Abstract
BACKGROUND: (E)-5-hydroxy-7-methoxy-3-(2-hydroxybenzyl)-4-chromanone (HMC), a homoisoflavonoid isolated from Portulaca oleracea, has significant anti-adipogenesis potential; it regulates adipogenic transcription factors. However, whether HMC improves hepatic steatosis in hepatocytes remains vague. This study investigated whether HMC ameliorates hepatic steatosis in free fatty acid-treated human hepatocellular carcinoma (HepG2) cells, and if so, its mechanism of action was analyzed. METHODS: Hepatic steatosis was induced by a free fatty acid mixture in HepG2 cells. Thereafter, different HMC concentrations (10, 30, and 50 µM) or fenofibrate (10 µM, a PPARα agonist, positive control) was treated in HepG2 cells. RESULTS: HMC markedly decreased lipid accumulation and triglyceride content in free fatty acid-treated HepG2 cell; it (10 and 50 μM) markedly upregulated protein expressions of pAMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase. HMC (10 and 50 μM) markedly inhibited the expression of sterol regulatory element-binding protein-1c, fatty acid synthase, and stearoyl-coA desaturase 1, which are the enzymes involved in lipid synthesis. Furthermore, HMC (10 and 50 μM) markedly upregulated the protein expression of peroxisome proliferator-activated receptor alpha (PPARα) and enhanced the protein expressions of carnitine palmitoyl transferase 1 and acyl-CoA oxidase 1. CONCLUSION: HMC inhibits lipid accumulation and promotes fatty acid oxidation by AMPK and PPARα pathways in free fatty acid-treated HepG2 cells, thereby attenuating hepatic steatosis.