Plant sterols and stanols

Anti-inflammatory β-sitosterols from the Asiatic loop-root mangrove Rhizophora mucronata attenuate 5-lipoxygenase and cyclooxygenase-2 enzymes

Four biogenic β-sitosterol analogues were identified from methanolic extract of the leaves of loop-root mangrove Rhizophora mucronata. These were characterized as 4, 14, 23-trimethyl-3β-sitosterol (1), 7-ethyl-3β-sitosterol (2), sitosteryl-3β-(3³E)-pent-3³-enoate (3) and 12α-hydroxy-3β-sitosterol (4) based on comprehensive spectroscopic techniques. Anti-inflammatory activities of β-sitosterol 4 against pro-inflammatory enzymes 5-lipoxygenase and cyclooxygenase-2 were found to be significantly higher (IC₅₀ 1.85 and 1.92 mM, respectively) compared to those demonstrated by compounds of 1-3 (p < 0.05). These β-sitosterol analogues disclosed superior selectivity indices (1.43-2.07) with regard to inducible cyclooxygenase-2 than its constitutive isoform cyclooxygenase-1, when compared to the standard, ibuprofen (0.44). Antioxidant properties of 12α-hydroxy-β-sitosterol (4) were found to be significantly greater (IC₅₀ 1.43-1.67 mM) than those of other sitosterol analogues. Structure-activity correlation analyses put forward that the bioactive potencies of the titled β-sitosterols were positively correlated to their electronic parameters. Molecular docking simulations were carried out in the active sites of 5-lipoxygenase/cyclooxygenase-2, and the docking scores and binding energies of the studied β-sitosterol analogues were positively correlated with their attenuation properties against 5-lipoxygenase and cyclooxygenase-2.

β-Sitosterol-2-hydroxypropyl-β-cyclodextrin inclusion complex: Characterization and inhibitory effect on adipogenesis in 3T3-L1 pre-adipocytes

β-Sitosterol (Sit) has been used as a functional food additive. Among its many beneficial effects, this phytosterol plays a role in controlling obesity by inhibiting the adipogenesis process of pre-adipocytes. However, the highly lipophilic character of Sit limits its bioavailability. In the present study, 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) was used to form a complex with Sit, namely the Sit-HP-β-CD inclusion complex, and the inhibitory effect of this complex on adipogenesis in the 3T3-L1 pre-adipocyte cell line was investigated. The results of DSC, TLC, ¹H NMR spectroscopy, and 2D ROESY showed that the Sit-HP-β-CD inclusion complex was successfully synthesized. In addition, the inhibitory effect of the Sit-HP-β-CD inclusion complex on adipogenesis was evaluated using the Oil Red O staining method and western blot analysis after a 14-day adipogenesis induction in 3T3-L1 pre-adipocytes. The results showed that the Sit-HP-β-CD inclusion complex had a higher efficiency than Sit in reducing intracellular lipid accumulation and the expression levels of PPARγ and FAS in 3T3-L1 cells, suggesting that the inhibitory effect on adipogenesis was improved by the formation of the Sit and HP-β-CD complex.

Effects on oral fat load of a nutraceutical combination of fermented red rice, sterol esters and stanols, curcumin, and olive polyphenols: A randomized, placebo controlled trial

BACKGROUND

In literature, there are several studies about the effects of nutraceutical combinations at fasting, but data in post-prandial phase are lacking.

PURPOSE

We planned a study to evaluate the efficacy and safety of a nutraceutical agent containing fermented red rice, phytosterols and olive polyphenols compared to placebo in a sample of Caucasian patients with low cardiovascular risk, both at fasting and after an oral fat load.

STUDY DESIGN

Eighty patients were randomized to receive, as addition to diet and physical activity, a nutraceutical combination containing fermented red rice, sterol esters and stanols, curcumin, and olive polyphenols or placebo (control group), once a day.

METHODS

We evaluated at baseline, and after 3 months: body mass index, fasting plasma glucose, lipid profile, soluble intercellular adhesion molecule-1, soluble vascular cell adhesion molecule-1, and soluble endothelial-leukocyte adhesion molecule-1. We evaluated these parameters both at fasting, and after an oral fat load.

RESULTS

Nutraceutical combination gave a reduction of total cholesterol, triglycerides, and low-density lipoprotein cholesterol, both compared to baseline (p < 0.05 for all), and to placebo (p < 0.05 for all). We recorded a reduction of soluble intercellular adhesion molecule-1, soluble vascular cell adhesion molecule-1, and sE-selectin in the group treated with nutraceutical combination, both compared to baseline (p < 0.05 for all), and to placebo (p < 0.05 for all). Parameters recorded during oral fat load improved compared to the oral fat load performed at baseline with the nutraceutical combination.

