Corn husk oil lowers plasma LDL cholesterol concentrations by decreasing cholesterol absorption and altering hepatic cholesterol metabolism in guinea pigs

To evaluate some of the mechanisms involved in the plasma cholesterol lowering of sitostanol (SI), male Hartley guinea pigs were fed diets containing cholesterol (0.25 g/100 g) and four doses of SI: either 0 (control), 0.75, 1.5 or 2.25 g/100 g. In addition a negative control (-C) group with dietary cholesterol (0.04 g/100 g) was included. Corn oil was used as the source of fat and the contribution of fat energy was 35 %. Plasma total cholesterol was 43, 49 and 53 % (P<0.0001) lower after SI intake compared to the control. Plasma LDL concentrations were 47, 53 and 61 % lower with increasing doses of SI. In addition, intake of SI resulted in 26–42 % lower hepatic total cholesterol. Hepatic esterified cholesterol and triacylglycerols were 32–60 % and 55–61 % lower after SI intake. SI intake resulted in favourable plasma and hepatic cholesterol concentrations similar to those in guinea pigs fed low levels of dietary cholesterol (-C). The LDL obtained from the control group had a higher number of molecules of free and esterified cholesterol than the SI groups. SI intake resulted in 69–71 % higher cholesterol excretion compared to the control. SI treatment enhanced the total faecal neutral sterol excretion by 54–58 % compared to control and by 70–76 % compared to the (-C) group. These results suggest that SI might have its hypocholesterolaemic effect by reducing cholesterol absorption, which results in lower concentration of cholesterol in liver. This reduction in hepatic cholesterol might possibly alter hepatic cholesterol metabolism and affect lipoprotein concentration and composition.

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Corn Fiber Oil Lowers Plasma Cholesterol by Altering Hepatic Cholesterol Metabolism and Up-Regulating LDL Receptors in Guinea Pigs

Journal of Nutrition ◽

10.1093/jn/132.3.335 ◽

2002 ◽

Vol 132 (3) ◽

pp. 335-340 ◽

Cited By ~ 17

Author(s):

Tripurasundari Ramjiganesh ◽

Suheeta Roy ◽

Hedley C. Freake ◽

Jonathan C. McIntyre ◽

Maria Luz Fernandez

Keyword(s):

Guinea Pigs ◽

Cholesterol Metabolism ◽

Plasma Cholesterol ◽

Corn Fiber ◽

Hepatic Cholesterol ◽

Ldl Receptors ◽

Fiber Oil ◽

Corn Fiber Oil

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Natural Dietary Phytosterols

Journal of AOAC International ◽

10.5740/jaoacint.sgeracette ◽

2015 ◽

Vol 98 (3) ◽

pp. 679-684 ◽

Cited By ~ 26

Author(s):

Susan B Racette ◽

Xiaobo Lin ◽

Lina Ma ◽

Richard E Ostlund, Jr

Keyword(s):

Ldl Cholesterol ◽

Cholesterol Metabolism ◽

Disease Risk ◽

Cholesterol Biosynthesis ◽

Cholesterol Absorption ◽

Absorption Efficiency ◽

Whole Body ◽

Natural Diet ◽

Cholesterol Excretion ◽

Heart Disease Risk

Abstract Most clinical phytosterol studies are performed by adding purified supplements to smaller phytosterol amounts present in the natural diet. However, natural dietary phytosterols themselves may also have important effects on cholesterol metabolism. Epidemiological work using food frequency questionnaires to estimate dietary intake suggest that extremes of normal consumption may be associated with 3–14% changes in LDL cholesterol. Standardized food databases do not have enough phytosterol values to allow calculation of phytosterol intake for individuals outside of specialized studies. Natural diets contain phytosterol amounts ranging from less than 60 mg/2000 kcal to over 500 mg/2000 kcal. Physiological studies in which whole body cholesterol metabolism is investigated show large effects of natural dietary phytosterols on cholesterol absorption efficiency, cholesterol biosynthesis and cholesterol excretion which exceed the magnitude of changes in LDL cholesterol. The dual effects of natural phytosterols on both LDL-C and whole body cholesterol metabolism need to be considered in relating them to potential protection from coronary heart disease risk.

