Catalpol treatment regulates enzymes and genes involved in lipid metabolism in palmitate- (PA-) treated HepG2 cells. HepG2 cells were treated with PA (300 μM) and/or catalpol (100, 200, or 400 μM) for 24 h. (a) Protein expressions of p-AMP-activated protein kinase (AMPK), p-acetyl-CoA carboxylase (ACC), precursor and mature sterol regulatory element-binding protein 1c (preSREBP-1c and mSREBP-1c, respectively), fatty acid synthase (FAS), peroxisome proliferator-activated receptor α (PPARα), carnitine palmitoyltransferase 1 (CPT1), and acyl-CoA oxidase 1 (ACOX1) were analyzed via Western blotting. (b–d) Densitometric analyses of the band intensity ratios of p-AMPK/AMPK, p-ACC/ACC, preSREBP-1c, mSREBP-1c, FAS, PPARα, CPT1, and ACOX1. Data are presented as the mean ± SE of three independent experiments. ∗∗P < 0.01 vs. the Normal group; #P < 0.05, ##P < 0.01 vs. the PA group.