Plant Sterol Concentrations Research Articles

Atherosclerotic renal artery stenosis as a cause for hypertension in an adolescent patient

Atherosclerosis causing renal artery stenosis (RAS) is one of the most common secondary causes of hypertension in adults, but is rare in children. RAS associated with coronary artery stenosis was diagnosed in a teenage patient who presented with intermittent chest pain and elevated blood pressures for 6 years. The diagnosis of RAS was suspected after physical examination revealed an abdominal bruit. Renal ultrasound with Doppler revealed normal appearing kidneys with high velocity in the aorta and renal arteries. Computed tomography angiography (CTA) of the chest and abdomen demonstrated generalized calcified atherosclerotic narrowing of the arteries including the renal, celiac, superior mesenteric and coronary arteries in the setting of hyperlipidemia. The lipid panel revealed hypercholesterolemia with elevated serum plant sterol concentrations, suggesting the diagnosis of sitosterolemia. Cardiac catheterization demonstrated left anterior descending artery and left circumflex artery stenosis, which required bypass of the left anterior descending artery and stenting of the left circumflex artery. Aggressive lipid control was recommended and he was treated medically with a beta-blocker, low-dose angiotensin-converting enzyme inhibitor, aspirin, statin, and clopidogrel. Although very rare, generalized atherosclerosis caused by genetic disorders should be considered an underlying cause for severe hypertension in children with hyperlipidemia.

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.

Phytosterols in grapes and wine, and effects of agrochemicals on their levels

To improve the knowledge on the chemical diversity and complexity of grapevine, we investigated the plant sterol content of berry and seed tissues at pre-véraison and véraison stages in 2009 and 2010. We also assessed the effects of benzothiadiazole and chitosan elicitors on content of sterols in grapes and their levels in the corresponding experimental wines. β-Sitosterol was the most abundant component in berry tissues, in both growth stages and years, with the highest amounts in the flesh and skin at pre-véraison and véraison, respectively. Stigmasterol and campesterol were present in lower concentrations in both phenological stages and vintages. During the transition from pre-véraison to véraison, phytosterols decreased in all tissues, in both years, apart from stigmasterol in seeds. In addition, the results showed that the plant activators were more effective than conventional fungicides in rising the levels of sterols, particularly β-sitosterol, both in grapes and in microvinificates.

Plasma plant sterols serve as poor markers of cholesterol absorption in man

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

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.

Extraction of Plant Sterols from Jatropha Cake

Ultrasonic assisted solvent extraction technique was applied for the extraction of plant sterols from jatropha cake,and the content of plant sterols was determined by spectrophotometry.The extracting conditions optimized by orthogonal experiment were as follows:jatropha cake of 50g, acetone of 100mL,extraction time of 1h.Under the optimal conditions,the extraction rate of plant sterols was up to 0.347%.

Plant phloem sterol content: forms, putative functions, and implications for phloem-feeding insects

All eukaryotes contain sterols, which serve as structural components in cell membranes, and as precursors for important hormones. Plant vegetative tissues are known to contain mixtures of sterols, but very little is known about the sterol composition of phloem. Plants are food for many animals, but plant-feeding arthropods (including phloem-feeding insets) are unique among animals in that they have lost the ability to synthesize sterols, and must therefore acquire these essential nutrients from their food, or via endosymbionts. Our paper starts by providing a very brief overview of variation in plant sterol content, and how different sterols can affect insect herbivores, including those specializing on phloem. We then describe an experiment, where we bulk collected phloem sap exudate from bean and tobacco, and analyzed its sterol content. This approach revealed two significant observations concerning phloem sterols. First, the phloem exudate from each plant was found to contain sterols in three different fractions – free sterols, sterols conjugated to lipids (acylated), and sterols conjugated to carbohydrates (glycosylated). Second, for both plants, cholesterol was identified as the dominant sterol in each phloem exudate fraction; the remaining sterols in each fraction were a mixture of common phytosterols. We discuss our phloem exudate sterol profiles in a plant physiology/biochemistry context, and how it relates to the nutritional physiology/ecology of phloem-feeding insects. We close by proposing important next steps that will advance our knowledge concerning plant phloem sterol biology, and how phloem-sterol content might affect phloem-feeding insects.

What is the real meaning of increased serum plant sterol concentrations?

What is the real meaning of increased serum plant sterol concentrations?

