Mangiferin and EGCG Compounds Fight Against Hyperlipidemia by Promoting FFA Oxidation via AMPK/PPARα

Background: Hyperlipidemia is a critical risk factor for obesity, diabetes, cardiovascular diseases, and other chronic diseases. Our study was to determine the effects and mechanism of mangiferin (MF) and epigallocatechin gallate (EGCG) compounds on improving hyperlipidemia in HepG2 cells. Methods: HepG2 cells were treated with 0.25 mM palmitic acid (PA) and then incubated with MF (12.5, 25, and 50 μM) or EGCG (25, 50, and 100 μM) or MF:EGCG (0:0, 6.25:12.5, 25:50, and 50:100 μM:μM) for 24 h. The improvement of hyperlipidemia was verified by Oil Red O staining, changes in triglyceride (TG) and free fatty acid (FFA) levels, and the expression of lipid metabolizing proteins in western blotting. Results: MF (12.5, 25, and 50 μM) or EGCG (25, 50, and 100 μM) markedly lowered lipid accumulations by lipid index levels. Furthermore, we found that the optimum concentration of MF and EGCG compounds was 25:50 (μM:μM), which significantly reduced the FFA level, TG, and total cholesterol (TC) accumulations and increased FFA uptake in HepG2 cells, and the effect was better than that of single phytochemicals. The adenosine 5⁣'-monophosphate (AMP)-activated protein kinase (AMPK) protein and its downstream proteins sirtuin 1 (SIRT1), peroxisome proliferator-activated receptor α (PPARα), and those involved in fatty acid translocase (CD36) and carnitine palmitoyltransferase 1 (CPT1) were also markedly increased in HepG2 cells. The upregulation of protein expression was reversed when AMPK-specific inhibitor Compound C was added. Conclusions: MF and EGCG (25:50 μM) compounds protect against hyperlipidemia by promoting the FFA oxidation, alleviating TG and TC accumulations via the AMPK/PPARα pathway in PA-treated HepG2 cells.