Turley S D, Dietschy J M
Department of Internal Medicine, University of Texas Southwestern Medical Center at Dallas 75235-8887, USA.
Biochim Biophys Acta. 1995 Mar 16;1255(2):177-84. doi: 10.1016/0005-2760(94)00216-l.
Psyllium hydrophillic mucilloid (psyllium) is a soluble fiber that significantly lowers plasma low-density lipoprotein (LDL)-cholesterol levels in humans and experimental animals. These studies were designed to determine whether this action is the result of a reduction in LDL-cholesterol production, an increase in receptor-mediated LDL clearance by the tissues, or a combination of these mechanisms. Adult male Golden Syrian hamsters were fed ad libitum for 30 days a cereal-based diet containing added cholesterol (0.1%) and hydrogenated coconut oil (10%), as well as either microcrystalline cellulose (Avicel) (7.5%) or psyllium (7.5%). In contrast to their Avicel-fed controls, the hamsters given psyllium had markedly lower plasma total (122.1 +/- 4.1 vs. 399.4 +/- 39.4 mg/dl) and LDL-cholesterol (46.0 +/- 2.2 vs. 143.5 +/- 12.0 mg/dl) levels. Psyllium feeding also prevented both the dramatic increase in hepatic total cholesterol levels (2.6 +/- 0.1 vs. 16.6 +/- 1.1 mg/g), and the suppression of hepatic cholesterol synthesis (165.1 +/- 27.1 vs. 26.1 +/- 1.2 nmol/h per g) that occurred in the animals given Avicel. Compared to their controls, the psyllium-fed animals also manifested a 44% lower rate of LDL-cholesterol production (167.6 +/- 8.1 vs. 300.2 +/- 16.0 micrograms/h per 100 g bw), and a 2.2-fold higher rate of hepatic LDL clearance (50.1 +/- 2.3 vs. 22.6 +/- 2.1 microliters/h per g). When expressed as a percentage of corresponding values obtained for hamsters fed the basal diet without any additions, the relative rate of LDL-cholesterol production was 175 +/- 10% and 99 +/- 4% for the Avicel- and psyllium-fed groups, respectively. It was similarly determined that the level of whole animal relative LDL receptor activity was marginally higher in the hamsters given psyllium (55.9 +/- 1.4%) than in those fed Avicel (47.5 +/- 3.3%). Thus, it was concluded that while the LDL-cholesterol lowering action of psyllium in the hamster is mediated through two mechanisms, the major effect is exerted at the level of LDL-cholesterol production.
亲水洋车前子胶（洋车前子）是一种可溶性纤维，可显著降低人类和实验动物的血浆低密度脂蛋白（LDL）胆固醇水平。这些研究旨在确定这种作用是由于LDL胆固醇生成减少、组织中受体介导的LDL清除增加，还是这些机制的综合作用。成年雄性金黄叙利亚仓鼠随意进食含添加胆固醇（0.1%）和氢化椰子油（10%）的谷类饮食30天，同时分别添加微晶纤维素（微晶纤维素）（7.5%）或洋车前子（7.5%）。与喂食微晶纤维素的对照组相比，喂食洋车前子的仓鼠血浆总胆固醇（122.1±4.1对399.4±39.4mg/dl）和LDL胆固醇（46.0±2.2对143.5±12.0mg/dl）水平明显更低。喂食洋车前子还可防止肝脏总胆固醇水平急剧升高（2.6±0.1对16.6±1.1mg/g），以及喂食微晶纤维素的动物出现的肝脏胆固醇合成抑制（165.1±27.1对26.1±1.2nmol/h每克）。与对照组相比，喂食洋车前子的动物LDL胆固醇生成率也降低了44%（167.6±8.1对300.2±16.0微克/小时每100克体重），肝脏LDL清除率提高了2.2倍（50.1±2.3对22.6±2.1微升/小时每克）。以喂食无任何添加物的基础饮食的仓鼠相应值的百分比表示时，微晶纤维素组和洋车前子组的LDL胆固醇相对生成率分别为175±10%和99±4%。同样确定，喂食洋车前子仓鼠的全动物相对LDL受体活性水平（55.9±1.4%）略高于喂食微晶纤维素的仓鼠（47.5±3.3%）。因此，得出结论，虽然洋车前子在仓鼠中降低LDL胆固醇的作用是通过两种机制介导的，但主要作用是在LDL胆固醇生成水平发挥的。
