title: Red algal cellular biomass lowers circulating cholesterol concentrations in Syrian golden hamsters consuming hypercholesterolaemic diets.
abstract: Preliminary evidence suggests that consumption of Porphyridium cruentum (PC) biomass results in hypocholesterolaemic effects; however, mechanisms responsible have not been elucidated. The aim of the present study was to determine whether PC biomass lowers circulating cholesterol concentrations, dose dependently, in hamsters fed hypercholesterolaemic diets for 28 d and determine whether cholesterol biosynthesis is affected. Biomass added to diets at 2.5, 5 and 10% resulted in 14, 38 and 53% reductions (P < 0.001) in total plasma cholesterol, respectively, compared with a control diet. Similarly, non-HDL-cholesterol concentrations in the 5 and 10% PC groups were reduced (P < 0.001) 28 and 45%, respectively, v. controls. These effects were unrelated to cholesterol fractional synthesis rate (FSR), as this did not differ between either treatment or control animals. PC consumption had no effect on food intake, plasma glucose concentrations or energy expenditure, but percentage of body fat was lower (P < 0.001) in the 5 and 10% PC groups compared with controls. These data show that PC reduces total plasma cholesterol and non-HDL-cholesterol when incorporated into the diet at levels as low as 2.5%. The mechanism of action for this reduction may be related to increased excretion since food intakes and cholesterol FSR were not reduced in the animals receiving the PC. In conclusion, the use of PC biomass reduces circulating cholesterol, dose dependently, in hypercholesterolaemic hamsters but not via reductions in cholesterol FSR. There is potential for the use of this biomass as a functional ingredient to aid in the management of blood cholesterol concentrations.
authors.affiliation: Richardson Centre for Functional Foods and Nutraceuticals, University of Manitoba, 196 Innovation Drive, Winnipeg, MB, Canada R3T 6C5.
authors.forename: Scott V
authors.initials: SV
authors.lastname: Harding
authors.forename: Hai Lin
authors.initials: HL
authors.lastname: Zhao
authors.forename: Christopher P F
authors.initials: CP
authors.lastname: Marinangeli
authors.forename: Anthony G
authors.initials: AG
authors.lastname: Day
authors.forename: Harrison F
authors.initials: HF
authors.lastname: Dillon
authors.forename: Deepak
authors.initials: D
authors.lastname: Jain
authors.forename: Peter J H
authors.initials: PJ
authors.lastname: Jones
mesh_terms: D000818:Animals; D018533:Biomass; D001786:Blood Glucose / Q000378:metabolism; D001823:Body Composition; D002784:Cholesterol / Q000096:biosynthesis / Q000097:blood; D006224:Cricetinae; D004032:Diet / Q000009:adverse effects; D004195:Disease Models, Animal; D004435:Eating; D004734:Energy Metabolism; D006937:Hypercholesterolemia / Q000097:blood / Q000209:etiology / Q000517:prevention & control*; D008055:Lipids / Q000097:blood; D008647:Mesocricetus; D044665:Porphyridium; D015430:Weight Gain
chemical_list: D001786:Blood Glucose; D008055:Lipids; D002784:Cholesterol