Stanol Research Articles

Low-Fat Nondairy Minidrink Containing Plant Stanol Ester Effectively Reduces LDL Cholesterol in Subjects with Mild to Moderate Hypercholesterolemia as Part of a Western Diet

The cholesterol-lowering efficacy of plant stanol ester (STAEST) added to fat- or milk-based products is well documented. However, their efficacy when added to nondairy liquid drinks is less certain. Therefore, we have investigated the cholesterol-lowering efficacy of STAEST added to a soymilk-based minidrink in the hypercholesterolemic subjects. In a randomized, double-blind, placebo-controlled parallel study, the intervention group (n = 27) consumed 2.7 g/d of plant stanols as the ester in soymilk-based minidrink (65 mL/d) with the control group (n = 29) receiving the same drink without added plant stanols once a day with a meal for 4 weeks. Serum total, LDL, and non-HDL cholesterol concentrations were reduced by 8.0, 11.1, and 10.2% compared with controls (P < 0.05 for all). Serum plant sterol concentrations and their ratios to cholesterol declined by 12–25% from baseline in the STAEST group while the ratio of campesterol to cholesterol was increased by 10% in the controls (P < 0.05 for all). Serum precursors of cholesterol remained unchanged in both groups. In conclusion, STAEST-containing soymilk-based low-fat minidrink consumed once a day with a meal lowered LDL and non-HDL cholesterol concentrations without evoking any side effects in subjects consuming normal Western diet. The clinical trial registration number is NCT01716390.

Clinical Practice Guidelines for Healthy Eating for the Prevention and Treatment of Metabolic and Endocrine Diseases in Adults: Cosponsored by the American Association of Clinical Endocrinologists/The American College of Endocrinology and the Obesity Society Executive Summary

J. Michael Gonzalez-Campoy, MD, PhD, FACE1; Sachiko T. St. Jeor, PhD, RD2; Kristin Castorino, DO3; Ayesha Ebrahim, MD, FACE4; Dan Hurley, MD, FACE5; Lois Jovanovic, MD, MACE6; Jeffrey I. Mechanick, MD, FACP, FACN, FACE, ECNU7; Steven M. Petak, MD, JD, MACE, FCLM8; Yi-Hao Yu, MD, PhD, FACE9; Kristina A. Harris10; Penny Kris-Etherton, PhD, RD11; Robert Kushner, MD12; Maureen Molini-Blandford, MPH, RD13; Quang T. Nguyen, DO14; Raymond Plodkowski, MD15; David B. Sarwer, PhD16; Karmella T. Thomas, RD17

Results from a post-launch monitoring survey on consumer purchases of foods with added phytosterols in five European countries

Phytosterols (plant sterols and stanols), in the form of phytosterol-esters, are used in food products as active ingredients to lower elevated blood low density lipoprotein-cholesterol concentrations. In Europe, plant sterol-esters gained Novel Foods authorisation in 2000. As a requirement of the authorisation, Unilever developed a post-launch monitoring program to monitor the use of products with added phytosterols. This paper reports findings from the 2011 post-launch monitoring survey on consumer purchase behaviour of foods with added phytosterols. 91,000 households in the Netherlands, Belgium, United Kingdom, France and Germany were included. 11,612 purchased foods with added phytosterols, including spreads, salad dressings, milk- and yoghurt-type products. The results show that 71-82% of households purchasing products with added phytosterols were 1-2 person households. These households were also purchasing the majority of the volume sold in each country (75-85%). The average phytosterol intakes per household were 0.35-0.86 g/day; well below the 1.5-3.0 g/day phytosterols needed to achieve a significant blood cholesterol lowering benefit. Post-launch monitoring is an accepted and useful tool to estimate the consumption behaviour amongst different consumer groups. Data show that average phytosterol intakes per household were well below 1g/day, suggesting that overconsumption is unlikely.

