Fibroblast Growth Factor 21 Signaling Activation by Selected Bioactive Compounds from Cocoa Shell Modulated Metabolism and Mitochondrial Function in Hepatocytes

Abstract

Objectives To evaluate the effect of selected bioactive compounds from cocoa shell and its aqueous extract on the activation of fibroblast growth factor 21 (FGF21) signaling in hepatocytes and the resulting modulation of lipid and glucose metabolism, oxidative stress, and mitochondrial function. Methods The bioactive compounds from cocoa shells were extracted using water and characterized by UPLC-MS/MS. An in vitro model of non-alcoholic fatty liver disease was used: HepG2 cells were co-treated with either pure theobromine (TH), protocatechuic acid (PCA), procyanidin B2 (PB2), epicatechin (EPI), catechin (CAT) (10–50 µmol L−1), or the aqueous extract from cocoa shells (CAE, 20–100 µg mL−1) in the presence or absence of palmitic acid (PA, 500 µmol L−1). FGF21 receptor interaction with cocoa shell phytochemical was evaluated in silico. Biomarkers of cell metabolism were assessed 24 h after the co-treatment in cell supernatants and lysates using chemical, biochemical, and immunochemical techniques. Results Phytochemicals from cocoa shell were able to interact in silico with FGF21 receptor (biding energies from −6.0 to −11.0 kcal mol−1) denoting a potential interaction causing FGF21 receptor response. FGF21 hepatic signaling was activated (1.1 to 2.3-fold enhance in ERK1/2 phosphorylation). CAE, TH, PCA, PB2, EPI, and CAT diminished PA-elicited lipid accumulation (5–86%, P < 0.05) by reducing fatty acid synthase expression, and stimulated lipolysis (1–87%, P < 0.05) through the up-regulation of lipoprotein lipase expression. CAE and therein-bioactive compounds, mainly TH and PCA, promoted glucose uptake (4–35%, P < 0.05) via the increase in the phosphorylation of the insulin receptor (2.2-fold, P < 0.05), protein kinase B (2.8-fold, P < 0.05), AMPKα (2.0-fold, P < 0.05), and ERK1/2 (2.8-fold, P < 0.05) phosphorylation. Oxidative stress was prevented (50–100%, P < 0.05), and the loss of mitochondrial content (15–100%, P < 0.05) and function, measured as ATP production, alleviated (28–100%, P < 0.05). Conclusions Results demonstrated that the major bioactive compounds, primarily TH and PCA, found in cocoa shell could activate FGF21 signaling and regulated hepatic lipid and glucose metabolism, preventing insulin resistance, oxidative stress, and mitochondrial dysfunction. Funding Sources USDA-NIFA-HATCH, and the Spanish Ministry of Science and Innovation.

Evaluation of the Hypolipidemic Properties of Cocoa Shell after Simulated Digestion Using In Vitro Techniques and a Cell Culture Model of Non-Alcoholic Fatty Liver Disease

“…Some authors suggested that oxidative stress and mitochondrial dysfunction could be critical factors during NAFLD progression [19]. Previous studies in our group proved the effects of cocoa shell phytochemicals on protecting mitochondrial function and regulating metabolism in hepatocytes [20]. The results obtained suggest the potential role of the cocoa shell in preventing this disease.…”

Phytochemicals from Cocoa Shell Protect Mitochondrial Function and Alleviate Oxidative Stress in Hepatocytes via Regulation of ERK and PI3K-AKT Pathways

“…Mitochondrial dysfunction contributes to NAFLD's pathogenesis since it affects hepatic lipid homeostasis and promotes ROS production, lipid peroxidation, cytokine release, and cell death [16]. Previous studies demonstrated the potential effects of cocoa phytochemicals on hepatic metabolism via activation of the FGF21 signaling cascade [17], which could be associated with NAFLD prevention. Cell metabolic signaling regulation leads to a more functional phenotype in HepG2 cells than palmitic acid treated control.…”

Hypolipidemic Properties of Cocoa and Coffee By-Products after Simulated Gastrointestinal Digestion: A Comparative Approach

“…De novo lipogenesis is elevated during NAFLD, and represents an important source of hepatic and circulating lipids, therefore, a decrease in this activity could lead to a decrease in their levels [24,25].Previous studies have shown that CPE and CSE could have antioxidant effects on HepG2 cell lines, probably due to their phytochemical content. Furthermore, these CSE components have been shown to protect mitochondrial function, closely related to markers associated with metabolic syndrome [11,12,26,27]. Both by-products may be recommended as therapeutic or preventive NAFLD treatments.…”

“…The CS and the CP have been declared safe ingredients, and their characteristics and composition make them a potential source of nutrients and beneficial compounds [5,10]. Previous studies have established a relationship between phytochemicals from both the CS and the CP and the regulation of biomarkers of metabolic syndrome [3,7,11,12]. Recent research proposes that the digestion process positively influences the hypolipidemic properties of both by-products [13,14].…”