A Lutein-enriched diet prevents cholesterol accumulation and decreases oxidized LDL and inflammatory cytokines in the aorta of guinea pigs

Abstract

Lutein has been shown to be protective against age-related macular degeneration; however, the antiinflammatory and antioxidant effects of this carotenoid in aortas are less known. Guinea pigs were fed a hypercholesterolemic diet (0.25 g cholesterol/100 g) and randomly allocated to a control group (n = 9) or a lutein group (n = 10) (0.1 g/100 g lutein) and fed the experimental diets for 12 wk. Plasma LDL cholesterol and TG did not differ between groups; however, the lutein group had lower concentrations of medium size LDL (P < 0.05). As expected, guinea pigs from the lutein group had higher concentrations of plasma and liver lutein than those from the control group (P < 0.0001). Aortic cholesterol and malondialdehyde concentrations were lower in the lutein group (9.6 ± 2.8 mmol/g and 1.69 ± 1.35 nmol/mg protein) compared to the control group (15.5 ± 2.3 mmol/g and 2.98 ± 1.45 nmol/mg protein) (P < 0.05). Hematoxilin and eosin staining indicated that aortas from the control group presented focal intimal thickening, whereas either less thickness or no visible thickness was present in aortas from the lutein group. Oxidized LDL (oxLDL) was lower both in plasma and aorta in the lutein group compared to the control group (P < 0.001). Aortic cytokines were also lower in the lutein group (P < 0.05). Plasma lutein and oxLDL (r = -0.79; P < 0.0001) and plasma lutein and aortic oxLDL (r = -0.64; P < 0.0001) were negatively correlated. These data suggest that lutein exerts potent antioxidant and antiinflammatory effects in aortic tissue that may protect against development of atherosclerosis in guinea pigs. © 2011 American Society for Nutrition.