Sterol stability in functional fruit beverages enriched with different plant sterol sources

Two different plant sterol (PS) sources (free PS from tall oil and esterified PS from vegetable oils) were used for manufacturing two types of functional beverages (fruit and milk-based fruit beverages), and their PS and phytosterol oxidation product (POP) contents were determined. Gas chromatography–tandem mass spectrometry (GC–MS/MS) was used for identification and gas chromatography–flame ionization detection (GC–FID) for quantitation purposes. Brassicasterol, campesterol, campestanol, stigmasterol, β-sitosterol and sitostanol were the quantified PS, conforming a profile in order with current legislation. The relative percentages of PS differed according to the enrichment source involved, though the enrichment levels (g/100g beverage) were of the same order (1.77 from tall oil and 1.84 from vegetable oils). Only POPs from β-sitosterol (the prevalent PS in the analyzed beverages) were detected — the predominant representative being 7β-hydroxysitosterol (39–58.5% of total POP content). The following POPs were quantified: 7α-hydroxy, β-epoxy, α-epoxy, and 7-ketositosterol, yielding a total POP content ranging between 42.9 and 57.4mg/100g of PS. No statistically significant differences (p>0.05) in total and individual POP content according to the source of PS were found. The mean β-sitosterol oxidation percentage was <0.07%, which reflected a low PS oxidation extent, though manufacture was on a laboratory scale regardless of the PS source used in enrichment of the functional beverages. These functional drinks therefore can be regarded as healthy food products and as an adequate PS vehicle as well.

Serum lipids, plant sterols, and cholesterol kinetic responses to plant sterol supplementation in phytosterolemia heterozygotes and control individuals

Plant sterol (PS) supplementation is increasingly accepted as a dietary strategy to lower plasma cholesterol concentrations. However, information is scarce about the effect of increased PS intake in potentially vulnerable groups, such as phytosterolemia heterozygotes (HET). This study assessed the responsiveness of circulating PS and lipid concentrations and cholesterol kinetics (absorption and synthesis) to daily PS supplementation in HET (ABCG8 S107X mutation) compared with a healthy control cohort. A double-blind, randomized, crossover, placebo-controlled study was conducted in 10 HET and 15 control subjects. The participants had a mean (±SEM) age of 34 ± 2 y and a BMI (in kg/m²) of 29.9 ± 1.1 and consumed ∼1.6 g PS or placebo capsules daily with supper for 4 wk. Cholesterol absorption and synthesis were assessed by using [¹³C]cholesterol and deuterium oxide, respectively. Plasma LDL-cholesterol concentrations decreased (P = 0.006) in both groups after PS supplementation (HET: 2.73 ± 0.19 mmol/L; control: 3.11 ± 0.19 mmol/L) compared with placebo (HET: 3.12 ± 0.20 mmol/L; control: 3.50 ± 0.21 mmol/L), whereas PS concentrations (campesterol+β-sitosterol) increased (P = 0.03) in both groups after PS supplementation (HET: 39.72 ± 6.05 μmol/L; control: 24.03 ± 1.65 μmol/L) compared with placebo (HET: 27.32 ± 3.80 μmol/L; control: 21.12 ± 2.05 μmol/L). Cholesterol absorption efficiency decreased (P = 0.010) by ∼22% and ∼17% and synthesis rates increased (P = 0.040) by ∼20% and ∼24% in the HET and control groups, respectively, in response to PS consumption compared with placebo. These data suggest that heterozygosity for the ABCG8 S107X mutation does not influence the action of dietary PS on circulating cholesterol concentrations but may affect sterol absorption.

Dietary intake of plant sterols stably increases plant sterol levels in the murine brain

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

The lipid composition of rice cultivars with different eating qualities

Lipid composition of three rice varieties (Koshihikari, Dongjin, and Singeumo) with varying palatability was investigated. Results from both Toyo taste and sensory analyses indicated that Koshihikari, Dongjin, and Singeumo have high, medium, and low eating qualities, respectively. Koshihikari was also found to have better texture properties and higher Mg/K ratio, indicating a better eating quality. Major fatty acids found in both starch and nonstarch lipids of rice were linoleic, oleic, and palmitic acids. Dongjin contained the highest non-starch lipid content, but also had the lowest starch lipid level. Oleic acid concentrations were higher in both the high-palatable Koshihikari and low-palatable Singeumo than in Dongjin, whereas Dongjin showed high levels of palmitic and linoleic acids. Squalene, campesterol, and cycloartenol contents were substantially higher in Koshihikari than in the rice varieties with lower palatability. These findings demonstrate that rice concentrations of plant sterols, particularly cycloartenol and squalene, appear to have a positive effect on its palatability.

