Figure 5

Box-and-whiskers plot showing the logarithmic transform of the ratio between the IVIS fluorescence at the end and at the beginning of the treatment in the three experimental groups: control, gel (treatment with metformin-containing gel 100 mg/ml) and sol (treatment with metformin-aqueous solution 100 mg/ml). Seven animals per group were s.c. injected with MDA-MB-231 cells that were allowed to grow till a visible tumor developed (7 days). Then, the volume of the tumors was evaluated by IVIS and the mice randomly divided in the three experimental groups, in a way that the chemiluminescence values were similar among groups. Then mice were treated every other day for 15 days with 100 mg of metformin formulations. At the end of the treatment, a second IVIS measurement was performed. The gel formulation caused a reduced tumor growth that was significantly different according to post-hoc tests (Tukey’s, Bonferroni, Fisher’s LSD, Scheffé, *p < 0.05) from both control and solution treatment. In each box, the central line marks the median of the data; the box edges indicate the first and third quartiles. The whiskers show the range of values falling within the inner fences (i.e. interquartile range multiplied by 1.5)⁵⁶.