Degradation of phytosterols during storage of enriched margarines

Oxidative changes of phytosterols were recently studied in vegetable oils and some food products. Cholesterol-lowering properties of phytosterols and phytostanols are the main driver for formulating functional foods containing these compounds.Margarines enriched in plant stanols were stored at two typical temperatures for up to 18weeks. Analysed margarines contained four phytosterols: brassicasterol, campesterol, sitosterol, avenasterol and two phytostanols: sitostanol, campestanol. The content of phytosterols and phytostanols in margarines changed from 79mg/g in a control sample to 63mg/g and 55mg/g in samples stored for 18weeks at 4°C and 20°C, respectively. At the end of storage, contents of sitostanol decreased by 23% and 30%, while the amounts of oxidised sterols increased by 35% and 100%, respectively, for both temperatures. 7-Hydroxy derivatives dominated among all oxidised phytosterols and their content increased threefold at the end of storage. Epoxy derivatives exhibited a maximum after 6weeks of storage at 20°C and thereafter decreased constantly.

The effects of plant stanol ester consumption on arterial stiffness and endothelial function in adults: a randomised controlled clinical trial

BackgroundThe hypocholesterolemic effect of plant stanol ester consumption has been studied extensively, but its effect on cardiovascular health has been less frequently investigated. We studied the effects of plant stanol esters (staest) on arterial stiffness and endothelial function in adults without lipid medication.MethodsNinety-two asymptomatic subjects, 35 men and 57 women, mean age of 50.8±1.0 years (SEM) were recruited from different commercial companies. It was randomized, controlled, double-blind, parallel trial and lasted 6 months. The staest group (n=46) consumed rapeseed oil-based spread enriched with staest (3.0 g of plant stanols/d), and controls (n=46) the same spread without staest. Arterial stiffness was assessed via the cardio-ankle vascular index (CAVI) in large and as an augmentation index (AI) in peripheral arteries, and endothelial function as reactive hyperemia index (RHI). Lipids and vascular endpoints were tested using analysis of variance for repeated measurements.ResultsAt baseline, 28% of subjects had a normal LDL cholesterol level (≤3.0 mmol/l) and normal arterial stiffness (<8). After the intervention, in the staest group, serum total, LDL, and non-HDL cholesterol concentrations declined by 6.6, 10.2, and 10.6% compared with controls (p<0.001 for all). CAVI was unchanged in the whole study group, but in control men, CAVI tended to increase by 3.1% (p=0.06) but was unchanged in the staest men, thus the difference in the changes between groups was statistically significant (p=0.023). AI was unchanged in staest (1.96±2.47, NS) but increased by 3.30±1.83 in controls (p=0.034) i.e. the groups differed from each other (p=0.046). The reduction in LDL and non-HDL cholesterol levels achieved by staest was related to the improvement in RHI (r=−0.452, p=0.006 and −0.436, p=0.008).ConclusionsLowering LDL and non-HDL cholesterol by 10% with staest for 6 months reduced arterial stiffness in small arteries. In subgroup analyses, staest also had a beneficial effect on arterial stiffness in large arteries in men and on endothelial function. Further research will be needed to confirm these results in different populations.Trial registrationClinical Trials Register # NCT01315964

The cholesterol lowering efficacy of plant stanol ester yoghurt in a Turkish population: a double-blind, placebo-controlled trial

BackgroundWe evaluated the cholesterol lowering efficacy of low-fat spoonable yoghurt with 1.9 g/d plant stanols as esters on plasma lipid profiles of Turkish subjects with mild to moderate hypercholesterolemia.MethodsUsing a randomised, double-blind, placebo-controlled study design, intervention (n = 35) and control (n = 35) groups consumed either 115 g low-fat yoghurt with 1.9 g/d plant stanols as esters or placebo yoghurt, respectively, for 4 weeks. Seventy subjects with untreated mild to moderate hypercholesterolemia (aged 23-65 years) were recruited. Changes in the lipid profile, including lipoproteins, apolipoproteins, and triglycerides, and anthropometric measurements were monitored at screening, baseline, and at the end of the second, third, and fourth weeks of intervention. The general linear model repeated measures procedure was used to test differences in the repeated continuous variables between study groups.ResultsSerum total cholesterol (4.6%), LDL cholesterol (6.3%), and non-HDL cholesterol (6.2%) concentrations were reduced significantly from baseline in the plant stanol group compared to the control group (p = 0.007, p = 0.005 and p = 0.005, respectively). A variation in the response of serum total and LDL cholesterol between the subjects in plant stanol group was obtained. No clinically significant change in anthropometrical measurements was observed during the intervention.ConclusionsThe spoonable low-fat yoghurt with 1.9 g/d plant stanols as esters lowered total, LDL, and non-HDL cholesterol levels in Turkish subjects with mild to moderate hypercholesterolemia. Nevertheless variation in baseline cholesterol levels, genetic predisposition of the subjects and compliance may contribute to a large individual variability.

