stigmastanol and gamma-sitosterol

Sitosterolemia is a rare, autosomal recessive inherited sterol storage disease associated with high tissue and serum plant sterol concentrations, caused by mutations in the adenosine triphosphate-bind-ing cassette (ABC) transporter ABCG5 or ABCG8 genes. Markedly increased serum concentration of plant sterols. such as sitosterol and campesterol, cause premature atherosclerosis and massive xanthomas. Hitherto known treatments for sitosterolemia, including a low-sterol diet, bile-salt binding resins, ileal bypass surgery and low density lipoprotein (LDL) apheresis have not yielded sufficient reduction of serum plant sterol levels and many patients show a sustained elevation of plant sterol levels, subsequently developing premature atherosclerotic cardiovascular diseases. Ezetimibe, an inhibitor of intestinal cholesterol absorption through its binding to Niemann-Pick C1-like 1 (NPC1L1), has been widely used for decreasing serum LDL-cholesterol levels in patients with hypercholesterolemia. Ezetimibe also reduces the gastrointestinal absorption of plant sterols, thereby also lowering the serum concentrations of plant sterols. This pharmacological property of ezetimibe shows its potential as a novel effective therapy for sitosterolemia. In the current review, we discuss the current therapy for patients with sitosterolemia and present two Japanese adolescent patients with this disease, one of whom underwent percutaneous coronary intervention for accelerated coronary atherosclerosis. Ezetimibe administration in addition to conventional drug therapy successfully reduced serum sitosterol levels by 51.3% and 48.9%, respectively, in the two patients, demonstrating ezetimibe as a novel and potent treatment agent for sitosterolemia that could work additively with conventional drug therapy.

Topics: Adolescent; Anticholesteremic Agents; ATP Binding Cassette Transporter, Subfamily G, Member 5; ATP-Binding Cassette Transporters; Azetidines; Bile Acids and Salts; Cardiovascular Diseases; Ezetimibe; Female; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Ileum; Ion Exchange Resins; Lipid Metabolism, Inborn Errors; Lipoproteins; Male; Models, Biological; Mutation, Missense; Phytosterols; Sitosterols; Young Adult

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

Consumption of plant stanols and plant sterols decreases LDL cholesterol level and increases serum concentrations of plant stanols/sterols, but it is practically unexplored whether also their tissue concentrations increase. Thus, the aim of this study was to assess whether consuming plant stanols/sterols increases their concentrations in stenotic aortic valves and affect the valvular structure (collagen and elastin) or inflammation (macrophages and mast cells).. In a randomized, double-blind controlled intervention patients with severe aortic stenosis consumed margarine without (n = 11) or with 2 g of plant stanols (n = 12) or sterols (n = 13) until valve replacement surgery (2.6 months, on average). The effects of sitostanol and sitosterol on the expression and secretion of proinflammatory cytokines by cultured aortic valve myofibroblasts were also assessed.. Control-related LDL-cholesterol was diminished by 16% (p < 0.05) by plant stanol and by 11% (NS) by plant sterol consumption, respectively. In the resected valves, cholesterol, plant stanol and sterol levels were similar in all groups. Consumed plant stanols or sterols had no effect on valvular structure or mast cell or macrophage numbers in valves. Incubation of cultured myofibroblasts derived from stenotic valves with sitostanol or sitosterol decreased mRNA expression of the monocyte chemotactic protein-1 (p < 0.05) and interleukin-1 beta (p < 0.05).. In this study, plant stanol/sterol consumption did not affect cholesterol, plant stanol or sterol levels in stenotic aortic valves; neither did they influence the structure or the inflammatory status of the valves. However, these findings need to be confirmed in a larger-scale intervention. ClinicalTrials.govRegister #NCT00738933.

