Fig. 4

a Effect of 2 mM metformin on the levels of the essential fatty acid, linoleic acid, as a percentage of TG fatty acid in MCF7 and MDA-MB-468 cells (n = 3–7). b Effect of 2 mM metformin increased BODIPY C16 uptake in MCF7 and MDA-MB-231 cells (n = 3). c Effect of 2 mM metformin on ¹³C₁₆-palmitate incorporation into TGFA in MCF7 cells (n = 5–6). d Effect of AICAR on triglyceride fatty acid accumulation in MCF7 cells (n = 3). e Effect of rotenone on triglyceride fatty acid accumulation in MCF7 cells (n = 3). f Effect of siRNA-mediated AMPK knockdown (siAMPK) on exogenous fatty acid accumulation after 48 h of treatment with 2 mM metformin in MCF7 cells (n = 3). g Effect of siAMPK on BODIPY-C16 uptake in control and 2 mM metformin-treated MCF7 cells (n = 3). h Effect of siAMPK on exogenous fatty acid accumulation after 48 h of treatment with 2 mM metformin in MCF7 cells (n = 3). i Effects of AICAR, rotenone and metformin on fatty acid oxidation in MCF7 cells (n = 3). Data shown are mean ± SEM. *P < 0.05; **P < 0.01; ***P < 0.001.