Figure 1

Anthocyanin activates AMPK in cultured HepG2 cells. (A) HepG2 cells were treated with various concentrations of Cy-3-g or AICAR (1 mM) for 1 h. The cells were then lysed, and 100 μg of the cell lysates underwent SDS-PAGE followed by Western blot analysis for AMPK phosphorylation. (B) Two microgram of protein extracts were subjected to AMPK activity assays with SAMS peptide as substrates, results are expressed as nmoles ATP/mg protein/min. *P < 0.05 or **P < 0.01 compared to control. (C) GPPase activity was measured in the presence of glycogen using a phosphoglucomutase and glucose-6 phosphate dehydrogenase-coupled spectrophotometric method. Effects of anthocyanin are expressed as a percent of the maximum stimulation achieved by AMP. (D) FBPase activity was determined using the substrate D-fructose-1,6-bisphosphate and colorimetric detection of free phosphate. Results are expressed as percent inhibition relative to vehicle control. (E) The concentration-dependent AMPK activation by anthocyanin and additive effects in the presence of 300 μM AMP. *P < 0.05 compared to vehicle. (F) AMP dose-responsive AMPK activation and additive effects in the presence of 100 μM Cy-3-g. *P < 0.05 compared to vehicle. The results presented in panels (B) through (F) are means ± SE from experiments run in triplicate and are representative of at least three independent experiments.