Plant sterols and cardiovascular disease: a systematic review and meta-analysis†

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

Serum and lipoprotein sitostanol and non-cholesterol sterols after an acute dose of plant stanol ester on its long-term consumption

Chronic inhibition of cholesterol absorption with large doses of plant stanol esters (staest) alters profoundly cholesterol metabolism, but it is unknown how an acute inhibition with a large staest dose alters the postprandial serum and lipoprotein cholesterol precursor, plant sterol, and sitostanol contents. Hypercholesterolemic subjects, randomly and double-blind divided into control (n = 18) and intervention groups (n = 20), consumed experimental diet without and with staest (plant stanols 8.8 g/day) for 10 weeks. Next morning after a fasting blood sample (0 h), the subjects had a breakfast without or with staest (4.5 g of plant stanols). Blood sampling was repeated 4 h later. Lipoproteins were separated with ultracentrifugation, and sterols were measured with gas-liquid chromatography. In 0-h chylomicrons and VLDL, plant sterols were lower in staest than in controls. Postprandially, cholestenol (cholesterol synthesis marker) was reduced in chylomicrons in staest compared with controls (-0.13 ± 0.04 μg/dL vs. 0.01 ± 0.08 μg/dL, P < 0.05). Staest decreased postprandially avenasterol in chylomicrons (P < 0.05 from 0 h). Sitostanol was high at 0 h by chronic staest in serum and VLDL but not in chylomicrons. Postprandial sitostanol was increased by staest in VLDL only. Chronic cholesterol absorption inhibition with large amount of plant stanol esters decreases plant sterols in triglyceride-rich lipoproteins. Acute plant stanol ester consumption increases sitostanol content in triglyceride-rich lipoproteins but suggests to decrease the risk of plant sterol and plant stanol accumulation into vascular wall by chylomicrons.

Increased plasma plant sterol concentrations and a heterozygous amino acid exchange in ATP binding cassette transporter ABCG5: A case report

Whilst conducting a scientific study, an elevated plasma plant sterol concentration of 3.07 mg/dL was established in one proband. Similar levels found in his mothers plasma (2.73 mg/dL) were suggestive of a heterozygous sitosterolemia. The resulting gene analysis for ATP binding cassette transporter G5/G8 (ABCG5/G8) revealed a heterozygous polymorphism in ABCG8 (Thr400Lys, rs4148217), which the proband had inherited from his father. However, a heterozygous amino acid exchange (Arg406Gln) in exon 9 of ABCG5 was revealed, which was inherited from his mother. Although not sufficient evidence exists to regard this sequence variation as a mutation, this previously unreleased sequence variation occurred in a “hot spot” area for sitosterolemia of the ABCG5 gene (exon 9) and the similar increased plasma plant sterol concentrations of the heterozygous mother contribute to the notion, that this very likely presents an inactivating mutation.

Validation of an isotope dilution gas chromatography–mass spectrometry method for analysis of 7-oxygenated campesterol and sitosterol in human serum

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

The plant sterol brassicasterol as additional CSF biomarker in Alzheimer’s disease

Plant sterols (sitosterol, campesterol, stigmasterol and brassicasterol) are solely dietary-derivable sterols that are structurally very similar to cholesterol. In contrast to peripheral cholesterol, plant sterols can cross the blood-brain barrier and accumulate within mammalian brain. As an impaired function of the cerebrospinal fluid (CSF)-blood barrier is linked to neurodegenerative disorders, i.e. Alzheimer's disease (AD), we investigated whether this results in altered plant sterol concentrations in CSF. Applying gas chromatography/mass spectrometry analysis, plant sterol concentrations were measured in plasma and CSF of patients with AD (n = 67) and controls (n = 29). Age, gender, plasma-to-CSF albumin ratio, CSF Aβ(42) , CSF pTau, APOE4 genotype, and serum creatinine were applied as covariates in the statistical analysis for individual plant sterols in order to compare plasma and CSF plant sterol concentrations between patients with AD and controls. Albumin quotient was a consistent predictor in CSF for cholesterol and methyl plant sterols campesterol and brassicasterol. Comparison of lipid parameters per diagnosis based on relevant predictors revealed significantly lower concentrations of brassicasterol (P < 0.001) in CSF of patients with AD. Binary logistic regression analysis revealed that brassicasterol improved the predictive value when added to pTau and Aβ42 in a biomarker model. Brassicasterol might be a relevant additional biomarker in AD.