The effect of enriching milk‐based beverages with plant sterols or stanols on the fatty acid composition of the products

Five plant sterol (PS)‐enriched dairy products from the Spanish market were characterised for fatty acids (FA), volatile compounds and lipid stability. The ingredients used for PS enrichment by the food industry may come from different sources, thus influencing the composition and stability of the lipid fraction. In this study, the FA profile proved highly variable among samples, not agreeing with the nutritional labelling of the products. The volatile profile was characterised. A total of 55 volatile compounds were identified in the samples by GC–MS. Concentrations of hexanal (from 1.1 to 7.5 ng/g), nonanal (from 0.9 to 1.2 ng/g) and decane (from n.d. to 11.9 ng/g) indicated a low lipid oxidation extent. Peroxide value, ranking between 0.7 and 3.2 meq of active oxygen per kilogram of fat, except sample with fish oil, where peroxide value was 7.7 meq of active oxygen per kilogram of fat, and thiobarbituric acid reactive species, from 2 to 21 μg malondialdehyde (MDA)/g of fat, were in the lower limits of the ranges found in the literature.

Scientific Opinion on the substantiation of a health claim related to the consumption of 2 g/day of plant stanols (as plant stanol esters) as part of a diet low in saturated fat and a two‐fold greater reduction in blood LDL‐cholesterol concentrations compared to the consumption of a diet low in saturated fat alone pursuant to Article 14 of Regulation (EC)

Following an application from McNeil Nutritionals and Raisio Nutrition Ltd, submitted for authorisation of a health claim pursuant to Article 14 of Regulation (EC) No 1924/2006 via the Competent Authority of the United Kingdom, the Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver an opinion on the scientific substantiation of a health claim related to the consumption of 2 g/day of plant stanols (as plant stanol esters) as part of a diet low in saturated fat and a two-fold greater reduction in blood LDL-cholesterol concentrations compared to the consumption of a diet low in saturated fat alone. The food that is the subject of the health claim, plant stanol esters, is sufficiently characterised. The applicant provided five human intervention studies for the scientific substantiation of the claim. The Panel notes that the design of the studies submitted did not allow an evaluation of the quantitative effects of diets low in saturated fat per se on blood LDL-cholesterol concentrations. Therefore, the effect of consuming 2 g/day plant stanols as part of a diet low in saturated fat relative to the effect of consuming a diet low in saturated fat alone cannot be determined on a quantitative basis. The Panel considers that the evidence provided by the applicant does not establish that the consumption of 2 g/day of plant stanols (as plant stanol esters) as part of a diet low in saturated fat results in a two-fold greater reduction in LDL-cholesterol concentrations compared with consuming a diet low in saturated fat alone. A claim on plant stanol esters and reduction of blood LDL-cholesterol concentrations (irrespective of the background diet) has already been authorised in the European Union.