Topics: Aged; Aged, 80 and over; Aortic Valve; Chemokine CCL2; Cholesterol, LDL; Diet; Double-Blind Method; Female; Heart Valve Prosthesis Implantation; Humans; Interleukin-1beta; Male; Margarine; Middle Aged; Myofibroblasts; Phytosterols; RNA, Messenger; 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

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

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

Effects of small amounts of sitosterol, sitostanol and sitostanol esters (< 1 g/day of free sterols) dissolved in rapeseed oil (RSO) were studied on serum lipids and cholesterol metabolism in patients with primary hypercholesterolemia and different apolipoprotein E phenotypes on an RSO diet. One of the four groups was an RSO-fed control. Serum total and LDL cholesterol reductions were small in different plant sterol-fed groups, tended to be highest in the sitostanol ester group (-7%), but were significantly reduced by about 5% in the combined plant sterol groups. The reductions were -8% in the subjects with epsilon 4 allele and insignificant in those with apo E3/3 phenotype. Cholesterol precursor sterols in serum, markers of cholesterol synthesis, were increased only in the subjects with epsilon 4 allele. Cholesterol absorption was reduced by 7%, being 31% in the subjects with epsilon 4 allele, and fecal elimination of cholesterol was increased, a finding also indicating increased cholesterol synthesis. The changes in cholesterol absorption were related to those in fecal plant sterols (change in dietary intake) and serum total and LDL cholesterol (P = 0.04, 0.01 and 0.05, respectively). Thus, small amounts of dietary plant sterols (< 1 g/day), especially sitostanol esters dissolved in dietary fats, decrease serum total and LDL cholesterol by a proportional decrease in cholesterol absorption which, in turn, is associated with a compensatory increase in cholesterol synthesis. The effects are most consistent in subjects with epsilon 4 allele, but for effective hypocholesterolemic treatment dietary amount of sitostanol ester should exceed 1 g/day.

Topics: Absorption; Adult; Apolipoproteins E; Brassica; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Double-Blind Method; Fatty Acids, Monounsaturated; Female; Humans; Hypercholesterolemia; Male; Middle Aged; Phenotype; Plant Oils; Rapeseed Oil; Sitosterols; Triglycerides

The effects of two different plant sterols on intestinal cholesterol absorption were compared in normal volunteers by an intestinal perfusion study during a control period followed by high dose infusion of sitosterol or sitostanol (3.6 mumol/min), to which subjects were allocated in a randomized manner. Cholesterol absorption during the control period was similar in the two groups, averaging 0.88 +/- 0.48 mumol/min (32 +/- 11%) for group I (sitosterol) and 0.68 +/- 0.33 mumol/min (29 +/- 9%) for group II (sitostanol). The infusion of a high dose of sitosterol resulted in a significant reduction of cholesterol absorption to 0.47 mumol/min (16%). Following the same dose of sitostanol, cholesterol absorption diminished significantly to 0.15 +/- 0.11 mumol/min (5.1 +/- 2.9%). Overall cholesterol absorption declined during sitosterol infusion by almost 50%, whereas sitostanol infusion caused a reduction of cholesterol absorption by almost 85%. These findings of a more effective inhibition of cholesterol absorption by sitostanol might confirm the observation recorded by others that an increase in hydrophobicity of a plant sterol results in a higher affinity but lower capacity to mixed micells. This may cause an effective displacement of cholesterol from micellar binding and therefore diminished cholesterol absorption.

Topics: Cholesterol; Cholesterol, Dietary; Humans; Intestinal Absorption; Male; Sitosterols

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

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

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

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

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

The unsaponifiable fraction of six Tunisian monovarietal virgin olive oils from the region of Medenine was evaluated within a single chromatographic run by using HPLC-APCI-tandem MS. Separation of the compounds under study was achieved by the RP-LC method, giving a reasonable analysis time and good resolution. Detection was done by an ion trap (working alternatively in MS and MS/MS modes), the fact which made our method suitable to unequivocally identify a high number of compounds belonging to different families of the unsaponifiable fraction of oil and to carry out their reliable and sensitive quantification. A great amount of qualitative information was generated in every analysis, although we focused on the quantification of sterols, tocopherols, and triterpenic dialcohols since their standards were commercially available. The limits of detections achieved were within the range of 1.21 and 10.31 microg/kg for sitostanol and beta-sitosterol, respectively. Significant differences were observed in the composition of the studied olive cultivars. Jemri Ben Guerdane oil was the richest one in terms of all of the sterols under study. alpha-Tocopherol was the main vitamin E isomer in all samples, ranging from 70.14 to 130.72 mg/kg. Principal component analysis (PCA) and cluster analysis were applied to the whole data set in order to explore the distribution of the olive cultivars according to their oil composition.

