Bettzieche Anja, Brandsch Corinna, Weisse Kristin, Hirche Frank, Eder Klaus, Stangl Gabriele I
Institute of Agricultural and Nutritional Sciences, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany.
Br J Nutr. 2008 May;99(5):952-62. doi: 10.1017/S0007114507857266. Epub 2007 Dec 21.
To assess the effect of lupin protein on concentrations of lipids in plasma lipoproteins and liver and hepatic mRNA concentrations of genes involved in lipid metabolism, adult rats were fed egg albumin-based diets containing either lupin protein from Lupinus albus or casein (50 g/kg) supplemented (hypercholesterolaemic) or not (normolipaemic) with a cholesterol-cholate mixture for 20 d. Lupin protein compared with casein lowered the concentrations of TAG in liver (P < 0.01) and circulating VLDL + chylomicrons (P < 0.05) of hypercholesterolaemic rats, but not of normolipaemic rats. Hepatic mRNA concentrations of genes involved in fatty acid synthesis such as sterol regulatory element-binding protein-1c, glucose-6-phosphate dehydrogenase, fatty acid synthase, stearoyl-CoA desaturase-1 and acyl-CoA:glycerol-3-phosphate acyltransferase were lower and mRNA concentrations of lipoprotein lipase, hepatic lipase and apoA5 involved in TAG hydrolysis were higher in rats fed lupin protein than in rats fed casein. These effects were stronger in hypercholesterolaemic rats than in normolipaemic rats. Hypercholesterolaemic rats fed the lupin protein had higher liver cholesterol concentrations (P < 0.01) and lower levels of LDL-cholesterol (P < 0.05) than rats fed casein. No effect of lupin protein was observed on cholesterol concentration in VLDL + chylomicrons and HDL and hepatic mRNA concentrations of genes involved in cholesterol and bile acid metabolism. In conclusion, the present study shows that lupin protein has hypotriacylglycerolaemic action possibly via down regulation of fatty acid synthesis genes and up regulation of genes involved in TAG hydrolysis. Alterations in cholesterol metabolism could not be explained on the basis of mRNA data.
为评估羽扇豆蛋白对血浆脂蛋白中脂质浓度、肝脏以及参与脂质代谢的基因的肝脏mRNA浓度的影响，将成年大鼠喂食以卵清蛋白为基础的日粮，其中包含来自白羽扇豆的羽扇豆蛋白或酪蛋白（50 g/kg），并添加（高胆固醇血症）或不添加（正常血脂）胆固醇 - 胆酸盐混合物，持续20天。与酪蛋白相比，羽扇豆蛋白降低了高胆固醇血症大鼠肝脏中甘油三酯（TAG）的浓度（P < 0.01）以及循环中的极低密度脂蛋白（VLDL）+乳糜微粒（P < 0.05），但对正常血脂大鼠没有影响。与喂食酪蛋白的大鼠相比，喂食羽扇豆蛋白的大鼠中，参与脂肪酸合成的基因如固醇调节元件结合蛋白-1c、葡萄糖-6-磷酸脱氢酶、脂肪酸合酶、硬脂酰辅酶A去饱和酶-1和酰基辅酶A：甘油-3-磷酸酰基转移酶的肝脏mRNA浓度较低，而参与TAG水解的脂蛋白脂肪酶、肝脂肪酶和载脂蛋白A5的mRNA浓度较高。这些作用在高胆固醇血症大鼠中比在正常血脂大鼠中更强。喂食羽扇豆蛋白的高胆固醇血症大鼠比喂食酪蛋白的大鼠具有更高的肝脏胆固醇浓度（P < 0.01）和更低的低密度脂蛋白胆固醇水平（P < 0.05）。未观察到羽扇豆蛋白对VLDL +乳糜微粒和高密度脂蛋白（HDL）中的胆固醇浓度以及参与胆固醇和胆汁酸代谢的基因的肝脏mRNA浓度有影响。总之，本研究表明羽扇豆蛋白可能通过下调脂肪酸合成基因和上调参与TAG水解的基因而具有降甘油三酯作用。基于mRNA数据无法解释胆固醇代谢的改变。
