Antiadipogenic effect of G. cambogia extract and the related protein expression in 3T3-L1 preadipocytes during differentiation. (A) Effect of G. cambogia extract (Ga, 300 μg/ml), FMK (3 μM) and stattic (5 μM) on RPS6KA1 and STAT3 phosphorylation in MDI-induced 3T3-L1 preadipocytes (differentiation started cells) for the indicated times (n = 4 per group). Con: MDI-untreated cells, MDI: MDI-treated cells. **p < 0.01 vs. Con, ##p < 0.01 vs. MDI. (B) Kinase activity of MAPK3/ERK1 and JAK2 in response to G. cambogia extract (n = 4 per group). The active MAPK3/ERK1 and JAK2 enzymes were used to assess kinase activity in the presence or absence of G. cambogia extract at the indicated concentrations in vitro. *p < 0.05 and **p < 0.01 vs. each control. (C) Effect of G. cambogia extract (300 μg/ml), FMK (3 μM) and stattic (5 μM) on CEBPA and PPARG expression in mature 3T3-L1 adipocytes (fully differentiated adipocytes) (n = 4 per group). Con: undifferentiated cells, Diff: mature 3T3-L1 adipocytes. **p < 0.01 vs. Con, ##p < 0.01 vs. Diff. (D) Effect of G. cambogia extract (300 μg/ml) on lipid accumulation in mature 3T3-L1 adipocytes at the indicated time points. The time table (upper) and representative images of Oil red O staining (below) are presented. EGCG (50 μM) was used as a positive control (n = 15 per group). Scale bar: 50 μm. (E) Effect of G. cambogia extract (300 μg/ml) on CEBPA and PPARG expression in mature 3T3-L1 adipocytes at the indicated time points (n = 4 per group). *p < 0.05 and **p < 0.01 vs. each group. The data are the mean ± S.D.