Nonalcoholic fatty liver disease (NAFLD) is a common chronic liver disease that is closely related to metabolic syndrome. We investigated the effect of a Psoralea corylifolia L. (PC) seeds extract (PCE) on NAFLD. PC seeds were extracted using different ethanol concentrations to produce five extracts, and the 70% ethanol PCE, which had the highest phenolic content, was used in subsequent in vitro and in vivo experiments. The inhibitory effect of PCE on hepatic steatosis was estimated using HepG2 cells treated with oleic acid (OA). In addition, an in vivo NAFLD model was established using high-fat diet (HFD)-induced obese C57BL/6 mice. Obesity was induced in mice over 14 weeks. PCE (100 or 200 mg/kg/day) was administered orally to mice after 8 weeks of the 14-week treatment period for 6 weeks. PCE suppressed lipid accumulation in OA-treated HepG2 cells. PCE ameliorated the antioxidant activity suppressions induced by the HFD. In addition, both PCE100 and PCE200 groups reduced lipid accumulation and the expression levels of inflammatory proteins as compared with HFD group. PCE administration significantly attenuated hepatic steatosis in liver tissues by decreasing the expression of lipogenic protein sterol regulatory element binding protein 1-c (SREBP-1c) and its downstream protein fatty acid synthase (FAS) in HFD-fed mice and in OA-treated HepG2 cells. Furthermore, PCE administration increased the phosphorylation of AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase. These results suggest that PCE could be used as a functional material to prevent or ameliorate NAFLD by inhibiting lipid accumulation in liver. PRACTICAL APPLICATION: Psoralea corylifolia L. is rich in polyphenol and other phytochemicals. In this study, we identified the beneficial effects of Psoralea corylifolia L. extract on hepatic steatosis in oleic-acid-induced HepG2 cells and high-fat diet-fed mice. The result of this study will provide the evidence that a Psoralea corylifolia L. extract has potential use as a functional material for the prevention and amelioration of nonalcoholic fatty liver disease.
