Effects of Citrus Auraptene (7-Geranyloxycoumarin) on Hepatic Lipid Metabolism in Vitro and in Vivo

Recent reports have shown that citrus auraptene (7-geranyloxycoumarin) possesses valuable pharmacological properties, including anticarcinogenic, anti-inflammatory, antihelicobacter, antigenotoxic, and neuroprotective effects. In the present study, we investigated the effect of dietary auraptene on hepatic lipid metabolism both in vitro and in vivo. Results suggested that auraptene has the ability to normalize lipid abnormalities in HepG2 hepatocytes. After 4 weeks of auraptene feeding, abdominal white adipose tissue weight and hepatic triglyceride (TG) levels were dose-dependently lowered in Otsuka Long-Evans Tokushima fatty (OLETF) rats. The activities of carnitine palmitoyltransferase, a key enzyme in mitochondrial fatty acid beta-oxidation, and peroxisomal beta-oxidation were markedly and dose-dependently enhanced in OLETF rat livers by auraptene feeding. Additionally, hepatic expression of acyl-CoA oxidase, the initial enzyme of the peroxisomal beta-oxidation system, was significantly and dose-dependently enhanced by auraptene administration. These results suggest that auraptene administration alleviates obesity and hepatic TG accumulation in part through lipolysis enhancement in the livers of obese OLETF rats.