Oxyphytosterol formation in humans: Identification of high vs. low oxidizers

Animal studies suggest that oxyphytosterols are atherogenic. However, we have previously shown that plasma oxyphytosterol concentrations did not increase after consuming a diet enriched in plant sterol esters (3g/day), while minor reductions were seen after consuming a plant stanol ester-enriched diet. Large variations in oxyphytosterol concentrations between individuals however existed. The aim of this study was to identify factors that may explain inter-individual differences in plasma oxyphytosterol concentrations. For this, 43 subjects consumed for 4 weeks in random order a plant sterol, stanol and control margarine. Plasma oxyphytosterol concentrations were determined in butylated hydroxytoluene (BHT)-enriched EDTA plasma via GC–MS and serum oxidized low-density lipoprotein (oxLDL) concentrations were analyzed via ELISA. Trolox equivalent antioxidant capacity (TEAC) values, α-tocopherol concentrations and iron/copper status were determined to assess plasma oxidative and anti-oxidative capacity. Serum (non-oxidized) sitosterol and campesterol concentrations did not correlate with plasma oxysitosterol and oxycampesterol concentrations during any of the three dietary interventions. Moreover, plasma oxyphytosterol concentrations remained relatively stable over time. Six subjects could be arbitrarily classified as having consistent low or high plasma oxyphytosterol concentrations, which was also reflected in oxLDL concentrations. However, oxidative and anti-oxidative capacity markers, such as iron/copper status, α-tocopherol concentrations and TEAC values, could not explain these differences. In conclusion, subjects seem to have consistent plasma oxyphytosterol concentrations, which resulted in the identification of ‘low and high oxidizers’. Differences, however, could not be attributed to the oxidative and anti-oxidative capacity markers analyzed.

Role of plant stanol derivatives in the modulation of cholesterol metabolism and liver gene expression in mice

The present study was to evaluate the cholesterol-lowering effect of two novel plant stanol derivatives and its potential molecular mechanism in hyper-cholesterol mice induced by a high-cholesterol diet. Results showed that oral administration of plant stanyl hemisuccinate (2×, 5×) and plant stanyl sorbitol succinate (2×, 5×) effectively attenuated the serum total cholesterol and low density lipoprotein cholesterol levels, while had no effect on the serum triacylglycerol and high density lipoprotein cholesterol. And plant stanol derivatives decreased liver cholesterol concentration and increased faecal cholesterol output. Meanwhile, both plant stanyl hemisuccinate and plant stanyl sorbitol succinate could remarkably promote liver X receptor alpha (LXRα) expression, and increased cholesterol 7α-hydroxylase (CYP7A1) expression and faecal total bile acid output to varying degrees. These results suggested two novel plant stanol derivatives possessed hypocholesterolemic effect, and the cholesterol-lowering action of plant stanol derivatives may be through activating the potential LXRα-CYP7A1-bile acid excretion pathway.

A Prospective Randomized Trial for Reduction of Serum Low Density Lipoprotein (LDL) with Plant Stanol Ester Mixed in Coffee in a Hypercholesterolemic Thai Population.

OBJECTIVE: To determine whether replacing ordinary coffee with coffee mixed with the plant stanol ester decreases the serum low density lipoprotein (LDL) level in moderately hypercholesterolemic Thais. MATERIALS AND METHODS: A randomized, double-blind, placebo-controlled trial of a common daily coffee was conducted on May 1, 2012 with continued treatment and follow-up through June 1, 2012. A total of 54 Thais whose serum LDL levels ranged from 130 to 239 mg/dL at randomization, were enrolled and randomized into two groups. The participants consumed a cup of plant stanol mixed coffee or a cup of placebo coffee once a day. The percentage of serum LDL reduction was measured at the end of the study. RESULTS: Thirty-three subjects were randomized into each group. Forty-seven subjects completed the study, 30 in the group receiving coffee with added plant stanols as ester and 17 in the placebo coffee group. Statistical analysis was done by unpaired t-test using PASW (Predictive Analytics SoftWare) Statistics 18 (SPSS Inc., IL, USA). The results showed a signifi cant difference in mean reduction of LDL levels (p &lt; 0.001, 95% CI = 6.92 – 18.57). The means were 12.77% in the fi rst group and 0.03% in the second group (SD = 9.33 and 9.88, respectively). CONCLUSION: Among this population of hypercholesterolemic Thais, the daily replacement of an ordinary cup of coffee with a plant stanol mixed coffee reduced serum LDL levels by 12.77% demonstrating the effi cacy of the cholesterol-lowering ingredient in the new food matrix.

