Dietary isohumulones, the bitter components of beer, raise plasma HDL-cholesterol levels and reduce liver cholesterol and triacylglycerol contents similar to PPARalpha activations in C57BL/6 mice.
The effects of dietary isohumulones, the main components accounting for the bitter taste of beer, on lipid metabolism were examined. Young female C57BL/6N mice were fed diets containing isomerized hop extract (IHE), which consists mainly of isohumulones. Administration of IHE with an atherogenic (high-fat and high-cholesterol) diet for 2 weeks resulted in a significant increase in plasma HDL-cholesterol (P<0.01), along with a concomitant reduction in the atherosclerosis index, an increase in liver weight and a decrease in body weight gain in a dose-dependent manner. When animals received IHE with either a cholesterol or a basal diet for 1 week, significant decreases in the liver content of cholesterol (P<0.01) and triacylglycerol (cholesterol diet, P<0.01) were observed. Quantitative analyses of hepatic mRNA levels revealed that IHE administration resulted in up-regulation of mRNA for acyl-CoA oxidase, acyl-CoA synthetase, hydroxymethylglutaryl-CoA synthetase, lipoprotein lipase and fatty acid transport protein, and down-regulation of mRNA for Apo CIII and Apo AI. Administration of purified isohumulones effectively resulted in the same changes as IHE. Administration of fenofibrate, an agonist for PPARalpha, with a cholesterol diet caused marked hepatomegaly, an increase in plasma HDL-cholesterol, a decrease in hepatic cholesterol content, and alterations in hepatic mRNA levels similar to those observed in mice given IHE. Taken together, these results suggest that the modulation of lipid metabolism observed in mice fed diets containing isohumulones is, at least in part, mediated by activation of PPARalpha.
Miura
Yutaka
Y
Central Laboratories for Key Technology, Kirin Brewery Co. Ltd, Kanazawa-ku, Yokohamashi 236-0004, Japan. yu-miura@kirin.co.jp
Hosono
Mayu
M
Oyamada
Chiaki
C
Odai
Hideharu
H
Oikawa
Shinichi
S
Kondo
Keiji
K
D042962:Acyl-CoA Oxidase / Q000235:genetics; D000818:Animals; D001161:Arteriosclerosis / Q000378:metabolism; D001515:Beer; D002784:Cholesterol / Q000008:administration & dosage / Q000032:analysis* / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood*; D003066:Coenzyme A Ligases / Q000235:genetics; D003517:Cyclopentanes / Q000008:administration & dosage*; D004041:Dietary Fats / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D050612:Fatty Acid Transport Proteins; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D006904:Hydroxymethylglutaryl-CoA Synthase; D008071:Lipoprotein Lipase / Q000235:genetics; D008099:Liver / Q000737:chemistry / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D047493:PPAR alpha / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D014280:Triglycerides / Q000032:analysis* / Q000097:blood
D008076:Cholesterol, HDL; D003517:Cyclopentanes; D004041:Dietary Fats; D050612:Fatty Acid Transport Proteins; D026901:Membrane Transport Proteins; D047493:PPAR alpha; D012333:RNA, Messenger; C493572:Slc27a4 protein, mouse; D014280:Triglycerides; D002784:Cholesterol; C081209:isohumulone; D042962:Acyl-CoA Oxidase; D006904:Hydroxymethylglutaryl-CoA Synthase; D008071:Lipoprotein Lipase; D003066:Coenzyme A Ligases