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) (0.01 g/100 g
lutein) [corrected] 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.