Comparison between phytoceramide and PHS in PPAR activation. NIH/3T3 cells were transfected as described for Figure 2A. PHS was dissolved in DMSO to carry out the experiments under the same condition with phytoceramide. Transfected cells were treated with phytoceramide or PHS at the indicated concentrations for 24 h, and then the luciferase activity was quantified. All results are shown as means ± S.D. (n = 3). *P < 0.05, **P < 0.01, ***P < 0.001, significantly different from the level of vehicle control.