Arao Keisuke, Wang Yu-Ming, Inoue Nao, Hirata Junichi, Cha Jae-Young, Nagao Koji, Yanagita Teruyoshi
Department of Applied Biological Sciences, Saga University, Saga 840-8502, Japan.
Lipids Health Dis. 2004 Nov 9;3:24. doi: 10.1186/1476-511X-3-24.
Conjugated fatty acid, the general term of positional and geometric isomers of polyunsaturated fatty acids with conjugated double bonds, has attracted considerable attention because of its potentially beneficial biological effects. In the present study, dietary effect of pomegranate seed oil rich in punicic acid (9cis, 11trans, 13cis-conjugated linolenic acid; 9c, 11t, 13c-CLNA) on lipid metabolism was investigated in obese, hyperlipidemic Otsuka Long-Evans Tokushima Fatty (OLETF) rats. After 2 weeks feeding period, OLETF rats revealed obesity and hyperlipidemia compared with their progenitor LETO rats. Feeding of the diet supplemented with 9% safflower oil and 1% pomegranate seed oil (9c, 11t, 13c-CLNA diet) did not affect abdominal white adipose tissue weights and serum lipid levels compared with the diet supplemented with 10% safflower oil (control diet) in OLETF rats. However, the accumulated hepatic triacylglycerol was markedly decreased by 9c, 11t, 13c-CLNA diet in OLETF rats. Activities of hepatic enzymes related to fatty acid synthesis and fatty acid beta-oxidation were not altered by 9c, 11t, 13c-CLNA diet. Levels of monounsaturated fatty acid (MUFA), major storage form of fatty acid, in serum triacylglycerol were markedly higher in obese, hyperlipidemic OLETF rats than in lean LETO rats. In addition, 9c, 11t, 13c-CLNA diet significantly decreased MUFA levels in OLETF rats. This is the first study showing that 9c, 11t, 13c-CLNA suppresses delta-9 desaturation in vivo, and we suggest that the alleviation of hepatic triacylglycerol accumulation by 9c, 11t, 13c-CLNA diet was, at least in part, attributable to the suppression of delta-9 desaturation in OLETF rats.
共轭脂肪酸是具有共轭双键的多不饱和脂肪酸的位置异构体和几何异构体的统称，因其潜在的有益生物学效应而备受关注。在本研究中，在肥胖、高脂血症的大冢长-埃文斯-德岛肥胖（OLETF）大鼠中研究了富含石榴酸（9顺式，11反式，13顺式-共轭亚麻酸；9c，11t，13c-CLNA）的石榴籽油对脂质代谢的饮食影响。经过2周的喂养期，与它们的亲代LETO大鼠相比，OLETF大鼠出现了肥胖和高脂血症。在OLETF大鼠中，与补充10%红花油的饮食（对照饮食）相比，补充9%红花油和1%石榴籽油的饮食（9c，11t，13c-CLNA饮食）对腹部白色脂肪组织重量和血清脂质水平没有影响。然而，9c，11t，13c-CLNA饮食使OLETF大鼠肝脏中积累的三酰甘油显著降低。9c，11t，13c-CLNA饮食未改变与脂肪酸合成和脂肪酸β-氧化相关的肝脏酶活性。肥胖、高脂血症的OLETF大鼠血清三酰甘油中作为脂肪酸主要储存形式的单不饱和脂肪酸（MUFA）水平明显高于瘦的LETO大鼠。此外，9c，11t，13c-CLNA饮食显著降低了OLETF大鼠的MUFA水平。这是第一项表明9c，11t，13c-CLNA在体内抑制Δ-9去饱和作用的研究，并且我们认为9c，11t，13c-CLNA饮食减轻肝脏三酰甘油积累至少部分归因于对OLETF大鼠Δ-9去饱和作用的抑制。
