phytosterols and campesterol

Microalgae are photosynthetic microorganisms that produce numerous bioactive molecules that can be used as food supplement to prevent chronic disease installation. Indeed, they produce phycobiliproteins, polysaccharides, lipids, carotenoids and sterolic compounds. The use of microalgae in human nutrition provide a mixture of these molecules with synergistic effect. The aim of this review is to present the specific roles played by the xanthophylls, and specifically astaxanthin and fucoxanthin, two high added value carotenoids, and by microalgal phytosterols such as β-sitosterol, campesterol and stigmasterol on several cell mechanisms involved in the prevention of cardiometabolic diseases and cancers. This review explains how these microalgal molecules modulate cell signaling pathways involved in carbohydrate and lipid metabolisms, inflammation, apoptosis, invasion and metastasis. Xanthophylls and phytosterols are involved in the reduction of inflammatory markers in relation with the regulation of the c-Jun N-terminal kinases and nuclear factor-kappa B signaling pathways, and suppression of production of pro-inflammatory mediators. Xanthophylls act on glucose and lipid metabolisms via both the upregulation of peroxisome proliferator-activated receptors (PPARs) and glucose transporters and its effects on the expression of enzymes involved in fatty acid synthesis and cholesterol metabolism. Their anti-cancer effects are related to the induction of intrinsic apoptosis due to down-regulation of key regulatory kinases. The anti-angiogenesis, anti-proliferative and anti-invasive effects are correlated with decreased production of endothelial growth factors and of matrix metalloproteinases. Phytosterols have a major role on cholesterol absorption via modification of the activities of Niemann-Pick C1 like 1 and ATP-binding cassette transporters and on cholesterol esterification. Their action are also related with the modulation of PPARs and sterol regulatory element-binding protein-1 activities.

Topics: Apoptosis; Carbohydrate Metabolism; Cardiovascular Diseases; Cholesterol; Dietary Supplements; Humans; Lipid Metabolism; Metabolic Diseases; Microalgae; Neoplasms; Phytosterols; Signal Transduction; Sitosterols; Xanthophylls

Non-cholesterol sterols are validated biomarkers for intestinal cholesterol absorption and endogenous cholesterol synthesis. However, their use in metabolic disturbances has not been systematically explored. Therefore, we conducted a systematic review to provide an overview of non-cholesterol sterols as markers for cholesterol metabolism in different metabolic disorders. Potentially relevant studies were retrieved by a systematic search of three databases in July 2018 and ninety-four human studies were included. Cholesterol-standardized levels of campesterol, sitosterol and cholestanol were collected to reflect cholesterol absorption and those of lathosterol and desmosterol to reflect cholesterol synthesis. Their use as biomarkers was examined in the following metabolic disorders: overweight/obesity (

Topics: Biomarkers; Cardiovascular Diseases; Cholesterol; Desmosterol; Diabetes Mellitus; Humans; Intestinal Absorption; Intestinal Diseases; Kidney Diseases; Liver Diseases; Metabolic Diseases; Obesity; Overweight; Phytosterols; Sitosterols; Sterols

Human studies have shown diurnal rhythms of cholesterol and bile acid synthesis, but a better understanding of the role of the circadian system in cholesterol homeostasis is needed for the development of targeted interventions to improve metabolic health. Therefore, we performed a systematic literature search on the diurnal rhythms of cholesterol synthesis and absorption markers and of bile acid synthesis markers. We also examined the diurnal rhythms of the cholesterol synthesis markers lathosterol and desmosterol, and of the cholesterol absorption markers cholestanol, campesterol, and sitosterol in serum samples from the Bispebjerg study. These samples were collected every three hours over a 24-hour period in healthy males (

Topics: Adolescent; Adult; Bile Acids and Salts; Biomarkers; Cholestanol; Cholesterol; Circadian Rhythm; Desmosterol; Female; Humans; Intestinal Absorption; Male; Middle Aged; Phytosterols; Sitosterols; Time Factors; Young Adult

Dietary sterols are nutritionally interesting compounds which can suffer oxidation reactions. In the case of plant sterols, they are being widely used for food enrichment due to their hypocholesterolemic properties. Besides, cholesterol and plant sterols oxidation products are associated with the development of cardiovascular and neurodegenerative diseases, among others. Therefore, the evaluation of the particular factors affecting sterol degradation and oxysterols formation in foods is of major importance. The present work summarizes the main results obtained in experiments which aimed to study four aspects in this context: the effect of the heating treatment, the unsaturation degree of the surrounding lipids, the presence of antioxidants on sterols degradation, and at last, oxides formation. The use of model systems allowed the isolation of some of these effects resulting in more accurate data. Thus, these results could be applied in real conditions.

Topics: Animals; Antioxidants; Cholesterol; Hot Temperature; Humans; Kinetics; Models, Theoretical; Oxygen; Oxysterols; Phytosterols; Sitosterols; Stigmasterol

Phytosterols are a kind of plant metabolite belonging to the triterpene family. These compounds are essential biomolecules for human health, and so they must be taken from foods. β-Sitosterol, campesterol, and stigmasterol are the main phytosterols found in plants. Phytosterols have beneficial effects on human health since they are able to reduce plasma cholesterol levels and have antiinflammatory, antidiabetic, and anticancer activities. However, there are many difficulties in obtaining them, since the levels of these compounds produced from plant raw materials are low and their chemical synthesis is not economically profitable for commercial exploitation. A biotechnological alternative for their production is the use of plant cell and hairy root cultures. This review is focused on the biosynthesis of phytosterols and their function in both plants and humans as well as the different biotechnological strategies to increase phytosterol biosynthesis. Special attention is given to describing new methodologies based on the use of recombinant DNA technology to increase the levels of phytosterols.

Topics: Anti-Inflammatory Agents; Antineoplastic Agents; Biological Availability; Biotechnology; Cholesterol; Empirical Research; Humans; Hypoglycemic Agents; Phytosterols; Plant Cells; Plants; Sitosterols; Stigmasterol

Intake of plant sterol (PS)-enriched foods effectively lowers plasma total- and LDL-cholesterol concentrations while increasing plasma PS concentrations. The magnitude of this increase has not been systematically assessed. This study aimed to investigate the effect of PS-enriched foods on plasma PS concentrations by performing a meta-analysis of randomized controlled studies.. Published PS intervention studies reporting plasma PS concentrations were searched through June 2012. Studies were selected that fulfilled pre-defined in- and exclusion criteria. Data were extracted, particularly on campesterol, sitosterol, total- and LDL-cholesterol. Random-effects models were used to calculate net effects while weighing each study by the inverse of its variance. Potential sources of heterogeneity were investigated.. The meta-analysis included data from 41 studies (55 strata) with in total 2084 subjects. The average dose of PS from enriched foods was 1.6 g/d (range: 0.3-3.2 g/d). Plasma sitosterol and campesterol concentrations were increased by on average 2.24 μmol/L (31%) and 5.00 μmol/L (37%), respectively, compared to control. Total- and LDL-cholesterol were reduced by on average 0.36 mmol/L (5.9%) and 0.33 mmol/L (8.5%), respectively. The increase in sitosterol and campesterol was impacted by the dose of PS, the baseline PS concentration and the PS composition of the test products. In the highest PS dose category (2.0-3.2 g/d), increases in sitosterol and campesterol were on average 3.56 and 7.64 μmol/L, respectively.. Intake of PS-enriched foods increases plasma sitosterol and campesterol concentrations. However, total PS remain below 1% of total sterols circulating in the blood.

Topics: Cholesterol; Cholesterol, LDL; Diet; Food, Fortified; Humans; Phytosterols; Randomized Controlled Trials as Topic; Risk Factors; Sitosterols

The impact of increased serum concentrations of plant sterols on cardiovascular risk is unclear. We conducted a systematic review and meta-analysis aimed to investigate whether there is an association between serum concentrations of two common plant sterols (sitosterol, campesterol) and cardiovascular disease (CVD). We systematically searched the databases MEDLINE, EMBASE, and COCHRANE for studies published between January 1950 and April 2010 that reported either risk ratios (RR) of CVD in relation to serum sterol concentrations (either absolute or expressed as ratios relative to total cholesterol) or serum sterol concentrations in CVD cases and controls separately. We conducted two meta-analyses, one based on RR of CVD contrasting the upper vs. the lower third of the sterol distribution, and another based on standardized mean differences between CVD cases and controls. Summary estimates were derived by fixed and random effects meta-analysis techniques. We identified 17 studies using different designs (four case-control, five nested case-control, three cohort, five cross-sectional) involving 11 182 participants. Eight studies reported RR of CVD and 15 studies reported serum concentrations in CVD cases and controls. Funnel plots showed evidence for publication bias indicating small unpublished studies with non-significant findings. Neither of our meta-analyses suggested any relationship between serum concentrations of sitosterol and campesterol (both absolute concentrations and ratios to cholesterol) and risk of CVD. Our systematic review and meta-analysis did not reveal any evidence of an association between serum concentrations of plant sterols and risk of CVD.

Topics: Cardiovascular Diseases; Cholesterol; Diet; Epidemiologic Methods; Humans; Phytosterols; Publication Bias; Risk Factors; Sitosterols

Investigating cholesterol metabolism, which derives from balancing cholesterol synthesis and absorption, opens new perspectives in the pathogenesis of dyslipidemias and the metabolic syndrome (MS). Cholesterol metabolism is studied by measuring plasma levels of campesterol, sitosterol and cholestanol, that is, plant sterols which are recognised as surrogate cholesterol-absorption markers and lathosterol or squalene, that is, cholesterol precursors, which are considered surrogate cholesterol-synthesis markers. This article presents current knowledge on cholesterol synthesis and absorption, as evaluated by means of cholesterol precursors and plant sterols, and discusses patterns of cholesterol balance in the main forms of primary hyperlipidaemia and MS. Understanding the mechanism(s) underlying these patterns of cholesterol synthesis and absorption will help to predict the response to hypolipidemic treatment, which can then be tailored to ensure the maximum clinical benefit for patients.

Topics: Biomarkers; Cholestanol; Cholesterol; Dyslipidemias; Humans; Lipid Metabolism; Metabolic Syndrome; Phytosterols; Sitosterols

This study examined the effect of plant sterols added, together with an emulsifying agent, to a low-fat yoghurt on the serum lipid and plant sterol values in moderately hypercholesterolaemic volunteers. Study I was a randomized double-blind, cross-over trial. For 4 weeks, 15 volunteers consumed yoghurt containing 1 g plant sterols or a placebo yoghurt. Study II was a randomized, double-blind, parallel-group study. For 8 weeks, the sterol group (n = 12) ingested daily two yoghurts (2 g/day plant sterols) and the placebo group (n = 14) ingested two yoghurts without plant sterols. Study I: compared with the placebo, the sterol yoghurt reduced serum total cholesterol by 0.15 mmol/l (2.2%, P=0.235) and low-density lipoprotein (LDL) cholesterol by 0.19 mmol/l (4.3%, P=0.082), and increased serum campesterol by 0.26 mg/100 ml (P=0.006) and sitosterol by 0.11 mg/100 ml (P=0.015). Study II: compared with the placebo, the sterol yoghurt reduced serum total cholesterol by 0.41 mmol/l (6.3%, P=0.167) and LDL cholesterol by 0.28 mmol/l (6.4%, P=0.306), and increased serum campesterol by 0.28 mg/100 ml (P=0.016) and sitosterol by 0.40 mg/100 ml (P=0.206). Meta-analysis: the pooled treatment difference was -0.34 mmol/l (5.2%, P=0.173) in total cholesterol and was -0.26 mmol/l (-5.8%, P=0.261) in LDL cholesterol, when the sterol yoghurt was compared with the placebo. A low-fat yoghurt enriched with 1-2 g/day plant sterols reduced serum cholesterol levels in moderately hypercholesterolaemic subjects. Campesterol and sitosterol serum levels increased, but their concentration remained in the range of normal values.

Topics: Adult; Analysis of Variance; Anticholesteremic Agents; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Double-Blind Method; Female; Humans; Hypercholesterolemia; Lipids; Male; Middle Aged; Phytosterols; Sitosterols; Yogurt

Lowering lipid levels in the cardiovascular prevention we confine ourselves to measure the cholesterol level and care less for the background effects. Namely blood cholesterol level beyond the amount consumed with the diet highly depends on balance of intestinal absorption/secretion and synthesis. Studying the rate of absorption and synthesis has come only recently into the foreground of interest. Many observations proved that using even the strongest cholesterol lowering drug - beyond reducing the synthesis in the liver - may be associated with an up to 50 percent increase of the intestinal cholesterol absorption. When studying the effectiveness of statins in everyday practice we measure only the decrease of serum cholesterol level as the final result, and do not examine the changes in the synthesis and absorption. The amount of cholesterol synthesized or absorbed can be determined in an indirect way by measuring that of the non-cholesterol sterols (phytosterols). The absorption markers are campesterol, sitosterol, avenasterol as well as cholestanol. The biosynthesis of cholesterol correlates with the level of lathosterol, cholestanol, desmostenol. In practice the concentration of lathosterol or lathosterol/cholesterol can be considered the marker of synthesis and the campesterol or campesterol/cholesterol ratio the marker of absorption. So recent study results show that while inhibiting the cholesterol synthesis with statin the cholesterol absorption increases and the absorption inhibitor ezetimibe is associated with boost of synthesis. The increase in absorption caused by statins can be reduced or prevented by combining with ezetimibe. These data confirm that combination of statin and ezetimibe, inhibiting simultaneously both the synthesis and absorption provides the most effective cholesterol-level lowering with the least side-effects.

Topics: Anticholesteremic Agents; Azetidines; Biomarkers; Cholestanol; Cholesterol; Cholesterol, Dietary; Ezetimibe; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypercholesterolemia; Intestinal Absorption; Phytosterols; Sitosterols

Sterols found in all eukaryotic organisms are membrane components which regulate the fluidity and the permeability of phospholipid bilayers. Certain sterols in minute amounts, such as campesterol in Arabidopsis thaliana, are precursors of oxidized steroids acting as growth hormones collectively named brassinosteroids. The crucial importance of brassinosteroids upon growth and development has been established through the study of a set of dwarf mutants affected in brassinosteroid synthesis or perception. Some of these dwarfs are, in fact, deficient in the final steps of sterol biosynthesis and their developmental phenotypes are primarily caused by a depletion in the sterol precursor for brassinosteroids. Recently, the characterization of genes encoding sterol biosynthetic enzymes and the isolation of novel plant lines affected in the expression of those genes, either by insertional or classical mutagenesis, overexpression or cosuppression, have shed new light on the involvement of sterols in biological processes such as embryonic development, cell and plant growth, and fertility, which will be presented and discussed in this review article.

Topics: Arabidopsis; Cholesterol; Mutation; Phytosterols; Plant Development; Sitosterols

Topics: Arabidopsis; Brassinosteroids; Cell Membrane; Cell Wall; Cholestanols; Cholesterol; Mutation; Phytosterols; Signal Transduction; Sitosterols; Steroids, Heterocyclic

Brassinosteroids are polyhydroxylated derivatives of common plant membrane sterols such as campesterol. They occur throughout the plant kingdom and have been shown by genetic and biochemical analyses to be essential for normal plant growth and development. Numerous reviews have detailed the recent progress in our understanding of the biosynthesis, physiological responses, and molecular modes of action of brassinosteroids. It is clear that like their animal steroid counterparts, brassinosteroids have a defined receptor, can regulate the expression of specific genes, and can orchestrate complex physiological responses involved in growth. This review summarizes the current status of BR research, pointing out where appropriate the similarities and differences between the mechanism of action of brassinosteroids and the more thoroughly studied animal steroid hormones.

Topics: Animals; Brassinosteroids; Cell Differentiation; Cell Division; Cholestanols; Cholesterol; Mevalonic Acid; Phytosterols; Plants; Signal Transduction; Squalene; Steroids; Steroids, Heterocyclic; Triterpenes

Topics: Anticholesteremic Agents; Cholesterol; Cholesterol, LDL; Clinical Trials as Topic; Esters; Humans; Hypolipidemic Agents; Myocardial Ischemia; Phytosterols; Sitosterols

Biosynthesis of steroidal plant hormones, brassinosteroids, was studied using the cell culture system of Catharanthus roseus. Feeding labeled compounds of possible intermediates to the cultured cells, followed by analyzing the metabolites by gas chromatography-mass spectrometry disclosed the pathways from a plant sterol, campesterol, to brassinolide. There are two pathways, named the early C6-oxidation pathway and late C6-oxidation pathway, both of which would be operating in a wide variety of plants. Recent findings of brassinosteroid-deficient mutants of Arabidopsis and the garden pea by several groups, and the possible blocked steps of the mutants in the biosynthetic pathways are also introduced.

Topics: Brassinosteroids; Cells, Cultured; Cholestanols; Cholesterol; Molecular Structure; Phytosterols; Plant Growth Regulators; Plants, Medicinal; Steroids, Heterocyclic

Topics: Cholesterol; Humans; Intestinal Absorption; Phytosterols; Sitosterols

Increased physical activity is inversely related to the risk to develop cardiovascular disease (CVD). In a recent systematic review, it was reported that CVD patients had an increased cholesterol absorption and a decreased synthesis as compared with control participants. As increased physical activity levels reduce CVD risk, we hypothesized that exercise training will reduce cholesterol absorption and increase endogenous cholesterol synthesis in older overweight and obese men.. A randomized, controlled, crossover trial was performed. Seventeen apparently healthy older overweight and obese men were randomized to start with an aerobic exercise or no-exercise control period for 8 weeks, separated by 12 weeks washout. Fasting serum total cholesterol (TC) and non-cholesterol sterol concentrations were measured at baseline, and after 4 and 8 weeks.. The aerobic exercise program did not affect serum TC concentrations. In addition, exercise did not affect TC-standardized serum concentrations of sitosterol and cholestanol that are markers for cholesterol absorption. However, a trend for reduced TC-standardized campesterol concentrations, which is another validated marker for cholesterol absorption, was observed as compared with control. Lathosterol concentrations, reflecting cholesterol synthesis, did not differ between both periods.. Aerobic exercise training for 8 weeks did not lower serum TC concentrations in older overweight and obese men, but a trend towards a decrease in the cholesterol absorption marker campesterol was found. The cholesterol synthesis marker lathosterol did not change.. posted on www.clinicaltrials.gov as NCT03272061 on 7 September 2017.

Topics: Aged; Biomarkers; Body Mass Index; Cardiovascular Diseases; Cholesterol; Cross-Over Studies; Exercise; Exercise Therapy; Humans; Life Style; Male; Middle Aged; Obesity; Overweight; Phytosterols; Sterols; Surveys and Questionnaires

Sodium/glucose cotransporter 2 (SGLT2) inhibitors decrease plasma triglyceride levels and slightly increase low-density lipoprotein (LDL-c) and high-density lipoprotein cholesterol (HDL-c). However, the mechanisms underlying such changes in the blood lipid profile remain to be determined. We investigated how empagliflozin affects plasma markers of cholesterol absorption and synthesis, and evaluated the relationship between changes in these markers and blood lipids in patients with type 2 diabetes.. In a randomized, active-controlled, open-label trial, 51 patients were randomly allocated in 2:1 ratio to receive empagliflozin 10 mg/day (n = 32) or standard therapy (n = 19) for 12 weeks. We measured plasma levels of lathosterol as a marker of cholesterol synthesis, and campesterol and sitosterol as markers of cholesterol absorption, at baseline and 12 weeks after treatment. In the empagliflozin group, serum HDL-c, but not LDL-c, significantly increased between baseline and 12 weeks (54.4 ± 16.3 vs. 58.8 ± 19.6 mg/dl; p = 0.0006), whereas in the standard therapy group, HDL-c and LDL-c remained unchanged. In the empagliflozin group, plasma campesterol also increased significantly (4.14 ± 1.88 vs. 4.90 ± 2.26 μg/ml, p = 0.0008), whereas no change in plasma campesterol or sitosterol was found in the control group. Although plasma lathosterol showed no change in the whole empagliflozin group, it decreased significantly in patients who were not taking statins. In statin non-users, plasma lathosterol decreased significantly after treatment with empagliflozin (2.71 ± 0.99 vs. 1.91 ± 0.99 μg/ml, p < 0.05). In the empagliflozin group, changes in plasma campesterol correlated positively with changes in HDL-c.. Empagliflozin increases serum campesterol, a marker of cholesterol absorption, in patients with type 2 diabetes. This increase may be associated with SGLT2 inhibitor-induced increases in HDL cholesterol.

Topics: Benzhydryl Compounds; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Diabetes Mellitus, Type 2; Glucosides; Humans; Phytosterols

Anagliptin, a dipeptidyl peptidase-4 inhibitor, is reported to reduce the level of low-density lipoprotein cholesterol (LDL-C). The underlying mechanism of this effect and effect on lipid metabolism however remains uncertain.. We therefore evaluate the effects of anagliptin on lipid metabolism-related markers compared with those of sitagliptin. The study was a secondary analysis using data obtained from the Randomized Evaluation of Anagliptin versus Sitagliptin On low-density lipoproteiN cholesterol in diabetes (REASON) trial. This trial in patients with type 2 diabetes at a high risk of cardiovascular events and on statin therapy showed that anagliptin reduced LDL-C levels to a greater extent than sitagliptin. Cholesterol absorption (campesterol and sitosterol) and synthesis (lathosterol) markers were measured at baseline and 52 weeks in the study cohort (n = 353).. There was no significant difference in the changes of campesterol or sitosterol between the two treatment groups (p = 0.85 and 0.55, respectively). Lathosterol concentration was increased significantly at 52 weeks with sitagliptin treatment (baseline, 1.2 ± 0.7 μg/mL vs. 52 weeks, 1.4 ± 1.0 μg/mL, p = 0.02), whereas it did not change in the anagliptin group (baseline, 1.3 ± 0.8 μg/mL vs. 52 weeks, 1.3 ± 0.7 μg/mL, p = 0.99). The difference in absolute change between the two groups showed a borderline significance (p = 0.06).. These findings suggest that anagliptin reduces LDL-C level by suppressing excess cholesterol synthesis, even in combination with statin therapy. Trial registration ClinicalTrials.gov number NCT02330406. https://clinicaltrials.gov/ct2/show/NCT02330406; registered January 5, 2015.

Topics: Aged; Biomarkers; Cholesterol; Cholesterol, LDL; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Dyslipidemias; Female; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Japan; Male; Middle Aged; Phytosterols; Pyrimidines; Sitagliptin Phosphate; Sitosterols; Time Factors; Treatment Outcome

Topics: Adult; Arginine; Cholesterol; Cross-Over Studies; Dietary Supplements; Female; Gas Chromatography-Mass Spectrometry; Humans; Male; Middle Aged; Nitrates; Nitrites; Phytosterols; Young Adult

Information regarding dietary effects on plasma oxyphytosterol concentrations as well as on the origin of oxyphytosterols is scarce. We hypothesized that plant sterols are oxidized in the intestinal lumen, mediated by microbial activity, followed by uptake into the circulation. To address this hypothesis, we carried out, a randomized, double blind, crossover study in 13 healthy subjects, who consumed for 3 weeks control and plant stanol ester enriched margarines (3.0g/d plant stanols) separated by a 4-week wash-out period. Plasma oxy(phyto)sterols were determined via GC-MS/MS, while microbiota analyses were performed on fecal DNA using a phylogenetic microarray to assess microbial composition and diversity. Plasma plant sterol concentrations did not correlate with plasma oxyphytosterols concentrations at baseline. Plant stanol consumption reduced serum sitosterol and campesterol concentrations (-37% and -38%), respectively (p<0.001), as well as plasma concentrations of 7β-OH-campesterol (-24%; p<0.05), 7β-OH-sitosterol (-17%; p<0.05) and 7-keto-sitosterol (-13%; p<0.05). Although the intestinal microbiota composition and diversity of the faecal contents were not different between the two periods, we observed significant correlations between several specific bacterial groups and plasma plant sterol, but not with plasma oxyphytosterol concentrations. In conclusion, plant stanol ester consumption reduced serum plant sterol and plasma oxyphytosterol concentrations, while intestinal microbiota composition and diversity were not changed. To definitely answer the effects of microbiota on oxyphytosterol formation, future studies could examine oxyphytosterol concentrations after changing intestinal microbial composition or by measuring intestinal oxyphytosterol formation after providing labelled non-oxidized plant sterols.

Topics: Adolescent; Adult; Cholesterol; Cross-Over Studies; Diet; DNA; Feces; Female; Gastrointestinal Microbiome; Humans; Intestinal Mucosa; Male; Middle Aged; Oxygen; Phylogeny; Phytosterols; Sitosterols; Young Adult

This double-blind, randomized, placebo-controlled, cross-over intervention-study was conducted in healthy volunteers to evaluate the effects of plant sterol ester supplemented margarine on cholesterol, non-cholesterol sterols and oxidative stress in serum and monocytes. Sixteen volunteers, average age 34 years, with no or mild hypercholesterolemia were subjected to a 4 week period of daily intake of 3g plant sterols per day supplied via a supplemented margarine on top of regular eating habits. After a wash-out period of one week, volunteers switched groups. Compared to placebo, a diet supplementation with plant sterols increased serum levels of plant sterols such as campesterol (+0.16±0.19mg/dL, p=0.005) and sitosterol (+0.27±0.18mg/dL, p<0.001) and increased markers of cholesterol synthesis such as desmosterol (+0.05±0.07mg/dL, p=0.006) as well as lathosterol (+0.11±0.16mg/dL, p=0.012). Cholesterol serum levels, however, were not changed significantly (+18.68±32.6mg/dL, p=0.052). These findings could not be verified in isolated circulating monocytes. Moreover, there was no effect on monocyte activation and no differences with regard to redox state after plant sterol supplemented diet. Therefore, in a population of healthy volunteers with no or mild hypercholesterolemia, consumption of plant sterol ester supplemented margarine results in increased concentrations of plant sterols and cholesterol synthesis markers without affecting total cholesterol in the serum, activation of circulating monocytes or redox state.

Topics: Adult; Biomarkers; Cell Separation; Cholesterol; Cross-Over Studies; Diet; Double-Blind Method; Female; Flow Cytometry; Gas Chromatography-Mass Spectrometry; Humans; Male; Margarine; Monocytes; Oxidation-Reduction; Oxidative Stress; Oxygen; Phytosterols; Reactive Oxygen Species; Sitosterols; Young Adult

Plant sterols (PS) lower plasma LDL-cholesterol through partial inhibition of intestinal cholesterol absorption. Although PS themselves are poorly absorbed, increased intakes of PS result in elevated plasma concentrations. In this paper, we report time curves of changes in plasma PS during 12 weeks of PS intake. Furthermore, the impact of cholesterol synthesis and absorption on changes in plasma PS is explored.. The study was a double-blind, randomized, placebo-controlled, parallel-group study with the main aim to investigate the effects of PS on vascular function (clinicaltrials.gov: NCT01803178). Hypercholesterolemic but otherwise healthy men and women (n = 240) consumed low-fat spreads without or with added PS (3 g/d) for 12 weeks after a 4-week run-in period. Blood sampling was performed at week 0, 4, 8 and 12. Basal cholesterol-standardized concentrations of lathosterol and sitosterol + campesterol were used as markers of cholesterol synthesis and absorption, respectively. In the PS group, plasma sitosterol and campesterol concentrations increased within the first 4 weeks of intervention by 69% (95%CI: 58; 82) starting at 7.2 μmol/L and by 28% (95%CI: 19; 39) starting at 11.4 μmol/L, respectively, and remained stable during the following 8 weeks. Placebo-corrected increases in plasma PS were not significantly different between high and low cholesterol synthesizers (P-values >0.05). Between high and low cholesterol absorbers, no significant differences were observed, except for the cholesterol-standardized sum of four major plasma PS (sitosterol, campesterol, brassicasterol and stigmasterol) showing larger increases in low absorbers (78.3% (95%CI: 51.7; 109.5)) compared to high absorbers (40.8% (95%CI: 19.9; 65.5)).. Increases in plasma PS stabilize within 4 weeks of PS intake and do not seem impacted by basal cholesterol synthesis or absorption efficiency. This study was registered at clinicaltrials.gov (NCT01803178).

Topics: Adult; Aged; Cholestadienols; Cholesterol; Cholesterol, LDL; Double-Blind Method; Female; Humans; Hypercholesterolemia; Intestinal Absorption; Lipid Metabolism; Male; Middle Aged; Phytosterols; Prospective Studies; Sitosterols; Stigmasterol

Hyperglycemia is a major public health problem worldwide and there is increasing demand for prevention of postprandial hyperglycemia in diabetic, prediabetic, and healthy humans.. We investigated whether rice bran and triterpene alcohol and sterol preparation (TASP) lowered hyperglycemia in mice and humans. Brown rice and white rice supplemented with TASP lowered the postprandial hyperglycemia in humans. TASP and its components (cycloartenol [CA], 24-methylene cycloartanol, β-sitosterol, and campesterol) decreased postprandial hyperglycemia in C57BL/6J mice. Glucose transport into everted rat intestinal sacs and human HuTu80 cells transfected with sodium-glucose cotransporter-1 (SGLT1) was significantly reduced by the addition of CA. Intracellular localization analysis suggested that SGLT1 translocation to the apical plasma membrane was inhibited when the cells were treated with CA.. We demonstrated for the first time that TASP from rice bran lowered postprandial hyperglycemia in mice and humans. The smaller increase in blood glucose following TASP consumption may be due to the CA-induced decrease in glucose absorption from the intestine, which may be related to decreased membrane translocation of SGLT1.

Topics: Adult; Animals; Blood Glucose; Body Mass Index; Body Weight; Cell Line, Tumor; Cholesterol; Dietary Fiber; Humans; Hyperglycemia; Insulin; Male; Mice; Mice, Inbred C57BL; Oryza; Phytosterols; Rats; Rats, Wistar; Single-Blind Method; Sitosterols; Sodium-Glucose Transporter 1; Sterols; Triterpenes

Epidemiological studies have reported inconsistent results on the relationship between increased plant sterol concentrations with cardiovascular risk, which might be related to the formation of oxyphytosterols (plant sterol oxidation products) from plant sterols. However, determinants of oxyphytosterol formation and metabolism are largely unknown. It is known, however, that serum plant sterol concentrations increase after daily consumption of plant sterol enriched products, while concentrations decrease after plant stanol consumption. Still, we have earlier reported that fasting oxyphytosterol concentrations did not increase after consuming a plant sterol- or a plant stanol enriched margarine (3.0g/d of plant sterols or stanols) for 4weeks. Since humans are in a non-fasting state for most part of the day, we have now investigated effects on oxyphytosterol concentrations during the postprandial state. For this, subjects consumed a shake (50g of fat, 12g of protein, 67g of carbohydrates), containing no, or 3.0g of plant sterols or plant stanols. Blood samples were taken up to 8h and after 4h subjects received a second shake (without plant sterols or plant stanols). Serum oxyphytosterol concentrations were determined in BHT-enriched EDTA plasma via GC-MS/MS. 7β-OH-campesterol and 7β-OH-sitosterol concentrations were significantly higher after consumption of a mixed meal enriched with plant sterol esters compared to the control and plant stanol ester meal. These increases were seen only after consumption of the second shake, illustrative for a second meal effect. Non-oxidized campesterol and sitosterol concentrations also increased after plant sterol consumption, in parallel with 7β-OH concentrations and again only after the second meal. Apparently, plant sterols and oxyphytosterols follow the same second meal effect as described for dietary cholesterol. However, the question remains whether the increase in oxyphytosterols in the postprandial phase is due to absorption or endogenous formation.

Topics: Adult; Cholesterol; Fasting; Feeding Behavior; Female; Healthy Volunteers; Humans; Male; Meals; Oxidation-Reduction; Phytosterols; Postprandial Period; Sitosterols

Dietary phytosterols, plant sterols structurally similar to cholesterol, reduce intestinal cholesterol absorption and have many other potentially beneficial biological effects in humans. Due to limited information on phytosterol levels in foods, however, it is difficult to quantify habitual dietary phytosterol intake (DPI). Therefore, we sought to identify a plasma biomarker of DPI.. Data were analyzed from two feeding studies with a total of 38 subjects during 94 dietary periods. DPI was carefully controlled at low, intermediate, and high levels. Plasma levels of phytosterols and cholesterol metabolites were assessed at the end of each diet period. Based on simple ordinary least squares regression analysis, the best biomarker for DPI was the ratio of plasma campesterol to the endogenous cholesterol metabolite 5-α-cholestanol (R2 = 0.785, P < 0.0001). Plasma campesterol and 5-α-cholestanol levels varied greatly among subjects at the same DPI level, but were positively correlated at each DPI level in both studies (r > 0.600; P < 0.01).. The ratio of plasma campesterol to the coordinately regulated endogenous cholesterol metabolite 5-α-cholestanol is a biomarker of dietary phytosterol intake. Conversely, plasma phytosterol levels alone are not ideal biomarkers of DPI because they are confounded by large inter-individual variation in absorption and turnover of non-cholesterol sterols. Further work is needed to assess the relation between non-cholesterol sterol metabolism and associated cholesterol transport in the genesis of coronary heart disease.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Biomarkers; Cholestanol; Cholesterol; Diet; Female; Humans; Male; Middle Aged; Phytosterols; Young Adult

Plant sterols (PSs) lower LDL cholesterol, an established risk factor for coronary artery disease (CAD). No direct evidence is available supporting a reduced risk of CAD for foods with added PSs. Endothelial dysfunction is seen as an early indicator of atherosclerotic damage.. This study was primarily designed to investigate the effect of a low-fat spread with added PSs on brachial artery endothelial function as measured by flow-mediated dilation (FMD). Second, effects on arterial stiffness, blood pressure, serum lipids, and plasma PS concentrations were investigated. We hypothesized that PSs would not worsen FMD but would rather modestly improve FMD.. This study had a double-blind, randomized, placebo-controlled, parallel design. After a 4-wk run-in period, 240 hypercholesterolemic but otherwise healthy men and women consumed 20 g/d of low-fat spread without (control) or with added PSs (3 g/d) during 12 wk. Pre- and postintervention, vascular function measurements and blood sampling were performed.. In total, 232 participants completed the study period. For the primary endpoint FMD, 199 participants were included in the statistical analysis. PS intake did not affect FMD (+0.01 percentage points; 95% CI: -0.73, 0.75) compared with control. Measures of arterial stiffness (pulse wave velocity and augmentation index) and blood pressure were also not significantly changed compared with control. After PS intervention, LDL cholesterol significantly decreased on average by 0.26 mmol/L (95% CI: -0.40, -0.12) or 6.7% compared with control. Plasma sitosterol and campesterol concentrations significantly increased in the PS group up to on average 11.5 μmol/L and 13.9 μmol/L (expressed as geometric means), respectively.. The intake of a low-fat spread with added PSs neither improved nor worsened FMD or other vascular function markers in hypercholesterolemic men and women. As expected, serum LDL cholesterol decreased, whereas plasma PSs increased after PS intake. This study was registered at clinicaltrials.gov as NCT01803178.

Topics: Biomarkers; Brachial Artery; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Dietary Carbohydrates; Dietary Fats; Dietary Proteins; Double-Blind Method; Endpoint Determination; Energy Intake; Female; Humans; Hypercholesterolemia; Life Style; Male; Middle Aged; Phytosterols; Pulse Wave Analysis; Sitosterols; Triglycerides

Butter is rich in saturated fat [saturated fatty acids (SFAs)] and can increase plasma low density lipoprotein (LDL) cholesterol, which is a major risk factor for cardiovascular disease. However, compared with other dairy foods, butter is low in milk fat globule membrane (MFGM) content, which encloses the fat. We hypothesized that different dairy foods may have distinct effects on plasma lipids because of a varying content of MFGM.. We aimed to investigate whether the effects of milk fat on plasma lipids and cardiometabolic risk markers are modulated by the MFGM content.. The study was an 8-wk, single-blind, randomized, controlled isocaloric trial with 2 parallel groups including overweight men and women (n = 57 randomly assigned). For the intervention, subjects consumed 40 g milk fat/d as either whipping cream (MFGM diet) or butter oil (control diet). Intervention foods were matched for total fat, protein, carbohydrates, and calcium. Subjects were discouraged from consuming any other dairy products during the study. Plasma markers of cholesterol absorption and hepatic cholesterol metabolism were assessed together with global gene-expression analyses in peripheral blood mononuclear cells.. As expected, the control diet increased plasma lipids, whereas the MFGM diet did not [total cholesterol (±SD): +0.30 ± 0.49 compared with -0.04 ± 0.49 mmol/L, respectively (P = 0.024); LDL cholesterol: +0.36 ± 0.50 compared with +0.04 ± 0.36 mmol/L, respectively (P = 0.024); apolipoprotein B:apolipoprotein A-I ratio: +0.03 ± 0.09 compared with -0.05 ± 0.10 mmol/L, respectively (P = 0.007); and non-HDL cholesterol: +0.24 ± 0.49 compared with -0.14 ± 0.51 mmol/L, respectively (P = 0.013)]. HDL-cholesterol, triglyceride, sitosterol, lathosterol, campesterol, and proprotein convertase subtilisin/kexin type 9 plasma concentrations and fatty acid compositions did not differ between groups. Nineteen genes were differentially regulated between groups, and these genes were mostly correlated with lipid changes.. In contrast to milk fat without MFGM, milk fat enclosed by MFGM does not impair the lipoprotein profile. The mechanism is not clear although suppressed gene expression by MFGM correlated inversely with plasma lipids. The food matrix should be considered when evaluating cardiovascular aspects of different dairy foods. This trial was registered at clinicaltrials.gov as NCT01767077.

Topics: Adult; Aged; Apolipoprotein A-I; Apolipoproteins B; Body Mass Index; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Dairy Products; Energy Intake; Fatty Acids; Feeding Behavior; Female; Gene Expression; Glycolipids; Glycoproteins; Healthy Volunteers; Homeostasis; Humans; Leukocytes, Mononuclear; Lipid Droplets; Male; Middle Aged; Nutrition Assessment; Phytosterols; Proprotein Convertase 9; Proprotein Convertases; Serine Endopeptidases; Single-Blind Method; Sitosterols; Triglycerides; Young Adult

The mechanism responsible for the lipid-lowering effect of dipeptidyl peptidase-4 (DPP-4) inhibitors remains unknown in humans. We evaluated the effect of anagliptin on serum lipid profiles, including cholesterol synthesis and absorption markers, in Japanese patients with type 2 diabetes.. Thirty patients with type 2 diabetes (20 - 70 years old, low-density lipoprotein cholesterol (LDL-C) level over 120 mg/dl, and no history of treatment with antidiabetic or antihyperlipidemic drugs) were enrolled. One hundred milligrams of anagliptin were administered twice a day for a month.. After treatment of anagliptin, the LDL-C and total cholesterol (TC) levels did not decrease overall, but the TC level decreased significantly in 28 patients whose HbA1c levels decreased. Lathosterol decreased significantly, whereas no changes in campesterol, sitosterol or cholestanol were observed.. These results of our study show no significant change in LDL-C, a tendency of decrease in TC and non-high-density lipoprotein cholesterol (non-HDL-C) after treatment of anagliptin for 1 month. Anagliptin therapy decreased the cholesterol synthesis marker lathosterol without changing cholesterol absorption markers.

Topics: Adult; Aged; Biomarkers; Cholestanol; Cholesterol; Cholesterol, LDL; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Female; Humans; Hypoglycemic Agents; Hypolipidemic Agents; Lipids; Lipoproteins, HDL; Male; Middle Aged; Phytosterols; Pilot Projects; Pyrimidines; Sitosterols; Young Adult

Post-menopausal women are at higher risk of cardiovascular disease and bone demineralization. Phytosterols (PS) may be used for hypercholesterolemia in some groups and β-cryptoxanthin (β-Cx) displays a unique anabolic effect on bone. Our aim was to assess the changes in cardiovascular and bone turnover markers from the oral intake of β-Cx and PS in post-menopausal women.. A randomized, double-blind, crossover study with β-Cx (0.75 mg/day) and PS (1.5 g/day), single and combined, was performed in 38 postmenopausal women. Diet was supplemented with 1 × 250 mL milk-based fruit drink/day for 4 weeks with a wash-out period of 4-weeks in between. Serum β-Cx and PS were determined by UPLC and CG-FID respectively. Outcome variables included markers of bone turnover and cardiovascular risk. Biological effect was assessed by paired t test and generalized estimating equations analysis that included the previous treatment, the order of intervention and the interactions. The intake of beverages containing β-Cx and PS brought about a significant increase in serum levels of β-Cx, β-sitosterol and campesterol. Intervention caused changes in almost all the markers while the order, previous treatment and the interaction did not reach statistical significance. Only the intake of the beverage containing β-Cx plus PS brought about significant decreases in total cholesterol, c-HDL, c-LDL and bone turnover markers.. β-Cx improves the cholesterol-lowering effect of PS when supplied simultaneously and this combination may also be beneficial in reducing risk of osteoporosis.. ClinicalTrials.gov number NCT01074723.

Topics: Administration, Oral; Aged; Bone and Bones; Cardiovascular Diseases; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Cross-Over Studies; Cryptoxanthins; Dietary Supplements; Dose-Response Relationship, Drug; Double-Blind Method; Female; Healthy Volunteers; Humans; Hypercholesterolemia; Middle Aged; Phytosterols; Postmenopause; Risk Factors; Sitosterols; Treatment Outcome; Triglycerides

Dietary lutein intake is postulated to interfere with the development of age-related macular degeneration (AMD). Because egg yolk-derived lutein has a high bioavailability, long-term consumption of lutein-enriched eggs might be effective in preventing AMD development, but alternatively might increase cardiovascular disease risk. Here, we report the effect of 1-y daily consumption of a buttermilk drink containing 1.5 lutein-rich egg yolks on serum lipid and lipoprotein and plasma lutein concentrations. Additionally, subgroups that could potentially benefit the most from the intervention were identified. Men and women who had early signs of AMD in at least 1 eye, but were otherwise healthy, participated in a 1-y randomized, placebo-controlled parallel intervention trial. At the start of the study, 101 participants were included: 52 in the experimental (Egg) group and 49 in the control (Con) group. Final analyses were performed with 45 participants in the Egg group and 43 participants in the Con group. As expected, the increase in plasma lutein concentrations in the Egg group was 83% higher than that in the Con group (P < 0.001). Changes in serum total, HDL, and LDL cholesterol, as well as the ratio of total cholesterol to HDL cholesterol, were not different between the 2 groups. Interestingly, participants classified as cholesterol absorbers had higher serum HDL cholesterol concentrations than participants classified as cholesterol synthesizers or participants with average campesterol-to-lathosterol ratios (P < 0.05) at baseline. In addition, cholesterol absorbers had a 229% higher increase in plasma lutein concentrations than participants who were classified as having an average campesterol-to-lathosterol ratio upon consumption of the lutein-enriched egg yolk drink (P < 0.05). Moreover, the change in serum HDL cholesterol upon consumption was significantly different between these 3 groups (P < 0.05). We suggest that cholesterol absorbers particularly might benefit from the lutein-enriched buttermilk drink. This study was registered at clinicaltrials.gov as NCT00902408.

Topics: Aged; Beverages; Cardiovascular Diseases; Cholesterol; Cholesterol, Dietary; Cholesterol, HDL; Cholesterol, LDL; Cultured Milk Products; Diet; Dietary Supplements; Disease Progression; Egg Yolk; Female; Humans; Intestinal Absorption; Lutein; Macular Degeneration; Male; Middle Aged; Phytosterols; Time Factors

We investigated the effect of dalcetrapib treatment on phytosterol levels in patients with familial combined hyperlipidemia (FCH) or familial hypoalphalipoproteinemia (FHA) due to mutations in apolipoprotein A1 (ApoA1) or ATP-binding cassette transporter A1 (ABCA1). Patients (n = 40) with FCH or FHA received dalcetrapib 600 mg or placebo in this 4-week, double-blind, crossover study. Lipids, apolipoproteins, cholesteryl ester transfer protein (CETP) activity and mass, and phytosterols were assessed. Dalcetrapib increased high-density lipoprotein cholesterol (HDL-C) and ApoA1 levels to a similar extent in FHA (+22.8, +13.9%) and FCH (+18.4, +12.1%), both p < 0.001 vs. placebo. Changes in CETP activity and mass were comparable for FHA (-31.5, +120.9%) and FCH (-26.6, +111.9%), both p < 0.0001 vs. placebo. Campesterol and lathosterol were unchanged in FHA (+3.8, +3.0%), but only campesterol was markedly increased in FCH (+25.0%, p < 0.0001 vs. placebo). Campesterol increased with dalcetrapib treatment in FCH but not in FHA, despite comparable HDL-C and ApoA1 increases, suggesting that ApoA1 and/or ABCA1 is essential for HDL lipidation by enterocytes in humans.

Topics: Amides; Apolipoprotein A-I; ATP Binding Cassette Transporter 1; Cholesterol; Cholesterol Ester Transfer Proteins; Cholesterol, HDL; Cross-Over Studies; Double-Blind Method; Esters; Humans; Hypoalphalipoproteinemias; Mutation; Phytosterols; Sulfhydryl Compounds; Treatment Outcome

Consumption of a cholesterol lowering dietary portfolio including plant sterols (PS), viscous fibre, soy proteins and nuts for 6 months improves blood lipid profile. Plant sterols reduce blood cholesterol by inhibiting intestinal cholesterol absorption and concerns have been raised whether PS consumption reduces fat soluble vitamin absorption.. The objective was to determine effects of consumption of a cholesterol lowering dietary portfolio on circulating concentrations of PS and fat soluble vitamins.. Using a parallel design study, 351 hyperlipidemic participants from 4 centres across Canada were randomized to 1 of 3 groups. Participants followed dietary advice with control or portfolio diet. Participants on routine and intensive portfolio involved 2 and 7 clinic visits, respectively, over 6 months.. No changes in plasma concentrations of α and γ tocopherol, lutein, lycopene and retinol, but decreased β-carotene concentrations were observed with intensive (week 12: p = 0.045; week 24: p = 0.039) and routine (week 12: p = 0.031; week 24: p = 0.078) portfolio groups compared to control. However, cholesterol adjusted β-carotene and fat soluble compound concentrations were not different compared to control. Plasma PS concentrations were increased with intensive (campesterol:p = 0.012; β-sitosterol:p = 0.035) and routine (campesterol: p = 0.034; β-sitosterol: p = 0.080) portfolio groups compared to control. Plasma cholesterol-adjusted campesterol and β-sitosterol concentrations were negatively correlated (p < 0.001) with total and LDL-C levels.. Results demonstrate that consuming a portfolio diet reduces serum total and LDL-C levels while increasing PS values, without altering fat soluble compounds concentrations. The extent of increments of PS with the current study are not deleterious and also maintaining optimum levels of fat soluble vitamins are of paramount necessity to maintain overall metabolism and health. Results indicate portfolio diet as one of the best options for CVD risk reduction.. clinicaltrials.gov Identifier: NCT00438425.

Topics: Adult; beta Carotene; Canada; Carotenoids; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Diet; Dietary Fiber; Feeding Behavior; Female; Follow-Up Studies; Humans; Hyperlipidemias; Lutein; Lycopene; Male; Middle Aged; Nuts; Phytosterols; Single-Blind Method; Sitosterols; Tocopherols; Triglycerides; Vitamin A; Vitamins

High-risk subjects with elevated C-reactive protein (CRP) are at high risk for cardiovascular events and frequently require potent statins or combined lipid-lowering therapy to achieve lipid targets and decrease inflammation. Our study aimed at evaluating the effects of three lipid-modifying therapies on LDL-cholesterol, CRP levels and markers of cholesterol absorption and synthesis.. A prospective intervention study was performed in high cardiovascular risk individuals receiving atorvastatin 10mg daily for four weeks. Those with CRP≥2.0mg/L were randomized to another four-week treatment period with atorvastatin 40mg, ezetimibe 10mg or the combination of atorvastatin 40mg / ezetimibe 10mg. Lipids, markers of cholesterol absorption (campesterol and β-sitosterol), and synthesis (desmosterol), as well as CRP were quantified at baseline and end of study.. One hundred and twenty two individuals were included. Atorvastatin alone or combined with ezetimibe reduced both LDL-cholesterol and CRP (P<0.002 vs. baseline; Wilcoxon); ezetimibe did not modify CRP. Ezetimibe-based therapies reduced absorption markers and their ratios to cholesterol (P<0.0001 vs. baseline, for all; Wilcoxon), whereas atorvastatin alone increased campesterol/cholesterol and β-sitosterol/cholesterol ratios (P<0.05 vs. baseline; Wilcoxon). In addition, ezetimibe also increased desmosterol and desmosterol/cholesterol ratio (P<0.0001 vs. baseline; Wilcoxon).. These results contribute to understanding the link between cellular cholesterol homeostasis, inflammation and lipid-modifying therapies. Our findings highlight the broader benefit of combined therapy with a potent statin and ezetimibe decreasing inflammation, and preventing increase in cholesterol biosynthesis, an effect not observed with ezetimibe alone.

Topics: Aged; Anticholesteremic Agents; Atorvastatin; Azetidines; C-Reactive Protein; Cardiovascular Diseases; Cholesterol; Desmosterol; Ezetimibe; Female; Heptanoic Acids; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Inflammation; Male; Middle Aged; Phytosterols; Prospective Studies; Pyrroles; Risk Factors; Sitosterols; Statistics, Nonparametric

The objective was to investigate the metabolic fate of phytosteryl/-stanyl fatty acid and ferulic acid esters upon consumption by healthy humans.. A capillary gas chromatographic methodology was employed to follow a randomized, single-blind three group crossover clinical trial and to quantify simultaneously individual intact esters, liberated phytosterols/-stanols and their metabolites in feces. Skimmed milk drinking yogurts enriched with complex mixtures of phytosteryl/-stanyl fatty acid esters and ferulates, respectively, were employed as food carriers.. On average, 73 % of total plant stanyl fatty acid esters and 80 % of total plant steryl fatty acid esters were hydrolyzed. Among the individuals, the hydrolysis rates ranged from 40 to 96 %. In addition, there were subject-dependent discrepancies between the amounts of phytosterols/-stanols actually determined in the feces and the calculated hydrolysis rates. On average, 69 % of the amounts of sterols/stanols expected from the amounts of remaining intact esters were found.. The study revealed large interindividual variability regarding the recoveries of dietary phytosteryl/-stanyl esters upon gastrointestinal passage in healthy humans. Nevertheless, there was a significant impact of the acid moiety (oleate=linoleate=linolenate>eicosanoate>palmitate>ferulate) on the hydrolysis rates; the influence of the phytosterol/-stanol moiety was less pronounced.

Topics: Adult; Anticholesteremic Agents; Beverages; Cholesterol; Coumaric Acids; Cross-Over Studies; Diet; Diet, Fat-Restricted; Digestion; Esterification; Fatty Acids; Feces; Food, Formulated; Humans; Hydrolysis; Male; Phytosterols; Single-Blind Method; Sitosterols; Yogurt; Young Adult

Non-cholesterol sterols reflect cholesterol metabolism. Statins reduce cholesterol synthesis usually with a rise in cholesterol absorption. Common hyperlipemias have shown different patterns of cholesterol metabolism. We evaluated whether cholesterol absorption and synthesis may differ after statin therapy in primary hyperlipemias.. We determined lipid profile, apoprotein B and serum sterols (lathosterol, sitosterol, campesterol by gas chromatography/mass spectrometry) before and after statins in 80 untreated hyperlipemic patients, 40 with polygenic hypercholesterolemia (PH) and 40 with familial combined hyperlipemia (FCH).. At baseline in FCH lathosterol was significantly higher while campesterol and sitosterol were significantly lower than in PH. After statins, the reduction in LDL-C did not significantly differ between the two groups; in PH there was a significant decrease of lathosterol from 96.1 to 52.6 102 μmol/mmol cholesterol (p=0.0001) with no significant modifications in campesterol and sitosterol; on the opposite, in FCH lathosterol decreased from 117 to 43 102 μmol/mmol cholesterol (p=0.0001) and campesterol and sitosterol significantly increased from 38 to 48 102 μmol/mmol cholesterol (p=0.0001), and from 75 to 86 102 μmol/mmol cholesterol, (p=0.022), respectively. After statin therapy only in FCH Δ-LDL-C showed a significant inverse correlation with Δ-sitosterol and with Δ-campesterol.. Primary hyperlipemias show different patterns of response to statins: in PH LDL reduction appears completely "synthesis inhibition" dependent, while in FCH LDL decrease appears to be synthesis dependent, partially limited by absorption increase. Studying cholesterol metabolism before and after hypolipemic therapy might be useful in identifying the best tailored treatment.

Topics: Adult; Aged; Atorvastatin; Cholesterol; Cholesterol, LDL; Female; Gas Chromatography-Mass Spectrometry; Heptanoic Acids; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypercholesterolemia; Hyperlipidemia, Familial Combined; Hyperlipidemias; Lipids; Male; Middle Aged; Phytosterols; Pyrroles; Simvastatin; Sitosterols

To assess the mechanism of long-term LDL-C-lowering effect of ezetimibe-plus-statin.. Coronary artery disease patients whose LDL-C ≥ 70 mg/dL after treatment with atorvastatin 10 mg/day or rosuvastatin 2.5 mg/day were randomly assigned to receive ezetimibe 10 mg/day + statin (n = 78) or double-dose statin (n = 72) for 52 weeks.. Greater LDL-C reduction was observed and maintained until 52 weeks in ezetimibe-plus-statin, while LDL-C levels re-increased after 12 weeks in double-dose statin. Although lathosterol/TC increased, campesterol/TC decreased more in ezetimibe-plus-statin. In contrast, lathosterol/TC unchanged and campesterol/TC increased, increasing campesterol/lathosterol ratio for 52 weeks in double-dose statin. Plasma PCSK9 levels were higher in double-dose statin than in ezetimibe-plus-statin at 12 weeks, but similar at 52 weeks.. Although the difference in PCSK9 between 2 groups was transient, that in both campesterol and lathosterol persisted until 52 weeks. These results demonstrated simultaneous inhibition of cholesterol absorption and synthesis provides stable and greater decrease in LDL-C levels.

Topics: Aged; Anticholesteremic Agents; Atorvastatin; Azetidines; Biomarkers; Cholesterol; Cholesterol, LDL; Coronary Artery Disease; Drug Administration Schedule; Drug Therapy, Combination; Ezetimibe; Female; Fluorobenzenes; Heptanoic Acids; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Japan; Male; Middle Aged; Phytosterols; Proprotein Convertase 9; Proprotein Convertases; Prospective Studies; Pyrimidines; Pyrroles; Rosuvastatin Calcium; Serine Endopeptidases; Sulfonamides; Time Factors; Treatment Outcome

The percentage of hypercholesterolemic individuals not reaching their LDL-cholesterol (LDL-C) goal remains high and additional therapeutic strategies should be evaluated. The objective of this study was to evaluate the cholesterol-lowering efficacy and mechanism of action of bile salt hydrolase-active Lactobacillus reuteri NCIMB 30242 capsules in hypercholesterolemic adults.. A total of 127 subjects completed a randomized, double-blind, placebo-controlled, parallel-arm, multicenter study. Subjects were randomized to consume L. reuteri NCIMB 30242 capsules or placebo capsules over a 9-week intervention period. The primary outcome was LDL-C relative to placebo at the study end point.. L. reuteri NCIMB 30242 capsules reduced LDL-C by 11.64% (P<0.001), total cholesterol by 9.14%, (P<0.001), non-HDL-cholesterol (non-HDL-C) by 11.30% (P < 0.001) and apoB-100 by 8.41% (P = 0.002) relative to placebo. The ratios of LDL-C/HDL-cholesterol (HDL-C) and apoB-100/apoA-1 were reduced by 13.39% (P = 0.006) and 9.00% (P = 0.026), respectively, relative to placebo. Triglycerides and HDL-C were unchanged. High-sensitivity C-reactive protein and fibrinogen were reduced by 1.05 mg/l (P = 0.005) and 14.25% (P = 0.004) relative to placebo, respectively. Mean plasma deconjugated bile acids were increased by 1.00 nmol/l (P=0.025) relative to placebo, whereas plasma campesterol, sitosterol and stigmasterol were decreased by 41.5%, 34.2% and 40.7%, respectively.. The present results suggest that the deconjugation of intraluminal bile acids results in reduced absorption of non-cholesterol sterols and indicate that L. reuteri NCIMB 30242 capsules may be useful as an adjunctive therapy for treating hypercholesterolemia.

Topics: Adult; Apolipoprotein A-I; Apolipoprotein B-100; Bile Acids and Salts; C-Reactive Protein; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Double-Blind Method; Female; Fibrinogen; Humans; Hypercholesterolemia; Intestinal Absorption; Limosilactobacillus reuteri; Male; Middle Aged; Phytosterols; Sitosterols; Stigmasterol

It is not known whether dietary intake of plant stanols or sterols changes the composition of arterial sterols. Therefore, we compared serum and carotid artery cholesterol and non-cholesterol sterols after plant stanol (staest) or sterol (steest) ester feeding in endarterectomized patients.. Elderly statin-treated asymptomatic patients undergoing carotid endarterectomy were randomized double-blind to consume staest (n=11) or steest (n=11) spread (2 g of stanol or sterol/day) for four weeks preoperatively. Non-cholesterol sterols from serum and carotid artery tissue were analysed with gas-liquid chromatography. Staest spread lowered serum total (17.2%), VLDL, and LDL cholesterol and serum triglycerides, while steest spread lowered serum total (13.8%) and LDL cholesterol levels from baseline (p<0.05 for all). Serum cholestanol and avenasterol were decreased in both groups, but campesterol and sitosterol were decreased by staest and increased by steest from baseline (p<0.05 from baseline and between the groups). Serum sitostanol to cholesterol ratio was increased by staest, but in arterial tissue this ratio was similar in both groups. On staest, lathosterol, campesterol, and sitosterol, and on steest sitosterol and avenasterol correlated significantly between serum and arterial tissue. Cholesterol metabolism, eg. lathosterol/campesterol, suggested that plant sterols were reduced in serum and in arterial tissue during staest.. The novel observations were that plant stanol ester consumption, in contrast to plant sterols, tended to reduce carotid artery plant sterols in statin-treated patients. Furthermore, despite increased serum sitostanol contents during plant stanol ester consumption, their arterial levels were unchanged suggesting that sitostanol is not taken up into the arterial wall.

Topics: Aged; Carotid Stenosis; Cholesterol; Condiments; Double-Blind Method; Endarterectomy, Carotid; Esters; Female; Humans; Male; Phytosterols; Plaque, Atherosclerotic; Preoperative Care; Sitosterols; Sterols

Phytosterols (PS) lower LDLc, but their effect on metabolic syndrome (MetS) remains unknown. We evaluated whether low-fat milk enriched with PS improves cardiovascular risk factors in these patients.. A randomised parallel trial employing 24 moderate-hypercholesterolaemic MetS patients and consisting of two 3-month intervention phases. After a 3-month healthy diet, patients were divided into two intervention groups: diet (n = 10) and diet + PS (n = 14) (2 g/day). A control group of 24 moderate-hypercholesterolaemic patients without MetS (matched in age and BMI) underwent the same procedure.. Neither dietary intervention nor enrichment of PS induced any improvement in the serum lipoprotein profile of MetS patients. By contrast, in the non-MetS population, a healthy diet effectively reduced TC, LDLc, non-HDLc and Apo B-100, with further decreases in TC (6.9%), LDLc (10.5%), non-HDLc (10.3%), Apo B-100 (6.2%) and Apo B-100/ApoA-I ratio (11.6%) being observed when PS were administered. No differences in LDL diameter, hsCRP or homocysteine were detected in any of the groups after consuming PS. This supplementation produced a significant increase in PS levels only in the non-MetS population.. PS therapy appears to be of little value to MetS patients, likely due to its reduced intestinal cholesterol absorption. The efficacy of PS as hypocholesterolaemic agents is thus limited.

Topics: Adult; Anticholesteremic Agents; Cardiovascular Diseases; Cholesterol; Cholesterol, Dietary; Dietary Supplements; Female; Humans; Hypercholesterolemia; Hypolipidemic Agents; Intestinal Absorption; Lipoproteins; Male; Metabolic Syndrome; Middle Aged; Phytosterols; Risk Factors; Severity of Illness Index; Sitosterols; Spain

Mechanisms by which trans fatty acids (TFA) from industrial (iTFA) and ruminant (rTFA) sources alter cholesterol homeostasis are virtually unknown. We compared the impact of dietary iTFA and rTFA on surrogate markers of cholesterol absorption (β-sitosterol and campesterol) and synthesis (lathosterol) in healthy men.. In a randomized, controlled double-blind crossover study, 38 healthy men consumed three experimental isoenergetic diets for 4 wk each. The three diets were (i) high in iTFA (10.2 g/2500 kcal), (ii) high in rTFA (10.2 g/2500 kcal) and (iii) control diet low in TFA from any source (2.2 g/2500 kcal). The sum of plasma β-sitosterol and campesterol concentrations was significantly reduced after the iTFA diet compared with the control diet (-12%, p=0.050). The reduction in combined β-sitosterol and campesterol levels was larger in magnitude after the rTFA diet (-29% versus the control diet and -20% versus the iTFA diet, p<0.0001). The TFA-rich diets had no impact on plasma lathosterol concentrations.. Very high intakes of rTFA and iTFA decrease cholesterol absorption but have no impact on cholesterol synthesis. Consumption of rTFA reduces cholesterol absorption to a greater extent than iTFA, but this difference does not ultimately affect plasma cholesterol concentrations.

Topics: Adolescent; Adult; Aged; Animals; Biomarkers; Cholesterol; Double-Blind Method; Homeostasis; Humans; Male; Middle Aged; Phytosterols; Ruminants; Sitosterols; Trans Fatty Acids; Young Adult

The relationship between plant sterol (PS) absorption and circulatory concentrations with cholesterol absorption and biosynthesis during PS consumption has yet to be clearly elucidated in humans. It is therefore essential to examine campesterol, β-sitosterol, and cholesterol absorption and cholesterol fractional synthesis rate (FSR) following PS consumption in individuals with high versus low basal circulatory PS concentrations.. A randomized, crossover trial was conducted in 82 hypercholesterolemic men consuming spreads with or without 2 g/d of PS for two 4-week periods, each separated by a 4-week washout. Endpoint tracer enrichments after ingestion of (2)H-labeled campesterol or β-sitosterol and (13)C-labeled cholesterol were determined by isotope ratio mass spectrometry.. For both phases of dietary intervention, the endpoint cholesterol absorption index was positively correlated with campesterol (r = 0.5864, p < 0.0001) and β-sitosterol (r = 0.4676, p < 0.0001) absorption indices; inversely, endpoint cholesterol FSR correlated negatively with the absorption indices of campesterol (r = -0.5004, p < 0.0009), β-sitosterol (r = -0.4154, p < 0.05), and cholesterol (r = -0.4056, p < 0.0001). PS intervention reduced absorption indices of campesterol, β-sitosterol, and cholesterol by 36.5% ± 2.7%, 39.3% ± 2.9%, and 34.3% ± 1.9%, respectively, but increased cholesterol FSR by 33.0% ± 3.3% relative to control. Endpoint circulatory PS levels (cholesterol adjusted) were positively associated with endpoint absorption indices of campesterol (r = 0.5586, p < 0.0001, for placebo; r = 0.6530, p < 0.0001, for PS intake) and cholesterol (r = 0.3683, p < 0.001 for placebo; r = 0.3469, p < 0.002, for PS intake) and were negatively associated with cholesterol FSR (r = -0.3551, p < 0.002, for placebo; r = -0.3643, p < 0.001, for PS intake). The cholesterol-lowering effect of PS was most pronounced among individuals falling within the 50th-75th percentiles of basal PS concentrations.. These data suggest that basal PS concentrations indicate not only sterol absorption efficiency but also the extent of PS-induced cholesterol reduction and thus might be clinically useful to predict the extent of cholesterol response to PS intervention within a given individual.

Topics: Adult; Aged; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Cross-Over Studies; Endpoint Determination; Humans; Hypercholesterolemia; Male; Middle Aged; Phytosterols; Sitosterols; Triglycerides

It has been demonstrated that statins can increase intestinal sterol absorption. Augments in phytosterolemia seems related to cardiovascular disease.. We examined the role of soluble fiber intake in endogenous cholesterol synthesis and in sterol absorption among subjects under highly effective lipid-lowering therapy.. In an open label, randomized, parallel-design study with blinded endpoints, subjects with primary hypercholesterolemia (n = 116) were assigned to receive during 12 weeks, a daily dose of 25 g of fiber (corresponding to 6 g of soluble fibers) plus rosuvastatin 40 mg (n = 28), rosuvastatin 40 mg alone (n = 30), sinvastatin 40 mg plus ezetimibe 10 mg plus 25 g of fiber (n = 28), or sinvastatin 40 mg plus ezetimibe 10 mg (n = 30) alone.. The four assigned therapies produced similar changes in total cholesterol, LDL-cholesterol, and triglycerides (p < 0.001 vs. baseline) and did not change HDL-cholesterol. Fiber intake decreased plasma campesterol (p < 0.001 vs. baseline), particularly among those patients receiving ezetimibe (p < 0.05 vs. other groups), and β-sitosterol (p = 0.03 vs. baseline), with a trend for lower levels in the group receiving fiber plus ezetimibe (p = 0.07). Treatment with rosuvastatin alone or combined with soluble fiber was associated with decreased levels of desmosterol (p = 0.003 vs. other groups). Compared to non-fiber supplemented individuals, those treated with fibers had weight loss (p = 0.04), reduced body mass index (p = 0.002) and blood glucose (p = 0.047).. Among subjects treated with highly effective lipid-lowering therapy, the intake of 25 g of fibers added favorable effects, mainly by reducing phytosterolemia. Additional benefits include improvement in blood glucose and anthropometric parameters.

Topics: Azetidines; Blood Glucose; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Dietary Fiber; Ezetimibe; Female; Fluorobenzenes; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Male; Middle Aged; Phytosterols; Pyrimidines; Rosuvastatin Calcium; Sitosterols; Sulfonamides; Triglycerides

Subjects with high HDL-C show elevated plasma markers of cholesterol absorption and reduced markers of cholesterol synthesis. We evaluated the effect of dalcetrapib, a cholesteryl ester transfer protein modulator, on markers of cholesterol homeostasis in healthy subjects.. Dalcetrapib was administered daily with or without ezetimibe in a randomized, open-label, crossover study in 22 healthy subjects over three 7-day periods: dalcetrapib 900 mg, ezetimibe 10mg, dalcetrapib 900 mg plus ezetimibe 10mg. Plasma non-cholesterol sterols lathosterol and desmosterol (cholesterol synthesis markers) and campesterol, β-sitosterol and cholestanol (intestinal cholesterol absorption markers) were measured. A hamster model was used to compare the effect of dalcetrapib and torcetrapib with or without ezetimibe on these markers and determine the effect of dalcetrapib on cholesterol absorption.. Dalcetrapib increased campesterol, β-sitosterol, and cholestanol by 27% (p = 0.001), 32% (p < 0.001), and 12% (p = 0.03), respectively, in man (non-cholesterol sterol/cholesterol ratio). Dalcetrapib+ezetimibe reduced campesterol by 11% (p = 0.02); β-sitosterol and cholestanol were unaffected. Lathosterol and desmosterol were unchanged with dalcetrapib, but both increased with ezetimibe alone (56-148%, p < 0.001) and with dalcetrapib + ezetimibe (32-38%, p < 0.001). In hamsters, dalcetrapib and torcetrapib increased HDL-C by 49% (p = 0.04) and 72% (p = 0.003), respectively. Unlike torcetrapib, dalcetrapib altered cholesterol homeostasis towards increased markers of cholesterol absorption; cholesterol synthesis markers were unaffected by either treatment. Dalcetrapib did not change plasma (3)H-cholesterol level but increased (3)H-cholesterol in plasma HDL vs non-HDL, after oral dosing of labeled cholesterol.. Dalcetrapib specifically increased markers of cholesterol absorption, most likely reflecting nascent HDL lipidation by intestinal ABCA1, without affecting markers of synthesis.

Topics: Amides; Animals; Anticholesteremic Agents; Azetidines; Biomarkers; Cholestanol; Cholesterol; Cholesterol Ester Transfer Proteins; Cholesterol, HDL; Cricetinae; Cross-Over Studies; Desmosterol; Esters; Ezetimibe; Homeostasis; Humans; Intestinal Absorption; Lipid Metabolism; Male; Mesocricetus; Models, Animal; Phytosterols; Quinolines; Sitosterols; Sulfhydryl Compounds; Switzerland

Cholesterol homeostasis, defined as the balance between absorption and synthesis, influences circulating cholesterol concentrations and subsequent coronary heart disease (CHD) risk. Statin therapy targets the rate-limiting enzyme in cholesterol biosynthesis and is efficacious in lowering CHD events and mortality. Nonetheless, CHD events still occur in some treated patients. To address differences in outcome during pravastatin therapy (40 mg/day), plasma markers of cholesterol synthesis (desmosterol, lathosterol) and fractional cholesterol absorption (campesterol, sitosterol) were measured, baseline and on treatment, in the Prospective Study of Pravastatin in the Elderly at Risk trial participants with (cases, n = 223) and without (controls, n = 257) a CHD event. Pravastatin therapy decreased plasma LDL-cholesterol and triglycerides and increased HDL-cholesterol concentrations to a similar extent in cases and controls. Decreased concentrations of the cholesterol synthesis markers desmosterol (-12% and -11%) and lathosterol (-50% and -56%) and increased concentrations of the cholesterol absorption markers campesterol (48% and 51%) and sitosterol (25% and 26%) were observed on treatment, but the magnitude of change was similar between cases and controls. These data suggest that decreases in cholesterol synthesis in response to pravastatin treatment were accompanied by modest compensatory increases in fractional cholesterol absorption. The magnitude of these alterations were similar between cases and controls and do not explain differences in outcomes with pravastatin treatment.

Topics: Aged; Aged, 80 and over; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Coronary Disease; Desmosterol; Female; Homeostasis; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Male; Phytosterols; Pravastatin; Sitosterols; Triglycerides

Subjects with increased cholesterol absorption might benefit more from statin therapy combined with a cholesterol absorption inhibitor. We assessed whether baseline cholesterol absorption markers were associated with response to ezetimibe/simvastatin therapy, in terms of LDL-cholesterol (LDL-C) lowering and cholesterol absorption inhibition, in patients with familial hypercholesterolemia (FH). In a posthoc analysis of the two-year ENHANCE trial, we assessed baseline cholesterol-adjusted campesterol (campesterol/TC) and sitosterol/TC ratios in 591 FH patients. Associations with LDL-C changes and changes in cholesterol absorption markers were evaluated by multiple regression analysis. No association was observed between baseline markers of cholesterol absorption and the extent of LDL-C response to ezetimibe/simvastatin therapy (beta = 0.020, P = 0.587 for campesterol/TC and beta<0.001, P = 0.992 for sitosterol/TC). Ezetimibe/simvastatin treatment reduced campesterol levels by 68% and sitosterol levels by 62%; reductions were most pronounced in subjects with the highest cholesterol absorption markers at baseline, the so-called high absorbers (P < 0.001). Baseline cholesterol absorption status does not determine LDL-C lowering response to ezetimibe/simvastatin therapy in FH, despite more pronounced cholesterol absorption inhibition in high absorbers. Hence, these data do not support the use of baseline absorption markers as a tool to determine optimal cholesterol lowering strategy in FH patients. However, due to the exploratory nature of any posthoc analysis, these results warrant further prospective evaluation in different populations.

Topics: Adult; Aged; Anticholesteremic Agents; Azetidines; Biomarkers; Cholesterol; Cholesterol, LDL; Double-Blind Method; Drug Therapy, Combination; Ezetimibe; Female; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hyperlipoproteinemia Type II; Intestinal Absorption; Male; Middle Aged; Phytosterols; Simvastatin; Sitosterols; Statistics as Topic

To date, there are very few clinical reports that have compared the effects of ezetimibe on lipid parameters between hypercholesterolemic patients with and without type 2 diabetes mellitus (T2DM). In this study, we recruited patients for hypercholesterolemic groups with T2DM (n = 42; men/women = 24/18; HbA1c = 6.7 ± 5.4%) and without T2DM (n = 21; men/women = 7/14; HbA1c = 5.3 ± 0.4%). Patients were prescribed ezetimibe at a dose of 10 mg/daily for the course of the 12-week study. At baseline and after 12 weeks of treatment, several lipid parameters, including serum low-density-lipoprotein cholesterol (LDL-C), non-high-density-lipoprotein cholesterol (non-HDL-C), high-sensitivity C-reactive protein (hs-CRP), and cholesterol synthesis/absorption-related markers, were measured. Compared with those at the baseline, the levels of LDL-C, non-HDL-C, campesterol, and sitosterol were significantly reduced after 12 weeks of ezetimibe treatment in both groups. After adjusting for confounding factors, such as age, gender, smoking, and BMI, the levels of LDL-C and non-HDL-C displayed significantly greater reductions in the patients with T2DM (-25.1 ± 13.6% in LDL-C, -20.5 ± 11.2% in non-HDL-C) than those without T2DM (-20.5 ± 7.8% in LDL-C, P < 0.05; -17.4 ± 7.6% in non-HDL-C, P < 0.05). The reduction of the level of cholestanol was significantly and positively correlated with those of LDL-C and non-HDL-C in the patients with T2DM. Taken together, these findings indicate that ezetimibe could reduce the levels of atherogenic lipoproteins to a greater extent in hypercholesterolemic patients with T2DM than in those without T2DM.

