Ginseng seed oil ameliorates hepatic lipid accumulation in vitro and in vivo

BACKGROUND: Despite the large number of studies on ginseng, pharmacological activities of ginseng seed oil (GSO) have not been established. GSO is rich in unsaturated fatty acids, mostly oleic and linoleic acids. Unsaturated fatty acids are known to exert a therapeutic effect in nonalcoholic fatty liver disease (NAFLD). In this study, we investigated the protective effect and underlying mechanisms of GSO against NAFLD using in vitro and in vivo models. METHODS: In vitro lipid accumulation was induced by free fatty acid mixture in HepG2 cells and by 3 wk of high fat diet (HFD)-feeding in Sprague–Dawley rats prior to hepatocyte isolation. The effects of GSO against diet-induced hepatic steatosis were further examined in C57BL/6J mice fed a HFD for 12 wk. RESULTS: Oil Red O staining and intracellular triglyceride levels showed marked accumulation of lipid droplets in both HepG2 cells and rat hepatocytes, and these were attenuated by GSO treatment. In HFD-fed mice, GSO improved HFD-induced dyslipidemia and hepatic insulin resistance. Increased hepatic lipid contents were observed in HFD-fed mice and it was lowered in GSO (500 mg/kg)-treated mice by 26.4% which was evident in histological analysis. Pathway analysis of hepatic global gene expression indicated that GSO increased the expression of genes associated with β-oxidation (Ppara, Ppargc1a, Sirt1, and Cpt1a) and decreased the expression of lipogenic genes (Srebf1 and Mlxipl), and these were confirmed with reverse transcription and quantitative polymerase-chain reaction. CONCLUSION: These findings suggest that GSO has a beneficial effect on NAFLD through the suppression of lipogenesis and stimulation of fatty acid degradation pathway.