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Resistant starch and cholestyramine have distinct effects on hepatic cholesterol metabolism in guinea pigs fed a hypercholesterolemic diet

Nutrition Research ◽

10.1016/s0271-5317(00)00170-6 ◽

2000 ◽

Vol 20 (6) ◽

pp. 837-849 ◽

Cited By ~ 21

Author(s):

Maria Luz Fernandez ◽

Suheeta Roy ◽

Marcela Vergara-Jimenez

Keyword(s):

Resistant Starch ◽

Guinea Pigs ◽

Cholesterol Metabolism ◽

Hepatic Cholesterol ◽

Hypercholesterolemic Diet

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Effect of esterified 4-desmethylsterols and -stanols or 4,4′-dimethylsterols on cholesterol and bile acid metabolism in hamsters

British Journal Of Nutrition ◽

10.1079/bjn2001509 ◽

2002 ◽

Vol 87 (3) ◽

pp. 227-237 ◽

Cited By ~ 26

Author(s):

Elke A. Trautwein ◽

Claudia Schulz ◽

Dörte Rieckhoff ◽

Angelika Kunath-Rau ◽

Helmut F. Erbersdobler ◽

...

Keyword(s):

Bile Acid ◽

Acid Metabolism ◽

Ldl Cholesterol ◽

Cholesterol Absorption ◽

Bile Acid Metabolism ◽

Acid Excretion ◽

Hepatic Cholesterol ◽

Intestinal Cholesterol Absorption ◽

Cholesterol Lowering ◽

Esterified Sterols

4-Desmethylsterols and -stanols reduce plasma total cholesterol (TC) and LDL cholesterol by inhibition of intestinal cholesterol absorption, while the cholesterol-lowering potential of 4,4′-dimethylsterols is less well defined. The present study aimed to compare the effects of 4-desmethylsterols, -stanols, and 4,4′-dimethylsterols on plasma and hepatic cholesterol, sterol excretion and bile acid metabolism. Male golden Syrian hamsters were fed diets containing 13 g/100 g fat, 0·08 g/100 g cholesterol and 0 (control), 0·24 or 0·48 % (w/w) esterified 4-desmethylsterols (sterols) and esterified hydrogenated 4-desmethylsterols (stanols) from common vegetable oils or esterified 4,4′-dimethylsterols from rice bran oil for 5 weeks. Sterol and stanol esters at the dose of 0·24 % were equally effective and significantly (P<0·05) lowered TC by 15 %, while 0·24 % 4,4-dimethylsterols reduced TC by 10 %. Liver total and esterified cholesterol concentrations were significantly (P<0·05) lowered by 40, 22, 43 and 31 % in hamsters fed 0·48 % sterols, 0·24 % stanols, 0·48 % stanols or 0·48 % dimethylsterols, respectively. Daily faecal bile acid excretion and hepatic cholesterol 7α-hydroxylase activity were not altered, indicating that sterols, stanols and dimethylsterols had no effect on the intestinal re-absorption of bile acids or on hepatic bile acid synthesis. Daily excretion of cholesterol was significantly higher in hamsters fed esterified sterols and stanols, but was only slightly increased in those fed dimethylsterols. The results indicate that esterified sterols and stanols were equally effective in lowering plasma TC and LDL cholesterol, while dimethylsterol esters caused a weaker cholesterol-lowering effect. Sterols and stanols achieve their cholesterol-lowering effect by stimulating faecal cholesterol excretion through inhibiting intestinal cholesterol absorption, but do not affect bile acid excretion. Other mechanisms need to be considered to explain the effect on plasma and hepatic cholesterol of dimethylsterols.

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