Topics: Aged; Azetidines; Biomarkers; Body Mass Index; C-Reactive Protein; Cardiovascular Diseases; Cholestanol; Cholesterol; Cholesterol, LDL; Diabetes Mellitus, Type 2; Ezetimibe; Female; Humans; Hypercholesterolemia; Hypolipidemic Agents; Lipids; Male; Middle Aged; Phytosterols; Sitosterols

To determine the effects of statin treatment and omega-3 polyunsaturated fatty acid supplementation on plasma plant sterol concentrations and cholesterol synthesis in patients with type 2 diabetes.. Plant sterol concentrations and lanosterol (a marker of cholesterol synthesis) were measured using a high sensitivity assay to assess the effect of double-blind daily treatment for 4 months with atorvastatin 20mg or placebo and, in a 2 × 2 factorial design, omega-3 ethyl esters 90 2g or placebo.. 658 patients were included in a per protocol analysis. The 4 treatment groups had similar mean [SD] age (63.5 years [11.7]), HbA(1c) (6.9% [1.1]) and diabetes duration (median 4 years [inter-quartile range 2, 8]). Atorvastatin treatment alone reduced low density lipoprotein (LDL) cholesterol by 1.4 mmol/l (44%, p<0.001), triglycerides by 0.3 mmol/l (20%, p<0.0001) and lanosterol by 0.36 μmol/l (72%, p<0.001). There was no significant placebo adjusted change in median [95% confidence intervals] total plant sterol concentrations (-0.77 μmol/l [inter-quartile range -2.13, 0.59]), although they were increased significantly with omega-3-acid EE90 treatment (3.23 μmol/l [1.28, 5.17]). There was a 27% smaller reduction in LDL cholesterol with atorvastatin treatment in low cholesterol synthesisers with high absorption, defined by changes at or above the median lanosterol and campesterol levels, respectively, compared with the obverse group (difference 0.42 mmol/l [0.21, 0.62]).. Treatment with atorvastatin in type 2 diabetes did not change median total plasma plant sterol concentrations, but LDL cholesterol was reduced most efficaciously in high cholesterol synthesisers with low intestinal cholesterol absorption.. Current controlled trials number ISRCTN: 76737502 (http://isrctn.org).

Topics: Anticholesteremic Agents; Atorvastatin; Cholesterol; Cholesterol, LDL; Diabetes Mellitus, Type 2; Docosahexaenoic Acids; Double-Blind Method; Drug Combinations; Eicosapentaenoic Acid; Heptanoic Acids; Humans; Lanosterol; Phytosterols; Pyrroles; Triglycerides

Clinical safety of consuming plant stanol ester spreads during pregnancy and lactation, the impact on maternal and infant serum and breast-milk cholesterol and the ratios (micromol/mmol of cholesterol) of synthesis and absorption markers were evaluated. Pregnant women (n 21) were randomised to control and dietary intervention groups, the intervention including advice to follow a balanced diet and to consume spreads enriched with plant stanol esters. Participants were followed during and after pregnancy and their infants up to 1 year of age. A mean 1.1 (sd 0.4) g consumption of plant stanols during pregnancy and 1.4 (sd 0.9) g 1 month post-partum increased sitostanol and the markers for cholesterol synthesis, lathosterol, lathosterol/campesterol and lathosterol/sitosterol, and reduced a marker for cholesterol absorption, campesterol, in maternal serum. In breast milk, desmosterol was lower in the intervention group, while no differences were detected between the groups in infants' serum. Plant stanol ester spread consumption had no impact on the length of gestation, infants' growth or serum beta-carotene concentration at 1 and 6 months of age, but the cholesterol-adjusted serum beta-carotene concentration was lowered at 1 month in the intervention group. Plant stanol ester spread consumption appeared safe in the clinical setting, except for potential lowering of infants' serum beta-carotene concentration, and was reflected in the markers of cholesterol synthesis and absorption in mothers' serum, encouraging further studies in larger settings.

Topics: Analysis of Variance; beta Carotene; Biomarkers; Child Development; Cholesterol; Desmosterol; Female; Humans; Infant; Infant, Newborn; Lactation; Margarine; Milk, Human; Phytosterols; Pregnancy; Safety; Sitosterols; Squalene

We measured plasma markers of cholesterol synthesis (lathosterol) and absorption (campesterol, sitosterol, and cholestanol) in order to compare the effects of maximal doses of rosuvastatin with atorvastatin and investigate the basis for the significant individual variation in lipid lowering response to statin therapy. Measurements were performed in participants (n = 135) at baseline and after 6 weeks on either rosuvastatin (40 mg/day) or atorvastatin (80 mg/day) therapy. Plasma sterols were measured using gas-liquid chromatography. Rosuvastatin and atorvastatin significantly (P < 0.001) altered plasma total cholesterol (C) levels by -40%, and the ratios of lathosterol/C by -64% and -68%, and campesterol/C by +52% and +72%, respectively, with significant differences (P < 0.001) between the treatment groups for the latter parameter. When using absolute values of these markers, subjects with the greatest reductions in both synthesis (lathosterol) and absorption (campesterol) had significantly greater reductions in total C than subjects in whom the converse was true (-46% versus -34%, P = 0.001), with similar effects for LDL-C. Rosuvastatin and atorvastatin decreased markers of cholesterol synthesis and increased markers of fractional cholesterol absorption, with rosuvastatin having significantly less effect on the latter parameter than atorvastatin. In addition, alterations in absolute values of plasma sterols correlated with the cholesterol lowering response.

Topics: Absorption; Adult; Aged; Atorvastatin; Biomarkers; Cholesterol; Diabetes Complications; Female; Fluorobenzenes; Glycated Serum Albumin; Glycation End Products, Advanced; Heptanoic Acids; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hyperlipidemias; Lipids; Lipoproteins; Male; Middle Aged; Phytosterols; Pyrimidines; Pyrroles; Rosuvastatin Calcium; Serum Albumin; Sterols; Sulfonamides

Phytosterols in natural foods are thought to inhibit cholesterol absorption. The Mediterranean diet is rich in phytosterol-containing plant foods.. To assess whether increasing phytosterol intake from natural foods was associated with a cholesterol-lowering effect in a substudy of a randomized trial of nutritional intervention with Mediterranean diets for primary cardiovascular prevention (PREDIMED study).. One hundred and six high cardiovascular risk subjects assigned to two Mediterranean diets supplemented with virgin olive oil (VOO) or nuts, which are phytosterol-rich foods, or advice on a low-fat diet. Outcomes were 1-year changes in nutrient intake and serum levels of lipids and non-cholesterol sterols.. Average phytosterol intake increased by 76, 158 and 15 mg/day in participants assigned VOO, nuts and low-fat diets, respectively. Compared to participants in the low-fat diet group, changes in outcome variables were observed only in those in the Mediterranean diet with nuts group, with increases in intake of fibre, polyunsaturated fatty acids and phytosterols (P < 0.020, all) and significant (P < 0.05) reductions of LDL-cholesterol (0.27 mmol/l or 8.3%) and the LDL/HDL-cholesterol ratio (0.29 mmol/l or 11.5%). Variations in saturated fat, cholesterol or fibre intake were unrelated to LDL-cholesterol changes. In the whole group, changes in serum sitosterol-to-cholesterol, which reflect those of dietary phytosterol intake and absorption, correlated inversely to LDL-cholesterol changes (r = -0.256; P = 0.008). In multivariate analyses, baseline LDL-cholesterol, increases in serum sitosterol ratios and statin use were independently associated with LDL-cholesterol reductions.. Small amounts of phytosterols in natural foods appear to be bioactive in cholesterol lowering.

Topics: Aged; Anticholesteremic Agents; Cardiovascular Diseases; Cholesterol; Diet, Fat-Restricted; Diet, Mediterranean; Dietary Fats; Energy Intake; Female; Food; Food Analysis; Humans; Isomerism; Lipids; Male; Middle Aged; Nuts; Olea; Patient Education as Topic; Phytosterols; Plants, Edible; Risk Factors; Sitosterols; Statistics as Topic; Surveys and Questionnaires

Plant sterol (PS) consumption lowers serum cholesterol levels, while modestly increasing plasma PS concentrations. Plasma PS concentrations may reflect sterol absorption, thus individuals with high plasma plant sterol (HPS) concentrations may show greater changes in circulating cholesterol and PS than individuals with low plasma plant sterol (LPS) concentrations. The objective of this study was to examine whether HPS and LPS concentrations are related to subsequent changes in plasma PS, serum lipid and C-reactive protein (CRP) concentrations, following dietary PS intake in otherwise healthy hypercholesterolemic men.. This single-blinded, randomized, diet-controlled study consisted of two 4-week phases, separated by a 4-week washout, where a diet with a placebo or the 2.0 g per day PS-enriched spread was consumed during the phases.. At baseline, men with HPS possessed higher (P<0.01) mean serum cholesterol concentration, while those with LPS had higher (P<0.05) body mass index. Following PS intake, plasma sum of campesterol plus sitosterol concentrations were elevated from 34.6+/-4.2 to 46.2+/-3.3 micromol l(-1) (mean+/-SE) and 16.5+/-0.9 to 20.8+/-1.2 micromol l(-1) after PS intake in men with HPS and LPS, respectively. Changes in plasma PS concentrations, however, were not different between individuals with either HPS or LPS baseline concentrations. Total cholesterol and low-density lipoprotein cholesterol levels were decreased (P<0.0001) by 6.3 and 7.8%, respectively, with PS consumption for all individuals. Changes in lipid parameters were not different between individuals with HPS or LPS baseline concentrations. No changes in CRP were apparent subsequent to PS intervention.. Baseline plasma PS concentrations are not associated or predictive of changes in serum cholesterol or plasma PS concentrations after PS intervention. Thus, individuals with HPS show similar increases in PS concentrations as individuals with LPS following PS supplementation. Plasma PS remained in the range of previously reported concentrations.

Topics: Body Mass Index; C-Reactive Protein; Cholesterol; Cholesterol, LDL; Food, Fortified; Humans; Lipids; Male; Middle Aged; Phytosterols; Single-Blind Method; Sitosterols

Consumption of plant sterol- or stanol-enriched margarines by statin users results in an additional LDL-cholesterol reduction of approximately 10 %, which may be larger than the average decrease of 3-7 % achieved by doubling the statin dose. However, whether this effect persists in the long term is not known. Therefore, we examined in patients already on stable statin treatment the effects of 85 weeks of plant sterol and stanol ester consumption on the serum lipoprotein profile, cholesterol metabolism, and bile acid synthesis. For this, a double-blind randomised trial was designed in which fifty-four patients consumed a control margarine with no added plant sterols or stanols for 5 weeks (run-in period). For the next 85 weeks, seventeen subjects continued with the control margarine and the other two groups with either a plant sterol (n 18) or plant stanol (n 19) (2.5 g/d each) ester-enriched margarine. Blood was sampled at the end of the run-in period and every 20 weeks during the intervention period. Compared with the control group, plant sterol and stanol ester consumption reduced LDL-cholesterol by 0.28 mmol/l (or 8.7 %; P = 0.08) and 0.42 mmol/l (13.1 %; P = 0.006) respectively after 85 weeks. No effects were found on plasma concentrations of oxysterols or 7 alpha-hydroxy-4-cholesten-3-one, a bile acid synthesis marker. We conclude that long-term consumption of both plant sterol and stanol esters effectively lowered LDL-cholesterol concentrations in statin users.

Topics: Analysis of Variance; Anticholesteremic Agents; Biomarkers; Cholestenones; Cholesterol; Cholesterol, LDL; Double-Blind Method; Esters; Female; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypercholesterolemia; Lipid Metabolism; Lipoproteins; Male; Margarine; Middle Aged; Phytosterols; Sitosterols; Stigmasterol

This study examined the effect of plant sterols added, together with an emulsifying agent, to a low-fat yoghurt on the serum lipid and plant sterol values in moderately hypercholesterolaemic volunteers. Study I was a randomized double-blind, cross-over trial. For 4 weeks, 15 volunteers consumed yoghurt containing 1 g plant sterols or a placebo yoghurt. Study II was a randomized, double-blind, parallel-group study. For 8 weeks, the sterol group (n = 12) ingested daily two yoghurts (2 g/day plant sterols) and the placebo group (n = 14) ingested two yoghurts without plant sterols. Study I: compared with the placebo, the sterol yoghurt reduced serum total cholesterol by 0.15 mmol/l (2.2%, P=0.235) and low-density lipoprotein (LDL) cholesterol by 0.19 mmol/l (4.3%, P=0.082), and increased serum campesterol by 0.26 mg/100 ml (P=0.006) and sitosterol by 0.11 mg/100 ml (P=0.015). Study II: compared with the placebo, the sterol yoghurt reduced serum total cholesterol by 0.41 mmol/l (6.3%, P=0.167) and LDL cholesterol by 0.28 mmol/l (6.4%, P=0.306), and increased serum campesterol by 0.28 mg/100 ml (P=0.016) and sitosterol by 0.40 mg/100 ml (P=0.206). Meta-analysis: the pooled treatment difference was -0.34 mmol/l (5.2%, P=0.173) in total cholesterol and was -0.26 mmol/l (-5.8%, P=0.261) in LDL cholesterol, when the sterol yoghurt was compared with the placebo. A low-fat yoghurt enriched with 1-2 g/day plant sterols reduced serum cholesterol levels in moderately hypercholesterolaemic subjects. Campesterol and sitosterol serum levels increased, but their concentration remained in the range of normal values.

Topics: Adult; Analysis of Variance; Anticholesteremic Agents; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Double-Blind Method; Female; Humans; Hypercholesterolemia; Lipids; Male; Middle Aged; Phytosterols; Sitosterols; Yogurt

Levels of cholesterol are regulated by its synthesis, absorption, and elimination. Plasma levels of phytosterols (e.g., sitosterol, campesterol) and ratios of these sterols to total cholesterol (TC) are reported to correlate with efficiency of intestinal cholesterol absorption, whereas levels of certain cholesterol precursor sterols (e.g., desmosterol, lathosterol) and their ratios to TC correlate with cholesterol biosynthesis. However, there is a paucity of published data concerning the effects of combined treatment using HMG-CoA reductase inhibitors (statins) and a cholesterol absorption inhibitor (ezetimibe) on these parameters.. To characterize the effects of ezetimibe co-administered with statins, compared with each treatment alone, on cholesterol precursor sterols and plasma phytosterol levels.. A post-hoc analysis was performed to determine the effects of treatment with ezetimibe 10 mg, simvastatin (10-80 mg), and atorvastatin (10-80 mg), alone or in combination, on these non-cholesterol sterols using plasma samples from two randomized controlled trials involving patients with primary hypercholesterolemia (low-density lipo protein [LDL-C] = 145-250 mg/dL; triglycerides < or = 350 mg/dL; N = 975) but without a recent (< or = 6-month) history of coronary heart disease (CHD) or either uncontrolled or newly diagnosed diabetes mellitus.. Ezetimibe monotherapy significantly reduced plasma sitosterol and campesterol concentrations from baseline compared with placebo (both p < 0.001), whereas statins significantly lowered desmo sterol and lathosterol levels (p < 0.001 vs. placebo). Co-administration of ezetimibe and statins significantly decreased plasma levels of all of these sterols (p < 0.001).. The observed effects of co-administration of ezetimibe and statins on non-cholesterol sterols are consistent with net inhibition of sterol absorption (driven by ezetimibe) in conjunction with net inhibition of cholesterol synthesis (driven by statins). The potential influence of treatment-induced changes in phytosterols on cardiovascular risk warrants further investigation in long-term, prospective, randomized controlled trials. This post-hoc study was by nature exploratory, and, because data from such analyses are not customarily adjusted for multiple comparisons, some associations may have emerged as statistically significant by chance. Future prospective randomized controlled studies may help to confirm our findings and address other research issues, such as the generalizability of our findings to patients with CHD or diabetes mellitus and possible dose:response relationships between escalating statin (or ezetimibe-statin) doses and circulating non-cholesterol levels.

Topics: Aged; Anticholesteremic Agents; Azetidines; Cholesterol; Double-Blind Method; Drug Therapy, Combination; Ezetimibe; Female; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypercholesterolemia; Male; Middle Aged; Phytosterols; Placebos; Simvastatin; Sitosterols; Sterols

Plant sterol (PS)-enriched foods have been shown to reduce plasma LDL-cholesterol concentrations. In most studies, however, PSs were incorporated into food products of high fat content.. We examined the effect of daily consumption of PS-supplemented low-fat fermented milk (FM) on the plasma lipid profile and on systemic oxidative stress in hypercholesterolemic subjects.. Hypercholesterolemic subjects (LDL-cholesterol concentrations >or=130 and

Topics: Animals; C-Reactive Protein; Carotenoids; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Double-Blind Method; Female; Fermentation; Humans; Hypercholesterolemia; Lipids; Male; Middle Aged; Milk; Oxidative Stress; Patient Compliance; Phytosterols; Sitosterols; Treatment Outcome; Triglycerides

To assess the effects of plant sterol or stanol ester consumption on their incorporation into erythrocytes and their effects on osmotic fragility of red blood cells.. Double-blind, randomized, placebo-controlled intervention trial.. Forty-one subjects on stable statin treatment - who already have increased serum plant sterol and stanol concentrations - first received for 4 weeks a control margarine. For the next 16 weeks, subjects were randomly assigned to one of three possible interventions. Eleven subjects continued with control margarine, 15 subjects with plant sterol ester enriched and 15 subjects with plant stanol ester-enriched margarine. Daily plant sterol or stanol intake was 2.5 g. Erythrocyte haemolysis was measured spectrophotometrically at five different saline concentrations.. Despite significant (P = 0.004) increases of, respectively, 42 and 59% in cholesterol-standardized serum sitosterol and campesterol concentrations in the plant sterol group as compared to the control group, campesterol levels in the red blood cells did not change (P = 0.196). Osmotic fragility did not change significantly (P = 0.757) in the plant sterol and plant stanol groups as compared to the control group.. We conclude that plant sterol and stanol ester consumption for 16 weeks does not change osmotic fragility of erythrocytes in statin-treated patients.. Netherlands Organisation for Health Research and Development (Program Nutrition: Health, Safety and Sustainability, Grant 014-12-010).

Topics: Anticholesteremic Agents; Cholesterol; Double-Blind Method; Erythrocytes; Esters; Female; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypercholesterolemia; Male; Margarine; Middle Aged; Osmolar Concentration; Phytosterols; Sitosterols

To assess causes for insufficient cholesterol-lowering response to pravastatin and plant stanol esters in children with heterozygous familial hypercholesterolemia (HeFH).. Nine of 16 children with HeFH who had not reached normocholesterolemia (< or =194 mg/dL [< or =5 mmol/L]) by 1 year after treatment (40 mg pravastatin and plant stanol ester) were called nonresponders. The 7 remaining children were responders. Serum noncholesterol sterol ratios (10(2) x mmol/mol of cholesterol), surrogate estimates of cholesterol absorption (cholestanol, campesterol, sitosterol) and synthesis (desmosterol and lathosterol), were studied at study baseline (on plant stanol esters) and during combination therapy with pravastatin and plant stanol esters.. Pravastatin decreased the serum levels of cholesterol and cholesterol synthesis markers, and increased the ratios of cholesterol absorption markers. Compared with the responders, the nonresponders had higher study baseline (on plant stanol esters) serum cholesterol concentrations (299 +/- 39 vs 251 +/- 35 mg/dL [7.7 +/- 1.0 vs 6.5 +/- 0.9 mmol/L]; P <.001) and higher respective ratios of campesterol (371 +/- 99 vs 277 +/- 67 10(2) x mmol/mol of cholesterol; P = .049) and sitosterol (176 +/- 37 vs 126 +/- 24 10(2) x mmol/mol of cholesterol; P = .008). The higher the ratio of cholestanol at study baseline, the smaller the 1-year percent reduction in cholesterol (r = .556; P = .025).. Pravastatin treatment increases the markers of cholesterol absorption and decreases those of cholesterol synthesis in HeFH during simultaneous inhibition of cholesterol absorption. Combined inhibition of cholesterol absorption and synthesis may not normalize serum lipids in those patients with the highest cholesterol levels, especially if signs of enhanced cholesterol absorption are detectable.

Topics: Adolescent; Anticholesteremic Agents; Child; Cholestanol; Cholesterol; Desmosterol; Female; Heterozygote; Humans; Hyperlipoproteinemia Type II; Male; Phytosterols; Pravastatin; Sitosterols; Triglycerides

The disposition and sterol-lowering effect of ezetimibe are associated with long-lasting enterosystemic circulation, which is initiated by secretion of ezetimibe and its glucuronide via intestinal P-glycoprotein (P-gp) (ABCB1) and the multidrug resistance-associated protein 2 (MRP2) (ABCC2) into gut lumen. Hepatic uptake and secretion may contribute to recycling. To obtain deeper insight into the intestinal and hepatic processes, the disposition of ezetimibe was studied in the presence of rifampin (INN, rifampicin), a modulator of P-gp, MRP2, and hepatic organic anion (uptake) transporting polypeptides (OATPs) (SLCOs).. The disposition of ezetimibe (20 mg orally) alone and after coadministration of rifampin (600 mg orally) was measured in a crossover study of 8 healthy subjects with the SLCO1B1 *1a/*1a genotype. Concentrations of ezetimibe and its glucuronide in serum, urine, and feces, as well as cholesterol, lathosterol, and the plant sterols campesterol and sitosterol in serum, were quantified by use of liquid chromatography and gas chromatography with mass spectrometric detection.. After rifampin administration, the maximum serum concentrations of ezetimibe and its glucuronide were significantly elevated (12.0+/-4.20 ng/mL versus 4.67+/-2.72 ng/mL, P=.017, and 282+/-73.8 ng/mL versus 107+/-35.3 ng/mL, P=.012, respectively). The area under the curve of ezetimibe was not affected (102+/-37.6 ng.h/mL versus 140+/-86.3 ng.h/mL, P=not significant), whereas that of the glucuronide was markedly increased (2150+/-687 ng.h/mL versus 1030+/-373 ng.h/mL, P=.012). Renal clearance remained unchanged. Fecal excretion of ezetimibe was markedly decreased (7.6+/-2.2 mg versus 10.4+/-1.8 mg, P=.036), whereas renal excretion of the glucuronide was strongly elevated (4.8+/-1.9 mg versus 2.0+/-1.2 mg, P=.049) after coadministration. The onset of a significant sterol-lowering effect of ezetimibe was significantly shortened by rifampin coadministration.. Coadministration of rifampin increases the maximum serum concentrations of ezetimibe but reduces its enterosystemic recycling, most likely by inhibition of the secretion of ezetimibe and its glucuronide via P-gp and MRP2.

Topics: Administration, Oral; Adult; Anticholesteremic Agents; ATP Binding Cassette Transporter, Subfamily B; ATP-Binding Cassette Sub-Family B Member 4; Azetidines; Cholesterol; Chromatography, Gas; Chromatography, Liquid; Cross-Over Studies; Enzyme Inhibitors; Ezetimibe; Feces; Female; Genotype; Glucuronides; Humans; Intestinal Absorption; Intestinal Mucosa; Intestines; Liver-Specific Organic Anion Transporter 1; Male; Multidrug Resistance-Associated Protein 2; Organic Anion Transporters; Phytosterols; Rifampin; Sitosterols; Time Factors

Myopathy, probably caused by 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibition in skeletal muscle, rarely occurs in patients taking statins. This study was designed to assess the effect of high-dose statin treatment on cholesterol and ubiquinone metabolism and mitochondrial function in human skeletal muscle.. Forty-eight patients with hypercholesterolemia (33 men and 15 women) were randomly assigned to receive 80 mg/d of simvastatin (n = 16), 40 mg/d of atorvastatin (n = 16), or placebo (n = 16) for 8 weeks. Plasma samples and muscle biopsy specimens were obtained at baseline and at the end of the follow-up.. The ratio of plasma lathosterol to cholesterol, a marker of endogenous cholesterol synthesis, decreased significantly by 66% in both statin groups. Muscle campesterol concentrations increased from 21.1 +/- 7.1 nmol/g to 41.2 +/- 27.0 nmol/g in the simvastatin group and from 22.6 +/- 8.6 nmol/g to 40.0 +/- 18.7 nmol/g in the atorvastatin group (P = .005, repeated-measurements ANOVA). The muscle ubiquinone concentration was reduced significantly from 39.7 +/- 13.6 nmol/g to 26.4 +/- 7.9 nmol/g (P = .031, repeated-measurements ANOVA) in the simvastatin group, but no reduction was observed in the atorvastatin or placebo group. Respiratory chain enzyme activities were assessed in 6 patients taking simvastatin with markedly reduced muscle ubiquinone and in matched subjects selected from the atorvastatin (n = 6) and placebo (n = 6) groups. Respiratory chain enzyme and citrate synthase activities were reduced in the patients taking simvastatin.. High-dose statin treatment leads to changes in the skeletal muscle sterol metabolism. Furthermore, aggressive statin treatment may affect mitochondrial volume.

Topics: Adult; Age Factors; Aged; Atorvastatin; Biopsy; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Citrate (si)-Synthase; Dose-Response Relationship, Drug; Double-Blind Method; Electron Transport; Female; Heptanoic Acids; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypercholesterolemia; Male; Middle Aged; Muscles; Patient Selection; Phytosterols; Pyrroles; Sex Factors; Simvastatin; Sitosterols; Succinate Cytochrome c Oxidoreductase; Time Factors; Ubiquinone

Plant sterol/stanol margarines are recommended as a lipid-lowering dietary supplement in the treatment of hypercholesterolemia. Parameters predicting the individual cholesterol-lowering effect have not been elucidated so far. Therefore, we investigated the responsiveness to sitostanol-supplemented margarine in a specially selected population.. From a total number of 137 male subjects with hypercholesterolemia, eight subjects with the lowest and eight subjects with the highest ratios of lathosterol to campesterol in serum were included in the study. They received 1 g sitostanol-supplemented margarine b.i.d. for four weeks. Serum lipoproteins, the cholesterol precursor lathosterol, the plant sterols campesterol and sitosterol were measured. Subjects with a low ratio of lathosterol to campesterol had a significant decrease of serum total cholesterol (-14.2%; p < 0.01) and LDL cholesterol (-13.8%; p < 0.01; responder). In subjects with a high ratio there was no significant change in total cholesterol and LDL cholesterol (2.2 and 4.3%; non-responder).. The ratio of serum lathosterol to campesterol predicts the reduction of total cholesterol and LDL cholesterol during administration of sitostanol-supplemented margarine in patients with mild hypercholesterolemia.

Topics: Adult; Anticholesteremic Agents; Cholesterol; Cholesterol, Dietary; Cholesterol, HDL; Cholesterol, LDL; Humans; Hypercholesterolemia; Male; Margarine; Middle Aged; Patient Selection; Phytosterols; Predictive Value of Tests; Sitosterols; Triglycerides

Hypercholesterolemia is a major risk factor for coronary artery disease. Therapeutic lifestyle changes include dietary modifications such as inclusion of phytosterols, which effectively lowers low-density lipoprotein (LDL) cholesterol in margarines and other fats. Their effectiveness in nonfat moieties is not yet established. The aim of this study was to examine if phytosterols alter the plasma lipoprotein profile when incorporated into nonfat orange juice.. After a 2-week run-in phase with orange juice, 72 mildly hypercholesterolemic healthy subjects were randomized to receive either placebo orange juice (placebo OJ) or plant sterol-fortified orange juice (sterol OJ) (2g/d) for 8 weeks. Fasting blood was obtained at baseline, after 2 weeks of OJ, and after 8 weeks of placebo/sterol-OJ supplementation. Sterol OJ supplementation significantly decreased total (7.2%), LDL (12.4%), and non-high-density lipoprotein (HDL) cholesterol (7.8%) compared with baseline and compared with placebo OJ (P<0.01). Apolipoprotein B levels were significantly decreased (9.5%) with sterol OJ. There were no significant changes in HDL cholesterol or triglycerides with the sterol OJ. While folate and B12 levels significantly increased, homocysteine levels were unchanged.. Orange juice fortified with plant sterols are effective in reducing LDL cholesterol and could easily be incorporated into the therapeutic lifestyle changes dietary regimen.

Topics: Adult; Aged; Apolipoproteins B; Beverages; Cholesterol; Cholesterol, LDL; Citrus; Double-Blind Method; Female; Folic Acid; Food, Fortified; Homocysteine; Humans; Hypercholesterolemia; Male; Middle Aged; Phytosterols; Sitosterols; Stigmasterol; Treatment Outcome; Vitamin B 12

Sitosterolemia is a recessively inherited disorder that results from mutations in either ABCG5 or G8 proteins, with hyperabsorption of dietary sterols and decreased hepatic excretion of plant sterols and cholesterol. As a consequence of markedly elevated plasma and tissue sitosterol and campesterol levels, premature atherosclerosis develops.. In this multicenter, double-blind, randomized, placebo-controlled study, we examined whether treatment with ezetimibe, an inhibitor of cholesterol absorption, reduces plant sterol levels in patients with sitosterolemia. After a 3-week placebo run-in, 37 patients were randomized to receive placebo (n=7) or ezetimibe 10 mg/d (n=30) for 8 weeks. Sitosterol concentrations decreased by 21% (P<0.001) in patients treated with ezetimibe compared with a nonsignificant 4% rise in those on placebo (between-group P<0.001). The reduction in sitosterol from baseline was progressive, with further decline observed at each subsequent biweekly visit. Campesterol also progressively declined, with a mean decrease after 8 weeks of 24% with ezetimibe and a mean increase of 3% with placebo treatment (between-group P<0.001). Reductions in plant sterol concentrations were similar irrespective of whether patients were undergoing concomitant treatment with resin or statin. Reductions in total sterols and apolipoprotein B were also observed. Ezetimibe was well tolerated, with no serious treatment-related adverse events or discontinuations due to adverse events being reported.. Ezetimibe produced significant and progressive reductions in plasma plant sterol concentrations in patients with sitosterolemia, consistent with the hypothesis that ezetimibe inhibits the intestinal absorption of plant sterols as well as cholesterol, leading to reductions in plasma concentrations.

Topics: Adolescent; Adult; Aged; Anticholesteremic Agents; Apolipoproteins B; Arteriosclerosis; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; ATP-Binding Cassette Transporters; Azetidines; Child; Cholesterol; Cholesterol, Dietary; Double-Blind Method; Ezetimibe; Female; Genes, Recessive; Humans; Intestinal Absorption; Lipid Metabolism, Inborn Errors; Lipoproteins; Male; Middle Aged; Phytosterols; Sitosterols; Treatment Outcome

To study the compliance and changes in plasma lipids, plant sterols, fat-soluble vitamins and carotenoids in children and parents with familial hypercholesterolemia (FH) consuming a plant sterol ester-enriched (PSE) spread.. A 26-week open-label follow-up of children who had previously been studied in a controlled cross-over design. The parents were also included in the open-label arm of the study.. Outpatient clinic for treatment of hyperlipidemia.. A total of 37 children (7-13 y) and 20 parents (32-51 y) diagnosed with 'definite' or 'possible' heterozygous FH. In all, 19 of the parents, but no children, used statins. All were patients at the Lipid Clinic, National Hospital in Oslo.. Subjects were recommended to eat 20 g/day of PSE spread as part of their lipid-lowering diet.. The mean intake of PSE spread was 13.7 and 16.5 g/days in the children and parents, respectively, corresponding to 1.2 and 1.5 g of plant sterols. Plasma total cholesterol decreased by 9.1% in both children (P<0.001) and parents (P=0.002). The corresponding decreases in LDL cholesterol were 11.4% (P<0.001) and 11.0% (P=0.012). Increases in serum lathosterol, campesterol and sitosterol, adjusted for total cholesterol, were observed in the children (31, 96, 48%, respectively, P<0.001) at the end of the controlled cross-over period. In the parents, serum campesterol and sitosterol, adjusted for total cholesterol, increased by 92 and 39%, respectively (P< 0.001). Lipid-adjusted serum alpha- and beta-carotene decreased by 17.4% (P=0.008) and 10.9% (P=0.018), respectively, in the children at the end of the controlled PSE period, but increased again during the follow-up. In the parents, serum alpha- and beta-carotene concentrations were unchanged, while serum lutein and lycopene decreased by 7.3% (P=0.037) and 14.6% (P=0.044), respectively.. Sustained efficacy of cholesterol reduction and long-term compliance of PSE intake were demonstrated in this study.

Topics: Adolescent; Adult; Carotenoids; Child; Cholesterol; Cross-Over Studies; Female; Humans; Hyperlipoproteinemia Type II; Lipids; Male; Margarine; Middle Aged; Patient Compliance; Phytosterols; Sitosterols; Treatment Outcome

We studied changes in serum cholestanol and plant sterols (indexes of cholesterol absorption) and cholesterol precursors (indexes of cholesterol synthesis) in response to cholesterol reduction by way of 1 year's treatment with atorvastatin (n = 102) and simvastatin (n = 105) treatments in patients with coronary heart disease. Serum cholesterol levels and ratios of the precursor sterols to cholesterol after 1 year of treatment were reduced in proportion to the pretreatment values (33% +/- 1% by simvastatin and 36% +/- 1% by atorvastatin; P <.01 for difference between groups) for cholesterol; the respective reductions in the precursor sterol:cholesterol ratios were also higher with atorvastatin (50% +/- 2% for lathosterol) than with simvastatin (42% +/- 1%; P <.01 between groups), but the ratio of squalene to cholesterol was increased (17% +/- 5%, P <.001) by atorvastatin. Plant sterol concentrations were gradually increased by atorvastatin but decreased initially by simvastatin. However, their ratios with respect to cholesterol were increased by as much as 82% with atorvastatin and by as much as 39% with simvastatin. In conclusion, effective inhibition of cholesterol synthesis and subsequent reduction in serum cholesterol levels by statins lead to increases in serum plant-sterol levels, probably as a result of reduced biliary secretion and enhanced absorption of these sterols. Because serum plant sterols have been claimed to be involved in the early development of atherosclerosis, the question arises whether continuously increasing serum plant sterols during long-term statin treatment should be prevented by cholesterol malabsorption (eg, by plant stanol ester consumption), especially in subjects with high baseline plant sterol values and effective sterol absorption.

Topics: Anticholesteremic Agents; Atorvastatin; Cholestanol; Cholesterol; Coronary Disease; Female; Heptanoic Acids; Humans; Male; Middle Aged; Phytosterols; Pyrroles; Simvastatin; Sitosterols; Squalene; Sterols

The dysmetabolic syndrome of insulin resistance and visceral obesity is characterized by elevated plasma concentration of triacylglycerol-rich lipoprotein (TRL) remnants that may be related to increased cardiovascular risk. Perturbed hepato-intestinal cholesterol metabolism may play a contributory role in this abnormality. We therefore investigated the association between plasma markers of cholesterol absorption and synthesis with TRL remnant metabolism in 35 men with the metabolic syndrome (MS). Plasma campesterol:cholesterol and lathosterol:cholesterol ratios were measured as estimates of cholesterol absorption and synthesis respectively. Remnant metabolism was assessed by measuring remnant-like particle-cholesterol (RLP-C), apolipoprotein (apo)B-48 and the fractional catabolic rate (FCR) of a labelled remnant-like emulsion. Compared with controls, subjects with the MS had significantly lower plasma campesterol:cholesterol ratio, but higher lathosterol:cholesterol ratio ( P <0.05). Plasma RLP-C and apoB-48 concentrations were also higher ( P <0.01) and the remnant-like emulsion FCR was lower ( P <0.05). The plasma campesterol:cholesterol ratio was inversely correlated ( P <0.05) with plasma triacylglycerols ( r =-0.346), RLP-C ( r =-0.443), apoB-48 ( r =-0.427) and plasma lathosterol:cholesterol ratio ( r =-0.366); the campesterol:cholesterol ratio was also positively correlated with the remnant-like emulsion FCR ( r =0.398, P <0.05). In multiple regression analysis, the significant correlations between plasma campesterol:cholesterol ratio and plasma triacylglycerols, RLP-C, apoB-48 and FCR of the remnant-like emulsion were independent of age, dietary energy and plasma lathosterol. Our findings suggest that in subjects with the MS alterations in cholesterol absorption and synthesis may be closely linked with the kinetic defects in TRL metabolism.

Topics: Apolipoprotein B-48; Apolipoproteins B; Biomarkers; Breath Tests; Case-Control Studies; Cholesterol; Humans; Linear Models; Lipoproteins; Male; Metabolic Syndrome; Middle Aged; Phytosterols; Triglycerides

To evaluate both efficacy and safety in humans of long-term consumption of spreads containing plant sterol esters.. Randomized double-blind placebo-controlled parallel trial.. : Hundred and eighty-five healthy volunteers (35-64 y).. Volunteers daily consumed 20 g spread enriched with 1.6 g plant sterols as fatty acid esters or a control spread for 1 y. They continued their habitual diet and lifestyle. Outcome measures included efficacy markers such as total and LDL-cholesterol, a large range of safety parameters, and reporting of adverse events.. Consumption of the plant sterol ester-enriched spread consistently lowered total and LDL cholesterol during the 1 y period on average by 4 and 6%, respectively (0.01 < P < 0.05). Plant sterols intake did on average not result in a lower carotenoid concentration (when expressed per LDL-cholesterol) after 52 weeks (P>0.05). However, carotenoid concentrations changed over time. Plant sterols intake reduced lipid adjusted alpha- and beta-carotene-concentrations by only 15-25% after 1 y, relative to control. Lipid-adjusted fat-soluble vitamin concentrations remained unchanged. Plant sterol concentrations in serum were increased from 2.76 to 5.31 ( micro mol/mmol total cholesterol) for campesterol (P<0.0001) and from 1.86 to 2.47 ( micro mol/mmol total cholesterol) for beta-sitosterol (P<0.0001). The increase in total plant sterol concentration in red blood cells (5.29-9.62 micro g/g) did not affect red blood cell deformability. Hormone levels in males (free and total testosterone) and females (luteinizing hormone, follicle stimulating hormone, beta-estradiol and progesterone) as well as all clinical chemical and hematological parameters measured were unaffected. Adverse events reported were not different between subjects consuming control spread and subjects consuming plant sterol esters-enriched spread.. Consumption of a plant sterol esters-enriched spread is an effective way to consistently lower blood cholesterol concentrations and is safe to use over a long period of time.

Topics: Adult; beta Carotene; Carotenoids; Cholesterol; Cholesterol, LDL; Diet; Dietary Fats; Double-Blind Method; Esters; Female; Humans; Male; Margarine; Middle Aged; Phytosterols; Placebos; Sitosterols

We aimed to study the effect of atorvastatin, a statin, on cholesterol synthesis and absorption and VLDL-apoB metabolism in obese men with the metabolic syndrome.. A total of 25 dyslipidaemic obese men were randomized to atorvastatin (n=13) (40 mg/day) or matching placebo (n=12) for 6 weeks. Hepatic secretion and fractional catabolic rate (FCR) of VLDL-apoB was measured using an intravenous bolus of d(3)-leucine before and after treatment. ApoB isotopic enrichment was measured using GCMS and multicompartmental modelling. Plasma lathosterol: cholesterol and campesterol:cholesterol ratios were determined to assess cholesterol synthesis and cholesterol absorption, respectively.. Compared with placebo, atorvastatin significantly decreased (P<0.05) total cholesterol, triglyceride, LDL-cholesterol and VLDL-apoB. Plasma lathosterol:cholesterol ratio decreased from 26.4+/-2.4 to 8.8+/-0.8, while the campesterol:cholesterol ratio increased from 26.5+/-4.4 to 38.6+/-5.8 (P<0.01). Atorvastatin also increased VLDL-apoB FCR from 3.82+/-0.33 to 6.30+/-0.75 pools/day (P<0.01), but did not significantly alter VLDL-apoB secretion (12.8+/-1.7 to 13.8+/-2.0 mg/kg/day).. In obesity, atorvastatin inhibits cholesterogenesis but increases intestinal cholesterol absorption. The increased cholesterol absorption may counteract the inhibitory effect on hepatic VLDL-apoB secretion, but it does not apparently influence enhanced catabolism of VLDL-apoB.

Topics: Anticholesteremic Agents; Apolipoprotein B-100; Apolipoproteins B; Atorvastatin; Cholesterol; Cholesterol, VLDL; Double-Blind Method; Heptanoic Acids; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Male; Metabolic Syndrome; Middle Aged; Phytosterols; Pyrroles

In a randomized, double-blind, placebo-controlled trial we evaluated the effect of dietary chocolates enriched with a wood-based phytosterol-phytostanol mixture, containing 18 % (w/w) sitostanol, compared with placebo dietary chocolates in seventy subjects with primary hypercholesterolaemia (total cholesterol levels below 8 mmol/l). For 4 weeks, participants consumed three servings of the phytosterol-enriched chocolate/d that provided 1.8 g unesterified phytosterols/d or a placebo chocolate in conjunction with a low-fat, low-cholesterol diet. Plasma total and LDL-cholesterol levels were statistically significantly reduced by 6.4 % (-0.44 mmol/l) and 10.3 % (-0.49 mmol/l), respectively, after 4 weeks of phytosterol-enriched-chocolate treatment. Plasma HDL-cholesterol and triacylglycerol levels were not affected. Consumption of phytosterol-enriched chocolates significantly increased plasma lathosterol concentration (+20.7 %), reflecting an increased endogenous cholesterol synthesis in response to phytosterol-induced decreased intestinal cholesterol absorption. Furthermore, the chocolates enriched with phytosterols significantly increased both plasma sitosterol (+95.8 %) and campesterol (+64.1 %) levels, compared with the placebo chocolate group. However, the absolute values of plasma sitosterol and campesterol remained within the normal range, that is, below 10 mg/l. The chocolates with phytosterols were palatable and induced no clinical or biochemical side effects. These findings indicate that dietary chocolate enriched with tall oil-derived phytosterols (1.8 g/d) is effective in lowering blood total and LDL-cholesterol levels in subjects with mild hypercholesterolaemia and thus may be helpful in reducing the risk of CHD in these individuals.

Topics: Adult; Apolipoproteins B; Cacao; Chi-Square Distribution; Cholesterol; Cholesterol, LDL; Double-Blind Method; Female; Humans; Hypercholesterolemia; Lipids; Male; Middle Aged; Phytosterols; Plant Oils; Sitosterols; Statistics, Nonparametric

Recently identified ABCG5/8 transporters are responsible in part for the different absorption rates of campesterol, sitosterol, and cholesterol. These transporters are also expressed in the liver and might regulate biliary sterol secretion.. This study was therefore conducted to determine the biliary secretion rates and hepatic clearances of campesterol, sitosterol, and cholesterol.. Six healthy, male volunteers.. Deuterium labelled sitosterol and campesterol, and unlabelled sitostanol were constantly infused together with a liquid formula using a duodenal perfusion technique. Biliary secretion and hepatic clearance rates were calculated from hourly bile and plasma samples.. Plasma concentrations of cholesterol, campesterol, and sitosterol averaged 167.5 (50) mg/dl (SD), 0.50 (0.22) mg/dl, and 0.30 (0.10) mg/dl, respectively. Sitosterol showed a significantly higher biliary secretion rate (1.23 (0.87) mg/h) than campesterol (0.76 (0.54) mg/h, p=0.0321), but both plant sterols had significantly lower biliary secretion rates compared with cholesterol (47.7 (17.5) mg/h; p=0.001 for both). Hepatic clearance of cholesterol (0.31 (0.18) dl/h) was significantly lower compared with campesterol (2.11 (2.51) dl/h) and sitosterol (4.97 (4.70) dl/h; p=0.028 for both), and the clearance of campesterol was significant lower compared with sitosterol (p=0.028).. The observed inverse relation between hepatic clearance and known intestinal absorption of cholesterol, campesterol, and sitosterol supports the hypothesis that the ABCG5/8 transporters regulating intestinal sterol absorption might also be involved in biliary sterol excretion.

Topics: Adult; Bile; Cholesterol; Deuterium; Duodenum; Humans; Liver; Male; Metabolic Clearance Rate; Perfusion; Phytosterols; Sitosterols; Statistics, Nonparametric; Sterols

Plant sterols, in various forms, have been shown to reduce total and LDL-cholesterol concentrations. Particularly controversial at present is the effect of the degree of hydrogenation of the plant sterols on cholesterol-lowering efficacy and the responsible mechanisms.. Our goal was to examine the effect of supplementation with unesterified plant sterols and stanols on plasma lipid and phytosterol concentrations and cholesterol absorption, synthesis, and turnover.. Fifteen otherwise healthy hypercholesterolemic subjects consumed each of 4 dietary treatments in a randomized crossover design. Unesterified sterols and stanols were blended into the butter component of the diet at a dosage of 1.8 g/d. The diets contained plant sterols (NS), plant stanols (SS), a 50:50 mixture of sterols and stanols (NSS), or cornstarch (control).. Plasma total cholesterol concentrations were 7.8%, 11.9%, and 13.1% lower (P < 0.01) in the NS, SS, and NSS groups, respectively, than in the control group. LDL-cholesterol concentrations were 11.3%, 13.4%, and 16.0% lower (P < 0.03) in the NS, SS, and NSS groups, respectively, than in the control group. Plasma triacylglycerols and HDL-cholesterol concentrations did not differ significantly across diets. Cholesterol absorption efficiency was 56.0%, 34.4%, and 48.9% lower (P < 0.001) in the NS, SS, and NSS groups, respectively, than in the control group. The fractional synthesis rate was higher by 45.5% (P < 0.003) in the NSS group than in the control group. Plasma campesterol and sitosterol concentrations were higher (P < 0.01) in the NS group and sitosterol concentrations were lower (P < 0.01) in the SS group than in the control group.. These data indicate that, in their free unesterified form, sterols and stanols lower plasma LDL cholesterol equivalently in hypercholesterolemic persons by suppressing cholesterol absorption.

Topics: Adult; Butter; Cholesterol; Cholesterol, LDL; Cross-Over Studies; Diet; Double-Blind Method; Female; Humans; Hypercholesterolemia; Kinetics; Lipids; Male; Middle Aged; Phytosterols; Phytotherapy; Sitosterols

Oil-based products enriched with plant stanol esters can lower low-density lipoprotein (LDL) cholesterol concentrations by 10-14%. Effectiveness of low-fat products, however, has never been evaluated, although such products fit into a healthy diet. We therefore examined the effects of plant stanol esters emulsified into low-fat yoghurt (0.7% fat) on fasting concentrations of plasma lipids and lipid-soluble antioxidants, which may also change by plant stanol consumption. Sixty non-hypercholesterolemic subjects first consumed daily three cups (3 x 150 ml) of placebo yoghurt for 3 weeks. For the next 4 weeks, 30 subjects continued with the placebo yoghurt, while the other 30 subjects received three cups of experimental yoghurt. Each cup provided 1 g of plant stanols (0.71 g sitostanol plus 0.29 g campestanol) as its fatty acid ester. LDL cholesterol (mean+/-S.D.) increased by 0.06+/-0.21 mmol/l in the placebo group, but decreased by -0.34+/-0.30 mmol/l in the experimental group. The difference in changes between the two groups of 0.40 mmol or 13.7% was highly significant (P<0.001; 95% confidence interval for the difference, (-)0.26 -(-)0.53 mmol/l). Effects were already maximal after 1 week. HDL cholesterol and triacylglycerol concentrations did not change. Total tocopherol levels increased by 1.43 micromol/mmol LDL cholesterol (14.0%, P=0.015). beta-carotene levels, however, decreased by -0.02 micromol/mmol LDL cholesterol (-14.4%, P=0.038). Decreases in absolute beta-carotene concentrations were found in all apoB-containing lipoproteins. LDL-cholesterol standardised phytofluene levels decreased by 21.4+/-25.7% (P<0.001), while other plasma carotenoid (lutein/zeaxanthin, beta-cryptoxanthin, lycopene and alpha-carotene) levels did not change significantly. We conclude that low-fat yoghurt enriched with plant stanol esters lowers within 1 week LDL cholesterol to the same extent as oil-based products. LDL-cholesterol standardised concentrations of tocopherol increased. The observed decrease in beta-carotene levels, as found in many other studies, appears not to be limited to the LDL fraction.

Topics: Adolescent; Adult; Aged; Antioxidants; Body Weight; Cholesterol; Diet, Fat-Restricted; Double-Blind Method; Female; Humans; Intestinal Mucosa; Lipids; Lipoproteins; Male; Middle Aged; Netherlands; Phytosterols; Plants; Sitosterols; Solubility; Stigmasterol; Yogurt

Treatment with carbamazepine (CBZ) affects cholesterol concentrations, but little is known about the precise nature and underlying mechanisms of changes in lipoprotein metabolism. We investigated prospectively the effects of CBZ on lipid metabolism in normolipemic adults. In 21 healthy males, lipoprotein and noncholesterol sterol concentrations were measured before and during treatment with CBZ for 70 +/- 18 days. Thirteen subjects underwent kinetic studies of apolipoprotein-B (ApoB) metabolism with the use of endogenous stable isotope labeling. Lipoprotein kinetic parameters were calculated by multicompartmental modeling. Significant increases in total cholesterol, in ApoB-containing lipoproteins [very-low-density lipoprotein (VLDL), intermediate density lipoprotein (IDL), and low-density lipoprotein (LDL)], and in triglycerides, but not in high-density lipoprotein (HDL), were observed. Lipoprotein particle composition remained unchanged. Mean fractional catabolic and production rates of ApoB-containing lipoproteins were not significantly different, although mean production rates of VLDL and IDL were substantially increased (+46 +/- 139% and +30 +/- 97%, respectively), whereas mean production of LDL remained unchanged (+2.1 +/- 45.6%). Cholestanol in serum increased significantly but not the concentrations of plant sterols (campesterol, sitosterol) and the cholesterol precursors (lathosterol, mevalonic acid). There was a significant correlation between the decrease in free thyroxine and the increase in IDL cholesterol. Treatment with CBZ increases mainly ApoB-containing lipoproteins. CBZ seems not to influence endogenous cholesterol synthesis or intestinal absorption directly. The increase is neither related to increased ApoB production nor to decreased catabolism but is rather due to changes in the conversion cascade of IDL particles, most likely as an indirect effect through a decrease in thyroid hormones.

Topics: Adult; Anticonvulsants; Arteriosclerosis; Body Composition; Body Weight; Carbamazepine; Cholestanol; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Cholesterol, VLDL; Diet; Humans; Hydrocortisone; Intestinal Absorption; Lipoproteins; Male; Mevalonic Acid; Phytosterols; Sitosterols

Our objective was to measure the systemic absorption of lecithin-emulsified Delta(5)-phytosterols and phytostanols during test meals by use of dual stable isotopic tracers. Ten healthy subjects underwent two single-meal absorption tests in random order 2 wk apart, one with intravenous dideuterated Delta(5)-phytosterols and oral pentadeuterated Delta(5)-phytosterols and the other with the corresponding labeled stanols. The oral-to-intravenous tracer ratio in plasma, a reflection of absorption, was measured by a sensitive negative ion mass spectroscopic technique and became constant after 2 days. Absorption from 600 mg of Delta(5)-soy sterols given with a standard test breakfast was 0.512 +/- 0.038% for sitosterol and 1.89 +/- 0.27% for campesterol. The absorption from 600 mg of soy stanols was 0.0441 +/- 0.004% for sitostanol and 0.155 +/- 0.017% for campestanol. Reduction of the double bond at position 5 decreased absorption by 90%. Plasma t(1/2) for stanols was significantly shorter than that for Delta(5)-sterols. We conclude that the efficiency of phytosterol absorption is lower than what was reported previously and is critically dependent on the structure of both sterol nucleus and side chain.

Topics: Adult; Cholesterol; Cross-Over Studies; Deuterium; Female; Glycine max; Half-Life; Humans; Intestinal Absorption; Kinetics; Male; Middle Aged; Phytosterols; Sitosterols

Properties of the intestinal digestion of the dietary phytosterols, cholesterol and cholestanol, and the mechanisms by which phytosterols inhibit the intestinal absorption of cholesterol in healthy human subjects are poorly known. We have studied the hydrolysis of dietary plant sterol and stanol esters and their subsequent micellar solubilization by determining their concentrations in micellar and oil phases of the jejunal contents. Two liquid formulas with low (formula 1) and high (formula 2) plant stanol concentrations were infused via a nasogastric tube to the descending duodenum of 8 healthy human subjects, and intestinal contents were sampled for gas-liquid chromatographic sterol analysis 60 cm more distally. During the duodenal transit, phytosterol esters were hydrolyzed. This was especially profound for sitostanol, as its esterified fraction per milligram of sitosterol decreased 80% (P < 0.001) in formula 1 and 61% (P < 0.001) in formula 2. Contrary to that, esterified fraction of cholesterol per milligram of sitosterol was increased fourfold (P < 0.001) in formula 1 and almost sixfold (P < 0.001) in formula 2, whereas that of cholestanol remained unchanged. Percentages of esterified sterols and stanols in total intestinal fluid samples were higher after the administration of formula 2 than of formula 1. Esterified cholesterol and stanols accumulated in the oil phase, and free stanols replaced cholesterol in the micellar phase. At high intestinal plant stanol concentrations, cholesterol looses its micellar solubility possibly by replacement of its free fraction in the micellar phase by hydrolyzed plant stanols, which leads to a decreased intestinal absorption of cholesterol.

Topics: Cholesterol; Cholesterol, Dietary; Esters; Female; Humans; Hydrolysis; Hypolipidemic Agents; Intestinal Absorption; Jejunum; Male; Micelles; Phytosterols; Sitosterols

Ratios of cholestanol, campesterol, and sitosterol to cholesterol in serum are known to reflect cholesterol absorption efficiency. Here, a possible link between these ratios and biliary secretion rates of cholesterol was investigated. Biliary lipid secretion rates and serum sterols were determined in 13 patients with gallstones. Seven were treated with ursodeoxycholic acid (UDCA) (1,000 mg/d). Serum cholesterol and non-cholesterol sterols were also measured in a cross over study in 20 healthy volunteers, who received either placebo or UDCA (750 mg/d). Biliary cholesterol secretion was significantly lower, whereas the non-cholesterol sterols and their ratio to cholesterol were higher in patients with gallstones treated with UDCA. A highly significant negative linear correlation between the ratios of non-cholesterol sterols to cholesterol and biliary cholesterol secretion was observed. In volunteers, administration of UDCA for 4 weeks was followed by a significant increase in non-cholesterol sterols and their ratios. Even 4 weeks after discontinuing UDCA administration, campesterol and sitosterol were still significantly higher than pretreatment levels, which was also true for the campesterol-cholesterol ratio after 8 weeks. The results suggest that the ratios of cholestanol, campesterol, and sitosterol to cholesterol can be used as indicators of changes in biliary cholesterol secretion rates.

Topics: Adult; Bile; Cholagogues and Choleretics; Cholesterol; Female; Humans; Male; Middle Aged; Phytosterols; Sitosterols; Ursodeoxycholic Acid

The effects of a strict uncooked vegan diet on serum lipid and sterol concentrations were studied in patients with rheumatoid arthritis. The subjects were randomized into a vegan diet group (n 16), who consumed a vegan diet for 2-3 months, or into a control group (n 13), who continued their usual omnivorous diets. Serum total and LDL-cholesterol and -phospholipid concentrations were significantly decreased by the vegan diet. The levels of serum cholestanol and lathosterol also decreased, but serum cholestanol:total cholesterol and lathosterol:total cholesterol did not change. The effect of a vegan diet on serum plant sterols was divergent as the concentration of campesterol decreased while that of sitosterol increased. This effect resulted in a significantly greater sitosterol:campesterol value in the vegan diet group than in the control group (1.48 (SD 0.39) v. 0.72 (SD 0.14); P < 0.001). A higher concentration of campesterol compared with sitosterol is normal in omnivorous subjects and can be explained by lower absorption and esterification rates of sitosterol. Our results suggest that a strict uncooked vegan diet changes the relative absorption rates of these sterols and/or their biliary clearance.

Topics: Arthritis, Rheumatoid; Cholestanol; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Diet, Vegetarian; Female; Humans; Middle Aged; Phospholipids; Phytosterols; Sitosterols; Statistics, Nonparametric; Sterols

Plant sterol supplementation reduces serum cholesterol concentration but may increase serum plant sterol concentrations, especially in children. We determined whether natural dietary plant sterols derived mainly from vegetable oil or margarine in early childhood affect serum concentrations of plant sterols (campesterol and sitosterol) and cholesterol precursor sterols (Delta-8 cholestenol, desmosterol, and lathosterol), reflecting endogenous cholesterol synthesis. We measured the serum sterol concentrations using gas liquid chromatography in 20 healthy 13-mo-old intervention children in a randomized, prospective study designed to decrease exposure of the children to known environmental atherosclerosis risk factors and in 20 control children. The diet of the intervention children was rich in plant sterols due to replacement of milk fat with vegetable fat, whereas the diet of the control children contained only small amounts of plant sterols. The intervention children consumed twice as much plant sterols as the control children (P < 0.001). Their serum concentrations of campesterol and sitosterol were 75% and 44% higher, respectively, than those in the control children (P < 0.001 for both), but serum cholesterol precursor sterol concentrations did not differ between the two groups. We conclude that doubling dietary plant sterol intake almost doubles serum plant sterol concentrations in 13-mo-old children, but has no effect on endogenous cholesterol synthesis. Relative intestinal absorption of natural plant sterols from the diet in early childhood is similar to that in adults.

Topics: Arteriosclerosis; Case-Control Studies; Cholesterol; Chromatography, Gas; Desmosterol; Diet Records; Female; Humans; Hypolipidemic Agents; Infant; Intestinal Absorption; Male; Margarine; Phytosterols; Plant Oils; Prospective Studies; Risk Factors; Sitosterols

This study was performed to investigate the difference in the serum-cholesterol- and triglyceride-lowering activities between phytosterols dissolved in diacylglycerol (PS/DG) and dispersed in triacylglycerol (PS/TG). The effects of the solvent on the concentrations of serum beta-sitosterol and campesterol were examined.. The study had a randomised crossover design.. Twelve healthy normocholesterolemic or moderately hypercholesterolemic men aged 29-50 y participated in this study.. For 2 weeks before the test period (designated as the control period), all subjects consumed control mayonnaise (PS free) daily with supper and were randomly assigned to two groups for the 2 week test period; one group was given mayonnaise containing PS (500 mg/day) dissolved in DG (10 g/day), and the other mayonnaise containing PS (500 mg/day) dispersed in TG (10 g/day). After a wash out period consuming control PS-free mayonnaise for 4 weeks, the groups were reversed for 2 weeks.. PS/TG feeding had no effect on the serum cholesterol level. In contrast, PS/DG feeding significantly reduced the total and LDL cholesterol levels from the initial value of 5.57 to 5.31 mmol/l (4.7%; P<0.05) and from 3.69 to 3.39 mmol/l (7.6%; P<0.05), respectively. Moreover, the degree of total cholesterol reduction induced by PS/DG feeding in the test period was significantly greater than that induced by PS/TG feeding (P<0.05). In addition, the serum beta-sitosterol and campesterol concentrations did not change during the PS/TG or PS/DG feeding periods.. Dissolution of PS in DG had a better serum cholesterol lowering effect than dissolution in TG.. Kao Corporation.

Topics: Adult; Cholesterol; Cholesterol, LDL; Cross-Over Studies; Diglycerides; Humans; Hypercholesterolemia; Male; Middle Aged; Phytosterols; Sitosterols; Solubility; Triglycerides

Coronary patients with low baseline ratios of serum cholestanol and plant sterols to cholesterol (indicating low cholesterol absorption) but not those with high ratios (high absorption) experienced reduced recurrences of coronary events during simvastatin treatment in the Scandinavian Simvastatin Survival Study. Thus, in the present study, serum cholesterol, its precursor sterols (reflecting cholesterol synthesis), plant sterols (campesterol and sitosterol), and cholestanol were measured before and during a 5-year period of placebo treatment (n=433) and simvastatin treatment (n=434) in patients from a subgroup of the Scandinavian Simvastatin Survival Study to determine whether changes in cholesterol synthesis and serum levels were related to cholesterol absorption. Serum cholesterol level was unchanged, the ratios of cholesterol precursor sterols to cholesterol were decreased, and the ratios of plant sterols to cholesterol were increased in relation to increasing baseline ratios of cholestanol quartiles. The latter predicted 5-year ratios and simvastatin-induced reductions of the precursor sterols, with the lowering of the ratios (cholesterol synthesis reduction) being almost twice higher in the lowest versus the highest quartile. The ratios of plant sterols, especially campesterol, to cholesterol were markedly increased during simvastatin treatment, mostly in subjects with the highest baseline cholestanol quartiles. Simvastatin reduced serum cholesterol more (P=0.003) in the lowest versus the highest cholestanol quartile during the 5-year treatment period. The results show for the first time that baseline cholesterol metabolism, measured by serum noncholesterol sterols, predicts the effectiveness of simvastatin in reducing cholesterol synthesis and serum levels of cholesterol. The drug suppresses the synthesis of cholesterol markedly more effectively in subjects with high than with low baseline synthesis but reduces respective serum cholesterol levels less markedly than synthesis. Subjects with high cholesterol absorption and low synthesis may need a combination therapy to lower more effectively their serum cholesterol levels and prevent an increase in the levels of plant sterols.

Topics: Anticholesteremic Agents; Body Weight; Cholestanol; Cholesterol; Coronary Disease; Desmosterol; Humans; Phytosterols; Placebos; Simvastatin; Sitosterols; Sterols

To investigate cholesterol-lowering effects of stanol ester (STAEST) and sterol ester (STEEST)-enriched margarines as part of a low-fat diet.. According to a Latin square model randomized double-blind repeated measures design with three test margarines and three periods.. Outpatient clinical trial with free-living subjects.. Thirty-four hypercholesterolaemic subjects completed the study.. Subjects consumed three rapeseed oil-based test margarines (STAEST, STEEST and control (no added stanols or sterols)) as part of a low-fat diet each for 4 weeks.. Mean daily intake of total plant sterols plus stanols was 2.01-2.04 g during the two test margarine periods. In reference to control, serum total cholesterol was reduced by 9.2 and 7.3% with the STAEST and STEEST margarine, respectively (P<0.001 for both). The respective reductions for low-density lipoprotein (LDL) cholesterol were 12.7 and 10.4% (P<0. 001). The cholesterol-lowering effects of the test margarines did not differ significantly. The presence of apolipoprotein E4 allele had a significant effect on LDL cholesterol response during the STAEST margarine only. Serum sitosterol and campesterol increased by 0.83 and 2.77 mg/l with the STEEST (P<0.001), respectively and decreased by 1.18 and 2.60 mg/l with the STAEST margarine (P<0.001). Increases of serum sitostanol and campestanol were 0.11 and 0.19 mg/l with the STAEST margarine (P<0.001), repsectively. No significant changes were found in serum fat-soluble vitamin and carotenoid concentrations when related to serum total cholesterol.. STAEST and STEEST margarines reduced significantly and equally serum total and LDL cholesterol concentrations as part of a low-fat diet.. Grant to the University of Kuopio by Raisio Benecol Ltd, Raisio, Finland.

Topics: Adult; Aged; Anticholesteremic Agents; Antioxidants; Carotenoids; Cholesterol; Diet, Fat-Restricted; Double-Blind Method; Esters; Female; Humans; Hypercholesterolemia; Male; Margarine; Middle Aged; Phytosterols; Plant Oils; Sitosterols; Vitamin E

We investigated the changes of cholesterol and non-cholesterol sterol metabolism during plant stanol ester margarine feeding in 153 hypercholesterolemic subjects. Rapeseed oil (canola oil) margarine without (n = 51) and with (n = 102) stanol (2 or 3 g/day) ester was used for 1 year. Serum sterols were analyzed with gas-liquid chromatography. The latter showed a small increase in sitostanol peak during stanol ester margarine eating. Cholestanol, campesterol, and sitosterol proportions to cholesterol were significantly reduced by 5-39% (P < 0.05 or less for all) by stanol esters; the higher their baseline proportions the higher were their reductions. The precursor sterol proportions were significantly increased by 10- 46%, and their high baseline levels predicted low reduction of serum cholesterol. The decrease of the scheduled stanol dose from 3 to 2 g/day after 6-month feeding increased serum cholesterol by 5% (P < 0. 001) and serum plant sterol proportions by 8-13% (P < 0.001), but had no consistent effect on precursor sterols. In twelve subjects, the 12-month level of LDL cholesterol exceeded that of baseline; the non-cholesterol sterol proportions suggested that stimulated synthesis with relatively weak absorption inhibition contributed to the non-responsiveness of these subjects. In conclusion, plant stanol ester feeding lowers serum cholesterol in about 88% of subjects, decreases the non-cholesterol sterols that reflect cholesterol absorption, increases the sterols that reflect cholesterol synthesis, but also slightly increases serum plant stanols. Low synthesis and high absorption efficiency of cholesterol results in the greatest benefit from stanol ester consumption.

Topics: Anticholesteremic Agents; Body Mass Index; Cholestanol; Cholesterol; Dietary Fats, Unsaturated; Esters; Fatty Acids, Monounsaturated; Humans; Hypercholesterolemia; Kinetics; Margarine; Phytosterols; Rapeseed Oil; Sitosterols; Sterols

Dietary plant sterols (phytosterols) have been shown to lower plasma lipid concentrations in animals and humans. However, the effect of phytosterol intake from tall oil on cholesterol and phytosterol metabolism has not been assessed in subjects fed precisely controlled diets.. Our objective was to examine the effects of sitostanol-containing phytosterols on plasma lipid and phytosterol concentrations and de novo cholesterol synthesis rate in the context of a controlled diet.. Thirty-two hypercholesterolemic men were fed either a diet of prepared foods alone or a diet containing 1.7 g phytosterols/d for 30 d in a parallel study design.. No overall effects of diet on total cholesterol concentrations were observed, although concentrations were lower with the phytosterol-enriched than with the control diet on day 30 (P < 0.05). LDL-cholesterol concentrations on day 30 had decreased by 8.9% (P < 0.01) and 24.4% (P < 0.001) with the control and phytosterol-enriched diets, respectively. HDL-cholesterol and triacylglycerol concentrations did not change significantly. Moreover, changes in circulating campesterol and beta-sitosterol concentrations were not significantly different between phytosterol-fed and control subjects. In addition, there were no significant differences in fractional (0.091 +/- 0.028 and 0.091 +/- 0.026 pool/d, respectively) or absolute (0.61 +/- 0.24 and 0.65 +/- 0.23 g/d, respectively) synthesis rates of cholesterol observed between control and phytosterol-fed subjects.. Addition of blended phytosterols to a prudent North American diet improved plasma LDL-cholesterol concentrations by mechanisms that did not result in significant changes in endogenous cholesterol synthesis in hypercholesterolemic men.

Topics: Adult; Anticholesteremic Agents; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Chromatography, Gas; Humans; Hyperlipidemias; Male; Middle Aged; Phytosterols; Sitosterols; Triglycerides

To determine the efficacy of stanol esters in lowering cholesterol in a US population.. After a run-in phase, 318 subjects were randomized to receive one of the following margarine-like spreads containing stanol ester or placebo for 8 weeks: EU 3 G: 1 g of stanol (ester form) per 8-g serving of a European formula 3 times a day; US 3 G: 1 g of stanol (ester form) per 8-g serving of a US reformulation 3 times a day; US 2 G: 0.67 g of stanol (ester form) per 8-g serving of a US reformulation 3 times a day; or placebo spread.. Mean +/- SD baseline total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels were 233+/-20 and 153+21 mg+/-dL, respectively. In the US 3 G group, 3 g daily of stanol esters lowered TC and LDL-C levels by 6.4% and 10.1%, respectively. There was a dose-dependent response compared with 2 g daily (US 2 G). Triglyceride and high-density lipoprotein cholesterol levels were unchanged. The incidence of adverse effects was not different from placebo. Serum vitamin A and 25-hydroxyvitamin D levels were not affected.. Stanol esters lowered TC and LDL-C levels in a mildly hypercholesterolemic US population without evidence of adverse effects. It may be a useful dietary adjunct to lower cholesterol.

Topics: Adult; Anticholesteremic Agents; beta Carotene; Cholestanols; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Dietary Fats; Dose-Response Relationship, Drug; Double-Blind Method; Esters; Female; Humans; Hypercholesterolemia; Male; Middle Aged; Phytosterols; Sitosterols; Treatment Outcome; Triglycerides; United States; Vitamin A; Vitamin D

To compare effects on plasma total-, LDL-, and HDL-cholesterol concentrations of margarines enriched with different vegetable oil sterols or sitostanol-ester.. A randomized double-blind placebo-controlled balanced incomplete Latin square design with five treatments and four periods of 3.5 weeks. Margarines enriched with sterols from soybean, sheanut or ricebran oil or with sitostanol-ester were compared to a non-enriched control margarine. Sterol intake was between 1.5-3.3 g/d. Two thirds of the soybean oil sterols were esterified to fatty acids.. Unilever Research Laboratory, Vlaardingen, The Netherlands.. One hundred healthy non-obese normocholesterolaemic and mildly hypercholesterolaemic volunteers aged 45+/-12.8 y, with plasma total cholesterol levels below 8 mmol/L at entry.. Plasma lipid, carotenoid and sterol concentrations, blood clinical chemistry and haematology, fatty acid composition of plasma cholesterylesters and food intake.. Ninety-five volunteers completed the study. None of the margarines induced adverse changes in blood clinical chemistry, serum total bile acids or haematology. Plasma total- and LDL-cholesterol concentrations were significantly reduced by 8-13% (0.37-0.44 mmol/L) compared to control for margarines enriched in soybean oil sterol-esters or sitostanol-ester. No effect on HDL-cholesterol concentrations occurred. The LDL- to HDL-cholesterol ratio was reduced by 0.37 and 0.33 units for these margarines, respectively. Effects on blood lipids did not differ between normocholesterolaemic and mildly hypercholesterolaemic subjects. Plasma sitosterol and campesterol levels were significantly higher for the soybean oil sterol margarine and significantly lower for the sitostanol-ester margarine compared to control. Dietary intake was very similar across treatments. The fatty acid composition of plasma cholesterylesters confirmed the good compliance to the treatment. All sterol enriched margarines reduced lipid-standardized plasma alpha- plus beta-carotene levels. Plasma lycopene levels were also reduced but this effect was not significant for all products.. A margarine with sterol-esters from soybean oil, mainly esters from sitosterol, campesterol and stigmasterol, is as effective as a margarine with sitostanol-ester in lowering blood total- and LDL-cholesterol levels without affecting HDL-cholesterol concentrations. Incorporation in edible fat containing products of such substances may substantially reduce the risk of cardiovascular disease in the population.

Topics: Adult; Carotenoids; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Dietary Fats, Unsaturated; Double-Blind Method; Humans; Hypercholesterolemia; Margarine; Middle Aged; Phytosterols; Placebos; Plant Oils; Sitosterols; Soybean Oil

Our aim was to investigate whether intestinal binding of bile acids by guar gum, a dietary fibre, relieves cholestasis and pruritus in intrahepatic cholestasis of pregnancy.. Forty-eight pregnant women with cholestasis and pruritus were randomized double-blind to guar gum and placebo until the time of delivery, and 20 healthy pregnant women were used as control subjects. The pruritus score and serum bile acids, lipids and non-cholesterol sterols were measured at baseline, at least 2 weeks after treatment, just before delivery and up to 4 weeks after delivery.. The increase in serum bile acids and worsening of pruritus were prevented by guar gum in relation to placebo (P < 0.05). Serum cholesterol was unchanged, but increased cholesterol precursor sterol values suggested that cholesterol synthesis was increased by guar gum. Serum cholestanol proportion, an indicator of cholestasis, was related to pruritus but was unaffected by guar gum.. We conclude that in intrahepatic cholestasis of pregnancy and pruritus, guar gum treatment is beneficial in relieving pruritus, even although indicators of cholestasis are only partially reduced.

Topics: Administration, Oral; Adult; Cholestanol; Cholestasis, Intrahepatic; Cholesterol; Desmosterol; Dietary Fiber; Double-Blind Method; Female; Galactans; Humans; Mannans; Phytosterols; Plant Gums; Pregnancy; Pregnancy Complications; Pruritus; Random Allocation; Sitosterols

Reduced cholesterol synthesis has been reported in patients with primary biliary cirrhosis but no data are available on changes in cholesterol catabolism induced by the disease. Serum levels of 7alpha-hydroxycholesterol and 27-hydroxycholesterol have been measured in 25 patients (either normocholesterolemic or hypercholesterolemic) with primary biliary cirrhosis and in control subjects. To evaluate cholesterol synthesis, serum levels of lathosterol were measured, and campesterol and sitosterol were considered to reflect intestinal absorption and biliary elimination of sterols. In normocholesterolemic patients with primary biliary cirrhosis, lathosterol was significantly lower than in normocholesterolemic controls (P < 0.05) whereas no difference was found between hypercholesterolemic patients and hypercholesterolemic controls. Serum concentrations of sitosterol were significantly higher in both normocholesterolemic and hypercholesterolemic patients with primary biliary cirrhosis as compared with the respective controls (P < 0.01). In patients with primary biliary cirrhosis, serum 7alpha-hydroxycholesterol was slightly higher than in controls. 27-Hydroxycholesterol was significantly higher in hypercholesterolemic compared to normocholesterolemic controls (P < 0.05) and a significant linear correlation (r = 0.771; P < 0.001) was found between 27-hydroxycholesterol and cholesterol. In contrast, in patients with primary biliary cirrhosis, high cholesterol concentrations were not associated with increased serum levels of 27-hydroxycholesterol. Our data confirm that in patients with primary biliary cirrhosis, cholesterol synthesis and biliary elimination of sterols are impaired and also suggest that both the feedback regulation of retained bile acids on cholesterol 7alpha-hydroxylase and the scavenger effect on elevated serum cholesterol by cholesterol 27-hydroxylase are deficient in these patients. acids via the acidic pathway.

