Dietary carotenoids of corn fractions do not seem to affect the development of atherosclerotic lesions in LDL-r-KO mice
K. MASISI (1), K. Le (2), N. Ghazzawi (3), T. Paestch (4), T. Beta (1), M. Moghadasian (4) (1) Department of Food Science, University of manitoba, Winnipeg, MB, Canada; (2) Canadian Centre for Agri-Food Research in Health and Medicine, University of Manitoba, Winnipeg, Manitoba, Canada, Winnipeg, MB, Canada; (3) Department of Human Nutritional Sciences, University of Manitoba, Winnippeg, MB, Canada; (4) Department of Human Nutritional Sciences, University of Manitoba, Winnipeg, MB, Canada.
Carotenoid compounds are consistently shown to have potent antioxidant properties that play an essential role in preventing oxidative stress-induced diseases, like cardiovascular disease. Our previous study showed differential antioxidant potential of carotenoid extracts of hand-separated aleurone, germ and endosperm fractions of corn > wheat > barley in biochemical and <i>in vitro </i>models. In this study, protective effects of corn fractions (aleurone, endosperm and germ) against atherosclerosis and potential underlying mechanism in reducing oxidative stress were examined in low density lipoprotein receptor knockout (LDL-r-KO) mice. Four groups of male LDL-r-KO mice (n=32; 8 mice/group) were fed for 10 weeks with the experimental diets supplemented with (3 treated groups) or without (1 control group) 5% (w/w) of each of the hand-separated corn fractions. All diets were supplemented with 0.06% (w/w) dietary cholesterol. Blood samples, hearts, and livers were collected and used for biochemical and histological examination. Consumption of aleurone and germ fractions significantly reduced the size and severity of atherosclerotic lesions in the aortic roots (<i>P</i>=0.003) and improved the antioxidative status when compared to those in the control group. Incorporation of corn fractions boosted the total carotenoid contents (TCC (<i>P</i>=0.06), lutein (<i>P</i>=0.004) and zeaxanthin (<i>P</i>=0.002)) of the diets. However, the concentrations of TCC, lutein and zeaxanthin were comparable in the liver and plasma samples among all groups. Therefore, the antiatherogenic effects of germ and aleurone fractions might be due to synergistic effect of phytochemicals in these fractions. Additional studies are necessary to understand the exact mechanism of action.
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