Supplemental plant sterols and stanols for serum cholesterol and cardiovascular disease

This is the protocol for a review and there is no abstract. The objectives are as follows: To determine the effects of phytosterols, phytostanols or their esters, ingested in supplemented foods, on blood cholesterol concentrations and cardiovascular disease;To look for adverse effects e.g. on nutritional status or physiological function;To study/comment on, possible effects of cost.

Effects of plant sterol- or stanol-enriched margarine on fasting plasma oxyphytosterol concentrations in healthy subjects

BackgroundConsumption of plant sterols and plant stanols reduces low-density lipoprotein cholesterol (LDL-C) concentrations. At the same time, plasma plant sterol concentrations will increase after plant sterol consumption, but decrease after plant stanol consumption. In contrast to plant stanols, plant sterols can undergo oxidation and form oxyphytosterols. Findings from in vitro and animal studies suggest that oxyphytosterols might be atherogenic. ObjectiveThe objective was to examine whether plant sterol and stanol consumption changes fasting plasma oxyphytosterol concentrations. DesignA randomized, double blind, cross-over study was performed in which 43 healthy subjects (18–70 years) consumed for 4 weeks a plant sterol-enriched (3.0 g/d of plant sterols), a plant stanol-enriched (3.0 g/d of plant stanols), and a control margarine separated by wash-out periods of 4 weeks. Oxyphytosterol concentrations were determined in BHT-enriched plasma via GC–MS. ResultsCompared to control, serum LDL-C concentrations were reduced after plant sterol (−8.1%; p < 0.001) and plant stanol consumption (−7.8%; p < 0.001). Plant sterol consumption did not change plasma oxyphytosterol concentrations. On the other hand, intake of the plant stanol margarine reduced 7β-OH-campesterol by 0.07 ng/mL (∼14%; p < 0.01) and by 0.07 ng/mL (∼15%; p < 0.01) compared with the control and sterol margarines, respectively. When standardized for serum cholesterol, effects on these oxyphytosterols were comparable. In addition, plant stanol intake reduced cholesterol-standardized 7-keto-campesterol levels compared with plant sterol intake (p < 0.05). ConclusionsDaily consumption of a plant sterol-enriched margarine does not increase oxyphytosterol concentrations, while plant stanol consumption may reduce the concentrations of the oxidative plant sterol metabolites 7β-OH-campesterol and 7-keto-campesterol. This trial is registered at clinicaltrials.gov as NCT01559428.

The Role of Phytosterols Enriched Foods-A Review

Phytosterols exist as naturally occurring plant sterols that are present in the nonsaponifiable fraction of plant oils. Phytosterols (plant sterols and stanols) are well known for their low density lipoprotein- cholesterol (LDL-C)-lowering effect. Although many studies have been conducted to resolve the mechanisms of action by which phytosterols lower serum cholesterol. Dietary Phytosterols appear to play an important role in the regulation of oxidation and serum lipids and exhibit anticancer properties. However, as the study confines to the effect of phytosterol on lipid regulation, the review is confined to phytosterol and their role in control of cardiovascular disease (CVD). The information reviewed is presented under the following sections as types of Phytosterols and their structures, mechanism of action, phytosterols in foods for cvd risk reduction, phytosterols as ingredient in functional foods, stability of phytosterols in foods, safety aspects and regulatory status of phytosterols, phytosterols content in foods and phytosterol enriched products are reviewed.

An update on statin alternatives and adjuncts

LDL cholesterol is the primary target of therapy to lower cardiovascular risk. Statins are medications of first choice to lower LDL cholesterol, but cannot be tolerated in up to 10% of individuals. Intermittent dosing strategies for statins can help reduce muscle symptoms in some patients. A Mediterranean-type diet supplemented with plant stanols and sterols, fiber and fish oils can help achieve cholesterol goals and reduce cardiovascular events. Caution may be needed when using supplements, such as red yeast rice, because of the concern regarding contaminants. Other lipid-lowering medications, such as intestinal agents, niacin and fibrates, can be used as alternative strategies in patients who cannot tolerate statins or in combination with low-dose statins to achieve lipid goals and reduce cardiovascular risk.