Topics: Aged; Bile Acids and Salts; Cholesterol; Female; Humans; Hydroxycholesterols; Intestinal Absorption; Liver Cirrhosis, Biliary; Male; Middle Aged; Phytosterols; Sitosterols

Dietary fibre has been suggested to interfere with endogenous cholesterol synthesis in the liver. Therefore the effects of oat bran on the proportions of cholesterol synthesis precursors (squalene, delta(8-) cholesterol, desmosterol and lathosterol), cholestanol and plant sterols (campesterol and beta-sitosterol) to cholesterol were analysed in serum of 36 hypercholesterolaemic subjects.. A randomized study of eight weeks duration when beta-glucan-rich oat bran (n = 20, subjects) or wheat bran (n = 16) was used as a part of a cholesterol lowering diet. Plant sterols and cholesterol synthesis precursors were analysed from frozen samples afterward.. In the oat-bran group, but not in the wheat bran group, serum total cholesterol declined transiently. The proportions of plant sterols and cholesterol in serum, which reflect cholesterol absorption efficiency were unchanged. However, the proportions of squalene appeared to be transiently increased during the study. Subjects with apolipoprotein E 4 allele had higher serum campesterol and sitosterol levels (suggestive of efficient cholesterol absorption) than those with homozygous apolipoprotein E 3 allele.. Since the cholesterol precursors in serum reflecting endogenous cholesterol synthesis remained almost unchanged the reduction in the serum cholesterol level by oat bran treatment can not be ascribed to an inhibition of the endogenous cholesterol synthesis.

Topics: Adult; Alleles; Apolipoprotein E4; Apolipoproteins E; Avena; Cholesterol; Dietary Fiber; Female; Glucans; Humans; Hypercholesterolemia; Male; Middle Aged; Phytosterols; Sitosterols; Squalene

Dietary plant sterols, especially sitostanol, reduce serum cholesterol by inhibiting cholesterol absorption. Soluble sitostanol may be more effective than a less soluble preparation. We tested the tolerability and cholesterol-lowering effect of margarine containing sitostanol ester in a population with mild hypercholesterolemia.. We conducted a one-year, randomized, double-blind study in 153 randomly selected subjects with mild hypercholesterolemia. Fifty-one consumed margarine without sitostanol ester (the control group), and 102 consumed margarine containing sitostanol ester (1.8 or 2.6 g of sitostanol per day).. The margarine containing sitostanol ester was well tolerated. The mean one-year reduction in serum cholesterol was 10.2 percent in the sitostanol group, as compared with an increase of 0.1 percent in the control group. The difference in the change in serum cholesterol concentration between the two groups was -24 mg per deciliter (95 percent confidence interval, -17 to -32; P < 0.001). The respective reductions in low-density lipoprotein (LDL) cholesterol were 14.1 percent in the sitostanol group and 1.1 percent in the control group. The difference in the change in LDL cholesterol concentration between the two groups was -21 mg per deciliter (95 percent confidence interval, -14 to -29; P < 0.001). Neither serum triglyceride nor high-density lipoprotein cholesterol concentrations were affected by sitostanol. Serum campesterol, a dietary plant sterol whose levels reflect cholesterol absorption, was decreased by 36 percent in the sitostanol group, and the reduction was directly correlated with the reduction in total cholesterol (r = 0.57, P < 0.001).. Substituting sitostanol-ester margarine for part of the daily fat intake in subjects with mild hypercholesterolemia was effective in lowering serum total cholesterol and LDL cholesterol.

Topics: Adult; Anticholesteremic Agents; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Dietary Fats; Double-Blind Method; Female; Humans; Hypercholesterolemia; Male; Margarine; Middle Aged; Phytosterols; Sitosterols; Triglycerides

Risk of cardiovascular disease is increased in patients with diabetes mellitus (DM). Cholesterol metabolism (hepatic synthesis and intestinal absorption) is known to be associated with cardiovascular risk. Next, we examined the association of DM with cholesterol absorption/synthesis.. The CACHE Consortium, which is comprised of 13 research groups in Japan possessing data of lathosterol (Latho, synthesis marker) and campesterol (Campe, absorption marker) measured by gas chromatography, compiled the clinical data using the REDCap system. Among the 3597 records, data from 2944 individuals were used for several analyses including this study.. This study analyzed data from eligible 2182 individuals including 830 patients with DM; 42.2% were female, median age was 59 years, and median HbA1c of patients with DM was 7.0%. There was no difference in Latho between DM and non-DM individuals. Campe and Campe/Latho ratio were significantly lower in DM individuals than in non-DM individuals. When the associations of glycemic control markers with these markers were analyzed with multivariable-adjusted regression model using restricted cubic splines, Campe and Campe/Latho ratio showed inverse associations with glucose levels and HbA1c. However, Latho showed an inverted U-shaped association with plasma glucose, whereas Latho showed a U-shaped association with HbA1c. These associations remained even after excluding statin and/or ezetimibe users.. We demonstrated that DM and hyperglycemia were independent factors for lower cholesterol absorption marker levels regardless of statin/ezetimibe use.

Topics: Biomarkers; Cholesterol; Diabetes Mellitus; Ezetimibe; Female; Glycated Hemoglobin; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Male; Middle Aged; Phytosterols

Campesterol is a major phytosterol that plays important roles in regulating membrane properties and serves as the precursor to multiple specialized metabolites, such as the phytohormone brassinosteroids. Recently, we established a campesterol-producing yeast strain and extended the bioproduction to 22-hydroxycampesterol and 22-hydroxycampest-4-en-3-one, the precursors to brassinolide. However, there is a trade-off in growth due to the disrupted sterol metabolism. In this study, we enhanced the growth of the campesterol-producing yeast by partially restoring the activity of the sterol acyltransferase and engineering upstream FPP supply. Furthermore, genome sequencing analysis also revealed a pool of genes possibly associated with the altered sterol metabolism. Retro engineering implies an essential role of ASG1, especially the C-terminal asparagine-rich domain of ASG1, in the sterol metabolism of yeast especially under stress. The performance of the campesterol-producing yeast strain was enhanced with the titer of campesterol to 18.4 mg/L, and the stationary OD

Topics: Phytosterols; Plant Proteins; Saccharomyces cerevisiae

In this study, twelve campesterol derivatives (2-13) were prepared by esterification reaction at the hydroxy group in C-3 and catalytic hydrogenation at the carbon-carbon double bond in C-5(6). All obtained compounds were characterized by IR,

Topics: Anti-Bacterial Agents; Microbial Sensitivity Tests; Molecular Docking Simulation; Phytosterols

We evaluated oxyphytosterol (OPS) concentrations in plasma and various tissues of two genetically modified mouse models with either increased cholesterol (apoE KO mice) or increased cholesterol and plant sterol (PS) concentrations (apoExABCG8 dKO mice). Sixteen female apoE KO and 16 dKO mice followed the same standard, low OPS-chow diet. Animals were euthanized at 36 weeks to measure PS and OPS concentrations in plasma, brain, liver and aortic tissue. Cholesterol and oxysterol (OS) concentrations were analyzed as reference for sterol oxidation in general. Plasma campesterol (24.1 ± 4.3 vs. 11.8 ± 3.0 mg/dL) and sitosterol (67.4 ± 12.7 vs. 4.9 ± 1.1 mg/dL) concentrations were severely elevated in the dKO compared to the apoE KO mice (p < 0.001). Also, in aortic and brain tissue, PS levels were significantly elevated in dKO. However, plasma, aortic and brain OPS concentrations were comparable or even lower in the dKO mice. In contrast, in liver tissue, both PS and OPS concentrations were severely elevated in the dKO compared to apoE KO mice (sum OPS: 7.4 ± 1.6 vs. 4.1 ± 0.8 ng/mg, p < 0.001). OS concentrations followed cholesterol concentrations in plasma and all tissues suggesting ubiquitous oxidation. Despite severely elevated PS concentrations, OPS concentrations were only elevated in liver tissue, suggesting that OPS are primarily formed in the liver and plasma concentrations originate from hepatic spill-over into the circulation.

Topics: Animals; Apolipoproteins E; ATP Binding Cassette Transporter, Subfamily G, Member 8; Cholesterol; Female; Lipid Metabolism; Lipoproteins; Liver; Mice; Mice, Knockout; Oxidation-Reduction; Oxysterols; Phytosterols; Sitosterols

In the present work, a dispersive liquid-liquid microextraction approach has been developed for extraction of four phytosterols (stigmasterol, β-sitosterol, campesterol, and brassicasterol) from cow milk samples using organic and deep eutectic solvents and the results were critically compared. The extracted analytes were determined using high performance liquid chromatography. In the developed method, carbon tetrachloride and choline chloride:p-chlorophenol deep eutectic solvent were selected to use as the best extraction solvent. Effective parameters and validation data were studied for both methods, independently. Under optimum conditions, limits of detection and quantification were within the ranges of 0.3-0.9 and 1.0-3.0 ng/mL for organic solvent based dispersive liquid-liquid microextraction and 0.09-0.32 and 0.3-1.0 ng/mL for deep eutectic solvent based dispersive liquid-liquid microextraction, respectively. Good coefficient of determinations and relative standard deviations obtained for the methods were ≥0.994 and ≤7.6%, respectively. The introduced method was performed on different milk samples for the determination of target analytes using both solvents and the results were analyzed statistically by the t-test.

Topics: Animals; Cholestadienols; Cholesterol; Chromatography, High Pressure Liquid; Deep Eutectic Solvents; Food Contamination; Limit of Detection; Liquid Phase Microextraction; Milk; Pesticide Residues; Phytosterols; Solvents

Plant sterols (PSs) cannot be synthesized in mammals and are exclusively diet-derived. PSs cross the blood-brain barrier and may have anti-neuroinflammatory effects. Obesity is linked to lower intestinal uptake and blood levels of PSs, but its effects in terms of neuroinflammation-if any-remain unknown. We investigated the effect of high-fat diet-induced obesity on PSs in the brain and the effects of the PSs campesterol and β-sitosterol on in vitro microglia activation. Sterols (cholesterol, precursors, PSs) and polyunsaturated fatty acid-derived lipid mediators were measured in the food, blood, liver and brain of C57BL/6J mice. Under a PSs-poor high-fat diet, PSs levels decreased in the blood, liver and brain (>50%). This effect was reversible after 2 weeks upon changing back to a chow diet. Inflammatory thromboxane B2 and prostaglandin D2 were inversely correlated to campesterol and β-sitosterol levels in all brain regions. PSs content was determined post mortem in human cortex samples as well. In vitro, PSs accumulate in lipid rafts isolated from SIM-A9 microglia cell membranes. In summary, PSs levels in the blood, liver and brain were associated directly with PSs food content and inversely with BMI. PSs dampen pro-inflammatory lipid mediators in the brain. The identification of PSs in the human cortex in comparable concentration ranges implies the relevance of our findings for humans.

Topics: Animal Feed; Animals; Cells, Cultured; Cholesterol; Chromatography, Liquid; Diet, High-Fat; Disease Models, Animal; Fatty Acids, Unsaturated; Humans; Lipidomics; Liver; Male; Mice; Mice, Inbred C57BL; Microglia; Neuroinflammatory Diseases; Obesity; Phytosterols; Sitosterols; Tandem Mass Spectrometry

This paper provides a method for the quantification of sterols in different types of calf feedstuffs based on soy, sunflower, hay, calf feed and a mixture of all of them. The free fraction and the total sterolic fraction, after saponification and acidic hydrolysis of the samples, are extracted by solvent and the sterols are identified/quantified by reversed phase HPLC coupled to tandem mass spectrometry by atmospheric pressure chemical ionization. After the recovery evaluation, the method is validated in terms of linearity (coefficient of determination R

Topics: Animal Feed; Animals; Atmospheric Pressure; Cattle; Cholesterol; Chromatography, High Pressure Liquid; Ergosterol; Glycine max; Helianthus; Phytosterols; Sitosterols; Stigmasterol; Tandem Mass Spectrometry

We investigated the main sterols, phytosterols, and the α- and γ-tocopherol content in donkey milk during the first 2 mo of lactation. Cholesterol was the main sterol in milk (mean ± standard deviation = 0.97 ± 0.443 g/100 g of fat). Lanosterol was the main minor sterol of animal origin, followed by desmosterol (0.003 ± 0.001 and 0.001 ± 0.001 g/100 g of fat, respectively). Of the phytosterols, β-sitosterol was the main sterol of vegetal origin in donkey milk (0.005 ± 0.002 g/100 g of fat), but lower levels of campesterol, brassicasterol, and stigmasterol were also recorded. Mean levels of α- and γ-tocopherol were 0.01 ± 0.007 and 0.003 ± 0.001 g/100 g of fat, respectively. We observed no significant changes in sterol or tocopherol content during the first 2 mo of lactation. The presence of lanosterol in donkey milk is of particular interest, because lanosterol is a potential drug and has important physiological effects. The presence of phytosterols, which are considered nutraceutical molecules, enhances the nutritional quality of donkey milk fat for consumers.

Topics: Animals; Cholestadienols; Cholesterol; Desmosterol; Equidae; Female; Lactation; Lanosterol; Milk; Nutritive Value; Phytosterols; Saponins; Sitosterols; Sterols; Tocopherols

Topics: Benzhydryl Compounds; Cholesterol; Cholesterol, HDL; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucosides; Humans; Phytosterols

Several factors could lead to lipid disturbances observed in cystic fibrosis (CF). This study aimed to assess sterol homeostasis in CF and define potential exogenous and endogenous determinants of lipid dysregulation.. The study involved 55 CF patients and 45 healthy subjects (HS). Sterol concentrations (μg/dL) were measured by gas chromatography/mass spectrometry. CF was characterised by lung function, pancreatic status, liver disease and diabetes coexistence,. Independent determinants of lipid status suggest that malabsorption and pancreatic enzyme supplementation play a significant role in sterol abnormalities. The measurement of campesterol and β-sitosterol concentrations in CF patients may serve for the assessment of the effectiveness of pancreatic enzyme replacement therapy and/or compliance, but further research is required.

Topics: Adolescent; Adult; Anthropometry; Cholesterol; Cystic Fibrosis; Enzyme Replacement Therapy; Exocrine Pancreatic Insufficiency; Female; Gas Chromatography-Mass Spectrometry; Genotype; Homeostasis; Humans; Lipids; Male; Middle Aged; Pancreas; Phytosterols; Sitosterols; Sterols; Young Adult

Topics: Benzhydryl Compounds; Cholesterol; Cholesterol, HDL; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Glucosides; Humans; Motivation; Phytosterols; Sodium-Glucose Transporter 2 Inhibitors

Topics: Cannabis; Cholesterol; Hydroponics; Oleanolic Acid; Phytosterols; Plant Extracts; Plant Roots; Sitosterols; Stigmasterol; Triterpenes

The present study was conducted to establish a practical method for measuring non-cholesterol sterols and reference intervals of serum levels.. Healthy subjects (109 men and 151 women), four patients with sitosterolemia, and 10 heterozygous mutation carriers of ABCG5/ABCG8 genes were investigated. Then, three non-cholesterol sterols (sitosterol, campesterol, and lathosterol) of fasting serum samples were measured via a practical and highly sensitive gas chromatography (GC) method with 0.2 µg/mL as the lower limit of quantification. The coefficient of variation (CV) values for within-run reproducibility were 3.06%, 1.89%, and 1.77% for lathosterol, campesterol, and sitosterol, respectively. The CV values for between-run reproducibility were 2.81%, 2.06%, and 2.10% for lathosterol, campesterol, and sitosterol, respectively.. The serum levels of sitosterol and campesterol were significantly higher in women than in men, whereas the serum levels of lathosterol were significantly higher in men than in women. Because of these gender difference, the determination of reference intervals of the three sterol values was performed by considering gender. The reference intervals of sitosterol, campesterol, and lathosterol were 0.99-3.88, 2.14-7.43, and 0.77-3.60 µg/mL in men and 1.03-4.45, 2.19-8.34, and 0.64-2.78 µg/mL in women, respectively. The serum levels of sitosterol and campesterol were higher in patients with sitosterolemia (94.3±47.3 and 66.3±36.6 µg/mL, respectively) than in healthy subjects.. These results demonstrate a practical and highly sensitive GC method to measure non-cholesterol sterol levels and gender-segregated reference intervals of sitosterol, campesterol, and lathosterol in Japanese healthy subjects.

Topics: ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; Cholesterol; Cholesterol, Dietary; Chromatography, Gas; Female; Humans; Hypercholesterolemia; Intestinal Diseases; Japan; Lipid Metabolism, Inborn Errors; Lipoproteins; Male; Middle Aged; Phytosterols; Reference Values; Reproducibility of Results; Sex Factors; Sitosterols

A novel liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed and validated to simultaneously quantify phytosterols (brassicasterol, campesterol, stigmasterol and β-sitosterol) and tocopherols (alpha, beta, gamma and delta) entrapped in the lipid bilayer of a liposomal formulation. Apart from liposomes (a pharmaceutical product), the developed method was able to quantify target analytes in agricultural products, thus showing wide applications. Atmospheric pressure chemical ionization (APCI) was employed due to the enhanced ionization of phytosterols and tocopherols in comparison to electrospray ionization. Unlike published work, the chromatographic conditions were modified to simplify the analytical approach. For the first time, a simple isocratic elution (acetonitrile:methanol 99:1 v/v) was utilized for the separation of four phytosterols and four tocopherols in a single run. A substantially better baseline separation of phytosterols were obtained in comparison to reported methods by using poroshell C18 column. The method has a total run time of 7 min, which is the shortest run time among all reported quantitative methods for the simultaneous determination of four phytosterols and four tocopherols. Calibration curves for all phytosterols were linear in the range of 0.05-10 μg/mL. In the case of tocopherols, alpha tocopherol showed linear response in the range of 0.25-10 μg/mL. However, gamma and delta tocopherols exhibited quadratic relationship in the same concentration range (0.25-10 μg/mL). Validation parameters met the International Conference on Harmonization (ICH) guidelines in terms of selectivity, accuracy, precision, repeatability, sensitivity, matrix effects, dilution integrity and stability. The method was, for the first time, successfully applied for the quantifying phytosterols and tocopherols entrapped inside liposomes. An interesting chromatographic phenomenon was observed during sample analysis. Alpha tocopherol (entrapped in the liposomal lipid bilayer) was found to elute at two retention times, 2.53 min and 3.60 min. Such dual separation was not observed in calibration standards and quality controls. It was concluded that the chiral recognition ability of liposomes made up of phosphatidylcholine separated the enantiomers of alpha tocopherol, giving rise to two peaks at two different retention time. To sum, the reported novel LC-MS/MS method addresses three major analytical shortcomings, namely i)longer run time,

Topics: Atmospheric Pressure; Calibration; Cholestadienols; Cholesterol; Chromatography, High Pressure Liquid; Chromatography, Liquid; Liposomes; Phytosterols; Reproducibility of Results; Sitosterols; Spectrometry, Mass, Electrospray Ionization; Stigmasterol; Tandem Mass Spectrometry; Tocopherols

HepG2 cells were incubated with a 16.5:1.7:1 ratio of cholesterol:sitosterol:campesterol (CSC), a ratio of the major sterols observed in the plasma of phytosterolemia patients, or with cholesterol alone in combination with [

Topics: Carbon Radioisotopes; Cholesterol; Cholesterol Esters; Down-Regulation; Gene Expression Profiling; Gene Expression Regulation; Hep G2 Cells; Humans; Hypercholesterolemia; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Models, Biological; Phytosterols; Receptors, LDL; Sitosterols

Vegetable lipid emulsions (LE) contain non-declared phytosterols (PS). We aimed to determine PS content depending on the brand and LE batch, and in adult hospitalised patients treated with parenteral nutrition (PN), to establish the association between plasma and administered PS. Part I was the LE study: totals and fractions of PS in three to four non-consecutive batches from six LE were analysed. Part II was the patient study: patients with at least 7 previous days of PN with 0·8 g/kg per d of an olive/soyabean (O/S) LE were randomised (day 0) 1:1 to O/S or 100 % fish oil (FO) at a dose of 0·4 g/kg per d for 7 d (day 7). Plasma PS, its fractions, total cholesterol on days 0 and 7, their clearance and their association with PS administered by LE were studied. In part I, LE study: differences were found in the total PS, their fractions and cholesterol among different LE brands and batches. Exclusive soyabean LE had the highest content of PS (422·36 (sd 130·46) μg/ml). In part II, patient study: nineteen patients were included. In the O/S group, PS levels were maintained (1·11 (sd 6·98) μg/ml) from day 0 to 7, while in the FO group, significant decreases were seen in total PS (-6·21 (sd 4·73) μg/ml) and their fractions, except for campesterol and stigmasterol. Plasma PS on day 7 were significantly associated with PS administered (R2 0·443). PS content in different LE brands had great variability. PS administered during PN resulted in accumulation and could be prevented with the exclusive administration of FO LE.

Topics: Adult; Cholesterol; Fat Emulsions, Intravenous; Female; Fish Oils; Humans; Hypercholesterolemia; Inpatients; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Male; Parenteral Nutrition; Parenteral Nutrition Solutions; Phytosterols; Plant Oils; Prospective Studies; Stigmasterol; Vegetables

Topics: Cholesterol; Chromatography, Gas; Food Handling; Phytosterols; Plant Oils; Sitosterols; Stigmasterol; Temperature; Time Factors

Sterols are verified to be able to produce polycyclic aromatic hydrocarbons during its pyrolysis. In this study, a kind of

Topics: Absorption, Physiological; Aspergillus fumigatus; Biodegradation, Environmental; Biomass; Cholesterol; Ergosterol; Hydrogen-Ion Concentration; Microscopy, Electron, Scanning; Nicotiana; Phytosterols; Plant Extracts; Plant Leaves; Sitosterols; Spectroscopy, Fourier Transform Infrared; Stigmasterol; Water Pollutants, Chemical

Chorioamnionitis can lead to inflammation and injury of the liver and gut, thereby predisposing patients to adverse outcomes such as necrotizing enterocolitis (NEC). In addition, intestinal bile acids (BAs) accumulation is causally linked to NEC development. Plant sterols are a promising intervention to prevent NEC development, considering their anti-inflammatory properties in the liver. Therefore, we investigated whether an intra-amniotic (IA)

Topics: Animals; beta-Cyclodextrins; Cholesterol; Chorioamnionitis; Disease Models, Animal; Drug Carriers; Enterocolitis, Necrotizing; Enterohepatic Circulation; Female; Fetus; Inflammation; Injections, Intralesional; Liver; Phytosterols; Phytotherapy; Post-Exposure Prophylaxis; Pregnancy; Sheep; Sitosterols; Ureaplasma; Ureaplasma Infections

Plant seeds have been found to contain bioactive compounds that have potential nutraceutical benefits. Guava seeds (

Topics: Animals; Antioxidants; Carcinoma, Hepatocellular; Cholesterol; Female; Hexanes; Liver Neoplasms; Male; Oxidative Stress; Phenols; Phytosterols; Plant Extracts; Plant Oils; Psidium; Rats; Seeds; Sitosterols; Triglycerides

Topics: Cholesterol; Chromatography, High Pressure Liquid; Flow Injection Analysis; Ion Mobility Spectrometry; Limit of Detection; Mass Spectrometry; Phytosterols; Sitosterols; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

It is controversial whether atherosclerosis is linked to increased intestinal cholesterol absorption or synthesis in humans. The aim of the present study was to relate atherosclerosis to the measurements of plasma markers of cholesterol synthesis (desmosterol, lathosterol) and absorption (campesterol, sitosterol). In healthy male (n=344), non-obese, non-diabetics, belonging to the city of São Paulo branch of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil), we measured in plasma these non-cholesterol sterol markers, together with their anthropometric, dietary parameters, traditional atherosclerotic risk factors, and blood chemistry, coronary arterial calcium score (CAC), and ultrasonographically measured common carotid artery intima-media thickness (CCA-IMT). Cases with CAC>zero had the following parameters higher than cases with CAC = zero: age, waist circumference (WC), plasma total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C), and non-high density lipoprotein-cholesterol (non HDL-C). Plasma desmosterol and campesterol, duly corrected for TC, age, body mass index (BMI), waist circumference (WC), hypertension, smoking, and the homeostasis model assessment-insulin resistance (HOMA-IR) correlated with CAC, but not with CCA-IMT. The latter related to increased age, BMI, waist circumference (WC), and systolic blood pressure (SBP). Plasma HDL-C concentrations did not define CAC or CCA-IMT degrees, although in relation to the lower tertile of HDL-C in plasma the higher tertile of HDL-C had lower HOMA-IR and concentration of a cholesterol synthesis marker (desmosterol). Present work indicated that increased cholesterol synthesis and absorption represent primary causes of CAD, but not of the common carotid artery atherosclerosis.

Topics: Adult; Aged; Atherosclerosis; Biomarkers; Body Mass Index; Brazil; Calcium; Carotid Artery, Common; Carotid Intima-Media Thickness; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Coronary Vessels; Cross-Sectional Studies; Desmosterol; Female; Humans; Intestinal Absorption; Intestinal Mucosa; Longitudinal Studies; Male; Middle Aged; Phytosterols; Prospective Studies; Sitosterols; Tomography, X-Ray Computed; Ultrasonography

Sitosterolemia is caused by homozygous or compound heterozygous gene mutations in either ATP-binding cassette subfamily G member 5 (ABCG5) or 8 (ABCG8). Since ABCG5 and ABCG8 play pivotal roles in the excretion of neutral sterols into feces and bile, patients with sitosterolemia present elevated levels of serum plant sterols and in some cases also hypercholesterolemia. A 48-year-old woman was referred to our hospital for hypercholesterolemia. She had been misdiagnosed with familial hypercholesterolemia at the age of 20 and her serum low-density lipoprotein cholesterol (LDL-C) levels had remained about 200-300 mg/dL at the former clinic. Although the treatment of hydroxymethylglutaryl-CoA (HMG-CoA) reductase inhibitors was ineffective, her serum LDL-C levels were normalized by ezetimibe, a cholesterol transporter inhibitor. We noticed that her serum sitosterol and campesterol levels were relatively high. Targeted analysis sequencing identified a novel heterozygous ABCG5 variant (c.203A>T; p.Ile68Asn) in the patient, whereas no mutations were found in low-density lipoprotein receptor (LDLR), proprotein convertase subtilisin/kexin type 9 (PCSK9), or Niemann-Pick C1-like intracellular cholesterol transporter 1 (NPC1L1). While sitosterolemia is a rare disease, a recent study has reported that the incidence of loss-of-function mutation in the ABCG5 or ABCG8 gene is higher than we thought at 1 in 220 individuals. The present case suggests that serum plant sterol levels should be examined and ezetimibe treatment should be considered in patients with hypercholesterolemia who are resistant to HMG-CoA reductase inhibitors.

Topics: Anticholesteremic Agents; ATP Binding Cassette Transporter, Subfamily G, Member 5; Cholesterol; Cholesterol, LDL; Diagnostic Errors; Ezetimibe; Female; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypercholesterolemia; Hyperlipoproteinemia Type II; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Loss of Function Mutation; Middle Aged; Phytosterols; Sitosterols; Treatment Failure

Changes in cholesterol absorption and cholesterol synthesis may promote dyslipidemia and cardiovascular disease in individuals with type 2 diabetes mellitus (T2DM).. To assess cholesterol synthesis and absorption in lean individuals, obese individuals, and individuals with T2DM.. We measured lathosterol and lanosterol (markers of cholesterol synthesis) as well as campesterol and β-sitosterol (markers of cholesterol absorption) in the serum of 15 to 26 years old individuals with T2DM (n = 95), as well as their lean (n = 98) and obese (n = 92) controls.. Individuals with T2DM showed a 51% increase in lathosterol and a 65% increase in lanosterol compared to lean controls. Similarly, obese individuals showed a 31% increase in lathosterol compared to lean controls. Lathosterol and lanosterol were positively correlated with body mass index, fasting insulin and glucose, serum triglycerides, and C-reactive protein, and negatively correlated with HDL-cholesterol. In contrast, campesterol and β-sitosterol were not altered in individuals with T2DM. Moreover, campesterol and β-sitosterol were negatively correlated with body mass index, fasting insulin, and C-reactive protein and were positively correlated with HDL-cholesterol.. Adolescents and young adults with T2DM show evidence of increased cholesterol synthesis compared to non-diabetic lean controls. These findings suggest that T2DM may promote cardiovascular disease by increasing cholesterol synthesis, and provide additional rationale for the use of cholesterol synthesis inhibitors in this group.

Topics: Adolescent; Adult; Biomarkers; Body Mass Index; Case-Control Studies; Cholesterol; Diabetes Mellitus, Type 2; Humans; Obesity; Phytosterols; Sitosterols; Young Adult

Sitosterolemia is an inherited lipid disorder which presents with elevated serum sitosterol and can result in an increased risk of premature cardiovascular disease. However, sitosterol cannot be accurately measured by routine diagnostic assays, meaning that sitosterolemia diagnosis can often be difficult, especially with many clinical features overlapping with familial hypercholesterolemia. With such complications resulting in increasing reports of misdiagnosis, the prevalence of sitosterolemia is predicted to be much higher than previously reported.. Gas chromatography-mass spectrometry was utilized to measure sitosterol levels of normocholesterolemic and hypercholesterolemic children. Subsequently, an epidemiologically determined cutoff level of sitosterol was calculated and applied to estimate the prevalence of children with increased sitosterol and identify potential sitosterolemia patients. Massively parallel sequencing was used to confirm the diagnosis in suspected patients.. Samples from 109 normocholesterolemic and 220 hypercholesterolemic were tested for phytosterols. Sitosterol and campesterol levels were significantly increased in hypercholesterolemic children (mean 22.0±45.9 μmol/L for sitosterol and 26.0±32.8 μmol/L for campesterol) compared to normocholesterolemic children (mean 12.1±4.9 μmol/L for sistosterol and 14.8±6.7 μmol/L for campesterol). Via application of a cutoff of 35.9 μmol/L, the prevalence rates for increased and overtly increased sitosterol in hypercholesterolemic children were 6.4% and 1.4% respectively. Furthermore, 3 suspected sitosterolemia patients were identified, with 2 patients receiving molecular confirmation for sitosterolemia diagnosis.. Our findings reaffirm that the prevalence of sitosterolemia is probably much higher than previously reported, which also indicates the significant risk of misdiagnosis of sitosterolemia with familial hypercholesterolemia. Special lipid testing including sitosterol, especially in children with uncontrolled hypercholesterolemia, is recommended in children in order to identify potential sitosterolemia patients that would otherwise be neglected.

Topics: Adolescent; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; Child; Child, Preschool; Cholesterol; Female; Gas Chromatography-Mass Spectrometry; Humans; Hypercholesterolemia; Infant; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipoproteins; Male; Pedigree; Phytosterols; Prevalence; Sitosterols

The nutritional composition and chemical properties of the Chinese highland barley bran oil were characterized in this study. The barley bran oil extracted with solvent possessed relatively high acid value and peroxide value, indicating that the oil should be further refined before using. The fatty acid composition of the oil showed that the content of unsaturated fatty acids was 80.12 g/100 g, in which the content of polyunsaturated fatty acids was as high as 60.41 g/100 g. The overall triacylglycerol profile showed that the oil contained 27 TAGs including 21 regioisomers. Major TAGs included LLL (21.08 g/100 g), PLL (19.27 g/100 g), LLO (12.24 g/100 g), and LLLn (12.17 g/100 g). The total unsaponifiable matter of the oil reached up to 10.74 g/100 g oil. The total phytosterol content reached 7.90 g/100 g oil, in which β-sitosterol was the most predominant, with the content of 5.69 g/100 g oil. Other important sterols included campesterol (1.32 g/100 g oil), lanosterol (0.70 g/100 g oil) and stigmasterol (0.19 g/100 g oil).

Topics: China; Cholesterol; Fatty Acids, Unsaturated; Hordeum; Lanosterol; Nutrients; Phytosterols; Plant Oils; Sitosterols; Stigmasterol; Triglycerides

In the current super-aging society, the establishment of methods for prevention and treatment of Alzheimer's disease (AD) is an urgent task. One of the causes of AD is thought to be a decrease in the revel of nerve growth factor (NGF) in the brain. Compounds showing NGF-mimicking activity and NGF-enhancing activity have been examined as possible agents for improving symptoms. In the present study, sunflower seed extract was found to have neurite outgrowth-promoting activity, which is an NGF-enhancing activity, in PC12 cells. To investigate neurite outgrowth-promoting compounds from sunflower seed extract, bioassay-guided purification was carried out. The purified active fraction was obtained by liquid-liquid partition followed by some column chromatographies. Proton nuclear magnetic resonance and gas chromatography-mass spectrometry analyses of the purified active fraction indicated that the fraction was a mixture of β-sitosterol, stigmasterol and campesterol, with β-sitosterol being the main component. Neurite outgrowth-promoting activities of β-sitosterol, stigmasterol, campesterol and cholesterol were evaluated in PC12 cells. β-Sitosterol and stigmasterol showed the strongest activity of the four sterol compounds (β-sitosterol ≈ stigmasterol > campesterol > cholesterol), and cholesterol did not show any activity. The results indicated that β-sitosterol was the major component responsible for the neurite outgrowth-promoting activity of sunflower seeds. Results of immunostaining also showed that promotion by β-sitosterol of neurite formation induced by NGF was accompanied by neurofilament expression. β-Sitosterol, which showed NGF-enhancing activity, might be a candidate ingredient in food for prevention of AD.

Topics: Alzheimer Disease; Animals; Brain; Cholesterol; Gene Expression Regulation; Helianthus; Humans; Nerve Growth Factor; Neurites; Neuronal Outgrowth; PC12 Cells; Phytosterols; Plant Extracts; Rats; Seeds; Sitosterols; Stigmasterol

Cholesterol is an essential component in human development. In fetuses affected by intrauterine growth restriction (IUGR), fetal blood cholesterol levels are low. Whether this is the result of a reduced materno-fetal cholesterol transport, or due to low fetal de novo synthesis rates, remains a matter of debate. By analyzing cholesterol interbolites and plant sterols we aimed at deeper insights into transplacental cholesterol transport and fetal cholesterol handling in IUGR with potential targets for future therapy. We hypothesized that placental insufficiency results in a diminished cholesterol supply to the fetus.. Venous umbilical cord sera were sampled post-partum from fetuses delivered between 24 weeks of gestation and at full term. IUGR fetuses were matched to 49 adequate-for-age delivered preterm and term neonates (CTRL) according to gestational age at delivery. Cholesterol was measured by gas chromatography-flame ionization detection using 5a-cholestane as internal standard. Cholesterol precursors and synthesis markers, such as lanosterol, lathosterol, and desmosterol, the absorption markers, 5α-cholestanol and plant sterols, such as campesterol and sitosterol, as well as enzymatically oxidized cholesterol metabolites (oxysterols), such as 24S- or 27-hydroxycholesterol, were analyzed by gas chromatography-mass spectrometry, using epicoprostanol as internal standard for the non-cholesterol sterols and deuterium labeled oxysterols for 24S- and 27-hydroxycholesterol.. Mean cholesterol levels were 25% lower in IUGR compared with CTRL (p < 0.0001). Lanosterol and lathosterol to cholesterol ratios were similar in IUGR and CTRL. In relation to cholesterol mean, desmosterol, 24S-hydroxycholesterol, and 27-hydroxycholesterol levels were higher by 30.0, 39.1 and 60.7%, respectively, in IUGR compared to CTRL (p < 0.0001). Equally, 5α-cholestanol, campesterol, and β-sitosterol to cholesterol ratios were higher in IUGR than in CTRL (17.2%, p < 0.004; 33.5%, p < 0.002; 29.3%, p < 0.021).. Cholesterol deficiency in IUGR is the result of diminished fetal de novo synthesis rates rather than diminished maternal supply. However, increased oxysterol- and phytosterol to cholesterol ratios suggest a lower sterol elimination rate. This is likely caused by a restricted hepatobiliary function. Understanding the fetal cholesterol metabolism is important, not only for neonatal nutrition, but also for the development of strategies to reduce the known risk of future cardiovascular diseases in the IUGR fetus.

Topics: Adult; Cholesterol; Female; Fetal Blood; Fetal Growth Retardation; Gas Chromatography-Mass Spectrometry; Humans; Hydroxycholesterols; Infant, Newborn; Phytosterols; Placenta; Pregnancy; Sitosterols

Topics: Cholesterol; Chromatography, Gas; Dietary Supplements; Phytosterols; Serenoa; Sitosterols; Stigmasterol

Sewage pollution is a principal factor of decreasing water quality, although it has not been considered a real impact in Amazonia that is still considered a pristine environment around the world. Thus, this study aimed to assess the levels of sewage contamination in sediments from three streams crossing Manaus - a Brazilian city of 2,403,796 inhabitants in the heart of the Amazon rain forest. Cholesterol, cholestanol, brassicasterol, ergosterol, stigmasterol, β-sitosterol, campesterol, stigmastanol, coprostanol, and epicoprostanol levels were determined by liquid chromatography tandem mass spectrometry (LC-MS/MS). The fecal indicator, coprostanol, was found in high concentrations (509-12 830 ng g

Topics: Biomarkers; Brazil; Cholestadienols; Cholestanol; Cholestanols; Cholesterol; Chromatography, Liquid; Drug Contamination; Environmental Monitoring; Feces; Geologic Sediments; Phytosterols; Rivers; Sewage; Sitosterols; Sterols; Tandem Mass Spectrometry; Water Pollutants; Water Pollution; Water Quality

Phytosterol metabolism is unknown in the hypercholesterolemia of genetic origin. We investigated the metabolism of phytosterols in a cholesterol-free, phytosterol-containing standard diet in hypercholesterolemic mice knockouts for low density lipoprotein receptor (LDLR) and apolipoprotein E (apoE) mice compared to wild-type mice (controls). Phytosterols were measured in mice tissues by GCMS. ApoE-KO mice absorbed less phytosterols than LDLR-KO and the latter absorbed less phytosterols than control mice, because the intestinal campesterol content was low in both KO mice, and sitosterol was low in the intestine in apoE-KO mice as compared to LDLR-KO mice. Although the diet contained nine times more sitosterol than campesterol, the concentration of sitosterol was lower than that of campesterol in plasma in LDLR-KO, and in the liver in controls and in LDLR-KO, but only in apoE-KO. On the other hand, in the intestine sitosterol was higher than campesterol in controls, and in LDLR-KO but with a tendency only in apoE-KO. Because of the high dietary supply of sitosterol, sitosterol was better taken up by the intestine than campesterol, but the amount of sitosterol was lower than that of campesterol in the liver, while in the whole body the amounts of these phytosterols do not differ from each other. Therefore, via intestinal lymph less sitosterol than campesterol was transferred to the body. However, as compared to controls, in apoE-KO mice, but not in LDLR-KO mice, the increase in campesterol and sitosterol in plasma and in the whole body indicating that apoE-KO mice have a marked defect in the elimination of both phytosterols from the body.

Topics: Animal Feed; Animals; Cholesterol; Liver; Mice; Mice, Knockout, ApoE; Phytosterols; Receptors, LDL; Sitosterols; Species Specificity

The important role of histone deacetylases (HDACs) in the development of cancer has been demonstrated by various studies. Thus targeting HDACs with inhibitors is a major focus in anticancer drug research. Although few synthetic HDAC inhibitors (HDIs) have been approved for cancer treatment, they have significant undesirable side effects. Therefore emphases have been placed on natural HDIs as substitutes for the synthetic ones. In a bid to identify more HDIs, this study evaluated the binding tendency of compounds derived from Morinda lucida Benth. towards selected HDACs for the discovery of potent HDIs as potential candidates for anticancer therapeutics, based on the report of anticancer potentials of Morinda lucida-derived extracts and compounds. Givinostat and 49 Morinda-lucida derived compounds were docked against selected HDAC isoforms using AutodockVina, while binding interactions were viewed with Discovery Studio Visualizer, BIOVIA, 2016. Druglikeness and Absorption-Distribution-Metabolism-Excretion (ADME) parameters of the top 7 compounds were evaluated using the Swiss online ADME web tool. The results revealed that out of the 49 compounds, 3 phytosterols (campesterol, cycloartenol, and stigmasterol) and 2 triterpenes (oleanolic acid and ursolic acid) exhibited high HDAC inhibitory activity compared to givinostat. These 5 compounds also fulfill oral drugability of Lipinski rule of five. Morinda lucida-derived phytosterols and triterpenes show high binding tendency towards the selected HDACs and exhibited good drugability characteristics and are therefore good candidates for further studies in the search for therapies against abnormalities linked with over-activity of HDACs.

Topics: Cholesterol; Histone Deacetylase Inhibitors; Histone Deacetylases; Humans; Molecular Docking Simulation; Morinda; Oleanolic Acid; Phytosterols; Plant Extracts; Plant Leaves; Protein Isoforms; Stigmasterol; Triterpenes; Ursolic Acid

Topics: Cholestanol; Cholesterol; Gas Chromatography-Mass Spectrometry; Humans; Hypercholesterolemia; Intestinal Diseases; Limit of Detection; Lipid Metabolism, Inborn Errors; Phytosterols; Reference Standards; Sitosterols; Xanthomatosis, Cerebrotendinous

Serum concentrations of lathosterol, the plant sterols campesterol and sitosterol and the cholesterol metabolite 5α-cholestanol are widely used as surrogate markers of cholesterol synthesis and absorption, respectively. Increasing numbers of laboratories utilize a broad spectrum of well-established and recently developed methods for the determination of cholesterol and non-cholesterol sterols (NCS). In order to evaluate the quality of these measurements and to identify possible sources of analytical errors our group initiated the first international survey for cholesterol and NCS. The cholesterol and NCS survey was structured as a two-part survey which took place in the years 2013 and 2014. The first survey part was designed as descriptive, providing information about the variation of reported results from different laboratories. A set of two lyophilized pooled sera (A and B) was sent to twenty laboratories specialized in chromatographic lipid analysis. The different sterols were quantified either by gas chromatography-flame ionization detection, gas chromatography- or liquid chromatography-mass selective detection. The participants were requested to determine cholesterol and NCS concentrations in the provided samples as part of their normal laboratory routine. The second part was designed as interventional survey. Twenty-two laboratories agreed to participate and received again two different lyophilized pooled sera (C and D). In contrast to the first international survey, each participant received standard stock solutions with defined concentrations of cholesterol and NCS. The participants were requested to use diluted calibration solutions from the provided standard stock solutions for quantification of cholesterol and NCS. In both surveys, each laboratory used its own internal standard (5α-cholestane, epicoprostanol or deuterium labelled sterols). Main outcome of the survey was, that unacceptably high interlaboratory variations for cholesterol and NCS concentrations are reported, even when the individual laboratories used the same calibration material. We discuss different sources of errors and recommend all laboratories analysing cholesterol and NCS to participate in regular quality control programs.

Topics: Cholestanol; Cholesterol; Chromatography, Gas; Chromatography, Liquid; Humans; Phytosterols; Sitosterols; Surveys and Questionnaires

Milk fat adulteration is a common issue in Central Asia. To assess the current situation in the commercial milk market, 17 milk samples were checked for fatty acid (FA) and sterol profiles to detect potential adulteration using multivariate analysis. Analysis of FA and sterols was performed using gas chromatography with flame ionization detection and gas chromatography with mass-spectrometric detection, respectively. Cluster analysis of FA profiles revealed 3 types of milk samples: (1) samples containing a higher proportion of short-chain FA, (2) samples containing a higher proportion of long-chain FA, and (3) samples with significant amounts of C18 FA. Analysis of sterols showed that samples included (1) milk fat containing 100% cholesterol, sometimes with traces of phytosterols, (2) milk fat with high proportions of β-sitosterol and campesterol, and (3) milk fat containing high proportions of brassicasterol. We found significant relationships between FA profiles and sterol profiles. The profiles were compared with vegetable oil patterns reported in the literature. More than 50% of the samples appeared to be counterfeited. We conclude that identification of adulteration in milk can be based solely on determination of sterol patterns.

Topics: Animals; Cholestadienols; Cholesterol; Fatty Acids; Food Contamination; Gas Chromatography-Mass Spectrometry; Milk; Phytosterols; Plant Oils; Sitosterols; Sterols

Plant sterol (PS) oxidation products (POP) derived from sitosterol and campesterol were measured in 15 foods cooked with liquid margarine without (control) and with added 7.5% PS. POP were analyzed using a GC-MS method. PS liquid vs. control margarine resulted in a higher median POP content per food portion (1.35mg, range 0.08-13.20mg versus 0.23mg, 0.06-0.90mg), a lower PS oxidation rate (0.63 vs. 1.29%) and lower oxidation susceptibility of sitosterol vs. campesterol. POP formation was highest in shallow-fried potatoes with PS liquid margarine (64.44mg per portion food plus residual fat). Mean relative abundances of epoxy-, 7-keto-, 7-hydroxy- and triol-PS derived from sitosterol and campesterol were 40.0, 34.4, 21.5 and 4.0% with control vs. 44.1, 23.8, 29.6 and 2.4% with PS liquid margarine. In conclusion, PS liquid margarine increased POP content in foods with a POP profile characterized by a higher ratio of epoxy- to 7-keto-derivatives.

Topics: Cholesterol; Cooking; Esters; Margarine; Oxidation-Reduction; Phytosterols; Sitosterols

The eryptotic and hemolytic effects of a phytosterol (PS) mixture (β-sitosterol, campesterol, stigmasterol) or β-cryptoxanthin (β-Cx) at physiological serum concentration and their effect against oxidative stress induced by tert-butylhydroperoxide (tBOOH) (75 and 300 μM) were evaluated. β-Cryptoxanthin produced an increase in eryptotic cells, cell volume, hemolysis, and glutathione depletion (GSH) without ROS overproduction and intracellular Ca

Topics: Beta-Cryptoxanthin; Cells, Cultured; Cholesterol; Eryptosis; Erythrocytes; Glutathione; Hemolysis; Humans; Oxidative Stress; Phytosterols; Sitosterols; Stigmasterol; tert-Butylhydroperoxide

The aim of the study was to investigate how the dietary sterol composition, including cholesterol, phytosterol:cholesterol ratio and phytosterols, affect the absorption, biliary excretion, retention, tissue storage and distribution of cholesterol and individual phytosterols in Atlantic salmon (Salmo salar L.). A feeding trial was conducted at two different temperatures (6 and 12°C), using nine different diets with varying contents of phytosterols, cholesterol and phytosterol:cholesterol ratio. Cholesterol retention values were clearly dependent on dietary cholesterol, and showed that fish fed cholesterol levels <1000 mg/kg feed produced considerable quantities of cholesterol de novo. Despite this production, cholesterol content increased with increasing dietary cholesterol in liver, plasma, bile, muscle, adipose tissue and whole fish at 12°C, and in plasma, bile and whole fish at 6°C. The tissue sterol composition generally depended on the dietary cholesterol content and on the dietary phytosterol:cholesterol ratio, but not on the dietary phytosterol content in itself. Campesterol and brassicasterol appeared to be the phytosterols with the highest intestinal absorption in Atlantic salmon. There was a high biliary excretion of campesterol, but not of brassicasterol, which accumulated in tissues and particularly in adipose tissue, with 2-fold-higher retention at 12°C compared with 6°C. Campesterol had the second highest retention of the phytosterols in the fish, but with no difference between the two temperatures. Other phytosterols had very low retention. Although brassicasterol retention decreased with increasing dietary phytosterols, campesterol retention decreased with increasing dietary cholesterol, indicating differences in the uptake mechanisms for these two sterols.

Topics: Animals; Cholestadienols; Cholesterol; Diet; Intestinal Absorption; Liver; Phytosterols; Salmo salar; Sterols

Apolipoprotein E knockout (apoE-KO) mice present synaptic loss, cognitive dysfunction, and high plasma lipid levels that may affect brain function simulating Alzheimer disease. Plasma and brain sterols were measured in apoE-KO and in wild type control mice on a cholesterol-free, phytosterol-containing diet by gas chromatography coupled to a mass spectrometer. Plasma cholesterol and phytosterols (campesterol and sitosterol) were higher in apoE-KO compared to control mice. Cholesterol precursors (desmosterol and lathosterol) were not detected in plasma of control mice but were present in apoE-KO mice. In the brain amounts of cholesterol, desmosterol, campesterol and 24-hydroxycholesterol were significantly lower in apoE-KO than in controls. There is a tendency in apoE-KO for lower values of 7α-hydroxycholesterol and 7β-hydroxycholesterol. Cholesterol content, synthesis rates (desmosterol) and export of 24-hydroxycholesterol are reduced in the brain of the severe hypercholesterolemic apoE-KO mice.

Topics: Alzheimer Disease; Animals; Apolipoproteins E; Biological Transport; Brain; Cholesterol; Hydroxycholesterols; Mice; Mice, Knockout; Phytosterols

The appearance of drug-resistant (DR) bacteria in the community is a crucial development, and is associated with increased morbidity, mortality, healthcare costs, and antibiotic use. Natural oil nanoemulsions (NEs) have potential for antimicrobial applications. In the present study, we determined the antimicrobial activity of an NE against DR bacterial pathogens in vitro. The NE comprised Cleome viscosa essential oil, Tween 80 nonionic surfactant, and water. We found that an NE with a droplet size of 7 nm and an oil:surfactant (v/v) ratio of 1:3 was effective against methicillin-resistant Staphylococcus aureus (MRSA), DR Streptococcus pyogenes, and DR extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Fourier-transform infrared (FTIR) spectroscopy revealed that NE treatment modified the functional groups of lipids, proteins, and nucleic acids in DR bacterial cells. Scanning electron microscopy (SEM) showed damage to the cell membranes and walls of NE-treated DR bacteria. These alterations were caused by bioactive compounds with wide-spectrum enzyme-inhibiting activity in the NE, such as β-sitosterol, demecolcine, campesterol, and heneicosyl formate. The results suggest that the nanoemulsion is effective against DR bacteria, and acts by inhibiting the drug efflux mechanism of DR strains.

Topics: Anti-Bacterial Agents; Anti-Infective Agents; Cholesterol; Cleome; Demecolcine; Drug Resistance, Bacterial; Emulsions; Escherichia coli; Klebsiella pneumoniae; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Nanostructures; Oils, Volatile; Particle Size; Phytosterols; Plant Extracts; Polysorbates; Pseudomonas aeruginosa; Sitosterols; Sonication; Streptococcus pyogenes; Surface-Active Agents

There has been an increasing interest during recent years in the role of the gut microbiome on health and disease. Therefore, metabolites in human feces related to microbial activity are attractive surrogate marker to track changes of microbiota induced by diet or disease. Such markers include 5α/β-stanols as microbiome-derived metabolites of sterols. Currently, reliable, robust, and fast methods to quantify fecal sterols and their related metabolites are missing. We developed a liquid chromatography-high-resolution mass spectrometry (LC-MS/HRMS) method for the quantification of sterols and their 5α/β-stanols in human fecal samples. Fecal sterols were extracted and derivatized to N, N-dimethylglycine esters. The method includes cholesterol, coprostanol, cholestanol and sitosterol, 5α/β-sitostanol, campesterol and 5α/β-campestanol. Application of a biphenyl column permits separation of isomeric 5α- and 5β-stanols. Sterols are detected in parallel reaction monitoring (PRM) mode and stanols in full scan mode. HRMS allows differentiation of isobaric β-stanols and the [M + 2] isotope peak of the coeluting sterol. Performance characteristics meet the criteria recommended by Food and Drug Administration (FDA) and European Medicines Agency (EMA) guidelines. Analysis of fecal samples from healthy volunteers revealed high interindividual variability of sterol and stanol fractions. Interestingly, cholesterol and sitosterol showed similar fractions of mainly 5β-stanols. In contrast, campesterol is substantially converted to 5α-campestanol and might be a poorer substrate for bacterial metabolism. Robust and fast quantification of fecal sterols and their related stanols by LC-MS/HRMS offers great potential to find novel microbiome-related biomarker in large-scale studies.

Topics: Cholesterol; Chromatography, Liquid; Feces; Gastrointestinal Microbiome; Humans; Limit of Detection; Phytosterols; Sitosterols; Sterols; Tandem Mass Spectrometry

Impaired glucose metabolism during pregnancy may associate with changes in fetal cholesterol metabolism. We investigated if gestational diabetes mellitus (GDM) affects newborn cholesterol metabolism as determined by cord blood squalene and non-cholesterol sterols. Furthermore, we examined potential correlations between cord blood and maternal serum non-cholesterol sterols.. Pregnant women at risk for GDM (BMI>30 kg/m. The ratios of squalene and non-cholesterol sterols to cholesterol (100 × μmol/mmol of cholesterol) in cord blood did not differ between the infants born to mothers with GDM (n = 15) or mothers with normal glucose tolerance (n = 13). The ratios of sitosterol and campesterol to cholesterol in the cord blood correlated with the corresponding maternal serum ratios (r = 0.70, p < 0.0001) in both groups.. In obese women under good glycaemic control, GDM did not affect newborn cholesterol metabolism. Cord blood sitosterol and campesterol ratios to cholesterol correlated with the corresponding maternal serum ratios thus potentially reflecting maternal-fetal cholesterol transport.

Topics: Adult; Biomarkers; Blood Glucose; Case-Control Studies; Cholestanol; Cholesterol; Diabetes, Gestational; Female; Fetal Blood; Finland; Humans; Infant, Newborn; Maternal-Fetal Exchange; Obesity; Phytosterols; Pregnancy; Sitosterols; Squalene

To engineer Yarrowia lipolytica for improving the heterologous production of campesterol (a key precursor to manufacture pharmaceutical steroids).. By screening 7-dehydrocholesterol reductase (DHCR7) from diverse species, DHCR7 from Danio rerio was the best candidate for campesterol synthesis. Overexpression of ACL (ATP: citrate lyase) or POX2 (peroxisome acyl-CoA oxidase 2) were key to improving campesterol production. The highest yield of campesterol was 942 mg/l was with the strain overexpressing POX2 in a 5 l bioreactor via high cell density fermentation process with a restricted supply of carbon sourc, sunflower seed oil.. A promising platform to synthesize downstream steroid drugs was established. Efficient approaches were provided to improve the production of desired molecules in Y. lipolytica with high oil utilization efficiency.

Topics: Animals; ATP Citrate (pro-S)-Lyase; Bioreactors; Biosynthetic Pathways; Cholesterol; Gene Expression; Metabolic Engineering; Oxidoreductases; Oxidoreductases Acting on CH-CH Group Donors; Phytosterols; Recombinant Proteins; Yarrowia; Zebrafish

Predictions of global increased temperature are for 1.8-4 °C by 2100. Increased temperature as an abiotic stress may exert a considerable influence on the levels of secondary metabolites in plants. These secondary metabolites may possibly exert biological activities beneficial in prevention or treatment of disorders linked to oxidative stress in human. Wheat secondary compounds in three Canadian and three Australian genotypes grown under controlled environments, in which the only changing parameter was temperature, were investigated. Kennedy and AC Navigator contained the highest amount of total phenolic acids among Australian and Canadian wheat genotypes, respectively. The total phenolic acids and total flavonoid contents of wheat genotypes increased following the increase of the growing temperature. In all the wheat genotypes, regardless of their growing temperatures, linoleic acid (C18:2n6) was measured as the main fatty acid. Significant increases in palmitic acid (C16:0) and oleic acid (C18:1n9) and significant decreases in linoleic acid (C18:2n6) and linolenic acid (C18:3n3) were observed at increased of growing temperature for all wheat genotypes. Growing temperature decreased campesterol content of wheat genotypes. Genotype and growing temperature significantly shifted the production of wheat secondary metabolites. This information might be used as a guide for breeding wheat varieties with higher antioxidant properties.

Topics: alpha-Linolenic Acid; Australia; Canada; Cholesterol; Environment, Controlled; Flavonoids; Genotype; Hot Temperature; Hydroxybenzoates; Oxidative Stress; Phytosterols; Secondary Metabolism; Triticum

This study aimed to investigate the effect of metal ions on the degradation of phytosterols in oils. The oil was heated at 180°C for 1h with/without addition of Fe

Topics: Antioxidants; Cholestadienols; Cholesterol; Food Analysis; Food Handling; Gas Chromatography-Mass Spectrometry; Hot Temperature; Nutritive Value; Oils; Phytosterols; Sitosterols; Steroids; Stigmasterol

The in vivo antifungal activity of crude extracts of Dipsacus asper roots was evaluated against the phytopathogenic fungi Botrytis cinerea, Colletotrichum coccodes, Blumeria graminis f. sp. hordei, Magnaporthe grisea, Phytophthora infestans, Puccinia recondita and Rhizoctonia solani using a whole-plant assay method. Ethyl acetate and acetone extracts, at 1000μg/mL, suppressed the development of tomato gray mold (TGM) and tomato late blight (TLB) by 90%. Through bioassay-guided isolation, five antifungal substances were isolated from the D. asper roots and identified as β-sitosterol (1), campesterol (2), stigmasterol (3), cauloside A (4) and a novel dipsacus saponin, named colchiside (3-O-β-d-xylopyranosyl-23-O-β-d-glucopyranosyl-28-O-β-d-(6-O-acetyl)-glucopyranosyl hederagenin) (5). Of those, cauloside A (4) displayed the greatest antifungal efficacy against rice blast, TGM and TLB. Colchiside (5) moderately suppressed the development of TLB, but exhibited little effect against the other diseases. The synergistic effects of the isolated compounds against TLB were also assessed. Synergistic and additive interactions were observed between several of the sterol compounds. This study indicated that the crude extracts of, and bioactive substances from, the roots of D. asper suppress TGM and TLB. In addition, cauloside A (4) and colchiside (5) could be used as antifungal lead compounds.

Topics: Antifungal Agents; Cholesterol; Dipsacaceae; Oleanolic Acid; Phytosterols; Plant Roots; Saponins; Sitosterols; Sterols

Parenteral plant sterols (PSs) are considered hepatotoxic; however, liver PSs and their associations with liver injury in patients with intestinal failure (IF) have not been reported.. We analyzed liver and serum PS (avenasterol, campesterol, sitosterol, and stigmasterol) concentrations and ratios to cholesterol and their associations with biochemical and histologic liver damage in children with IF during (n = 7) parenteral nutrition (PN) and after weaning off it (n = 9), including vegetable oil-based lipid emulsions.. Liver avenasterol, sitosterol, and total PS concentrations and cholesterol ratios were 2.4-fold to 5.6-fold higher in PN-dependent patients ( P < .05). Parenteral PS delivery reflected liver avenasterol and sitosterol ratios to cholesterol ( r = 0.83-0.89, P = .02-.04), while serum and liver total PS levels were positively interrelated ( r = 0.98, P < .01). Any liver histopathology was equally common while portal inflammation more frequent (57 vs 0%, P = .02) in PN-dependent patients. All liver PS fractions correlated positively with histologic portal inflammation ( r = 0.53-0.66, P < .05), and their total concentration was significantly ( P = .01) higher among patients with versus without portal inflammation. In PN-dependent patients, liver fibrosis and any histopathology correlated with liver campesterol and stigmasterol levels ( r = 0.79-0.87, P ≤ .03).. Among children with IF, parenteral PSs accumulate in the liver, reflect their increased serum levels, and relate with biochemical liver injury, portal inflammation, and liver fibrosis, thus supporting their role in promoting liver damage.

Topics: Alanine Transaminase; Aspartate Aminotransferases; Chemical and Drug Induced Liver Injury; Child; Child, Preschool; Cholesterol; Female; gamma-Glutamyltransferase; Humans; Infant; Inflammation; Intestinal Diseases; Liver; Male; Parenteral Nutrition; Phytosterols; Plant Oils; Portal Vein; Sitosterols; Stigmasterol; Triglycerides

Regulation of cholesterol (Chol) homeostasis is controlled by three main fluxes, i.e. intestinal absorption, de novo synthesis (ChS) and catabolism, predominantly as bile acid synthesis (BAS). High serum total Chol and LDL-Chol concentrations in particular are considered risk factors and markers for the development of atherosclerosis. Pharmaceutical treatments to lower serum Chol have focused on reducing absorption or ChS and increasing BAS. Monitoring of these three parameters is complex involving isotope techniques, cholesterol balance experiments and advanced mass spectrometry based analysis methods. Surrogate markers were explored that require only one single fasting blood sample collection. These markers were validated in specific, mostly physiological conditions and during statin treatment to inhibit ChS. They were also applied under cholesterol absorption restriction, but were not validated in this condition. We retrospectively evaluated the use of serum campesterol (Camp), sitosterol (Sit) and cholestanol (Cholol) as markers for cholesterol absorption, lathosterol (Lath) as marker for ChS and 7α-hydroxycholesterol (7α-OH-Ch) and 27-hydroxycholesterol (27-OH-Ch) as markers for BAS under conditions of Chol absorption restriction. Additionally, their values were corrected for Chol concentration (R_sterol or oxysterols).. Thirty-seven healthy male omnivore subjects were studied under treatments with placebo (PLAC), ezetimibe (EZE) to inhibit cholesterol absorption, simvastatin (SIMVA) to reduce cholesterol synthesis and a combination of both (EZE+SIMVA). Results were compared to those obtained in 18 pure vegetarian subjects (vegans) whose dietary Chol intake is extremely low. Relative or fractional Chol absorption (FrChA) was measured with the continuous feeding stable isotope procedure, ChS and BAS with the cholesterol balance method. The daily Chol intake (DICh) was inventoried and the daily Chol absorption (DACh) calculated.. Monitoring cholesterol absorption, R_Camp, R_Sit and R_Cholol responded sensitively to changes in FrChA. R_Camp correlated well with FrChA in all omnivore treatment groups and in the vegan group. R_Camp confirmed reduced FrChA under EZE treatment and reduced DACh in the vegan subjects. R_Sit and R_Cholol did not accurately reflect FrChA or DACh in all situations. Monitoring endogenous cholesterol synthesis, R_Lath correlated with ChS in the vegan group, but in none of the omnivore treatment groups. R_Lath confirmed increased ChS under EZE treatment and was reduced under SIMVA treatment, while ChS was not. An increased ChS under EZE+SIMVA treatment could not be confirmed with R_Lath. R_Lath responded very insensitively to a change in ChS. Monitoring BAS, R_7α-OH-Ch but not R_27-OH-Ch correlated with BAS during PLAC, EZE and SIMVA treatments. In line with BAS, R_7α-OH-Ch did not differ in any of the omnivore treatment groups. R_7α-OH-Ch responded insensitively to a change in BAS.. Under Chol absorption restriction, serum R_Camp is a sensitive and valid marker to monitor FrChA in a population with a normal DICh. Also, major changes in DACh can be detected in vegans. Serum R_Lath does not reflect ChS measured with the cholesterol balance method during EZE treatment. This result initiates the question whether the measured ChS reflects pure de novo synthesis. Serum R_7α-OH-Ch appears to be a valid but insensitive marker for BAS.

Topics: Adult; Azetidines; Bile Acids and Salts; Biomarkers; Cholesterol; Diet, Vegan; Drug Therapy, Combination; Feces; Female; Humans; Hydroxycholesterols; Hypolipidemic Agents; Lipid Metabolism; Male; Middle Aged; Phytosterols; Reproducibility of Results; Retrospective Studies; Simvastatin; Up-Regulation

Little is known about whether the alteration of cholesterol metabolism reflects abdominal organ impairments due to heart failure. Therefore, we investigated the prognostic value of cholesterol metabolism by evaluating serum campesterol and lathosterol levels in patients with early-stage nonischemic dilated cardiomyopathy (NIDCM).. We enrolled 64 patients with NIDCM (median age 57.5 years, 31% female) with New York Heart Association functional class I/II. Serum campesterol and lathosterol levels were measured in all patients. The patients were then divided into four subsets based on the median non-cholesterol sterol levels (campesterol 3.6μg/mL, lathosterol 1.4μg/mL): reference (R-subset), high-campesterol/high-lathosterol; absorption-reduced (A-subset), low-campesterol/high-lathosterol; synthesis-reduced (S-subset), high-campesterol/low-lathosterol; double-reduced (D-subset), low-campesterol/low-lathosterol. Endpoint was a composite of cardiac events, including cardiac-related death, hospitalization for worsening heart failure, and lethal arrhythmia.. Median brain natriuretic peptide (BNP) level was 114pg/mL. Mean left ventricular ejection fraction was 31.4%. D-subset had the lowest total cholesterol level and cardiac index and the highest BNP level and pulmonary capillary wedge pressure. D-subset also had the highest cardiac event rate during the mean 3.8 years of follow-up (log-rank p=0.001). Multivariate regression analysis showed that D-subset was an independent determinant of cardiac events. The receiver operating characteristic curve analysis revealed that total cholesterol <153mg/dL was a best cut-off value for discrimination of the D-subset.. The combined reduction of campesterol and lathosterol that indicated intestinal cholesterol absorption and liver synthesis predicts future cardiac events in patients with mildly symptomatic NIDCM.

Topics: Adult; Aged; Arrhythmias, Cardiac; Biomarkers; Cardiomyopathy, Dilated; Cholesterol; Female; Heart Failure; Heart Rate; Hospitalization; Humans; Lipid Metabolism; Male; Middle Aged; Phytosterols; Prognosis; Ventricular Function, Left

Compounds with estrogenic potencies and their adverse effects in surface waters have received much attention. Both anthropogenic and natural compounds contribute to overall estrogenic activity in freshwaters. Recently, estrogenic potencies were also found to be associated with cyanobacteria and their blooms in surface waters. The present study developed and compared the solid phase extraction and LC-MS/MS analytical approaches for determination of phytoestrogens (8 flavonoids - biochanin A, coumestrol, daidzein, equol, formononetin, genistein, naringenin, apigenin - and 5 sterols - ergosterol, β-sitosterol, stigmasterol, campesterol, brassicasterol) and cholesterol in water. The method was used for analyses of samples collected in stagnant water bodies dominated by different cyanobacterial species. Concentrations of individual flavonoids ranged from below the limit of detection to 3.58 ng/L. Sterols were present in higher amounts up to 2.25 μg/L. Biological potencies of these phytoestrogens in vitro were characterized using the hERα-HeLa-9903 cell line. The relative estrogenic potencies (compared to model estrogen - 17β-estradiol) of flavonoids ranged from 2.25E-05 to 1.26E-03 with coumestrol being the most potent. None of the sterols elicited estrogenic response in the used bioassay. Estrogenic activity was detected in collected field water samples (maximum effect corresponding to 2.07 ng/L of 17β-estradiol equivalents, transcriptional assay). At maximum phytoestrogens accounted for only 1.56 pg/L of 17β-estradiol equivalents, contributing maximally 8.5% of the total estrogenicity of the water samples. Other compounds therefore, most likely of anthropogenic origin such as steroid estrogens, are probably the major drivers of total estrogenic effects in these surface waters.

Topics: Cholestadienols; Cholesterol; Cyanobacteria; Estradiol; Estrogens; Estrone; Fresh Water; Genistein; HeLa Cells; Humans; Isoflavones; Phytoestrogens; Phytosterols; Receptors, Estrogen; Sitosterols; Sterols; Tandem Mass Spectrometry; Water; Water Pollutants, Chemical

HPLC fingerprint analysis combined with chemometrics was developed to discriminate between the red and the white rice bran grown in Indonesia. The major component in rice bran is γ-oryzanol which consisted of 4 main compounds, namely cycloartenol ferulate, cyclobranol ferulate, campesterol ferulate and β-sitosterol ferulate. Separation of these four compounds along with other compounds was performed using C18 and methanol-acetonitrile with gradient elution system. By using these intensity variations, principal component and discriminant analysis were performed to discriminate the two samples. Discriminant analysis was successfully discriminated the red from the white rice bran with predictive ability of the model showed a satisfactory classification for the test samples. The results of this study indicated that the developed method was suitable as quality control method for rice bran in terms of identification and discrimination of the red and the white rice bran.

Topics: Cholesterol; Chromatography, High Pressure Liquid; Indonesia; Oryza; Phenylpropionates; Phytosterols; Sitosterols; Triterpenes

Phytosterols are bioactive compounds in plants with similar cholesterol-lowering properties as vegetarian diets. However, information on phytosterol intake and plasma plant sterols among vegetarians is sparse.. We examined dietary intake and plasma concentration of plant sterols and cholesterol across five dietary patterns in the Adventist Health Study-2 Calibration Sub-study (n = 861, 66% females, average age 61 years). To measure intake and plasma concentrations of these compounds, we used 24-h dietary recalls and gas-liquid chromatography-flame ionization detection, respectively. Mean (SD) total phytosterol and cholesterol intake were 363 (176) mg/day and 131 (111) mg/day; plasma β-sitosterol, campesterol, and cholesterol were 3.3 (1.7) μg/mL, 4.2 (2.3) μg/mL, and 1.9 (0.4) mg/mL, respectively. Total phytosterol intake was lowest among non-vegetarians (263 mg/day) and highest among vegans (428 mg/day) (p < 0.0001). Cholesterol intake was lowest among vegans (15.2 mg/day) and highest among non-vegetarians (124.6 mg/day) (p < 0.0001). Plasma plant sterols and cholesterol did not differ by diet. Cholesterol-adjusted plasma β-sitosterol and campesterol were significantly higher in Blacks than Whites, though no ethnic differences were observed in dietary intake of these plant sterols.. Dietary intake but not plasma concentration of plant sterols and cholesterol varies across distinct plant-based diets.

Topics: Aged; Cholesterol; Cross-Sectional Studies; Diet; Diet, Vegetarian; Female; Humans; Male; Middle Aged; North America; Nutrition Surveys; Phytosterols; Sitosterols

Pneumolysin is the one of the major virulence factor of the bacterium Streptococcus pneumoniae. In previous report, it is shown that β-sitosterol, a natural compound without antimicrobial activity, is a potent antagonist of pneumolysin. Here, two new pneumolysin natural compound inhibitors, with differential activity, were discovered via haemolysis assay. To explore the key factor of the conformation for the inhibition activity, the interactions between five natural compound inhibitors with differential activity and pneumolysin were reported using molecular modelling, the potential of mean force profiles. Interestingly, it is found that incorporation of the single bond (C22-C23-C24-C25) to replace the double bond (hydrocarbon sidechain) improved the anti-haemolytic activity. In view of the molecular modelling, binding of the five inhibitors to the conserved loop region (Val372, Leu460, and Tyr461) of the cholesterol binding sites led to stable complex systems, which was consistent with the result of β-sitosterol. Owing to the single bond (C22-C23-C24-C25), campesterol and brassicasterol could form strong interactions with Val372 and show higher anti-haemolytic activity, which indicated that the single bond (C22-C23-C24-C25) in inhibitors was required for the anti-haemolytic activity. Overall, the current molecular modelling work provides a starting point for the development of rational design and higher activity pneumolysin inhibitors.

Topics: Animals; Bacterial Proteins; Cholestadienols; Cholesterol; Hemolysis; Models, Molecular; Molecular Dynamics Simulation; Phytosterols; Sheep; Streptococcus pneumoniae; Streptolysins; Structure-Activity Relationship

Sterols are components present in the fat fraction of infant formulas (IFs). Their characterization is therefore of interest, though there are no official reference methods for their analysis in these matrices.. To validate a gas chromatographic method with flame ionization detection for the determination of animal (cholesterol and desmosterol) and plant sterols (brassicasterol, campesterol, stigmasterol, β-sitosterol and sitostanol) found in IFs. All correlation coefficients obtained for the calibration curves of sterols studied were >0.99. Limits of detection (<1 μg/100 mL) and quantification (<4 μg/100 mL) are suitable for sterols determination in IFs. The within-assay precision ranged from 1.6% to 8.8%, while the between-assay precision was <10% for most of sterols. Accuracy was satisfactory and was calculated by recovery assays (ranging 93-108%). The analytical parameters obtained showed the suitability of the proposed method for the determination of sterols in IFs.

Topics: Calibration; Cholestadienols; Cholesterol; Chromatography, Gas; Desmosterol; Flame Ionization; Infant Formula; Limit of Detection; Phytosterols; Reproducibility of Results; Sitosterols; Stigmasterol

The bioaccessibility (BA) of total and individual plant sterols (PS) of four commercial PS-enriched fermented milk beverages (designated as A to D) was evaluated using in vitro gastrointestinal digestion including the formation of mixed micelles. The fat content of the samples ranged from 1.1 to 2.2% (w/w), and PS enrichment was between 1.5 and 2.9% (w/w). β-Sitosterol, contained in all samples, was higher in samples A and B (around 80% of total PS). The campesterol content was C (22%) > A (7%) > B (5%). Sitostanol was the most abundant in sample D (85%). Stigmasterol was only present in sample C (33%). The greatest BA percentage for total PS corresponded to samples A and B (16-17%), followed by sample D (11%) and sample C (9%). The total BA was not related to the protein, lipid or PS content of the beverages, whereas samples with higher carbohydrates and fiber contents showed lower BA. The BA of the individual PS differed according to the sample considered, and was not related to the PS profile of the sample, thus indicating strong dependency upon the matrix (PS ingredient and other components). Although in vivo studies should be carried out to better assess the functionality of PS in functional foods such as enriched fermented milk beverages, our in vitro study is a useful preliminary contribution to evaluation of the efficacy of these products.

Topics: Biological Availability; Cholesterol; Cultured Milk Products; Dietary Carbohydrates; Dietary Fats; Dietary Fiber; Digestion; Food, Fortified; Functional Food; Gastrointestinal Tract; Micelles; Models, Biological; Phytosterols; Sitosterols; Stigmasterol

The by-products of seven different cereal grains were investigated as a source of extractable oil, rich in lipophilic bioactive compounds.. Oil yields (g kg(-1) DW) recovered from cereal by-products were as follows: 189 (rice bran) > 112 (wheat germ) > 74 (corn bran) > 58 (oat bran) > 41 (buckwheat bran) > 39 (spelt bran) > 33 (wheat bran) > 27 (rye bran). The main fatty acids identified in the studied oil samples were palmitic acid (11.39-17.23%), oleic acid (11.76-42.73%), linoleic acid (35.54-62.65%) and α-linolenic acid (1.05-9.46%). The range of total tocochromanols and phytosterols in the obtained oils was 0.369-3.763 and 1.19-35.24 g kg(-1) of oil, respectively. The oils recovered from buckwheat and corn bran, and wheat germ were dominated by tocopherols (99.9, 84.2 and 96.5%, respectively), whereas the oat, rice, rye, spelt, wheat bran oils were rich in tocotrienols (73.9, 79.6, 78.1, 90.6 and 73.8%, respectively). The campesterol and β-sitosterol constituted 10.1-32.5 and 30.4-63.7%, respectively, of total phytosterols contents identified in all of the studied samples.. The present study demonstrated that oils recovered from the cereal by-products are richer sources of bioactive compounds, compared with traditional oils. © 2015 Society of Chemical Industry.

