Lupin protein influences the expression of hepatic genes involved in fatty acid synthesis and triacylglycerol hydrolysis of adult rats

• Published in: British journal of nutrition Vol. 99; no. 5; pp. 952 - 962
• Main Authors: Bettzieche, Anja, Brandsch, Corinna, Weiße, Kristin, Hirche, Frank, Eder, Klaus, Stangl, Gabriele I.
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01.05.2008
• Subjects: animal models; Animals; Bile Acids and Salts - metabolism; Biological and medical sciences; biosynthesis; Body Weight - drug effects; casein; Cholesterol; Cholesterol - metabolism; Dietary Proteins - pharmacology; Eating - drug effects; fatty acid synthesis; Fatty acids; Fatty Acids - biosynthesis; Fatty Acids - genetics; Feeding. Feeding behavior; Fundamental and applied biological sciences. Psychology; gene expression; Gene Expression Regulation - drug effects; genes; Genetics; Hepatic gene expression; Hydrolysis; Hydrolysis - drug effects; lipid metabolism; Lipid Metabolism - drug effects; Lipid Metabolism - genetics; Lipids; liver; Liver - anatomy & histology; Liver - metabolism; Liver lipids; Lupin protein; Lupinus - chemistry; Lupinus albus; Male; messenger RNA; Metabolism; Nutrition; Organ Size - drug effects; plant proteins; Plant Proteins - pharmacology; Plasma lipoproteins; Proteins; Rats; Rats, Sprague-Dawley; RNA, Messenger - genetics; triacylglycerols; Triglycerides - metabolism; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Rats; Lupin protein; Hepatic gene expression; Plasma lipoproteins; Liver lipids; Human; Rat; Digestive system; Liver; Rodentia; Lipids; Lupin; Biosynthesis; Lipoprotein; Gene expression; Fatty acids; Protein; Blood plasma; Hydrolysis; Vertebrata; Mammalia; Triacylglycerol; Animal; Adult; Lupin protein: Liver lipids: Plasma lipoproteins: Hepatic gene expression: Rats
• ISSN: 0007-1145; 1475-2662
• DOI: 10.1017/S0007114507857266

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.