Topics: Alcohols; Chromatography, High Pressure Liquid; Olive Oil; Phytosterols; Plant Oils; Saponins; Sitosterols; Species Specificity; Tandem Mass Spectrometry; Tocopherols; Triterpenes; Tunisia

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

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

Faecal sterols detection is a promising method for identifying sources of faecal pollution. In this study, faecal contamination in water samples from point source (sewage treatment plants, chicken farms, quail farms and horse stables) was extracted using the solid phase extraction (SPE) technique. Faecal sterols (coprostanol, cholesterol, stigmasterol, beta-sitosterol and stigmastanol) were selected as parameters to differentiate the source of faecal pollution. The results indicated that coprostanol, cholesterol and beta-sitosterol were the most significant parameters that can be used as source tracers for faecal contamination. Chemometric techniques, such as cluster analysis, principal component analysis and discriminant analysis were applied to the data set on faecal contamination in water from various pollution sources in order to validate the faecal sterols' profiles. Cluster analysis generated three clusters: coprostanol was in cluster 1, cholesterol and beta-sitosterol formed cluster 2, while cluster 3 contained stigmasterol and stigmastanol. Discriminant analysis suggested that coprostanol, cholesterol and beta-sitosterol were the most significant parameters to discriminate between the faecal pollution source. The use of chemometric techniques provides useful and promising indicators in tracing the source of faecal contamination.

Topics: Cholestanol; Cholesterol; Environmental Monitoring; Feces; Sitosterols; Solid Phase Extraction; Sterols; Stigmasterol; Water Pollutants

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

Functional foods with supplementation of plant sterols are already used by millions of people. However, at the same time it is current scientific thinking that elevation of plant sterols in the circulation causes coronary heart disease. Therefore, this study aimed to define the risk for coronary heart disease associated with moderately high plant sterol plasma levels in a cohort of elderly. In this study, we evaluated the association between plant sterols and coronary heart disease in a cohort of 1242 subjects older than 65 years, participating at the Longitudinal Aging Study Amsterdam (LASA). Concentrations of sitosterol, campesterol, brassicasterol and stigmasterol were assessed using highly sensitive and specific gas chromatography-mass spectrometry-selected ion-monitoring. Plant sterol concentrations (and their ratios to cholesterol) were slightly, however, significantly lower in patients with coronary heart disease. Moreover, high plasma concentrations of a marker plant sterol, sitosterol, were associated with a markedly reduced risk for coronary heart disease (OR 0.78, CI 0.62-0.98, p<0.05). In contrast neither plant stanols (sitostanol or campestanol) nor the cholesterol synthesis markers (lathosterol, lanosterol and desmosterol) nor their ratios to cholesterol were significantly different in the study groups. These data suggest that plant sterols could have neutral or even protective effects on development of coronary heart disease, which have to be confirmed in interventional trials.

Topics: Aged; Aged, 80 and over; Cholesterol; Coronary Disease; Cross-Sectional Studies; Female; Humans; Logistic Models; Male; Peripheral Vascular Diseases; Phytosterols; Risk Factors; Sitosterols

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

To analyze the phytosterol content in plant food commonly consumed in China, and to estimate the intake of phytosterols in Chinese people.. More than 160 types of plant food in 7 kinds were chosen as samples. The contents of beta-sitosterol, campesterol, stigmasterol, beta-sitostanol, campestanol were analyzed by GC methods and the total phytosterols were calculated. The intake of phytosteols in Chinese people was estimated using the data of "Survey on the Status of Nutrition and Health of the Chinese People" in 2002.. The contents of phytosterols in edible oils, nuts, and soybeans were higher than those in other plant food. In cereals, phytosterol contents of wheat flour were much higher than those of rice, the refinements of cereals may decrease the phytosterol contents. The phytosterol contents in vegetables and fruits were lower. The total intake of phytosterols in Chinese people was estimated to be 322.41mg/day, in which 40% may be of edible oil origin and 40% may be of cereal origin.. The results indicated that in the current dietary pattern, increase the intake of wheat, soybean, vegetable and fruit would enhance the phytosterol intake in Chinese.

