Hypocholesterolemic Potential Research Articles

Replacing Saturated Fat with PUFA-Rich (Sunflower Oil) or MUFA-Rich (Rapeseed, Olive and High-Oleic Sunflower Oil) Fats Resulted in Comparable Hypocholesterolemic Effects in Cholesterol-Fed Hamsters

Recent studies have suggested that monounsaturated fatty acid (MUFA)-rich dietary fats do not have the same plasma cholesterol-lowering effects whereby rapeseed oil was more effective than olive oil. This phenomenon could be explicable by the content of other fatty acids or plant sterols. To further evaluate the effects of different MUFA-rich oils (18:1-rich sunflower oil, rapeseed oil, olive oil) in comparison to polyunsaturated (PUFA)-rich oils (18:2-rich sunflower oil) and saturated fat (palm stearin) on cholesterol and bile acid metabolism, male Syrian golden hamsters were fed semipurified diets containing 5% fat and 0.2% cholesterol for 5 weeks. To test whether oil refining would have an impact on the cholesterol-lowering potential, unrefined and refined varieties of rapeseed and olive oil were included. After 5 weeks, plasma total cholesterol (TC) was highest with palm stearin (10.0 ± 2.6 mmol/l) while the MUFA- or PUFA-rich fats significantly lowered TC. The lowest TC concentrations were found with refined rapeseed, cold pressed rapeseed and 18:2-rich sunflower oil (6.7 ± 1.2; 7.1 ± 0.7 and 7.1 ± 0.7 mmol/l, respectively), whereas TC was 10–15% higher (not significant) with 18:1-rich sunflower, virgin and refined olive oil. Liver cholesterol concentrations were lowest in hamsters fed palm stearin or 18:2-rich sunflower oil while MUFA-rich fats increased hepatic cholesteryl ester accumulation, especially of cholesteryl oleate. There were no significant differences in the fecal neutral sterol and bile acid excretion. These data demonstrate that MUFA-rich dietary fats, e.g. rapeseed, olive and 18:1-rich sunflower oil, are comparable in their hypocholesterolemic potential and cause similar effects on plasma cholesterol as 18:2-rich sunflower oil in hamsters when the dietary cholesterol intake is moderate.

Hypocholesterolemic Potential of Oat Bran Treated with an Endo‐β‐D‐glucanase from Bacillus subfilis

ABSTRACTOat bran was treated with endo‐β‐D‐glucanases to hydrolyze β(1 ± 3) (1 ± 4)‐glucans. Hydrolysis of β‐glucans reduced the in vitro viscosity of a suspension of oat bran. Untreated oat bran and hydrolyzed oat bran were incorporated into hypercholesterolemic purified diets and fed to rats for 4 wk; a diet containing cellulose was used as a control. Hepatic cholesterol accumulation was affected by dietary treatment and was less in the oat bran group than in the enzyme‐treated oat bran or cellulose groups. Thus, functional properties of (1±3) (1±4)‐β‐D‐glucan, such as viscosity, appear to be related to its hypocholesterolemic potential.

The biochemical role and hypocholesterolaemic potential of the legume Cassia fistula in hypercholesterolaemic rats

The hypocholesterolaemic effect of Cassia fistula was investigated using hypercholesterolaemic male albino rats. Hypercholesterolaemia was induced by feeding on a mixture of cholesterol plus cholic acid for a 12 weeks period. Hypercholesterolaemia was characterized by significant increase in the average levels of total lipids, total cholesterol, and triglycerides and significant decrease in phospholipids content. Administration of Cassia fistula significantly reduced blood and liver total lipids. Brain, spleen, kidneys and heart followed nearly the same trend but with moderate effect. Blood, liver, kidneys, spleen and heart total cholesterol was significantly reduced, while that of brain was not affected. The level of triglycerides was markedly improved. There was a moderate rise, however, in phospholipids content in all studied organs. That is to say a marked progress in the correction of lipid metabolism occurred. Also, administration of Cassia fistula induced a significant decrease in the high activities of serum GOT, GPT, alkaline and acid phosphatase and the values nearly returned the initial values. Total serum protein, albumin (A), globulin (G), A/G, free amino acids, uric acid and creatinine were also determined and their values were improved and attained nearly the normal values of the control group.

Dose Response to a Dietary Oat Bran Fraction in Cholesterol-Fed Rats

The two objectives of this research were to improve the cholesterol-fed rat as a model for evaluating the hypocholesterolemic potential of foods and to determine the relationship between serum and liver lipid levels in the cholesterol-fed rat and the ingestion of nine levels of a high fiber oat flour (HFOF) derived from oat bran. Ingestion of 0.2% cholic acid, sodium cholate or sodium taurocholate with 1% cholesterol (CH) significantly elevated serum and liver CH, liver triglycerides and liver weight compared to those values in control rats fed diets not containing CH and bile acids; 0.05 and 0.1% cholic acid with 1% CH were also effective. Ingestion of increasing amounts of HFOF, containing 0-10% dietary fiber, by rats made hypercholesterolemic with 1% CH and 0.1% cholic acid in the diet produced a significant inverse relationship between serum and liver cholesterol levels and HFOF intake; r = 0.48, p less than 0.0001 for serum CH and r = 0.55, p less than 0.0001 for liver CH. Because of the similarities in the responses of humans and of the cholesterol-fed rat to oat fiber ingestion, this dose-response relationship in the rat model suggests that larger intakes of soluble oat fiber sources may be accompanied by greater reduction in serum CH levels in humans.