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标题：Inhibitory Mechanisms of Flavonoids on Insulin-Stimulated Glucose Uptake in MC3T3-G2/PA6 Adipose Cells
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作者：Masaaki Nomura ; Tatsuo Takahashi ; Naoto Nagata 等
期刊名称：Biological and Pharmaceutical Bulletin
印刷版ISSN：0918-6158
电子版ISSN：1347-5215
出版年度：2008
卷号：31
期号：7
页码：1403-1409
DOI：10.1248/bpb.31.1403
出版社：The Pharmaceutical Society of Japan
摘要：We assessed the effects of different classes of flavonoids on insulin-stimulated 2-deoxy- D -[1-³H]glucose uptake by mouse MC3T3-G2/PA6 cells differentiated into mature adipose cells. Among the flavonoids examined, the flavones, apigenin and luteolin, the flavonols, kaempferol, quercetin and fisetin, an isoflavone, genistein, a flavanonol, silybin, and the flavanols, (−)-epigallocatechin gallate (EGCG) and theaflavins, significantly inhibited insulin-stimulated glucose uptake. Key structural features of flavonoids for inhibition of insulin-stimulated glucose uptake are the B-ring 4′- or 3′,4′-OH group and the C-ring C2–C3 double bond of the flavones and flavonols, the A-ring 5-OH of isoflavones, and the galloyl group of EGCG and theaflavins. Luteolin significantly inhibits insulin-stimulated phosphorylation of insulin receptor-β subunit (IR-β), and apigenin, kaempferol, quercetin and fisetin, also tended to inhibit the IR-β phosphorylation. On the other hand, isoflavones, flavanols or flavanonols did not affect insulin-stimulated IR-β phosphorylation. Apigenin, luteolin, kaempferol, quercetin and fisetin also appeared to inhibit insulin-stimulated activation of Akt, a pivotal downstream effector of phosphatidylinositol 3-kinase (PI3K), and suppressed insulin-dependent translocation of a glucose transporter, (GLUT)4, into the plasma membrane. Although genistein, silybin, EGCG and theaflavins had no effect on the insulin-stimulated activation of Akt, they blocked insulin-dependent GLUT4 translocation. These results provide novel insights into the modulation by flavonoids of insulin's actions, including glucose uptake in adipocytes.
关键词：flavonoid;adipocyte;glucose uptake;insulin;Akt;glucose transporter 4