Topics: Cholesterol; Edible Grain; Fatty Acids; Phytosterols; Plant Extracts; Plant Oils; Seeds; Sitosterols; Squalene; Tocopherols; Tocotrienols; Triticum

The dynamics of cholesterol homeostasis and the development of cardiovascular disease (CVD) are complex and multifactorial, to which adds individual variability in the proportion of cholesterol from exogenous versus endogenous sources. The aim of this study was to undertake the first characterization of cholesterol absorption and synthesis profiles in Portuguese hypercholesterolemic adults through the quantification of surrogate markers, and the analysis of the predictive value of age and sex on the cholesterol homeostasis biomarkers.. Serum samples for the measurement of lipid profiles and cholesterol homeostasis markers were obtained for 100 men and 112 women, aged 30-65, with TC ≥ 5.2 mmol/L (~200mg/dL) and/or LDL-C ≥ 2.6 mmol/L (~100mg/dL), none of whom were on any lipid-lowering therapy.. Overall, sex-specific significant differences were observed in the cholesterol homeostasis markers and lipid profiles; women had lower cholesterol synthesis marker concentrations (P<0.01 for lathosterol) and lipid parameters (except for HDL-C concentrations). Age-related significant differences were also found, including higher concentrations of cholesterol absorption markers in association with increasing age.. In our study, the predictors of higher levels of cholesterol absorption markers were higher age and female gender.

Topics: Adult; Age Factors; Aged; Biomarkers; Cholestanol; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Cross-Sectional Studies; Desmosterol; Diet; Female; Homeostasis; Humans; Hypercholesterolemia; Male; Middle Aged; Phytosterols; Portugal; Sex Factors; Sitosterols; Triglycerides

The interest in plant sterols enriched foods has recently enhanced due to their healthy properties. The influence of the unsaturation degree of different fatty acids methyl esters (FAME: stearate, oleate, linoletate and linolenate) on a mixture of three plant sterols (PS: campesterol, stigmasterol and β-sitosterol) was evaluated at 180 °C for up to 180 min. Sterols degraded slower in the presence of unsaturated FAME. Both PS and FAME degradation fit a first order kinetic model (R(2)>0.9). Maximum oxysterols concentrations were achieved at 20 min in neat PS and 120 min in lipid mixtures and this maximum amount decreased with increasing their unsaturation degree. In conclusion, the presence of FAME delayed PS degradation and postponed oxysterols formation. This protective effect was further promoted by increasing the unsaturation degree of FAME. This evidence could help industries to optimize the formulation of sterol-enriched products, so that they could maintain their healthy properties during cooking or processing.

Topics: alpha-Linolenic Acid; Cholesterol; Fatty Acids; Food Handling; Hot Temperature; Linoleic Acid; Oleic Acid; Phytosterols; Protective Agents; Sitosterols; Stearates; Stigmasterol

Certain lipid-lowering drugs increase bile lithogenicity. Here we investigated whether long-term administration of ezetimibe, a new class of hypocholesterolemic agents designed to inhibit intestinal cholesterol absorption by inhibiting Niemann-Pick C1-like 1, alters bile lithogenicity in patients with hepatobiliary diseases.. Eleven dyslipidemic patients with gallstones and/or fatty liver diseases were treated with ezetimibe (10 mg/day) for 12 months. Bile samples were collected by nasal endoscopy before and after 3 and 12 months of treatment. Serum and bile lipids and serum metabolic parameters were analyzed.. Serum levels of campesterol, total cholesterol, and low-density lipoprotein cholesterol were significantly decreased after 3 and 12 months of treatment. In contrast, serum lathosterol levels increased gradually. The lithogenic index of bile was unsaturated and unchanged in patients who were previously and concomitantly receiving ursodeoxycholic acid (UDCA). In patients who were not receiving UDCA, bile was initially supersaturated, but eventually was unsaturated. However, ezetimibe tended to elevate bile lithogenicity in cholecystectomy patients.. Long-term treatment with ezetimibe improves lipid metabolism without significantly altering the bile lithogenicity. Therefore, inhibiting intestinal cholesterol absorption in dyslipidemic patients with hepatobiliary diseases is a safe therapeutic strategy without worsening biliary physiology.

Topics: Anticholesteremic Agents; Bile; Cholesterol; Dyslipidemias; Ezetimibe; Fatty Liver; Female; Gallstones; Humans; Lipid Metabolism; Lipoproteins; Male; Middle Aged; Phytosterols; Ursodeoxycholic Acid

Campesterol is an important precursor for many sterol drugs, e.g. progesterone and hydrocortisone. In order to produce campesterol in Yarrowia lipolytica, C-22 desaturase encoding gene ERG5 was disrupted and the heterologous 7-dehydrocholesterol reductase (DHCR7) encoding gene was constitutively expressed. The codon-optimized DHCR7 from Rallus norvegicus, Oryza saliva and Xenapus laevis were explored and the strain with the gene DHCR7 from X. laevis achieved the highest titer of campesterol due to D409 in substrate binding sites. In presence of glucose as the carbon source, higher biomass conversion yield and product yield were achieved in shake flask compared to that using glycerol and sunflower seed oil. Nevertheless, better cell growth rate was observed in medium with sunflower seed oil as the sole carbon source. Through high cell density fed-batch fermentation under carbon source restriction strategy, a titer of 453±24.7 mg/L campesterol was achieved with sunflower seed oil as the carbon source, which is the highest reported microbial titer known. Our study has greatly enhanced campesterol accumulation in Y. lipolytica, providing new insight into producing complex and desired molecules in microbes.

Topics: Amino Acid Sequence; Animals; Bacterial Proteins; Binding Sites; Biomass; Bioreactors; Carbon; Cholesterol; Cytochrome P-450 Enzyme System; Fermentation; Genetic Engineering; Glucose; Glycerol; Industrial Microbiology; Lipids; Molecular Sequence Data; Oryza; Oxidoreductases Acting on CH-CH Group Donors; Phytosterols; Plant Oils; Rats; Sequence Homology, Amino Acid; Sunflower Oil; Xenopus laevis; Yarrowia

Phytosterols play an important role in plant growth and development, including cell division, cell elongation, embryogenesis, cellulose biosynthesis, and cell wall formation. Cotton fiber, which undergoes synchronous cell elongation and a large amount of cellulose synthesis, is an ideal model for the study of plant cell elongation and cell wall biogenesis. The role of phytosterols in fiber growth was investigated by treating the fibers with tridemorph, a sterol biosynthetic inhibitor. The inhibition of phytosterol biosynthesis resulted in an apparent suppression of fiber elongation in vitro or in planta. The determination of phytosterol quantity indicated that sitosterol and campesterol were the major phytosterols in cotton fibers; moreover, higher concentrations of these phytosterols were observed during the period of rapid elongation of fibers. Furthermore, the decrease and increase in campesterol:sitosterol ratio was associated with the increase and decease in speed of elongation, respectively, during the elongation stage. The increase in the ratio was associated with the transition from cell elongation to secondary cell wall synthesis. In addition, a number of phytosterol biosynthetic genes were down-regulated in the short fibers of ligon lintless-1 mutant, compared to its near-isogenic wild-type TM-1. These results demonstrated that phytosterols play a crucial role in cotton fiber development, and particularly in fiber elongation.

Topics: Cholesterol; Cotton Fiber; Mass Spectrometry; Phytosterols; Sitosterols

Dimunito/Dwarf1 (DWF1) is an oxidoreductase enzyme that is responsible for the conversion of C28- and C29-Δ(24(28))-olefinic sterols to 24-methyl- and 24-ethylcholesterols. Generally, the reaction proceeds in two steps via the Δ(24(25))intermediate. In this study, we characterized theArDWF1gene from an expression sequence tag library ofAjuga reptansvar.atropurpureahairy roots. The gene was functionally expressed in the yeast T21 strain. Thein vivoandin vitrostudy of the transformed yeast indicated that ArDWF1 catalyzes the conversion of 24-methylenecholesterol to campesterol. A labeling study followed by GC-MS analysis suggested that the reaction proceeded with retention of the C-25 hydrogen. The 25-H retention was established by the incubation of the enzyme with (23,23,25-(2)H3,28-(13)C)-24-methylenecholesterol, followed by(13)C NMR analysis of the resulting campesterol. Thus, it has been concluded that ArDWF1 directly reduces 24-methylenecholesterol to produce campesterol without passing through a Δ(24(25))intermediate. This is the first characterization of such a unique DWF1 enzyme. For comparison purposes,Oryza sativa DWF1(OsDWF1) was similarly expressed in yeast. Anin vivoassay of OsDWF1 supported the generally accepted two-step mechanism because the C-25 hydrogen of 24-methylenecholesterol was eliminated during its conversion to 24-methylcholesterol. As expected, the 24-methylcholesterol produced by OsDWF1 was a mixture of campesterol and dihydrobrassicasterol. Furthermore, the 24-methylcholesterol contained in theAjugahairy roots was determined to be solely campesterol through its analysis using chiral GC-MS. Therefore, ArDWF1 has another unique property in that only campesterol is formed by the direct reduction catalyzed by the enzyme.

Topics: Ajuga; Amino Acid Sequence; Cholesterol; Molecular Sequence Data; Oxidoreductases; Phylogeny; Phytosterols; Plant Proteins; Sequence Alignment

Low cholesterol is typically observed in the plasma of patients with cystic fibrosis (CF) contrasting with the subcellular accumulation of cholesterol demonstrated in CF cells and in mice models. However, the homeostasis of cholesterol has not been well investigated in patients with CF.. We studied the plasma of 26 patients with CF and 33 unaffected controls campesterol and β-sitosterol as markers of intestinal absorption and lathosterol as a marker of de novo cholesterol biosynthesis by gas chromatography (GC-FID and GC-MS).. Plasma campesterol and β-sitosterol results were significantly (p=0.01) lower while plasma lathosterol was significantly higher (p=0.001) in patients with CF as compared to control subjects. Plasma cholesterol results were significantly lower (p=0.01) in CF patients.. Our data suggest that the impaired intestinal absorption of exogenous sterols in patients with CF stimulates the endogenous synthesis of cholesterol, but the levels of total cholesterol in plasma remain lower. This may be due to the CFTR dysfunction that reduces cholesterol blood excretion causing the accumulation of cholesterol in liver cells and in other tissues contributing to trigger CF chronic inflammation.

Topics: Adolescent; Adult; Biomarkers; Child; Child, Preschool; Cholesterol; Chromatography, Gas; Cystic Fibrosis; Female; Humans; Infant; Intestinal Absorption; Male; Middle Aged; Phytosterols; Sterols; Young Adult

Patients with cardiac sarcoidosis (CS) suffer from myocardial inflammation, but atherosclerosis is not infrequent in these patients. However, the classical atherosclerotic risk factors, such as perturbed serum lipids and whole-body cholesterol metabolism, remain unravelled in CS.. We assessed serum non-cholesterol sterols, biomarkers of whole-body cholesterol synthesis and cholesterol absorption efficiency, with gas-liquid chromatography in 39 patients with histologically verified CS and in an age-adjusted random population sample (n = 124).. CS was inactive or responding to treatment in all patients. Concentrations of serum, LDL, and HDL cholesterol and serum triglycerides were similar in CS patients and in control subjects. Cholesterol absorption markers were higher in CS patients than in controls (eg serum campesterol to cholesterol ratio in CS 246 ± 18 vs in controls 190 ± 8 10(2) x μmol/mmol of cholesterol, p = 0.001). Cholesterol synthesis markers were lower in CS patients than in controls (eg serum lathosterol to cholesterol ratio in CS 102 ± 8 vs in controls 195 ± 5 10(2) x μmol/mmol of cholesterol, p = 0.000). In CS patients, cholesterol absorption markers significantly correlated with plasma prohormone brain natriuretic peptide (proBNP), a marker of hemodynamic load.. High cholesterol absorption efficiency, which is suggested to be atherogenic, characterized the metabolic profile of cholesterol in CS patients. The association between cholesterol absorption efficiency and plasma proBNP concentration, which suggests a link between inflammation, cholesterol homeostasis, and hemodynamic load, warrants further studies in order to confirm this finding and to reveal the underlying mechanisms.

Topics: Adult; Aged; Atherosclerosis; Body Mass Index; Cardiomyopathies; Case-Control Studies; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Diet; Down-Regulation; Female; Finland; Heart Diseases; Hemodynamics; Homeostasis; Humans; Inflammation; Lipoproteins; Male; Middle Aged; Phytosterols; Risk Factors; Sarcoidosis; Sitosterols

Topics: Cholestadienols; Cholesterol; Chromatography, High Pressure Liquid; Edible Grain; Factor Analysis, Statistical; Fruit and Vegetable Juices; Humans; Limit of Detection; Liquid Phase Microextraction; Phytosterols; Pisum sativum; Poaceae; Reproducibility of Results; Sitosterols; Stigmasterol; Tandem Mass Spectrometry

Topics: Animals; Cholesterol; Chromatography, High Pressure Liquid; Phytosterols; Rats; Reproducibility of Results; Sitosterols; Stigmasterol; Tandem Mass Spectrometry; Zea mays

A mixture of phytosterols/-stanols, consisting of 75% β-sitosterol, 12% sitostanol, 10% campesterol, 2% campestanol, and 1% others, was esterified with linoleic acid. The resulting mixture of phytosteryl/-stanyl linoleates was subjected to thermal oxidation at 180 °C for 40 min. A silica solid-phase extraction was applied to separate a fraction containing the nonoxidized linoleates and nonpolar degradation products (heptanoates, octanoates) from polar oxidation products (oxo- and hydroxyalkanoates). In total, 15 sitosteryl, sitostanyl, and campesteryl esters, resulting from oxidation of the acyl chain, could be identified by GC-FID/MS. Synthetic routes were described for authentic reference compounds of phytosteryl/-stanyl 7-hydroxyheptanoates, 8-hydroxyoctanoates, 7-oxoheptanoates, 8-oxooctanoates, and 9-oxononanoates, which were characterized by GC-MS and two-dimensional NMR spectroscopy. The study provides data on the formation and identities of previously unreported classes of acyl chain oxidation products upon thermal treatment of phytosteryl/-stanyl fatty acid esters.

Topics: Cholesterol; Esters; Hot Temperature; Linoleic Acids; Molecular Structure; Oxidation-Reduction; Phytosterols; Sitosterols

γ-Oryzanol, a mixture of ferulic acid esters of triterpene alcohols and sterols, is a nutritionally important group of rice secondary metabolites. A library of 27 γ-oryzanol was assembled from existing data and used to assist identification and quantification of γ-oryzanol isolated from 16 Korean rice varieties (11 white and 5 pigmented). γ-Oryzanol was analyzed with liquid chromatography with diode array detection and electrospray ionization mass spectrometry. Nineteen different γ-oryzanol were observed and identified as stigmasterol, campesterol and sitosterol or common and hydroxylated triterpene alcohols. In the 16 varieties, the total γ-oryzanol content averaged 43.8 mg/100 g (range, 26.7-61.6 mg/100 g), which Josaengheugchal exhibited the highest level (61.6 mg/100 g). The Korean rice varieties were classified based on qualitative and quantitative γ-oryzanol data by multivariate statistical analysis. Clusters of specialty rice varieties exhibited higher γ-oryzanol levels than those of common rice varieties.

Topics: Cholesterol; Chromatography, Liquid; Coumaric Acids; Humans; Korea; Oryza; Phenylpropionates; Phytosterols; Seeds; Species Specificity; Spectrometry, Mass, Electrospray Ionization; Triterpenes

The aim of the study was to assess the potential applicability of natural antioxidants in the stabilisation of phytosterols. A mixture of β-sitosterol and campesterol was incorporated into triacylglycerols (TAGs). The following antioxidants were added to the prepared matrix: green tea extract, rosemary extract, a mix of tocopherols from rapeseed oil, a mix of synthetic tocopherols, phenolic compounds extracted from rapeseed meal, sinapic acid and butylated hydroxytoluene (BHT). Samples were heated at a temperature of 180 °C for 4 h. After the completion of heating, the losses of phytosterols were analysed, as well as the contents of β-sitosterol and campesterol oxidation products. The total content of phytosterol oxidation products in samples ranged from 96.69 to 268.35 μg/g of oil. The effectiveness of antioxidants decreased in the following order: phenolic compounds from rapeseed meal>rosemary extract>mix of tocopherols from rapeseed oil>mix of synthetic tocopherols>green tea extract>sinapic acid>BHT.

Topics: Antioxidants; Cholesterol; Oxidation-Reduction; Phenols; Phytosterols; Tocopherols

An automated method for analyzing free non-cholesterol sterols in human serum using online solid phase extraction-liquid chromatography-mass spectrometry is proposed herein. The method allows the determination of three phytosterols (sitosterol, stigmasterol and campesterol) and two cholesterol precursors (desmosterol and lanosterol). The analysis of sterols in human serum is critical in the study of cholesterol-related disorders, such as inherited familial hypercholesterolemias. Special effort was made to isolate the analytes from the serum lipoproteins, their natural conveyance through the bloodstream. The sample treatment consisted of a Bligh-Dyer extraction followed by dilution of the extract. This treatment allowed the sample to be injected into the online system and ensured the correct detection of the analytes, while avoiding the matrix effects commonly related to serum samples. The analytical performance showed linear ranges that covered two orders of magnitude, with correlation coefficients above 0.99. Limits of detection and quantification ranged from 0.2 ng/mL to 13 ng/mL and from 1.0 ng/mL to 43 ng/mL, respectively. Recovery when spiking serum with a half or a tenth of the average concentration reported in human serum ranged from 99% to 111% and from 102% to 120%, respectively. Intra-day precision and inter-day precision were below 20%.

Topics: Cholesterol; Chromatography, Liquid; Desmosterol; Humans; Lanosterol; Limit of Detection; Mass Spectrometry; Phytosterols; Sitosterols; Solid Phase Extraction; Stigmasterol

The high diversity of the plant lipid mixture raises the question of their respective involvement in the definition of membrane organization. This is particularly the case for plant plasma membrane, which is enriched in specific lipids, such as free and conjugated forms of phytosterols and typical phytosphingolipids, such as glycosylinositolphosphoceramides. This question was here addressed extensively by characterizing the order level of membrane from vesicles prepared using various plant lipid mixtures and labeled with an environment-sensitive probe. Fluorescence spectroscopy experiments showed that among major phytosterols, campesterol exhibits a stronger ability than β-sitosterol and stigmasterol to order model membranes. Multispectral confocal microscopy, allowing spatial analysis of membrane organization, demonstrated accordingly the strong ability of campesterol to promote ordered domain formation and to organize their spatial distribution at the membrane surface. Conjugated sterol forms, alone and in synergy with free sterols, exhibit a striking ability to order membrane. Plant sphingolipids, particularly glycosylinositolphosphoceramides, enhanced the sterol-induced ordering effect, emphasizing the formation and increasing the size of sterol-dependent ordered domains. Altogether, our results support a differential involvement of free and conjugated phytosterols in the formation of ordered domains and suggest that the diversity of plant lipids, allowing various local combinations of lipid species, could be a major contributor to membrane organization in particular through the formation of sphingolipid-sterol interacting domains.

Topics: 1,2-Dipalmitoylphosphatidylcholine; Cell Line; Cell Membrane; Cholesterol; Imaging, Three-Dimensional; Lipids; Membrane Lipids; Microscopy, Confocal; Models, Molecular; Phosphatidylcholines; Phytosterols; Plants; Spectrometry, Fluorescence; Sphingolipids

The intact blood-brain barrier in mammalians prevents exchange of cholesterol loaden particles between periphery and brain and thus nearly all cholesterol in this organ originates from de novo synthesis. Dietary cholesterol homologues from plants, campesterol and sitosterol, are known to get enriched to some extent in the mammalian brain. We recently showed that Pdgfb(ret)(/)(ret) mice, with a pericyte deficiency and a leaking blood-brain barrier phenotype, have significantly higher levels of plant sterols in the brain compared to their heterozygous Pdgfb(ret)(/)(+) controls keeping the integrity of the blood-brain barrier (BBB). In order to further study the protective functionality of the BBB we synthesized a mixture of [(2)H6]campesterol/sitosterol and fed it for 10-40days to genetically different types of animals. There was a significant enrichment of both deuterium stable isotope labeled plant sterols in the brain of both strains of mice, however, with a lower enrichment in the controls. As expected, the percentage and absolute enrichment was higher for [(2)H6]campesterol than for the more lipophilic [(2)H6]sitosterol. The results confirm that a leaking BBB causes increased flux of plant sterols into the brain. The significant flux of the labeled plant sterols into the brain of the control mice illustrates that the presence of an alkyl group in the 24-position of the steroid side chain markedly increases the ability of cholesterol to pass an intact BBB. We discuss the possibility that there is a specific transport mechanism involved in the flux of alkylated cholesterol species across the BBB.

Topics: Animals; Biological Transport; Blood-Brain Barrier; Cholesterol; Deuterium; Mass Spectrometry; Mice, Transgenic; Phytosterols; Proto-Oncogene Proteins c-sis; Sitosterols

We describe the validation of a method for the analysis of oxysterols, i.e. oxycholesterols and oxyphytosterols, in human serum using gas chromatography-mass spectrometry selected ion monitoring (GC-MS-SIM). Concentrations of 7α- and 7β-hydroxy-, and 7oxo-cholesterol, -campesterol, and -sitosterol as well as 4β-hydroxycholesterol and side-chain oxygenated 24S-, 25-, and 27-hydroxycholesterol were determined by isotope dilution methodology. After saponification at room temperature the oxysterols were extracted, separated from their substrates, cholesterol, campesterol, and sitosterol, by solid phase extraction, and subsequently derivatised to their corresponding trimethylsilyl-ethers prior to GC-MS-SIM. In order to prevent artificial autoxidation butylated hydroxytoluene and ethylenediaminetetraacetic acid were added. The validation of the method was performed according to the International Conference on Harmonisation guidance, including limits of detection and quantification, ranges, recovery and precision. Due to improved instrumental settings and work-up procedure, limits of detection and quantification ranged between 8.0-202.0pg/mL and 28.0-674pg/mL, respectively. Recovery data in five calibration points varied between 91.9% and 116.8% and in serum samples between 93.1% and 118.1%. The mean coefficient of variation (CV) for the recovery of all compounds was <10%. Well satisfying CVs for within-day precision (2.1-10.8%) and for between-day precision (2.3-12.1%) were obtained. More than 20 samples could be processed in a single routine day and test series of about 300 samples can be realised without impairment of the validation parameters during a sequence. Comparison of oxysterol and oxyphytosterol content in serum and plasma revealed no difference. A fully validated isotope dilution methodology for the quantification of oxycholesterols and oxyphytosterols from human serum or plasma is presented.

Topics: Calibration; Cholesterol; Gas Chromatography-Mass Spectrometry; Humans; Hydrolysis; Indicator Dilution Techniques; Isotopes; Limit of Detection; Phytosterols; Reference Standards; Reproducibility of Results; Serum; Sitosterols; Solutions; Solvents; Time Factors

Structures of some bioactive phytochemicals in bran extract of the black rice cv. Riceberry that had demonstrated anti-cancer activity in leukemic cell line were investigated. After saponification with potassium hydroxide, separation of the unsaponified fraction by reversed-phase high performance liquid chromatography (HPLC) resulted in four sub-fractions that had a certain degree of anti-proliferation against a mouse leukemic cell line (WEHI-3 cell), this being IC50 at 24 h ranging between 2.80-467.11 μg/mL. Further purification of the bioactive substances contained in these four sub-fractions was performed by normal-phase HPLC. Structural characterization by gas chromatography-mass spectrometry (GC-MS), liquid chromatography-mass spectrometry (LC-MS) and nuclear magnetic resonance spectroscopy (NMR) resulted in, overall, the structures of seven phytosterols and four triterpenoids. Four phytosterols, 24-methylene-ergosta-5-en-3β-ol, 24-methylene-ergosta-7-en-3β-ol, fucosterol, and gramisterol, along with three triterpenoids, cycloeucalenol, lupenone, and lupeol, were found in the two sub-fractions that showed strong anti-leukemic cell proliferation (IC50 = 2.80 and 32.89 μg/mL). The other sterols and triterpenoids were campesterol, stigmasterol, β-sitosterol and 24-methylenecycloartanol. Together with the data from in vitro biological analysis, we suggest that gramisterol is a significant anti-cancer lead compound in Riceberry bran extract.

Topics: Animals; Antineoplastic Agents, Phytogenic; Cell Line, Tumor; Cholesterol; Chromatography, High Pressure Liquid; Gas Chromatography-Mass Spectrometry; Leukemia; Mass Spectrometry; Mice; Molecular Structure; Oryza; Pentacyclic Triterpenes; Phytosterols; Phytotherapy; Plant Extracts; Seeds; Sitosterols; Stigmasterol; Triterpenes

The aim of the study was to evaluate the relationship between phytosterols, oxyphytosterols, and other markers of cholesterol metabolism and concomitant coronary artery disease (CAD) in patients with severe aortic stenosis who were scheduled for elective aortic valve replacement. Markers of cholesterol metabolism (plant sterols and cholestanol as markers of cholesterol absorption and lathosterol as an indicator of cholesterol synthesis) and oxyphytosterols were determined in plasma and aortic valve tissue from 104 consecutive patients with severe aortic stenosis (n=68 statin treatment; n=36 no statin treatment) using gas chromatography-flame ionization and mass spectrometry. The extent of CAD was determined by coronary angiography prior to aortic valve replacement. Patients treated with statins were characterized by lower plasma cholesterol, cholestanol, and lathosterol concentrations. However, statin treatment did not affect the sterol concentrations in cardiovascular tissue. The ratio of campesterol-to-cholesterol was increased by 0.46±0.34μg/mg (26.0%) in plasma of patients with CAD. The absolute values for the cholesterol absorption markers sitosterol and campesterol were increased by 18.18±11.59ng/mg (38.8%) and 11.40±8.69ng/mg (30.4%) in the tissues from patients with documented CAD compared to those without concomitant CAD. Campesterol oxides were increased by 0.06±0.02ng/mg (17.1%) in the aortic valve cusps and oxidized sitosterol-to-cholesterol ratios were up-regulated by 0.35±0.2ng/mg (22.7%) in the plasma of patients with CAD. Of note, neither cholestanol nor the ratio of cholestanol-to-cholesterol was associated with CAD. Patients with concomitant CAD are characterized by increased deposition of plant sterols, but not cholestanol in aortic valve tissue. Moreover, patients with concomitant CAD were characterized by increased oxyphytosterol concentrations in plasma and aortic valve cusps.

Topics: Aged; Aortic Valve; Aortic Valve Stenosis; Blood Vessels; Cholestanol; Cholesterol; Coronary Artery Disease; Female; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Male; Oxidation-Reduction; Phytosterols; Sitosterols

Pharmacognostic evaluation of medicinal plants may assess their current applications and possibly results in finding new active components. In this study, ash and extractive values and high performance thin layer chromatography fingerprints of Alyssum homolocarpum (Brassicaceae) seed extracts were investigated to elucidate its composition. Differential scanning calorimetry and gas chromatography-mass spectrometry analysis were employed to determine the components of A. homolocarpum seed oil (AHO). Neurosphere assay, in vitro differentiation and immunofluorescence analysis were performed to evaluate the effects of oral administration of AHO (0.5 or 1 g/kg/day for 14 days) on proliferation and differentiation of neural stem cells (NSCs) in adult male BALB/c mice. Total, acid-insoluble and water-soluble ash values were determined as 45.83 ± 5.85, 6.67 ± 2.89 and 28.33 ± 2.89 mg/g, respectively. The extractive values were 4.90, 0.43 and 0.56 % (w/w) for n-hexane, dichloromethane and ethanolic extracts, respectively. Interestingly, AHO was mainly composed of α-linolenic acid (89.71 %), β-sitosterol (3.3 mg/g) and campesterol (0.86 mg/g). Administration of AHO at 1 g/kg/day significantly increased proliferation of NSCs, as evidenced by an increase in mean neurosphere-forming frequency per brain (872.7 ± 15.17) and neurosphere diameter (101 ± 2.48 µm) compared to the control group (424.3 ± 59.29 and 78.63 ± 1.7 µm, respectively; P < 0.05). AHO treatment did not affect in vitro differentiation of the harvested NSCs. Our data show that A. homolocarpum seed oil is a rich source of α-linolenic acid and β-sitosterol with potential therapeutic application to enhance NSC proliferation and recruitment in neurological diseases.

Topics: Animals; Brassicaceae; Cell Differentiation; Cell Proliferation; Cells, Cultured; Cholesterol; Drug Evaluation, Preclinical; Gas Chromatography-Mass Spectrometry; Male; Mice; Mice, Inbred BALB C; Neural Stem Cells; Phytosterols; Plant Extracts; Plant Oils; Seeds; Sitosterols

We performed comparative DSC and FTIR spectroscopic measurements of the effects of β-sitosterol (Sito) and stigmasterol (Stig) on the thermotropic phase behavior and organization of DPPC bilayers. Sito and Stig are the major sterols in the biological membranes of higher plants, whereas cholesterol (Chol) is the major sterol in mammalian membranes. Sito differs in structure from Chol in having an ethyl group at C24 of the alkyl side-chain, and Stig in having both the C24 ethyl group and trans-double bond at C22. Our DSC studies indicate that the progressive incorporation of Sito and Stig decrease the temperature and cooperativity of the pretransition of DPPC to a slightly lesser and greater extent than Chol, respectively, but the pretransition persists to 10 mol % sterol concentration in all cases. All three sterols produce essentially identical effects on the thermodynamic parameters of the sharp component of the DPPC main phase transition. However, the ability to increase the temperature and decrease the cooperativity and enthalpy of the broad component decreases in the order Chol>Sito>Stig. Nevertheless, at higher Sito/Stig concentrations, there is no evidence of sterol crystallites. Our FTIR spectroscopic studies demonstrate that Sito and especially Stig incorporation produces a smaller ordering of the hydrocarbon chains of fluid DPPC bilayers than does Chol. In general, the presence of a C24 ethyl group in the alkyl side-chain reduces the characteristic effects of Chol on the thermotropic phase behavior and organization of DPPC bilayer membranes, and a trans-double bond at C22 magnifies this effect.

Topics: 1,2-Dipalmitoylphosphatidylcholine; Calorimetry, Differential Scanning; Cholestadienols; Cholesterol; Lipid Bilayers; Molecular Structure; Phase Transition; Phytosterols; Sitosterols; Spectroscopy, Fourier Transform Infrared; Stigmasterol; Temperature

Flaxseed (Linum usitatissimum L.) oil was obtained via subcritical n-propane fluid extraction (SubFE) under different temperatures and pressures with an average yield of 28% and its composition, purity and oxidative stability were compared to oils obtained via conventional solvent extraction methods (SEMs). When the oxidative stability was measured by differential scanning calorimetry, the oil was found to be up to 5 times more resistant to lipid oxidation as compared to the SEM oils. Direct infusion electrospray ionization mass spectrometry (ESI-MS) analysis showed characteristic and similar TAG profiles for SubFE and SEMs oils but higher purity for the SubFE oil. The flaxseed oil content of β-tocopherol, campesterol, stigmasterol and sitosterol were quantified via GC-MS. SubFE showed to be a promising alternative to conventional SEM since SubFE provides an oil with higher purity and higher oxidation stability and with comparable levels of biologically active components.

Topics: beta-Tocopherol; Calorimetry, Differential Scanning; Chemical Fractionation; Cholesterol; Gas Chromatography-Mass Spectrometry; Linseed Oil; Oxidation-Reduction; Phytosterols; Pressure; Principal Component Analysis; Propane; Sitosterols; Spectrometry, Mass, Electrospray Ionization; Stigmasterol; Temperature

The regulated physicochemical quality parameters (free acidity, peroxide value and UV absorption characteristics), sensory parameters (median of fruity, median of defect, panel classification, bitterness and pungency), stability parameters (total phenols and oxidative stability at 100°C) and chemical composition (fatty acids, sterols and triterpenic dialcohols) of virgin olive oils obtained from 12 olive varieties cultivated in 6 of the most representative zones of Castilla-La Mancha (La Alcarria, Campos de Calatrava, Campos de Hellín, Campos de Montiel, Montes de Toledo and Sierra de Alcaraz) were evaluated. The varieties Cornicabra and Picual showed remarkable total polyphenols content and high stability, in contrast with Arbequina. The other less common varieties were in-between these two groups. Cornicabra and Picual showed also high oleic and low linoleic acids content, while Arbequina showed low oleic, high linoleic high palmitic and high palimitoleic acid content. The varieties Benizal and Cornicabra showed very high campesterol content. Benizal stood out by its high stigmasterol, low apparent β-sitosterol and low total sterols content, and the latter was below the established limit for olive oil. Triterpenic dialcohol content was significantly lower for Arbequina than for Cornicabra.

Topics: Absorption, Radiation; Chemical Phenomena; Cholesterol; Fatty Acids; Food Quality; Linoleic Acid; Oleic Acid; Olive Oil; Oxidation-Reduction; Palmitic Acid; Peroxides; Phytosterols; Polyphenols; Spain; Sterols; Taste; Triterpenes; Ultraviolet Rays

To evaluate the association between very low density lipoprotein cholesterol (VLDL-C) and cholesterol absorption and synthesis markers in patients with moderate and high risk of coronary heart disease.. A total 363 statin-naïve patients with moderate and high risk of coronary heart disease were consecutively recruited from two hospitals in Shanxi and Henan provinces between October 2008 and June 2009. A standard questionnaire and physical examination were performed at baseline. Atorvastatin (20 mg/day) was administered to patients for 4 weeks. Venous blood samples after an overnight fast were collected before and after treatment for measuring VLDL-C and cholesterol absorption and synthesis markers. In qualitative analyses, the baseline level of cholesterol absorption and synthesis markers and their reduction after atorvastatin treatment were categorized into 3 tertile groups.. (1) Of 363 patients, 283 patients with mean age of (55.43±9.01)years old with complete data were finally analyzed. The median level of baseline VLDL-C was 1.06 (0.65, 1.86) mmol/L. The median level of baseline cholesterol absorption marker (Campesterol) and cholesterol synthesis marker (Lathosterol) was 6.01 (3.78, 9.45) mg/L and 13.46 (8.30, 21.07) mg/L, respectively. (2) Partial correlation analysis and multiple regression showed the baseline level of VLDL-C was positively correlated with Campesterol (r=0.153, P<0.05) but not with Lathosterol(r=0.182, P=0.173). Furthermore, baseline VLDL-C level significantly increased with tertile of the baseline level of Campesterol in the qualitative analyses(P for trend=0.035). (3) Mean reduction in VLDL-C levels was 38.0% after 4 weeks atorvastatin treatment. VLDL-C reduction was positively correlated with Campesterol reduction (r=0.331, P<0.001). VLDL-C reduction significantly increased with the tertile of Campesterol reduction (P for trend=0.032). But this trend was not observed between VLDL-C level and Lathosterol (P for trend=0.798).. The level of VLDL-C was closely related to cholesterol absorption marker, and further studies are needed to validate if inhibitor of cholesterol absorption (for example by Ezetimibe) could bring about more effective VLDL-C lowering effect in this patient cohort.

Topics: Atorvastatin; Biomarkers; Cholesterol; Cholesterol, LDL; Cholesterol, VLDL; Coronary Artery Disease; Ezetimibe; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Phytosterols; Risk Factors

The analysis of blood for β-sitosterol and campesterol is the measures of cholesterol absorption while lathosterol is a measure of cholesterol synthesis.. The biological variability of β-sitosterol, campesterol, and lathosterol was measured using liquid-chromatography tandem mass spectrometry from a cohort of 25 apparently healthy subjects, where blood was taken once every weeks for 6 weeks. The analytical, intra-individual, and group inter-individual variations (CVA, CV(I), and CV(G), respectively) were calculated.. Using absolute values, the CVI for β-sitosterol, campesterol, and lathosterol was 11.8%, 11.8%, and 22.5%, respectively, and the CV(G) was 28.5%, 28.8%, and 52.0%, respectively. This produced reference change values of about 24-36% for declining values and 32-47% for increasing values. The index of individuality was between 0.41 and 0.58, indicating that population based reference values are of little use for these biomarkers. The number of points needed for a homeostatic setpoint was 5 samples for β-sitosterol and campesterol, and 19 samples for lathosterol. Similar findings were observed for values when normalized to total cholesterol. These results were higher than the biological variation for total, low density and high density cholesterol obtained from the literature. Results were essentially identical when sterol values were corrected to their respective total cholesterol concentration.. The establishment of the biological variation for these biomarkers enables their use in the interpretation of results from clinical trials and lipid lowering treatment of patients at risk for cardiovascular disease in clinical practice.

Topics: Absorption, Physicochemical; Biomarkers; Cholesterol; Humans; Phytosterols; Sitosterols

Ross Lake lies within the City of Flin Flon (Manitoba, Canada), a mining community originally formed by the Hudson Bay Mining and Smelting Company (now Hudbay Minerals Inc.) in 1927. At the time of this investigation, a continuous effluent stream from Hudbay Minerals (approximately 80 years) and a discontinuous and unknown amount of raw and minimally treated municipal sewage (>20 years, likely ending in 1951) was discharged into the north basin of the lake. Maximum concentrations of fecal sterols, such as coprostanol and terrestrial phytosterols, such as: β-sitosterol, campesterol, stigmastanol were measured in vertical sections of sediment cores, collected from Ross Lake, in the 15-16-cm section, which likely corresponds to the 1930s. Concentrations of coprostanol increased from <1 μg g(-1) in older sediments, to 252.3 μg g(-1) organic carbon at the peak. Observed changes in concentrations of sterols, in combination with radiometric dating and changes to sediment physicochemical characteristics, support the conclusion that sediments of a depth of less than 17.5-cm depth were deposited during the post-industrial era from approximately 1930 onwards. Ratios of coprostanol to cholesterol>1, peaking at 3.6 are consistent with anecdotal information that municipal sewage was discharged into Ross Lake during the early years of urbanization, prior to changes in treatment of sewage and discharge practices that began in 1951. Finally, historical concentrations of terrestrial phytosterols followed trends similar to those of coprostanol and cholesterol and may possibly be the result of an increase in the flux of terrestrial organic matter into Ross Lake as the result of regional deforestation due to logging and fire.

Topics: Cholesterol; Environmental Monitoring; Feces; Geologic Sediments; History, 20th Century; History, 21st Century; Lakes; Manitoba; Phytosterols; Sewage; Sitosterols; Waste Disposal, Fluid; Water Pollutants; Water Purification

Retama monosperma L. (Boiss.) or Genista monosperma L. (Lam.), locally named as "R'tam", is an annual and spontaneous plant belonging to the Fabaceae family. In Morocco, Retama genus is located in desert regions and across the Middle Atlas and it has been widely used in traditional medicine in many countries. In this study, we show that Retama monosperma hexane extract presents significant anti-leukemic effects against human Jurkat cells.. Human Jurkat cells, together with other cell lines were screened with different concentrations of Retama monosperma hexane extract at different time intervals. Growth inhibition was determined using luminescent-based viability assays. Cell cycle arrest and apoptosis were measured by flow cytometry analysis. Combined caspase 3 and 7 activities were measured using luminometric caspase assays and immunoblots were performed to analyze expression of relevant pro- and anti-apoptotic proteins. GC-MS were used to determine the chemical constituents of the active extract.. Retama monosperma hexane extract (Rm-HE) showed significant cytotoxicity against Jurkat cells, whereas it proved to be essentially ineffective against both normal mouse fibroblasts (NIH3T3) and normal lymphocytes (TK-6). Cytometric analysis indicated that Rm-HE promoted cell cycle arrest and apoptosis induction accompanied by DNA damage induction indicated by an increase in p-H2A.X levels. Rm-HE induced apoptosis was partially JNK-dependent and characterized by an increase in Fas-L levels together with activation of caspases 8, 3, 7 and 9, whereas neither the pro-apoptotic nor anti-apoptotic mitochondrial membrane proteins analyzed were significantly altered. Chemical identification analysis indicated that α-linolenic acid, campesterol, stigmasterol and sitosterol were the major bioactive components within the extract.. Our data suggest that bioactive compounds present in Rm-HE show significant anti leukemic activity inducing cell cycle arrest and cell death that operates, at least partially, through the extrinsic apoptosis pathway.

Topics: alpha-Linolenic Acid; Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Apoptosis Regulatory Proteins; Caspase 3; Caspases; Cell Cycle Checkpoints; Cell Death; Cell Proliferation; Cholesterol; Fabaceae; Fas Ligand Protein; Humans; Jurkat Cells; Leukemia, T-Cell; MAP Kinase Kinase 4; Mice; NIH 3T3 Cells; Phytosterols; Phytotherapy; Plant Extracts; Signal Transduction; Sitosterols; Stigmasterol

New and sustainable sources of long-chain (LC, ≥C₂₀) omega-3 oils containing DHA (docosahexaenoic acid, 22:6ω3) are required to meet increasing demands. The lipid content of the oilseed of a novel transgenic, DHA-producing land plant, Camelina sativa, containing microalgal genes able to produce LC omega-3 oils, contained 36% lipid by weight with triacylglycerols (TAG) as the major lipid class in hexane extracts (96% of total lipid). Subsequent chloroform-methanol (CM) extraction recovered further lipid (~50% polar lipid, comprising glycolipids and phospholipids) and residual TAG. The main phospholipid species were phosphatidyl choline and phosphatidyl ethanolamine. The % DHA was: 6.8% (of total fatty acids) in the TAG-rich hexane extract and 4.2% in the polar lipid-rich CM extract. The relative level of ALA (α-linolenic acid, 18:3ω3) in DHA-camelina seed was higher than the control. Major sterols in both DHA- and control camelina seeds were: sitosterol, campesterol, cholesterol, brassicasterol and isofucosterol. C₁₆-C₂₂ fatty alcohols, including iso-branched and odd-chain alcohols were present, including high levels of iso-17:0, 17:0 and 19:0. Other alcohols present were: 16:0, iso-18:0, 18:0 and 18:1 and the proportions varied between the hexane and CM extracts. These iso-branched odd-chain fatty alcohols, to our knowledge, have not been previously reported. These components may be derived from wax esters, or free fatty alcohols.

Topics: Brassicaceae; Cholestadienols; Cholesterol; Fatty Acids, Omega-3; Gas Chromatography-Mass Spectrometry; Phospholipids; Phytosterols; Plant Oils; Plants, Genetically Modified; Seeds; Sitosterols; Stigmasterol; Triglycerides

Phytosterols such as campesterol and sitosterol are susceptible to oxidation by reactive oxygen species. We hypothesize that the plant sterols (PS) campesterol and sitosterol and their 7-oxygenated metabolites (POPs) correlate within and between human plasma and aortic valve cusps tissues. Plasma and tissue concentrations of PS and POPs were analyzed by gas chromatography-mass spectrometry-selected ion monitoring. Prior to analysis valve cusps tissue was mechanically separated from the calcified parts. PS and POP levels per dry cusps tissue weight were significantly higher compared with the concentrations in the calcified part. Against our hypothesis we found that despite the fact that there is a high correlation between plant sterols in and between plasma and valves cusps tissue, as well as a high correlation between plant sterols and oxyphytosterols and oxyphytosterols themselves within the valve cusps tissue, there was hardly any correlation in the amount of oxyphytosterols in plasma and between plasma and valves. Because plasma samples are easily accessible for large scale population based studies, we have to understand in more detail what the analysis of POPs implies in terms of CVD risk for the future.

Topics: Adult; Aged; Aged, 80 and over; Aortic Valve; Aortic Valve Stenosis; Cholesterol; Female; Humans; Male; Middle Aged; Phytosterols; Sitosterols

The modifications of cholesterol metabolism associated with aging are ill-defined. The objective of this study was to define age-associated alterations of the different metabolic pathways controlling cholesterol homeostasis by analyzing circulating sterols.. We analyzed serum samples collected from 201 adult (75 male, 126 female) subjects within the epidemiological MICOL study (Multicentrica Italiana Colelitiasi). The age range was 38-79 years; 103 had evidence of gallstones. The concentrations of the different sterols, recognized as markers of the main pathways of cholesterol homeostasis, were analyzed by gas chromatography-mass spectrometry, including lathosterol (synthesis), campesterol and sitosterol (absorption), and 7α-hydroxy-4-cholesten-3-one (degradation to bile acids).. A significant direct correlation was detected between age and cholesterol levels (r =0.34, P<0.01). The lathosterol/cholesterol ratio was lower in older age quartiles (P<0.05 by analysis of variance), with an inverse correlation between the lathosterol/cholesterol ratio and age (r=-0.32, P<0.01). Such correlation was particularly evident in females. The campesterol/cholesterol and sitosterol/cholesterol ratios were inversely correlated with aging in control, but not in gallstone patients. The levels of 7α-hydroxy-4-cholesten-3-one were not correlated with age.. These data show a reduction of cholesterol synthesis with aging which is associated with increased circulating cholesterol levels. The finding might be related to a reduced metabolic need for cholesterol in advancing age, leading to a downregulation of the main mechanisms of cholesterol intake in the liver. A different age-related behavior was observed in gallstone-free versus gallstone patients regarding cholesterol absorption. The possible implications in terms of the pharmacological management of hypercholesterolemia in the elderly remain to be defined.

Topics: Adult; Age Factors; Aged; Aging; Cholestenones; Cholesterol; Cross-Sectional Studies; Female; Gallstones; Gas Chromatography-Mass Spectrometry; Homeostasis; Humans; Italy; Male; Middle Aged; Phytosterols; Sitosterols

We present a comparative differential scanning calorimetric study of the effects of the animal sterol cholesterol (Chol) and the plant sterols campesterol (Camp) and brassicasterol (Bras) on the thermotropic phase behavior of dipalmitoylphosphatidylcholine (DPPC) bilayers. Camp and Bras differ from Chol in having a C24 methyl group and, additionally for Bras, a C22 trans-double bond. Camp and especially Bras decrease the temperature, cooperativity and enthalpy of the DPPC pretransition more than Chol, although these effects are attenuated at higher sterol levels. This indicates that they destabilize gel-state DPPC bilayers to a greater extent, but are less soluble, than Chol. Not surprisingly, all three sterols have similar effects on the sterol-poor sharp component of the DPPC main phase transition. However, Camp and especially Bras less effectively increase the temperature and decrease the cooperativity and enthalpy of the broad component of the main transition than Chol. This indicates that at higher sterol concentrations, Camp and Bras are less miscible and less effective than Chol at ordering the hydrocarbon chains of the sterol-enriched fluid DPPC bilayers. Overall, these alkyl side chain modifications generally reduce the ability of Chol to produce its characteristic effects on DPPC bilayer physical properties. These differences are likely due to the less extended and more bent conformations of the alkyl side chains of Camp and Bras, producing sterols with a greater effective cross-sectional area and reduced length than Chol. Hence, the structure of Chol is likely optimized for maximum solubility in, as opposed to maximum ordering of, phospholipid bilayers.

Topics: 1,2-Dipalmitoylphosphatidylcholine; Calorimetry, Differential Scanning; Cholestadienols; Cholesterol; Lipid Bilayers; Membranes; Models, Molecular; Phase Transition; Phytosterols; Temperature

Phytosterols are plant-derived sterols present in pulp and paper wastewater and have been implicated in the endocrine disruption of aquatic species. Bioassays were performed to assess the effect of an additional carbon source and/or solubilizing agent on the aerobic biotransformation of a mixture of three common phytosterols (β-sitosterol, stigmasterol and campesterol). The aerobic biotransformation of the phytosterol mixture by a mixed culture developed from a pulp and paper wastewater treatment system was examined under three separate conditions: with phytosterols as the sole added carbon source, with phytosterols and dextrin as an additional carbon source, and with phytosterols added with ethanol as an additional carbon source and solubilizing agent. Significant phytosterol removal was not observed in assays set up with phytosterol powder, either with or without an additional carbon source. In contrast, all three phytosterols were aerobically degraded when added as a dissolved solution in ethanol. Thus, under the experimental conditions of this study, the bioavailability of phytosterols was limited without the presence of a solubilizing agent. The total phytosterol removal rate was linear for the first six days before re-spiking, with a rate of 0.47 mg/L-d (R(2) = 0.998). After the second spiking, the total phytosterol removal rate was linear for seven days, with a rate of 0.32 mg/L-d (R(2) = 0.968). Following the 7th day, the phytosterol removal rate markedly accelerated, suggesting two different mechanisms are involved in phytosterol biotransformation, more likely related to the production of enzyme(s) involved in phytosterol degradation, induced under different cell growth conditions. β-sitosterol was preferentially degraded, as compared to stigmasterol and campesterol, although all three phytosterols fell below detection limits by the 24th day of incubation.

Topics: Bacteria, Aerobic; Biodegradation, Environmental; Biotechnology; Biotransformation; Carbon; Cholesterol; Dextrins; Ethanol; Phytosterols; Sitosterols; Stigmasterol; Water Pollutants, Chemical

Withanolides biosynthesis in the plant Withania somnifera (L.) Dunal is hypothesized to be diverged from sterol pathway at the level of 24-methylene cholesterol. The conversion and translocation of intermediates for sterols and withanolides are yet to be characterized in this plant. To understand the influence of mevalonate (MVA) and 2-C-methyl-d-erythritol-4-phosphate (MEP) pathways on sterols and withanolides biosynthesis in planta, we overexpressed the WsHMGR2 and WsDXR2 in tobacco, analyzed the effect of transient suppression through RNAi, inhibited MVA and MEP pathways and fed the leaf tissue with different sterols. Overexpression of WsHMGR2 increased cycloartenol, sitosterol, stigmasterol and campesterol compared to WsDXR2 transgene lines. Increase in cholesterol was, however, marginally higher in WsDXR2 transgenic lines. This was further validated through transient suppression analysis, and pathway inhibition where cholesterol reduction was found higher due to WsDXR2 suppression and all other sterols were affected predominantly by WsHMGR2 suppression in leaf. The transcript abundance and enzyme analysis data also correlate with sterol accumulation. Cholesterol feeding did not increase the withanolide content compared to cycloartenol, sitosterol, stigmasterol and campesterol. Hence, a preferential translocation of carbon from MVA and MEP pathways was found differentiating the sterols types. Overall results suggested that MVA pathway was predominant in contributing intermediates for withanolides synthesis mainly through the campesterol/stigmasterol route in planta.

Topics: Base Sequence; Biosynthetic Pathways; Carbon; Cholesterol; Erythritol; Gene Expression; Gene Expression Regulation, Plant; Mevalonic Acid; Molecular Sequence Data; Nicotiana; Phylogeny; Phytosterols; Plant Leaves; Plant Proteins; Plants, Genetically Modified; Sequence Analysis, DNA; Sitosterols; Sterols; Stigmasterol; Sugar Phosphates; Triterpenes; Withania; Withanolides

The efficacy and safety of plant stanols added to food products as serum cholesterol lowering agents have been demonstrated convincingly, but their effects on cholesterol metabolism and on serum non-cholesterol sterols is less evaluated. The aim of this study was to assess the validity of serum non-cholesterol sterols and squalene as bioindices of cholesterol synthesis and absorption, and to examine how the individual serum non-cholesterol sterols respond to consumption of plant stanols.. We collected all randomized, controlled plant stanol ester (STAEST) interventions in which serum cholestanol, plant sterols campesterol and sitosterol, and at least two serum cholesterol precursors had been analysed. According to these criteria, there was a total of 13 studies (total 868 subjects without lipid-lowering medication; plant stanol doses varied from 0.8 to 8.8 g/d added in esterified form; the duration of the studies varied from 4 to 52 weeks). Serum non-cholesterol sterols were assayed with gas-liquid chromatography, cholesterol synthesis with the sterol balance technique, and fractional cholesterol absorption with the dual continuous isotope feeding method.. The results demonstrated that during the control and the STAEST periods, the serum plant sterol/cholesterol- and the cholestanol/cholesterol-ratios reflected fractional cholesterol absorption, and the precursor sterol/cholesterol-ratios reflected cholesterol synthesis. Plant sterol levels were dose-dependently reduced by STAEST so that 2 g of plant stanols reduced serum campesterol/cholesterol-ratio on average by 32%. Serum cholestanol/cholesterol-ratio was reduced less frequently than those of the plant sterols by STAEST, and the cholesterol precursor sterol ratios did not change consistently in the individual studies emphasizing the importance of monitoring more than one surrogate serum marker.. Serum non-cholesterol sterols are valid markers of cholesterol absorption and synthesis even during cholesterol absorption inhibition with STAEST. Serum plant sterol concentrations decrease dose-dependently in response to plant stanols suggesting that the higher the plant stanol dose, the more cholesterol absorption is inhibited and the greater the reduction in LDL cholesterol level is that can be achieved.. Clinical Trials Register # NCT00698256 [Eur J Nutr 2010, 49:111-117].

Topics: Adult; Aged; Cholestanol; Cholesterol; Female; Humans; Hypercholesterolemia; Hypolipidemic Agents; Male; Middle Aged; Phytosterols; Randomized Controlled Trials as Topic; Sitosterols; Sterols; Young Adult

Lopezia racemosa Cav. is a plant used in Mexican traditional medicine to heal inflammatory diseases. From this plant we isolated the novel compound 6-O-palmitoyl- 3-O-β-D-glucopyranosylcampesterol (1) and 6-O-palmitoyl-3-O-β-D-glucopyranosyl-β-sitosterol (2), previously reported to have cytotoxic activity on several cancer cell lines. We evaluated the anti-inflammatory activity of 1 in vivo by mouse ear edema induced with 12-O-tetradecanoylphorbol-13-acetate (TPA) and 57.14% inhibition was observed. The aim of our study was to obtain callus cultures derived from this plant species with the ability to produce the compounds of interest. Callus cultures were initiated on MS basal medium amended with variable amounts of naphthaleneacetic acid (NAA), or 2,4-dichlorophenoxyacetic acid (2,4-D), combined or not with 6-benzylaminopurine (BAP). Ten treatments with these growth regulators were carried out, using in vitro germinated seedlings as source of three different explants: hypocotyl, stem node, and leaf. Highest yield of 1 was observed on callus derived from leaf explants growing in medium containing 1.0 mg/L 2,4-D and 0.5 mg/L BAP. Selected callus lines produced less 1 than wild plants but the in vitro cultured seedlings showed higher production. So we conclude that it could be attractive to further investigate their metabolic potential.

Topics: Animals; Anti-Inflammatory Agents; Cells, Cultured; Cholesterol; Ear; Edema; Germination; Inflammation; Male; Mice; Onagraceae; Phytochemicals; Phytosterols; Plant Extracts; Seeds; Tetradecanoylphorbol Acetate

A new method, reversed phase liquid chromatography with off-line surface-assisted laser desorption/ionization mass spectrometry (RPLC-SALDI MS) for the determination of brassicasterol (BR), cholesterol (CH), stigmasterol (ST), campesterol (CA) and β-sitosterol (SI) in oil samples has been developed. The sample preparation consisted of alkaline saponification followed by extraction of the unsaponificable fraction with diethyl ether. The recovery of the sterols ranged from 91 to 95% with RSD less than 4%. Separation of the five major sterols on a C18 column using methanol-water gradient was achieved in about 10min. An on-line UV detector was employed for the initial sterol detection prior to effluent deposition using a laboratory-built spotter with 1:73 splitter. Off-line SALDI MS was then applied for mass determination/identification and quantification of the separated sterols. Ionization of the nonpolar analytes was achieved by silver ion cationization with silver nanoparticles used as the SALDI matrix providing limits of detection 12, 6 and 11fmol for CH, ST and SI, respectively. Because of the incorporated splitter, the effective limits of detection of the RPLC-SALDI MS analysis were 4, 3 and 4pmol (or 0.08, 0.06 and 0.08μg/mL) for CH, ST and SI, respectively. For quantification, 6-ketocholestanol (KE) was used as the internal standard. The method has been applied for the identification and quantification of sterols in olive, linseed and sunflower oil samples. The described off-line coupling of RPLC to SALDI MS represents an alternative to GC-MS for analysis of nonpolar compounds.

Topics: Cholestadienols; Cholesterol; Chromatography, Reverse-Phase; Ketocholesterols; Linseed Oil; Olive Oil; Phytosterols; Plant Oils; Reference Standards; Silver; Sitosterols; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Stigmasterol; Sunflower Oil

This study has determined oil, fatty acid (FA) and phytosterols content during the ripening of the Tunisian Onopordum acanthium L. seeds. In total, nine FAs and six phytosterols were identified. The main FAs were linoleic acid (0.18-8.06 mg/g of seed) followed by oleic acid (0.051-2.45 mg/g of seed), palmitic acid and stearic acid. Pentadecanoic acid was detected, for the first time, in unripe fruits and the two last stages of development were characterised by a relative abundance of erucic acid. Overall, β-sitosterol (34.5-77.79% of total sterols) was the major 4-desmethylsterols during maturation. The first episodes of growth were characterised by the best amounts of stigmasterol and campesterol, while stigmastanol and Δ7 sitosterol had quoted the semi-ripe and fully ripe fruits; however, cholesterol was absent. These findings are useful in understanding a potential new source of important natural compounds (Phytosterols and USFA) found in this fruit and when harvest should be undertaken to optimise desired FA and phytosterols content.

Topics: Cholesterol; Fatty Acids; Fruit; Linoleic Acid; Oleic Acid; Onopordum; Phytosterols; Plant Oils; Seeds; Sitosterols; Stigmasterol; Tunisia

The effects of ezetimibe on cholesterol metabolism in HIV-infected patients receiving boosted protease inhibitors have not been thoroughly assessed. The aim of this study was to assess cholesterol homeostasis in patients with PI associated dyslipidemia and its relationship with the response to treatment with the cholesterol-absorption inhibitor ezetimibe.. Fifteen patients with ritonavir-boosted PI-containig therapy and LDL-cholesterol > 3.36 mmol/L (>130 mg/dL) were assessed at baseline and after an 8-week course of ezetimibe 10 mg/d. Serum non-cholesterol sterols were measured at each visit as markers of cholesterol synthesis and absorption. Total-, LDL-, and HDL-cholesterol triglycerides, apolipoproteins A1 and B, high sensitivity C-reactive protein, CD4 cells and HIV-1 RNA were also measured.. Ezetimibe treatment was well tolerated in all patients and resulted in significant reductions in total cholesterol (-11.4%, p = .002), LDL-cholesterol (-20.4%, p = .003), non-HDL-cholesterol (-13.4%, p = .002) and apolipoprotein B (-9.1%, p = .021). Treatment with ezetimibe was associated with decreased cholesterol absorption markers (campesterol-to-cholesterol ratio -43.0%, p = .001; sitosterol-to-cholesterol ratio -41.9%, p = .001) and increased synthesis markers (lathosterol-to-cholesterol ratio 53.2%, p = .005). Baseline absorption or synthesis markers were unrelated to the response to treatment. CD4 cell count and plasma HIV-1 RNA remained unchanged.. The level of cholesterol absorption or synthesis does not appear to be a major determinant of the responsiveness to ezetimibe in patients on ritonavir-boosted PI-containing therapy.. EudraCT: 2006-006156-36.

Topics: Adult; Aged; Anticholesteremic Agents; Azetidines; C-Reactive Protein; Cholesterol; Cholesterol, LDL; Dyslipidemias; Ezetimibe; Female; HIV Infections; Humans; Lipid Metabolism; Male; Middle Aged; Phytosterols; Protease Inhibitors

Potatoes (Solanum tuberosum) contain α-solanine and α-chaconine, two well-known toxic steroidal glycoalkaloids (SGAs). Sprouts and green tubers accumulate especially high levels of SGAs. Although SGAs were proposed to be biosynthesized from cholesterol, the biosynthetic pathway for plant cholesterol is poorly understood. Here, we identify sterol side chain reductase 2 (SSR2) from potato as a key enzyme in the biosynthesis of cholesterol and related SGAs. Using in vitro enzyme activity assays, we determined that potato SSR2 (St SSR2) reduces desmosterol and cycloartenol to cholesterol and cycloartanol, respectively. These reduction steps are branch points in the biosynthetic pathways between C-24 alkylsterols and cholesterol in potato. Similar enzymatic results were also obtained from tomato SSR2. St SSR2-silenced potatoes or St SSR2-disrupted potato generated by targeted genome editing had significantly lower levels of cholesterol and SGAs without affecting plant growth. Our results suggest that St SSR2 is a promising target gene for breeding potatoes with low SGA levels.

Topics: Alkaloids; Biosynthetic Pathways; Cholesterol; Enzyme Assays; Gene Silencing; Genes, Plant; Molecular Sequence Data; Oxidoreductases; Phylogeny; Phytosterols; RNA Editing; Solanum lycopersicum; Solanum tuberosum; Tetraploidy

Nowadays, data concerning the composition of Caryodendron orinocense Karst. (Euphorbiaceae) and Bactris gasipaes Kunth (Arecaceae) seed oils are lacking. In light of this fact, in this paper fatty acids and unsaponifiable fraction composition have been determined using GC-MS, HPLC-DAD (Diode Array Detector), NMR approaches and possible future applications have been preliminary investigated through estimation of antioxidant activity, performed with DPPH test. For C. orinocense linoleic acid (85.59%) was the main component, lauric (33.29%) and myristic (27.76%) acids were instead the most abundant in B. gasipaes. C. orinocense unsaponifiable fraction (8.06%) evidenced a remarkable content of β-sitosterol, campesterol, stigmasterol, squalene and vitamin E (816 ppm). B. gasipaes revealed instead β-sitosterol and squalene as main constituents of unsaponifiable matter (3.01%). Antioxidant capacity evidenced the best performance of C. orinocense seed oil. These preliminary results could be interesting to suggest the improvement of the population's incomes from Amazonian basin. In particular the knowledge of chemical composition of C. orinocense and B. gasipaes oils could be helpful to divulge and valorize these autochthones plants.

Topics: Antioxidants; Arecaceae; Cholesterol; Chromatography, High Pressure Liquid; Euphorbiaceae; Fatty Acids; Free Radical Scavengers; Gas Chromatography-Mass Spectrometry; Lauric Acids; Linoleic Acid; Magnetic Resonance Spectroscopy; Myristic Acid; Nuts; Phytosterols; Plant Oils; Seeds; Sitosterols; Squalene; Stigmasterol; Vitamin E

Thyroid hormone reduces plasma cholesterol and increases expression of low-density lipoprotein receptor (LDL-R) in liver, an effect mediated by thyroid receptor β (TRβ). The selective TRβ modulator GC-1 also enhances several steps in reverse cholesterol transport and can decrease serum cholesterol independently of LDL-R. To test whether GC-1 reduces atherosclerosis and to determine which mechanisms are active, we treated ApoE deficient mice with atherogenic diet ± GC-1. GC-1 reduced cholesteryl esters in aorta after 20 weeks. Serum free and esterified cholesterol were reduced after 1 and 10 weeks, but not 20 weeks. Hepatic bile acid synthesis and LDL-R expression was elevated after 1, 10 and 20 weeks, without changes in hepatic de novo cholesterol synthesis. GC-1 increased faecal neutral sterols and reduced serum campesterol after 1 week, indicating reduced intestinal cholesterol absorption. After 20 weeks, GC-1 increased faecal bile acids, but not faecal neutral sterols. Hepatic scavenger receptor B1 (SR-B1) expression was decreased by GC-1. We conclude that GC-1 delays the onset of atherosclerosis in ApoE deficient mice. Since ApoE is needed for hepatic cholesterol reabsorption by LDL-R, this supports the idea that GC-1 reduces serum cholesterol independently of LDL-R by increasing hepatic bile acid synthesis. GC-1 lipid-lowering effects in ApoE deficient mice may also be partly due to reduced intestinal cholesterol absorption. Since reductions in serum cholesterol are reversed at longer times, these GC-1 dependent effects may not be enough for sustained cholesterol reduction in long term treatments.

Topics: Acetates; Animals; Aorta; Apolipoproteins E; Atherosclerosis; Bile Acids and Salts; Biological Transport; Cholesterol; Disease Models, Animal; Liver; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Phenols; Phytosterols; Receptors, LDL; Sterols; Thyroid Hormone Receptors beta; Time Factors

Gallstone disease is associated with p.D19H of ABCG8 as well as alterations of cholesterol and bile acid metabolism. However, molecular mechanisms have not been fully elucidated. It is important to understand the link between the sterol transporters ABCG5/8 and NPC1L1 and intestinal cholesterol absorption as well as de novo synthesis in gallstone patients stratified according to 19H risk allele. Moreover, the functional importance of the 19H variant on intestinal ABCG8 feature remains to be clarified.. Measurements of serum surrogate markers of cholesterol absorption (plant sterols: sitosterol, campesterol) and synthesis (cholesterol precursor: lathosterol) were carried out by gas chromatography/mass spectrometry (GC/MS). For expression studies, total RNA was isolated from 168 ileal biopsies of study participants with (34) and without gallstone disease (134). Messenger RNA was measured by LightCycler real-time PCR. Genomic DNA was obtained from blood leukocytes. Genotype frequencies of p.D19H were established using MALDI-TOF mass spectrometry.. Compared to controls, cholesterol absorption but not synthesis in gallstone carriers was diminished by about 21% based on low serum sitosterol (P = 0.0269) and campesterol (P = 0.0231) to cholesterol ratios. D19H was found to be significantly associated with gallstones (odds ratio [OR] = 2.9, P = 0.0220, 95% confidence interval [CI]:1.22-6.89), particularly in the overweight cohort (OR = 3.2, P = 0.0430, 95% CI:1.07-9.26). Cholesterol absorption was about 24% lower in individuals carrying p.D19H compared to wild type (Psitosterol = 0.0080, Pcampesterol = 0.0206). Moreover, irrespective of phenotype, carriers of p.D19H displayed a significant lower absorption than carriers of the major allele. The most pronounced effect on cholesterol absorption ratio was observed for serum campesterol levels (wild type controls to mutated controls 28%, P = 0.0347 and wild type controls to gallstone carriers with 19H allele 37%, P = 0.0030). Notably, ABCG5/8 and NPC1L1 expression was similar in gallstone carriers and controls regardless of p.D19H presence.. Both gallstone disease and p.D19H of ABCG8 are associated with diminished cholesterol absorption. However, p.D19H is not responsible for the differences in small intestinal sterol transporter expression.

Topics: Adult; Alleles; ATP Binding Cassette Transporter, Subfamily G, Member 8; ATP-Binding Cassette Transporters; Biopsy; Cholesterol; Female; Gallstones; Genetic Predisposition to Disease; Humans; Ileum; Intestinal Absorption; Male; Middle Aged; Phytosterols; Polymorphism, Genetic; Risk Factors; Sitosterols; Sterols

Phytosterols have been used alone, or combined with lipid-altering drugs, to reduce cholesterol levels and the burden of cardiovascular disease. Considerable variation in the composition of phytosterols exists and its consumption, in a regular diet, by the Brazilian population is still unknown. Thus, the aim of the present study was to determine the phytosterols content of the most consumed plant foods and to estimate the phytosterols intake by this population.. Intake of plant foods of a representative population of the city of São Paulo (n = 1609), randomly selected on the basis of the Brazilian Institute for Geography and Statistics census data (2010), was obtained by a food frequency questionnaire (FFQ). Foods were chosen on the basis of the Consume Expenditure Survey (2002-2003) and from answers to the FFQ. Phytosterols composition of most consumed greens, legumes, cereals, and seeds, fruits, and vegetable oils was determined by gas chromatography (flame ionization detection). Daily phytosterols intake was estimated in terms of mg per 100 g (mg/100 g(-1)) of edible portion. Underreporters and overreporters were excluded.. Mean (SE) daily phytosterols intake in the diet of the study population was 100.6 (1.2) mg, with β-sitosterol as the largest sterol component (65.4%), followed by campesterol (23.2%), and stigmasterol (10%). No significant changes in daily phytosterols intake were observed after exclusion of underreporters and overreporters. Considerable variation was observed in phytosterols content among the most consumed plant foods.. Analysis of phytosterols composition in most consumed plant foods has shown that phytosterols content varied among food groups. Dietary intake of phytosterols in a large population of the city of São Paulo is in the same range of some countries.

Topics: Adult; Aged; Brazil; Cholesterol; Chromatography, Gas; Cross-Sectional Studies; Edible Grain; Fabaceae; Feeding Behavior; Female; Fruit; Humans; Male; Middle Aged; Nutrition Assessment; Phytosterols; Plant Oils; Plants, Edible; Seeds; Sitosterols; Stigmasterol; Surveys and Questionnaires; Vegetables; Young Adult

The aim of this study was to evaluate the relationship between cholesterol metabolism and coronary plaque vulnerability.. Cholesterol homeostasis, defined as the balance between absorption and synthesis, influences the progression of coronary atherosclerosis.. Consecutive stable angina pectoris patients (N = 80) not receiving any lipid-lowering therapy were divided into 2 groups based on the presence of in vivo thin cap fibroatheroma (TCFA) in de novo target vessels assessed by the combined use of virtual histology intravascular ultrasound and optical coherence tomography.. Patients with in vivo TCFA (n = 42) showed a higher campesterol-to-lathosterol ratio (3.36 [interquartile range, 2.10 to 4.26] vs. 1.50 [1.20 to 2.50], p < 0.0001). The campesterol-to-lathosterol ratio, low-density lipoprotein (LDL) cholesterol, and high-sensitivity C-reactive protein (hsCRP) were positively correlated with the percentage of necrotic core volume (r = 0.520, p < 0.0001; r = 0.520, p < 0.0001; and r = 0.539, p < 0.0001, respectively) and negatively correlated with thinnest fibrous cap thickness (r = -0.566, p < 0.0001; r = -0.530, p < 0.0001; and r = -0.358, p = 0.007, respectively) . The independent predictors of the incidence of TCFA were the campesterol-to-lathosterol ratio (odds ratio: 3.989, 95% confidence interval: 1.688 to 9.428; p = 0.002), LDL cholesterol (odds ratio: 1.425, 95% confidence interval: 1.023 to 1.985; p = 0.03), hsCRP (odds ratio: 1.025, 95% confidence interval: 1.003 to 1.047; p = 0.02), and the percentage of necrotic core volume (odds ratio:1.084, 95% confidence interval: 1.012 to 1.161; p = 0.02).. Enhanced absorption and reduced synthesis of cholesterol may be related to coronary plaque vulnerability.

Topics: Aged; Angina, Stable; Biomarkers; C-Reactive Protein; Chi-Square Distribution; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Coronary Artery Disease; Coronary Vessels; Disease Progression; Female; Fibrosis; Humans; Linear Models; Logistic Models; Male; Middle Aged; Multivariate Analysis; Necrosis; Odds Ratio; Phytosterols; Plaque, Atherosclerotic; Predictive Value of Tests; Prognosis; Risk Factors; Rupture, Spontaneous; Tomography, Optical Coherence; Ultrasonography, Interventional

Previous methods for the quantitative analysis of phytosterols have usually used GC-MS and require elaborate sample preparation including chemical derivatization. Other common methods such as HPLC with absorbance detection do not provide information regarding the identity of the analytes. To address the need for an assay that utilizes mass selectivity while avoiding derivatization, a quantitative method based on LC-tandem mass spectrometry (LC-MS-MS) was developed and validated for the measurement of six abundant dietary phytosterols and structurally related triterpene alcohols including brassicasterol, campesterol, cycloartenol, β-sitosterol, stigmasterol, and lupeol in edible oils. Samples were saponified, extracted with hexane and then analyzed using reversed phase HPLC with positive ion atmospheric pressure chemical ionization tandem mass spectrometry and selected reaction monitoring. The utility of the LC-MS-MS method was demonstrated by analyzing 14 edible oils. All six compounds were present in at least some of the edible oils. The most abundant phytosterol in all samples was β-sitosterol, which was highest in corn oil at 4.35 ± 0.03 mg/g, followed by campesterol in canola oil at 1.84 ± 0.01 mg/g. The new LC-MS-MS method for the quantitative analysis of phytosterols provides a combination of speed, selectivity and sensitivity that exceed those of previous assays.

Topics: Cholestadienols; Cholesterol; Chromatography, Liquid; Molecular Structure; Pentacyclic Triterpenes; Phytosterols; Plant Oils; Reproducibility of Results; Sitosterols; Stigmasterol; Tandem Mass Spectrometry; Triterpenes

The reaction catalyzed by squalene synthase (EC.2.5.1.21) that converts two molecules of farnesyl pyrophosphate to squalene represents a crucial branch point of the isoprenoid pathway in diverting carbon flux towards the biosynthesis of sterols. In the present study two soybean squalene synthase genes, GmSQS1 and GmSQS2, were identified in the soybean genome and functionally characterized for their roles in sterol biosynthesis. Both genes encode a deduced protein of 413 amino acids. Complementation assays showed that the two genes were able to convert yeast sterol auxotrophy erg9 mutant to sterol prototrophy. Expression of GmSQS1 and GmSQS2 was ubiquitous in roots, stem, leaves, flower and young seeds of soybean, however GmSQS1 transcript was preferential in roots while GmSQS2 transcript was more in leaves. Their expression was lower in response to dehydration treatments suggesting they might be negative regulators of water stress adaptation. Transgenic Arabidopsis plants overexpressing GmSQS1 driven by either constitutive or seed-specific promoters showed increases in the major end product sterols: campesterol, sitosterol and stigmasterol, which resulted in up to 50% increase in total sterol content in the seeds. The increase in the end product sterols by GmSQS1 overexpression was at the level achievable by previously reported overexpression of individual or combination of other key enzymes in the sterol pathway. Together the data demonstrate that soybean SQS genes play an important role in diverting carbon flux to the biosynthesis of the end product sterols in the seeds.

