食品成分による肝臓脂肪酸酸化と合成系の制御  [in Japanese] Nutritional Regulation of Hepatic Fatty Acid Oxidation and Synthesis  [in Japanese]

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Author(s)

    • 井手 隆 IDE Takashi
    • 独立行政法人食品総合研究所食品機能部栄養化学研究室 Laboratory of Nutritional Biochemistry, Division of Food Functionality, National Food Research Institute

Abstract

食品成分が肝臓脂肪酸酸化と合成系に与える影響をラットで系統的に追究した。大豆リン脂質は肝臓のトリグリセリド合成を著減させる。この低下は脂肪酸合成低下が主要因となり引き起こされることを明らかとした。卵黄やサフラワー種子リン脂質も同様な生理作用をもつことを示し, また脂肪酸合成低下は脂肪酸合成系酵素の遺伝子発現の変化によることも明確にした。α-リノレン酸の血清脂質濃度低下作用の発現機構に関連し, ミトコンドリアとペルオキシゾームの脂肪酸酸化系酵素の基質特異性とα-リノレン酸摂取によるβ酸化系酵素活性と遺伝子発現増加が, 大きな役割を果たすことを明確にした。ゴマに含まれるリグナンであるセサミンの血清脂質低下作用発現機構に関し, セサミンが強力な肝臓β酸化酵素の活性上昇と遺伝子発現誘導作用をもつことを示した。また, セサミンは脂肪酸合成系酵素遺伝子発現を低下させ, この低下に転写因子ステロール調節エレメント結合タンパク質-1 (SREBP-1) 遺伝子発現低下とその活性化抑制が関与することを示した。

Effects of various dietary factors on the activity and gene expression of hepatic enzymes in fatty acid synthesis and oxidation were examined in the rat. Dietary soybean phospholipid profoundly decreased hepatic triacylglycerol synthesis accompanying by a marked reduction in the activity and mRNA levels of enzymes involved in fatty acid synthesis. Phospholipids from egg yolk and safflower seed origin showed similar physiological activity in reducing hepatic lipogenesis. Dietary fats rich in α-linolenic acid compared to saturated fats and a fat rich in linoleic acid increased the activity and gene expression of hepatic enzymes in fatty acid oxidation. The β-oxidation rate of α-linolenic acid, relative to palmitic and linoleic acids, was higher in both the mitochondrial and peroxisomal pathways. It was suggested that both substrate specificity and alterations in the activities of the enzymes in the β-oxidation pathway play a significant role in regulating serum lipid concentrations in rats fed α-linolenic acid. Sesamin, a sesame lignan, was found to be a potent inducer of hepatic fatty acid oxidation. Sesamin dose-dependently and profoundly increased the activity and gene expression of hepatic fatty acid oxidation enzymes. Sesamin also showed the physiological activity in reducing gene expression of hepatic lipogenic enzymes through the down-regulation of sterol element binding protein-1. Therefore, it is apparent that dietary sesamin reduces serum lipid levels through alterations in both hepatic fatty acid oxidation and synthesis.

Journal

  • Nippon Eiyo Shokuryo Gakkaishi

    Nippon Eiyo Shokuryo Gakkaishi 55(2), 105-110, 2002-04-10

    Japan Society of Nutrition and Food Science

References:  25

Codes

  • NII Article ID (NAID)
    10008561329
  • NII NACSIS-CAT ID (NCID)
    AN00311992
  • Text Lang
    JPN
  • Article Type
    REV
  • ISSN
    02873516
  • NDL Article ID
    6148861
  • NDL Source Classification
    ZS8(科学技術--医学--解剖学・生理学・生化学)
  • NDL Call No.
    Z19-53
  • Data Source
    CJP  NDL  J-STAGE 
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