Effects of casein, sweet white lupin and sweet yellow lupin diet on cholesterol metabolism in rats

• Published in: Journal of the science of food and agriculture Vol. 76; no. 2; pp. 303 - 309
• Main Authors: Chango, Abalo, Villaume, Christian, Bau, Hwei Ming, Schwertz, Annie, Nicolas, Jean-Pierre, Mejean, Luc
• Format: Journal Article
• Language: English
• Published: London John Wiley & Sons, Ltd 01.02.1998; Wiley; Published for the Society of Chemical Industry by Elsevier Applied Science
• Subjects: amino acids; Biological and medical sciences; cholesterol; dietary proteins; Feeding. Feeding behavior; fibre; Fundamental and applied biological sciences. Psychology; glucagon; insulin; lupin; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Pancreatic hormone; Seeds; Glucagon; Rat; Secretion; Rodentia; Lipids; Lupin; Metabolism; Insulin; Cholesterol; Protein; Feeding; Vertebrata; Mammalia; Casein; Diet; Dietary fiber; Comparative study
• ISSN: 0022-5142; 1097-0010
• DOI: 10.1002/(SICI)1097-0010(199802)76:2<303::AID-JSFA961>3.0.CO;2-#

The effect of lupin seed protein on rat cholesterol metabolism has been studied with diets high in fat (20% by weight) and containing cholesterol (1%). The proteins used were characterised by their lysine/arginine ratios (sweet white lupin (SWL) 0·5; sweet yellow lupin (SYL) 0·4; and casein 1·8), because the lysine/arginine ratio is one of the parameters suspected to decrease or increase plasma cholesterol depending on the ratio; the diets were also characterised by their total fibre content (casein diet 5%; SWL 22%; SYL 17%) because chronic fibre intake could improve glucose tolerance and modify glucoregulatory hormone levels. Methionine content of diets was balanced. Differences among the total serum cholesterol levels of rat groups fed these diets for 28 days were not significant. But, compared to the casein diet, both lupin diets increased plasma glucagon levels and faeces. Compared to casein and SYL diets, the SWL diet significantly decreased plasma triglyceride levels and the insulin/glucagon ratio, as well as unesterified liver cholesterol and plasma LDL triglycerides levels. The SYL diet significantly increased plasma glucose and insulin, as well as liver total cholesterol compared to the casein and SWL diets. The total fibre content of the diets could indirectly modulate the effect related to the insulin/glucagon ratio on cholesterol metabolism and explain the differences observed between the SWL and SYL diets. © 1998 SCI.