Dose-dependent LDL-cholesterol lowering effect by plant stanol ester consumption: clinical evidence

Elevated serum lipids are linked to cardiovascular diseases calling for effective therapeutic means to reduce particularly LDL-cholesterol (LDL-C) levels. Plant stanols reduce levels of LDL-C by partly blocking cholesterol absorption. Accordingly the consumption of foods with added plant stanols, typically esterified with vegetable oil fatty acids in commercial food products, are recommended for lowering serum cholesterol levels. A daily intake of 1.5 to 2.4 g of plant stanols has been scientifically evaluated to lower LDL-C by 7 to 10% in different populations, ages and with different diseases. Based on earlier studies, a general understanding is that no further reduction may be achieved in intakes in excess of approximately 2.5 g/day. Recent studies however suggest that plant stanols show a continuous dose–response effect in serum LDL-C lowering. This review discusses the evidence for a dose-effect relationship between plant stanol ester consumption and reduction of LDL-C concentrations with daily intakes of plant stanols of 4 g/day or more. We identified five such studies and the overall data demonstrate a linear dose-effect relationship with the most pertinent LDL-Cholesterol lowering outcome, 18%, achieved by a daily intake of 9 to 10 g of plant stanols. Along with reduction in LDL-C, the studies demonstrated a decrease in cholesterol absorption markers, the serum plant sterol to cholesterol ratios, by increasing the dose of plant stanol intake. None of the studies with daily intakes up to 10 g of plant stanols reported adverse clinical or biochemical effects from plant stanols. In a like manner, the magnitude of decrease in serum antioxidant vitamins was not related to the dose of plant stanols consumed and the differences between plant stanol ester consumers and controls were minor and insignificant or nonexisting. Consumption of plant stanols in high doses is feasible as a range of food products are commercially available for consumption including spreads and yoghurt type drinks. In conclusion, a dose-effect relationship of plant stanols in higher doses than currently recommended has been demonstrated by recent clinical studies and a meta-analysis. Further studies are called for to provide confirmatory evidence amenable for new health claim applications and dietary recommendations.

Beneficial Effects of Sitostanol on the Attenuated Immune Function in Asthma Patients: Results of an In Vitro Approach

BackgroundIn vitro and animal studies have suggested that plant sterols and stanols increase cytokine production by T-helper-1 cells. This may be beneficial for patient groups characterized by a T-helper-2 dominant immune response, e.g. asthma patients. (1) to evaluate whether sitostanol induces a T-helper-1 shift in peripheral blood mononuclear cells (PBMCs) from asthma patients, and (2) to unravel the role of regulatory T-cells in this respect.Methodology/Principal FindingsPBMCs from 10 asthma patients and 10 healthy subjects were isolated and incubated with 1.2 µM sitostanol, while stimulated with 5 µg/ml PHA. Similar amounts of cholesterol were used to determine whether effects were specific for plant stanols or for sterols in general. Changes in cytokine production were measured using antibody arrays and ELISAs. Changes in regulatory T-cell population size were measured by flow cytometry, using intracellular Foxp3 staining. Sitostanol increased production of IFNγ by 6.5% and IL-2 by 6.0% compared to cholesterol (p<0.01). No changes in IL-4 and IL-13 were found. Interestingly, this effect was only present in PBMCs from asthma patients. The number of Foxp3+ cells tended to increase and their activity, measured by IL-10 production, increased after sitostanol treatment in PBMCs from asthma patients compared to controls by 32.3% (p = 0.077) and 13.3% (p<0.05), respectively.Conclusions/SignificanceAltogether, the sitostanol-induced Thelper-1 shift in PBMCs from asthma patients and the stimulating effects of sitostanol on Treg cell numbers and activity indicate a possible novel approach for plant stanol ester enriched functional foods in the amelioration of asthmatic symptoms. Functional effects, however, require further evaluation.