Topics: China; Fabaceae; Food Analysis; Humans; Oryza; Phytosterols; Sitosterols; Triticum; Vegetables

A validated and repeatable high performance liquid chromatography (HPLC) method with online evaporative light scattering (ELSD) was developed for the analysis of two sterols, stigmasterol, beta-sitosterol and a stanol, stigmastanol, found to be common in many herbal formulations and health care supplements. The method is based on the separation of the three marker compounds on a C8 column (Phenomenex Luna, 5 microm, 150 mmx4.6 mm i.d.) using methanol:water (95:5 v/v) as the mobile phase, and a flow rate of 1 ml/min to separate all the marker compounds within 12 min. Cholesterol (50 microg/ml) was used as internal standard and methanol as the extraction solvent. The ELSD response parameters were optimised and the limits of detection (LOD) and quantification (LOQ) were calculated to be 2 and 5 microg/ml, respectively, which is more sensitive than obtained by photo diode array detection (5 and 7 microg/ml). Using ELSD, the percentage relative standard deviation (%R.S.D.) of intra-day and inter-day (3 days) precision for each marker was better than 3%, the accuracy data were within 97-103% and the recovery data were found to be within 95-107% for the five commercially available products examined. This method was used to assay commercially available products formulated as oral dosage forms purported to contain African Potato and associated sterols and stanol and proved to be suitable for the routine analysis and quality control of such products.

Topics: Administration, Oral; Chromatography, High Pressure Liquid; Dosage Forms; Light; Reference Standards; Reproducibility of Results; Scattering, Radiation; Sensitivity and Specificity; Sitosterols; Stigmasterol

In this study, we describe a simple liquid extraction (methanol/choloroform, 1:1, v/v) method for endogenous free cholesterol and administered sterols extracted from cultured Caco-2 cells. To quantify sterol contents in Caco-2 cells, a new HPLC-APCI-MS method was developed. All the sterols were baseline separated using reversed-phase column (C8, 2.1 mm x 150 mm, 3.5 microm) and isocratic conditions (90%, v/v, methanol-water mixture containing 0.2 mM ammonium acetate). The full scan mass spectra of sterols were measured by an ion trap mass spectrometer equipped with an APCI ion source. The intense fragment ions resulting from the loss of water [M+H-H2O]+ (m/z 369, 395, 397 and 399 for cholesterol, stigmasterol, sitosterol, and sitostanol, respectively) were used for determinations. The absolute extraction recovery of sterols from the spiked cell samples were 109.7+/-26.2, 105.7+/-5.1, 109.8+/-5.0 and 99.0+/-7.0% for cholesterol, stigmasterol, sitosterol, and sitostanol, respectively. Furthermore, no significant matrix effect was observed for the sterols in the cell samples. The sample assay was based on the internal standard method using stigmasterol as an internal standard. The method was linear over the concentration ranges of 0.45-9.0 microM (cholesterol) and 0.225-7.2 microM (sitosterol and sitostanol). The within- and between-day precision was less than 7% and accuracy ranged from 93.51 to 101.77%. The lowest limit of quantitation (LLOQ) was 0.225 microM for sitosterol and sitostanol, and 0.45 microM for cholesterol. The accuracy range was 95-106% and precision was lower than 9% for all LLOQ values.

