreases live cells and induces cell death in vitro, which can be prevented by the addition of exogenous NAD+. MCF7 cells were pretreated with NAD+ (1 mM) for 3 days and subsequently treated with or without metformin (8 mM) for 2 days. Dead and live cell numbers were obtained using the trypan blue exclusion assay. (* and # indicate significant difference between groups with p < 0.05.).