Xn and Xc activate AMPK in L6 myotubes.

<p>The xanthene derivatives Xn (a), Xc (b) and metformin (c) increased phosphorylation of AMPK<i>a</i>2 thr-172 and ACC ser-79 in a dose-dependent manner. The indicated concentration was administered for 5 min for Xn and Xc, and 2 h for metformin. (d) Concentration–effect curves of three AMPK activators. Each curve is based on quantification of individual experiments allowing comparison of the effective concentration between metformin and xanthene derivatives. The time-dependent phosphorylation trend of AMPK <i>a</i>2 thr-172 following treatment with the xanthene derivatives Xn (e) and Xc (f). A 5 µM concentration of xanthene derivatives was administered to L6 myotubes at the indicated time point. The numbers indicate min following administration. (g) The graph shows the time-dependent trend in AMPK-phosphorylation induced by Xn and Xc. Western blot data represent one of three independent experiments. Values shown in graphs are means ± SE from three independent experiments.