PF activated the AMPK/SIRT1/PGC-1α signaling pathway in C2C12 myoblasts induced by TNF-α. (A) Representative immunoblots using antibodies against p-AMPKα (Thr172), AMPKα, SIRT1, PGC-1α and GAPDH. (B) Quantification of protein expression. (C) The mRNA level of PGC-1α was assessed with RT–qPCR. (D) Cytotoxicity of Compound C (0, 2.5, 5, 7.5, 10, 12.5 and 15 μM) for 24 h (n = 6). (E) Cytotoxicity of EX-527 (0, 5, 10, 15, 20, 25 and 30 μM) for 24 h (n = 6). (F) The effect of different concentrations of Compound C on p-AMPKα/AMPKα protein levels. (G) The effect of different concentrations of EX-527 on SIRT1 protein inhibition. *
p < 0.05, **
p < 0.01, ***
p < 0.001 compared with the compound or EX-527 0 μM group. (H) Representative immunoblots using antibodies against MAFbx, MuRF-1, p-AMPKα (Thr172), AMPKα, SIRT1, PGC-1α and GAPDH. (I, J) Quantification of protein expression. All protein expression was normalized to that of GAPDH as a loading control. The data are presented as the means ± S.D. n = 3, *
p < 0.05, **
p < 0.01, ***
p < 0.001 compared with the Control group. #
p < 0.05, ##
p < 0.01, ###
p < 0.001 compared with the TNF-α 40 ng/ml group, &
p < 0.05, &&
p < 0.01, &&&
p < 0.001 compared with the TNF-α 40 ng/ml + PF 50 μM group.