The search of new biomarkers to identify Alzheimer’s disease

The study by Vanmierlo et al. (1) published in this issue of Acta Psychiatrica Scandinavica suggests that brassicasterol might be a relevant additional biomarker in Alzheimer’s disease (AD). Brassicasterol, sitosterol, campesterol and stigmasterol are all plant, exogenous, sterols that enter the body only via food intake. They are similar to cholesterol, but contrary to this one are able to cross the blood-brain barrier (BBB) and accumulate within the brain. Since the BBB and its choroid plexus have an impaired function in the early stages of AD, Vanmierlo et al. hypothesized that plant sterol concentrations in CSF are altered in AD and therefore might be relevant biomarkers for AD. The authors of this paper found that compared with controls, concentrations of plant sterols are in fact reduced in the CSF of AD patients, after controlling for relevant covariates. In both sitosterol and brassicasterol the differences were statistically significant, but remained significant only for brassicasterol when controlling for cholesterol. For a reasonable sensitivity of 85% in predicting AD, the specificity of brassicasterol was 70%, which is a remarkable performance. Furthermore, this plant steroid improved the predictive value when added to the best accepted biomarkers until now, pTau and Aß42. As the authors of this paper conclude, brassicasterol might indeed be a relevant, additional biomarker in AD. This interesting article emerges in a context of general concern about dementia, the most widespread neurodegenerative disease, and specifically about AD, the most frequent subtype (2). The clinical symptoms of AD are commonly diagnosed in older people, but there is evidence that the degenerative process starts years before the clinical onset. It has been suggested that a delay of few years before the clinical onset of AD might decrease dramatically the prevalence of the disease. Therefore, the presymptomatic detection of AD might be crucial to facilitate an early treatment before the destructive neurodegeneration occurs. The search of biomarkers to adequately identify AD in the early stages has become a focus of research interest (3). It would facilitate an early diagnosis and treatment, as well as the monitoring of disease progression and treatment response. Ideally, biomarkers should facilitate the detection of the fundamental, neuropathological features in a feasible process, and should be reliable, reproducible, non-invasive, and cheap. Furthermore, biomarkers should have adequate sensitivity, specificity and predictive value, and ideally should be validated against the gold standard of confirmed neuropathology, if possible in different, independent and sound studies (4). CSF biomarkers have special interest, since they have been reported to show the best validity coefficients to date. Aß42, total tau and phosphorilated tau have been the most promising biomarkers in this respect. While none of them has been shown to generate the diagnosis, a combination of biomarkers has the potential to improve the diagnostic specificity (5). Vanmierlo′s proposal is attractive, but new studies seem to be indispensable to confirm the clinical value of the test (1). The consensus in the field is that the findings reported in this type of research should be replicated in new, independent studies. It would also be important to test the validity of the procedure in AD cases with confirmed pathological diagnosis. Discrepant findings might be expected before laboratory procedures are adequately standardized in different centres. The clinical applicability of the new biomarker might also be hampered by the lack of equipment and experience in some laboratories, and by the invasive nature of the lumbar puncture according to criteria common in some clinics, so that ethical questions might arise before standard implementation (5). Nevertheless, an important support for the new biomarker could come from data suggesting that it shows a relationship with disease stage and/or progression, and also from new, stringent studies testing to what extent brassicasterol is able to discriminate different neurological diseases, in particular neurological diseases impairing the BBB.

Plant stanol esters lower LDL cholesterol level in statin-treated subjects with type 1 diabetes by interfering the absorption and synthesis of cholesterol

Objective We investigated the effects of plant stanol esters (STAEST) on serum cholesterol and lipoprotein lipid concentrations and serum non-cholesterol sterols in patients with type 1 diabetes who were on statin treatment. Methods In a randomized, double-blind, parallel study the intervention group ( n = 12) consumed vegetable oil-based spread enriched with STAEST (3.0 g/d of plant stanols), and the control group ( n = 12) consumed the same spread containing no added plant stanols for 4 weeks. Results Serum total, LDL and non-HDL cholesterol concentrations were decreased by 9.6, 16.4 and 15.3% compared with the baseline concentrations in the STAEST group ( P < 0.05 for all). The respective reductions were 7.8, 14.8 and 12.2% compared with the controls ( P < 0.05 for all). No effects on HDL cholesterol or serum triglyceride concentrations were found. The STAEST consumption significantly decreased serum plant sterol concentrations and the ratios to cholesterol by 30–32 and 25–27% ( P < 0.05 for all) compared with the baseline levels, respectively. Cholesterol synthesis markers were not increased in the STAEST group, but serum lathosterol to campesterol ratio was significantly increased by 57% compared with the baseline levels indicating increased cholesterol synthesis at least to some extent in compensation for decreased cholesterol absorption. However, cholesterol homeostasis, intact at baseline and in the control group also during the intervention was lost in the STAEST group. Conclusion STAEST significantly decreased serum total, LDL and non-HDL cholesterol concentrations and thus offers an additional benefit to cholesterol lowering in patients with type 1 diabetes who are on statin treatment.

Action of Plant Sterol Intervention on Sterol Kinetics in Hypercholesterolemic Men with High versus Low Basal Circulatory Plant Sterol Concentrations

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