Protective effect of resveratrol derivatives on high-fat diet induced fatty liver by activating AMP-activated protein kinase

Non-alcoholic fatty liver disease is associated with inhibited AMP-activated kinase (AMPK) and activation of sterol regulatory element binding protein 1 (SREBP-1). AMPK phosphorylation inhibits SREBP-1, a major transcription factor of de novo lipogenesis, by inhibiting the liver X receptor (LXR) or by direct phosphorylation. Resveratrol, a polyphenol, has regulatory effects on hepatic lipid metabolism as a potent AMPK activator. In this study, we evaluated the anti-steatogenic effects of resveratrol and its derivatives and identified the molecular mechanism in vitro and in vivo. Resveratrol and its derivatives decreased lipid accumulation by free fatty acids (FFA mixture; 0.5 mM, oleic acid:palmitic acid = 2: 1) in H4IIEC3 cells. Synthesized derivatives of resveratrol had lower cytotoxicity than the parental molecule with similar potency. SY-102 suppressed SREBP-1 maturation by T0901317, an LXR agonist, and decreased SRE luciferase activity and the mRNA levels of lipogenic genes. Inhibition of AMPK by pre-treatment with compound C completely blocked the effects of SY-102. To evaluate their efficacy in vivo, mice were fed a high-fat diet for 5 days, and resveratrol or SY-102 was administered orally for the last 2 days. Oral administration of the SY-102 increased AMPK phosphorylation, followed by reduced hepatic triglyceride accumulation to a similar extent as resveratrol. These data demonstrate that SY-102, a synthesized derivative of resveratrol, might provide a promising therapeutic effect against fatty liver disease.