Ling W H, Jones P J
Division of Human Nutrition, University of British Columbia, Vancouver, Canada.
Atherosclerosis. 1995 Dec;118(2):319-31. doi: 10.1016/0021-9150(95)05624-6.
To investigate the action and mechanism of a dietary phytosterol mixture naturally containing sitostanol, derived from tall-oil, on circulating cholesterol and lipoprotein levels, five groups of rats were fed a control elemental diet (group 1), a control elemental diet with 1% cholesterol alone (group 2) or with sitostanol mixtures or a sitostanol-free mixture supplemented at 0.2% (group 3), 0.5% (group 4) or 1% (group 5) of dietary levels. One per cent supplementation of sitostanol (21%) compared with sitostanol-free mixtures decreased (P < 0.02) total serum cholesterol. Dietary sitostanol (16% or 21%) mixture at 1% dietary levels decreased (P < 0.05) low density lipoprotein (LDL) cholesterol and increased (P < 0.05) high density lipoprotein (HDL) cholesterol levels. The decrease of LDL and increase of HDL cholesterol were correlated (P < 0.01) with the level of sitostanol mixture in the diet. Consumption of the sitostanol-containing mixture (1% dietary levels) caused a compensatory increase in cholesterol synthesis as indicated by elevated (P < 0.05) lathosterol/ cholesterol ratios in plasma and hepatic cholesterol fractional synthesis rate (FSR) (P < 0.02). Both sitostanol and sitostanol-free mixtures at 0.5% or 1% dietary intake levels increased plasma campesterol and beta-sitosterol levels, while plasma sitostanol levels were negligible. The absence of sitostanol in plasma and the increase in cholesterol synthesis induced by dietary sitostanol mixtures in addition to elevation of plasma campesterol and beta-sitosterol by sitostanol or sitostanol-free mixtures suggest that sitostanol mixtures effectively modify circulating lipoprotein cholesterol concentrations at the level of the intestine, rather than internally at the level of cholesterogenesis.
为研究一种天然含有谷甾烷醇的膳食植物甾醇混合物（来源于妥尔油）对循环胆固醇和脂蛋白水平的作用及机制，将五组大鼠分别喂食对照元素饮食（第1组）、仅含1%胆固醇的对照元素饮食（第2组），或添加0.2%（第3组）、0.5%（第4组）或1%（第5组）膳食水平的谷甾烷醇混合物或不含谷甾烷醇的混合物。与不含谷甾烷醇的混合物相比，添加1%的谷甾烷醇（21%）可降低（P<0.02）总血清胆固醇。膳食水平为1%时，含16%或21%谷甾烷醇的混合物可降低（P<0.05）低密度脂蛋白（LDL）胆固醇，并升高（P<0.05）高密度脂蛋白（HDL）胆固醇水平。LDL的降低和HDL胆固醇的升高与饮食中谷甾烷醇混合物的水平相关（P<0.01）。如血浆中羊毛甾醇/胆固醇比值升高（P<0.05）和肝脏胆固醇分数合成率（FSR）升高（P<0.02）所示，食用含谷甾烷醇的混合物（膳食水平为1%）会导致胆固醇合成的代偿性增加。膳食摄入量为0.5%或1%时，谷甾烷醇和不含谷甾烷醇的混合物均可提高血浆菜油甾醇和β-谷甾醇水平，而血浆谷甾烷醇水平可忽略不计。血浆中不存在谷甾烷醇，以及膳食谷甾烷醇混合物诱导胆固醇合成增加，此外，谷甾烷醇或不含谷甾烷醇的混合物可提高血浆菜油甾醇和β-谷甾醇水平，这表明谷甾烷醇混合物在肠道水平而非胆固醇生成的内部水平有效改变循环脂蛋白胆固醇浓度。
