Wild rice (Zizania palustris L.) prevents atherogenesis in LDL receptor knockout mice

Abstract

Objectives: Dietary modifications including healthy eating constitute one of the first line strategies for prevention and treatment of cardiovascular disease (CVD) risk factors including high cholesterol and atherosclerosis. The purpose of the present study was to investigate the potential cardiovascular benefits of wild rice in male and female LDL-receptor-deficient (LDLr-KO) mice.

Methods: Wild rice was used to create a semi-synthetic diet containing approximately 60% of total energy from carbohydrate. Two other experimental diets were similar in macronutrient composition, but containing either white rice or commercial carbohydrate sources. All diets were supplemented with 0.06% (w/w) dietary cholesterol. The mice were divided into six experimental groups and fed with these diets over 24 weeks.

Results: Consumption of wild rice significantly reduced the size and severity of atherosclerotic lesions in the aortic roots of male and female mice by 71 and 61% respectively, compared to the control group of the same gender. This effect was associated with significant reductions of plasma cholesterol levels by 15 and 40%, low density lipoprotein (LDL) levels by 12 and 42%, and very low density lipoprotein (VLDL) levels by 35 and 75% respectively, in male and female mice compared to the control group of the same gender. Increased fecal cholesterol excretion of up to 34% was also noted, compared to the control group of the same gender. However, the antiatherogenic effect of wild rice was not associated with increased superoxide dismutase (SOD) and catalase (CAT) activities.

Conclusion: Current data suggest that cholesterol-lowering effects of wild rice may be the main factor for the prevention of atherogenesis in LDLr-KO mice. Additional studies are needed to understand the mechanism of action.

Keywords: Atherogenesis; LDL–receptor–deficient mice (LDLr-KO mice); Plasma cholesterol; White rice; Wild rice.