Topics: Caco-2 Cells; Cholesterol; Chromatography, Liquid; Humans; Mass Spectrometry; Reproducibility of Results; Sitosterols; Sterols

Plant stanols and sterols of the 4-desmethyl family (e.g., sitostanol and sitosterol) effectively decrease LDL cholesterol concentrations, whereas 4,4-dimethylsterols (alpha-amyrin and lupeol) do not. Serum carotenoid concentrations, however, are decreased by both plant sterol families. The exact mechanisms underlying these effects are not known, although effects on micellar composition have been suggested. With a liver X receptor (LXR) coactivator peptide recruitment assay, we showed that plant sterols and stanols from the 4-desmethylsterol family activated both LXRalpha and LXRbeta, whereas 4,4-dimethyl plant sterols did not. In fully differentiated Caco-2 cells, the functionality of this effect was shown by the increased expression of ABCA1, one of the known LXR target genes expressed by Caco-2 cells in measurable amounts. The LXR-activating potential of the various plant sterols/stanols correlated positively with ABCA1 mRNA expression. Reductions in serum hydrocarbon carotenoids could be explained by the effects of the 4-desmethyl family and 4,4-dimethylsterols on micellar carotenoid incorporation. Our findings indicate that the decreased intestinal absorption of cholesterol and carotenoids by plant sterols and stanols is caused by two distinct mechanisms.

Topics: Antioxidants; ATP Binding Cassette Transporter 1; ATP-Binding Cassette Transporters; Caco-2 Cells; Carotenoids; Cholesterol; Cholesterol, LDL; DNA-Binding Proteins; Humans; Hydrocarbons; Intestinal Absorption; Intestines; Liver X Receptors; Micelles; Models, Chemical; Oleanolic Acid; Orphan Nuclear Receptors; Pentacyclic Triterpenes; Peptides; Phytosterols; Plant Extracts; Receptors, Cytoplasmic and Nuclear; Receptors, Steroid; RNA, Messenger; Sitosterols; Sterol Regulatory Element Binding Protein 2; Triterpenes

The formation of mixed water-insoluble poorly absorbable crystals between cholesterol (CH) and phytosterols (PS) or phytostanols (PSS) in the intestinal lumen has been considered for a long time as a plausible mechanism of the PS/PSS-induced reduction of serum CH concentration. In this report, we demonstrated with the use of the powder X-ray diffraction (XRD) and the differential scanning calorimetry (DSC) techniques that mixed CH:beta-sitosterol (SI) crystals can be formed by recrystallization of corresponding mixtures from melts and also from mixed CH:SI solutions in triglyceride oil. Formation of mixed CH:SI crystals takes place in a wide interval of CH:SI ratios, from approximately 10 up to approximately 75 wt.% of SI in the mixture. Formation of mixed CH:sitostanol (SS) crystals from melts and solutions in triglyceride oil was also detected, but in a more narrow interval of CH:SS ratios. However, during the lipolysis of model dietary emulsions under in vitro conditions, the formation of crystalline material was not detected due to the relatively high solubility of free sterols/stanols in products of fat hydrolysis. We found that the solubility of free CH, SI, and SS raises upon the increase in the solvent polarity, i.e. free fatty acid > diglycerideoil > triglyceride oil. Therefore, we believe that the cocrystallization mechanism of phytosterol-induced serum CH lowering has relatively low importance, unless the diet is specially designed to include relatively little amounts of dietary fats. The presented experimental evidence demonstrates that it is unlikely that the formation of poorly absorbable mixed crystals largely affects the intestinal absorption of CH and, therefore, that this is a prime mechanism by which PS and PSS effect CH absorption.

