Antioxidant And Anti-Inflammatory Effects Of Lutein In Guinea Pigs Fed With A High Cholestorol Diet

The main objective of this study was to evaluate the protective effects of lutein on atherosclerosis, liver injury and eye in guinea pigs fed with a hypercholesterolemic diet. Guinea pigs fed a high cholesterol diet (0.25g cholesterol/100g of diet) were randomly assigned to the control group (n = 9) and the lutein group (n = 10) (0.1 g lutein/100 g of diet). ^ In the first study, lutein had no effect on plasma lipid profiles; however, it lowered circulating atherogenic LDL particles. In addition, dietary lowered oxidized LDL (oxLDL) concentrations in both plasma and aorta and decreased cholesterol accumulation, malondialdehyde (MDA), pro-inflammatory cytokines in the aorta. Further hematoxylin and eosin (H&E) staining indicated that the aortas from most of the lutein fed guinea pigs were devoid of intimal plaques. Whereas, those from the control group showed thickened intimal layer with foam cell infiltration.^ In the second study, guinea pigs fed lutein accumulated the carotenoid in eyes and had lower levels of MDA and pro-inflammatory cytokines. Furthermore, lutein treatment protected against degenerative changes in the liver of guinea pigs fed a high cholesterol diet by reducing hepatic free cholesterol, decreasing lipid peroxidation and attenuating the inflammatory responses. The attenuated inflammatory responses in the liver were associated with the decreased nuclear factor-kappaB (NF-κB) p65 DNA binding activity. However, there were no differences in alanine aminotransferase (ALT) and aspartate aminotransferase (AST) concentrations between groups, indicators of liver injury.^ In conclusion, the results from both studies indicate that lutein can accumulate in the eye of guinea pigs and exert antioxidant and anti-inflammatory effects. Furthermore, it protects against the development of atherosclerosis and liver injury by reducing cholesterol accumulation in the aorta and decreasing lipid peroxidation and attenuating the inflammatory state both in aorta and liver.