Effects of the whole seed and a protein isolate of faba bean (Vicia faba) on the cholesterol metabolism of hypercholesterolaemic rats.
The aim of the present work was to analyse the hypocholesterolaemic efficiency of a Vicia faba-protein isolate in relation to the intact legume. In addition, the mechanisms underlying the effects of this isolate were investigated. Hypercholesterolaemic rats were divided into three groups and fed high-fat diets rich in cholesterol-containing casein, whole seeds of Vicia faba or the protein isolate of faba beans as protein source, for 2 weeks ad libitum. The protein isolate was prepared by isoelectric precipitation and spray dried. Analyses of serum, liver and faeces, as well as of the activity of hepatic 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase, were assessed by enzymatic methods. The rats fed on Vicia faba diets showed significantly lower body weights and energy intakes than rats fed on casein diets. The whole-seed diet induced a significant reduction in plasma triacylglycerol. Feeding rats on diets containing faba bean seeds, or the protein isolate, induced a significant decrease in plasma (LDL+VLDL)-cholesterol but not in HDL-cholesterol. Hepatic cholesterol and triacylglycerol were also reduced. The hypocholesterolaemic effects of Vicia faba were not the result of a reduction in cholesterol synthesis as assessed from HMG-CoA reductase activity, but the result of an increase in steroid faecal excretion. The faba bean-protein isolate obtained under our experimental conditions was useful in improving the metabolic alterations induced by feeding with a hypercholesterolaemic diet compared with casein. The effectiveness of the whole seeds was higher than that of the protein isolate.
Macarulla
M T
MT
Department of Nutrition and Food Science, University of País Vasco, Paseo de la Universidad 7, 01006 Vitoria, Spain. knpmaarm@vc.ehu.es
Medina
C
C
De Diego
M A
MA
Chávarri
M
M
Zulet
M A
MA
Martínez
J A
JA
Nöel-Suberville
C
C
Higueret
P
P
Portillo
M P
MP
D000704:Analysis of Variance; D000818:Animals; D002364:Caseins / Q000378:metabolism; D002784:Cholesterol / Q000378:metabolism*; D004044:Dietary Proteins / Q000008:administration & dosage*; D007887:Fabaceae; D005243:Feces / Q000737:chemistry; D006903:Hydroxymethylglutaryl CoA Reductases / Q000378:metabolism; D006937:Hypercholesterolemia / Q000378:metabolism*; D008055:Lipids / Q000032:analysis; D008099:Liver / Q000737:chemistry / Q000378:metabolism*; D008297:Male; D010946:Plants, Medicinal; D051381:Rats; D017208:Rats, Wistar; D012639:Seeds; D014280:Triglycerides / Q000097:blood
D002364:Caseins; D004044:Dietary Proteins; D008055:Lipids; D014280:Triglycerides; D002784:Cholesterol; D006903:Hydroxymethylglutaryl CoA Reductases