Protective effects of blueberries (BB) against atherosclerosis and potential underlying mechanisms in reducing oxidative stress were examined in apoE-deficient (apoE(-/-)) mice. ApoE(-/-) mice were fed an AIN-93G diet (CD) or CD formulated to contain 1% freeze-dried whole BB for 20 wk. The mean lesion area for apoE(-/-) mice fed BB was reduced by 39% (P < 0.001) in the aorta sinus and 58% (P < 0.001) in the descending aorta compared with CD-fed mice. These atheroprotective effects were independent of the serum lipid profile or total antioxidant capacity (as measured by oxygen radical absorbance capacity). The concentration of a biomarker of lipid peroxidation, F(2)-isoprostane, was lower in liver of BB-fed mice (P < 0.05). Genes analyzed by RT-PCR array showed that 4 major antioxidant enzymes in aorta [superoxide dismutase (SOD) 1, SOD2, glutathione reductase (GSR), and thioredoxin reductase 1] were upregulated in BB-fed mice. Enzyme activities of SOD and GSR were greater (P < 0.05) in liver and/or serum of BB-fed mice than those of CD-fed mice. In addition, serum paraoxonase 1 activity in serum of BB-fed mice was also greater than that of CD-fed mice (P < 0.05) at the end of the study. These results suggest a protective effectiveness of BB against atherosclerosis in this apoE(-/-) mouse model. The potential mechanisms may involve reduction in oxidative stress by both inhibition of lipid peroxidation and enhancement of antioxidant defense.
Xianli Wu, Jie Kang, Chenghui Xie, Ramona Burris, Matthew E. Ferguson, Thomas M. Badger, and Shanmugam Nagarajan. Dietary Blueberries Attenuate Atherosclerosis in Apolipoprotein E-Deficient Mice by Upregulating Antioxidant Enzyme Expression J. Nutr. 2010 September USDA Arkansas Children's Nutrition Center, University of Arkansas for Medical Sciences, Little Rock, AR 72202, USA