title: Effects of a catechin-free fraction derived from green tea on gene expression of enzymes related to lipid metabolism in the mouse liver.
abstract: Many biological activities of green tea have been attributed to a major constituent, (minus;)-epigallocatechin gallate (EGCG). We previously reported that EGCG and an EGCG-free fraction derived from green tea modulated the gene expression of gluconeogenic enzymes, glucose-6-phosphatase and phosphoenolpyruvate carboxykinase, in the mouse liver. EGCG is also known to affect the gene expression of enzymes related to lipid metabolism. However, it remains to be examined whether or not a constituent other than EGCG contributes to the change in gene expression of these enzymes. In this study, we prepared an EGCG-free water-soluble fraction (GT-W), and examined its effects on the hepatic gene expression of lipogenic enzymes in mice. The results of quantitative real-time PCR assays indicated that the dietary administration of GT-W for 4 weeks reduced the hepatic gene expression of lipogenic enzymes: fatty acid synthase, hydroxymethylglutaryl coenzyme A reductase, and acetyl-coenzyme A carboxylase alpha. Also, the gene expression of sterol regulatory element-binding transcription factor (Srebf)1 and/or Srebf2 was reduced, suggesting that the reduction of Srebfs contributed to the down-regulation of the lipogenic enzymes, since these transcription factors bind the promoter region to enhance their expression. The plasma levels of triglycerides and cholesterol were reduced with statistical significance in the group given a diet containing GT-W. These results suggest that in addition to EGCG, green tea contains some component(s) which may help to prevent arteriosclerosis and obesity.
authors.affiliation: Health Care Research Center, Nisshin Pharma Inc., Fujimino, Saitama 356-8511, Japan.
authors.forename: Kensuke
authors.initials: K
authors.lastname: Yasui
authors.forename: Noriko
authors.initials: N
authors.lastname: Paeng
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Miyoshi
authors.forename: Takuji
authors.initials: T
authors.lastname: Suzuki
authors.forename: Kyoko
authors.initials: K
authors.lastname: Taguchi
authors.forename: Yoko
authors.initials: Y
authors.lastname: Ishigami
authors.forename: Ryuuta
authors.initials: R
authors.lastname: Fukutomi
authors.forename: Shinjiro
authors.initials: S
authors.lastname: Imai
authors.forename: Mamoru
authors.initials: M
authors.lastname: Isemura
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Nakayama
mesh_terms: D000818:Animals; D001161:Arteriosclerosis / Q000235:genetics / Q000517:prevention & control; D001786:Blood Glucose / Q000032:analysis; D002392:Catechin / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D002784:Cholesterol / Q000097:blood; D015536:Down-Regulation / Q000187:drug effects; D005952:Glucose-6-Phosphatase / Q000235:genetics / Q000378:metabolism; D050356:Lipid Metabolism / Q000235:genetics*; D008099:Liver / Q000187:drug effects* / Q000201:enzymology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009765:Obesity / Q000235:genetics / Q000517:prevention & control; D019764:Phosphoenolpyruvate Carboxykinase (ATP) / Q000235:genetics / Q000378:metabolism; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D060888:Real-Time Polymerase Chain Reaction; D051780:Sterol Regulatory Element Binding Protein 1 / Q000235:genetics / Q000378:metabolism; D051782:Sterol Regulatory Element Binding Protein 2 / Q000235:genetics / Q000378:metabolism; D013662:Tea / Q000737:chemistry*; D014280:Triglycerides / Q000097:blood
chemical_list: D001786:Blood Glucose; D010936:Plant Extracts; C497388:Srebf1 protein, mouse; C497391:Srebf2 protein, mouse; D051780:Sterol Regulatory Element Binding Protein 1; D051782:Sterol Regulatory Element Binding Protein 2; D013662:Tea; D014280:Triglycerides; D002392:Catechin; D002784:Cholesterol; C045651:epigallocatechin gallate; D005952:Glucose-6-Phosphatase; D019764:Phosphoenolpyruvate Carboxykinase (ATP)