Grain Sorghum Lipid Extract Reduces Cholesterol Absorption and Plasma Non-HDL Cholesterol Concentration in Hamsters
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Grain sorghum is a rich source of phytochemicals that could potentially benefit human health. In this study, male hamsters were fed AIN-93M diets supplemented with a hexane-extractable lipid fraction from grain sorghum whole kernels. The grain sorghum lipids (GSL) comprised 0.0, 0.5, 1.0, or 5.0% of the diet by weight. After 4 wk, dietary GSL significantly reduced plasma non-HDL cholesterol concentration in a dose-dependent manner with reductions of 18, 36, and 69% in hamsters fed 0.5, 1.0, and 5.0% GSL, respectively, compared with controls. Liver cholesteryl ester concentration was also significantly reduced in hamsters fed GSL. Plasma HDL cholesterol concentration was not altered (P > 0.05) by dietary treatment. Cholesterol absorption efficiency was significantly reduced by GSL in a dose-dependent manner. Cholesterol absorption was also directly correlated with plasma non-HDL cholesterol concentration (r = 0.97, P < 0.05), suggesting that dietary GSL lowers non-HDL cholesterol, at least in part, by inhibiting cholesterol absorption. TLC and GLC analyses of the GSL extract revealed the presence of plant sterols and policosanols at concentrations of 0.35 and 8.0 g/100 g GSL, respectively. Although plant sterols reduce cholesterol absorption, policosanols may inhibit endogenous cholesterol synthesis. The data suggest that these components of GSL extract may work collectively in lowering plasma and liver cholesterol concentrations. Our findings further indicate that grain sorghum contains beneficial components that could be used as food ingredients or dietary supplements to manage cholesterol levels in humans.