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

Fig. 2. Effects of ginseng seed oil (GSO) on lipid accumulation in HepG2 cells and primary rat hepatocytes. (A) Oil Red O staining of HepG2 cells after free fatty acids (FFA)-induced accumulation of lipid droplets. HepG2 cells were pre-treated with GSO for 2 h and incubated with 1mM FFA for 24 h. Scale = 100 μm. (B) Relative intracellular lipid level was determined in HepG2 cells by spectrophotometric quantification of oil red O dye at 540 nm. (C) Intracellular triglyceride (TG) content was measured in HepG2 cells. (D) Oil red O staining of isolated rat hepatocytes after 3 weeks of high-fat diet (HFD) feeding. The hepatocytes were treated with GSO for 24 h as indicated. (E) Relative intracellular lipid level was determined in rat hepatocytes by spectrophotometric quantification of oil red O dye at 540 nm. (F) Intracellular TG content was measured in hepatocytes using commercial kit. Each bar represents the mean ± standard deviation of three independent experiments in triplicate.*p < 0.05; **p < 0.01 versus FFA-treated cells; ***p < 0.001 versus hepatocytes of HFD-fed rat. MET, metformin.

Fig. 1. Chromatographic profile of fatty acids detected from ginseng seed oil extracted by pressing method using 5-year-old ginseng seeds. 1: palmitic acid (2.01%), 2: palmitoleic acid (0.25%), 3: oleic acid (76.12%), 4: linoleic acid (17.33%).

Fig. 3. Effects of ginseng seed oil (GSO) on high-fat diet (HFD)-induced changes in C57BL/6J mice. (A, B) Weekly body weight change was measured, and the body weight gain was calculated. (C) Serum lipid profiles including total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were measured. (D) The ratio of LDL-C over HDL-C was calculated. (E, F) Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured as liver toxicity parameters. *p < 0.05; **p < 0.01; ***p < 0.001 versus HFD. MET, metformin; RD, regular diet.

Fig. 4. Effects of ginseng seed oil (GSO) on high-fat diet (HFD)-induced hepatic lipid accumulation in mice. (A) Histological analysis of the liver by hematoxylin and eosin staining. Scale = 50 μm. (B–D) Liver weight, lipid contents and triglyceride levels were measured.∗p < 0.05; ∗∗p < 0.01 versus HFD. MET, metformin; RD, regular diet.

Fig. 5. Effects of ginseng seed oil on high-fat diet (HFD)-induced insulin resistance in mice. (A) Fasting glucose and (B) insulin levels were measured in the serum of mice. (C) Homeostatic Model Assessment of Insulin Resistance Index (HOMA-IR)was calculated using the following formula: fasting insulin (μU/L) × fasting glucose (nmol/L)/22.5.*p < 0.05; **p < 0.01; ***p < 0.001 versus HFD.GSO, ginseng seed oil; MET, metformin; RD, regular diet.

Fig. 6. Effects of ginseng seed oil (GSO) on high-fat diet (HFD)-induced hepatic gene expression in mice. (A) Gene set enrichment analysis plot of 88 genes significantly down-regulated by HFD feeding within genes ranked log2-fold change in GSO versus HFD. (B) Gene set enrichment analysis of 35 upregulated genes in HFD versus regular diet (RD) as compared to genes ranked log2-fold change in GSO versus HFD. (C) Heatmap displaying expression level of genes involved in lipid metabolism and hepatic inflammation. Genes up- and down-regulated are depicted in red and blue, respectively. Reverse transcription–quantitative polymerase-chain reaction validation was performed on the target genes of GSO involved in (D) β-oxidation, (F) lipogenesis, and (F) hepatic inflammation.*p < 0.05; **p < 0.01 versus HFD. FDR, false discovery rate; mRNA, messenger RNA; NES, normalized enrichment score.

Fig. 7. Expression pattern of genes related to fatty acid degradation pathway (Kyoto Encyclopedia of Genes and Genomes entry: mmu00071) in the liver from ginseng seed oil-treated mice. Genes up- and downregulated are depicted in red and blue, respectively. HFD, high fat diet; RD, regular diet; TCA, tricarboxylic acid.