Food combinations for cholesterol lowering

Reducing elevated LDL-cholesterol is a key public health challenge. There is substantial evidence from randomised controlled trials (RCT) that a number of foods and food components can significantly reduce LDL-cholesterol. Data from RCT have been reviewed to determine whether effects are additive when two or more of these components are consumed together. Typically components, such as plant stanols and sterols, soya protein, β-glucans and tree nuts, when consumed individually at their target rate, reduce LDL-cholesterol by 3-9%. Improved dietary fat quality, achieved by replacing SFA with unsaturated fat, reduces LDL-cholesterol and can increase HDL-cholesterol, further improving blood lipid profile. It appears that the effect of combining these interventions is largely additive; however, compliance with multiple changes may reduce over time. Food combinations used in ten 'portfolio diet' studies have been reviewed. In clinical efficacy studies of about 1month where all foods were provided, LDL-cholesterol is reduced by 22-30%, whereas in community-based studies of >6 months' duration, where dietary advice is the basis of the intervention, reduction in LDL-cholesterol is about 15%. Inclusion of MUFA into 'portfolio diets' increases HDL-cholesterol, in addition to LDL-cholesterol effects. Compliance with some of these dietary changes can be achieved more easily compared with others. By careful food component selection, appropriate to the individual, the effect of including only two components in the diet with good compliance could be a sustainable 10% reduction in LDL-cholesterol; this is sufficient to make a substantial impact on cholesterol management and reduce the need for pharmaceutical intervention.

Plant stanols induce intestinal tumor formation by up-regulating Wnt and EGFR signaling in ApcMin mice

The rate of APC mutations in the intestine increases in middle-age. At the same period of life, plant sterol and stanol enriched functional foods are introduced to diet to lower blood cholesterol. This study examined the effect of plant stanol enriched diet on intestinal adenoma formation in the ApcMin mouse. ApcMin mice were fed 0.8% plant stanol diet or control diet for nine weeks. Cholesterol, plant sterols and plant stanols were analyzed from the caecum content and the intestinal mucosa. Levels of β-catenin, cyclin D1, epidermal growth factor receptor (EGFR) and extracellular signal-regulated kinase 1/2 (ERK1/2) were measured from the intestinal mucosa by Western blotting. Gene expression was determined from the intestinal mucosa using Affymetrix and the data were analyzed for enriched categories and pathways. Plant stanols induced adenoma formation in the small intestine, however, the adenoma size was not affected. We saw increased levels of nuclear β-catenin, phosphorylated β-catenin (Ser675 and Ser552), nuclear cyclin D1, total and phosphorylated EGFR and phosphorylated ERK1/2 in the intestinal mucosa after plant stanol feeding. The Affymetrix data demonstrate that several enzymes of cholesterol synthesis pathway were up-regulated, although the cholesterol level in the intestinal mucosa was not altered. We show that plant stanols induce adenoma formation by activating Wnt and EGFR signaling. EGFR signaling seems to have promoted β-catenin phosphorylation and its translocation into the nucleus, where the expression of cyclin D1 was increased. Up-regulated cholesterol synthesis may partly explain the increased EGFR signaling in the plant stanol-fed mice.

Efficient Solvent-Free Synthesis of Phytostanyl Esters in the Presence of Acid-Surfactant-Combined Catalyst

An efficient approach based on the synthesis of phytostanyl esters with an acid-surfactant-combined catalyst in a solvent-free system was developed. The effect of catalyst dose, substrate molar ratio, reaction temperature, and acyl donor was considered. The reaction conditions were further optimized by response surface methodology, and a high yield of phytostanyl laurate (>92%) was obtained under optimum conditions: 3.17:1 molar ratio of lauric acid to plant stanols, 4.01% catalyst dose (w/w), 119 °C, and 4.1 h. FT-IR, MS, and NMR were adopted to confirm the chemical structure of phytostanyl laurate. Meanwhile, the physiochemical properties of different phytostanyl esters were investigated. Compared with phytostanols, the prepared phytostanyl esters had much lower melting temperature and higher oil solubility. There was no obvious difference in melting and solidification properties between sunflower oil with phytostanyl laurate (<5%) or oleate (<10%) and the original sunflower oil, suggesting that the esterification of phytostanols greatly facilitated their corporation into oil-based foods.