FIGURE 3. Metformin inhibited adipocyte differentiation.

3T3L1 mouse preadipocytes were differentiated over a period of 9 days. One set was treated from day 0 (A) or day 3 (B) with various concentrations of metformin (1-5mM). Differentiation of adipocytes was monitored by accumulation of lipid droplets visualized by Oil Red O staining. The accumulated lipid droplets were quantified by coloriemeteric absorbance (Ci, Cii) (##p < 0.001 compared to undifferentiated preadipocytes (undiff); *p < 0.05, **p < 0.01, ***p < 0.001 compared to Diff: untreated differentiated adipocytes).