Anti-Fatty Liver Activity and its Mechanism of Non-Methylene-Interrupted Fatty Acid

我们研究了香榧油中富含的非亚甲基中断的多不饱和脂肪酸-二十碳三烯酸（均为顺式-5，11，14-二十碳三烯酸）对大鼠脂质代谢的影响。用玉米油或香榧（Torreya nucifera）油使肥胖大鼠（OLETF大鼠）生长2周。饲喂香榧油的肥胖大鼠血清和肝脏三酰甘油和血清胆固醇水平较低。此外，大鼠用含5%酒精的饲料与香榧油、玉米或大豆油一起生长6周。喂食香榧油的大鼠血清三酰甘油和胆固醇水平较低。值得注意的是，饲喂香榧的大鼠表现出较低的血清GPT和GOT活性。为了解香榧油降低血浆和肝脏三酰甘油的作用机制，采用尿素加合法和脂肪酶酯化法从香榧籽油中分离得到了西阿东酸。Sprague-Dawley（SD）雄性大鼠喂食含有5%和10%基于玉米油的二十碳四烯酸的实验饲料2周。喂饲西阿东酸的大鼠血清和肝脏三酰甘油水平较低。大量的雪阿东酸被检测到的三酰甘油和磷脂在大鼠的血清和肝脏喂养的雪阿东酸。我们还使用HepG 2研究了二十碳四烯酸和皮诺敛酸（均为顺式-5，9，12-十八碳三烯酸，为非亚甲基间断脂肪酸）对人肝癌细胞生长和脂质代谢的影响。当浓度超过50 μ M时，无论是石松烯酸还是皮诺敛酸都能抑制HepG 2细胞的生长。然而，它们增加了HepG 2中的脂质含量。从这些结果可以看出，二十碳四烯酸可以改善大鼠的脂质代谢，抑制脂肪肝。

We investigated effects of non-methylene-interrupted polyunsaturated fatty acid, sciadonic acid (all cis-5,11,14-eicosatrienoic acid) rich in torreya oil on the lipid metabolism in rat. Fatty rats (OLETF rats) were grown with corn oil or torreya (Torreya nucifera) oil for 2 weeks. Serum and liver triacylglycerol and serum cholesterol levels were lower in fatty rats fed torreya oil. Moreover, rats were grown with 5% alcohol-containing feeds together with torreya oil, corn or soybean oil for 6 weeks. Serum triacylglycerol and cholesterol levels were lower in rats fed torreya oil. It was interesting that rats fed torreya showed lower serum GPT and GOT activities. To know the mechanism of plasma and hepatic triacylglycerol-lowering effects of torreya oil, sciadonic acid was isolated from Japanese torreya seed oil by the combination of urea-adduct with lipase-esterification. Sprague-Dawley (SD) male rats fed the experimental diets containing 5% and 10% sciadonic acid based on corn oil for 2 weeks. Serum and liver triacylglycerol levels were lower in rats fed sciadonic acid. Considerable amounts of sciadonic acid were detected in triacylglycerol and phospholipid in both serum and liver of rats fed sciadonic acid. We also investigated the effects of sciadonic acid and pinolenic acid (all cis-5,9,12-octadecatrienoic acid as non-methylene-interrupted fatty acids on the growth and lipid metabolism of human hepatic cancer cell using HepG2. Both sciadonic and pinolenic acids inhibited the growth of HepG2 at more than 50uM. However, they increased lipid contents in HepG2. From these results, it was demonstrated that sciadonic acid could modify the lipid metabolism and suppress fatty liver in rats.