Topics: Absorption; Calorimetry, Differential Scanning; Cholesterol; Crystallization; Lipase; Phytosterols; Sitosterols; Solubility; Triglycerides; X-Ray Diffraction

The effect of a plant sterol, beta-sitosterol (SI), and a plant stanol, sitostanol (SS), on the solubilization of cholesterol (CH) by model dietary mixed micelles was examined under in vitro conditions with the use of gas chromatography, isothermal titration calorimetry, NMR spectroscopy and cryogenic transmission electron microscopy techniques. Free SI and SS were shown to reduce the concentration of CH in dietary mixed micelles via a dynamic competition mechanism. CH, SI and SS affect the microstructure of lipid vesicles and influence the process of amphiphilic self-assembly of nutrients in the gut with the formation of dietary mixed micelles in a similar manner. Therefore, substitution of CH by phytosterols and phytostanols in the diet does not lead to the notable changes in the mechanism of dietary mixed micelle formation and does not affect the process of the intestinal transport of nutrients and drugs via the micellar diffusion mechanism. Our experimental findings demonstrate that the introduction of plant sterols and plant stanols into the diet is clearly beneficial for the reduction of the intestinal uptake of cholesterol. Due to the limited capacity of dietary mixed micelles to embody hydrophobic sterol/stanol molecules, the micellar concentration of cholesterol is reduced and hence, its transport towards the intestinal brush border membrane decreases.

Topics: Bile Acids and Salts; Calorimetry; Cholesterol; Cholesterol, Dietary; Chromatography, Gas; Cryoelectron Microscopy; Hypolipidemic Agents; Micelles; Nuclear Magnetic Resonance, Biomolecular; Oleic Acid; Phosphatidylcholines; Sitosterols; Solubility; Thermodynamics

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

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

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

Sterols (sitosterol, cholesterol, stigmasterol, ergosterol, and 7-dehydrocholesterol) and sitostanol have been converted in high to near-quantitative yields to the corresponding long-chain acyl esters via esterification with fatty acids or transesterification with methyl esters of fatty acids or triacylglycerols using lipase from Candida rugosa as biocatalyst in vacuo (20-40 mbar) at 40 degrees C. Neither organic solvent nor water is added in these reactions. Under similar conditions, cholesterol has been converted to cholesteryl butyrate and steroids (5alpha-pregnan-3beta-ol-20-one or 5-pregnen-3beta-ol-20-one) have been converted to their propionic acid esters, both in moderate to high yields, via transesterification with tributyrin and tripropionin, respectively. Reaction parameters studied in esterification include the temperature and the molar ratio of the substrates as well as the amount and reuse properties of the C. rugosa lipase. Lipases from porcine pancreas, Rhizopus arrhizus, and Chromobacterium viscosum are quite ineffective as biocatalysts for the esterification of cholesterol with oleic acid under the above conditions.

Topics: Candida; Catalysis; Cholesterol; Dehydrocholesterols; Ergosterol; Esterification; Fatty Acids; Kinetics; Lipase; Sitosterols; Sterols; Stigmasterol; Substrate Specificity; Triglycerides; Vacuum

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

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

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

Topics: Administration, Oral; Anticholesteremic Agents; Cross-Over Studies; Double-Blind Method; Drug Administration Schedule; Female; Humans; Male; Margarine; Phytosterols; Randomized Controlled Trials as Topic; Sitosterols

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

For over a decade investigators have quantified cholesterol absorption by comparison of dietary intake and fecal excretion of isotopic cholesterol with that of beta-sitosterol as a "nonabsorbable" marker. However, beta-sitosterol might not be ideal due to its potential for absorption. We therefore carried out two studies to evaluate a new marker with less potential for absorption, [3H]beta-sitostanol. In the first study (Study I, n = 22), we compared absorption of [3H]beta-sitostanol and [14C]beta-sitosterol in a simultaneous dual-label continuous feeding ("phytosterol absorption") experiment. We observed a consistently higher ratio of [3H]beta-sitostanol/[14C]beta-sitosterol in the stool relative to diet on the first day of fecal collection (6.1% +/- 3.2% loss of [3H]beta-sitosterol, range 3-12%), but thereafter, the ratio in stool was similar to that in diet. In Study II (n = 23), we compared cholesterol absorption directly using [3H]beta-sitosterol and [14C]cholesterol, and, separately, [3H]beta-sitostanol and [14C]cholesterol. We found that mean absorption between the two methods was similar (45% +/- 11% versus 44% +/- 10%, respectively, P difference = 0.40), and the two methods correlated well with one another (r = 0.83) when samples from all available days were used. Variability between the two methods was greater in individuals who absorbed more than 40% of cholesterol. Cholesterol loss on day 2 estimated from use of beta-sitostanol as a nonabsorbable marker was predictive of absorption using ratios from days 4-6 (r = 0.80). These results suggest that, for the majority of subjects, beta-sitosterol is a valid nonabsorbable marker for cholesterol absorption.