Topics: Adaptation, Physiological; Amino Acid Sequence; Carbon; Cholesterol; Droughts; Farnesyl-Diphosphate Farnesyltransferase; Gene Expression Regulation, Plant; Genes, Plant; Glycine max; Molecular Sequence Data; Mutation; Phytosterols; Plant Leaves; Plant Proteins; Polyisoprenyl Phosphates; Promoter Regions, Genetic; Seeds; Sesquiterpenes; Sitosterols; Squalene; Stigmasterol; Stress, Physiological; Water

The cytotoxic effects of the oxidised derivatives of the phytosterols, stigmasterol and β-sitosterol, have previously been shown to be similar but less potent than those of the equivalent cholesterol oxides in the U937 cell line. The objective of the present study was to compare the cytotoxic effects of the oxidised derivatives of synthetic mixtures of campesterol and dihydrobrassicasterol in both the U937 and HepG2 cell lines. The parent compounds consisted of a campesterol: dihydrobrassicasterol mix at a ratio of 2:1 (2CMP:1DHB) and a dihydrobrassicasterol:campesterol mix at a ratio of 3:1 (3DHB:1CMP). The 2CMP:1DBH oxides were more cytotoxic in the U937 cells than the 3DBH:1CMP oxides but the difference in cytotoxicity was less marked in the HepG2 cells. The order of toxicity of the individual oxidation products was found to be similar to that previously observed for cholesterol, β-sitosterol and stigmasterol oxidation products in the U937 cell line. There was an increase in apoptotic nuclei in U937 cells incubated with the 7-keto and 7β-OH derivatives of both 2CMP:1DHB and 3DHB:1CMP and also in the presence of 3DHB:1CMP-3β,5α,6β-triol and 2CMP:1DHB-5β,6β-epoxide. An additional oxidation product synthesised from 2CMP:1DHB, 5,6,22,23-diepoxycampestane, was cytotoxic but did not induce apoptosis. These results signify the importance of campesterol oxides in the overall paradigm of phytosterol oxide cytotoxicity.

Topics: Apoptosis; Cell Survival; Chemistry Techniques, Synthetic; Cholesterol; Cytotoxins; Hep G2 Cells; Humans; Oxidation-Reduction; Phytosterols; U937 Cells

The validation of the use of plasma plant sterols as a marker of cholesterol absorption is frail. Nevertheless, plant sterol concentrations are routinely used to describe treatment-induced changes in cholesterol absorption. Their use has also been advocated as a clinical tool to tailor cholesterol-lowering therapy. Prior to wider implementation, however, the validity of plant sterols as absorption markers needs solid evaluation. Therefore, we compared plasma plant sterol concentrations to gold-standard stable isotope-determined cholesterol absorption. Plasma campesterol/TC concentrations (camp/TC) were measured in a population of 175 mildly hypercholesterolemic individuals (age: 59.7 ± 5.6 years; BMI: 25.5 ± 2.9 kg/m(2); LDL-C: 4.01 ± 0.56 mmol/l). We compared cholesterol absorption according to the plasma dual-isotope method in subjects with the highest camp/TC concentrations (N = 41, camp/TC: 2.14 ± 0.68 μg/mg) and the lowest camp/TC concentrations (N = 39, camp/TC: 0.97 ± 0.22 μg/mg). Fractional cholesterol absorption did not differ between the groups (24 ± 12% versus 25 ± 16%, P = 0.60), nor was it associated with plasma camp/TC concentrations in the total population of 80 individuals (β = 0.13; P = 0.30, adjusted for BMI and plasma triglycerides). Our findings do not support a relation between plasma plant sterol concentrations and true cholesterol absorption and, therefore, do not favor the use of these sterols as markers of cholesterol absorption. This bears direct consequences for the interpretation of earlier studies, as well as for future studies targeting intestinal regulation of cholesterol metabolism.

Topics: Cholesterol; Cross-Sectional Studies; Female; Humans; Intestinal Absorption; Male; Middle Aged; Phytosterols; Triglycerides

Obesity is associated with increased systemic and airway oxidative stress, which may result from a combination of adipokine imbalance and antioxidant defenses reduction. Obesity-mediated oxidative stress plays an important role in the pathogenesis of dyslipidemia, vascular disease, and nonalcoholic hepatic steatosis. The antidyslipidemic activity of pigeon pea were evaluated by high-fat diet (HFD) hamsters model, in which the level of high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), total cholesterol (TC), and total triglyceride (TG) were examined. We found that pigeon pea administration promoted cholesterol converting to bile acid in HFD-induced hamsters, thereby exerting hypolipidemic activity. In the statistical results, pigeon pea significantly increased hepatic carnitine palmitoyltransferase-1 (CPT-1), LDL receptor, and cholesterol 7α-hydroxylase (also known as cytochrome P450 7A1, CYP7A1) expression to attenuate dyslipidemia in HFD-fed hamsters; and markedly elevated antioxidant enzymes in the liver of HFD-induced hamsters, further alleviating lipid peroxidation. These effects may attribute to pigeon pea contained large of unsaturated fatty acids (UFA; C18:2) and phytosterol (β-sitosterol, campesterol, and stigmasterol). Moreover, the effects of pigeon pea on dyslipidemia were greater than β-sitosterol administration (4%), suggesting that phytosterone in pigeon pea could prevent metabolic syndrome.

Topics: Animals; Antioxidants; Cajanus; Carnitine O-Palmitoyltransferase; Cholesterol; Cholesterol 7-alpha-Hydroxylase; Cholesterol, HDL; Cholesterol, LDL; Chromatography, High Pressure Liquid; Cricetinae; Diet, High-Fat; Disease Models, Animal; Hypercholesterolemia; Lipid Peroxidation; Liver; Male; Obesity; Oxidative Stress; Phytosterols; Receptors, LDL; Sitosterols; Stigmasterol; Triglycerides

We investigated the behaviour of non-cholesterol sterols, surrogate markers of cholesterol absorption (campesterol and sitosterol) and synthesis (lathosterol), in primary hyperlipemias.. We studied 53 patients with polygenic hypercholesterolemia (PH), 38 patients with familial combined hyperlipemia (FCH), and 19 age- and sex-matched healthy control subjects. In all participants, plasma sitosterol, campesterol and lathosterol were determined by gas chromatography coupled to mass spectrometry. To correct for the effect of plasma lipid levels, non-cholesterol sterol concentrations were adjusted for plasma cholesterol (10² μmol/mmol cholesterol). Patients with FCH were more frequently men, and had higher body mass index (BMI), fasting glucose, insulin and HOMA-IR. Lathosterol was higher in FCH than in pH or controls (p < 0.05). Campesterol was significantly lower in FCH (p < 0.05), while no differences were found between pH and controls. Sitosterol displayed higher values in pH compared to FCH (p < 0.001) and controls (p < 0.05). Spearman's rank correlations showed positive correlations of lathosterol with BMI, waist circumference, HOMA-IR, triglycerides, apoprotein B, and a negative one with HDL-cholesterol. Sitosterol had a negative correlation with BMI, waist circumference, HOMA-IR, triglycerides, and a positive one with HDL-cholesterol and apoprotein AI. Multivariate regression analyses showed that cholesterol absorption markers predicted higher HDL-cholesterol levels, while HOMA-IR was a negative predictor of sitosterol and BMI a positive predictor of lathosterol.. Our findings suggest the occurrence of an increased cholesterol synthesis in FCH, and an increased cholesterol absorption in pH. Markers of cholesterol synthesis cluster with clinical and laboratory markers of obesity and insulin resistance.

Topics: Adult; Aged; Biomarkers; Case-Control Studies; Cholesterol; Female; Gas Chromatography-Mass Spectrometry; Humans; Hypercholesterolemia; Hyperlipidemia, Familial Combined; Intestinal Absorption; Italy; Linear Models; Male; Middle Aged; Multifactorial Inheritance; Multivariate Analysis; Phytosterols; Risk Assessment; Risk Factors; Sitosterols; Sterols; Young Adult

We examined the associations between extracerebral markers of cholesterol homeostasis and cognitive decline over 6 years of follow-up, and studied the modifying effect of apolipoprotein E (ApoE) e4. Data were collected in the Longitudinal Aging Study Amsterdam (n = 967, with longitudinal data on cognition, ages ≥ 65 years) and analyzed using linear mixed models. General cognition (Mini-Mental State Examination; MMSE), memory (Auditory Verbal Learning Test), and information processing speed (Coding task) were measured. The results show that ApoE e4 was a significant effect modifier. Significant associations were found only in ApoE e4 noncarriers (n = 718). We found a nonlinear negative association between the ratio of lanosterol to cholesterol (≤ 189.96 ng/mg), a marker for cholesterol synthesis, and general cognition. Lower cholesterol absorption, i.e., lower ratios of campesterol and sitosterol to cholesterol, as well as a higher rate of cholesterol synthesis relative to absorption were associated with lower information processing speed. In ApoE e4 carriers, the negative association between the ratio of campesterol to cholesterol and memory reached borderline significance. Future research should focus on the interaction between (disturbed) cholesterol homeostasis and ApoE e4 status with respect to dementia.

Topics: Aged; Aged, 80 and over; Apolipoprotein E4; Brain Chemistry; Cholesterol; Cognition Disorders; Down-Regulation; Female; Follow-Up Studies; Genetic Carrier Screening; Homeostasis; Humans; Longitudinal Studies; Male; Middle Aged; Phytosterols

Quantification of plasma noncholesterol sterols allows the study of cholesterol absorption and synthesis. A pattern of low cholesterol absorption and high synthesis has been demonstrated in patients with obesity and insulin resistance. To understand the relationship between cholesterol absorption/synthesis and visceral obesity, we investigated surrogate markers of cholesterol absorption (campesterol and sitosterol) and synthesis (lathosterol) in dyslipidaemic patients with different representation of abdominal fat, estimated by ultrasonographic measurement of visceral fat area (VFA).. In 126 patients with primary hyperlipaemias, plasma sitosterol, campesterol and lathosterol were determined by gas chromatography coupled with mass spectrometry. Visceral and subcutaneous fats were evaluated by ultrasonography. The study population was divided into two groups on the basis of VFA median values, below/equal and above 154 cm(2) . RESULTS Patients with higher VFA had significantly higher lathosterol levels (median 109 vs. 76 × 10(2) μmol/mmol cholesterol P < 0·004), body mass index, waist circumference, blood pressure, triglycerides, insulin, homoeostatic model assessment (HOMA)-IR and lower high-density lipoprotein (HDL)-C. VFA was positively correlated with lathosterol (ρ = 0·35, P < 0·001) and negatively with HDL-C (ρ = -0·43, P < 0·001), campesterol (ρ = -0·23, P = 0.01) and sitosterol (ρ = -0·35, P < 0·001). VFA was an independent predictor of lathosterol values (β = 0·389, P < 0·0001, P of the model < 0·0001);age, systolic blood pressure, BMI, waist circumference, triglycerides, HDL-C and HOMA failed to enter the final equation..   In hyperlipidaemic patients, the amount of visceral fat correlates with cholesterol synthesis; the use of ultrasonographic detection of abdominal adiposity allows a better characterization of cholesterol pathway, potentially useful for a tailored therapeutic approach.

Topics: Adult; Body Fat Distribution; Body Mass Index; Cholesterol; Chromatography, Gas; Dyslipidemias; Female; Humans; Intra-Abdominal Fat; Male; Mass Spectrometry; Middle Aged; Phytosterols; Sitosterols; Statistics as Topic; Ultrasonography; Waist Circumference

A simple method for the determination of cellular uptake of phytosterols by Caco-2 cells has been developed by ultra performance liquid chromatography with ultraviolet detection (UPLC-UV). UPLC-UV was established using an ODS column, acetonitrile/H(2)O (9:1, v/v) as a mobile phase, and a detection wavelength at 210 nm. As analytes, β-sitosterol, campesterol, stigmasterol, and brassicasterol were selected based on the abundance in foods and the similarity of their structures. A linear relation was observed between the peak area and the amount of sterol injected from 50 to 2000 pmol (r>0.999) with a relative standard deviation (RSD) of less than 2.5% (n=6). This method was applied to the determination of cellular uptake of phytosterols by Caco-2 cells. Recovery tests showed that phytosterols were extracted from the cell lysates by chloroform and determined by UPLC-UV with a recovery rate of more than 80.2% and an RSD of less than 11.3% (n=3). When Caco-2 cells were incubated with phytosterols at 37°C, their uptake was increased with time in a concentration-dependent manner. This method will be useful for the simultaneous determination of cellular phytosterols in an in vitro intestine model.

Topics: Biological Transport, Active; Caco-2 Cells; Cholestadienols; Cholesterol; Chromatography, Liquid; Humans; Kinetics; Phytosterols; Sitosterols; Stigmasterol

Euterpe Oleracea (açai) is a fruit from the Amazon region whose chemical composition may be beneficial for individuals with atherosclerosis. We hypothesized that consumption of Euterpe Oleracea would reduce atherosclerosis development by decreasing cholesterol absorption and synthesis.. Male New Zealand rabbits were fed a cholesterol-enriched diet (0.5%) for 12 weeks, when they were randomized to receive Euterpe Oleracea extract (n = 15) or water (n = 12) plus a 0.05% cholesterol-enriched diet for an additional 12 weeks. Plasma phytosterols and desmosterol were determined by ultra-performance liquid chromatography and mass spectrometry. Atherosclerotic lesions were estimated by computerized planimetry and histomorphometry.. At sacrifice, animals treated with Euterpe Oleracea had lower levels of total cholesterol (p =0.03), non-HDL-cholesterol (p = 0.03) and triglycerides (p = 0.02) than controls. These animals had smaller atherosclerotic plaque area in their aortas (p = 0.001) and a smaller intima/media ratio (p = 0.002) than controls, without differences in plaque composition. At the end of the study, campesterol, β-sitosterol, and desmosterol plasma levels did not differ between groups; however, animals treated with Euterpe Oleracea showed lower desmosterol/campesterol (p = 0.026) and desmosterol/ β-sitosterol (p =0.006) ratios than controls.. Consumption of Euterpe Oleracea extract markedly improved the lipid profile and attenuated atherosclerosis. These effects were related in part to a better balance in the synthesis and absorption of sterols.

Topics: Animals; Arecaceae; Atherosclerosis; Cholesterol; Cholesterol, Dietary; Chromatography, High Pressure Liquid; Desmosterol; Immunoenzyme Techniques; Lipids; Male; Phytosterols; Phytotherapy; Plant Extracts; Rabbits; Sitosterols; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

We prospectively evaluated incidence of prolonged (>28 days) parenteral nutrition (PN), associated complications, and significance of parenteral plant sterols (PS) in neonatal intestinal failure-associated liver disease (IFALD) compared with children.. We recruited 28 neonates (mean age 50 days, range 28-126) and 11 children (6.9 y, 2.1-16.6) in all of Finland. Patients underwent repeated measurements of serum cholesterol, noncholesterol sterols, including PS, cholestanol and cholesterol precursors, and liver biochemistry during and 1 month after discontinuation of PN. Healthy matched neonates (n=10) and children (n=22) served as controls.. IFALD occurred more frequently among neonates (63%) than children (27%; P<0.05). Ratios of serum PS, including stigmasterol, sitosterol, avenasterol, and campesterol, and total PS were increased among neonates compared with healthy controls and children on PN by 2- to 22- and 2- to 5-fold (P<0.005), respectively. Neonates with IFALD had significantly higher ratios of serum PS and cholestanol compared with neonates without IFALD (P<0.05). Total duration of PN associated with serum cholestanol, stigmasterol, avenasterol, alanine aminotransferase, and aspartate aminotransferase (r=0.472-0.636, P<0.05). Cholestanol and individual serum PS, excluding campesterol, reflected direct bilirubin (r=0.529-0.688, P<0.05). IFALD persisted after discontinuation of PN in 25% of neonates with 4.2- and 2.2-times higher ratios of serum stigmasterol and cholestanol compared with neonates without IFALD (P<0.05).. Frequent occurrence of IFALD among neonates on PN displays an association to duration of PN and markedly increased serum PS, especially stigmasterol, in comparison to healthy neonates and children on PN. Striking accumulation of parenteral PS may contribute to IFALD among neonates.

Topics: Adolescent; Age Factors; Alanine Transaminase; Aspartate Aminotransferases; Bilirubin; Child; Child, Preschool; Cholestanol; Cholesterol; Dietary Fats; Fat Emulsions, Intravenous; Female; Finland; Humans; Infant; Infant, Newborn; Intestinal Diseases; Liver Diseases; Male; Olive Oil; Parenteral Nutrition; Phytosterols; Plant Oils; Prevalence; Prospective Studies; Soybean Oil; Stigmasterol

Plant sterols such as sitosterol and campesterol are frequently administered as cholesterol-lowering supplements in food. Recently, it has been shown in mice that, in contrast to the structurally related cholesterol, circulating plant sterols can enter the brain. We questioned whether the accumulation of plant sterols in murine brain is reversible. After being fed a plant sterol ester-enriched diet for 6 weeks, C57BL/6NCrl mice displayed significantly increased concentrations of plant sterols in serum, liver, and brain by 2- to 3-fold. Blocking intestinal sterol uptake for the next 6 months while feeding the mice with a plant stanol ester-enriched diet resulted in strongly decreased plant sterol levels in serum and liver, without affecting brain plant sterol levels. Relative to plasma concentrations, brain levels of campesterol were higher than sitosterol, suggesting that campesterol traverses the blood-brain barrier more efficiently. In vitro experiments with brain endothelial cell cultures showed that campesterol crossed the blood-brain barrier more efficiently than sitosterol. We conclude that, over a 6-month period, plant sterol accumulation in murine brain is virtually irreversible.

Topics: Animals; Astrocytoma; Blood-Brain Barrier; Brain; Cell Line, Tumor; Cholesterol; Diet; Dose-Response Relationship, Drug; Endothelial Cells; Humans; Liver; Male; Membrane Microdomains; Mice; Mice, Inbred C57BL; Phytosterols; Sitosterols; Stigmasterol; Time Factors

Evening Primrose oil is a natural product extracted by cold-pressed from Oenothera biennis L. seeds. The unsaponifiable matter of this oil is an important source of interesting minor compounds, like long-chain fatty alcohols, sterols and tocopherols. In the present study, sterols were isolated from the unsaponifiable matter of Evening Primrose oil, and the composition was identified and quantified by GC and GC-MS. The major components of sterols fraction were β-Sitosterol and campesterol. We investigated the ability of sterols from Evening Primrose oil to inhibit the release of different proinflammatory mediators in vitro by murine peritoneal macrophages stimulated with lipopolysaccharide. Sterols significantly and dose-dependently decreased nitric oxide production. Western blot analysis showed that nitric oxide reduction was a consequence of the inhibition of inducible nitric oxide synthetase expression. Sterols also reduced tumor necrosis factor-α, interleukine 1β and tromboxane B₂. However, sterols did not reduce prostaglandin E₂. The reduction of eicosanoid release was related to the inhibition of cyclooxygenase-2 expression. These results showed that sterols may have a protective effect on some mediators involved in inflammatory damage development, suggesting its potential value as a putative functional component of Evening Primrose oil.

Topics: Animals; Cholesterol; Cyclooxygenase 2 Inhibitors; Dose-Response Relationship, Drug; Inflammation; Inflammation Mediators; Lipopolysaccharides; Macrophages; Mice; Nitric Oxide; Nitric Oxide Synthase Type II; Oenothera biennis; Phytosterols; Phytotherapy; Plant Oils; Seeds; Sitosterols

We investigated how liver fat content (LFC) influences cholesterol metabolism by quantifying liver fat using proton magnetic resonance spectroscopy and by measuring the serum concentrations of lathosterol, a marker of cholesterol synthesis, and sitosterol and campesterol, two markers of cholesterol absorption. We also evaluated whether this relationship could be modified by statin therapy. The study was conducted in 263 patients with type 2 diabetes, 137 of whom (52.0%) received statin therapy.. One hundred and sixty-five patients (62.7%) had steatosis (LFC>5.5%). We performed specific analyses in patients without statin therapy and in patients treated with statin therapy. In both groups, the lathosterol to cholesterol ratio correlated positively with LFC, and in multivariate analysis, the lathosterol to cholesterol ratio was associated with LFC independently of age, gender and BMI. Sitosterol and campesterol concentrations were not associated with LFC.. Our study suggests that in patients with type 2 diabetes, LFC is associated with an increase in cholesterol synthesis that is independent of obesity or diabetes mellitus. Statin therapy does not modify this relationship.

Topics: Aged; Biomarkers; Cholesterol; Diabetes Mellitus, Type 2; Dyslipidemias; Fatty Liver; Female; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Linear Models; Liver; Magnetic Resonance Spectroscopy; Male; Middle Aged; Multivariate Analysis; Non-alcoholic Fatty Liver Disease; Phytosterols; Risk Factors; Sitosterols; Treatment Outcome

Triterpenoid compounds found in free and ester forms in extracts of entire fruits and leaves and in fruit and leaf cuticular waxes of bilberry (Vaccinium myrtillus L.) collected in Finland and Poland were identified and quantitated by gas chromatography-mass spectrometry coupled to a flame ionization detector (GC-MS/FID). The main bilberry triterpenoid profile consisted of α- and β-amyrin, α- and β-amyrenone, campesterol, cholesterol, citrostadienol (in berries), cycloartanol, erythrodiol, lupeol, 24-methylenecycloartanol, sitosterol, sitostanol, stigmasterol, stigmasta-3,5-dien-7-one, uvaol, oleanolic and ursolic aldehydes, and oleanolic, ursolic, 2α-hydroxyoleanolic, and 2α-hydroxyursolic acids. Friedelin and D:A-friedooleanan-3β-ol were found only in Finnish plants, whereas D:C-friedours-7-en-3β-ol and taraxasterol were found only in Polish plants. To our knowledge, this is the first thorough description of triterpenoid compounds in this species. The presented results revealed that the triterpenoid profile of bilberry varied considerably between different organs of the plant, regardless of the plant origin, as well as between plant samples obtained from the two geographical locations.

Topics: Anthocyanins; Cholesterol; Finland; Fruit; Gas Chromatography-Mass Spectrometry; Molecular Structure; Oleanolic Acid; Phytosterols; Plant Extracts; Plant Leaves; Poland; Sitosterols; Triterpenes; Vaccinium myrtillus

Phytosterol supplements lower low-density lipoprotein (LDL) cholesterol, but accumulate in vascular lesions of patients and limit the anti-atherosclerotic effects of LDL lowering in apolipoprotein E (Apo E)-deficient mice, suggesting that the cholesterol-lowering benefit of phytosterol supplementation may not be fully realized. Individual phytosterols have cell-type specific effects that may be either beneficial or deleterious with respect to atherosclerosis, but little is known concerning their effects on macrophage function. The effects of phytosterols on ABCA1 and ABCG1 abundance, cholesterol efflux and inflammatory cytokine secretion were determined in cultured macrophage foam cells. Among the commonly consumed phytosterols, stigmasterol increased expression of ABCA1 and ABCG1 and increased efflux of cholesterol to apolipoprotein (Apo) AI and high-density lipoprotein (HDL). Campesterol and sitosterol had no effect on ABCA1 or ABCG1 levels. Sitosterol had no effect on cholesterol efflux to Apo AI or HDL, whereas campesterol had a modest but significant reduction in cholesterol efflux to HDL in THP-1 macrophages. Whereas stigmasterol blunted aggregated LDL (agLDL) induced increases in tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-1β secretion, sitosterol exacerbated these effects. The presence of campesterol had no effect on agLDL-induced inflammatory cytokine secretion from THP-1 macrophages. In conclusion, the presence of stigmasterol in modified lipoproteins promoted cholesterol efflux and suppressed inflammatory cytokine secretion in response to lipid loading in macrophage foam cells. While campesterol was largely inert, the presence of sitosterol increased the proinflammatory cytokine secretion.

Topics: Animals; Apolipoprotein A-I; ATP Binding Cassette Transporter 1; ATP Binding Cassette Transporter, Subfamily G, Member 1; ATP-Binding Cassette Transporters; Cells, Cultured; Cholesterol; Foam Cells; Humans; Interleukin-1beta; Interleukin-6; Interleukin-8; Lipoproteins; Lipoproteins, HDL; Lipoproteins, LDL; Male; Mice; Mice, Inbred C57BL; Phytosterols; Sitosterols; Stigmasterol; Tumor Necrosis Factor-alpha

Phytosterolemia is an inherited disorder characterized by hypercholesterolemia and premature atherosclerosis, together with increased inflammatory states in some cases. The underlying mechanisms of atherogenesis in phytosterolemia, however, have not been completely elucidated. In this study, we investigated whether phytosterols would affect inflammatory reactions in macrophages and macrophage cell lines.. We incubated RAW264.7 cells (RAW) and mouse peritoneal macrophages (MPMs) with sitosterol (Sito), campesterol (Camp) or cholesterol (Chol) at low (8 µM, 16 µM) or high (160 µM) concentrations, and investigated their effects on LPS-induced secretion of IL-6 and TNF-α. We also analyzed their effects on endoplasmic reticulum (ER) stress in both cells, and on the cell proliferation of RAW.. At low sterol concentrations, only Chol resulted in a tendency toward the increased secretion of TNF-α from MPMs. At high concentrations, Chol induced a significant increase in TNF-α secretions from both cells; however, Sito resulted in a non-significant increase in TNF-α secretion. The effects on IL-6 secretions of Sito were also significantly less than those of Chol. Camp increased the secretions of both cytokines from MPMs; however, the extent of these increases was less pronounced than that of Chol. Augmentation of ER stress was greatest with Chol among the sterols, and the proliferation of RAW cells was inhibited only with Chol.. The lesser degree of inflammatory reactions and toxicity in macrophages with phytosterols than with cholesterol suggests that plant sterols themselves might not be primarily responsible for atherogenesis in phytosterolemia.

Topics: Alternative Splicing; Animals; Cell Proliferation; Cells, Cultured; Cholesterol; DNA-Binding Proteins; Endoplasmic Reticulum; Hypercholesterolemia; Interleukin-6; Intestinal Diseases; Lipid Metabolism, Inborn Errors; Lipopolysaccharides; Macrophage Activation; Macrophages; Mice; Phytosterols; Regulatory Factor X Transcription Factors; Transcription Factors; Tumor Necrosis Factor-alpha

There is a significant flux of the neurotoxic oxysterol 27-hydroxycholesterol (27OHC) from the circulation across the blood-brain barrier. Because there is a correlation between 27OHC and cholesterol in the circulation and lipoprotein-bound cholesterol does not pass the blood-brain barrier, we have suggested that 27OHC may mediate the effects of hypercholesterolemia on the brain. We previously demonstrated a modest accumulation of 27OHC in brains of patients with sporadic Alzheimer's disease (AD), consistent with a role of 27OHC as a primary pathogenetic factor. We show here that there is a 4-fold accumulation of 27OHC in different regions of the cortexes of patients carrying the Swedish amyloid precursor protein (APPswe) 670/671 mutation. The brain levels of sitosterol and campesterol were not significantly different in the AD patients compared with the controls, suggesting that the blood-brain barrier was intact in the AD patients. We conclude that accumulation of 27OHC is likely to be secondary to neurodegeneration, possibly a result of reduced activity of CYP7B1, the neuronal enzyme responsible for metabolism of 27OHC. We discuss the possibility of a vicious circle in the brains of the patients with familial AD whereby neurodegenerative changes cause an accumulation of 27OHC that further accelerates neurodegeneration.

Topics: Aged; Alzheimer Disease; Amyloid beta-Protein Precursor; Blotting, Western; Brain; Cholesterol; Female; Humans; Hydroxycholesterols; Male; Middle Aged; Mutation; Phytosterols; Sitosterols

Glycerolipids, sphingolipids, and sterol lipids constitute the major lipid classes in plants. Sterol lipids are composed of free and conjugated sterols, i.e., sterol esters, sterol glycosides, and acylated sterol glycosides. Sterol lipids play crucial roles during adaption to abiotic stresses and plant-pathogen interactions. Presently, no comprehensive method for sterol lipid quantification in plants is available. We used nanospray ionization quadrupole-time-of-flight mass spectrometry (Q-TOF MS) to resolve and identify the molecular species of all four sterol lipid classes from Arabidopsis thaliana. Free sterols were derivatized with chlorobetainyl chloride. Sterol esters, sterol glycosides, and acylated sterol glycosides were ionized as ammonium adducts. Quantification of molecular species was achieved in the positive mode after fragmentation in the presence of internal standards. The amounts of sterol lipids quantified by Q-TOF MS/MS were validated by comparison with results obtained with TLC/GC. Quantification of sterol lipids from leaves and roots of phosphate-deprived A. thaliana plants revealed changes in the amounts and molecular species composition. The Q-TOF method is far more sensitive than GC or HPLC. Therefore, Q-TOF MS/MS provides a comprehensive strategy for sterol lipid quantification that can be adapted to other tandem mass spectrometers.

Topics: Arabidopsis; Cholesterol; Chromatography, Gas; Chromatography, Thin Layer; Lipids; Mass Spectrometry; Phytosterols; Plants; Sitosterols; Sterols; Stigmasterol

Plant sterols such as sitosterol and campesterol are frequently applied as functional food in the prevention of atherosclerosis. Recently, it became clear that plasma derived plant sterols accumulate in murine brains. We questioned whether plant sterols in the brain are associated with alterations in brain cholesterol homeostasis and subsequently with brain functions. ATP binding cassette (Abc)g5-/- mice, a phytosterolemia model, were compared to Abcg5+/+ mice for serum and brain plant sterol accumulation and behavioral and cognitive performance. Serum and brain plant sterol concentrations were respectively 35-70-fold and 5-12-fold increased in Abcg5-/- mice (P<0.001). Plant sterol accumulation resulted in decreased levels of desmosterol (P<0.01) and 24(S)-hydroxycholesterol (P<0.01) in the hippocampus, the brain region important for learning and memory functions, and increased lanosterol levels (P<0.01) in the cortex. However, Abcg5-/- and Abcg5+/+ displayed no differences in memory functions or in anxiety and mood related behavior. The swimming speed of the Abcg5-/- mice was slightly higher compared to Abcg5+/+ mice (P<0.001). In conclusion, plant sterols in the brains of Abcg5-/- mice did have consequences for brain cholesterol metabolism, but did not lead to an overt phenotype of memory or anxiety related behavior. Thus, our data provide no contra-indication for nutritional intake of plant sterol enriched nutrition.

Topics: Affect; Animals; Anxiety Disorders; Atherosclerosis; ATP-Binding Cassette Transporters; Behavior, Animal; Brain; Cholesterol; Desmosterol; Diet; Hippocampus; Homeostasis; Hydroxycholesterols; Hypercholesterolemia; Intestinal Diseases; Lanosterol; Lipid Metabolism, Inborn Errors; Male; Maze Learning; Memory; Mice; Mice, Mutant Strains; Phytosterols; Sitosterols; Stigmasterol

Primary hypobetalipoproteinemia (pHBL) is characterized by plasma cholesterol levels <5th percentile of a population distribution. Plasma non-cholesterol sterols (NCS) are markers of cholesterol liver synthesis and intestinal absorption. Plasma NCS were measured in 111 pHBL subjects, 108 low cholesterol (LC) and 253 normal cholesterol (NC) controls to gain information on cholesterol metabolism in pHBL, and to assess whether NCS measurements may aid in distinguishing pHBL from LC controls. pHBL subjects compared with LC controls were characterized by increased cholesterol absorption (campesterol/TC) while the synthesis (lathosterol/TC) was not increased. The analysis of pHBL subjects divided by gene defect showed a high campesterol/TC ratio in familial HBL (FHBL) carriers of apolipoproteinB (ApoB) truncations longer than ApoB48 and in FHBL without known gene defect ("not linked"). One not linked kindred was characterized by an increase of the 7-dehydrocholesterol/latho ratio. In a discriminant analysis plasma NCS did not improve the power of TC levels to distinguish FHBL from LC controls. In conclusion, increased cholesterol absorption was found in FHBL subjects harbouring truncations of ApoB>ApoB48, and FHBL harbouring as yet unknown molecular defects. Not linked FHBL kindred are not homogeneous in terms of plasma NCS levels. NCS cannot replace genetic HBL analysis.

Topics: Absorption; Adolescent; Adult; Aged; Aged, 80 and over; Child; Cholesterol; Family Health; Humans; Hypobetalipoproteinemias; Intestinal Mucosa; Middle Aged; Models, Genetic; Mutation; Phenotype; Phytosterols; Sterols

Phytosterols are bioactive compounds which occur in low concentrations in plant oils. Due to their beneficial effects on human health, phytosterols have already been supplemented to food. Commercial phytosterol standards show insufficient purity and/or are very expensive. In this study, we developed a high-speed counter-current chromatography (HSCCC) method for the fractionation and analysis of a commercial crude β-sitosterol standard (purity ∼60% according to supplier). Different solvent systems were tested in shake-flask experiments, and the system n-hexane/methanol/aqueous silver nitrate solution (34/24/1, v/v/v) was finally used for HSCCC fractionation. About 50 mg phytosterols was injected and distributed into 57 fractions. Selected fractions were condensed and re-injected into the HSCCC system. This measure provided pure sitostanol (>99%) and β-sitosterol (∼99%), as well as a mixture of campesterol and stigmasterol without further phytosterols. An enriched HSCCC fraction facilitated the mass spectrometric analysis of further 11 minor phytosterols (after trimethylsilylation). It was also shown that the commercial product contained about 0.3% carotinoids which eluted without delay into an early HSCCC fraction and which were separated from the phytosterols.

Topics: Cholesterol; Countercurrent Distribution; Mass Spectrometry; Phytosterols; Sitosterols; Solvents; Stigmasterol

Plant sterols (PS) in parenteral nutrition (PN) may contribute to intestinal failure-associated liver disease. We investigated interrelations between serum PS, liver function and histology, cholesterol metabolism, and characteristics of PN.. Eleven patients with intestinal failure (mean age 6.3 years) receiving long-term PN were studied prospectively (mean 254 days) and underwent repeated measurements of serum lipids, noncholesterol sterols, including PS, and liver enzymes. PS contents of PN were analyzed. Liver biopsy was obtained in 8 patients. Twenty healthy children (mean age 5.7 years) served as controls.. Median percentage of parenteral energy of total daily energy (PN%) was 48%, including 0.9 g · kg(-1) · day(-1) of lipids. Respective amounts of PN sitosterol, campesterol, avenasterol, and stigmasterol were 683, 71, 57, and 45 μg · kg(-1) · day(-1). Median serum concentrations of sitosterol (48 vs 7.5 μmol/L, P < 0.001), avenasterol (2.9 vs 1.9, P < 0.01), stigmasterol (1.9 vs 1.2, P < 0.005), but not that of campesterol (9.8 vs 12, P = 0.22), were increased among patients in relation to controls, and correlated with PN% (r = 0.81-0.88, P < 0.005), but not with PN fat. Serum cholesterol precursors were higher in patients than in controls. Serum liver enzymes remained close to normal range. Glutamyl transferase correlated with serum PS (r = 0.61-0.62, P < 0.05). Liver fibrosis in 5 patients reflected increased serum PS (r = 0.55-0.60, P = 0.16-0.12).. Serum PS moderately increase during olive oil-based PN, and correlate positively with PN% and glutamyl transferase. Despite well-preserved liver function, histology often revealed significant liver damage.

Topics: Adolescent; Biomarkers; Case-Control Studies; Child; Child, Preschool; Cholestasis; Cholesterol; Female; Follow-Up Studies; Humans; Infant; Intestines; Lipid Metabolism; Lipids; Liver; Liver Failure; Male; Olive Oil; Parenteral Nutrition; Phytosterols; Plant Oils; Prospective Studies; Sitosterols

High dose daily intake of plant sterols decreases the uptake of cholesterol in the intestine by competitive mechanisms and thus leads to reduced serum levels of total and LDL-cholesterol. By this, the commercialization of plant sterol enriched 'functional food' products is rapidly increasing. Subjects using these kinds of diet present a duplication of their serum plant sterol levels after long-term intake. In analogy to cholesterol, plant sterols such as campesterol and sitosterol can be oxidized to oxyphytosterols and these may counteract the primary anti-atherosclerotic action of cholesterol lowering. In order to investigate the whole spectrum of the consequences following high plant sterol intake a highly sensitive and specific isotope dilution gas chromatography-mass spectrometry method for the analysis of 7-oxygenated campesterol/sitosterol in trace amounts in human serum is presented in this paper. The validation was based on limits for detection and quantification, recovery, precision and minimization of autoxidation during work-up. Our results show an overall coefficient of variation ≤10% for the precision. The lowest limits for detection and quantification for 7α-hydroxy-campesterol were 7 pg/mL and 23 pg/mL, respectively. Data for overall sum recovery ranged from 92% to 115%. We practically used this method for analysis of oxyphytosterols simultaneously with plant sterol concentrations in serum from healthy volunteers. Sixteen subjects were treated with plant sterol enriched margarine (3 g/day) for 28 days. The results showed a significant increase of the oxyphytosterol 7β-hydroxy-sitosterol from 1.19±0.54 (before intake) to 2.24±1.24 ng/mL (mean±SD; +86.7%; P=0.007) after intake of the margarine. There was a highly significant correlation between the serum levels of campesterol and the sum of 7-oxygenated campesterol (R(2)=0.915; P<0.001) and sitosterol and the sum of 7-oxygenated sitosterol (R(2)=0.915; P<0.001). We can conclude from this study that the analytic method is well suited for detection of OPS, even at trace amounts.

Topics: Adult; Blood Chemical Analysis; Cholesterol; Female; Gas Chromatography-Mass Spectrometry; Humans; Limit of Detection; Linear Models; Male; Margarine; Oxygen; Phytosterols; Sitosterols

Plant sterols are important multifunctional lipids, which are involved in determining membrane properties. Biophysical characteristics of model lipid and isolated animal membranes with altered sterol component have been intensively studied. In plants however, the precise mechanisms of involvement of sterols in membrane functioning remain unclear. In present work the possible interactions between sterols and other membrane lipids in plant cells were studied. A useful experimental approach for elucidating the roles of sterols in membrane activity is to use agents that specifically bind with endogenous sterols, for example the antibiotic nystatin. Membrane characteristics and the composition of membrane lipids in the roots of wheat (Triticum aestivum L.) seedlings treated with nystatin were analyzed. The application of nystatin greatly increased the permeability of the plasma membrane for ions and SH-containing molecules and decreased the total sterol level mainly as a consequence of a reduction in the amount of β-sitosterol and campesterol. Dynamic light-scattering was used to confirm the in vitro formation of stable complexes between nystatin and β-sitosterol or cholesterol. Sterol depletion was accompanied by a significant rise in total glycoceramide (GlCer) content after 2h treatment with nystatin. Analysis of the GlCer composition using mass spectrometry with electrospray ionization demonstrated that nystatin induced changes in the ratio of molecular species of GlCer. Our results suggest that changes in the sphingolipid composition can contribute to the changes in plasma membrane functioning induced by sterol depletion.

Topics: Biological Transport; Cell Membrane; Cell Membrane Permeability; Ceramides; Cholesterol; Ionophores; Membrane Lipids; Nystatin; Phytosterols; Plant Roots; Potassium; Sitosterols; Spectrometry, Mass, Electrospray Ionization; Sphingolipids; Time Factors; Triticum

The first phytochemical study of Simira eliezeriana Peixoto (Rubiaceae) allowed the isolation and structural determination of two new diterpenes named simirane A [(5R,6R,8R,9R,10S,11S,13S)-6β,11β-dihydroxy-2,4(18),15-erythroxylatrien-1-one] (1) and simirane B [(5S,8R,9R,10S,11S,13S)-11β-hydroxy-2,4(18),15-erythroxylatrien-1-one] (2), together with seven known compounds: sitosterol (3), stigmasterol (4), campesterol (5), coniferaldehyde (6), vanillin (7), pinoresinol (8) and harman (9) from the bark of the plant. The structures of the compounds were established on the basis of spectroscopic methods, including 1-D and 2-D NMR, HRESI-MS and CD analysis and comparisons with available literature data of known compounds.

Topics: Acrolein; Benzaldehydes; Cholesterol; Diterpenes; Ethanol; Furans; Harmine; Lignans; Magnetic Resonance Spectroscopy; Molecular Structure; Phytosterols; Plant Bark; Plant Extracts; Rubiaceae; Sitosterols

Bile acid (BA) synthesis is essential in cholesterol and lipid homoeostasis.. Serum samples from 435 normal and 23 cholecystectomized subjects were obtained after overnight fasting and assayed for markers of BA and cholesterol synthesis, as well as cholesterol absorption. We determined whether BA synthesis was related to fibroblast growth factor 19 (FGF19; a circulating metabolic regulator that is thought to inhibit BA synthesis), gender, age and serum lipids.. Bile acid synthesis varied more than 9-fold in normal individuals and was 29% higher in men than in women. Whilst low-density lipoprotein cholesterol increased with age, BA and cholesterol synthesis were stable. BA production was positively correlated with serum triglycerides (TGs), and 35% of individuals with a high level (>95th percentile) of BA synthesis had hypertriglyceridaemia (HTG) (>95th percentile). Serum FGF19 levels varied by 7-fold in normal individuals and were related inversely to BA synthesis but were not related to gender, plasma lipids or history of cholecystectomy.. Bile acid synthesis has a wide inter-individual variation, is lower in women than in men and is correlated positively with serum TGs. High BA production is frequently linked to HTG. Age-related hypercholesterolaemia is not associated with changes in BA or cholesterol production, nor to an increase in cholesterol absorption. In humans, the circulating level of FGF19 may regulate hepatic BA production under fasting conditions.

Topics: Adult; Aged; Aged, 80 and over; Bile; Bile Acids and Salts; Case-Control Studies; Cholelithiasis; Cholestenones; Cholesterol; Female; Fibroblast Growth Factors; Humans; Hypertriglyceridemia; Male; Middle Aged; Phytosterols; Sex Factors; Young Adult

Familial combined hyperlipidemia (FCH) is a common familial lipid disorder characterized by increases in plasma total cholesterol, triglyceride, and apolipoprotein B-100 levels. In light of prior metabolic and genetic research, our purpose was to ascertain whether FCH cases had significant abnormalities of plasma markers of cholesterol synthesis and absorption as compared to unaffected kindred members.. Plasma levels of squalene, desmosterol, and lathosterol (cholesterol synthesis markers) and campesterol, sitosterol, and cholestanol (cholesterol absorption markers) were measured by gas-liquid chromatography in 103 FCH patients and 240 normolipidemic relatives (NLR). Squalene, desmosterol, and lathosterol levels were 6% (0.078), 31%, (P<0.001) and 51% (P<0.001) higher in FCH as compared to NLR, and these differences were especially pronounced in women. An interaction with obesity was also noted for a subset of these markers. We did not observe any apparent differences for the cholesterol absorption markers among FCH patients and NLR.. Our data indicate that both men and women with FCH have alterations in the cholesterol synthesis pathway, resulting in 51% higher levels of lathosterol (and additionally desmosterol in women). Plasma levels of the cholesterol precursor sterol squalene were only slightly increased (6%), suggesting enhanced conversion of squalene to lathosterol in this disorder.

Topics: Adult; Aged; Biomarkers; Cholestanol; Cholesterol; Desmosterol; Female; Humans; Hyperlipidemia, Familial Combined; Intestinal Absorption; Male; Middle Aged; Phytosterols; Sex Characteristics; Sitosterols; Squalene

The aim of the present study was to evaluate the role of cholesterol metabolism in the development of atheromatous artery disease.. Serum synthesis (cholesterol precursors) and absorption markers (cholestanol, campesterol, sitosterol, and avenasterol) were related to coronary risk factors and vascular structure in a population-based sample of 468 randomly selected 33-39-year-old men on their regular habitual diet. Carotid artery intima-media thickness (IMT) and serum lipids (including cholesterol) and sterols were measured in 2001, and the subjects were ranked to decreasing cholesterol synthesis depicted by serum cholestanol quartiles defined 21 years earlier in adolescence.. Serum cholesterol was correlated with absorption (e.g. serum campesterol, p<0.05), but not with synthesis, or with cholestanol quartiles. Cholesterol metabolism (synthesis/absorption markers) decreased linearly (about 50%) with the increasing cholestanol quartiles. IMT differed between the age groups, but not between cholestanol quartiles. Serum triglycerides, apoprotein B, and body mass index decreased, and non-HDL cholesterol/apoprotein B values increased between the cholestanol quartiles, whereas LDL cholesterol was unchanged. Cholesterol synthesis markers were related to blood pressure and serum triglycerides, and negatively to HDL cholesterol level in total population and in most of the cholestanol quartiles (p from 0.05 to 0.001).. Variables of metabolic syndrome accumulated in quartiles of high synthesis of cholesterol. Non-cholesterol sterols were related to many classic coronary risk factors, but virtually not to serum cholesterol or vascular structure.

Topics: Adolescent; Adult; Carotid Arteries; Child; Cholestanol; Cholesterol; Coronary Disease; Follow-Up Studies; Humans; Male; Phytosterols; Risk Factors; Sitosterols; Sterols; Tunica Intima; Tunica Media; Ultrasonography

The replication of plus-strand RNA viruses depends on subcellular membranes. Recent genome-wide screens have revealed that the sterol biosynthesis genes ERG25 and ERG4 affected the replication of Tomato bushy stunt virus (TBSV) in a yeast model host. To further our understanding of the role of sterols in TBSV replication, we demonstrate that the downregulation of ERG25 or the inhibition of the activity of Erg25p with an inhibitor (6-amino-2-n-pentylthiobenzothiazole; APB) leads to a 3- to 5-fold reduction in TBSV replication in yeast. In addition, the sterol biosynthesis inhibitor lovastatin reduced TBSV replication by 4-fold, confirming the importance of sterols in viral replication. We also show reduced stability for the p92(pol) viral replication protein as well as a decrease in the in vitro activity of the tombusvirus replicase when isolated from APB-treated yeast. Moreover, APB treatment inhibits TBSV RNA accumulation in plant protoplasts and in Nicotiana benthamiana leaves. The inhibitory effect of APB on TBSV replication can be complemented by exogenous stigmasterol, the main plant sterol, suggesting that sterols are required for TBSV replication. The silencing of SMO1 and SMO2 genes, which are orthologs of ERG25, in N. benthamiana reduced TBSV RNA accumulation but had a lesser inhibitory effect on the unrelated Tobacco mosaic virus, suggesting that various viruses show different levels of dependence on sterol biosynthesis for their replication.

Topics: Cholesterol; Enzyme Inhibitors; Gene Silencing; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Lovastatin; Mixed Function Oxygenases; Nicotiana; Oxidoreductases; Phytosterols; Plant Proteins; Protoplasts; RNA-Dependent RNA Polymerase; RNA, Viral; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Sterols; Stigmasterol; Thiazoles; Tombusvirus; Viral Proteins; Virus Replication

Intravenous lipid constituents have different effects on various biological processes. Some of these effects are protective, while others are potentially adverse. Phytosterols, in particular, seem to be implicated with parenteral nutrition-associated cholestasis. The aim of this study is to determine the amount of plant and animal sterols present in lipid formulations derived from different oil sources. To this end, animal (cholesterol) and plant (beta-sitosterol, campesterol, and stigmasterol) sterols in seven different commercially available intravenous lipid emulsions (ILEs) were quantified by capillary gas chromatography after performing a lipid extraction procedure. The two major constituents of the lipid emulsions were cholesterol (range 14-57% of total lipids) and beta-sitosterol (range 24-55%), followed by campesterol (range 8-18%) and stigmasterol (range 5-16%). The fish oil-derived formulation was an exception, as it contained only cholesterol. The mean values of the different sterols were statistically different across ILEs (P = 0.0000). A large percentage of pairwise comparisons were also statistically significant (P = 0.000), most notably for cholesterol and stigmasterol (14 out of 21 for both), followed by campesterol (12 out 21) and beta-sitosterol (11 out 21). In conclusion, most ILEs combined significant amounts of phytosterols and cholesterol. However, their phytosterols:cholesterol ratios were reversed compared to the normal human diet.

Topics: Cholestasis; Cholesterol; Fat Emulsions, Intravenous; Fish Oils; Humans; Parenteral Nutrition, Total; Phytosterols; Sitosterols; Stigmasterol

Current guidelines strongly recommend the identification of genetic forms of hypercholesterolemia (HC) during childhood.The usefulness of non-cholesterol sterols (NCS) in the diagnosis of genetic HC has not been fully explored. Plasma NCS were measured by gas chromatography/mass spectrometry (GC/MS) in 113 children with hypercholesterolemia affected by: autosomal dominant hypercholesterolemia (ADH), familial combined hyperlipidemia(FCHL), polygenic hypercholesterolemia (PHC), and in 79 controls to evaluate: i) plasma NCS profile in different genetic HC and ii) the usefulness of NCS for the diagnosis of HC beyond current clinical criteria. ADH was characterized by raised lathosterol/total cholesterol (TC) and reduced phytosterols/TC ratios, indicative of increased cholesterol synthesis. FCHL showed a slight increase of lathosterol/TC ratio, whereas PHC showed increased phytosterols/TC ratios, indicative of increased cholesterol absorption. In a post hoc discriminant analysis of patients with HC, lipid values correctly classified the 73% (14 of 19) of ADH, whereas the inclusion of plasma sterols allowed the correct identification of all 19 patients with ADH. FCHL was not differentiated from PHC (62 versus 69%).In conclusion, NCS measurement showed that cholesterol plasma levels are related to the cholesterol synthesis in ADH and to cholesterol absorption in PHC. NCS improve the detection of ADH in pediatric patients, whereas FCHL diagnosis is not improved.

Topics: Adolescent; Biomarkers; Case-Control Studies; Child; Cholesterol; Discriminant Analysis; Female; Gas Chromatography-Mass Spectrometry; Genetic Predisposition to Disease; Humans; Hyperlipidemia, Familial Combined; Hyperlipoproteinemia Type II; Italy; Male; Multifactorial Inheritance; Phytosterols; Predictive Value of Tests; Sitosterols; Sterols

We generated transgenic lines of Arabidopsis thaliana with an RNA interference construct that expressed hairpin double-stranded RNA for DET2:DWF4:SMT2 to induce sequence-specific RNA silencing. In transgenic plants, expressions of DET2, DWF4, and SMT2 were simultaneously reduced, and the campesterol content was increased by up to 420% compared to the level in the wild-type plant. Triple knock-down of the DET2, DWF4, and SMT2 enzymes also resulted in reduction of brassinosteroid (BR)-specific biosynthesis intermediates. Transgenic plants harboring the RNA interference construct displayed a semi-dwarf phenotype due to altered development. Our findings indicate that redesigning of plant architecture is possible through simultaneous suppression of multiple genes involved in BR biosynthesis.

Topics: Arabidopsis; Arabidopsis Proteins; Cholesterol; Cytochrome P-450 Enzyme System; DNA, Complementary; Gene Expression Regulation, Plant; Gene Knockdown Techniques; Genes, Plant; Methyltransferases; Phenotype; Phytosterols; Plant Growth Regulators; Plants, Genetically Modified; Reverse Transcriptase Polymerase Chain Reaction; RNA Interference; RNA, Double-Stranded; RNA, Plant; Steroids

Moderately elevated levels of plasma plant sterols have been suspected to be causally involved in atherosclerosis. The aim of this study was to investigate whether plant sterols and other markers of sterol metabolism predicted all-cause and cardiovascular mortality in participants of the Ludwigshafen Risk and Cardiovascular health (LURIC) study. A total of 1,257 individuals who did not use statins and at baseline had a mean (+/- SD) age of 62.8 (+/- 11.0) years were included in the present analysis. Lathosterol, cholestanol, campesterol, and sitosterol were measured to estimate cholesterol synthesis and absorption. The mean (+/- SD) time of the follow-up for all-cause and cardiovascular mortality was 7.32 (+/- 2.3) years. All-cause (P = 0.001) and cardiovascular (P = 0.006) mortality were decreased in the highest versus the lowest lathosterol to cholesterol tertile. In contrast, subjects in the third cholestanol to cholesterol tertile had increased all-cause (P < 0.001) and cardiovascular mortality (P = 0.010) compared with individuals in the first tertile. The third campesterol to cholesterol tertile was associated with increased all-cause mortality (P = 0.025). Sitosterol to cholesterol tertiles were not significantly related to all-cause or cardiovascular mortality. The data suggest that high absorption and low synthesis of cholesterol predict increased all-cause and cardiovascular mortality in LURIC participants.

Topics: Absorption; Cardiovascular Diseases; Cholestanol; Cholesterol; Humans; Male; Middle Aged; Phytosterols; Prognosis; Risk; Sitosterols

This study investigates the role of the fungal sterol ergosterol as a general elicitor in the triggering of plant innate immunity in sugar beet. Evidence for this specific function of ergosterol is provided by careful comparison with cholesterol and three plant sterols (stigmasterol, campesterol, sitosterol), which do not enable the integrity of responses leading to elicitation. Our results demonstrate the modification of H(+) flux by ergosterol, due to the direct inhibition of the H(+)-ATPase activity on plasma membrane vesicles purified from leaves. The ergosterol-induced oxidative burst is related to enhanced NADPH-oxidase and superoxide dismutase activities. The similar effects obtained with the fungal elicitor chitosan further reinforce the particular role of ergosterol in the induced defences. The involvement of salicylic acid and/or jasmonic acid signalling in the ergosterol-enhanced plant non-host resistance is also studied. The possible link between ergosterol-triggered plant innate immunity and its putative impact on the structural organization of plant plasma membrane are discussed in terms of the ability of this fungal sterol to promote the formation of lipid rafts.

Topics: Beta vulgaris; Biological Transport; Blotting, Western; Cell Membrane; Cholesterol; Electrophoresis, Polyacrylamide Gel; Enzyme Activation; Enzyme-Linked Immunosorbent Assay; Ergosterol; Hydrogen Peroxide; Hydrogen-Ion Concentration; Phytosterols; Plant Leaves; Sitosterols; Stigmasterol

Maca is an Andean crop of the Brassicaceae family which is mainly known for its fertility-enhancing properties following consumption. The hypocotyls display various colours ranging from white to black. Each colour has different biological effects. The aim of this study was to analyse the concentrations of major secondary metabolites in hypocotyls and leaves of maca in a controlled planting experiment in the Peruvian Andes at 4130 m above sea level. The effects of colour type and of previous cultivation of the field were examined.. In the hypocotyls, the colour type effect was significant for most secondary metabolites; exceptions were beta-sitosterol and campesterol. The lead-coloured, yellow and violet maca hypocotyls were rich in glucosinolates, macaene and macamides, respectively. Previous cultivation affected macaene, campesterol and indole glucosinolate concentrations. Effects on metabolite concentrations in the leaves were minor. Hypocotyls were richer in macaene, macamides and glucosinolates than were leaves, and were poorer in beta-sitosterol and total phenols.. Colour type has to be considered in maca production, as colour associates with variations in concentrations of distinct bioactive metabolites. Leaves may be interesting for animal nutrition purposes as they contain essentially the same secondary metabolites as the hypocotyls but in clearly lower concentrations.

Topics: Agriculture; Altitude; Cholesterol; Glucosinolates; Hypocotyl; Indoles; Lepidium; Linoleic Acids; Linolenic Acids; Nutritive Value; Organ Specificity; Palmitic Acids; Peru; Phytosterols; Pigmentation; Plant Leaves; Polyunsaturated Alkamides; Sitosterols; Soil; Species Specificity

A convenient synthesis of sidechain-modified phytosterols is achieved via a temporary masking of the stigmasterol 5,6-alkene as an epoxide. Following performance of the desired modification, the alkene is regenerated through a mild deoxygenation. The approach is applied to the syntheses of beta-sitosterol and campesterol acetate, and suggests a facile route to the (Z)-isomers of Delta(22-23) phytosterols.

Topics: Alkenes; Cholesterol; Epoxy Compounds; Phytosterols; Sitosterols

Patients with dyslipidemia and advanced renal failure are at markedly increased risk of cardiovascular morbidity and mortality. We evaluated the efficacy and safety of ezetimibe administration to patients with endstage renal failure (ESRF) who are undergoing hemodialysis. Ezetimibe at 10 mg/day was given to 20 patients for 12 weeks. Efficacy was determined by monitoring lipids, and safety was determined by monitoring clinical and laboratory parameters. We also evaluated the effects of ezetimibe on surrogate markers of cholesterol absorption and synthesis. Compared to baseline values, LDL-cholesterol (LDL-C) was reduced by 24.9% (p<0.005) after 12 weeks of ezetimibe administration. Treatment with ezetimibe did not change HDL-cholesterol, triglyceride and HbA1c values but caused a significant reduction in remnant like particles-cholesterol (RLP-C, p<0.05) and high-sensitive C-reactive protein (hsCRP, p<0.05). Ezetimibe therapy decreased cholesterol absorption markers (campesterol and sitosterol) and increased a marker of cholesterol synthesis (lathosterol). A highly significant correlation was observed between alterations in LDL-C and campesterol levels in response to ezetimibe therapy. No patients reported musculoskeletal symptoms. None of the patients experienced elevations in their creatine kinase or liver transaminase levels. Ezetimibe not only reduced serum LDL-C, but also RLP-C and hsCRP, in ESRF patients. Inhibition of cholesterol absorption by ezetimibe is an important therapeutic option in these patients due to its efficacy and safety.

Topics: Aged; Anticholesteremic Agents; Azetidines; C-Reactive Protein; Cholesterol; Dyslipidemias; Ezetimibe; Female; Glycated Hemoglobin; Humans; Linear Models; Male; Middle Aged; Phytosterols; Renal Dialysis; Renal Insufficiency; Triglycerides

Changes in the balance of cholesterol absorption and synthesis and moderately elevated plasma plant sterols have been suggested to be atherogenic. Measuring cholestanol, lathosterol, campesterol, and sitosterol, we investigated the relationships of cholesterol metabolism and plasma plant sterols with the severity of coronary artery disease (CAD) in 2,440 participants of the Ludwigshafen Risk and Cardiovascular health (LURIC) study. The coronary status was determined by angiography, and the severity of CAD was assessed by the Friesinger Score (FS). An increase in the ratio of cholestanol to cholesterol was associated with high FS (P = 0.006). In contrast, a high ratio of lathosterol to cholesterol went in parallel with low FS (P < 0.001). Whereas the campesterol to cholesterol ratio significantly correlated with the FS (P = 0.026), the relationship of the sitosterol to cholesterol ratio with the FS did not reach statistical significance in the whole group. Increased campesterol, sitosterol, and cholestanol to lathosterol ratios were associated high FS (P < 0.001). To conclude, there is a modest association of high cholesterol absorption and low cholesterol synthesis with an increased severity of CAD. An atherogenic role of plasma plant sterols themselves, however, seems unlikely in subjects without sitosterolaemia.

Topics: Aged; Cholestanol; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Coronary Artery Disease; Female; Humans; Male; Middle Aged; Phytosterols; Radiography; Sitosterols

Gibberellins (GAs) and brassinosteroids (BRs), two growth-promoting phytohormones, regulate many common physiological processes. Their interactions at the molecular level remain unclear. Here, we demonstrate that OsGSR1, a member of the GAST (GA-stimulated transcript) gene family, is induced by GA and repressed by BR. RNA interference (RNAi) transgenic rice plants with reduced OsGSR1 expression show phenotypes similar to plants deficient in BR, including short primary roots, erect leaves and reduced fertility. The OsGSR1 RNAi transgenic rice shows a reduced level of endogenous BR, and the dwarf phenotype could be rescued by the application of brassinolide. The yeast two-hybrid assay revealed that OsGSR1 interacts with DIM/DWF1, an enzyme that catalyzes the conversion from 24-methylenecholesterol to campesterol in BR biosynthesis. These results suggest that OsGSR1 activates BR synthesis by directly regulating a BR biosynthetic enzyme at the post-translational level. Furthermore, OsGSR1 RNAi plants show a reduced sensitivity to GA treatment, an increased expression of the GA biosynthetic gene OsGA20ox2, which is feedback inhibited by GA signaling, and an elevated level of endogenous GA: together, these suggest that OsGSR1 is a positive regulator of GA signaling. These results demonstrate that OsGSR1 plays important roles in both BR and GA pathways, and also mediates an interaction between the two signaling pathways.

Topics: Brassinosteroids; Cholestanols; Cholesterol; Gene Expression Regulation, Plant; Gibberellins; Oryza; Phenotype; Phytosterols; Plant Growth Regulators; Plant Proteins; Plants, Genetically Modified; RNA Interference; RNA, Plant; Steroids, Heterocyclic; Two-Hybrid System Techniques

The physico-chemical properties of oil from Moringa oleifera seeds from India were determined in the present study. The petroleum ether extracted oil ranged from 27.83 - 45.07% on kernel basis and 15.1-28.4% on whole seed basis in 20 different clones. Leaves and pods showed a good source of vitamin C. Oleic acid (C18:1) has been found to be the major fatty acid being 78.91-85.52% as compared to olive oil, which is considered to be richest source of oleic acid. All the clones from India did not show any presence of behenic acid (C 22:0). The oil was also found to contain high levels of beta-sitosterol ranged from 42.29-47.94% stigmasterol from 13.66-16.61%, campesterol from 12.53-16.63%. The gamma- and delta-tocopherol were found to be in the range of 128.0-146.95, 51.88-63.5 and 55.23-63.84 mg/kg, respectively.

Topics: Ascorbic Acid; Cholesterol; Fatty Acids; gamma-Tocopherol; Genetic Variation; India; Moringa oleifera; Oleic Acid; Olive Oil; Phytosterols; Plant Oils; Seeds; Sitosterols; Stigmasterol; Tocopherols

To show tracking of cholesterol metabolism, the ratios to cholesterol of e.g. serum cholestenol, desmosterol, and lathosterol, reflecting cholesterol synthesis, and cholestanol, campesterol, avenasterol and sitosterol, reflecting cholesterol absorption, were measured 21 years apart.. In random population samples initially comprising 12- (n=162), 15- (n=158), and 18-year-old (n=148) males participating in the Cardiovascular Risk in Young Finns Study, serum sterols and squalene were measured with gas-liquid chromatography in 1980 and 2001. Quartiles of cholestanol, indicating low to high cholesterol absorption, were defined from the cholestanol values in 1980. Serum cholesterol increased in the oldest age group only, but synthesis markers (except desmosterol) increased in all age groups after the follow-up (e.g. lathosterol, total population +47.3+/-2.6% (SE), P<0.001). Campesterol (+69.0+/-3.0%, P<0.001) and sitosterol increased, avenasterol was unchanged, and cholestanol decreased (-6.2+/-0.7%, P<0.001), respectively. The 1980 synthesis and absorption markers were interrelated with respective values 21 years later in all age groups and quartiles (e.g. lathosterol, total population 1980 vs. 2001 r=0.460, cholestanol 1980 vs. 2001 r=0.593, P<0.001 for both). Synthesis markers were highest in the first and lowest in the fourth quartile both in 1980 and 2001 (e.g. 2001, desmosterol, quartile 1, 99+/-9, quartile 4, 83+/-2 microg/mg of cholesterol, P<0.05).. Cholesterol metabolism is significantly tracked in adolescent males over the follow-up of 21 years. Thus, high cholesterol synthesis and low absorption characterize subjects with the lowest cholestanol quartile, while those with the highest quartile have low synthesis and high absorption in both adolescence and later in young adult life.

Topics: Adolescent; Adult; Age Factors; Biomarkers; Body Mass Index; Cardiovascular Diseases; Child; Child, Preschool; Cholestanol; Cholesterol; Chromatography, Gas; Chromatography, Liquid; Desmosterol; Female; Finland; Follow-Up Studies; Humans; Intestinal Absorption; Male; Phytosterols; Population Surveillance; Registries; Risk Factors; Sitosterols; Time Factors

Much interest has focused on the cholesterol-lowering effects of phytosterols (plant sterols) but limited data suggests they may also possess anti-carcinogenic activity. Conjugated linoleic acids (CLA), sourced from meat and dairy products of ruminant animals, has also received considerable attention as a potential anti-cancer agent. Therefore, the aims of this project were to (i) examine the effects of phytosterols and CLA on the viability and growth of human intestinal Caco-2 cells and (ii) determine their potential genoprotective (comet assay), COX-2 modulatory (ELISA) and apoptotic (Hoechst staining) activities. Caco-2 cells were supplemented with the phytosterols campesterol, beta-sitosterol, or beta-sitostanol, or a CLA mixture, or individual CLA isomers (c10t12-CLA, t9t11-CLA) for 48 h. The three phytosterols, at the highest levels tested, were found to reduce both the viability and growth of Caco-2 cells while CLA exhibited isomer-specific effects. None of the phytosterols protected against DNA damage. At a concentration of 25 microM, both c10t12-CLA and t9t11-CLA enhanced (P<0.05) oxidant-induced, but not mutagen-induced, DNA damage. Neither the phytosterols nor CLA induced apoptosis or modulated COX-2 production. In conclusion, campesterol, beta-sitosterol, beta-sitostanol, c10t12-CLA, and t9t11-CLA were not toxic to Caco-2 cells, at the lower levels tested, and did not exhibit potential anti-carcinogenic activity.

Topics: Caco-2 Cells; Cell Membrane; Cell Survival; Cholesterol; Comet Assay; Cyclooxygenase 2; DNA Damage; Enzyme-Linked Immunosorbent Assay; Humans; Hydrogen Peroxide; L-Lactate Dehydrogenase; Linoleic Acid; Methylnitronitrosoguanidine; Mutagens; Phytosterols; Protective Agents; Sitosterols

To analyze the phytosterol content in food plant materials and Chinese traditional herbal medicines commonly used in China.. 18 kinds of food plant materials and 32 kinds of Chinese traditional herbal medicines, which were commonly used in functional food, were chosen as samples. The contents of beta-sitosterol, campesterol, stigmasterol, beta-sitostanol were analyzed by GC methods and the percent of each ingredient were calculated.. The contents of phytosterols in 18 kinds of food plant materials were from 14.8 mg/100 g to 208.3 mg/100 g, while the content of phytosterols in 32 Chinese traditional herbal medicines were from 9.4 mg/100 g to 280.3 mg/100 g. In most samples, beta-sitosterol is the largest part of total phytosterol.. Phytosterols were existed in 50 kinds of food plant materials and Chinese traditional herbal medicines commonly used in functional food, maybe phytosterol is an important functional ingredient in some plant materials.

Topics: Cholesterol; Chromatography, Gas; Drugs, Chinese Herbal; Phytosterols; Plants, Medicinal; Sitosterols; Stigmasterol; Vegetables

Dihydroactinidiolide (1) and a mixture of sterols [campesterol (2), stigmasterol (3) and beta-sitosterol (4)], together with the previously isolated individual compounds beta-sitosterol (4), 2,4-di-tert-butylphenol (5), alpha-tocopherol (6), phytol (7) were isolated from the active ethyl acetate fraction of Pereskia bleo (Kunth) DC. (Cactaceae) leaves. Cytotoxic activities of the above mentioned compounds against five human carcinoma cell lines, namely the human nasopharyngeal epidermoid carcinoma cell line (KB), human cervical carcinoma cell line (CasKi), human colon carcinoma cell line (HCT 116), human hormone-dependent breast carcinoma cell line (MCF7) and human lung carcinoma cell line (A549); and non-cancer human fibroblast cell line (MRC-5) were investigated. Compound 5 possessed very remarkable cytotoxic activity against KB cells, with an IC(50 )value of 0.81microg/mL. This is the first report on the cytotoxic activities of the compounds isolated from Pereskia bleo.

Topics: alpha-Tocopherol; Antineoplastic Agents, Phytogenic; Cactaceae; Cell Line, Tumor; Cholesterol; Drug Screening Assays, Antitumor; Humans; Molecular Structure; Phenols; Phytol; Phytosterols; Plant Leaves; Sitosterols; Stigmasterol

We investigated the associations between indices of cholesterol metabolism and features of the metabolic syndrome (MS) in the presence and absence of type-2 diabetes (T2DM).. Men with the MS (N=140) and 10 age- and sex-matched controls were recruited. Plasma lathosterol and campesterol were measured by gas chromatography-mass spectrometry, and their ratios to total cholesterol were used to estimate cholesterol metabolism.. Compared with healthy controls, MS subjects had significantly higher lathosterol:cholesterol and lower campesterol:cholesterol ratios (p<0.05). In the MS subjects without T2DM (N=82), campesterol:cholesterol ratio was positively associated with age and negatively associated with plasma triglyceride and insulin concentrations, while in MS subjects with T2DM (N=58), the ratio was positively associated with age and adiponectin concentration, and negatively associated with BMI and insulin. Age and fasting insulin were independent predictors of campesterol:cholesterol ratio in MS subjects with T2DM. There was a significant negative association between plasma lathosterol:cholesterol with campesterol:cholesterol ratio (r=-0.436, p=0.014) in MS subjects without T2DM but not in MS subjects with T2DM.. Cholesterol absorption efficiency was lower and cholesterol synthesis higher in MS subjects with or without T2DM compared with healthy individuals. Moreover, the reciprocal relationship between cholesterol synthesis and cholesterol absorption is lost in the presence of diabetes.

Topics: Adiponectin; Apolipoprotein A-I; Apolipoproteins; Biomarkers; Blood Glucose; Blood Pressure; Cholesterol; Diabetes Mellitus, Type 2; Female; Gas Chromatography-Mass Spectrometry; Homeostasis; Humans; Male; Metabolic Syndrome; Middle Aged; Obesity; Phytosterols; Reference Values; Triglycerides

A comparative study was performed to determine the free sterols content and composition during the development of three varieties of linseed (H52, O116 and P129). Seed samples were collected at regular intervals from 7 to 60 days after flowering (DAF). Ten compounds were identified: cholesterol, campesterol, brassicasterol, stigmasterol, beta-sitosterol, Delta5-avenasterol, cycloartenol; 24-methylene cycloartanol, obtusifoliol, citrostadienol. The maximum level of 4-desmethylsterols (1,515 mg/100g oil) was reached at 7 DAF in P129 variety. H52 had the highest level of 4-4 dimethylsterols (355 mg/100g oil) at 28 DAF. The greatest amount of 4-monomethylsterols (35 mg/100g oil) was detected in H52 at 14 DAF. During linseed development, beta sitosterol (830 mg/100g oil) was the major 4-desmethylsterols, followed by campesterol (564 mg/100g oil) and stigmasterol (265 mg/100g oil). Some of these compounds followed nearly the same accumulation pattern during linseed maturation.

Topics: Cholestadienols; Cholesterol; Chromatography, Thin Layer; Flax; Flowers; Gas Chromatography-Mass Spectrometry; Phytosterols; Seeds; Sitosterols; Species Specificity; Stigmasterol; Time Factors; Triterpenes

Hypercholesterolemia is a risk factor for aortic stenosis (AS) and for coronary artery disease (CAD). Serum cholesterol concentrations are determined by intestinal cholesterol absorption and endogenous cholesterol synthesis. Vascular effects of differences in cholesterol metabolism in patients with AS are so far unknown. Therefore, the aim of this study was to investigate differences in cholesterol metabolism in relation to vascular diseases in this subset of patients.. In addition to identifying conventional coronary risk factors, we determined plant sterols (indicators of cholesterol absorption) and lathosterol (indicator of cholesterol synthesis) levels in 40 consecutive men and women with AS. Coronary angiograms before the aortic valve replacement determined the extent of CAD.. Patients with a positive history of cardiovascular disease exhibited an increased campesterol-to-lathosterol ratio in plasma (P<0.005) and in aortic valve cusps (P<0.05). The plasma campesterol-to-lathosterol ratio increased with CAD severity (zero, single, two, three-vessel disease; P<0.05). Coronary vessel score strongly correlated with the campesterol-to-lathosterol ratio in plasma (r = 0.52; P<0.001) and in aortic valve cusps (r = 0.33; P<0.03). Logistic regression analysis revealed that the ratio of campesterol-to-lathosterol was the sole predictor of CAD among coronary risk factors tested (P<0.01).. Enhanced absorption and reduced synthesis of cholesterol is related to a positive family history of cardiovascular diseases and the development of concomitant CAD in patients with AS.

Topics: Adult; Aged; Aged, 80 and over; Aortic Valve Stenosis; Biomarkers; Cholesterol; Coronary Angiography; Coronary Disease; Cross-Sectional Studies; Female; Heart Valve Prosthesis Implantation; Homeostasis; Humans; Intestinal Absorption; Logistic Models; Male; Middle Aged; Phytosterols; Risk Assessment; Risk Factors; Severity of Illness Index; Ultrasonography

Rapeseed oil (RSO) is a novel source of plant sterols, containing the unique brassicasterol in concentrations higher than allowed for plant sterol blends in food products in the European Union. Effects of RSO sterols and stanols on aortic atherosclerosis were studied in cholesterol-fed heterozygous Watanabe heritable hyperlipidaemic (Hh-WHHL) rabbits. Four groups (n 18 per group) received a cholesterol-added (2 g/kg) standard chow or this diet with added RSO stanol esters (17 g/kg), RSO stanol esters (34 g/kg) or RSO sterol esters (34 g/kg) for 18 weeks. Feeding RSO stanol esters increased plasma campestanol (P < 0.001) and sitostanol (P < 0.001) and aortic campestanol (P < 0.05) compared with controls. Feeding RSO sterol esters increased concentrations of plasma campesterol (P < 0.001), sitosterol (P < 0.001) and brassicasterol (P < 0.001) and aortic campesterol (P < 0.01). Significantly lower plasma cholesterol (P < 0.001) was recorded in the treated groups after 3 weeks and throughout the study. LDL-cholesterol was reduced 50 % in the high-dose RSO sterol ester (P < 0.01) and high-dose RSO stanol ester (P < 0.001) groups compared with controls. Atherosclerotic lesions were found in three rabbits in each of the RSO stanol ester groups and in one in the RSO sterol ester group. Aortic cholesterol was decreased in the treated groups (P < 0.001) in response to lowering of plasma cholesterol induced by RSO sterol and stanol esters. In conclusion, RSO stanol and sterol esters with a high concentration of brassicasterol were well tolerated. They were hypocholesterolaemic and inhibited experimental atherosclerosis in cholesterol-fed Hh-WHHL rabbits. A significant uptake of plant sterols into the blood and incorporation of campesterol and campestanol into aortic tissue was recorded.

