Hovenia Dulcis Extract Reduces Lipid Accumulation in Oleic Acid-Induced Steatosis of Hep G2 Cells via Activation of AMPK and PPARα/CPT-1 Pathway and in Acute Hyperlipidemia Mouse Model.

Hovenia dulcis Thunb. (HDT) was known to have anti-fatigue, anti-diabetes, neuroprotective, and hepatoprotective effects. In the present study, the anti-fatty liver mechanism of HDT was elucidated in oleic acid (OA)-treated Hep G2 cells and acute hyperlipidemia mouse model using Triton WR-1339. Here, HDT activated p-AMP-activated protein kinase (p-AMPK), proliferator activated receptor-α, carnitine palmitoyltransferase and also inhibited the expression of lipogenesis and cholesterol synthesis proteins, such as 3-hydroxy-3-methylglutaryl-CoA reductase, sterol regulatory element binding protein-1c, SREBP-2, and fatty acid synthase in OA-treated Hep G2 cells. Conversely, AMPK inhibitor compound C blocked the anti-fatty liver effect of HDT to induce AMPK phosphorylation and decrease 3-hydroxy-3-methylglutaryl-CoA reductase and lipid accumulation by oil red O staining in OA-treated Hep G2 cells. Additionally, HDT pretreatment protected against the increase of serum total cholesterol, triglyceride, low-density lipoprotein cholesterol and phospholipid in an acute hyperlipidemia mouse model with enhancement of glutathione reductase, glutathione peroxidase, superoxide dismutase, and catalase activities. Taken together, HDT inhibits OA-induced hepatic lipid accumulation via activation of AMPK and proliferator activated receptor-α/carnitine palmitoyltransferase signaling and enhancement of antioxidant activity as a potent candidate for nonalcoholic fatty liver disease and hyperlipidemia.