Inhibition of VEGF expression and secretion by PP mediates its effects on PI3K/AKT pathway.

A. Effects of PP on secretion of VEGF in Huh7 and Hep3B cells. After the cells were treated by PP with various concentrations of (0, 50 or 100 µg/ml) for 48 hr, the conditioned medium were collected and VEGF level in the conditioned medium was determined by a human VEGF ELISA Kit. The result demonstrated a suppression of VEGF secretion in a dose-dependent manner upon PP treatment. B. MTT assay was performed to evaluate the proliferation when exposure to PP (50 µg/ml) in presence or absence of rhVEGF (0.6 ng/ml) for 72 hr in Huh7 cells. C. Huh7 cells were treated with PP (50 µg/ml) alone or the combination with rhVEGF (0.6 ng/ml), and cell lysate was harvested and applied to western blot. Data are expressed as mean ± SD. Significant differences between the PP-treated and untreated cells were statistically analyzed by ANOVA (Tukey's multiple comparison test; *, P<0.01; **, P<0.001).