Topics: Animals; Aorta; Atherosclerosis; Cholestadienols; Cholesterol; Cholesterol, Dietary; Fatty Acids, Monounsaturated; Female; Heterozygote; Hyperlipidemias; Lipids; Male; Phytosterols; Plant Oils; Rabbits; Rapeseed Oil; Sitosterols

We elucidated the molecular mechanism(s) underlying sterol trafficking by investigating alterations in gene expression in response to increased retention of dietary phytosterols and phytostanols in stroke-prone spontaneously hypertensive (SHRSP) and normotensive Wistar Kyoto (WKY) inbred rats.. SHRSP and WKY inbred rats were fed a control diet or a diet supplemented with phytosterols or phytostanols (2 g/kg diet).. Intake of phytosterols and phytostanols increased their incorporation in plasma, red blood cells, liver, aorta and kidney, but decreased cholesterol levels in liver and aorta in both rat strains. Phytosterol intake up-regulated mRNA expression of intestinal Npc1l1 and Abcg8, and hepatic Abcg5, Abca1, Cyp27a1 and Hmgcr. Phytostanol intake up-regulated Npc1l1 and Srebp2, but down-regulated Abcg5 mRNA expression in small intestine. Phytostanols also up-regulated Abca1 expression in SHRSP rats, but down-regulated Abca1 expression in WKY inbred rats. Compared to phytosterols, dietary phytostanols reduced phytosterol levels in plasma, red blood cells, and kidney, as well as altered mRNA levels of hepatic Abca1,Cyp27a1, and Hmgcr and intestinal Abcg5/8, Hmgcr and Srebp2.. Altered expression of multiple sterol-regulatory genes may contribute to the incorporation and cholesterol-lowering actions of phytosterols and phytostanols. Phytosterols and phytostanols may act through different mechanism(s) on cholesterol and phytosterol/phytostanol trafficking.

Topics: Animals; Anticholesteremic Agents; Cholestadienols; Cholesterol; Gene Expression Regulation; Hypolipidemic Agents; Jejunum; Liver; Male; Organ Specificity; Phytosterols; Rats; Rats, Inbred SHR; Rats, Inbred WKY; RNA, Messenger; Sitosterols; Sterols

To investigate the dietary phytosterol intake of elderly women in three different cities of China, and to compare the main dietary sources, so that to discuss the relationship of dietary phytosterol intake and serum lipids.. Based on the dietary pattern, women more than 50 years old from Beijing, Hefei and Urumchi were chosen as testers, 80 - 100 people for each city respectively. The dietary survey was done by continues 24 hours review of two days, the plant food were collected and the phytosterol content (include beta-sitosterol, campesterol, stigmasterol, sitostanol) were analyzed by GC methods, the total phytosterols content were calculated. The dietary phytosterol intake were calculated and serum lipids were also analyzed in all the testers.. Testers from Beijing, Hefei and Urumchi were 100, 101 and 84 respectively. The average dietary phytosterol intake of people in Beijing and Hefei were 340.3 mg/d and 313.5 mg/d, the main sources were plant oil and cereals, while the average dietary phytosterol intake of people in Urumchi were 550.4 mg/d, higher than the other two cities (t values were 9.369, 10.420, respectively, both P values < 0.01), the main source in Urumchi was cereal (provide 53.1% of the total phytosterol intake). The laboratory results showed, testers in Urumchi had significantly lower serum TC content ((4.04 +/- 0.78) mmol/L) than that in Beijing ((4.89 +/- 0.91) mmol/L) and Hefei ((4.71 +/- 0.83) mmol/L) (t value were 6.766 and 5.401 respectively, both P values < 0.01); serum TG content in Urumchi((1.01 +/- 0.48) mmol/L) was also lower than that in Beijing ((1.31 +/- 0.53) mmol/L) and Hefei ((1.66 +/- 0.75) mmol/L) (t values were 3.343 and 7.293 respectively, both P values < 0.01); the serum glucose is also lower in testers in Urumchi ((5.02 +/- 2.18) mmol/L) compared with testers in Beijing ((5.69 +/- 1.53) mmol/L, t = 2.561, P < 0.05) and Hefei ((5.78 +/- 1.53) mmol/L, t = 2.934, P < 0.01).. Different dietary pattern result in significantly different dietary phytosterol intake in elder women in three cities, higher, phytosterol intake seemed to contribute to lower serum lipids.

Topics: Aged; Aged, 80 and over; China; Cholesterol; Cholesterol, Dietary; Female; Humans; Lipids; Middle Aged; Phytosterols; Sitosterols; Urban Population

It has been suggested that plant sterol absorption is increased in type 1 diabetes mellitus (T1DM) and that this may relate to the increased cardiovascular risk seen in T1DM. The cardiovascular benefit of lowering low-density lipoprotein-cholesterol with statin medication has also been shown to be influenced by plant sterol absorption.. The relationship between sterol concentrations, coronary artery disease (CAD), and the use of statin medications in T1DM was compared between participants with CAD (Minnesota codes 1.1, 1.2, 1.3, 4.1-4.3, 5.1-5.3, and 7.1; n = 82), from the Pittsburgh Epidemiology of Diabetes Complications (EDC) study, and those without (n = 213). Serum sterol concentrations reflecting cholesterol absorption (β-sitosterol and campesterol) and synthesis (desmosterol and lathosterol) were assayed and analyzed by gas chromatography and were expressed as a ratio of total cholesterol (×10(3)).. No differences were observed in markers of cholesterol absorption between individuals with and without CAD. In patients with CAD, significantly lower levels were observed for both sterol markers reflecting cholesterol synthesis compared with individuals without CAD [desmosterol: 0.34 vs 0.42, respectively (P = 0.003); lathosterol 0.47 vs 0.54, respectively (P = 0.019)]. Further stratification by statin medication use revealed significantly lower levels of synthesis-reflecting sterols in individuals taking statin medication, particularly those with CAD.. Although previous reports suggest that higher levels of cholesterol absorption in T1DM potentially increase cardiovascular risk in this population, the present data suggest no differences in cholesterol absorption between T1DM individuals with and without CAD.

Topics: Adult; Cholesterol; Cholesterol, LDL; Coronary Artery Disease; Desmosterol; Diabetes Mellitus, Type 1; Female; Humans; Male; Middle Aged; Phytosterols; Sitosterols

We investigated the difference between the molecular structures of plant sterols and stanols that affect the solubilization of cholesterol in bile salt micelles (in vitro study). First, the aqueous solubility of beta-sitosterol, beta-sitostanol, and campesterol was determined by considering the specific radioactivity by using a fairly small quantity of each radiolabeled compound. The order of their aqueous solubilities was as follows: cholesterol > campesterol > beta-sitostanol > beta-sitosterol. The maximum solubility of cholesterol and the above mentioned sterol/stanol in sodium taurodeoxycholate and sodium taurocholate solutions (single solubilizate system) was measured. Moreover, the preferential solubilization of cholesterol in bile salt solutions was systematically studied by using different types of plant sterols/stanols. The solubilization results showed that the cholesterol-lowering effect was similar for sterols and stanol. Thermodynamic analysis was applied to these experimental results. The Gibbs energy change (Delta G degrees ) for the solubilization of plant sterols/stanols showed a negative value larger than that for cholesterol.

Topics: Cholesterol; Micelles; Phytosterols; Sitosterols; Solubility; Taurocholic Acid; Taurodeoxycholic Acid; Thermodynamics

Intestinal absorption of plant sterols and stanols is much lower as compared with that of cholesterol; and therefore, serum concentrations are low. Circulating plant sterols and stanols are incorporated into tissues. However, hardly any data are available about tissue distributions of individual plant sterols and stanols, particularly in relation to their serum concentrations. We therefore fed female apolipoprotein E*3-Leiden mice a control diet, a plant sterol-enriched diet (1g/100 g diet), or a plant stanol-enriched diet (1g/100 g diet) for 8 weeks. In the sterol group, serum cholesterol-standardized campesterol and sitosterol concentrations were, respectively, 8 and 7 times higher as compared with those in the control group. Consequently, the serum campesterol-sitosterol ratio remained essentially unchanged. Cholesterol-standardized plant sterol concentrations increased significantly in all analyzed tissues, except brain. However, the campesterol-sitosterol ratio also increased in all tissues (except in liver and spleen), suggesting that campesterol is preferentially incorporated over sitosterol in those tissues. For the stanol group, serum plant stanol concentrations also increased; but the increase was but less pronounced. We conclude that, in apolipoprotein E*3-Leiden mice, campesterol is preferentially incorporated into most tissues over sitosterol, which cannot be deduced from changes in serum concentrations.

Topics: Animals; Apolipoprotein E3; Cholesterol; Diet; Female; Mice; Mice, Transgenic; Osmolar Concentration; Phytosterols; Sitosterols; Tissue Distribution

An accurate and sensitive method, combining soxhlet extraction, solid phase-extraction and capillary gas chromatography is described for the quantitative determination of one triterpene (lupeol) and three sterols (stigmasterol, campesterol and beta-sitosterol) and the detection of another triterpene (alpha-amyrin) from the aerial part of Justicia anselliana. This is the first method allowing the quantification of sterols and triterpenes in this plant. It has been fully validated in order to be able to compare the sterol and triterpene composition of different samples of J. anselliana and therefore help to explain the allelopathic activity due to these compounds. This method showed that the aerial part of J. anselliana contained (292+/-2)mg/kg of lupeol, (206+/-1)mg/kg of stigmasterol, (266+/-2)mg/kg of campesterol and (184+/-9)mg/kg of beta-sitosterol.

Topics: Acanthaceae; Calibration; Cholesterol; Chromatography, Gas; Molecular Structure; Pentacyclic Triterpenes; Phytosterols; Plant Components, Aerial; Reference Standards; Reproducibility of Results; Sensitivity and Specificity; Sitosterols; Solid Phase Extraction; Sterols; Stigmasterol; Triterpenes

Serum ratios to cholesterol of lathosterol, and of cholestanol, campesterol and sitosterol measure respective relative cholesterol synthesis and absorption, but their clinical applicability is not known in evaluation of cholesterol metabolism under different dietary conditions. We compared relative synthesis and absorption of cholesterol to the respective absolute ones in healthy male volunteers (n 29) on four subsequent diets: baseline home (HD), low-cholesterol low-fat (LCLF), high-cholesterol low-fat (HCLF) and low-cholesterol high-fat (LCHF). Serum lipids, lipoproteins, sterols, fractional cholesterol absorption and sterol synthesis were examined. HCLF and LCHF decreased fractional cholesterol absorption by approximately 23-27 % from baseline HD (P < 0.05) and increased the levels of total and LDL-cholesterol in serum from LCLF by approximately 9-14 % (P < 0.05). On HCLF, bile acid synthesis was high (P < 0.05 for each), and absolute cholesterol synthesis tended to be higher than on HD and LCHF (NS). Relative synthesis was positively associated with absolute cholesterol synthesis, but inversely with relative absorption during each diet (P < 0.05). The relative absorption markers were interrelated in each diet, and were also associated with fractional absorption of cholesterol in each diet but HD. In conclusion, relative markers of cholesterol absorption and synthesis reflect changes in cholesterol metabolism despite the amount of dietary fat and cholesterol consumed, but their validity with this respect is strengthened by controlled diets in metabolic studies. Additions of cholesterol and fat to a diet low in fat and cholesterol cause practically equal changes in the serum lipid profiles, whereas synthesis of cholesterol (NS) and bile acids (P < 0.05) were higher with the high-cholesterol feeding.

Topics: Biomarkers; Cholesterol; Cholesterol, Dietary; Diet; Dietary Fats; Feces; Follow-Up Studies; Humans; Intestinal Absorption; Lipids; Lipoproteins; Male; Middle Aged; Phytosterols; Sitosterols; Sterols

The effect of storage on sterol oxidation of ready-to-eat infant foods was evaluated. Two different liquid infant foods (honey or fruits flavors), prepared with milk and cereals, were stored for 0, 2, 4, 7 and 9 months at 25 degrees C. Sterol oxidation products (SOP) were isolated by cold saponification, purified by silica solid-phase extraction, and analyzed by gas chromatography (GC) and GC-mass spectrometry. beta-Sitosterol was the most representative sterol, followed by cholesterol and campesterol. No significant differences in the total and single SOP content (0.8-1 mg/kg of product) were observed with respect to storage time and type of sample; the main SOP found was 7-ketositosterol (<0.2 mg/kg of product). The extent of stigmasterol oxidation (2.9%) was higher than that of cholesterol (1.9%) and beta-sitosterol (1.4%). The type and quality of raw materials, as well as the processing conditions, seem to greatly influence SOP formation and accumulation in infant foods.

Topics: Cholesterol; Fatty Acids; Food Preservation; Infant Food; Oxidation-Reduction; Phytosterols; Sitosterols; Sterols

Surrogate serum markers of cholesterol synthesis (e.g. squalene, lathosterol) and absorption (e.g. cholestanol, campesterol) were studied in adolescent boys to show whether homeostasis of cholesterol metabolism is maintained in different age cohorts and within different absorption levels.. In random population samples of 12- (n=162), 15- (n=158), and 18- (n=148) year-old boys participating in Cardiovascular Risk in Young Finns Study serum sterols and squalene were measured with gas-liquid chromatography at baseline, and expressed as ratios to cholesterol. Quartiles of cholestanol indicating low to high cholesterol absorption were defined from whole population.. Age-dependent decrease of serum cholesterol was associated with increased synthesis and decreased absorption of cholesterol (e.g. campesterol 205+/-6 vs. 176+/-4 in 12- vs. 18-year-old, p<0.05). In whole population, synthesis and absorption markers were interrelated indicating maintenance of homeostasis of cholesterol metabolism. Synthesis markers decreased and those of absorption increased linearly from first (low absorption) to fourth cholestanol quartile (high absorption). Correlation between synthesis and absorption, however, was significant in the lowest quartile only (lathosterol vs. campesterol, quartile 1, r=-0.283, p<0.05; quartile 4, r=-0.070, NS).. Even though cholesterol absorption and synthesis are usually changed in opposite directions, in cases with high absorption the maintenance of homeostasis of cholesterol metabolism can be lost, so that synthesis and absorption of cholesterol are changed independently of each other.

Topics: Adolescent; Age Factors; Body Mass Index; Child; Cholestanol; Cholesterol; Finland; Homeostasis; Humans; Male; Phytosterols; Skinfold Thickness; Squalene

The plant sterols campesterol, beta-sitosterol and beta-sitostanol were investigated for potential immunomodulatory effects in Jurkat T cells. Treatments involved supplementing cells with or without concanavalin A (ConA) or phorbol-12-myristate-13-acetate plus ionomycin (PMA+IoM) in the presence or absence of increasing concentrations (10-100 microM) of each plant sterol for 24 h. None of the plant sterols significantly affected mitogen-stimulated IL-4, IL-10 or IFN-gamma production. However, campesterol, beta-sitosterol and beta-sitostanol significantly suppressed mitogen-induced IL-2 production in a dose-dependent manner. Both bisindolylmaleimide-I (BIM-I), a specific protein kinase C (PKC) inhibitor, and the immunosuppressant drug known as Tacrolimus (FK506), an IL-2 inhibitor, prevented mitogen-stimulated IL-2 production in Jurkat cells. Treatment with PMA+IoM alone significantly increased PKC activity and the presence of BIM-I prevented PKC activation by PMA+IoM. Following 24 h treatments, the plant sterols did not affect PMA+IoM-enhanced PKC activity, cellular calcium content or calcineurin activity. Intracellular cyclic 3',5'-adenosine monophosphate (cAMP) levels were significantly reduced by PMA+IoM. The presence of FK506 prevented a PMA+IoM-induced reduction of intracellular cAMP. Likewise the plant sterols behaved in a similar manner as FK506. Our findings suggest that the suppression of IL-2 by the plant sterols was not mediated via PKC inhibition and that their effects occurred possibly via cAMP modulation and/or a calcium/calcineurin-independent pathway.

Topics: Cell Division; Cell Survival; Cholesterol; Concanavalin A; Cytokines; Enzyme Inhibitors; Humans; Immunologic Factors; Immunosuppressive Agents; Indoles; Interleukin-2; Jurkat Cells; Lymphocyte Activation; Maleimides; Phytosterols; Protein Kinase C; Sitosterols; T-Lymphocytes; Tacrolimus; Tetradecanoylphorbol Acetate

Some studies have suggested that a modest increase of plant sterol levels is a risk factor for coronary artery disease (CAD). We studied the relationship between plant sterol levels and CAD risk in a prospective nested case-control study consisting of 373 cases and 758 controls. Sitosterol and campesterol concentrations did not differ between cases and controls [sitosterol, 0.21 vs. 0.21 mg/dl (P = 0.1); campesterol, 0.31 vs. 0.32 mg/dl (P = 0.5)]. The sitosterol-to-cholesterol ratio was significantly lower in cases than in controls (1.19 vs. 1.29 microg/mg; P = 0.008), whereas the campesterol-to-cholesterol ratio did not differ significantly (1.78 vs. 1.88 microg/mg; P = 0.1). Plant sterol concentrations correlated positively with cholesterol levels and inversely with body mass index and triglyceride and lathosterol concentrations. Among individuals in the highest tertile of the sitosterol concentration, the unadjusted odds ratio (OR) for future CAD was 0.75 [95% confidence interval (CI) = 0.56-1.01]. After adjustment for traditional risk factors, the OR was 0.79 (95% CI = 0.56-1.13). For the campesterol concentration, the unadjusted OR was 0.95 (95% CI = 0.71-1.29) and the adjusted OR was 0.97 (95% CI = 0.68-1.39). In this large prospective study, higher levels of plant sterols, at least in the physiological range, do not appear to be adversely related to CAD in apparently healthy individuals.

Topics: Aged; Body Mass Index; Case-Control Studies; Cholesterol; Coronary Disease; England; Female; Humans; Lipids; Male; Middle Aged; Netherlands; Phytosterols; Prospective Studies; Triglycerides

Molecular cloning of the gene encoding sterol Delta7 reductase from the filamentous fungus Mortierella alpina 1S-4, which accumulates cholesta-5,24-dienol (desmosterol) as the main sterol, revealed that the open reading frame of this gene, designated MoDelta7SR, consists of 1,404 bp and codes for 468 amino acids with a molecular weight of 53,965. The predicted amino acid sequence of MoDelta7SR showed highest homology of 51% with that of sterol Delta7 reductase (EC 1.3.1.21) from Xenopus laevis (African clawed frog). Heterologous expression of the MoDelta7SR gene in yeast Saccharomyces cerevisiae revealed that MoDelta7SR converts ergosta-5,7-dienol to ergosta-5-enol (campesterol) by the activity of Delta7 reductase. In addition, with gene silencing of MoDelta7SR gene by RNA interference, the transformant accumulated cholesta-5,7,24-trienol up to 10% of the total sterols with a decrease in desmosterol. Cholesta-5,7,24-trienol is not detected in the control strain. This indicates that MoDelta7SR is involved in desmosterol biosynthesis in M. alpina 1S-4. This study is the first report on characterization of sterol Delta7 reductase from a microorganism.

Topics: Animals; Base Sequence; Cholecalciferol; Cholesterol; Cloning, Molecular; Desmosterol; DNA, Fungal; Ergosterol; Gas Chromatography-Mass Spectrometry; Gene Expression; Gene Silencing; Molecular Sequence Data; Molecular Structure; Molecular Weight; Mortierella; Open Reading Frames; Oxidoreductases Acting on CH-CH Group Donors; Phytosterols; Saccharomyces cerevisiae; Sequence Homology, Amino Acid; Sterols; Xenopus laevis

The consumption of products enriched with plant sterol or stanol esters lowers serum total and LDL-cholesterol concentrations, thereby most likely reducing the risk of coronary heart disease. However, using plant sterol (not plant stanol) enriched products elevates serum plant sterol concentrations in humans. This may be unwanted because health effects of elevated serum plant sterol concentrations are still controversial. Within postlaunch monitoring of functional foods, we compared serum plant sterol and plant stanol concentrations among users of plant sterol (n = 67) or plant stanol (n = 13) enriched margarines with those of matched nonusers (n = 81) in the ongoing Dutch Doetinchem cohort study. Subjects (aged 29-67 y) were examined in 1994-1998 (before the introduction of enriched margarines) and re-examined in 1999-2003. Serum concentrations of plant sterols and stanols were measured in samples from nonfasting subjects by GLC-MS. Intake of plant sterols was 1.1 +/- 0.6 g/d and was associated with a decrease of serum total cholesterol concentration of 0.25 +/- 0.91 mmol/L (4%, P < 0.05), a change that differed (P < 0.05) from the nonsignificant increase in nonusers (+2%, 0.12 +/- 0.78 mmol/L, P = 0.16). Cholesterol-standardized serum sitosterol and campesterol increased in plant sterol users by 22% (P < 0.0001) and 103% (P < 0.0001), respectively. Cholesterol-standardized serum sitostanol and campestanol increased in plant stanol users by 197% (P = 0.02) and 196% (P = 0.01). To our knowledge, these data are the first to show changes in serum cholesterol, plant sterol, and plant stanol concentrations after (long-term) consumption of plant sterol and stanol enriched margarines in a free-living population in a nonexperimental setting. Whether the increased serum sterol concentrations result in adverse side effects needs to be investigated in future postlaunch monitoring studies.

Topics: Adult; Aged; Cholesterol; Cohort Studies; Diet; Female; Humans; Male; Margarine; Middle Aged; Osmolar Concentration; Phytosterols; Sitosterols; Time Factors

Different physicochemical properties of Langmuir films (monolayers) composed of 10 mixed systems of a bile acid, deoxycholic acid (DC) with various plant sterols, such as stigmasterol (Stig), beta-sitosterol (Sito) and campesterol (Camp) and a stanol, cholestanol (Chsta) in addition to an animal sterol, cholesterol (Ch) [these sterols and Chsta are abbreviated as St] and DC with 1:1 St mixtures; (Ch+Chsta), (Ch+Stig), (Stig+Chsta), (Ch+Sito) and (Ch+Camp) on the substrate of 5M aqueous NaCl solution (pH 1.2) at 25 degrees C, were investigated in terms of mean surface area per molecule (A(m)), the partial molecular area (PMA), surface excess Gibbs energy (DeltaG((ex))), interaction parameter (I(p)) as well as activity coefficients (f(1) and f(2)) in 2-D phase of each binary (or ternary) component system and elasticity (Cs(-1)) of formed films; these were analyzed on the basis of the respective surface pressure (pi) versus A(m) isotherms as a function of mole fraction of Sts (X(st)) in the DC/St(s) mixtures at discrete surface pressures. Notable findings are: (i) all the binary component systems did form patched film type monolayers consisting of (a) DC-dominant film solubilizing a trace amount of St molecules and (b) St dominant film dissolving a small amount of DC molecules, (ii) DC in 2-D phase exhibited a transition from LE film to LC film at a constant pressure (pi(C)(1)) accompanied by compression and (iii) DeltaG((ex)) as well as I(p) was found to be greatly dependent on (a) the combinations of DC with different St species and (b) to be markedly varied by a difference in mixing ratio of DC to Sts. Compressibility (or elasticity) analyses and fluorescence microscopy images could support the above findings as well as interpretation.

Topics: Cholesterol; Deoxycholic Acid; Phytosterols; Sitosterols; Unilamellar Liposomes

Campesterol, a plant sterol in nature, is known to have cholesterol lowering and anticarcinogenic effects. Since angiogenesis is essential for cancer, it was surmised that an antiangiogenic effect may be involved in the anticancer action of this compound. This study investigated the effect of campesterol on basic fibroblast growth factor (bFGF)-induced angiogenesis in vitro in human umbilical vein endothelial cells (HUVECs) and an in vivo chorioallantoic membrane (CAM) model. Campesterol isolated from an ethylacetate fraction of Chrysanthemum coronarium L. showed a weak cytotoxicity in non-proliferating HUVECs. Within the non-cytotoxic concentration range, campesterol significantly inhibited the bFGF-induced proliferation and tube formation of HUVECs in a concentration-dependent manner, while it did not affect the motility of HUVECs. Furthermore, campesterol effectively disrupted the bFGF-induced neovascularization in chick chorioallantoic membrane (CAM) in vivo. Taken together, these results support a potential antiangiogenic action of campesterol via an inhibition of endothelial cell proliferation and capillary differentiation.

Topics: Angiogenesis Inhibitors; Animals; Cell Movement; Cell Proliferation; Cells, Cultured; Chick Embryo; Cholesterol; Chorioallantoic Membrane; Chrysanthemum; Endothelial Cells; Fibroblast Growth Factor 2; Humans; Phytosterols

Phytosterols (PS) are naturally occurring compounds present in food products of plant origin. Due to reported positive health effects, some food products are also enriched with PS. In the same way as cholesterol is oxidised, PS also oxidise to a variety of oxidation products (POPs). The biological effects and safety aspects of POPs are still unclear. This study investigated whether POPs are genotoxic in vivo, using a flow cytometer-based micronucleus assay in mice. The highest dose of oxidation products administered was 67mg/kg b.w. for epoxides and 9.4mg/kg b.w. for triols. Synthesised and separated triols and epoxides from a mixture of sitosterol and campesterol were investigated. The frequency of micronucleated polychromatic erythrocytes (fMNPCE) in POP-exposed mice did not significantly differ from the control values in either of two experiments performed. The flow cytometer-based method also allows for restriction of the analysis to micronuclei with a high DNA content, indicating an aneugenic potency. Even with this approach, there was no significant increase in the frequency of micronucleated erythrocytes among POP-treated mice compared with control mice. Furthermore, no significant deviation in cell proliferation rate (%PCE) was observed.

Topics: Animals; Cell Proliferation; Cholesterol; Dose-Response Relationship, Drug; Epoxy Compounds; Erythrocytes; Flow Cytometry; Male; Mice; Mice, Inbred CBA; Micronuclei, Chromosome-Defective; Micronucleus Tests; Mutagens; Oxidation-Reduction; Phytosterols; Sitosterols

To investigate lipid components of high-yielded Pinellia ternata rhizomes growing in the west of Hubei province.. To determine the lipid chemical components in Pinellia ternata rhizomes with GC-MS method and NIST atlas.. Ten components have been found: palmitic acid (I), 9,12-octadecadienoic acid (II), pyrrolidine,1-(1-oxo-7,10-hexadecadienyl) (III), alpha-monpalmitin (IV), 1,3,12-nonadecatriene (V), campesterol (VI), stigmasta-5,22-dien-3-ol (VII), beta-sitosterol (VIII), stigmasta-5,24-dien-3-ol (IX), cycloartenol (X).. The relative contents of five kinds of phytosterol: campesterol 28.96%, stigmasta-5,22-dien-3-ol 9.24%, beta-sitosterol 50.77%, stigmasta-5,24-dien-3-ol 4.74%, cycloartenol 6.25%. Component II, III, V, VI, IX are the first time reported in Pinellia ternata.

Topics: China; Cholesterol; Gas Chromatography-Mass Spectrometry; Linoleic Acid; Palmitic Acid; Phytosterols; Pinellia; Plant Tubers; Plants, Medicinal; Sitosterols; Stigmasterol

Feeding of chemically synthesized [27-13C]codisterol ([27-13C]2), [27-13C]24-epicodisterol ([27-13C]3), [23,24-2H2]codisterol ([23,24-2H2]2), and [26,27-2H6]24-methyldesmosterol ([26,27-2H6]8) to Oryza sativa cell cultures, followed by MS and NMR analysis of the biosynthesized dihydrobrassicasterol (9)/campesterol (10), revealed that both (24R)- and (24S)-epimers of 24-methyl-Delta25-cholesterol (2/3) were converted to 9 and 10 via the common intermediate 24-methyldesmosterol (8).

Topics: Cells, Cultured; Cholesterol; Magnetic Resonance Spectroscopy; Mass Spectrometry; Molecular Structure; Oryza; Phytosterols; Plants

ATP-binding cassette protein A1 (ABCA1) plays a major role in cholesterol homeostasis and high density lipoprotein metabolism. Apolipoprotein A-I binds to ABCA1 and cellular cholesterol and phospholipids, mainly phosphatidylcholine, are loaded onto apoA-I to form pre-beta high density lipoprotein (HDL). It is proposed that ABCA1 translocates phospholipids and cholesterol directly or indirectly to form pre-beta HDL. To explore the mechanism of ABCA1-mediated pre-beta HDL formation, we expressed human ABCA1 in insect Sf9 cells and purified it. Trypsin limited-digestion of purified ABCA1 in the detergent-soluble form suggested that it retained conformation similar to ABCA1 expressed in the membranes of human fibroblast WI-38 cells. Purified ABCA1 showed robust ATPase activity when reconstituted in liposomes made of synthetic phosphatidylcholine. ABCA1 showed lower ATPase activity when reconstituted in liposomes containing phosphatidylserine, phosphatidylethanolamine, or phosphatidylglycerol and also showed weak specificity in acyl chain species. ATPase activity was reduced by the addition of cholesterol and decreased by 25% in the presence of 20% cholesterol. Beta-sitosterol and campesterol showed similar inhibitory effects but stigmasterol did not, suggesting structure-specific interaction between ABCA1 and sterols. Glibenclamide suppressed ABCA1 ATPase, suggesting that it inhibits apoA-I-dependent cellular cholesterol efflux by suppressing ABCA1 ATPase activity. These results suggest that the ATPase activity of ABCA1 is stimulated preferentially by phospholipids with choline head groups, phosphatidylcholine and sphingomyelin. This study with purified human ABCA1 provides the first biochemical basis of the mechanism for HDL formation mediated by ABCA1.

Topics: Adenosine Triphosphatases; Animals; ATP Binding Cassette Transporter 1; ATP-Binding Cassette Transporters; Baculoviridae; Cell Line; Cell Membrane; Cholesterol; Choline; Chromatography, Ion Exchange; Detergents; DNA, Complementary; Dose-Response Relationship, Drug; Fibroblasts; Genetic Vectors; Glyburide; Glycosylation; Humans; Insecta; Intracellular Membranes; Lipids; Lipoproteins, HDL; Liposomes; Microsomes; Models, Biological; Phosphatidylcholines; Phosphatidylethanolamines; Phosphatidylglycerols; Phosphatidylserines; Phospholipids; Phytosterols; Protein Binding; Sepharose; Sitosterols; Time Factors; Trypsin

We previously showed that variant SLCO1B1 haplotype *1b (A388G) accelerates and that *5 (T521C) delays hepatocellular uptake of the HMG-CoA reductase inhibitor pravastatin [Mwinyi et al. (2004): Clin Pharmacol Ther 75:415-421]. In the present study we checked for differential effects of variant SLCO1B1 haplotypes on hepatocellular cholesterol synthesis. We analyzed the serum levels of cholesterol, lathosterol, and campesterol in healthy white males which had been grouped on the basis of their SLCO1B1 haplotype: *1a (n=10), *1b (n=10), and *5 (n=8). The subjects received a single oral dose of 40 mg pravastatin. Cholesterol and lathosterol levels were lower in all subjects following pravastatin intake for up to 24. Median levels 6 h post-dosing of lathosterol decreased in each SLCO1B1 haplotype group in the rank order of *1b (-0.11 mg dl(-1); min-max: -0.20 to -0.04; p=0.005) > *1a (-0.09 mg dl(-1); min-max: -0.22 to -0.05; p=0.005) > *5 (-0.07 mg dl(-1); min-max: -0.17 to -0.05; p=0.012). Lathosterol median-change values were significantly greater in haplotype *1b than in haplotype *5 individuals (p=0.041, non-adjusted), which was congruent with the extent of mean changes in lathosterol-to-cholesterol ratios, although the latter did not reach statistical significance. Post-treatment serum levels of campesterol were not affected by SLCO1B1 haplotype. Interestingly, sterol basal serum levels tended to be highest in *1b carriers, followed by those in *1a and *5 individuals, with significant differences in lathosterol concentrations between the *1b and *5 (p=0.041, non-adjusted) haplotype group. Our findings suggest an association of SLCO1B1*1b and *5 haplotypes to pravastatin's inhibition of the hepatocellular HMG-CoA reductase. Furthermore, SLCO1B1 haplotypes seem to play a role in basal cholesterol homeostasis.

Topics: Adult; Anticholesteremic Agents; Cholesterol; Haplotypes; Humans; Liver-Specific Organic Anion Transporter 1; Male; Middle Aged; Organic Anion Transporters; Phytosterols; Pravastatin

Dietary campest-5-en-3-one (campestenone), an oxidized derivative of campesterol, significantly reduced visceral fat weight and the concentration of triacylglycerol in serum and liver of rats. Dietary campestenone dramatically increased the activities and the mRNA expressions of mitochondrial and peroxisomal enzymes involved in beta-oxidation in the liver. Campestenone activated human peroxisome proliferator-activated receptor (PPAR) alpha as determined using the novel GAL4 ligand-binding domain chimera assay system with coactivator coexpression. In contrast, dietary campestenone reduced the activities and the mRNA expressions of enzymes involved in fatty acid synthesis, except for the malic enzyme. Dietary campestenone decreased the sterol regulatory element binding protein-1 (SREBP-1) mRNA level. Energy expenditure was significantly higher in the feeding of campestenone in rats. Dietary campestenone reduced hepatic cholesterol concentration and increased fecal excretion of neutral steroids originated from cholesterol. Lymphatic absorption of cholesterol was reduced by the coadministration of campestenone in rats cannulated in the thoracic duct. These observations suggest a possibility that campestenone has an ability to prevent coronary heart disease by improving obesity and abnormality of lipid metabolism.

Topics: Animals; Body Weight; Cholesterol; Energy Metabolism; Fatty Acids; Feces; Intra-Abdominal Fat; Liver; Male; Oxidation-Reduction; Oxidoreductases; Phytosterols; PPAR alpha; Rats; Rats, Inbred Strains; RNA, Messenger; Steroids; Sterol Regulatory Element Binding Protein 1

Trifolium balansae (Leguminosae) yielded a phytylester, phytyl-1-hexanoate, three steroids, stigmast-5-ene-3 beta,26-diol, stigmast-5-ene-3-ol and campesterol, and an alcohol, pentacosanol which were reported for the first time from T.balansae. The structures of the isolates were determined by 1D and 2D NMR techniques and MS spectroscopy. Compounds 1-5 were tested for their enzyme tyrosinase activity. While compounds 1 and 5 did not show any inhibition against the enzyme tyrosinase, compounds 2, 3, and 4 exhibited potent inhibition against tyrosinase. Highly potent (IC50 = 2.39 microM) inhibition was found by compound 2, when compared with the standard tyrosinase inhibitors Kojic acid and L-mimosine.

Topics: Cholesterol; Enzyme Inhibitors; Inhibitory Concentration 50; Molecular Structure; Monophenol Monooxygenase; Nuclear Magnetic Resonance, Biomolecular; Phytosterols; Plant Extracts; Spectrometry, Mass, Electrospray Ionization; Spectrophotometry, Infrared; Stigmasterol; Trifolium

Intestinal absorption of various plant sterols was investigated in thoracic duct-cannulated normal rats. Lymphatic recovery was the highest in campesterol, intermediate in brassicasterol and sitosterol, and the lowest in stigmasterol and sitostanol. Higher solubility in the bile salt micelle was observed in sitosterol, campesterol, and sitostanol than in brassicasterol and stigmasterol. The solubility of the latter two sterols was extremely low. When the affinity of plant sterols for the bile salt micelle was compared in an in vitro model system, which assessed sterol transfer from the micellar to the oil phase, the transfer rate was the highest in brassicasterol, intermediate in campesterol and stigmasterol, and lowest in sitosterol and sitostanol. Although no significant correlations between lymphatic recovery of plant sterols and their micellar solubility or transfer rate from the bile salt micelle were observed, highly positive correlation was obtained between the lymphatic recovery and the multiplication value of the micellar solubility and the transfer rate. These observations strongly suggest that both solubility in and affinity for the bile salt micelle of plant sterols are important determinants of their intestinal absorption in rats.

Topics: Animals; Bile Acids and Salts; Cholestadienols; Cholesterol; Intestinal Absorption; Lymph; Male; Micelles; Models, Biological; Phytosterols; Rats; Rats, Wistar; Sitosterols; Solubility; Stigmasterol; Triolein

A novel analytical platform based on liquid chromatography and tandem mass spectrometry using atmospheric pressure photoionization was applied for the simultaneous quantification of free and esterified beta-sitosterol, campesterol, brassicasterol, and stigmasterol. The total time for sample pretreatment and analysis could be reduced from approximately 3 h [gas chromatography-mass spectrometry (GC-MS)] to 15 min. The detection limits of the different phytosterols ranged between 0.25 and 0.68 microg/l. Linear ranges were between 1 and 1,000 microg/l. The within-run and between-run variabilities ranged between 1.4% and 9.9%. The analytical sensitivity was at least 150-fold higher compared with GC-MS. Our new method allows a rapid and simultaneous determination of free and esterified phytosterols in serum.

Topics: Cholestadienols; Cholesterol; Chromatography, Liquid; Esters; Humans; Mass Spectrometry; Methods; Phytosterols; Reproducibility of Results; Sitosterols; Stigmasterol

Polymorphisms in the ATP binding cassette (ABC) transporters ABCG5 and ABCG8 are related to plasma plant sterol concentrations. It is not known whether these polymorphisms are also associated with variations in serum plant sterol concentrations during interventions affecting plant sterol metabolism. We therefore decided to study changes in serum plant sterol concentrations with ABCG5/G8 polymorphisms after consumption of plant stanol esters, which decrease plasma plant sterol concentrations. Cholesterol-standardized serum campesterol and sitosterol concentrations were significantly associated with the ABCG8 T400K genotype, as were changes in serum plant sterol concentrations after consumption of plant stanols. The reduction of -57.1 +/- 38.3 10(2) x micromol/mmol cholesterol for sitosterol in TT subjects was significantly greater compared with the -36.0 +/- 18.7 reduction in subjects with the TK genotype (P = 0.021) and the -16.9 +/- 13.0 reduction in subjects with the KK genotype (P = 0.047). Changes in serum campesterol concentrations showed a comparable association. No association with serum LDL cholesterol was found. Genetic variation in ABCG8 not only explains cross-sectional differences in serum plant sterol concentrations but also determines a subject's responsiveness to changes in serum plant sterols during interventions known to affect plant sterol metabolism.

Topics: Adolescent; Adult; ATP Binding Cassette Transporter, Subfamily G, Member 8; ATP-Binding Cassette Transporters; Cholesterol; Diet; Energy Metabolism; Female; Genotype; Humans; Lipids; Lipoproteins; Male; Middle Aged; Phytosterols; Polymorphism, Genetic; Sitosterols

Serum cholesterol reflects poorly cholesterol metabolism. From serum noncholesterol sterols cholestanol, campesterol, and sitosterol are surrogate markers of cholesterol absorption, but reflect also cholestasis, while those of lathosterol reflect cholesterol synthesis and hepatic parenchymal function. We investigated these sterols at end-stage of primary biliary cirrhosis (PBC) - prior to liver transplantation and shortly after transplantation in 67 patients to show their role as index of cholestasis and parenchymal liver function. Median preoperative values of cholestanol were increased 7.6 times, those of plant sterols 1.6-3.7 times above and the campesterol/sitosterol ratio was decreased twice below our control values, respective lathosterol levels being mainly subnormal. After transplantation, the proportions to cholesterol of the absorption markers decreased, and those of synthesis markers and the ratios of campesterol/sitosterol increased significantly. Thus, surrogate sterol markers of cholesterol absorption and synthesis in serum are also good clinical markers of chronic cholestasis and degree of hepatic parenchymal cell function in PBC. Postoperative improvement of serum sterol profile indicate clinically good function of the liver graft.

Topics: Adult; Aged; Bilirubin; Biomarkers; Cholestanol; Cholesterol; Female; Humans; Liver Cirrhosis, Biliary; Liver Function Tests; Liver Transplantation; Male; Middle Aged; Phytosterols; Sitosterols; Sterols

Seven new glycosides of the campesterol derivative (24R,25S)-ergost-5-ene-3beta,26-diol (1-7) were isolated from the rhizomes of Tacca chantrieri (Taccaceae). Their structures were determined by extensive spectroscopic analysis, including 2D NMR data, and a few chemical transformations.

Topics: Cholesterol; Dioscoreaceae; Drugs, Chinese Herbal; Glycosides; Hydrolysis; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Phytosterols; Plant Extracts; Rhizome

The ATP binding cassette transporters ABCG5 (G5) and ABCG8 (G8) limit the accumulation of neutral sterols by restricting sterol uptake from the intestine and promoting sterol excretion into bile. Humans and mice lacking G5 and G8 (G5G8-/-) accumulate plant sterols in the blood and tissues. However, despite impaired biliary cholesterol secretion, plasma and liver cholesterol levels are lower in G5G8-/- mice than in wild-type littermates. To determine whether the observed changes in hepatic sterol metabolism were a direct result of decreased biliary sterol secretion or a metabolic consequence of the accumulation of dietary noncholesterol sterols, we treated G5G8-/- mice with ezetimibe, a drug that reduces the absorption of both plant- and animal-derived sterols. Ezetimibe feeding for 1 month sharply decreased sterol absorption and plasma levels of sitosterol and campesterol but increased cholesterol in both the plasma (from 60.4 to 75.2 mg/dl) and the liver (from 1.1 to 1.87 mg/g) of the ezetimibe-treated G5G8-/- mice. Paradoxically, the increase in hepatic cholesterol was associated with an increase in mRNA levels of HMG-CoA reductase and synthase. Together, these results indicate that pharmacological blockade of sterol absorption can ameliorate the deleterious metabolic effects of plant sterols even in the absence of G5 and G8.

Topics: Absorption; Animals; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; ATP-Binding Cassette Transporters; Azetidines; Cholesterol; Ezetimibe; Lipoproteins; Liver; Mice; Mice, Knockout; Phytosterols; Sitosterols; Sterols

The purpose of this research was to determine whether serum plant sterol levels are associated with those in atheromatous plaque.. Cholesterol of low-density lipoprotein (LDL) particles contributes to atheromatous plaque formation; LDL also contains most serum non-cholesterol sterols, including plant sterols. The role of plant sterols in atheromatous plaque formation is open.. Free, ester, and total cholesterol and the respective non-cholesterol sterols were measured by gas-liquid chromatography in serum and arterial tissue of 25 consecutive patients undergoing carotid endarterectomy. The population was ranked to triads according to tissue cholesterol concentration.. Cholesterol concentration increased markedly in tissues but not in serum with triads. The ester percentage was lower in the third than in the first triad (47% vs. 56%; p < 0.01) and lower than in serum triads (70%; p < 0.001). Ratios to cholesterol of non-cholesterol sterols decreased in increasing tissue triads, but were unchanged in serum. A major new observation was that the higher the ratio to cholesterol of the surrogate absorption sterols (cholestanol, campesterol, sitosterol, and avenasterol) in serum, the higher was their ratio also in the carotid artery wall (e.g., r = 0.683 for campesterol). Despite undetectable differences in serum and tissue cholesterol concentrations off and on statins, an additional important novel finding was that statin treatment was associated with increased ratios of the absorption sterols in serum and also in the arterial plaque.. The higher the absorption of cholesterol, the higher are the plant sterol contents in serum resulting also in their higher contents in atherosclerotic plaque. However, the role of dietary plant sterols in the development of atherosclerotic plaque is not known.

Topics: Absorption; Aged; Aged, 80 and over; Carotid Arteries; Carotid Artery Diseases; Cholestanol; Cholesterol; Cholesterol, HDL; Chromatography, Gas; Endarterectomy, Carotid; Female; Humans; Middle Aged; Phytosterols; Sitosterols

We have identified a rice (Oryza sativa) brassinosteroid (BR)-deficient mutant, BR-deficient dwarf2 (brd2). The brd2 locus contains a single base deletion in the coding region of Dim/dwf1, a homolog of Arabidopsis thaliana DIMINUTO/DWARF1 (DIM/DWF1). Introduction of the wild-type Dim/dwf1 gene into brd2 restored the normal phenotype. Overproduction and repression of Dim/dwf1 resulted in contrasting phenotypes, with repressors mimicking the brd2 phenotype and overproducers having large stature with increased numbers of flowers and seeds. Although brd2 contains low levels of common 6-oxo-type BRs, the severity of the brd2 phenotype is much milder than brd1 mutants and most similar to d2 and d11, which show a semidwarf phenotype at the young seedling stage. Quantitative analysis suggested that in brd2, the 24-methylene BR biosynthesis pathway is activated and the uncommon BR, dolichosterone (DS), is produced. DS enhances the rice lamina joint bending angle, rescues the brd1 dwarf phenotype, and inhibits root elongation, indicating that DS is a bioactive BR in rice. Based on these observations, we discuss an alternative BR biosynthetic pathway that produces DS when Dim/dwf1 is defective.

Topics: Amino Acid Sequence; Arabidopsis; Arabidopsis Proteins; Cholesterol; Exons; Flowers; Gene Deletion; Molecular Sequence Data; Mutation; Oryza; Phenotype; Phytosterols; Seeds

Previous studies from our laboratory on tumor cells suggest that phytosterols stimulate ceramide production, which was associated with cell growth inhibition and stimulation of apoptosis. The objective of the present study was to examine the effect of phytosterols on ceramide metabolism in small intestinal cells that represent the first cells in contact with dietary phytosterols. Caco(2) cells, an accepted model for human intestinal epithelial cells, were used in this study. Ceramide and ceramide-containing lipids were examined by labeling the ceramide pool with (3)H-serine. Cells were supplemented with 16 microM of sterols (cholesterol, beta-sitosterol or campesterol) for 16 days postconfluence and continued to differentiate. Of the two phytosterols, beta-sitosterol, but not campesterol, induced more than double the serine labeling when compared with cholesterol. This increase was uniform in sphingomyelin (SM), ceramide and sphingosine labeling. Sterols had no effect on SM concentration in the cells. In addition, sterol had no effect on the activity of SM synthase or sphingomyelinases. There was an inhibition of ceramidases with campesterol supplementation. These data suggest that the observed increases in SM and sphingosine labeling were due to an increase in ceramide turnover. The increase in ceramide turnover with beta-sitosterol supplementation was not associated with growth inhibition but was with increases in ceramide glycosylation products such as cerebrosides and gangliosides. It was concluded that beta-sitosterol has no effect on differential Caco(2), a model of normal small intestinal cells. The increase in the glycosylated ceramide products may offer a means to protect the cells from the harmful effect of ceramide by excreting them with lipoproteins.

Topics: Caco-2 Cells; Cell Differentiation; Cell Division; Ceramides; Cholesterol; Enterocytes; Humans; Phytosterols; Sitosterols; Sphingomyelins; Sphingosine

Several studies in humans have demonstrated the hypocholesterolemic effect of plant sterol consumption. It is unclear whether plant sterols regulate lipoprotein metabolism in the liver and intestines, thereby decreasing the levels of circulating atherogenic lipoproteins. We investigated the effect of the three main phytosterols: stigmasterol, campesterol, and beta-sitosterol on lipoprotein production in HepG2 human liver cells and Caco2 human intestinal cells and the mechanisms involved. Cells were incubated for 24h with 50 micromol/L of the different phytosterols or 10 micromol/L of atorvastatin. Very low-density lipoprotein levels (measured by apolipoprotein (apo) B100) in HepG2 cells and chylomicron levels (measured by apoB48) in Caco2 cells were measured using western blotting. Intracellular cholesterol levels were measured using gas chromatography. Analysis was carried out using Student's t-test and ANOVA. Secretion levels of apoB100 significantly decreased by approximately 30% after incubation with all phytosterols compared to control. In addition, cholesterol ester (CE) concentrations significantly decreased when HepG2 cells were incubated with the phytosterols compared to control cells. Secretion of apoB48 from intestinal cells significantly decreased by 15% with stigmasterol, 16% with campesterol and 19% beta-sitosterol compared to control. Collectively the data suggests that plant sterols limit lipid (CE) availability in cells. Decreases in circulating levels of LDL and chylomicron remnants seen in humans with the consumption of margarine phytosterols are possibly due to their effect on lipid production in cells and would therefore reduce the risk of developing cardiovascular disease.

Topics: Anticholesteremic Agents; Apolipoprotein B-100; Apolipoprotein B-48; Apolipoproteins B; Atherosclerosis; Atorvastatin; Caco-2 Cells; Carcinoma, Hepatocellular; Cholesterol; Drug Synergism; Enterocytes; Hepatocytes; Heptanoic Acids; Humans; Liver Neoplasms; Margarine; Phytosterols; Pyrroles; Sitosterols; Stigmasterol

The content of phytosterol oxidation products (POPs) in enriched and nonenriched commercial spreads was evaluated by thin-layer chromatography-gas chromatography (TLC-GC). Oxides of beta-sitosterol, campesterol, and stigmasterol were produced by thermo-oxidation (7-hydroxy, 7-keto, and epoxy derivatives) and chemical synthesis (triol derivatives), which were then separated and identified by TLC-GC. Their identification was further confirmed by GC-mass spectrometry (GC-MS). The total amounts of phytosterols found were 6.07 and 0.33 g/100 g of sample in phytosterol-enriched and nonenriched spread, respectively, whereas the total POPs contents were 45.60 and 13.31 mg/kg of sample in the enriched and nonenriched products. The main POPs found were the 7-keto derivatives of all phytosterols analyzed; 7-ketositosterol was the most abundant one (14.96 and 5.93 mg/kg of sample in phytosterol-enriched and nonenriched spread). No beta-epoxy and triol derivatives were detected in both types of samples. The enriched spread presented a lower phytosterol oxidation rate (0.07%) than the nonenriched one (0.41%).

Topics: Cholesterol; Chromatography, Gas; Chromatography, Thin Layer; Food Analysis; Food, Fortified; Margarine; Oxidation-Reduction; Oxides; Phytosterols; Sitosterols; Stigmasterol

The structural features of sterols required to support mammalian cell growth have not been fully defined. Here, we use mutant CHO cells that synthesize only small amounts of cholesterol to test the capacity of various sterols to support growth. Sterols with minor modifications of the side chain (e.g., campesterol, beta-sitosterol, and desmosterol) supported long-term growth of mutant cells, but sterols with more complex modifications of the side chain, the sterol nucleus, or the 3-hydroxy group did not. After 60 days in culture, the exogenous sterol comprised >90% of cellular sterols. Inactivation of residual endogenous synthesis with the squalene epoxidase inhibitor NB-598 prevented growth in beta-sitosterol and greatly reduced growth in campesterol. Growth of cells cultured in beta-sitosterol and NB-598 was restored by adding small amounts of cholesterol to the medium. Surprisingly, enantiomeric cholesterol also supported cell growth, even in the presence of NB-598. Thus, sterols fulfill two roles in mammalian cells: (i) a bulk membrane requirement in which phytosterols can substitute for cholesterol and (ii) other processes that specifically require small amounts of cholesterol but are not enantioselective.

Topics: Animals; Benzylamines; Cell Proliferation; CHO Cells; Cholesterol; Cricetinae; Cricetulus; Phytosterols; Sitosterols; Thiophenes

Type I diabetes is associated with altered hepatic bile formation and increased intestinal cholesterol absorption. The aim of this study was to evaluate whether altered expression of the ATP-Binding Cassette half-transporters Abcg5 and Abcg8, recently implicated in control of both hepatobiliary cholesterol secretion and intestinal cholesterol absorption, contributes to changed cholesterol metabolism in experimental diabetes.. mRNA and protein expression of Abcg5 and Abcg8 were determined in the liver and intestine of rats with streptozotozin-induced diabetes and related to relevant metabolic parameters in plasma, liver and bile.. Hepatic mRNA expression of both Abcg5 (-76%) and Abcg8 (-71%) was reduced in diabetic rats when compared to control rats. In spite of increased HDL cholesterol, considered a major source of biliary cholesterol, secretion of the sterol into bile relative to that of bile salts was reduced by 65% in diabetic animals. Intestinal mRNA expression of Abcg5 (-47%) and Abcg8 (-43%) as well as Abcg5 protein contents were also reduced in insulin-deficient animals. This was accompanied by a three- to four-fold increase in plasma beta-sitosterol and campesterol concentrations and by a doubling of the calculated apparent cholesterol absorption. These effects partially normalized upon insulin supplementation.. Our data indicate that effects of insulin-deficiency on bile composition and cholesterol absorption in rats are, at least partly, attributable to changes in hepatic and intestinal Abcg5 and Abcg8 expression.

Topics: Animals; Apolipoprotein A-I; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; ATP-Binding Cassette Transporters; Bile; Cholesterol; Diabetes Mellitus, Experimental; Gene Expression Regulation; Intestinal Mucosa; Lipoproteins; Liver; Male; Phytosterols; Rats; Rats, Wistar; RNA, Messenger; Sitosterols; Transcription, Genetic; Triglycerides

Mutations in either adenosine triphosphate- binding cassette (ABC) half-transporter G5 or G8 cause sitosterolemia. It has been proposed that ABCG5/ABCG8 heterodimers mediate secretion of plant sterols and cholesterol by hepatocytes into bile and their efflux from enterocytes into the intestinal lumen.. To test whether deficiency of ABCG5 alone is sufficient to induce sitosterolemia, Abcg5-null mice were generated and characterized with respect to sterol metabolism.. Abcg5 deficiency was associated with strongly elevated plasma levels of beta-sitosterol (37-fold) and campesterol (7.7-fold) as well as reduced plasma cholesterol concentrations (-40%). Retention of orally administered [(3)H]beta-sitosterol in the intestinal wall (+550%) and plasma (+640%) was higher in Abcg5-null mice than in wild-type controls. Surprisingly, high plasma beta-sitosterol and campesterol concentrations were even further elevated in Abcg5-null mice on treatment with the synthetic LXR agonist T0901317 (0.015% dietary supplementation, 10 days), whereas these concentrations were reduced by approximately 75% in wild-type mice. Both cholesterol and phospholipid concentrations in gallbladder bile were decreased, but, unexpectedly, cholesterol/phospholipid ratios were unchanged in the absence of Abcg5 and increased in both genotypes on LXR activation. Hepatic expression of Abcg8 was reduced by about 35% in Abcg5-deficient mice when compared with controls. No compensatory overexpression of other ABC transporters potentially involved in hepatic cholesterol trafficking was observed on messenger RNA level.. Our data show that disruption of the Abcg5 gene alone is sufficient to cause hyperabsorption of dietary plant sterols and sitosterolemia in mice, whereas the ability to secrete cholesterol into bile is maintained.

Topics: Animals; Anticholesteremic Agents; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP-Binding Cassette Transporters; Bile; Bile Acids and Salts; Cholesterol; DNA-Binding Proteins; Gallbladder; Genotype; Hydrocarbons, Fluorinated; Lipoproteins; Liver X Receptors; Mice; Mice, Knockout; Orphan Nuclear Receptors; Phospholipids; Phytosterols; Receptors, Cytoplasmic and Nuclear; Sitosterols; Sulfonamides

Mutations in either of two genes comprising the STSL locus, ATP-binding cassette (ABC)-transporters ABCG5 (encoding sterolin-1) and ABCG8 (encoding sterolin-2), result in sitosterolemia, a rare autosomal recessive disorder of sterol trafficking characterized by increased plasma plant sterol levels. Based upon the genetics of sitosterolemia, ABCG5/sterolin-1 and ABCG8/sterolin-2 are hypothesized to function as obligate heterodimers. No phenotypic difference has yet been described in humans with complete defects in either ABCG5 or ABCG8. These proteins, based upon the defects in humans, are responsible for regulating dietary sterol entry and biliary sterol secretion.. In order to mimic the human disease, we created, by a targeted disruption, a mouse model of sitosterolemia resulting in Abcg8/sterolin-2 deficiency alone. Homozygous knockout mice are viable and exhibit sitosterolemia.. Mice deficient in Abcg8 have significantly increased plasma and tissue plant sterol levels (sitosterol and campesterol) consistent with sitosterolemia. Interestingly, Abcg5/sterolin-1 was expressed in both liver and intestine in Abcg8/sterolin-2 deficient mice and continued to show an apical expression. Remarkably, Abcg8 deficient mice had an impaired ability to secrete cholesterol into bile, but still maintained the ability to secrete sitosterol. We also report an intermediate phenotype in the heterozygous Abcg8+/- mice that are not sitosterolemic, but have a decreased level of biliary sterol secretion relative to wild-type mice.. These data indicate that Abcg8/sterolin-2 is necessary for biliary sterol secretion and that loss of Abcg8/sterolin-2 has a more profound effect upon biliary cholesterol secretion than sitosterol. Since biliary sitosterol secretion is preserved, although not elevated in the sitosterolemic mice, this observation suggests that mechanisms other than by Abcg8/sterolin-2 may be responsible for its secretion into bile.

Topics: Animals; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; ATP-Binding Cassette Transporters; Bile; Bile Acids and Salts; Cholesterol; Female; Gene Expression; Intestines; Lipoproteins; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Models, Animal; Mutation; Phytosterols; Sitosterols

We studied the concentrations and ratios to cholesterol of noncholesterol sterols reflecting absorption (eg, campesterol) or synthesis (eg, lathosterol) of cholesterol off and on plant sterol and stanol ester spreads in serum and in different lipoproteins of a family with familial hypercholesterolemia, including heterozygous parents receiving no treatment and their homozygous offspring undergoing long-term treatment with statins and apheresis. Serum cholesterol levels were similar in the homozygous and heterozygous individuals, but the concentrations of sterols reflecting cholesterol absorption were as much as 10 times greater in the homozygous child than in the heterozygous parents, whereas the respective markers of cholesterol synthesis only tended to be higher. About 70% of squalene in the homozygous individual (60% in the heterozygous family members) and 85% to 90% of noncholesterol sterols (60%-80% in the heterozygous subjects) were transported by low-density lipoprotein. The ratios of absorption sterols to cholesterol were higher in high-density lipoprotein (HDL) than in very low-density lipoprotein (VLDL), whereas those of synthesis markers and plant stanols were highest in VLDL. The ratios of absorption sterols in serum were mostly lower than those in HDL but higher than in VLDL, whereas the ratios of synthesis sterols in serum were lower than they were in VLDL. Both spreads reduced serum total cholesterol by about 14% in the heterozygous family members and 9% in the homozygous individual. The sterol ester spread increased serum plant sterol concentrations (eg, campesterol in the homozygous family member increased from 5 to 9 mg/dL) and the ratios to cholesterol, but the stanol ester spread decreased them. Plant sterol esters seemed to similarly decrease serum cholesterol in this family with familial hypercholesterolemia, but the clinical role of increased plant sterol concentrations, almost doubled in the LDL of homozygous individuals, is not known.

Topics: Adult; Blood Component Removal; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Dietary Fats; Double-Blind Method; Female; Heterozygote; Homozygote; Humans; Hyperlipoproteinemia Type II; Hypolipidemic Agents; Male; Margarine; Middle Aged; Phytosterols; Sitosterols; Squalene; Triglycerides

Clinical studies have demonstrated that consumption of phytosterol esters in lipid-based foods decreases serum concentrations of total and LDL cholesterol. These substances represent minimal potential for adverse effects when consumed orally because of their low bioavailability. However, some studies have reported estrogenic and other effects in laboratory animals treated parenterally with phytosterols, demonstrating that these substances may have the potential to cause adverse effects if absorbed. Water-soluble phytosterols have been prepared by formulation with emulsifiers to expand delivery options to include non-lipid-based foods. However, emulsifiers are used as excipients in the formulation of lipophilic pharmaceuticals to increase solubility, thereby increasing their absorption. Therefore, oral consumption of emulsified water-soluble phytosterols could potentially increase their absorption. In the current study, absorption of phytosterols prepared as water-soluble emulsified micelles with two different food-grade emulsifiers was evaluated in Sprague-Dawley rats and compared with absorption of non-micellar free phytosterols and esterified phytosterol mixtures dissolved in a lipophilic vehicle (soybean oil). Rats were dosed via gavage with 42 mg/kg of formulated phytosterol preparations. Blood was collected at 8, 16, 24, and 32 hours, extracted with hexane, derivatized with benzoyl chloride, and analyzed by high-performance liquid chromatography to determine concentrations of beta-sitosterol, and campesterol. Plasma concentrations and AUC(0-32 hours) [microg/mL/h] of beta-sitosterol and campesterol were lower in plasma obtained from rats treated with emulsified phytosterol preparations than in animals treated with free phytosterols dissolved in soybean oil. Because the pharmacokinetic profile of water-soluble phytosterols is similar to that of phytosterols administered in a lipid vehicle, the safety profile is likely to be the same as that of phytosterols and phytosterol esters in currently used applications.

Topics: Absorption; Animals; Cholesterol; Chromatography, High Pressure Liquid; Diet; Emulsions; Esterification; Kinetics; Micelles; Mouth; Phosphatidylcholines; Phytosterols; Rats; Rats, Sprague-Dawley; Sitosterols; Solubility; Water

A large body of evidence from the past decade supports the existence of functional microdomains in membranes of animal and yeast cells, which play important roles in protein sorting, signal transduction, or infection by pathogens. They are based on the dynamic clustering of sphingolipids and cholesterol or ergosterol and are characterized by their insolubility, at low temperature, in nonionic detergents. Here we show that similar microdomains also exist in plant plasma membrane isolated from both tobacco leaves and BY2 cells. Tobacco lipid rafts were found to be greatly enriched in a sphingolipid, identified as glycosylceramide, as well as in a mixture of stigmasterol, sitosterol, 24-methylcholesterol, and cholesterol. Phospho- and glycoglycerolipids of the plasma membrane were largely excluded from lipid rafts. Membrane proteins were separated by one- and two-dimensional gel electrophoresis and identified by tandem mass spectrometry or use of specific antibody. The data clearly indicate that tobacco microdomains are able to recruit a specific set of the plasma membrane proteins and exclude others. We demonstrate the recruitment of the NADPH oxidase after elicitation by cryptogein and the presence of the small G protein NtRac5, a negative regulator of NADPH oxidase, in lipid rafts.

Topics: Blotting, Western; Cell Membrane; Centrifugation, Density Gradient; Cholesterol; Chromatography, High Pressure Liquid; Chromatography, Thin Layer; Detergents; Electrophoresis, Gel, Two-Dimensional; Electrophoresis, Polyacrylamide Gel; Ergosterol; Ions; Lipid Metabolism; Lipids; Mass Spectrometry; Membrane Microdomains; Microscopy, Electron; NADPH Oxidases; Nicotiana; Octoxynol; Phytosterols; Plant Leaves; Protein Structure, Tertiary; Signal Transduction; Sitosterols; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Stigmasterol; Sucrose; Temperature

Phytosterol oxidation products (oxyphytosterols) are formed during the processing and storage of foods. However, it is unknown whether oxyphytosterols affect human health. To address these issues, we prepared beta-sitosterol and campesterol oxides, evaluated their lymphatic absorption in rats, and examined the effect of an oxyphytosterol diet on atherosclerosis in apolipoprotein (apo) E-deficient mice. The lymphatic absorption of cholesterol and 6 oxyphytosterols (7alpha-hydroxy, 7beta-hydroxy, beta-epoxy, alpha-epoxy, dihydroxy, and 7-keto) of beta-sitosterol or campesterol was assessed in thoracic duct-cannulated rats fed an AIN-93G-based diet containing 2.5 g of cholesterol, oxyphytosterols, or intact phytosterols per kg. Lymphatic recoveries (on a mass basis) of oxycampesterols (15.9 +/- 2.8%, n = 10) and oxysitosterols (9.12 +/- 1.77%, n = 10) were higher than for campesterol (5.47 +/- 1.02%, n = 12, P < 0.05) and beta-sitosterol (2.16 +/- 0.37%, n = 12, P < 0.05), but lower than for cholesterol (37.3 +/- 8.3%, n = 6, P < 0.05). Apo E-deficient mice were fed an AIN-93G-based diet containing 0.2 g oxyphytosterols or intact phytosterols per kg for 9 wk. Diet-derived oxyphytosterols accumulated in the serum, liver, and aorta. Furthermore, the oxyphytosterol diet increased oxycholesterol in the serum compared to the phytosterol diet. However, there was no significant difference between the 2 groups in the serum and aortic cholesterol concentration, the lesion area in the aortic root, or 8-iso-prostaglandin F2alpha concentration in the urine. These results indicate that exogenous oxyphytosterols are well-absorbed and accumulate in the body, but do not promote the development of atherosclerosis in apo E-deficient mice.

Topics: Animals; Apolipoproteins E; Arteriosclerosis; Cholesterol; Intestinal Absorption; Lymphatic System; Male; Mice; Oxidation-Reduction; Phytosterols; Rats; Rats, Sprague-Dawley; Sitosterols; Tissue Distribution

The endogenous brassinosteroids in the dwarf mutant lk of pea (Pisum sativum) were quantified by gas chromatography-selected ion monitoring. The levels of castasterone, 6-deoxocastasterone, and 6-deoxotyphasterol in lk shoots were reduced 4-, 70-, and 6-fold, respectively, compared with those of the wild type. The fact that the application of brassinolide restored the growth of the mutant indicated that the dwarf mutant lk is brassinosteroid deficient. Gas chromatography-selected ion monitoring analysis of the endogenous sterols in lk shoots revealed that the levels of campestanol and sitostanol were reduced 160- and 10-fold, respectively, compared with those of wild-type plants. These data, along with metabolic studies, showed that the lk mutant has a defect in the conversion of campest-4-en-3-one to 5alpha-campestan-3-one, which is a key hydrogenation step in the synthesis of campestanol from campesterol. This defect is the same as that found in the Arabidopsis det2 mutant and the Ipomoea nil kbt mutant. The pea gene homologous to the DET2 gene, PsDET2, was cloned, and it was found that the lk mutation would result in a putative truncated PsDET2 protein. Thus it was concluded that the short stature of the lk mutant is due to a defect in the steroidal 5alpha-reductase gene. This defect was also observed in the callus induced from the lk mutant. Biosynthetic pathways involved in the conversion of campesterol to campestanol are discussed in detail.

Topics: 3-Oxo-5-alpha-Steroid 4-Dehydrogenase; Amino Acid Sequence; Brassinosteroids; Cholestanols; Cholesterol; Conserved Sequence; Dwarfism; Gene Expression Regulation, Plant; Molecular Sequence Data; Mutation; Phytosterols; Pisum sativum; Plant Diseases; Sequence Alignment; Sequence Deletion; Sequence Homology, Amino Acid; Sitosterols; Steroids, Heterocyclic

Small bowel transplantation impairs enteric function and causes malabsorption of cholesterol and bile acids. Growth hormone stimulates intestinal absorptive function. The authors hypothesized that long-term growth hormone therapy could improve absorption of bile acids and cholesterol after autotransplantation of the jejunoileum.. Sixteen pigs with similar food, cholesterol, and fat intake underwent either sham laparotomy or a model of jejunoileal autotransplantation, including extrinsic autonomic denervation, lymphatic interruption, and in situ cold ischemia. Five randomly chosen autotransplanted animals received daily growth hormone treatment for 8 weeks. Serum lipids, absorption, and excretion of cholesterol, bile acids, and fat were determined after 8 weeks. Mucosal morphometrics, proliferation, and enzyme activities were determined. Plasma cholesterol precursors and plant sterols, respective markers of cholesterol synthesis and absorption, were measured after 2 and 8 weeks.. After jejunoileal autotransplantation, growth hormone treatment significantly increased body weight gain, cholesterol absorption efficiency from 45.1% to 62.1%, plasma campesterol to cholesterol proportions, and biliary secretion of cholesterol. With or without growth hormone treatment, autotransplantation significantly increased fecal bile acid excretion, plasma cholesterol precursors, fecal bacterially modified neutral sterols, mucosal thickness of the ileum (but not jejunum), and intestinal transit time when compared with sham-operated animals. Crypt cell proliferation, mucosal enzyme activities, and microvilli showed no differences between the groups.. These findings suggest that growth hormone treatment selectively improves cholesterol, but not bile acid absorption, after autotransplantation of the jejunoileum.

Topics: Animals; Autonomic Denervation; Bile Acids and Salts; Cholesterol; Cholesterol, Dietary; Drug Evaluation, Preclinical; Feces; Female; Human Growth Hormone; Ileum; Intestinal Absorption; Intestinal Mucosa; Jejunum; Laparotomy; Lipids; Malabsorption Syndromes; Phytosterols; Postoperative Complications; Recombinant Proteins; Sitosterols; Sus scrofa; Transplantation, Autologous

The ABC transporters ABCG5 and ABCG8 limit absorption and promote excretion of dietary plant sterols. It is not known why plant sterols are so assiduously excluded from the body. Here we show that accumulation of plant sterols in mice lacking ABCG5 and ABCG8 (G5G8-/- mice) profoundly perturbs cholesterol homeostasis in the adrenal gland. The adrenal glands of the G5G8-/- mice were grossly abnormal in appearance (brown, not white) due to a 91% reduction in cholesterol content. Despite the very low cholesterol levels, there was no compensatory increase in cholesterol synthesis or in lipoprotein receptor expression. Moreover, levels of ABCA1, which mediates sterol efflux, were increased 10-fold in the G5G8-/- adrenals. Adrenal cholesterol levels returned to near-normal levels in mice treated with ezetimibe, which blocks phytosterol absorption. To determine which plant sterol(s) caused the metabolic changes, we examined the effects of individual plant sterols on cholesterol metabolism in cultured adrenal cells. Addition of stigmasterol, but not sitosterol, inhibited SREBP-2 processing and reduced cholesterol synthesis. Stigmasterol also activated the liver X receptor in a cell-based reporter assay. These data indicate that selected dietary plant sterols disrupt cholesterol homeostasis by affecting two critical regulatory pathways of lipid metabolism.

Topics: Adrenal Cortex Hormones; Adrenal Glands; Animals; ATP Binding Cassette Transporter, Subfamily G; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP-Binding Cassette Transporters; Cholesterol; Homeostasis; Lipoproteins; Mice; Mice, Knockout; Phytosterols; Sitosterols

Epidemiological studies suggest that dietary phytosterols may offer protection form some types of cancer including breast cancer. In an attempt to investigate the mechanism by which phytosterols offer this protection, we investigated the effect of the two most common dietary phytosterols, beta-sitosterol and campesterol, on the mevalonate and MAP Kinase (MAPK) pathways in MDA-MB-231 cells. These pathways play a role in cell growth and apoptosis. MDA-MB-231 cell line was used in this study since it is a hormone-insensitive tumor cell line which represents the majority of advanced breast cancer cases. Cells grown in the presence of 16 microM beta-sitosterol or campesterol for 3 days exhibited a 70% and 6% reduction in cell growth, respectively, while cholesterol treatment had no effect on growth as compared to the control. Studies investigating the effect of sterol supplementation on the relative and total sterol composition of cells, showed that cells supplemented with cholesterol contained 23% more cholesterol than the control. Cells supplemented with campesterol had almost one-half the cholesterol of controls but accumulated campesterol to account for 40% of the total sterols. In the case of cells supplemented with beta-sitosterol, cells had only 25% of their sterols as cholesterol and the rest was in the form of beta-sitosterol. All sterols tested equally inhibited de novo cholesterol synthesis using 14C-acetate as substrate. beta-Sitosterol supplemented cells had reduced cholesterol synthesis when using 3H-mevalonolactone as substrate, which suggests that the inhibition in this pathway is downstream of mevalonate where processes such as isoprenylation of proteins may take place. Mevalonate supplementation to cells treated with beta-sitosterol did not completely correct the observed growth inhibition by beta-sitosterol. There was no effect of sterols on the concentrations of both low (21-26 kDa) or high (44-74 kDa) molecular weight isoprenylated proteins in these cells. On the other hand, both the quantity and activity of MAPK was elevated in the cells supplemented with beta-sitosterol. These data suggest that the down regulation of cholesterol synthesis from mevalonate and stimulation of the MAPK pathway may play roles in the inhibition of MDA-MB-231 cell growth by beta-sitosterol.

Topics: Breast Neoplasms; Cell Division; Cholesterol; Humans; Mevalonic Acid; Mitogen-Activated Protein Kinases; Phytosterols; Protein Prenylation; Sitosterols; Tumor Cells, Cultured

The metabolic syndrome is characterized by defective hepatic apolipoprotein B-100 (apoB) metabolism. Hepato-intestinal cholesterol metabolism may contribute to this abnormality.. We examined the association of cholesterol absorption and synthesis with the kinetics of apoB in 35 obese subjects with the metabolic syndrome. Plasma ratios of campesterol and lathosterol to cholesterol were used to estimate cholesterol absorption and synthesis, respectively. Very-low-density lipoprotein (VLDL), intermediate-density lipoprotein (IDL), and low-density lipoprotein apoB kinetics were studied using stable isotopy and mass spectrometry. Kinetic parameters were derived using multicompartmental modeling.. Compared with controls, the obese subjects had significantly lower plasma ratios of campesterol, but higher plasma ratios of lathosterol (p < 0.05 in both). This was associated with elevated VLDL-apoB secretion rate (p < 0.05) and delayed fractional catabolism of IDL and low-density lipoprotein-apoB (p < 0.01). In the obese group, plasma ratios of campesterol correlated inversely with VLDL-apoB secretion (r = -0.359, p < 0.05), VLDL-apoB (r = -0.513, p < 0.01) and IDL-apoB (r = -0.511, p < 0.01) pool size, and plasma lathosterol ratio (r = -0.366, p < 0.05). Subjects with low cholesterol absorption had significantly higher VLDL-apoB secretion, VLDL-apoB and IDL-apoB pool size, and plasma lathosterol ratio (p < 0.05 in both) than those with high cholesterol absorption.. Subjects with the metabolic syndrome have oversecretion of VLDL-apoB and decreased catabolism of apoB-containing particles and low absorption and high synthesis rates of cholesterol. These changes in cholesterol homeostasis may contribute to the kinetic defects in apoB metabolism in the metabolic syndrome.

