Figure 3.

The effect of metformin on mitochondria in MDA-MB-231 cells as a function of glucose level. MDA-MB-231 cells were treated with 5 mM metformin in the RPMI medium supplemented with 5.6 mM or 0 mM glucose (Glc). The cells were treated for 48 h with daily medium change and TEM micrographs were captured. The (A) average number of mitochondria per surface area of cytoplasm and (B) mean length of mitochondria were determined. Each data point represents data from individual micrographs from two independent experiments and horizontal bars indicate mean ± SEM. ** p < 0.01 as determined by ANOVA. (C–F) Representative micrographs of the control with (C) 5.6 mM glucose, (D) 5 mM metformin 5.6 mM glucose, (E) control 0 mM glucose and (F) 5 mM metformin in 0 mM glucose at 3900× magnification. Scale bar = 1 μm.