title: High dose of dietary resveratrol enhances insulin sensitivity in healthy rats but does not lead to metabolite concentrations effective for SIRT1 expression.
abstract: METHODS
  trans-Resveratrol has been shown to improve insulin sensitivity and to enhance cellular glucose uptake. Evidence from recent studies indicates that these effects depend on SIRT1-pathways.
  
  
  RESULTS
  Since ingestion of resveratrol leads to the presence of resveratrol and resveratrol metabolites in the body, we aimed at investigating (i) whether a daily dose of 300 mg resveratrol/kg body weight in healthy male Wistar rats for a period of 8 wk affects the selected parameters of glucose and lipid metabolism and (ii) whether the resulting plasma concentrations of resveratrol metabolites were effective in modulating SIRT1 expression. The dietary dose was based on the results from preceding toxicity studies. The results from the feeding experiment revealed plasma concentrations of resveratrol and its metabolites below 1 μmol/L and showed that fasting glucose and insulin levels were decreased by 35 and 41%, respectively, in the resveratrol group compared with controls. Insulin sensitivity was enhanced by 70%, whereas liver SIRT1 protein expression was not affected. Treatment of HepG2 cells with 10 μM resveratrol (1.49-fold) or its diglucuronides (1.21-fold) increased SIRT1 expression.
  
  
  CONCLUSIONS
  These results suggest that the improved insulin sensitivity after dietary administration of 300 mg resveratrol/kg body weight does not involve increased protein expression of SIRT1.
authors: German Research Center for Food Chemistry, Freising, Germany.
authors: Gaby
authors: G
authors: Andersen
authors: Alexander
authors: A
authors: Burkon
authors: Florian J
authors: FJ
authors: Sulzmaier
authors: Joel M
authors: JM
authors: Walker
authors: Gunhild
authors: G
authors: Leckband
authors: Rainer
authors: R
authors: Fuhst
authors: Helmut F
authors: HF
authors: Erbersdobler
authors: Veronika
authors: V
authors: Somoza
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D002784:Cholesterol / Q000378:metabolism; D005230:Fatty Acids, Nonesterified / Q000378:metabolism; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D056945:Hep G2 Cells; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008099:Liver / Q000378:metabolism; D008297:Male; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D000077185:Resveratrol; D056564:Sirtuin 1 / Q000032:analysis / Q000235:genetics*; D013267:Stilbenes / Q000378:metabolism / Q000494:pharmacology* / Q000633:toxicity; D014280:Triglycerides / Q000378:metabolism
chemical_list: D001786:Blood Glucose; D002784:Cholesterol; D005230:Fatty Acids, Nonesterified; D006442:Glycated Hemoglobin; D007328:Insulin; D012333:RNA, Messenger; D000077185:Resveratrol; D056564:Sirtuin 1; D013267:Stilbenes; D014280:Triglycerides; C447939:SIRT1 protein, human; C488368:Sirt1 protein, rat