Topics: Adult; Aged; Biomarkers; Cholesterol; Evaluation Studies as Topic; Female; Humans; Intestinal Absorption; Male; Middle Aged; Reference Values; 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

The objective of this study was to determine the effects of diets containing non-heated and thermally oxidized olive oils on fecal endogenous lipids. Male Wistar rats were fed fat-free diets and diets supplemented with 12% non-heated, heated, and a 1:1 mixture of non-heated/heated olive oils. After a 15-day experimental period two groups of fecal lipids from major endogenous sources were quantitated: neutral sterols and fatty acids associated with intestinal microflora action. Fecal endogenous sterols, particularly cholesterol, were significantly higher when diets contained oil, and excretion increased as the dietary oil alteration increased. Similar results were obtained for endogenous fatty acids. Increments of fecal sterols, dependent on oil alteration, could be explained by impairments in triglyceride hydrolysis and subsequent effect on cholesterol micellar solubilization. Moreover, high concentrations of poorly digestible lipids may have led to intestinal microbial modifications.

Topics: Animals; Cholestanol; Cholesterol; Dietary Fats, Unsaturated; Fatty Acids; Feces; Hot Temperature; Lipid Metabolism; Male; Olive Oil; Plant Oils; Rats; Rats, Wistar; Sitosterols

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

The influence of sitosterol and sitostanol on the solubility of cholesterol in mixed bile salt micelles in vitro and in vivo was investigated to examine the mechanism by which sitostanol inhibits cholesterol absorption more than does sitosterol. Both sitosterol and sitostanol decreased micellar solubility of cholesterol to a similar extent, when determined with the turbidity. Also, these sterols reduced the concentration of cholesterol in micelles, both in vitro and in vivo. The extent of the reduction of micellar solubility of cholesterol by these sterols was almost the same in vitro, whereas sitostanol tended to reduce the solubility more effectively than sitosterol in vivo. Thus, the interference with cholesterol solubilization in vivo may be responsible for effective inhibition of cholesterol absorption by sitostanol. Since the effect of sitostanol was not observed in vitro, there is a possibility that another factor(s) not included in the in vitro system might affect the action of sitostanol on micellar solubility of cholesterol in vivo.

Topics: Animals; Cholesterol; Intestinal Absorption; Male; Micelles; Rats; Sitosterols; Solubility; Spectrophotometry; Ultracentrifugation

The antihypercholesterolemic activity of beta-sitosterol and beta-sitostanol was compared in male rabbits given a cholesterol-supplemented diet. beta-Sitosterol and beta-sitostanol were fed to these rabbits at the 0.5% level with cholesterol (0.5% and 0.2% in experiments I and II, respectively). The serum cholesterol level tended to be lower in rabbits fed beta-sitostanol than in the animals fed beta-sitosterol even in experiment I. The beta-sitostanol exhibited a significantly greater hypocholesterolemic activity in experiment II, LDL-cholesterol being decreased markedly. The liver cholesterol decreased in both groups of rabbits to a similar extent. beta-Sitostanol prevented more effectively the formation of dietary cholesterol-induced atheroma in the abdominal aorta than beta-sitosterol. It is most likely, together with the data reported previously on rats, that the hypocholesterolemic activity of beta-sitostanol results from the significantly greater inhibitory effect on the intestinal absorption of cholesterol than that of beta-sitosterol.

Topics: Animals; Anticholesteremic Agents; Arteriosclerosis; Cholesterol; Cholesterol, Dietary; Lipids; Lipoproteins; Liver; Male; Rabbits; Sitosterols; Sterols