Location: Arkansas Children's Nutrition CenterTitle: Dietary rice protein isolate attenuates atherosclerosis in apoE-deficient mice by upregulating antioxidant enzymes Author
Submitted to: Atherosclerosis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/13/2010
Publication Date: 9/3/2010
Citation: Burris, R.L., Xie, C., Thampi, P., Wu, X., Melnyk, S., Nagarajan, S. 2010. Dietary rice protein isolate attenuates atherosclerosis in apoE-deficient mice by upregulating antioxidant enzymes. Atherosclerosis. 212(1):107-115. Interpretive Summary: Consumption of proper nutrition can prevent chronic diseases such as heart disease and cancer. A heart attack caused by thickening of the arteries is also known as atherosclerosis. Asians have a lower rate of heart disease than the Westerners. Rice is one of the main foods in the Asian population. Therefore, the decreased rate of heart disease may be due to their dietary consumption of rice. In this study, we examined the effect of eating rice on reducing atherosclerosis. This was tested using a mouse model. Consumption of rice reduced the size of atherosclerotic lesions in the arteries. Our findings suggest that consuming rice diets decrease the start of heart disease. Future studies will search for how eating rice is working to prevent atherosclerosis in developing animals.
Technical Abstract: Rice-based diets may have been reported to protect against the development of atherosclerosis; however, the underlying mechanism(s) for this protection remains unknown. In this report, the mechanism(s) contributing to the atheroprotective effects of rice-based diet was addressed using the apolipoprotein E knockout (apoE-/-) mice fed rice protein isolate (RPI) or casein (CAS). Reduced atherosclerotic lesions were observed in aortic sinus and enface analyses of the descending aorta in RPI-fed apoE-/- mice compared with CAS-fed mice. Plasma total- and HDL-cholesterol levels were not different amongst the two groups, suggesting alternative mechanism(s) could have contributed to the atheroprotective effect of rice-based diets. Plasma oxLDL and anti-oxLDL IgG levels were significantly decreased in RPI-fed compared to CAS-fed animals. Plasma and aortic tissue GSH levels and GSH:GSSG ratio were higher in RPI-fed mice compared to CAS-fed group. Interestingly, RPI feeding increased mRNA and protein expression of superoxide dismutase, and mRNA expression of catalase, glutathione peroxidase and glutathione reductase, key antioxidant enzymes implicated inhibiting oxidative stress leading to atherosclerosis. In conclusion, these findings suggest that the reduction in atherosclerotic lesions observed in mice fed the rice-based diet is mediated in part by inhibiting oxidative stress and subsequent oxLDL generation that could result in reduced foam cell formation, an early event during atherogenesis.