Figure 5.

Regulative effects of pure phytochemicals from the cocoa shell (50 µmol L⁻¹), aqueous extract (CAE, 100 µg mL⁻¹), and FGF21 (20 nmol L⁻¹), in the presence of palmitic acid (500 µmol L⁻¹), on the mitochondrial function of HepG2 human hepatocytes. Cocoa shell phytochemicals attenuated the loss of mitochondrial mass (A) and mitochondrial function as measured by citrate synthase (CS) activity (B), oxidative phosphorylation (OXPHOS) complex I (CI) activity (C), O₂ consumption rate (D), and ATP production (E). HepG2 cells exhibited modulated AMPK expression and phosphorylation (F), as shown in Western blot results (G). PGC-1α (H), and mitochondrial OXPHOS complexes (I) protein expression were also regulated. Hierarchical cluster analysis and heat map (from the lowest () to the highest () value for each parameter) (J) and an integrative diagram illustrating the effects of the phytochemicals from the cocoa shell on mitochondrial function (K). The results are expressed as mean ± SD (n = 3). Bars with different letters (a–e) significantly (p < 0.05) differ according to ANOVA and Tukey’s multiple range test. NT: non-treated cells; PA: palmitic acid; TH: theobromine; PCA: protocatechuic acid; PB2: procyanidin B2; EPI: epicatechin; CAT: catechin; FGF21: fibroblast growth factor 21.