Egg yolk improves lipid profile, lipid peroxidation and retinal abnormalities in a murine model of genetic hypercholesterolemia.
Carotenoids are believed to inhibit oxidative stress. We investigated the protective effect of lutein and egg yolk supplementation on systemic and retinal alterations in apolipoprotein E-deficient (apoE-/-) mice, an experimental model of hypercholesterolemia and cardiovascular disease. Three-month-old wild-type and apoE-/- mice received one of the following: vehicle, lutein (0.09 mg/kg per day) or egg yolk (0.8 g/kg per day), by gastroesophageal cannula for 3 months. Total cholesterol (TC), triacylglycerol (TG) and lipid peroxidation (TBARS) were measured in plasma. TBARS levels were also determined in retinal homogenates. Ultrastructural morphology was analyzed by electron microscopy. ApoE-/- mice, with increased TC and TG concentrations, had higher systemic (P<.05) and retinal (P<.01) levels of lipid peroxidation than wild-type strains. Electron microscopy showed ultrastructural alterations (basal laminar deposits, open intercellular junctions, increased cytoplasmic vacuoles) in the retinas from apoE-/- mice. Egg yolk significantly reduced plasma TG (P<.05) and, without changes in TC, decreased plasma lipid peroxidation (P<.05). Lutein supplementation marginally affected the parameters. Less severe retinal ultrastructural alterations were observed in apoE-/- mice receiving either egg yolk or lutein. In the apoE-/- mouse model, egg yolk improved the lipid profile and reduced systemic lipid peroxidation (P<.05). While lutein and egg yolk did not seem to reduce retinal lipid peroxidation, a reduction in retinal ultrastructural alterations was observed.
Fernández-Robredo
Patricia
P
Department of Ophthalmology, Ophthalmology Research Laboratory, University Clinic, School of Medicine, University of Navarra, 31008 Pamplona, Spain.
Rodríguez
José Antonio
JA
Sádaba
Luis M
LM
Recalde
Sergio
S
García-Layana
Alfredo
A
D000818:Animals; D001057:Apolipoproteins E / Q000172:deficiency; D004195:Disease Models, Animal; D004530:Egg Yolk / Q000737:chemistry; D006937:Hypercholesterolemia / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D015227:Lipid Peroxidation; D008055:Lipids / Q000097:blood*; D014975:Lutein / Q000008:administration & dosage; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D046529:Microscopy, Electron, Transmission; D012160:Retina / Q000737:chemistry / Q000648:ultrastructure*; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis; D019108:Tight Junctions / Q000648:ultrastructure; D014617:Vacuoles / Q000648:ultrastructure
D001057:Apolipoproteins E; D008055:Lipids; D017392:Thiobarbituric Acid Reactive Substances; D014975:Lutein