Topics: Adult; Apolipoprotein B-100; Apolipoproteins B; Biomarkers; Cholesterol; Homeostasis; Humans; Kinetics; Lipoproteins; Lipoproteins, IDL; Lipoproteins, LDL; Lipoproteins, VLDL; Male; Metabolic Syndrome; Middle Aged; Phytosterols

The aim of this study was to compare the contents of the main biochemical compounds and the antioxidant capacity of five Spanish olive oils by four different antioxidant tests and to find out the most valuable oil for disease preventing diets. Fatty acids, sterols and individual antioxidant compounds in Arbequina, Hojiblanca, Extra Virgin, Picual and Lampante Spanish olive oils were determined. Antioxidant activities were done as well using different radical scavenging activities: total radical-trapping antioxidative potential by ABAP (TRAP-ABAP), radical scavenging activity by DPPH (RSA-DPPH), antioxidant assay by beta-carotene-linoleate model system (AA-beta-carotene) and total antioxidant status by ABTS (TAA-ABTS). The highest content of all studied antioxidant compounds (353; 329; 4.6 and 2.7 mg/kg for tocopherols, tocotrienols, polyphenols and o-diphenols, respectively) was found in Extra Virgin oil. Also the highest antioxidant capacity was observed in Extra Virgin oil (668 nM/ml; 29.4%; 40.4% and 2.64 mM TE/kg for TRAP-ABAP, RSA-DPPH, AA- beta-carotene and TAA-ABTS, respectively). The correlation between total phenols and antioxidant capacities measured by four methods was very high, but the highest for the beta-carotene (R = 0.9958). In conclusion, the best method for determination of the antioxidant capacity of olive oils is the beta-carotene test. Extra Virgin olive oil has high organoleptic properties and the highest antioxidant activity. The above-mentioned makes this oil a preferable choice for diseases preventing diets.

Topics: alpha-Linolenic Acid; Antioxidants; Cholesterol; Fatty Acids, Monounsaturated; Flavonoids; Free Radical Scavengers; Linoleic Acid; Myristic Acid; Oleic Acid; Olive Oil; Palmitic Acid; Phenols; Phytosterols; Plant Oils; Polymers; Polyphenols; Sitosterols; Spain; Stearic Acids

Dietary intake of plant sterol esters (PSE) lowers plasma LDL-cholesterol (LDL-C), but can modestly increase plasma plant sterol concentrations. The objective of the present study was to investigate the impact of increasing doses of dietary PSE on plasma and liver sterol concentrations as well as on aortic foam cell development as a marker of atherogenesis. One-hundred and twenty F(1)B hybrid Syrian golden hamsters (20 per group) were fed a basal atherogenic diet containing 30% of energy as fat and 0.12% (w/w) cholesterol and supplemented with 0, 0.24, 0.48, 0.96, 1.92 and 2.84% (w/w) PSE. After 12 weeks, plasma total cholesterol (TC) and LDL-C were significantly lower in the groups fed PSE compared with control. Plasma plant sterol concentrations increased with increasing dietary PSE intake up to the dietary level of 1.92% and then reached a plateau. On the other hand, hepatic campesterol and sitosterol concentrations plateaued at 0.24% PSE. Foam cell presence in the aortic arch showed an inverse relationship with dietary PSE intake (P<0.0001). Lipid-filled foam cell areas of hamsters receiving 0.24, 0.48 or 2.84% PSE were approximately 70, 90 and 100% smaller than in control hamsters fed no PSE. In summary, dietary PSE lowered plasma TC and LDL-C. Despite an increase in plasma plant sterol concentrations they did not contribute to aortic foam cell development. In fact dietary PSE significantly inhibited aortic foam cell formation. This study supports the concept that PSE through their cholesterol-lowering action prevent development of atherogenesis in this animal model.

Topics: Animals; Aorta; Cholesterol; Cholesterol, Dietary; Cholesterol, LDL; Cricetinae; Diet, Atherogenic; Endothelium, Vascular; Foam Cells; Liver; Male; Mesocricetus; Phytosterols; Sitosterols

Sterols have been shown to reduce plasma cholesterol by blocking the absorption of cholesterol from the gut. The physical properties of crystalline plant sterols limit their use in foods. A coarse-grained structure can be avoided by recrystallisation, a method that affords a reduction in the particle size. A previous work described how to produce a microcrystalline beta-sitosterol suspension. The present study deals with the stability of that suspension. Recrystallisation was carried out by two different methods; one based on rapid the other based on slow cooling, whereby six different compositions were made containing 5-30% of beta-sitosterol and secondly either 5 or 20% water was added. The particle size and habit were evaluated during a 16 weeks storage period (+4 or -19 degrees C) by way of optical microscopy. The crystal structure and degree of crystallinity was analysed by X-ray diffraction. Suspensions can, in most cases, be stored for 16 weeks without any changes to the size and habit. The only evidence of crystal growth came from a suspension with a low sterol concentration at a temperature of +4 degrees C. This is due to the dissolution-diffusion process which is affected by temperature and viscosity. Suspensions containing higher amounts of sterol remained stable, if stored at +4 or -19 degrees C, for 16 weeks. The suspensions included both hemihydrous and monohydrous beta-sitosterol crystals. Suspensions containing less sterol showed greater amounts of monohydrated crystals. This illustrates more water penetration into the crystals. A higher sterol concentration led to a larger number of smaller crystals creating reflections similar to hemihydrated crystals.

Topics: Cholesterol; Drug Stability; Hypolipidemic Agents; Phytosterols; Sitosterols; Soil; Suspensions; Time Factors; Viscosity; Water; X-Ray Diffraction

Plant sterol and stanol esters were separated on a Luna hexyl-phenyl column using a gradient of acetonitrile (90-100%) in water. The eluted compounds were detected by atmospheric pressure chemical ionization (APCI)-mass spectroscopy (MS) in the positive mode. Sterol and stanol esters produced [M + H - HOOCR](+) ions. Application of the hyphenated technique-LC-MS-allowed differentiation between a number of esters of sitosterol, campesterol, stigmasterol, and (tentatively) avenasterol, as well as sitostanol and campestanol esters. With cholesteryl decanoate used as the internal standard, the method showed good linearity, precision, and reproducibility. The method required minimal sample pretreatment and can be applied to samples with high water content (juices) as well as samples with high oil content (margarine spreads). The method could be useful for the analysis of sterol and stanol esters in fortified food products.

Topics: Anticholesteremic Agents; Beverages; Cholesterol; Chromatography, High Pressure Liquid; Citrus; Esters; Fruit; Margarine; Mass Spectrometry; Phytosterols; Sensitivity and Specificity; Sitosterols; Stigmasterol

ABCG5 (G5) and ABCG8 (G8) are ATP-binding cassette (ABC) transporters that limit intestinal absorption and promote biliary excretion of neutral sterols. Mutations in either ABCG5 or ABCG8 result in an identical clinical phenotype, suggesting that these two half-transporters function as heterodimers. Expression of both G5 and G8 is required for either protein to be transported to the plasma membrane of cultured cells. In this paper we used immunofluorescence microscopy to confirm, in vivo, that G5 is localized to the apical membranes of mouse enterocytes and hepatocytes. Other ABC half-transporters function as homodimers or as heterodimers with other subfamily members. To determine whether G5 or G8 complex with other ABCG half-transporters, we co-expressed G1, G2, and G4 with either G5 or G8 in cultured cells. G1, G2, and G4 co-immunoprecipitated with G5, and G4 co-immunoprecipitated with G8, but the putative dimers were retained in the endoplasmic reticulum (ER). Adenovirus-mediated expression of either G5 or G8 in the liver of G5G8 null mice resulted in ER retention of the expressed proteins and no increase in biliary cholesterol. In contrast, co-expression of G5 and G8 resulted in transit of the proteins out of the ER and a 10-fold increase in biliary cholesterol concentration. Finally, adenoviral expression of G2 in the presence or absence of G5 or G8 failed to promote sterol excretion into bile. These experiments indicate that G5 and G8 function as obligate heterodimers to promote sterol excretion into bile.

Topics: Adenosine Triphosphate; Adenoviridae; Amino Acid Sequence; Animals; Antibodies, Monoclonal; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; ATP-Binding Cassette Transporters; Bile Ducts; Biological Transport; Cell Membrane; CHO Cells; Cholesterol; Cloning, Molecular; Cricetinae; Dimerization; DNA, Complementary; Endoplasmic Reticulum; Enterocytes; Epitopes; Evolution, Molecular; Hepatocytes; Humans; Hypolipidemic Agents; Lipoproteins; Liver; Mice; Microscopy, Fluorescence; Molecular Sequence Data; Mutation; Phenotype; Phylogeny; Phytosterols; Precipitin Tests; Protein Transport; Recombinant Proteins; Sequence Homology, Amino Acid; Sitosterols; Transfection

Phytosterol contained in vegetable oils is known to exert a hypocholesterolemic function. In the present study, the antioxidant effects of phytosterol and its components, beta-sitosterol, stigmasterol, and campesterol, against lipid peroxidation were examined by making a comparison with 2,2,5,7,8-pentamethyl-6-chromanol (PMC). It was found that these compounds exerted antioxidant effects on the oxidation of methyl linoleate in solution and its effect decreased in the order of: PMC >> phytosterol approximately campesterol approximately beta-sitosterol > stigmasterol. Phytosterol also suppressed the oxidation and consumption of alpha-tocopherol in beta-linoleoyl-gamma-palmitoyl phosphatidylcholine (PLPC) liposomal membranes, the effects being more significant than dimyristoyl PC of the same concentration. Stigmasterol accelerated the oxidation of both methyl linoleate in solution and PLPC liposomal membranes in aqueous dispersions, which was ascribed to the oxidation of allylic hydrogens at the 21- and 24-positions. Taken together, the present study shows that phytosterol chemically acts as an antioxidant, a modest radical scavenger, and physically as a stabilizer in the membranes.

Topics: Anticholesteremic Agents; Antioxidants; Cholesterol; Chromans; Free Radical Scavengers; Lipid Peroxidation; Liposomes; Membranes, Artificial; Oxidation-Reduction; Phytosterols; Sitosterols; Stigmasterol

Campesterol is present in all the phytosterol-containing dietary hypocholesterolemic agents in current use. Campesterol is absorbed more efficiently than sitosterol, and the question of its possible atherogenicity has been raised. To test this possibility, rabbits were fed either a semipurified, cholesterol-free diet that has been shown to be atherogenic for this species or the same diet augmented with 0.5 g of phytosterol-rich diet preparations (spreads) containing either sitosterol or sitostanol. The diets contained 295 mg phytosterol per 100 g. After 60 d, serum cholesterol levels in the two phytosterol groups were 78 +/- 4 mg/dL (sitosterol) and 76 +/- 4 mg/dL (sitostanol), respectively. The serum cholesterol level of rabbits fed the control diet was 105 +/- 8 mg/dL. Serum campesterol (microg/mL) levels were higher than sitosterol or sitostanol levels in all groups. Aortic phytosterols were present in nanogram quantities compared to cholesterol, which was present in microgram quantities. The ratio of campesterol/sitosterol/sitostanol in the aortas was: control, 1.00:0.43:0.02; sitosterol, 1:00:0.32:0.01; sitostanol, 1:00:0.34:0.11. Aortic campesterol was present at 4% the concentration of aortic cholesterol, sitosterol at 1.4%, and sitostanol at 0.14%. Aortic lesions were not present in any of the animals.

Topics: Animals; Aorta; Cholesterol; Chromatography, Gas; Diet; Esters; Male; Phytosterols; Rabbits; Sitosterols; Weight Gain

The analysis of 4 commonly available amaranth varieties (Amaranthus K343, RRC1011, K433, K432) revealed the presence of all three major phytosterols (beta-sitosterol, campesterol, stigmas-terol) with a total sterol content being several fold higher than those found in other studied plants. Substantial differences in total phytosterol content and beta-sitosterol content were found between the amaranth varieties. The most commonly cultivated amaranth variety in the United States, i.e., Amaranthus K343 was found to possess the highest levels of phytosterols of the varieties tested. The possibility of screening for superior amaranth varieties with various health properties is outlined.

Topics: Amaranthus; Cholesterol; Food, Organic; Nutritive Value; Phytosterols; Sitosterols; Stigmasterol

The factors responsible for ALS-parkinsonism dementia complex (ALS-PDC), the unique neurological disorder of Guam, remain unresolved, but identification of causal factors could lead to clues for related neurodegenerative disorders elsewhere. Earlier studies focused on the consumption and toxicity of the seed of Cycas circinalis, a traditional staple of the indigenous diet, but found no convincing evidence for toxin-linked neurodegeneration. We have reassessed the issue in a series of in vitro bioassays designed to isolate non-water soluble compounds from washed cycad flour and have identified three sterol beta-d-glucosides as potential neurotoxins. These compounds give depolarizing field potentials in cortical slices, induce alterations in the activity of specific protein kinases, and cause release of glutamate. They are also highly toxic, leading to release of lactate dehydrogenase (LDH). Theaglycone form, however, is non-toxic. NMDA receptor antagonists block the actions of the sterol glucosides, but do not compete for binding to the NMDA receptor. The most probable mechanism leading to cell death may involve glutamate neuro/excitotoxicity. Mice fed cycad seed flour containing the isolated sterol glucosides show behavioral and neuropathological outcomes, including increased TdT-mediated biotin-dUTP nick-end labelling (TUNEL) positivity in various CNS regions. Astrocytes in culture showed increased caspase-3 labeling after exposure to sterol glucosides. The present results support the hypothesis that cycad consumption may be an important factor in the etiology of ALS-PDC and further suggest that some sterol glucosides may be involved in other neurodegenerative disorders.

Topics: Amyotrophic Lateral Sclerosis; Animals; Astrocytes; Biological Assay; Cells, Cultured; Cerebral Cortex; Cholesterol; Cycas; Dementia; Glucose; Glucosides; Guam; Humans; In Vitro Techniques; Male; Mice; Neurons; Neurotoxins; Parkinsonian Disorders; Patch-Clamp Techniques; Phytosterols; Plant Extracts; Rats; Rats, Sprague-Dawley; Receptors, N-Methyl-D-Aspartate; Seeds; Sitosterols; Stigmasterol

The short-term cholesterol-lowering efficacy of plant stanol esters has been open to debate, and the data from different clinical studies with hypercholesterolemic subjects are variable, partly due to lack of systematic studies. Therefore, we investigated the time in days needed to obtain the full cholesterol-lowering effect of stanol esters in hypercholesterolemic subjects.. Eleven mildly to moderately hypercholesterolemic subjects consumed stanol ester margarine (2.0 g/day of stanols) as a part of their habitual diet for 14 days and the changes in serum lipid values were measured three times at 4, 8 and 15 days after the initiation of test margarine consumption (0 day). The returning of serum lipid concentrations to baseline was measured two times after 2 or 3 days and after 7 days of the end of the test margarine consumption.. Serum LDL cholesterol concentrations were reduced from 0 day (4.51 +/- 0.66 mmol/l) by 3.5% (P = ns), 9.9% (p < 0.05) and 10.2% (P < 0.05) at 4, 8 and 15 days, respectively. Serum campesterol/total cholesterol ratio, an indirect marker of intestinal cholesterol absorption, was significantly reduced on day 4 already. After ending the stanol ester use serum cholesterol concentrations began to return rapidly and after 7 days serum LDL cholesterol was 5.3% less than the initial value (P = ns).. The specific effect of plant stanol esters on serum LDL cholesterol can fully be obtained within 1-2 weeks of the use of plant stanol ester-enriched margarine.

Topics: Adult; Aged; Analysis of Variance; Anticholesteremic Agents; Biomarkers; Body Mass Index; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Cholesterol, VLDL; Female; Humans; Hypercholesterolemia; Lipids; Male; Margarine; Middle Aged; Phytosterols; Phytotherapy; Sitosterols; Time Factors

The first committed step in the conversion of cycloartenol into Delta(5) C24-alkyl sterols in plants is catalyzed by an S-adenosyl-methionine-dependent sterol-C24-methyltransferase type 1 (SMT1). We report the consequences of overexpressing SMT1 in tobacco (Nicotiana tabacum), under control of either the constitutive carnation etched ring virus promoter or the seed-specific Brassica napus acyl-carrier protein promoter, on sterol biosynthesis in seed tissue. Overexpression of SMT1 with either promoter increased the amount of total sterols in seed tissue by up to 44%. The sterol composition was also perturbed with levels of sitosterol increased by up to 50% and levels of isofucosterol and campesterol increased by up to 80%, whereas levels of cycloartenol and cholesterol were decreased by up to 53% and 34%, respectively. Concomitant with the enhanced SMT1 activity was an increase in endogenous 3-hydroxy-3-methylglutaryl coenzyme A reductase activity, from which one can speculate that reduced levels of cycloartenol feed back to up-regulate 3-hydroxy-3-methylglutaryl coenzyme A reductase activity and thereby control the carbon flux into sterol biosynthesis. This potential regulatory role of SMT1 in seed sterol biosynthesis is discussed.

Topics: Biological Transport; Carbon; Cholesterol; Cloning, Molecular; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Plant; Hydroxymethylglutaryl CoA Reductases; Methyltransferases; Nicotiana; Phytosterols; Plant Leaves; Plants, Genetically Modified; Seeds; Sitosterols; Stigmasterol; Triterpenes

Low birth weight may be associated with high levels of cholesterol in later life through genetic factors that affect both birth weight and cholesterol metabolism. Alterations in cholesterol synthesis and absorption may play an important role in this association. We examined birth weight and plasma ratios of a precursor of cholesterol, lathosterol (an estimate of cholesterol synthesis), and plant sterols, campesterol and beta-sitosterol (estimates of cholesterol absorption), to cholesterol in 53 dizygotic and 58 monozygotic adolescent twin pairs. After adjustment for current weight, birth weight was not associated with the ratios of lathosterol, campesterol, and beta-sitosterol either in the overall sample [+0.07 micro mol/mmol/kg (95% confidence interval: -0.11 to 0.25), p = 0.5; +0.02 micro mol/mmol/kg (-0.33 to 0.37), p = 0.9; and -0.04 micro mol/mmol/kg (-0.23 to 0.15), p = 0.8, respectively] or in the intrapair analysis in dizygotic twins [+0.27 micro mol/mmol/kg (-0.28 to 0.82), p = 0.3; -0.03 micro mol/mmol/kg (-1.07 to 1.01), p = 1.0; and +0.04 micro mol/mmol/kg (-0.56 to 0.64), p = 0.9, respectively] or in the intrapair analysis in monozygotic twins [+0.54 micro mol/mmol/kg (-0.09 to 1.18), p = 0.09; -0.60 micro mol/mmol/kg (-1.59 to 0.39), p = 0.2; and -0.43 micro mol/mmol/kg (-0.99 to 0.14), p = 0.14, respectively]. Plasma levels of lathosterol, campesterol, and beta-sitosterol, which are indicators of cholesterol synthesis and absorption, thus do not explain the association of low birth weight with high levels of total and LDL cholesterol. As an alternative hypothesis, we suggest that a decrease in cholesterol clearance may play an important role.

Topics: Absorption; Adolescent; Biomarkers; Birth Weight; Cholesterol; Diseases in Twins; Female; Humans; Hypercholesterolemia; Infant, Low Birth Weight; Infant, Newborn; Male; Phytosterols; Risk Factors; Sitosterols; Twins, Dizygotic; Twins, Monozygotic

Cholesterol and other sterols exit the body primarily by secretion into bile. In patients with sitosterolemia, mutations in either of two ATP-binding cassette (ABC) half-transporters, ABCG5 or ABCG8, lead to reduced secretion of sterols into bile, implicating these transporters in this process. To elucidate the roles of ABCG5 and ABCG8 in the trafficking of sterols, we disrupted Abcg5 and Abcg8 in mice (G5G8(-/-)). The G5G8(-/-) mice had a 2- to 3-fold increase in the fractional absorption of dietary plant sterols, which was associated with an approximately 30-fold increase in plasma sitosterol. Biliary cholesterol concentrations were extremely low in the G5G8(-/-) mice when compared with wild-type animals (mean = 0.4 vs. 5.5 micromol ml) and increased only modestly with cholesterol feeding. Plasma and liver cholesterol levels were reduced by 50% in the chow-fed G5G8(-/-) mice and increased 2.4- and 18-fold, respectively, after cholesterol feeding. These data indicate that ABCG5 and ABCG8 are required for efficient secretion of cholesterol into bile and that disruption of these genes increases dramatically the responsiveness of plasma and hepatic cholesterol levels to changes in dietary cholesterol content.

Topics: Animal Feed; Animals; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; ATP-Binding Cassette Transporters; Bile; Biological Transport; Chimera; Cholestanol; Cholesterol; Cholesterol, Dietary; Crosses, Genetic; Dietary Fats; Female; Gene Targeting; Intestinal Absorption; Intestinal Mucosa; Lipoproteins; Liver; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Phytosterols; Sitosterols

Plasma plant sterol levels differ among humans due to genetic and dietary factors. A disease characterized by high plasma plant sterol levels, beta-sitosterolemia, was recently found to be due to mutations at the ABCG5ABCG8 locus. To detect variants at this and other loci, a genetic cross was carried out between two laboratory mouse strains. Parental C57BL6J had almost twice the campesterol and sitosterol levels compared with parental CASARk mice, and F(1) mice had levels halfway between the parentals. An intercross between F(1)s was performed and plasma plant sterol levels measured in 102 male and 99 female F(2) mice. Plasma plant sterols in F(2)s displayed a unimodal distribution, suggesting the effects of several rather a single major gene. In the F(2) mice, a full genome scan revealed significant linkages on chromosomes 14 and 2. With regard to chromosome 14, analysis showed a single peak for linkage at 17 cM with a logarithm of odds (LOD) score of 9.9, designated plasma plant sterol 14 (Plast14). With regard to chromosome 2, analysis showed two significant peaks for linkage at 18 and 65 cMs with LOD scores of 4.1 and 3.65, respectively, designated Plast2a and Plast2b, respectively. Four interactions between loci, predominantly of an additive nature, were also demonstrated, the most significant between Plast14 and Plast2b (LOD 16.44). No significant linkage or gene interaction was detected for the ABCG5ABCG8 locus on chromosome 17. Therefore, other genes besides ABCG5ABCG8 influence plasma plant sterol levels and now become candidates to explain differences in plasma plant sterol levels between humans.

Topics: Animals; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP Binding Cassette Transporter, Subfamily G, Member 8; ATP-Binding Cassette Transporters; Biomarkers; Cholesterol; Chromosome Mapping; Crosses, Genetic; Dietary Fats; Epistasis, Genetic; Female; Genotype; Lipoproteins; Male; Mice; Mice, Inbred C57BL; Mice, Inbred Strains; Phytosterols; Sitosterols; Species Specificity

In patients with the inherited disease of phytosterolemia, elevated concentrations of plant sterols (eg, campesterol and sitosterol) have been implicated as a risk factor for premature atherosclerosis. Whether plasma concentrations of campesterol and sitosterol are risk factors for coronary heart disease (CHD) in nonphytosterolemia subjects has not been established. Therefore, the present study examined the role of plant sterols in patients admitted for elective artery coronary bypass graft (ACBG). Serum concentrations of campesterol and sitosterol, as well as lathosterol, desmosterol, cholestanol, and lipoproteins were analyzed in 42 men and 11 women without lipid-lowering treatment during the past. Twenty-six patients reported a positive family history in their first-degree relatives for CHD. Lipid profile and other risk factors were comparable in both groups. Patients with a positive family history for CHD had significant higher plasma levels of campesterol (.50 +/-.17 v.38 +/-.16 mg/dL; P =.011), sitosterol (.40 +/-.11 v.31 +/-.11 mg/dL; P =.004) and their ratios to cholesterol. Lathosterol, desmosterol, cholestanol, and their ratios to cholesterol were not significantly different. Analysis of covariance (ANCOVA) analysis showed no influence of sex, age, triglycerides, total-, low-density lipoprotein (LDL)-, and high-density lipoprotein (HDL)-cholesterol on the results, but confirmed a strong influence of plant sterols. These findings support the hypothesis that plant sterols might be an additional risk factor for CHD.

Topics: Aged; Cholesterol; Coronary Disease; Family; Female; Humans; Male; Medical Records; Middle Aged; Osmolar Concentration; Phytosterols; Risk Factors; Sitosterols

North American ginseng (Panax quinquefolium L.) oil was saponifed and the unsaponifiable matter trimethylsilylated. The phytosterol fraction of hexane-extracted, air-dried seed was quantified and identified by GC and GC-MS. Phytosterol contents (milligrams per 100 g of oil) were as follows: squalene (514-569), oxidosqualene (8.97-48.2), campesterol (9.96-12.4), stigmasterol (93.2-113), clerosterol (1.91-2.14), beta-sitosterol (153-186), beta-amyrin (11.7-19.5), delta(5)-avenasterol (12.4-20.5), delta(5,24(25))-stigmasterol (3.70-.76), lupeol (14.4-15.2), delta(7)-sitosterol (12.5-14.6), delta(7)-avenasterol (4.11-8.09), 24-methylenecycloartanol (1.94-4.76), and citrostadienol (2.50-3.81). Seed stratification lowered the phytosterol levels. Oven-drying gave mixed results, and phytosterols varied slightly between the 1999 and 2000 harvests.

Topics: Cholesterol; Chromatography, Gas; Gas Chromatography-Mass Spectrometry; Oleanolic Acid; Panax; Phytosterols; Plant Oils; Seeds; Sitosterols; Squalene; Stigmasterol; Triterpenes

The Protected Designation of Origin (PDO) "Riviera Ligure" for extra-virgin olive oils from Liguria specifies three additional geographical mentions corresponding to three different geographical areas. To obtain a complete characterization of this typical Italian product, 217 samples of olive oils produced in this North Italian region during 1998/99 and 1999/2000 were analyzed. For each sample 31 variables were determined by chemical-physical analyses, and the data were subjected to a multivariate statistical analysis. For the 1998/99 crop, characterized by favorable climatic conditions, class-models of the three geographical areas were obtained with good predictive ability, also considering the influence of the month of olive harvesting. The oil samples from the 1999/2000 crop were similarly studied, but bad climatic conditions and a widespread Dacus oleae infestation leveled out the peculiar features of the oils produced in the three areas.

Topics: Agriculture; Analysis of Variance; Cholesterol; Climate; Hydrogen-Ion Concentration; Italy; Linoleic Acid; Oleic Acid; Olive Oil; Palmitic Acid; Phytosterols; Plant Oils; Stigmasterol

Differences in genetic constitution may affect cholesterol metabolism and responses to diet. Identification of common variations in genes related to dietary responsiveness is therefore an attractive goal to be able to prescribe individually tailored diets for the treatment of dyslipidaemia.. We have examined relationships between serum lipids and lipoproteins, cholesterol-standardized campesterol and lathosterol concentrations with genetic variation, and the presence of a gene-diet interaction between plant stanol ester consumption. Candidate genes were apolipoprotein A-IV (apoA-IV), scavenger receptor-BI (SR-BI), cholesterol ester transfer protein (CETP), 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, and apolipoprotein E (apoE). These relations were examined in 112 nonhypercholesterolaemic subjects, of whom 70 consumed 3.8-4.0 g plant stanol esters a day for 8 weeks.. At baseline, high-density lipoprotein (HDL) concentrations of 1.56 +/- 0.36 mmol L(-1) in SR-BI-2 allele carriers tended to be lower compared to the 1.72 +/- 0.42 mmol L(-1) in SR-BI-1/1 subjects (P = 0.069). Cholesterol standardized lathosterol concentrations were also lower in the SR-BI-2 allele carriers (P = 0.002). Furthermore, low-density lipoprotein (LDL) cholesterol concentrations in apoE2 subjects, were lower compared to the LDL cholesterol concentration in apoE3 group (P = 0.002) and apoE4 subjects (P < 0.001). No significant differences between the polymorphisms and dietary responsiveness to plant stanol ester consumption could be found, which indicates that it is unlikely that one of the single polymorphisms analysed in this study is a major factor in explaining the variation in serum LDL cholesterol responses.. These findings suggest that all subjects who want to lower their cholesterol concentration, will benefit from plant stanol ester consumption, irrespective of their apoA-IV, SR-BI, HMG-CoA reductase, CETP, or apoE genotype.

Topics: Adult; Apolipoproteins A; Apolipoproteins E; Carrier Proteins; CD36 Antigens; Cholesterol; Cholesterol Ester Transfer Proteins; Cholesterol, LDL; Diet; Female; Genetic Variation; Glycoproteins; Humans; Hydroxymethylglutaryl CoA Reductases; Lipids; Lipoproteins; Lipoproteins, HDL; Lipoproteins, LDL; Male; Membrane Proteins; Phytosterols; Polymorphism, Genetic; Receptors, Immunologic; Receptors, Lipoprotein; Receptors, Scavenger; Scavenger Receptors, Class B; Sitosterols

This paper elaborates an improved synthesis of crinosterol and campesterol starting from stigmasterol. The proposed approach is based on Claisen rearrangement of Delta23-22-allylic alcohols with various configurations of the 22-hydroxy group and geometry of the Delta23-double bond. It allows complete use of the starting steroid for preparing 24alpha-methyl derivatives. It was possible to partially control the stereochemistry at C-25. Hydrogenation of the Delta22-double bond was shown to proceed with partial isomerization of the C-24 alkyl substituent. The Ireland ester enolate variant of the Claisen rearrangement was demonstrated to be useful for preparing 24alpha-methyl steroids containing the Delta22,25-system.

Topics: Alcohols; Cholesterol; Molecular Structure; Phytosterols; Steroids; Sterols

Stanyl esters dissolved in margarine inhibit cholesterol absorption, lower sterol absorption in general, and lower serum total cholesterol, LDL-cholesterol and plant sterol levels. To find out whether stanyl esters inhibit absorption of fat-soluble vitamins and beta-carotene in acute experiments, we performed two fat-tolerance tests fortified with vitamins (retinol 0.9-3.7 mg, alpha-tocopherol 70-581 mg), beta-carotene (25-150 mg) and squalene (0.5 g) with and without 1 g of stanyl ester added to the test meal in ten healthy men. The concentrations or areas under the curves (AUC) of cholesterol, triacylglycerols, squalene and alpha-tocopherol, beta-carotene and retinyl palmitate showed typical postprandial changes in serum, chylomicrons, VLDL and VLDL infranatant (intermediate-density lipoproteins, LDL and HDL) over 24 h after the test meal without stanyl esters, and they were not affected by the addition of stanyl esters. The post-absorptive serum campesterol concentration and campesterol : cholesterol were significantly lowered at 6-9 h by stanyl ester supplementation, reflecting reduced sterol absorption efficiency. Changes in vitamin and beta-carotene AUC did not correlate with the given doses. In conclusion, the present study shows that stanyl esters dissolved in margarine do not detectably interfere in a short-term study with the absorption of alpha-tocopherol, beta-carotene or retinol measured by a 24 h oral fat-load test.

Topics: Analysis of Variance; Area Under Curve; beta Carotene; Cholesterol; Chylomicrons; Dose-Response Relationship, Drug; Esters; Humans; Intestinal Absorption; Male; Middle Aged; Palmitates; Phytosterols; Postprandial Period; Sitosterols; Squalene; Statistics, Nonparametric; Triglycerides; Vitamin A; Vitamin E

The Arabidopsis genome contains three distinct genes encoding sterol-C24-methyltransferases (SMTs) involved in sterol biosynthesis. The expression of one of them, STEROL METHYLTRANSFERASE 2;1, was modulated in 35S:SMT2;1 Arabidopsis in order to study its physiological function. Plants overexpressing the transgene accumulate sitosterol, a 24-ethylsterol which is thought to be the typical plant membrane reinforcer, at the expense of campesterol. These plants displayed a reduced stature and growth that could be restored by brassinosteroid treatment. Plants showing co-suppression of SMT2;1 were characterized by a predominant 24-methylsterol biosynthetic pathway leading to a high campesterol content and a depletion in sitosterol. Pleiotropic effects on development such as reduced growth, increased branching, and low fertility of high-campesterol plants were not modified by exogenous brassinosteroids, indicating specific sterol requirements to promote normal development. Thus SMT2;1 has a crucial role in balancing the ratio of campesterol to sitosterol in order to fit both growth requirements and membrane integrity.

Topics: Amino Acid Sequence; Arabidopsis; Blotting, Northern; Brassinosteroids; Cholestanols; Cholesterol; Fruit; Gene Expression Regulation, Plant; Methyltransferases; Molecular Sequence Data; Phenotype; Phytosterols; Plant Growth Regulators; Plant Roots; Plant Stems; Plants, Genetically Modified; Sitosterols; Steroids, Heterocyclic; Sterols; Transgenes

We have studied metabolism of plant sterols and squalene administered intravenously in the form of lipid emulsion mimicking chylomicrons (CM). The CM-like lipid emulsion was prepared by dissolving squalene in commercially available Intralipid. The emulsion was given as an intravenous bolus injection of 30 ml containing 6.3 mg of cholesterol, 1.9 mg of campesterol, 5.7 mg of sitosterol, 1.6 mg of stigmasterol, 18.1 mg of squalene, and 6 g of triglycerides in six healthy volunteers. Blood samples were drawn from the opposite arm before and serially 2.5 -180 min after the injections. The decay of CM squalene, plant sterols, and triglycerides was monoexponential. The half-life of CM squalene was 74 +/- 8 min, that of campesterol was 37 +/- 5 min (P < 0.01 from squalene), and those of sitosterol, stigmasterol, and triglycerides were 17 +/- 2, 15 +/- 1, and 17 +/- 2 min, respectively (P < 0.01 from squalene and campesterol). The CM squalene concentration still exceeded the baseline level 180 min after injection (P = 0.02), whereas plant sterols and triglycerides returned to the baseline level between 45 and 120 min after injection. The half-lives of squalene and campesterol were positively correlated with their fasting CM concentrations. In addition, VLDL squalene, campesterol, and triglyceride concentrations, VLDL, LDL, and HDL sitosterol concentrations, as well as VLDL and LDL stigmasterol concentrations were increased significantly. Cholesterol concentrations increased in VLDL (P < 0.05), but were unchanged in CM after injection. These data suggest that squalene clearance occurs more slowly than that of plant sterols and triglycerides from CM, and that squalene is more tightly associated with triglyceride-rich lipoproteins than are plant sterols in injected CM-like emulsions.

Topics: Adult; Cholesterol; Humans; Hypolipidemic Agents; Lipoproteins, HDL; Lipoproteins, LDL; Lipoproteins, VLDL; Male; Middle Aged; Phytosterols; Postprandial Period; Sitosterols; Squalene; Stigmasterol; Time Factors; Triglycerides

Phytosterols are plant sterols that are structurally similar to cholesterol and are characterized by anti-carcinogenic and anti-atherogenic properties. Beta-sitosterol and campesterol are the predominant phytosterols in blood. The present study aimed to analyse the reproducibility and overtime reliability of plasma beta-sitosterol and campesterol measurements. In order to study the reproducibility of the measurement (technical variability), three healthy premenopausal women donated a sample of their blood. Each blood sample was subdivided into six aliquots and analysed within the same run by the same laboratory technician. The intraclass correlation coefficients (ICCs) of the assay for plasma beta-sitosterol and campesterol were 0.88 and 0.94 (95% confidence intervals low bounds (95% CI(low)) were 0.66 and 0.82), respectively. To study the reliability of beta-sitosterol and campesterol measurement over time, seven premenopausal women were recruited. Over a 6-month period, each woman provided a fasting blood sample once a month at the same time of day, and the same numerical day of the luteal phase of her menstrual cycle (between the 20th and 24th day of her menstrual cycle). All plasma samples from the same individual were processed together at the same time by the same technician at the end of the 6-month period. The overtime ICCs of plasma beta-sitosterol and campesterol were 0.91 (95% CI(low) 0.49) and 0.58 (95% CI(low) 0.31), respectively. The high reproducibility and good overtime reliability of plasma beta-sitosterol and campesterol measurements indicate that they may be suitable for potential clinical and population-based studies on cancer prevention.

Topics: Adult; Anticarcinogenic Agents; Biomarkers, Tumor; Cholesterol; Female; Humans; Luteal Phase; Middle Aged; Neoplasms; Phytosterols; Reproducibility of Results; Sitosterols

Plant sterols in vegetable foods might prevent colorectal cancer.. The objective was to study plant sterol intakes in relation to colorectal cancer risk in an epidemiologic study.. The study was performed within the framework of the Netherlands Cohort Study on Diet and Cancer in 120852 subjects who completed a baseline questionnaire in 1986. After 6.3 y of follow-up, 620 colon and 344 rectal cancer cases were detected. A case-cohort approach was used to calculate confounder-adjusted rate ratios (RRs) and their 95% CIs for quintiles of plant sterol intake.. The total mean (+/-SD) intake of campesterol, stigmasterol, beta-sitosterol, campestanol, and beta-sitostanol was 285 +/- 97 mg/d. Major contributors to plant sterol intake were bread (38%), vegetable fats (26%), and fruit and vegetables (21%). For men, there was no clear association between intake of any of the plant sterols and colon cancer risk when age, smoking, alcohol use, family history of colorectal cancer, education level, and cholecystectomy were controlled for. Adjustment for energy did not alter the result. For rectal cancer, adjustment for energy resulted in positive associations between risk and campesterol and stigmasterol intakes. For women, there was no clear association between intake of any of the plant sterols and colorectal cancer risk.. A high dietary intake of plant sterols was not associated with a lower risk of colon and rectal cancers in the Netherlands Cohort Study on Diet and Cancer.

Topics: Aged; Bread; Case-Control Studies; Cholesterol; Cohort Studies; Colorectal Neoplasms; Confounding Factors, Epidemiologic; Dietary Fats; Female; Follow-Up Studies; Fruit; Humans; Hypolipidemic Agents; Male; Middle Aged; Netherlands; Phytosterols; Prospective Studies; Rectal Neoplasms; Risk Factors; Sitosterols; Stigmasterol; Surveys and Questionnaires; Vegetables

Analysis of sterol composition in serum, liver, adipose tissue, adrenals, and abdominal aorta demonstrated that the contents of plant sterols, campesterol and sitosterol, were evidently higher in WKY and stroke-prone spontaneously hypertensive (SHRSP) rats than in Wistar and WKA rats fed a diet containing a 0.5% plant sterol mixture. Lymphatic 24-hour recovery of 3H-sitosterol was about 2-fold higher in the WKY and SHRSP rats than in the WKA rats. Lymphatic absorption of 14C-cholesterol was also higher in WKY and SHRSP rats compared with WKA rats, but the difference was smaller than in the case of sitosterol. The remarkable increase of sitosterol absorption in WKY and SHRSP rats was observed between 9 and 24 hours after the administration. In SHRSP rats, lymphatic absorption of sitosterol between 0 and 3 hours was also higher than those in the other rat strains. Markedly less esterified 3H-sitosterol was detected in lymph than 14C-cholesterol in all strains, and in WKY and SHRSP rats, only a small increase in the esterified forms of sitosterol and cholesterol was observed. Although the incorporation of micellar 3H-sitosterol and 14C-cholesterol into intestinal brush border membranes was higher in SHRSP rats than in WKA rats, no difference was observed between WKY and WKA rats. These observations suggest that the incorporation into the brush border membranes and the esterification of sterols are not the major determinants for the hyperabsorption of sitosterol and cholesterol in SHRSP and WKY rats. Secretion of sitosterol and cholesterol in the bile of rats fed a plant sterol mixture was lower in SHRSP than in WKA rats. These results suggest that WKY and SHRSP strains deposit plant sterols in the body by enhancing the absorption and lowering the excretion of plant sterols. These strains of rats may be suitable models for studying mechanisms of differential absorption of various sterols.

Topics: Adipose Tissue; Adrenal Glands; Animals; Aorta, Abdominal; Bile; Cholesterol; Dietary Supplements; Genetic Predisposition to Disease; Hypolipidemic Agents; Intestinal Mucosa; Liver; Lymphatic System; Male; Microvilli; Organ Specificity; Phytosterols; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Rats, Wistar; Sitosterols; Species Specificity; Stroke

Topics: Aged; Aging; Cholesterol; Clinical Trials as Topic; Female; Finland; Hawaii; Humans; Male; Mortality; Phytosterols

The dietary effect of phytosterols (PS) versus cholesterol on the growth and metastasis of the PC-3 human prostate cancer cells in SCID mice was studied. Also, their direct effect on the growth and migration of these cells in vitro was analysed. In the in vivo experiment, SCID mice were fed a diet containing 2% of either PS mixture or cholesterol plus 0.2% cholic acid and implanted with 2 x 10(6) tumour cells per mouse. Tumour growth was monitored for 8 weeks post inoculation. Animals fed the PS diet had tumours 40-43% smaller than those fed the cholesterol diet. Furthermore, the number of mice with lymph node and lung metastasis was almost one-half that of the cholesterol-fed group. In the in vitro studies, both beta-sitosterol and campesterol inhibited the growth of PC-3 cells by 70% and 14%, respectively, while cholesterol supplementation increased the growth by 18% when compared with controls. PS inhibited the invasion of PC-3 cells into Matrigel-coated membranes by 78% while cholesterol increased it by 43% as compared with the cells in the control media. Migration of tumour cells through 8 microm pore membranes was reduced by 60-93% when the PC-3 cells were in PS media, as compared with a 67% increase after cholesterol supplementation. PS supplementation reduced the binding of PC-3 cells to laminin by 15-38% and fibronectin by 23% while cholesterol increased binding to type IV collagen by 36%. It was concluded that PS indirectly (in vivo as a dietary supplement) and directly (in tissue culture media) inhibited the growth and metastasis of PC-3 cells. beta-Sitosterol was more effective than campesterol in offering this protection in most of the parameters studied.

Topics: Animals; Body Weight; Cell Adhesion; Cholesterol; Humans; Male; Mice; Mice, SCID; Models, Animal; Neoplasm Metastasis; Phytosterols; Prostatic Neoplasms; Sitosterols; Tumor Cells, Cultured

The purpose of the study was to investigate whether cholesterol metabolism is associated with coronary artery disease (CAD) in postmenopausal women.. Although hypercholesterolemia, a predominant risk factor of CAD, is related to cholesterol metabolism, the association between cholesterol metabolism and CAD is not well known.. In addition to conventional coronary risk factors, fasting serum squalene, delta8-cholestenol, desmosterol, lathosterol (indicators of cholesterol synthesis), cholestanol, campesterol and sitosterol (indicators of cholesterol absorption) were measured in 48 50- to 55-year-old consecutive women with angiographically verified CAD and in 61 age-matched healthy controls.. The coronary patients had elevated ratios of squalene (p < 0.001), desmosterol (p = 0.005), campesterol (p = 0.028) and sitosterol (p = 0.022) to cholesterol, but had lower respective lathosterol value (p = 0.041) compared with the controls, despite similar serum cholesterol levels. Adjusted for age, body mass index, family history of CAD, smoking, hypertension, serum triglycerides, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol level and glycosylated hemoglobin A1c% (GHbA1c), the ratios of squalene (odds ratio, 1.36; 95% confidence interval, 1.17 to 1.57), lathosterol (0.98; 0.97 to 0.99), campesterol (1.01; 1.00 to 1.01) and sitosterol (1.01; 1.00 to 1.03) were significantly associated with the risk of CAD. In addition, family history of CAD and GHbA1c% were also independently related to the presence of CAD.. The results suggest that women with elevated ratios of serum squalene, campesterol and sitosterol to cholesterol and low respective lathosterol values have enhanced risk for CAD. Thus, enhanced absorption and reduced synthesis of cholesterol may be related to coronary atherosclerosis.

Topics: Case-Control Studies; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Coronary Disease; Desmosterol; Fasting; Female; Glycated Hemoglobin; Humans; Middle Aged; Phytosterols; Postmenopause; Prevalence; Radiography; Reproducibility of Results; Risk Factors; Sensitivity and Specificity; Sitosterols; Squalene

Epidemiological and experimental studies have suggested a protective role of phytosterols (PS) in the development of some types of cancer such as colon and prostate cancer. No work has been reported on the role of PS in the development of breast cancer, the second leading cancer in woman. The present study was designed to examine the effect of the two most common dietary PS, beta-sitosterol (SIT) and campesterol, as compared to cholesterol, the main sterol in the Western diet, on growth, apoptosis and cytotoxicity of MDA-MB-231 human breast cancer cells in culture. In addition, we investigated the possible role of protein phosphatase 2A (PP2A), an enzyme that has been shown to regulate growth and apoptosis in tumor parameters studied. Breast cancer cell growth was found to be inhibited by 66% after 3 days and 80% after 5 days with 16 microM SIT. Both campesterol and cholesterol sustained tumor growth at levels comparable to that of the vehicle control. None of the sterols tested at this level (16 microM) induced cytotoxicity as measured by lactic dehydrogenase release. SIT supplementation for 3 days at 16 microM resulted in a 6-fold increase in apoptosis in cells when compared to cholesterol treated cells. SIT treatment was found to have no effect on the level and content of tumor cell PP2A. It is concluded that SIT, by a still unknown mechanism, may offer protection from breast cancer by inhibiting growth and stimulating apoptosis.

Topics: Apoptosis; Breast Neoplasms; Cell Division; Cholesterol; Dose-Response Relationship, Drug; Female; Humans; L-Lactate Dehydrogenase; Phosphoprotein Phosphatases; Phytosterols; Protein Phosphatase 2; Sitosterols; Tumor Cells, Cultured

Higher plant cells contain a mixture of 24-desmethyl, 24-methyl(ene), and 24-ethyl(idene) sterols in given proportions according to species but also to cell type. As a first step to investigate the function of such sterol compositions in the physiology of a plant, we have illustrated in the present work the coexistence of two distinct (S)-adenosyl-L-methionine sterol-C24-methyltransferases (SMT) in transgenic Nicotiana tabacum L. Indeed, modulation of the expression of the tobacco gene SMT1-1, which encodes a cycloartenol-C24-methyltransferase, results in variations of the proportion of cycloartenol and a concomitant effect on the proportion of 24-ethyl sterols. Overexpression in tobacco of the Arabidopsis thaliana (L.) Heynh. gene SMT2-1 which encodes a 24-methylene lophenol-C24(1)-methyltransferase, results in a dramatic modification of the ratio of 24-methyl cholesterol to sitosterol associated with a reduced growth, a topic discussed in the present work.

Topics: Arabidopsis; Cholesterol; Methyltransferases; Nicotiana; Phytosterols; Plants, Genetically Modified; Plants, Toxic; Sitosterols; Sterols

Cholesterol metabolic studies are simplified in colectomized patients because of rapid intestinal passage and reduced bacterial action.. Our objective was to study the effect on cholesterol and plant sterol metabolism of feeding a margarine containing stanol ester to 11 colectomized patients.. A margarine containing 2 g stanol was consumed for 7-18 d. Serum, biliary, and fecal lipids were measured before and during consumption of the margarine.. Serum cholesterol concentrations and the ratio of plant sterol to cholesterol decreased after 1 d of consumption of stanol esters (P < 0.05). After 7 d, serum cholesterol decreased by 16% (P < 0.01), cholesterol absorption efficiency decreased by approximately 40%, and fecal output of cholesterol as neutral sterols (but not as bile acids) increased by 36%. Biliary bile acid composition and the molar percentage of biliary cholesterol were unchanged. Increased ratios of cholesterol precursor sterols in serum and bile indicated enhanced cholesterol synthesis during consumption of stanol esters; the percentage absorption of plant sterols and the ratios of plant sterols to cholesterol decreased, whereas serum and biliary plant stanols and their biliary secretion gradually increased. In feces, 95% of cholesterol and 90% of plant stanols were in unesterified form.. In colectomized patients, effective inhibition of cholesterol absorption and lowering of serum cholesterol concentrations and plant sterol ratios occurs within 1 d of the start of consumption of stanol esters. The composition of major bile lipids is unchanged, indicating that gallstone formation is unlikely. Small amounts of plant stanols are recovered in serum and bile during consumption of stanol esters but effectively are secreted through bile, thereby balancing the intake-induced increase in their absorption.

Topics: Adult; Bile Acids and Salts; Biliary Tract; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Cholesterol, VLDL; Colectomy; Feces; Humans; Hypolipidemic Agents; Margarine; Middle Aged; Phospholipids; Phytosterols; Sitosterols; Triglycerides

As part of an extensive safety evaluation programme, a series of studies has been conducted to determine the fate of phytosterols in the rat. Rats were dosed by oral gavage with 14C-labelled samples of cholesterol, beta-sitosterol or beta-sitostanol or (3)H-labelled samples of beta-sitostanol, campesterol, campestanol or stigmasterol dissolved in sunflower seed oil. Urine and faeces were collected for up to 96 hours after dosing. There was no quantification of biliary excreted material in these studies. Animals were sacrificed and either prepared for whole body autoradiography or tissues and carcass remains were assayed for 14C or (3)H. The overall absorption of phytosterols was low as judged by tissue and carcass levels of radioactivity. Elimination from the body was mainly in the faeces and was initially very rapid, but traces of material were still being excreted at 4 days after dosing. While total absorption of the phytosterols could not be fully quantified without biliary excretion data, it was clear that cholesterol was absorbed to the greatest extent (27% of the dose in females at 24 hours). Campesterol (13%) was absorbed more than beta-sitosterol and stigmasterol (both 4%) which were absorbed more than beta-sitostanol and campestanol (1-2%). The absorption of phytosterols was slightly greater in females than males. For each test material, the overall pattern of tissue distribution of radioactivity was similar, with the adrenal glands, ovaries and intestinal epithelia showing the highest levels and the longest retention of radioactivity.

Topics: Animals; Autoradiography; Cholesterol; Female; Intestinal Absorption; Male; Phytosterols; Rats; Sitosterols; Stigmasterol; Tissue Distribution

In recent studies, the life span of stroke-prone spontaneously hypertensive (SHRSP) rats was altered by a variety of dietary fats. It was relatively shorter in rats fed canola oil as the sole source of fat. The present study was performed to find out whether the fatty acid profile and the high content of sulfur compounds in canola oil could modulate the life span of SHRSP rats. SHRSP rats (47 d old, n = 23/group) were matched by body weight and systolic blood pressure and fed semipurified diets containing 10% canola oil, high-palmitic canola oil, low-sulfur canola oil, soybean oil, high-oleic safflower oil, a fat blend that mimicked the fatty acid composition of canola oil, or a fat blend high in saturated fatty acids. A 1% sodium chloride solution was used as drinking water to induce hypertension. After consuming the diets for 37 d, five rats from each dietary group were killed for collection of blood and tissue samples for biochemical analysis. The 18 remaining animals from each group were used for determining their life span. The mean survival time of SHRSP rats fed canola oil (87.4+/-4.0 d) was not significantly different (P > 0.05) from those fed low-sulfur canola oil (89.7+/-8.5 d), suggesting that content of sulfur in canola oil has no effect on the life span of SHRSP rats. The SHRSP rats fed the noncanola oil-based diets lived longer (mean survival time difference was 6-13 d, P < 0.05) than those fed canola and low-sulfur canola oils. No marked differences in the survival times were observed among the noncanola oil-based groups. The fatty acid composition of the dietary oils and of red blood cells and liver of SHRSP rats killed after 37 d of treatment showed no relationship with the survival times. These results suggest that the fatty acid profile of vegetable oils plays no important role on the life span of SHRSP rat. However, phytosterols in the dietary oils and in liver and brain were inversely correlated with the mean survival times,indicating that the differential effects of vegetable oils might be ascribed, at least partly, to their different phytosterol contents.

Topics: Animals; Brain Chemistry; Cholesterol; Dietary Fats, Unsaturated; Fatty Acids; Fatty Acids, Monounsaturated; Hypertension; Liver; Phytosterols; Rapeseed Oil; Rats; Rats, Inbred SHR; Sitosterols; Stroke; Survival Rate; Thiobarbituric Acid Reactive Substances; Vitamin E

As a reference compound library for the investigation of biosynthesis of brassinosteroids, focused on a pathway from campesterol (1) to campestanol (2), 6-oxy functionalized campest-4-en-3-ones as well as campest-5-en-3-one (7) and campestane-3,6-dione were prepared from 1. Oxidation of 1 with pyridinium chlorochromate buffered by calcium carbonate gave 5-en-3-one (7) in 76% yield. Treatment of 7 with silica gel under an oxygen atmosphere in ethyl ether at room temperature produced efficient hydroperoxidation at the C-6 position to give 6alpha-hydroperoxycampest-4-en-3-one and 6beta-hydroperoxycampest-4-en-3-one in 34% and 49% yields, respectively. These compounds were converted to 6alpha-hydroxycampest-4-en-3-one and 6beta-hydroxycampest-4-en-3-one by reduction with triethyl phosphite. This provided the first example of the practical use of hydroperoxidation at C-6 of a Delta(5(6))-unsaturated 3-oxo-steroid with molecular oxygen and silica gel. On the other hand, oxidation of 1 with pyridinium chlorochromate in the absence of calcium carbonate gave campest-4-ene-3,6-dione in 64% yield. This compound was then converted in a highly stereoselective manner to campestane-3,6-dione with A/B trans ring junction by reduction with titanium (III) chloride in 85% yield.

Topics: Biochemistry; Cholesterol; Molecular Structure; Oxygen; Phytosterols; Silica Gel; Silicon Dioxide

The effects of proximal small-bowel resection on absorption and synthesis of cholesterol are unclear.. To study cholesterol absorption and synthesis after proximal gut resections of variable length, plasma plant sterols, cholestanol, and cholesterol precursors were measured 1 and 2 months after 50% and 75% proximal small-bowel resection or transection. To examine the effect of increased crypt cell proliferation and brush border development on cholesterol absorption, the results were related to the mucosal morphology, crypt cell proliferation, and disaccharidase activities of the remaining small bowel.. Campesterol levels in proportion to cholesterol decreased markedly more, and those of cholestanol markedly less, than would be expected simply due to the amount of proximal small intestine removed, whereas sitosterol proportions decreased in proportion to the length of gut resection. Campesterol proportions markedly (P = 0.06) increased between 1 and 2 months after 50% resection but remained unchanged after 75% resection. Crypt cell proliferation was only increased in the 75% resection group (P < 0.05). The longer the proximal gut resection, the lower was the mucosal enzyme activity. Both resection groups showed increased plasma cholesterol precursor proportions and crypt depth (P < 0.05), whereas villus height remained unchanged. After massive proximal resection campesterol and sitosterol proportions were inversely related to crypt cell proliferation (r = -0.86-0.83, P < 0.01).. Increased crypt cell proliferation activated by massive proximal gut resection may act as a previously unrecognized factor in aggravating cholesterol malabsorption and retarding its recovery during the early postoperative period. These findings warrant further investigation.

Topics: Animals; Cell Division; Cholesterol; Disaccharidases; Intestinal Absorption; Intestinal Mucosa; Intestine, Small; Phytosterols; Sitosterols; Swine

Studies considering long-term squalene consumption have revealed no consistent effects on serum cholesterol levels but the immediate effect of dietary squalene on cholesterol synthesis has not been studied. Thus, the effect of a single dose of dietary squalene on postprandial lipid metabolism was studied in 16 male volunteeers aged 22-79 years. Two oral fat meals a week apart were administered to every subject, one without (control) and the other with 500 mg of squalene. Lipids, retinyl palmitate, squalene and non-cholesterol sterols were measured at baseline and after 3, 4, 6, 9, 12 and 24 h postprandially in plasma, chylomicron, VLDL and VLDL bottom and, in six randomly chosen subjects, also in IDL, LDL and HDL. In the fasting samples, squalene was mainly transported in LDL and HDL, whereas in squalene-supplemented postprandium most of squalene was carried in the triglyceride-rich lipoproteins. Postprandial squalene and retinyl palmitate curves closely resembled each other. After the squalene-enriched dietary fat load, squalene was significantly increased compared to control fat loads in plasma, chylomicrons, VLDL and IDL. Squalene addition increased significantly lathosterol/campesterol ratio in chylomicrons and VLDL at 12 h and in VLDL bottom at 9-12 h, and increased significantly VLDL lanosterol/campesterol ratio at 12 h, indicating enhanced cholesterol synthesis caused by squalene. Plasma plant sterol levels remained unchanged. In conclusion, a single oral dose of squalene representing a potential daily dietary amount increases cholesterol synthesis within 9-12 h detected in chylomicrons, VLDL and VLDL bottom.

Topics: Administration, Oral; Adult; Aged; Cholesterol; Chylomicrons; Humans; Lanosterol; Lipoproteins; Male; Middle Aged; Phytosterols; Postprandial Period; Squalene

We measured the percent absorption, turnover, and distribution of campestanol (24-methyl-5alpha-cholestan-3beta-ol) in a sitosterolemic homozygote, her obligate heterozygous mother, and three healthy human control subjects. For reasons relating to sterol hyperabsorption, the homozygote consumed a diet low in plant sterols that contained campestanol at about 2 mg/day. The heterozygote and three control subjects were fed a diet supplemented with a spread that contained campestanol at 540 mg/day and sitostanol (24-ethyl-5alpha-cholestan-3beta-ol) at 1.9 g/day as fatty acid esters. Plasma campestanol concentrations determined by capillary gas-liquid chromatography were 0.72 +/- 0.03 mg/dl in the homozygote, 0.09 +/- 0.04 mg/dl in the heterozygote, and 0.05 +/- 0.03 mg/dl for the control mean. After simultaneous pulse labeling with [3alpha-(3)H]campestanol intravenously and [23-(14)C]campestanol orally, the maximum percent absorption measured by the plasma dual-isotope ratio method as a single time point was 80% in the homozygote, 14.3% in the heterozygote, and 5.5 +/- 4.3% as the mean for three control subjects. Turnover (pool size) values estimated by mathematical analysis of the specific activity versus time [3alpha-(3)H]campestanol decay curves were as follows: 261 mg in the homozygote, 27.3 mg in the heterozygote, and 12.8 +/- 7.6 mg in the three control subjects (homogygote vs. controls, P < 0.001). The calculated production rate (mg/24 h) equivalent to actual absorption in the presence of dietary sterols and stanols was 0.67 mg/day or 31% of intake in the homozygote, 2.1 mg/day or 0.3% of intake in the heterozygote, and 0.7 +/- 0.3 mg/day or 0.1% of intake in the three control subjects. However, the excretion constant from pool A (K(A)) was prolonged markedly in the homozygote, but was 100 times more rapid in the heterozygote and three control subjects.Thus, campestanol, like other noncholesterol sterols, is hyperabsorbed and retained in sitosterolemic homozygotes. However, campestanol absorption was only slightly increased in the sitosterolemic heterozygote and removal was as rapid as in control subjects.

Topics: Adolescent; Adult; Carbon Radioisotopes; Cholesterol; Diet; Female; Half-Life; Heterozygote; Homozygote; Humans; Intestinal Absorption; Kinetics; Lipid Metabolism, Inborn Errors; Male; Middle Aged; Phytosterols; Sitosterols; Tritium

Beta-sitosterol, campesterol and stigmasterol have been known to the phytosterols the most frequently found in plants. Metabolism of phytosterols was investigated using rat feces and liver microsomes. Feces were collected after phytosterols (a well characterized mixture of beta-sitosterol 40%, campesterol 30% and dihydrobrasicasterol) were administered orally (0.5 g/kg) to rats. Metabolites of phytosterols were identified using GC/MS. Three peaks were eluted at 12.47, 12.65, 12.87 min and had characteristic molecular ions m/z 428, 430, 432, respectively. Three fecal metabolites were identified as androstadienedione, androstenedione, and androstanedione. No metabolites could be detected in the rat liver microsomal reaction mixture. The results suggest that the metabolites of phytosterols in rat feces are formed by oxidation at 3- position, saturation at 5- and 6- position, and 17- side chain cleavage in the rat large intestine.

Topics: Animals; Cholesterol; Feces; Gas Chromatography-Mass Spectrometry; In Vitro Techniques; Male; Microsomes, Liver; Phytosterols; Rats; Rats, Sprague-Dawley; Sitosterols

Phytosterols are natural constituents of the human diet, and as part of an extensive programme of safety evaluation studies investigating their use as a novel food ingredient, the possible oestrogenic effects of phytosterols have been investigated using a combination of in vitro and in vivo assays. Competitive binding with the immature rat uterine oestrogen receptor (ER) has been used to measure the ability of phytosterols to bind to ERs while the transcriptional activation of oestrogen-responsive genes has been examined in an oestrogen-inducible yeast screen. Phytosterols did not display any activity in these in vitro assays. Uterotrophic assays have been conducted to investigate the potential for phytosterols to elicit an oestrogenic response when administered orally to immature female rats (n = 10) at doses of 0, 5, 50 or 500 mg/kg/day for 3 consecutive days. Phytosterols (a well characterized mixture of beta-sitosterol, campesterol and stigmasterol) and phytosterol esters (the previous phytosterol mixture esterified with fatty acids from sunflower oil) did not exhibit oestrogenic activity in the immature female rat using uterine wet weight as the endpoint. Beta-oestradiol (0.4 mg/kg/day) consistently produced a significant increase in uterus weights. Coumestrol (a known phytoestrogen) was also tested as a weak positive control and produced a dose response at doses of 20, 40 and 80 mg/kg/day in the uterotrophic assay. In conclusion, we have shown that phytosterols do not bind to the ER and do not stimulate transcriptional activity of the human ER in a recombinant yeast strain. In addition, there was no indication of oestrogenicity from the uterotrophic assay when the material was administered by oral gavage to immature female rats.

Topics: Administration, Oral; Animals; Binding, Competitive; Cholesterol; Coumestrol; Dose-Response Relationship, Drug; Esters; Estradiol; Estrogens, Non-Steroidal; Female; Organ Size; Phytosterols; Rats; Rats, Wistar; Receptors, Estrogen; Saccharomyces cerevisiae; Sitosterols; Stigmasterol; Uterus

Since the isolation and characterization of dwarf1-1 (dwf1-1) from a T-DNA insertion mutant population, phenotypically similar mutants, including deetiolated2 (det2), constitutive photomorphogenesis and dwarfism (cpd), brassinosteroid insensitive1 (bri1), and dwf4, have been reported to be defective in either the biosynthesis or the perception of brassinosteroids. We present further characterization of dwf1-1 and additional dwf1 alleles. Feeding tests with brassinosteroid-biosynthetic intermediates revealed that dwf1 can be rescued by 22alpha-hydroxycampesterol and downstream intermediates in the brassinosteroid pathway. Analysis of the endogenous levels of brassinosteroid intermediates showed that 24-methylenecholesterol in dwf1 accumulates to 12 times the level of the wild type, whereas the level of campesterol is greatly diminished, indicating that the defective step is in C-24 reduction. Furthermore, the deduced amino acid sequence of DWF1 shows significant similarity to a flavin adenine dinucleotide-binding domain conserved in various oxidoreductases, suggesting an enzymatic role for DWF1. In support of this, 7 of 10 dwf1 mutations directly affected the flavin adenine dinucleotide-binding domain. Our molecular characterization of dwf1 alleles, together with our biochemical data, suggest that the biosynthetic defect in dwf1 results in reduced synthesis of bioactive brassinosteroids, causing dwarfism.

Topics: Alleles; Amino Acid Sequence; Arabidopsis; Base Sequence; Brassinosteroids; Cholestanols; Cholesterol; DNA Primers; Genes, Plant; Molecular Sequence Data; Mutation; Phytosterols; Plant Proteins; Sequence Homology, Amino Acid; Steroids, Heterocyclic

In the last several years, attention has been focused on comparing the Western diet, which is rich in fat, protein, and refined carbohydrates, with the Asian diet, which is rich in phytoestrogens, as a possible explanation for the contrasting rates of clinically relevant prostate cancer. Phytoestrogens, plant-derived nutrients, include several isoflavones, flavonoids, lignans, phytosterols, and coumestans, some of which have been postulated as having anticarcinogenic properties. Using a new database, we examined the role of phytoestrogen intake and prostate cancer risk in 83 Caucasian cases and 107 controls. Controls reported consuming higher amounts of foods containing genistein, daidzein, and coumestrol and lower amounts of foods containing campesterol and stigmasterol. Multivariate analysis, after adjustment for age, family history of prostate cancer, alcohol consumption, and total calorie intake, showed an inverse association between coumestrol (p = 0.03) and daidzein (p = 0.07) and prostate cancer risk. Genistein, the most studied phytoestrogen, showed a slight protective effect (p = 0.26). However, a positive association was found between campesterol (p = 0.08) and stigmasterol (p = 0.03) and risk of prostate cancer. These results are suggestive of a possible relationship between phytoestrogen intake and prostate cancer risk. Larger comprehensive studies are needed to further refine the role of phytoestrogen intake in prostate cancer risk.

Topics: Anticarcinogenic Agents; Case-Control Studies; Cholesterol; Databases, Factual; Diet Records; Estrogens, Non-Steroidal; Genistein; Humans; Isoflavones; Male; Middle Aged; Multivariate Analysis; Nutrition Assessment; Phytoestrogens; Phytosterols; Plant Preparations; Prostatic Neoplasms; Risk Factors; Stigmasterol; Surveys and Questionnaires; Texas

Previously, we have shown that the Arabidopsis det2 (deetiolated2) mutant is defective in the biosynthesis of brassinosteroids (BR) and that DET2 (a steroid 5alpha-reductase) acts early in the proposed BR biosynthetic pathway. In this paper we present further biochemical characterization of det2. We have undertaken metabolic experiments with 2H-labeled substrates of intermediates involved in the formation of campestanol from campesterol, and quantitative analysis of intermediates in Arabidopsis wild type and det2. The results of these studies indicate the early operating steps of BR biosynthesis as: campesterol --> 4-en-3beta-ol --> 4-en-3-one --> 3-one --> campestanol in Arabidopsis, with det2 deficient in the conversion of 4-en-3-one to 3-one. We have also detected these intermediates in the formation of campestanol from campesterol and their metabolic conversions using cultured cells of Catharanthus roseus. These studies confirmed the biosynthetic sequence of events from campesterol to campestanol as was found in Arabidopsis. As such, the originally proposed biosynthetic pathway should be modified.

Topics: Arabidopsis; Arabidopsis Proteins; Cholesterol; Culture Techniques; Phytosterols; Plant Proteins; Substrate Specificity

The 5alpha-hydroperoxides of beta-sitosterol, campesterol, stigmasterol, and brassicasterol were obtained by photooxidation of the respective sterols in pyridine in the presence of hematoporphyrine as sensitizer. The reduction of the hydroperoxides gives the corresponding 5alpha-hydroxy derivatives. The 7alpha- and 7beta-hydroperoxides of the sterols were obtained by allowing an aliquot of the 5alpha-hydroperoxides to isomerize to 7alpha-hydroperoxides, which in turn epimerize to 7beta-hydroperoxides. The reduction gave the corresponding 7alpha- and 7beta-hydroxy derivatives. The 5alpha-, 7alpha-, and 7beta-hydroxy derivatives of beta-sitosterol, campesterol, stigmasterol, and brassicasterol were identified by comparing thin-layer chromatography mobilities, specific color reactions, and mass spectral data with those of the corresponding hydroxy derivatives of cholesterol, which were synthesized in the same manner. The phytosterols had the same behavior to photooxidation as cholesterol and, moreover, the different phytosterols photooxidized at about the same rate. The mass spectra of the trimethylsilyl ethers of the hydroxy derivatives of the phytosterols investigated and of the corresponding hydroxy derivatives of cholesterol have the same fragmentation patterns and similar relative ion abundances.

Topics: Cholestadienols; Cholesterol; Gas Chromatography-Mass Spectrometry; Hydroxylation; Mass Spectrometry; Peroxides; Phytosterols; Sitosterols; Stigmasterol

ApoE-deficient mice on low fat diet show hepatic triglyceride accumulation and a reduced very low density lipoprotein (VLDL) triglyceride production rate. To establish the role of apoE in the regulation of hepatic VLDL production, the human APOE3 gene was introduced into apoE-deficient mice by cross-breeding with APOE3 transgenics (APOE3/apoe-/- mice) or by adenoviral transduction. APOE3 was expressed in the liver and, to a lesser extent, in brain, spleen, and lung of transgenic APOE3/apoe-/- mice similar to endogenous apoe. Plasma cholesterol levels in APOE/apoe-/- mice (3.4 +/- 0.5 mM) were reduced when compared with apoe-/- mice (12.6 +/- 1.4 mM) but still elevated when compared with wild type control values (1.9 +/- 0.1 mM). Hepatic triglyceride accumulation in apoE-deficient mice was completely reversed by introduction of the APOE3 transgene. The in vivo hepatic VLDL-triglyceride production rate was reduced to 36% of control values in apoE-deficient mice but normalized in APOE3/apoe-/- mice. Hepatic secretion of apoB was not affected in either of the strains. Secretion of (3)H-labeled triglycerides synthesized from [(3)H]glycerol by cultured hepatocytes from apoE-deficient mice was four times lower than by APOE3/apoe-/- or control hepatocytes. The average size of secreted VLDL particles produced by cultured apoE-deficient hepatocytes was significantly reduced when compared with those of APOE3/apoe-/- and wild type mice. Hepatic expression of human APOE3 cDNA via adenovirus-mediated gene transfer in apoE-deficient mice resulted in a reduction of plasma cholesterol depending on plasma apoE3 levels. The in vivo VLDL-triglyceride production rate in these mice was increased up to 500% compared with LacZ-injected controls and correlated with the amount of apoE3 per particle. These findings indicate a regulatory role of apoE in hepatic VLDL-triglyceride secretion, independent from its role in lipoprotein clearance.

Topics: Animals; Apolipoproteins E; Cells, Cultured; Cholesterol; Crosses, Genetic; Fatty Acids, Nonesterified; Glycerol; Homeostasis; Humans; Lipoproteins; Lipoproteins, VLDL; Liver; Mice; Mice, Knockout; Mice, Transgenic; Microscopy, Immunoelectron; Phytosterols; Sitosterols; Sterols; Triglycerides; Tritium

Incubation of 24 alpha- and 24 beta-methylcholesterols with yeast mutant GL7 afforded their corresponding C-22-desaturated products under the catalysis of sterol delta 22(23)-desaturase. The metabolites were identified to be 22-dehydro-24 alpha-methylcholesterol (2% yield from 24 alpha-methylcholesterol) and 22-dehydro-24 beta-methylcholesterol (51% yield from 24 beta-methylcholesterol) respectively on the basis of their chromatographic and spectral properties. It was concluded that the sterol delta 22(23)-desaturase prefers the 24 beta-methyl sterols and is highly stereospecific.

Topics: Biotransformation; Cholesterol; Chromatography, High Pressure Liquid; Isomerism; Magnetic Resonance Spectroscopy; Mutation; Phytosterols; Saccharomyces cerevisiae

To examine how variable sitostanol (SI) levels in phytosterol-supplemented diets influence plasma and hepatic lipid concentrations, fifty hamsters were divided into five groups and fed semipurified diets containing 0.25% (w/w) cholesterol for 45 days ad libitum. Four groups were fed this diet with 1% (w/w) phytosterol mixtures which contained 0.01% (w/w) SI derived from soybean, 0.2% (w/w) SI derived from tall oil, 0.2% (w/w) synthetic SI mixture (SIM) and 1% (w/w) pure SI, respectively. A control group did not receive phytosterols. Dietary SI supplementation at 1% (w/w) decreased total and non-apolipoprotein-A cholesterol levels in plasma by 34% (P=0.001) and 55% (P=0.04), respectively, whereas mean plasma total cholesterol level in the 0.2% (w/w) SI group was 23% (P=0.001) lower than that of the control group. Conversely, plasma lipid profile in hamsters fed 1 or 0.2% (w/w) SI did not differ from the 0.01% (w/w) SI group. Liver weights were 15 and 20% (P=0.012) higher in the control group compared with those fed 0.01% and 1% (w/w) SI, respectively, while the hepatic cholesterol content in the control group was greater (P<0.0001) than that of all other groups. Plasma campesterol levels were higher (P=0.04) in the 0.01% and 0.2% (w/w) SI fed groups than in the control, 0.2% (w/w) SIM and 1% (w/w) SI groups. Hepatic sitosterol content was elevated (P=0.002) in the SIM fed group compared to other groups. We conclude that dietary SI effect is proportional to its concentration in phytosterol mixtures and in the diet. Dietary SI lowered plasma cholesterol levels at concentrations higher than 0.2% (w/w) in hamsters. (c) 1998 Elsevier Science B.V.

Topics: Animals; Anticholesteremic Agents; Body Weight; Cholesterol; Cholesterol, HDL; Cricetinae; Diet; Eating; Lipids; Liver; Organ Size; Phytosterols; Plant Oils; Sitosterols

To examine whether phytosterols in polyunsaturated oils account for their differential action on lipid metabolism compared with monounsaturated oils, 16 normolipidemic individuals consumed three 10-day experimental diets containing corn oil (high in polyunsaturated fatty acids and phytosterols), olive oil (high in monounsaturated fatty acids and low in phytosterols), or olive oil supplemented with phytosterols given at twice the level naturally found in corn oil (high in monounsaturated fatty acids and phytosterols). Plasma total cholesterol concentrations after both the olive oil and the olive oil-phytosterol treatments were higher (P < 0.001) than those after the corn oil treatment. Olive oil treatment resulted in greater (P < 0.05) plasma LDL-cholesterol and triglyceride concentrations compared to corn oil treatment. Addition of the phytosterol mixture to the olive oil diet resulted in suppression of the significant differences in LDL-cholesterol and triglyceride concentrations between corn and olive oil. Free cholesterol fractional synthetic rates determined by deuterium incorporation were lower (P < 0.05) with olive oil treatment compared to corn oil treatment; the significance of this difference was abolished with the addition of phytosterols to the olive oil diet. These results suggest that phytosterols are partly responsible for the differences in plasma cholesterol levels and synthesis observed between polyunsaturated and monounsaturated oils.

