OBJECTIVETo study the effect of resveratrol on the nonalcoholic fatty liver (NAFL).

METHODSThirty Wistar rats were allocated into three groups (10 for each): a normal control group (NC, fed with standard chow), a high fat feeding group (HF, fed with a high fat diet) and a resveratrol treated group (RT). The RT rats were fed a high fat diet all the time (as the HF) and received resveratrol administration (100 mg . kg-1. d-1) started on the 6th week of the experiment. The experiment lasted for 16 weeks. Then all the rats were sacrificed and hyperinsulinemic-euglycemic clamp was performed to evaluate insulin sensitivity. Liver histology was studied by HE stained microscopic preparations of the livers. Phosphorylation of AMP-activated protein kinase (AMPK) levels were determined by Western blot.

RESULTSCompared to the NC, visceral fat index and liver mass index was lower and fasting serum insulin (FINS) was higher and glucose infusion rate (GIR) was lower in the HF (t=10.554, P less than 0.01). Severe liver steatosis was observed microscopically in the HF. In addition, phosphorylation of AMPK levels in the HF was 45.8% lower than that of the NC (t=8.384, P less than 0.01). Compared with the HF, the visceral fat index, liver mass index, FINS and GIR were all much lower, and the liver steatosis was milder than those in the RT. Further phosphorylation of AMPK seen was 70.2% higher in RT compared with that in the NC (t=3.816, P less than 0.01).

CONCLUSIONResveratrol administration improved high-fat feeding induced insulin resistance and fatty liver by activating AMPK.