Topics: Adult; Cholesterol; Corn Oil; Dietary Fats, Unsaturated; Energy Intake; Female; Humans; Lipoproteins, LDL; Male; Olive Oil; Phytosterols; Plant Oils; Triglycerides

Contribution of different gut segments to plant sterol absorption, adaptation of plant sterol absorption after partial small bowel resection, and effects of gut transplantation (necessitates extrinsic autonomic denervation and lymphatic disruption) on plant sterol biodynamics are unclear. We studied the consequences of massive proximal small bowel resection and autotransplantation of the remaining ileum on the adaptive absorption and biodynamics of plant sterols. Dietary, fecal, biliary, hepatic and plasma plant sterols, fecal elimination and absorption of cholesterol, small bowel morphology, and intestinal transit were determined before (n = 5) and at 4, 8, and 14 wk after resection of the proximal 75% of the jejunoileum (n = 15) and autotransplantation of the remaining ileum (n = 15) or transection (n = 5). Proximal gut resection significantly reduced cholesterol absorption efficiency; percentage absorption and biliary secretion of plant sterols; plasma, biliary and hepatic campesterol-to-cholesterol proportions; and sitosterol proportions in plasma and bile. Autotransplantation of the remaining ileum further significantly decreased cholesterol absorption efficiency; percentage absorption and biliary secretion of campesterol; campesterol proportions in plasma, bile and liver; and plasma proportions of sitosterol while increasing fecal excretion of neutral and acidic steroids. Plasma proportions of the two plant sterols, but absorption of just campesterol, were gradually improved with increasing cholesterol absorption and villus height after proximal gut resection; the same result was observed to a lesser degree after ileal autotransplantation. In addition, significant positive correlations were found between percentage cholesterol and campesterol absorption and the plasma plant sterol proportions in both proximal resection groups, between campesterol absorption and ileal villus height in the resection group, and between campesterol absorption and intestinal transit time in the autotransplantation group. In conclusion, plasma campesterol and sitosterol closely reflect absorption of cholesterol and plant sterols from intact and autotransplanted ileum during adaptation to proximal gut resection. A loss of proximal gut absorptive surface impairs cholesterol and campesterol absorption more than sitosterol absorption, the latter being apparently less dependent on available jejunal villus surface area.

Topics: Animals; Bile; Cholesterol; Denervation; Feces; Ileum; Intestinal Absorption; Phytosterols; Sitosterols; Swine; Transplantation, Autologous

1. We administered the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor pravastatin at a daily dose of 1 mg kg(-1) body weight to cholesterol-fed (0.03%) heterozygous Watanabe heritable hyperlipidaemic rabbits, an animal model for heterozygous familial hypercholesterolaemia. 2. After 12 months of cholesterol treatment, immunohistochemistry with the monoclonal antibody 9D9 was used to detect hepatic low density lipoprotein (LDL) receptors, which were quantified by densitometry. In addition we determined LDL receptor mRNA by competitive reverse transcriptase polymerase chain reaction. The cholesterol precursor lathosterol and the plant sterol campesterol were analysed by gas-liquid chromatography. 3. The drug reduced total plasma cholesterol levels by 51% (P=0.04), when compared to the control group. Unexpectedly, hepatic LDL receptor density and mRNA showed no significant differences between the groups. Total plasma levels of lathosterol and campesterol also revealed no significant differences between the groups, if expressed relative to plasma cholesterol. 4. The findings suggest that mechanisms other than induced hepatic LDL receptors are responsible for the cholesterol-lowering effect of pravastatin in this animal model. We propose a reduced cholesterol absorption efficiency compatible with similar campesterol levels between both groups observed in our study.

Topics: Animals; Anticholesteremic Agents; Cholesterol; Cholesterol, Dietary; Heterozygote; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hyperlipoproteinemia Type II; Immunohistochemistry; Intestinal Absorption; Liver; Phytosterols; Polymerase Chain Reaction; Pravastatin; Rabbits; Receptors, LDL; RNA, Messenger

In the present pilot study, for investigating the physiological effects of different types of nondigestible oligosaccharides, we have validated the application of methodologies for the analysis of bile acids and neutral steroids in feces of human subjects. The accuracy of the extraction and chromatographic procedures for the analyses of bile acids and neutral steroids was determined by recovery of added compounds to fecal homogenate. The precision of the above procedures was checked by analyzing these compounds in samples (n = 5) of the same fecal homogenate. Recoveries of added bile acids ranged from 86 and 96%, and those of neutral steroids varied from 81 to 97%. The precision expressed as coefficients of variation of bile acids and neutral steroids ranged from 2.3 to 8.3% and from 6.3 to 11.8%, respectively. The intra- and interindividual variabilities expressed as coefficients of variation of bile acids varied from 1 to 58 and from 0 to 74%, respectively. The same variabilities for neutral steroids ranged from 0.5 to 107% and from 1 to 168%, respectively. The methods validated in the present pilot study were adequate for applying to our forthcoming European Union coordinated major study on the physiological effects of different types of nondigestible oligosaccharides and involving large numbers of samples.

Topics: Bile Acids and Salts; Cholestanol; Cholesterol; Chromatography, Gas; Feces; Humans; Phytosterols; Sensitivity and Specificity; Sitosterols; Steroids; Stigmasterol

We have identified the function of the Arabidopsis DIMINUTO/DWARF1 (DIM/DWF1) gene by analyzing the dim mutant, a severe dwarf with greatly reduced fertility. Both the mutant phenotype and gene expression could be rescued by the addition of exogenous brassinolide. Analysis of endogenous sterols demonstrated that dim accumulates 24-methylenecholesterol but is deficient in campesterol, an early precursor of brassinolide. In addition, we show that dim is deficient in brassinosteroids as well. Feeding experiments using deuterium-labeled 24-methylenecholesterol and 24-methyldesmosterol confirmed that DIM/DWF1 is involved in both the isomerization and reduction of the Delta24(28) bond. This conversion is not required in cholesterol biosynthesis in animals but is a key step in the biosynthesis of plant sterols. Transient expression of a green fluorescent protein-DIM/DWF1 fusion protein and biochemical experiments showed that DIM/DWF1 is an integral membrane protein that most probably is associated with the endoplasmic reticulum.

Topics: Amino Acid Sequence; Arabidopsis; Arabidopsis Proteins; Base Sequence; Brassinosteroids; Cholestanols; Cholesterol; DNA, Plant; Gene Expression Regulation, Plant; Genes, Plant; Membrane Proteins; Molecular Sequence Data; Mutation; Phenotype; Phytosterols; Plant Growth Regulators; Plant Proteins; RNA, Messenger; RNA, Plant; Sequence Homology, Amino Acid; Steroids; Steroids, Heterocyclic; Stigmasterol

Higher plants synthesize 24-methyl sterols and 24-ethyl sterols in defined proportions. As a first step in investigating the physiological function of this balance, an Arabidopsis cDNA encoding an S-adenosyl-L-methionine 24-methylene lophenol-C24(1)-methyltransferase, the typical plant enzyme responsible for the production of 24-ethyl sterols, was expressed in tobacco (Nicotiana tabacum L.) under the control of a constitutive promoter. Transgenic plants displayed a novel 24-alkyl-Delta5-sterol profile: the ratio of 24-methyl cholesterol to sitosterol, which is close to 1 in the wild type, decreased dramatically to values ranging from 0.01 to 0.31. In succeeding generations of transgenic tobacco, a high S-adenosyl-L-methionine 24-methylene lophenol-C24(1)-methyltransferase enzyme activity and, consequently, a low ratio of 24-methyl cholesterol to sitosterol, was associated with reduced growth compared with the wild type. However, this new morphological phenotype appeared only below the threshold ratio of 24-methyl cholesterol to sitosterol of approximately 0.1. Because the size of cells was unchanged in small, transgenic plants, we hypothesize that a radical decrease of 24-methyl cholesterol and/or a concomitant increase of sitosterol would be responsible for a change in cell division through as-yet unknown mechanisms.

Topics: Arabidopsis; Base Sequence; Cholesterol; Cloning, Molecular; DNA Primers; DNA, Complementary; Methyltransferases; Nicotiana; Phytosterols; Plants, Genetically Modified; Plants, Toxic; Sitosterols

Unesterified cholesterol (UC) that is taken up by the liver from lipoproteins is rapidly mixed by exchange with liver UC. Thus, it is not possible to quantitate the transport of UC from different lipoproteins into bile using radiolabeled UC. However, plant sterols do not exchange with UC and are secreted in bile with the same kinetics as UC. To compare the contribution to bile of sterols from different lipoproteins, we perfused isolated rat livers with VLDL, LDL, and HDL that were obtained from patients with hereditary phytosterolemia and were rich in plant sterols. After 30-min recirculating perfusions, hepatic concentrations of plant sterols were not different after different lipoproteins were perfused. However, biliary plant sterol secretion was markedly different: with the perfusion of either VLDL or LDL there was no increase in plant sterols in bile, but with perfusion of HDL, the secretion of plant sterols was increased two- to threefold (P = 0.0005). The increase in biliary plant sterols was detected 5-10 min after HDL was added to perfusates and was similarly large for each of three individual plant sterols that was tracked. Results show that when sterol transport from lipoproteins into bile can be determined, only HDL provides a vehicle for UC elimination in bile that is consistent with its putative function in reverse cholesterol transport.

Topics: Animals; Bile; Biological Transport; Cholesterol; Chromatography, High Pressure Liquid; Humans; Hypolipoproteinemias; Lipoproteins, HDL; Lipoproteins, LDL; Lipoproteins, VLDL; Liver; Male; Perfusion; Phytosterols; Rats; Rats, Sprague-Dawley; Sitosterols

Cholesterol and lipoprotein metabolism was studied in mildly hypercholesterolemic nonobese men with NIDDM to find out which metabolic parameters regulate serum cholesterol level in these NIDDM subjects.. Nonobese NIDDM subjects (n = 13) and control subjects (n = 18) with serum cholesterol > or = 6.0 and triglycerides < or = 2.5 mmol/l were studied on a similar monoene-enriched diet. Cholesterol absorption was studied with peroral double isotopes and by measuring serum plant sterols with gas-liquid chromatography; cholesterol synthesis was studied by measuring sterol balance and by measuring serum cholesterol precursor sterols; and LDL kinetics was measured with 131I-labeled autologous apoprotein (apo) B.. Cholesterol absorption was significantly lower in NIDDM subjects than in the control subjects, as detected by low serum plant sterol levels and absorption percentage (23 vs. 29%, P < 0.05). Cholesterol synthesis was significantly higher in NIDDM subjects than in the control subjects, as detected by precursor sterols or balance data (18 vs. 12 mg.kg-1.day-1, P < 0.01), cholesterol turnover (19 vs. 13 mg.kg-1.day-1, P < 0.01), and LDL apo B removal (0.343 vs. 0.267 pools/day, P < 0.01). Serum total and LDL cholesterol levels were inversely correlated with cholesterol synthesis, which was positively related to the catabolism of LDL apo B and negatively related to cholesterol absorption efficiency.. In this small selected group of mildly hypercholesterolemic nonobese NIDDM subjects, the regulation of serum cholesterol levels was achieved by the homeostasis between cholesterol absorption, synthesis, and LDL fractional catabolism. Cholesterol turnover and removal of LDL apo B were high in NIDDM subjects, compared with the control subjects, whereas cholesterol absorption efficiency was abnormally low Because of the relatively small number of selected subjects, the present results are not directly applicable to the overall NIDDM population.

Topics: Absorption; Apolipoproteins B; Bile Acids and Salts; Cholesterol; Cholesterol, Dietary; Cholesterol, LDL; Diabetes Mellitus, Type 2; Dietary Fats; Humans; Hypercholesterolemia; Lipids; Male; Middle Aged; Phytosterols; Reference Values

CaCo-2 cells were used to address the effect of the plant sterol, beta-sitosterol, on cholesterol trafficking, cholesterol metabolism, and apoB secretion. Compared to cells incubated with micelles (5 mM taurocholate and 250 microM oleic acid) containing cholesterol, which caused an increase in the influx of plasma membrane cholesterol to the endoplasmic reticulum and increased the secretion of cholesteryl esters derived from the plasma membrane, beta-sitosterol did not alter cholesterol trafficking or cholesteryl ester secretion. Including beta-sitosterol in the micelle together with cholesterol attenuated the influx of plasma membrane cholesterol and prevented the secretion of cholesteryl esters derived from the plasma membrane. Stigmasterol and campesterol had effects similar to beta-sitosterol, although campesterol did not promote a modest influx of plasma membrane cholesterol. Including beta-sitosterol in the micelle with cholesterol decreased the uptake of cholesterol. Compared to cholesterol, 60% less beta-sitosterol was taken up by CaCo-2 cells. No observable esterification of beta-sitosterol was appreciated and the transport of the plant sterol to the basolateral medium was negligible. Cholesterol synthesis and HMG-CoA reductase activities were decreased in cells incubated with beta-sitosterol. This was associated with a decrease in reductase mass and mRNA levels. Cholesteryl ester synthesis and ACAT activities were unaltered by beta-sitosterol. Both stigmasterol and campesterol decreased reductase activity, but only campesterol increased ACAT activity. beta-sitosterol did not affect the secretion of apoB mass. The results suggest that beta-sitosterol does not promote cholesterol trafficking from the plasma membrane to the endoplasmic reticulum. beta-sitosterol interferes with the uptake of micellar cholesterol causing less plasma membrane cholesterol to influx and less cholesteryl ester to be secreted. Despite its lack of effect on cholesterol trafficking, beta-sitosterol decreases cholesterol synthesis at the level of HMG-CoA reductase gene expression.

Topics: Caco-2 Cells; Cell Membrane; Cholesterol; Cholesterol Esters; Esterification; Humans; Hydroxymethylglutaryl CoA Reductases; Intestinal Mucosa; Intestines; Micelles; Oleic Acid; Phytosterols; Sitosterols; Sterol O-Acyltransferase; Stigmasterol; Taurocholic Acid; Time Factors

The Arabidopsis DEETIOLATED2 (DET2) gene has been cloned and shown to encode a protein that shares significant sequence identity with mammalian steroid 5 alpha-reductases. Loss of DET2 function causes many defects in Arabidopsis development that can be rescued by the application of brassinolide; therefore, we propose that DET2 encodes a reductase that acts at the first step of the proposed biosynthetic pathway--in the conversion of campesterol to campestanol. Here, we used biochemical measurements and biological assays to determine the precise biochemical defect in det2 mutants. We show that DET2 actually acts at the second step in brassinolide biosynthesis in the 5 alpha-reduction of (24R)-24-methylcholest-4-en-3-one, which is further modified to form campestanol. In feeding experiments using 2H6-labeled campesterol, no significant level of 2H6-labeled campestanol was detected in det2, whereas the wild type accumulated substantial levels. Using gas chromatography-selected ion monitoring analysis, we show that several presumed null alleles of det2 accumulated only 8 to 15% of the wild-type levels of campestanol. Moreover, in det2 mutants, the endogenous levels of (24R)-24-methylcholest-4-en-3-one increased by threefold, whereas the levels of all other measured brassinosteroids accumulated to < 10% of wild-type levels. Exogenously applied biosynthetic intermediates of brassinolide were found to rescue both the dark- and light-grown defects of det2 mutants. Together, these results refine the original proposed pathway for brassinolide and indicate that mutations in DET2 block the second step in brassinosteroid biosynthesis. These results reinforce the utility of combining genetic and biochemical analyses to studies of biosynthetic pathways and strengthen the argument that brassinosteroids play an essential role in Arabidopsis development.

Topics: 3-Oxo-5-alpha-Steroid 4-Dehydrogenase; Arabidopsis; Arabidopsis Proteins; Brassinosteroids; Cholestanols; Cholesterol; Deuterium; Mutation; Phenotype; Phytosterols; Plant Proteins; Steroids; Steroids, Heterocyclic

The sterol composition of 42 fungal species representing six of the eight orders of the Zygomycota was determined using gas-liquid chromatography-mass spectrometry to assess whether the distribution of major sterols in this phylum has taxonomic or phylogenetic relevance. Ergosterol, 22-dihydroergosterol, 24-methyl cholesterol, cholesterol, and desmosterol were detected as the major sterols among the species studied. Ergosterol was the major sterol of the Dimargaritales, Zoopagales, and 13 of the 14 Mucorales families included in this study. Desmosterol appeared to be the characteristic sterol of the Mortierellaceae (Mucorales), 24-Methyl cholesterol was the major sterol of the Entomophthorales genera Entomophthora, Conidiobolus and Basidiobolus, but cholesterol was the sole sterol detected in Delacroixia coronatus. The Kickxellales species analyzed in this study were characterized by 22-dihydroergosterol as the major sterol. These results suggest that certain orders of the Zygomycota may be distinguished on the basis of major sterol. Also, if sterol structure has phylogenetic implications, then orders might be arranged in the order Kickxellales (C28 delta 5,7)-->Dimargaritales, Zoopagales and Mucorales (C28 delta 5,7,22) on the basis of evolution of the predominant and presumably most competent sterol, ergosterol. Although the Entomophthorales would be expected to be more primitive than the above orders based on the predominance of C28 delta 5, it is not apparent from these data that members of the Zygomycota with ergosterol or its precursors as major sterols evolved from this taxon or the Chytridiomycota.

Topics: Cholesterol; Desmosterol; Ergosterol; Evolution, Molecular; Fungi; Gas Chromatography-Mass Spectrometry; Molecular Structure; Phylogeny; Phytosterols; Sterols

Topics: Animals; Cholesterol; Graft Survival; Ileum; Isomerism; Phytosterols; Sterols; Swine; Time Factors; Transplantation, Autologous

Absorption of dietary cholesterol, campesterol, and sitosterol, cholesterol balance, and fecal excretion of plant sterols were determined in three unrelated patients with phytosterolemia and three healthy volunteers during constant intake of cholesterol and plant sterols using accurate gas-liquid chromatography-mass spectrometry techniques. Each subject received a mixture of [26,26,26,27,27,27-2H6]cholesterol, [6,7,7-2H3]sitostanol, and [6,7,7-2H3]campesterol together with two non-absorbable markers, [5,6,22,23-2H4]sitostanol and chromic oxide. Feces were collected from days 5 to 7 and absorption of different sterols was calculated from the intestinal disappearance of the different sterols relative to [5,6,22,23-2H4]sitostanol and chromic oxide. The results obtained by the two markers were not different and the absorption of cholesterol averaged 53 +/- 4% for the patients (mean +/- SD) and 43 +/- 3% for the volunteers. Campesterol absorption averaged 24 +/- 4% in patients and 16 +/- 3% in healthy volunteers, whereas sitosterol absorption averaged 16 +/- 1% and 5 +/- 1%, respectively. Cholesterol synthesis expressed by body weight varied considerably in the two groups but appeared to be about 5 times lower in patients than in controls. Administration of a high dose of sitostanol (0.5 g t.i.d.) to two patients was followed by a reduction in cholesterol absorption by 24% and 44%, an increase in fecal output of cholesterol and steroids derived from cholesterol and plant steroids, and a marked reduction of serum cholesterol, campesterol, and sitosterol. Under the conditions used, inhibition of cholesterol absorption by sitostanol was not followed by a significant rise in cholesterol synthesis. The time of observation was, however, too short to allow final conclusion on this. The results show that the absolute difference in absorption rate of different sterols between the patients and healthy volunteers was about the same. As a consequence, increasing hydrophobicity causes a relative decrease of absorption rates. Thus, patients with phytosterolemia seem to have a generally increased absorption of sterols rather than a loss of a specific discriminatory mechanism, and oral administration of sitostanol seems to be an interesting new approach for treatment of phytosterolemia.

Topics: Absorption; Adult; Anticholesteremic Agents; Bile Acids and Salts; Cholesterol; Cholesterol, Dietary; Deuterium; Dietary Fats; Feces; Female; Humans; Intestinal Mucosa; Lipid Metabolism, Inborn Errors; Lipoproteins; Male; Middle Aged; Phytosterols; Sitosterols; Steroids; Sterols

7-Ketocholesterol (a major cholesterol oxidation product) and phytosterols are important indicators of lipoprotein oxidation and lipoprotein metabolism respectively. We describe a simple, sensitive and reproducible method for the simultaneous measurement of these sterols in human lipoprotein samples by capillary column gas liquid chromatography. The method is suitable for clinical studies as small quantities of lipoprotein are required. Sterols are analysed after extraction from lipoprotein samples obtained by sequential flotation ultracentrifugation. The method involves briefly: extraction from lipoprotein samples using chloroform-methanol, saponification of sterol esters using cold potassium hydroxide, purification and derivatisation to trimethylsilyl ethers using BSTFA and 1% TMCS. Oxidation is prevented by drying under nitrogen and the use of powerful antioxidants. Separation is achieved using a DB-1 capillary column and a two-stage temperature ramp from 180-250 degrees C and detection using FID. The identity of sterols can be confirmed by GC-MS. Phytosterols and 7-ketocholesterol are present at low concentration in all the major lipoproteins. Using [3,4-13C]cholesterol and GC-MS we present evidence that cholesterol oxidation does not occur during the processing of lipoproteins using this technique.

Topics: Capillary Action; Cholesterol; Chromatography, Gas; Humans; Ketocholesterols; Lipoproteins; Male; Oxidation-Reduction; Phytosterols; Reproducibility of Results; Sitosterols

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.

Topics: Animals; Anticholesteremic Agents; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Dietary Fats, Unsaturated; Drug Interactions; Eating; Glycine max; Liver; Male; Phytosterols; Plant Oils; Rats; Rats, Wistar; Sitosterols; Structure-Activity Relationship

Aloe vera at doses of 100 and 300 mg/kg daily for 4 days blocked the wound healing suppression of hydrocortisone acetate up to 100% using the wound tensile strength assay. This response was because of the growth factors present in A. vera masking the wound healing inhibitors such as sterols and certain amino acids. The sterols showed good anti-inflammatory activity (-36%) in reducing the croton oil-induced ear swelling. This activity displayed a dose-response relationship.

Topics: Aloe; Animals; Cholesterol; Croton Oil; Dose-Response Relationship, Drug; Drug Therapy, Combination; Ear; Hydrocortisone; Labyrinthitis; Male; Mice; Mice, Inbred ICR; Pentacyclic Triterpenes; Phytosterols; Plants, Medicinal; Sitosterols; Tensile Strength; Triterpenes; Wound Healing

Quantitative analysis of the local distribution of four noncholesterol sterols, 24-methylene cholesterol, campesterol, stigmasterol, and beta-sitosterol, and of the local distribution of cholesterol in gallstones was performed by mass spectrometry, with D6-cholesterol as an internal standard. The role played by trace amounts of these four noncholesterol sterols in the formation of gallstones was investigated by comparing the amounts of these sterols in different parts of gallstones. It was found that the amounts of the noncholesterol sterols in the inside part were significant greater than the amounts in the outside part of various structural types of gallstones. However, the distribution of the cholesterol did not show such variation. The amounts of noncholesterol sterols distributed locally suggested that these sterols play a role in the formation of gallstones.

Topics: Cholelithiasis; Cholesterol; Female; Gas Chromatography-Mass Spectrometry; Humans; Male; Middle Aged; Phytosterols; Sitosterols; Sterols; Stigmasterol

A number of neutral marine steroids such as desmosterol, campesterol, brassicasterol, gorgosterol, and other trace steroids were isolated from the coelomic fluid of ripe Nereis succinea and checked for biological activity as sex pheromones on swarming specimens of Platynereis dumerilii and Nereis succinea. No significant influence of synthetic gorgosterol or a natural extract of gorgosterol or the other identified steroids on the swarming behavior was observed.

Topics: Animals; Cholestadienols; Cholesterol; Desmosterol; Phytosterols; Polychaeta; Sex Attractants; Sexual Behavior, Animal; Steroids

Intestinal absorption of cholesterol, campesterol, campestanol, stigmasterol and sitosterol were measured in 10 healthy subjects by an intestinal perfusion technique over a 50 cm segment of the upper jejunum using sitostanol as non-absorbable marker. Cholesterol absorption was highest and averaged 33%., whereas the absorption rate of sitosterol averaged 4.2% and of stigmasterol 4.8%. Higher absorption rates were found for campesterol (9.6%). Campestanol, the 5 alpha saturated derivative of campesterol, showed the highest absorption rate (12.5%) of all plant sterols. A positive correlation between the absorption rate of cholesterol and campesterol was established. In addition, there was a negative correlation between the ratio of sitosterol to cholesterol and the mass of cholesterol absorption. These results are in agreement with previous observations in animal studies, namely, that increasing the length of the side-chain of cholesterol decreases the absorbability of the sterol. Surprisingly, campestanol, the 5 alpha saturated derivate of campesterol, was shown to have higher absorbability compared with its unsaturated compound. This finding is in contrast to previous assumptions, that hydrogenisation of the nucleus double bond of a sterol causes a decrease of absorbability, as has been demonstrated for cholesterol/cholestanol and sitosterol/sitostanol.

Topics: Cholesterol; Humans; Intestinal Absorption; Male; Perfusion; Phytosterols; Sitosterols

This study was undertaken to compare the ability of two plant sterols to reduce serum levels of lipids and to compare their mechanism of action in nine children with severe familial hypercholesterolemia (total and low-density lipoprotein cholesterol concentrations averaged 9.57 mmol/L (370 mg/dl) and 7.87 mmol/L (301 mg/dl)). After a 3-month strict diet, the children were given sitosterol pastils (2 gm three times a day) for 3 months, followed by a 7-month course of sitostanol (0.5 gm three times a day). Serum lipoprotein levels and serum concentrations of campesterol and sitosterol were determined in all nine children, and the fecal excretion of neutral and acidic sterols were determined in seven children at the end of each therapeutic regimen. Sitosterol reduced low-density lipoprotein cholesterol levels by 20% (p < 0.01); sitostanol reduced low-density lipoprotein cholesterol levels by 33% after 3 months and 29% after 7 months (p < 0.01 compared with diet; p < 0.05 compared with sitosterol). Although sitosterol did not alter serum concentrations of campesterol and sitosterol, a significant reduction did occur during sitostanol therapy (-47% and -51%, respectively; p < 0.01). Fecal excretion of neutral sterols increased from 6.7 mg/kg per day during the control period to 9.7 mg/kg per day during sitosterol administration (p < 0.05), and to 12.6 mg/kg per day during sitostanol administration (p < 0.05 compared with diet and sitosterol periods), indicating an increase in the inhibition of intestinal cholesterol absorption. All children completed the study and no obvious side effects occurred. The data indicate that sitostanol, even with a dose four-fold lower than that of sitosterol, was significantly more effective in reducing elevated levels of low-density lipoprotein cholesterol, and the reduction in serum lipid levels was of the same magnitude as that observed with systemic lipid-lowering drugs. These results suggest that sitostanol, a nonabsorbable plant sterol, could be the drug of choice for treating familial hypercholesterolemia in childhood.

Topics: Adolescent; Alanine Transaminase; Alkaline Phosphatase; Apolipoproteins B; Carotenoids; Child; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Feces; Female; Heterozygote; Humans; Hyperlipoproteinemia Type II; Male; Phytosterols; Sitosterols; Sterols

Proportions of cholesterol precursors (squalene, delta 8-cholestenol, desmosterol and lathosterol), plant sterols (campesterol and sitosterol) and cholestanol to cholesterol in serum were measured before and serially after liver transplantation in eight patients with primary biliary cirrhosis (PBC) and three with acute liver necrosis. The preoperative proportions of cholestanol were 12 and 3-times higher in the PBC and necrosis groups, respectively, than in a control group of 27 individuals, while those of lathosterol were low in both groups and the campesterol/sitosterol ratio in the PBC group. During the operation the proportions of cholestanol fell sharply and those of lathosterol rose especially in the PBC group. During the postoperative follow-up of 5 weeks the proportions of the non-cholesterol sterols were markedly improved especially in the necrosis group yet those of cholestanol remained high and the campesterol/sitosterol ratios low, particularly in the PBC group. The proportions of lathosterol increased gradually almost to the control limits within the postoperative 5-week period, whereas those of desmosterol decreased. The non-cholesterol sterol values were not related to acute rejections, while significant correlations of cholestanol to liver function tests was found especially at the end of the follow-up.

Topics: Acute Disease; Adult; Cholestanol; Cholesterol; Female; Humans; Liver Cirrhosis, Biliary; Liver Diseases; Liver Transplantation; Male; Middle Aged; Necrosis; Phytosterols; Protein Precursors; Sitosterols; Squalene

Rapeseed oil fed to 24 hypercholesterolemic patients (50 g/day) reduced serum cholesterol (-8.5%) and cholestanol concentrations but increased those of campesterol and sitosterol. Continuation of rapeseed oil alone or with added sitosterol (625 mg/day) or sitostanol (630 mg/day) had no further effect on serum cholesterol. Rapeseed oil with sitosterol increased further its own proportion to cholesterol in serum but reduced that of campesterol while rapeseed oil with sitostanol reduced the proportions of both sitosterol and campesterol proportionately to the pretreatment values. The changes in the campesterol and sitosterol proportions were negatively and positively related to each other during the sitosterol and sitostanol additions, respectively. Thus, concentrations of unsaturated plant sterols in serum reflect their dietary intakes, saturated plant sterols are virtually not absorbed, plant sterols interfere with absorption of unsaturated structurally different plant sterols and cholestanol, and plant sterol-induced reduction of sterol absorption may be positively related to absorption efficiency of sterols.

Topics: Adult; Body Weight; Brassica; Cholesterol; Dietary Fats; Female; Humans; Hypercholesterolemia; Male; Middle Aged; Phytosterols; Plant Oils; Sitosterols

Topics: Bilirubin; Biomarkers; Cholesterol; Female; Humans; Liver Cirrhosis, Biliary; Liver Diseases; Liver Transplantation; Male; Phytosterols; Reference Values; Sitosterols

Plasma plant sterol concentrations (an index of cholesterol absorption efficiency) and plasma lathosterol concentration (an index of cholesterol synthesis rate) were measured in 52 patients with non-insulin dependent diabetes mellitus (NIDDM) and 36 non-diabetic controls. Plasma plant sterol concentrations were significantly (P less than 0.01) lower in diabetic patients (campesterol: men -36%, women -48%; betasitosterol: men -35%, women -42%). Fasting serum insulin levels were inversely correlated with plasma plant sterol concentrations in diabetic patients (campesterol: r = -0.347, P = 0.012; betasitosterol: r = -0.345, P = 0.012) and in non-diabetic men (campesterol: r = -0.578, P = 0.039; betasitosterol: r = -0.702, P = 0.008). Serum insulin levels were also correlated significantly with plasma lathosterol concentration in diabetic patients (r = 0.295, P = 0.034). The results of this study suggest that absorption of plant sterols and possibly cholesterol from the diet may be reduced in hyperinsulinemic diabetics.

Topics: Adult; Aged; Cholesterol; Diabetes Mellitus, Type 2; Female; Humans; Insulin; Male; Middle Aged; Phytosterols; Sitosterols

The hypocholesterolaemic effect of pravastatin 40 mg and lovastatin 40 mg daily has been compared in patients with familial hypercholesterolaemia (FH). Administration of the two drugs was separated by a three-month washout period. The reduction in total serum cholesterol after 1,2 and 4 weeks of treatment was similar after pravastatin (-23%, -32% and -32%) and lovastatin (-23%, -30% and -31%). The serum concentrations of LDL cholesterol were similarly reduced, whilst triglycerides, other lipoproteins, cholestanol and squalene were not altered. The reductions in the serum levels of the cholesterol precursor sterols, delta 8-cholesterol, desmosterol and lathosterol were not significantly different after either drug. The lack of difference suggests that cholesterol synthesis was equally inhibited by the two agents. In addition, the serum content of the plant sterols campesterol and sitosterol tended to be equally increased. The comparability of the increases suggests that the absorption and biliary elimination of the two sterols were equally affected by the two statins. Thus, no difference was found between the effects of pravastatin and lovastatin on the serum levels and metabolic precursors of cholesterol in FH during four weeks of treatment.

Topics: Adult; Aged; Cholesterol; Cholesterol, LDL; Desmosterol; Female; Humans; Hyperlipoproteinemia Type II; Isomerism; Lovastatin; Male; Middle Aged; Phytosterols; Pravastatin; Sitosterols; Triglycerides

A potential in vitro cell culture model was developed for studies concerning the pathological effect of phytosterolemia in which liposomal phytosterols were incorporated into human skin fibroblasts and hepatoblastoma (HepG2) cells. After incubation with phytosterols, fibroblasts and HepG2 cells contained a significant amount (20-27%) of phytosterols (campesterol and beta-sitosterol). Phytosterol accumulation caused a significant reduction in the cholesterol content of cells. Labeled sitosterol and cholesterol showed similar uptake with lower esterification of sitosterol when compared to cholesterol. Labeled sitosterol incorporated into LDL was esterified to a greater extent than sitosterol added as straight liposome. About 23% of the labeled sitosterol was converted into acidic products and 5.6% was present as 5 alpha-stanols in HepG2 cells.

Topics: Cells, Cultured; Cholesterol; Fibroblasts; Humans; Liposomes; Models, Biological; Phytosterols; Sitosterols; Skin; Tumor Cells, Cultured

We measured the serum lathosterol level, a reflection of the rate of whole body cholesterol synthesis, in 15 patients with manifest type III hyperlipoproteinemia (HLP), in 20 subjects with apolipoprotein (apo) E2/2 phenotype, but without type III HLP, in 21 patients with type IIA and 10 patients with type IIB HLP. A group of 100 subjects with apo E3/3 phenotype served as reference. Using ANCOVA, lathosterol was adjusted for serum cholesterol and triglyceride concentrations, since these parameters were found to independently correlate with lathosterol. The adjusted means (+/- SEM), in mumol/L, in these groups were 12.9 +/- 1.1, 8.2 +/- 1.1, 4.8 +/- 0.9, 9.8 +/- 1.4, and 7.8 +/- 0.4, respectively. Type III HLP patients had significantly higher lathosterol levels than all other groups except type IIB HLP. In addition, lathosterol was significantly lower in type IIA patients than in all other groups. The serum levels of plant sterols, used as a reflection of cholesterol absorption, did not differ among the various groups after adjustment for serum cholesterol. These findings suggest that an overproduction of cholesterol is one factor discriminating E2/2 homozygotes with type III HLP from those without the disease.

Topics: Analysis of Variance; Apolipoprotein E2; Apolipoproteins E; Cholesterol; Humans; Hyperlipoproteinemia Type II; Hyperlipoproteinemia Type III; Isomerism; Phenotype; Phytosterols; Sitosterols

Serum levels of cholesterol precursors (squalene, delta 8-cholestanol, desmosterol and lathosterol), plant sterols (campesterol and sitosterol), cholestanol and cholestanol/noncholesterol sterol ratios were related to liver damage and liver transplantation indications in healthy controls (n = 26) and in 31 patients with primary biliary cirrhosis divided into group I (S-bilirubin less than 21 mumol/L; n = 14), group II (S-bilirubin 21 to 108 mumol/L; n = 7) and group III (elected for liver transplantation; S-bilirubin 109 to 520 mumol/L; n = 10). The mean serum respective lathosterol levels in controls and in group I were three and two times higher than those in groups II and III, respectively. The plant sterol contents were higher in group II than in groups I and III and the campesterol/sitosterol ratios were lowest in group III. The serum cholestanol levels were high even in group I (i.e., in patients without icterus) and increased progressively to group III, up to 6 and 13 times those in group I and the control group, respectively. The cholestanol/noncholesterol sterol ratios increased progressively from the controls to groups I, II and III. The serum cholestanol levels were positively related to serum bilirubin levels in all primary biliary cirrhosis patients (n = 31, r = 0.906) and to the plant sterol levels in the control group and group I, but significantly negatively in group III. The cholestanol vs. precursor sterol correlations were negative in most cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Cholestanol; Cholesterol; Female; Humans; Liver Cirrhosis, Biliary; Liver Function Tests; Liver Transplantation; Male; Phytosterols; Sitosterols; Sterols

Topics: Cholesterol; Chromatography, Gas; Food, Fortified; Humans; Phytosterols; Sitosterols; Stigmasterol

We measured the cholestanol, cholesterol precursor (lathosterol), and plant sterol (campesterol and sitosterol) concentrations of serum and bile in 11 patients with cerebrotendinous xanthomatosis. The mean values of serum cholestanol, lathosterol, campesterol, and sitosterol were, respectively, 8.4-, 2.5-, 2.7-, and 1.4-times higher in the patients than in normal control subjects (n = 26). Cholestanol (6.7-fold) and campesterol (3.7-fold) levels in bile (n = 4) were also elevated in the patients. There was no significant difference of serum sterol levels between patients with coronary artery disease and those without it. Chenodeoxycholic acid treatment for periods ranging from 6 months to 3 years and 4 months lowered serum lathosterol (57.7% reduction) and campesterol (57.8%) levels in parallel with cholestanol (70.8%) level, but the sitosterol level (19.7%) decreased less. Thus, increased levels of cholesterol precursor (lathosterol), plant sterols (campesterol and sitosterol), and cholestanol were found in the serum and bile in cerebrotendinous xanthomatosis. Chenodeoxycholic acid treatment effectively reduced the levels of these sterols, except for sitosterol.

Topics: Adult; Bile; Chenodeoxycholic Acid; Cholestanol; Cholesterol; Chromatography, High Pressure Liquid; Coronary Disease; Female; Humans; Male; Middle Aged; Phytosterols; Sitosterols; Xanthomatosis

The typical plant sterols (sitosterol, stigmasterol and campesterol) were compared with respect to their ability to regulate membrane fluidity of soybean phosphatidylcholine (PC) vesicles. Fluidity changes were monitored by the steady-state fluorescence anisotropy with 1,6-diphenyl-1,3,5-hexatriene as a probe and assigned to a measure of the acyl chain orientational order. Sitosterol and campesterol appear to be the most suitable sterols in ordering the acyl chains of soybean lecithin bilayers, even more efficient than cholesterol, the standard of reference for sterol effects on membranes, suggesting that they play a significant role in the regulation of plant membrane properties. Stigmasterol is shown to be much less active. Cycloartenol, a biosynthetic precursor of plant sterols, increases the acyl chain order with the same efficiency as cholesterol. We also investigated the effects of two unusual sterols, 24-methylpollinastanol and 14 alpha,24-dimethylcholest-8-en-3 beta-ol, which were shown to accumulate in plants treated with fungicides belonging to two important classes, N-substituted morpholines and triazoles, respectively. These two sterols exhibit a behavior very similar to that of stigmasterol. The results are discussed in terms of sterol effects on the molecular packing of soybean PC bilayers.

Topics: Cholesterol; Fluorescence Polarization; Fluorescent Dyes; Glycine max; Lipid Bilayers; Liposomes; Membrane Fluidity; Phosphatidylcholines; Phytosterols; Sitosterols; Solubility; Stigmasterol

To investigate the regulation of serum levels of cholesterol precursor sterols and plant sterols, these noncholesterol sterols, fatty acids, and various parameters of cholesterol metabolism were analyzed in 63 volunteers from a randomly selected Finnish male population sample of 100 subjects, aged 50 years, who had normal dietary habits. Serum levels of cholesterol precursors, desmosterol and lathosterol (in terms of micrograms/mg cholesterol), were negatively related to both the fractional and absolute absorption of dietary cholesterol and serum high density lipoprotein (HDL) cholesterol, and positively related to overall cholesterol synthesis and serum very low density lipoprotein (VLDL) cholesterol. Serum levels of the plant sterols, campesterol and sitosterol, exhibited positive correlations with the polyunsaturated/saturated fatty acid ratio of dietary fat, the linoleic acid contents of plasma and dietary lipids, the amount of dietary plant sterols (as indicated by fecal output), fractional and absolute absorption of dietary cholesterol, and HDL cholesterol, but were inversely related to the overall cholesterol synthesis and VLDL cholesterol. Stepwise multiple regression analysis revealed that the serum level of campesterol was associated with fractional cholesterol absorption, dietary plant sterols, and biliary cholesterol secretion, and that of sitosterol with dietary plant sterols, cholesterol synthesis, fractional cholesterol absorption, and biliary cholesterol secretion. Thus, the serum non-cholesterol sterols are significant indicators of cholesterol absorption and synthesis even under basal conditions and, since gas liquid chromatographic determination of these sterols is quite simple, their measurement may be valuable for monitoring cholesterol metabolism in large-scale epidemiologic studies.

Topics: Absorption; Cholesterol; Cholesterol, Dietary; Cholesterol, HDL; Cholesterol, LDL; Desmosterol; Dietary Fats; Fatty Acids; Humans; Isomerism; Male; Middle Aged; Phytosterols; Random Allocation; Sitosterols

Formation of bile acids from sitosterol in bile-fistulated female Wistar rats was studied with use of 4-14C-labeled sitosterol and sitosterol labeled with 3H in specific positions. The major part (about 75%) of the 14C radioactivity recovered as bile acids in bile after intravenous administration of [4-14C]sitosterol was found to be considerably more polar than cholic acid, and only trace amounts of radioactivity had chromatographic properties similar to those of cholic acid and chenodeoxycholic acid. It was shown that polar metabolites were formed by intermediate oxidation of the 3 beta-hydroxyl group (loss of 3H from 3 alpha-3H-labeled sitosterol) and that the most polar fraction did not contain a hydroxyl group at C7 (retention of 3H in 7 alpha,7 beta-3H2-labeled sitosterol). Furthermore, the polar metabolites had lost at least the terminal 6 or 7 carbon atoms of the side chain (loss of 3H from 22,23-3H2- and 24,28-3H2-labeled sitosterol). Experiments with 3H-labeled 7 alpha-hydroxysitosterol and 4-14C-labeled 26-hydroxysitosterol showed that none of these compounds was an efficient precursor to the polar metabolites. By analysis of purified most polar products of [4-14C] sitosterol by radio-gas chromatography and the same products of 7 alpha,7 beta-[2H2]sitosterol by combined gas chromatography-mass spectrometry, two major metabolites could be identified as C21 bile acids. One metabolite had three hydroxyl groups (3 alpha, 15, and unknown), and one had two hydroxyl groups (3 alpha, 15) and one keto group. Considerably less C21 bile acids were formed from [4-14C]sitosterol in male than in female Wistar rats. The C21 bile acids formed in male rats did not contain a 15-hydroxyl group. Conversion of a [4-14C]sitosterol into C21 bile acids did also occur in adrenalectomized and ovariectomized rats, indicating that endocrine tissues are not involved. Experiments with isolated perfused liver gave direct evidence that the overall conversion of sitosterol into C21 bile acids occurs in this organ. Intravenously injected 7 alpha,7 beta-3H-labeled campesterol gave a product pattern identical to that of 4-14C-labeled sitosterol. Possible mechanisms for hepatic conversion of sitosterol and campesterol into C21 bile acids are discussed.

Topics: 3-alpha-Hydroxysteroid Dehydrogenase (B-Specific); 3-Hydroxysteroid Dehydrogenases; Animals; Bile; Bile Acids and Salts; Carbon Radioisotopes; Cholesterol; Chromatography, Gas; Chromatography, High Pressure Liquid; Female; Hydroxylation; Liver; Male; Mass Spectrometry; NAD; Oxidation-Reduction; Phytosterols; Rats; Rats, Inbred Strains; Sitosterols; Tritium

Hepatic and serum phytosterol concentrations were compared in the rat under basal conditions and during activated cholesterol and bile acid production due to squalene and cholestyramine feeding. Both treatments consistently decreased hepatic and serum levels of sitosterol and campesterol and, unlike esterified cholesterol, esterified plant sterols were not increased in liver during squalene feeding. Serum levels of phytosterols were decreased quite proportionately to those in the liver. The hepatic levels of sitosterol and campesterol closely correlated with each other, but not with cholesterol levels. The percentage esterification of both phytosterols was lower than that of cholesterol. The results indicate that activation of hepatic sterol production leads to depletion of hepatic plant sterols. It is suggested that poor esterification of plant sterols may contribute to this decrease.

Topics: Animals; Cholesterol; Cholestyramine Resin; Esterification; Liver; Male; Phytosterols; Rats; Rats, Inbred Strains; Sitosterols; Squalene

The effect of phytosterol-rich diets (3% beta-sitosterol + 2% campesterol) on rat liver microsomal fatty acid desaturases, membrane dynamics and lipid composition was investigated. After a 21 day period, phytosterol was incorporated into microsomes and the membrane fluidity decreased. There were no changes in either the phospholipid composition or in the total sterol content. However, the phytosterol/cholesterol ratio increased. In the animals fed phytosterols, the delta 5-, delta 6- and delta 9-fatty acid desaturases were significantly more active than in control animals. The changes in the lipid fatty acid composition were consistent with those of the desaturase activities. Hence, it is suggested that: (1) dietary phytosterol modulates desaturase activities; (2) phytosterols make the membrane more rigid but do not induce changes in the relative phospholipid composition; (3) delta 9-, delta 5- and delta 6-desaturase activities increase when the membrane becomes more rigid without changes in the phospholipid composition.

Topics: Animals; Cholesterol; Diet; Fatty Acid Desaturases; Fluorescence; Male; Microsomes, Liver; Phytosterols; Rats; Rats, Inbred Strains; Sitosterols

The role of cholesterol and bile acid malabsorption in the regulation of plasma plant sterol levels was studied in 30 patients with an ileal resection (seven without any malabsorption, eight with bile acid malabsorption alone and 15 with bile acid, fat and cholesterol malabsorption) and nine with jejunoileal bypass (modest bile acid, and severe cholesterol and fat malabsorption). In contrast to cholesterol, plant sterols are not synthesized by the body, and so the plasma levels are regulated by their intestinal absorption and biliary secretion. In fact, the plant sterol, especially campesterol, levels were low in patients with cholesterol and fat malabsorption. Cholesterol absorption efficiency was a significant determinant of the plant sterol levels, suggesting that it reflects overall sterol absorption efficiency and that the plasma plant sterol levels, in turn, reflect cholesterol absorption. Bile acid malabsorption, though it appeared to promote biliary plant sterol secretion, had little direct effect on the plasma plant sterol contents. The results indicate that plasma campesterol levels can be used to evaluate cholesterol absorption efficiency in general and may reveal clinically significant steatorrhoea in patients with gut exclusion.

Topics: Adult; Aged; Cholesterol; Humans; Ileum; Intestinal Absorption; Jejunoileal Bypass; Lipids; Malabsorption Syndromes; Middle Aged; Phytosterols; Sitosterols

To understand better the mechanism of higher absorption of cholesterol and campesterol in high-responding than in low-responding rhesus monkeys, we measured the concentrations of the two sterols in the micellar fraction isolated from small intestinal content, and also determined their rates of esterification by cholesterol esterase prepared from the small intestinal mucosa. The results show that the concentrations of both cholesterol and campesterol in the micellar fraction were significantly higher in the high- than in low- and intermediate-responding rhesus monkeys. Also the rates of esterification of both sterols are higher in the proximal segment of the small intestine in high-responders than the other two groups. We conclude that the two necessary steps in the process of sterol absorption, namely, the amounts of sterols solubilized in micelles and their esterification within mucosal cells which are higher in high- than in low-responders are responsible for the higher absorption of the sterols in the high-responding rhesus monkeys.

Topics: Animals; Cholesterol; Cholesterol, Dietary; Fatty Acids; Intestinal Absorption; Intestine, Small; Macaca; Macaca mulatta; Male; Micelles; Phytosterols; Sitosterols; Sterol Esterase

Paramecium tetraurelia is a naturally occurring sterol auxotroph with an absolute nutritional requirement for one of a small group of structurally related phytosterols. We report here a quantitative study demonstrating that a low, otherwise sub-supportive, concentration (approximately 0.020-0.050 micrograms ml-1) of an essential phytosterol (stigmasterol) is adequate for growth of this ciliate, provided that a second, relatively non-specific sterol is available at a higher concentration (1.0 micrograms ml-1) to allow for membrane biosynthesis. This phenomenon, referred to as sterol synergism, has been observed in a broad taxonomic range of organisms, with the conclusion that small amounts of specific sterols are required to perform some previously unknown, vital metabolic or regulatory function. Paramecium promises to be an excellent model organism for the elucidation of essential sterol function.

Topics: Animals; Cholesterol; Culture Media; Drug Synergism; Ergosterol; Paramecium; Phytosterols; Sterols; Stigmasterol; Triterpenes

Plasma lathosterol levels reflect cholesterol synthesis, especially that induced by bile acid malabsorption, whereas plasma plant sterol contents change in parallel with cholesterol and fat absorption. The significance of lathosterols and plant sterols (campesterol and sitosterol) was therefore studied in detection of ileal dysfunction in 29 patients with ileal resection (7 with no malabsorption, 8 with only bile acid malabsorption, and 15 with bile acid, fat, and cholesterol malabsorption) and in 8 jejunoileal bypass patients with fat, bile acid, and cholesterol malabsorption. Ileal dysfunction-induced faecal loss of bile acids was proportionate to cholesterol synthesis, which, in turn, was proportionate to the plasma levels of lathosterols, so that the lathosterols contents were also closely correlated (r = 0.880) to faecal bile acids. The lower the cholesterol absorption, the lower was the plasma campesterol (less consistently, beta-sitosterol) level and the higher the faecal fat. Thus, elevated plasma lathosterol content is highly suggestive of bile acid malabsorption in a patient with suspected ileal dysfunction. High plasma content of lathosterols combined with a low campesterol level points to associated fat malabsorption, indicating that the lathosterol to campesterol ratio in plasma is frequently increased in patients with ileal dysfunction associated with steatorrhoea.

Topics: Bile Acids and Salts; Cholesterol; Feces; Humans; Ileum; Intestinal Absorption; Jejunoileal Bypass; Phytosterols; Sitosterols

The sterol and phospholipid composition of cercariae, schistosomula, and adult Schistosoma mansoni was analyzed by gas-liquid chromatography and high-performance liquid chromatography (HPLC). Cercariae and schistosomula contained cholesterol, desmosterol, campesterol, stigmasterol, and beta-sitosterol while adults contained only cholesterol. In all stages cholesterol comprised greater than 50% of the total sterols, and in cercariae and schistosomula desmosterol comprised 38 and 21% of the total sterols, respectively. The other three sterols, campesterol, stigmasterol, and beta-sitosterol, made up approximately 10% of the total. The same five sterols found in cercariae and schistosomula were present in the hepatopancreas of uninfected snails but with a much higher desmosterol concentration in the parasite, 38%, than in the snail, 2%. As in cercariae and schistosomula the three minor sterols comprised approximately 10%. Thus, the sterol composition of cercariae and schistosomula was similar but not identical to that of the snail host. Phosphatidylcholine was the major phospholipid of all three stages (50%) as determined by two HPLC procedures. The remaining phospholipids consisted of phosphatidylethanolamine, phosphatidylserine, and phosphatidylinositol. In addition, in adults there were small quantities of sphingomyelin and lysophosphatidylcholine. The percentage of each phospholipid was similar among stages with the exception of a slight increase in phosphatidylserine in adults compared to cercariae and schistosomula. These results show that a characteristic lipid composition is found in cercariae, schistosomula, and adults.

Topics: Animals; Cholesterol; Chromatography, Gas; Chromatography, High Pressure Liquid; Desmosterol; Phosphatidylcholines; Phosphatidylethanolamines; Phosphatidylinositols; Phosphatidylserines; Phospholipids; Phytosterols; Schistosoma mansoni; Sitosterols; Sterols; Stigmasterol

The concentrations of the plant sterols, campesterol and beta-sitosterol in serum, normally correlate with the efficiency of cholesterol absorption, whereas the concentration of lathosterol, a cholesterol precursor sterol, closely parallels changes in cholesterol synthesis. In this study we explored whether the plant sterol concentrations in serum in coeliac disease are determined by cholesterol absorption and whether they alone or with the serum lathosterol concentration, could be used for screening the activity of coeliac disease. In six patients the plant sterol concentrations in serum were significantly lower than in 17 control subjects, the reduction being more marked for campesterol than for beta-sitosterol: the serum lathosterol concentration was significantly higher than in the control subjects. The opposite changes in serum plant sterols and lathosterol were recorded in patients on a gluten-free diet. The plant sterol concentrations in serum (nmol/mg of cholesterol) were positively correlated with each other, and with the percentage absorption of cholesterol and with xylose absorption; they were negatively correlated with faecal fat, but not with faecal plant sterols. Thus, the low plant sterol concentrations in serum in coeliac disease were attributable to their impaired absorption, which in turn was closely associated with the absorption of cholesterol. The serum campesterol concentration clearly distinguished the untreated patients from the controls, whereas the use of serum beta-sitosterol, and the serum ratios of lathosterol/plant sterol resulted in some overlapping with the controls. It is suggested that the plant sterols in serum might be worth of determining when screening patients for coeliac disease and especially when testing their adherence to the gluten-free diet.

Topics: Celiac Disease; Cholesterol; Cholesterol, Dietary; Glutens; Humans; Phytosterols; Sitosterols

Tobacco sterols (cholesterol, beta-sitosterol, campesterol, and stigmasterol) are present in tobacco smoke and appear in plasma of mammals exposed to cigarette smoke. Because tobacco sterols may be important in the pathogenesis of smoking-induced lung and vascular diseases, we studied the pattern of deposition of cigarette sterols in the lungs and appearance of cigarette sterols in plasma and body organs of rats. After exposure to twenty 5 ml "puffs" of smoke from tobacco labeled with [4-14C]cholesterol or beta-[4-14C]sitosterol, rats were killed just after exposure (day 0) and on days 2, 5, 8, 11, 15, and 30, and the lungs and selected body organs analyzed for activity. We found that cigarette sterols are associated with particulates in cigarette smoke, deposited mostly in distal airspaces and parenchyma of the lungs, and appear in plasma and several body organs for more than 30 days after this single exposure to cigarette smoke. Bronchoalveolar lavage fluid contained relatively small amounts of radiolabel for only the first few days, suggesting that most of the sterols were rapidly incorporated in lung parenchyma. Because disorders of sterol metabolism have been implicated in a variety of diseases including atherosclerosis and cancer, the significance of tobacco sterols to human smoking-induced diseases deserves further study.

Topics: Animals; Bronchoalveolar Lavage Fluid; Cholesterol; Esophagus; Gastric Mucosa; Kidney; Liver; Lung; Male; Nicotiana; Phytosterols; Plants, Toxic; Rats; Rats, Inbred Strains; Sitosterols; Smoke; Spleen; Sterols; Stigmasterol; Tissue Distribution

The interaction of the polyene antibiotic, filipin, with individual or mixed plant sterols (stigmasterol, sitosterol, campesterol and 24-methylpollinastanol) incorporated into large unilamellar vesicles (LUV) of soybean phosphatidylcholine (PC) as well as the filipin interaction with purified membrane fractions from maize roots containing these sterols was investigated by ultraviolet (UV) absorption and and circular dichroism (CD) spectroscopy. With both types of membrane preparation, dramatic changes in the UV absorption and CD spectra of the antibiotic were evidenced. When LUV containing stigmasterol, sitosterol and/or campesterol were incubated with low filipin concentrations (i.e., for filipin/sterol molar ratios (rst) lower than 1), CD signal characteristic of the formation of filipin-sterol complexes were observed. At higher rst values, the filipin-sterol interaction was shown to be in competition with a filipin-phospholipid interaction. With 24-methylpollinastanol-containing LUV, the filipin-phospholipid interaction was detected even at rst values lower than 1, which suggests a lower affinity of filipin for this sterol and emphasizes the structural differences between delta 5-sterols and 9 beta,19-cyclopropylsterols. With sterol-free soybean PC LUV, a filipin-phospholipid interaction could also be evidenced. With maize root cell membranes containing either delta 5-sterols or 9 beta,19-cyclopropylsterols, CD spectra similar to those obtained in the presence of LUV having these sterols as components were observed. Thus, the protein component of the membranes does not appear to be an important feature.

Topics: Cell Membrane; Cholestanols; Cholesterol; Circular Dichroism; Filipin; Liposomes; Phytosterols; Plants; Polyenes; Sitosterols; Spectrophotometry, Ultraviolet; Stigmasterol; Zea mays

Factors regulating the metabolism of plant sterols (sitosterol and campesterol) and their serum levels were studied in sixteen patients with heterozygous familial hypercholesterolemia. Eight patients had undergone an ileal bypass operation, resulting in slight fat and severe bile acid malabsorption and in lowered serum cholesterol concentration, but normal fractional cholesterol absorption. Serum plant sterol concentrations (mg/dl) were similar in the two groups, but expressed per milligram of cholesterol were higher in the operated patients. Fecal excretion (equal with intake) and biliary secretion (reflecting absorption) of the plant sterols were similar in the two groups and were significantly correlated with the serum plant sterol content, which also correlated positively with the fractional cholesterol absorption in the control but not in the operated group. The estimated fractional absorption of the plant sterols was similar in the two groups, but that of sitosterol (3.5%) was lower than that of campesterol (9.1%). Our study shows that serum plant sterols are associated with fractional cholesterol absorption even in patients with familial hypercholesterolemia. However, after ileal exclusion dietary intake of the plant sterols is the main regulator of their serum levels.

Topics: Bile Acids and Salts; Cholesterol; Female; Humans; Hyperlipoproteinemia Type II; Ileum; Intestinal Absorption; Jejunoileal Bypass; Male; Middle Aged; Phytosterols; Sitosterols

Ketoconazole, an antimycotic agent, given to rats for a week as 0.05% food addition had no effect on the hepatic concentrations of free and esterified cholesterol or on the activity of acyl coenzyme. A: cholesterol-acyltransferase (ACAT). However, the levels of free methylated cholesterol precursors, especially lanosterols, less markedly delta 8,24 and delta 8-dimethyl sterols and monomethyl sterols, were increased after only one day's treatment, while those of esterified methyl sterols were increased inconsistently, and those of free and esterified delta 8-lathosterol, lathosterol and desmosterol were not affected at all. Cholestyramine treatment had no significant effect on ACAT in spite of a decrease in the hepatic content of esterified cholesterol and caused a marked increase in the free cholesterol precursor levels, especially in those of lathosterols. Cholestyramine given to ketoconazole-treated rats increased the hepatic levels of delta 8 and delta 7-lathosterols but not desmosterol or methylated cholesterol precursors. Ketoconazole increased and cholestyramine markedly decreased plant sterols, sitosterol and campesterol in the liver. In serum, the contents of both lanosterols and lathosterol were increased but that of cholesterol tended to be decreased by ketoconazole (-19%). The results indicate that ketoconazole impairs demethylation processes at C-14 and to some extent at C-4 in the rat liver, resulting in lowered serum cholesterol level.

Topics: Animals; Cholesterol; Cholestyramine Resin; Ketoconazole; Kinetics; Liver; Male; Phytosterols; Rats; Rats, Inbred Strains; Sitosterols; Sterol O-Acyltransferase

High- and low-responding rhesus monkeys were fed diets containing 0.02, 0.15 and 0.75 mg/kcal cholesterol without or with 2% of a mixture of plant sterols for 6 weeks. No plant sterols were detected in the plasma of either high- or low-responding animals fed the cholesterol-containing diets but with low levels of plant sterols. After addition of 2% plant sterols to the diets, only campesterol was found in the plasma of both groups of animals. The plasma campesterol concentrations in either the high- or the low-responding groups were highest on the diet with 0.75 mg/kcal cholesterol and lowest with 0.02 mg/kcal cholesterol. Also, on all three diets, the plasma campesterol concentration was higher in the high responders than in the low responders. We conclude, based on the plasma campesterol levels, that the level of cholesterol in the diet affected the plasma level by affecting the intestinal absorption of the sterol. The higher the dietary cholesterol level, the higher the absorption of campesterol, and thus the higher the plasma level. Also, the high responders absorb higher amounts of campesterol than the low responders, a finding similar to cholesterol absorption in the high-responding rhesus monkeys.

Topics: Animals; Cholesterol; Cholesterol, Dietary; Macaca mulatta; Male; Phytosterols

Steinernema feltiae (= Neoaplectana carpocapsae), 'All' strain, was propagated in larvae of the corn earworm, Heliothis zea, which contained various sterols, in order to determine how the sterol composition of the host affects the growth, development and sterol composition of this insect-parasitic nematode. S. feltiae completed its life cycle normally in insects containing primarily cholesterol, cholestanol or 7-dehydrocholesterol, although the sterol composition of the dauer stage was affected by the sterol composition of the host. When the nematode was reared in insects containing primarily cholesterol, 55% of the sterol in the dauers was cholesterol and the other 46% was lathosterol. In contrast, cholestanol (70%) and lathostetrol (31%) were the sterols present in nematodes reared in H. zea containing primarily cholestanol. Cholestanol (43%), lathosterol (34%), campestanol and/or another 24-methylsterol (23%) and cholesterol (1%) were the sterols present in nematodes reared in H. zea containing campestanol and cholestanol as its major sterols. Lathosterol was the major sterol present in nematodes reared in H. zea containing principally 7-dehydrochlesterol. Therefore, in each case, S. feltiae metabolized some host sterol to lathosterol but the relative percentage of lathosterol in the nematode increased as it was exposed to delta 0-, delta 5- and delta 5,7-sterols, respectively. The ability of S. feltiae to utilize different host sterols may, in part, explain its success in parasitizing a wide variety of insects.

Topics: Animals; Cholestanols; Cholesterol; Dehydrocholesterols; Female; Host-Parasite Interactions; Larva; Lepidoptera; Male; Nematoda; Phytosterols; Sterols

We have measured plasma sterol composition in 14 subjects with sitosterolemia and xanthomatosis. In addition to elevated plasma phytosterol (campesterol 16 +/- 7 mg/dl and sitosterol 35 +/- 16 mg/dl) and normal to moderately high cholesterol levels (258 +/- 96 mg/dl), concentrations of 5 alpha-saturated stanols, cholestanol, 5 alpha-campestanol, and 5 alpha-sitostanol were at least 10 times greater than controls. Diets contained plentiful quantities of cholesterol and plant sterols, but only trace amounts of cholestanol (less than 2 mg/day) and no detectable 5 alpha-campestanol and 5 alpha-sitostanol, which indicated that the 5 alpha-saturated stanols were formed endogenously. Treatment with cholestyramine reduced plasma cholesterol and phytosterol levels by 45% and 5 alpha-saturated stanols by 55%. These results indicate that abnormally high plasma concentrations of cholestanol, 5 alpha-campestanol, and 5 alpha-sitostanol are found in subjects with sitosterolemia and xanthomatosis, and that treatment with cholestyramine effectively reduced elevated plasma sterol levels.

Topics: Adolescent; Adult; Child; Cholestanols; Cholesterol; Cholestyramine Resin; Female; Humans; Male; Middle Aged; Phytosterols; Sitosterols; Xanthomatosis

Topics: Cholesterol; Chromatography, Gas; Phytosterols; Plants; Sitosterols; Stigmasterol

The utilization of methanol by Candida lipolytica was studied with respect to the biomass, protein, lipid and other metabolites contents. Supplementation of the methanol medium with certain redox agents such as 2,6-dichlorophenol indophenol, reduced glutathione and methyl red, showed a stimulation of both growth and protein production of C. lipolytica. At certain growth conditions the cellular yield of C. lipolytica was 0.3 g of cells/g of methanol and the protein of the biomass was 41.0%. The amino acid composition of the protein especially of the essential ones was comparable to FAO standards. Thin-layer chromatography of the lipids indicated a dominance of total glycerides. Analyses of the acylated unsaponified fraction by gas liquid chromatography showed that campesterol was the major component.

Topics: 2,6-Dichloroindophenol; Amino Acids; Azo Compounds; Biotin; Candida; Cholesterol; Culture Media; Dietary Proteins; Fungal Proteins; Glutathione; Glycerides; Guanine; Lipids; Methanol; Phosphorus; Phytosterols

The effects of feeding diets with high or low amounts of cholesterol and with low or high levels of mixed plant sterols (sitosterol: campesterol: stigmasterol, 60:35:5) on the daily fecal excretion of acidic steroids were studied in rhesus monkeys. During periods of low dietary plant sterol, total fecal acidic steroid excretion was 43% lower (P less than 0.01) during low dietary cholesterol than during high dietary cholesterol. During periods of high dietary plant sterols the fecal acidic steroid excretion was 113% higher (P less than 0.01) with low dietary cholesterol than with high dietary cholesterol. Addition of mixed plant sterols to the low-cholesterol diet produced nearly a 2-fold increase (P less than 0.005) whereas, such an addition to the high cholesterol diet produced a significant decrease by about 53% (P less than 0.025) in the total fecal acidic steroid excretion. The results suggest that the effect of cholesterol feeding on fecal acidic steroid excretion depends on the level of plant sterols in the diet. This interaction of the effects of cholesterol and plant sterols on the fecal acidic steroid excretion is probably related to the inhibitory effect of plant sterols on cholesterol absorption.

Topics: Animals; Bile Acids and Salts; Cholesterol; Cholesterol, Dietary; Feces; Intestinal Absorption; Macaca mulatta; Male; Phytosterols

The sterol fraction of Stevia rebaudiana Bertoni contains, essentially, the following sterols: stigmasterol (45,8%), beta-sitosterol (39,4%) and campesterol (13,1%). The individual components were separated, after acetylation, by HPLC with absolute methanol as eluant. The identification of the compounds has been carried out through NMR and MS, while the corresponding percentages have been desumed from the GLC data.

Topics: Cholesterol; Phytosterols; Plants, Medicinal; Sitosterols; Stigmasterol

The sterol fraction of Equisetum arvense L. contains, essentially, the following sterols: beta-sitosterol (60.0%), campesterol (32.9%), isofucosterol (5.9%) and cholesterol (trace amounts). The identification of the compounds has been carried out through NMR and MS, while the corresponding percentage have been desumed from the GLC and HPLC data.

Topics: Cholesterol; Chromatography, Gas; Chromatography, High Pressure Liquid; Magnetic Resonance Spectroscopy; Phytosterols; Plants, Medicinal; Sitosterols; Stigmasterol

Topics: Cholesterol; Phytosterols; Plants, Medicinal; Sitosterols; Stigmasterol

The honey bee, Apis mellifera, does not convert C28 and C29 phytosterols to cholesterol as found in most previous studies of phytophagous or omnivorous insects, but instead the workers and queens selectively transfer 24-methylenecholesterol, sitosterol and isofucosterol from their endogenous sterol pools to the brood larvae regardless of the sterol in the worker diet. Administering radiolabeled sterols by feeding and injection has made it possible to trace this selective transfer through a second generation of the honey bee. In further comparative sterol metabolism studies, the yellow fever mosquito, Aedes aegypti, was shown to be capable of dealkylating and converting a radiolabeled C29 dietary sterol ([14C]sitosterol) to cholesterol. Metabolic studies with several radiolabeled dietary sterols and an inhibitor of steroid metabolism in the yellow fever mosquito further verified this capability.

Topics: Aedes; Animals; Bees; Cholesterol; Desmosterol; Diet; Larva; Phytosterols; Sitosterols; Sterols

Topics: Animals; Cholesterol; Cholesterol Esters; Female; Intestinal Absorption; Intestine, Small; Male; Phytosterols; Rats; Rats, Inbred Strains; Sitosterols; Stigmasterol

Cultures of Tetrahymena pyriformis were incubated with various sterols and the extent of dehydrogenation at C-7 and C-22 was determined. The sterols incubated were desmosterol, 22-dehydrodesmosterol, 24-methyldesmosterol, 24 alpha-methylcholesterol (campesterol), 24-methylene-cholesterol, isohalosterol (26,27-bisnorcampesterol, also known as 24,24-dimethylchol-5-en-e beta-ol, a naturally occurring C26-sterol), and 20-isohalosterol. 20-Isohalosterol was not metabolized, while products with delta 7- and delta 22-bonds were formed from isohalosterol and all of the other sterols studied. This confirms an earlier conclusion, based on results with 20-isocholesterol and cholesterol, that inversion of the configuration from 20(R) to 20(S) completely prevents metabolism both in the nucleus and the side chain. On the other hand, changes in the electronics or stereochemistry at C-24 had a direct affect only on metabolism in the side chain. The presence of a methyl group at C-24 reduced the yield of metabolites with a delta 22-bond relative to those with a delta 7-bond producing an accumulation of 7-dehydro metabolite. A double bond at position-24 counteracted this steric effect, presumably by enhancing the rate of dehydrogenation, and a delta 24(28)-bond was more effect than was a delta 24(25)-bond.

Topics: Animals; Cholesterol; Desmosterol; Molecular Conformation; Phytosterols; Sterols; Tetrahymena pyriformis

An adult Chinese man presented with tendinous and tuberous xanthomatosis and severe atheromatous changes in the coronary arteries. In addition, he had chronic hemolytic anemia, with spherostomatocytic erythrocytes. Cerebrotendinous xanthomatosis was diagnosed on the basis of increased cholestanol levels in his plasma, red cells and xanthoma, changes in bile acid composition due to the defective synthesis of chenodeoxycholic acid. Coexisting beta-sitosterolemia was confirmed by the finding of large amounts of the plant sterols such as beta-sitosterol and campesterol. This is the first report of these two rare lipid storage disorders in the same patient.

Topics: Adult; Anemia, Hemolytic; Chenodeoxycholic Acid; Cholestanols; Cholesterol; Coronary Disease; Humans; Lipidoses; Phytosterols; Sitosterols; Spherocytes; Xanthomatosis

Topics: Bile; Bile Acids and Salts; Cholesterol; Chromatography, Gas; Fatty Acids; Humans; Phospholipids; Phytosterols

The sterol mixture of the southern Japan's soft coral, Sarcophyton glaucum, was found to contain 11 sterols including a novel sterol, 23,24 xi-dimethylcholesta-5,22-dien-3 beta-ol and a new diunsaturated C29 sterol. 22,23-Dihydrobrassicasterol and gorgosterol were the major components in free- and esterified sterols respectively. Brassicasterol was found in S. glaucum, in contrast to the ubiquity of 24-epibrassicasterol in the marine invertebrates in the northern districts. The new sterol (sarcosterol) was isolated; its structure as 23 xi, 24 xi-dimethylcholesta-5, 17(20)-trans-dien-3 beta-ol was based on spectra evidence and comparison with cholesta-5, 17(20)-trans-dien-3 beta-ol.

Topics: Animals; Cholestadienols; Cholesterol; Cnidaria; Dehydrocholesterols; Phytosterols; Sterols

Topics: Amphibian Venoms; Animals; Bufonidae; Cholestadienols; Cholesterol; Chromatography, Gas; Mass Spectrometry; Phytosterols; Sitosterols; Sterols; Stigmasterol; Vietnam

Rabbits were fed a low cholesterol diet containing 2% plant sterols for 10 weeks to determine the absorbability of these sterols and their deposition in the tissues. We found campesterol and beta-sitosterol in the blood and tissues. The plasma campesterol levels were 4.34--13.3 mg/100 ml, whereas, beta-sitosterol levels were 0.41--1 mg/100 ml. Stigmasterol was not detected. The total plasma plant sterol concentration was about 10% of the total plasma sterol. The mean terminal plasma cholesterol concentration averaged 60% higher (55 vs. 88 mg/100 ml, P less than 0.001) than the mean initial value. Campesterol was the preponderant sterol in all tissues studied, including the aorta. Sitosterol was found in small amounts in the tissues of the abdominal organs. Stigmasterol was not detected in any tissue studied. Esterified campesterol and sitosterol were detected in trace amounts in most tissues. Campesterol and sitosterol, particularly the former, accumulated in the tissues including the aorta.

Topics: Animals; Cholesterol; Cholesterol, Dietary; Female; Humans; Phytosterols; Rabbits; Sitosterols; Stigmasterol; Tissue Distribution

A gas-liquid chromatographic (GLC) method, using the butyryl esters of sterols, has been developed for the measurement of cholesterol, stigmasterol, sitosterol, and campesterol in foods. An immobile phase of 1% SE-30 coated on 100-120 mesh Gas-Chrom Q packed in a 6 inch X 4 mm id glass column operated at 255 degrees C was the most satisfactory of 7 column packings evaluated. Extraction with chloroform-methanol gave 98.7% recovery with a coefficient of variation of 1.8% for cholesterol added to a variety of foods. When cholesteryl palmitate was added to vegetable oil and the butyryl derivative was prepared, followed by GLC analysis, the recovery was 99.3% with a coefficient of variation of 0.9%. Amounts as low as 1 mg/100 g food can be detected with a precision of 2.5%. The results of the analysis of a variety of foods for cholesterol, campesterol, sitosterol, and stigmasterol are given.

Topics: Cholesterol; Cholesterol Esters; Chromatography, Gas; Chromatography, Liquid; Food Analysis; Methods; Phytosterols; Sitosterols; Stigmasterol

The extent of the side chain hydroxylation of cholesterol, campesterol (24 alpha-methylcholesterol), and beta-sitosterol (24 alpha-ethylcholesterol) in rat liver mitochondria has been compared. Two beta-sitosterol metabolites, tentatively identified by liquid chromatography, thin-layer chromatography, gas-liquid chromatography, combined with radioactivity detection, and gas-liquid chromatography-mass spectrometry as the 26- and 29-hydroxy derivatives, were formed in the proportion 1:1. The sum of 26-hydroxy- and 29-hydroxy-beta-sitosterol obtained amounted only to about one-fourth of the yield of 26-hydroxycholesterol. Campersterol appeared to give rise only to 26-hydroxycampesterol (tentatively identified), which was formed in similar yields as 26-hydroxycholesterol (0.2-0.4%). The formation of 29-hydroxy-beta-sitosterol but not of 28-hydroxycampesterol indicates that the omega-hydroxylation of the steroid side chain is dependent on the length of the side chain. Cholesterol gave rise to identifiable amounts of a 25-hydroxy derivative but the formation of 25-hydroxy derivatives of beta-sitosterol and campesterol could not be established with certainty. 24-hydroxycholesterol was also found to be formed in the mitochondrial system. The ratio between the yields of 26- and 25-hydroxychoelsterol ranged between 2 and 3, and that between 26- and 24-hydroxycholesterol was about 10.

Topics: Animals; Cholesterol; Chromatography, Liquid; Chromatography, Thin Layer; Gas Chromatography-Mass Spectrometry; Hydroxycholesterols; Hydroxylation; Hydroxysteroids; Ketosteroids; Male; Mitochondria, Liver; Oxidation-Reduction; Phytosterols; Rats; Sitosterols; Structure-Activity Relationship

Topics: Chemical Phenomena; Chemistry; Cholestadienols; Cholesterol; Ergocalciferols; Ergosterol; Phytosterols; Research; Sterols

Topics: Chemistry, Pharmaceutical; Cholesterol; Chromatography; Phytosterols; Research; Sitosterols; Sterols; Stigmasterol

Topics: Cholesterol; Glucosides; Glycosides; Humans; Nicotiana; Phytosterols; Sitosterols; Smoke; Smoking; Sterols; Stigmasterol