CONCLUSIONS

The nutraceutical combination of fermented red rice, sterol esters and stanols, curcumin, and olive polyphenols seems to be effective in improving lipid profile and markers of endothelial damage in dyslipidemic patients in primary prevention at low risk for developing cardiovascular disease. The true novelty of this study, however, is the improvement of endothelial damage after an oral fat load compared to placebo.

Conifer Green Needle Complex in Patients with Precancerous Gastric Lesions: An Observational Pilot Study

Objectives. Helicobacter pylori infection is common and can lead to precancerous gastric lesions. Standard antibiotic therapy has a failure rate of more than 25% from antibiotic resistance. The primary aim of this observational pilot study was to test the feasibility of a large-scale clinical trial of Conifer Green Needle Complex (CGNC) to treat precancerous gastric lesions. Secondary aims were to investigate H. pylori infection, stomach function, and histopathology of the gastric mucosa. Methods. A tablet form of CGNC (extracted from Pinus sylvestris and Picea abies (L) Karst) was prescribed to 26 patients with precancerous gastric lesions (two tablets, 100 mg CGNC/tablet, three times per day for six months). Another 24 patients received no treatment. Results. Compared with control patients, CGNC-treated patients showed total or partial regression (using the quantitative Rome III diagnostic criteria) of dyspeptic symptoms (92.3%, p < 0.0001), eradication of H. pylori infection (57.1%, p < 0.03), a reduction in endoscopic signs of gastritis (92.3%, p < 0.001), an increase of pepsinogen-pepsin in the gastric juice (57.7%, p < 0.05), and total regression or reduction in the degree of intestinal metaplasia (46.2%, p < 0.05) and lymphoplasmacytic infiltration (53.8%, p < 0.05). Conclusions. This study justifies a randomised-controlled trial with CGNC in patients with atrophic gastritis.

Reconstructing long-term trends in municipal sewage discharge into a small lake in northern Manitoba, Canada

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.

Key points for maximum effectiveness and safety for cholesterol-lowering properties of plant sterols and use in the treatment of metabolic syndrome

According to the American Diabetes Association and the Adult Treatment Panel III, the starting point for treating metabolic syndrome (MS) is a change of lifestyle. In addition, action on the main symptoms of MS by means of dietary supplements, can be helpful in view of the chronic course of the disease. The term 'phytosterols' refers to sterols and stanols composed of lipophilic triterpenes, a family that is widely distributed in the plant kingdom and whose cholesterol-lowering properties have been amply demonstrated. In the light of the recent literature, the key points for maximum effectiveness and safety of sterols are the following. (A) Plant sterols should be taken with meals: clinical trials have shown that when plant sterols are consumed close to mealtimes, low-density lipoprotein cholesterol may decrease by 9.4%, while when they are taken between meals, the reduction is about 6%. (B) The optimal dosage is 2-2.5 g day(-1) in a single dose. More than 3 g day(-1) has not been found to have any additional beneficial effect and increases the risk of side effects. (C) The food matrix used to dissolve the phytosterols should contain a certain amount of fat. A milk-based matrix appears optimal from this point of view.

Fortification of vitamin A in a phytosterol enriched milk maintains plasma beta-carotene levels

The aim of the current study was to investigate if the supplementation of vitamin A via a phytosterol enriched low-fat milk could prevent the reduction of plasma beta-carotene concentrations than often occurs after plant sterols' or stanols' intake. A sample of 108 hypercholesterolaemic adults (40-60 years old) was randomized to an enriched milk group that contained among other nutrients phytosterols (0.5 g/100 ml) and vitamin A (111 μg/100 ml) (EMG: n = 40), a placebo plain milk group (PMG: n = 37), and a control group (CG: n = 31) following their usual diet; the EMG and the PMG consumed 500 ml milk per day and in order to ensure compliance with the intervention scheme, attended health and nutrition counselling sessions biweekly over a 3-month period. Dietary intake of vitamin A significantly increased in the EMG compared to the PMG and the CG (P < 0.001) and all groups significantly increased their vegetable consumption. However, no significant differences were found among groups regarding changes in dietary intake of beta-carotene and consumption of fruits. Regarding biochemical indices, total cholesterol, LDL-cholesterol and apolipoprotein-B decreased significantly within all study groups, with the decreases being significantly higher in the EMG compared to the CG (-25.4 vs. -9.9; -21.7 vs. -8.2 and -13.2 vs. -3.4 mg/dl, respectively; P < 0.05). Plasma concentrations of beta-carotene did not change in any of the three groups. Extra fortification of a phytosterol enriched milk with vitamin A seems to be useful in maintaining plasma beta-carotene levels of hypercholesterolemic adults after consumption of 2.5 g/d of phytosterols over a 3-month intervention period.

The effect of high-fiber rye bread enriched with nonesterified plant sterols on major serum lipids and apolipoproteins in normocholesterolemic individuals

BACKGROUND AND AIMS

Plant sterols are naturally occurring cholesterol-lowering compounds which are industrially incorporated in various foods. A novel food carrier is rye bread, the intake of which can be monitored in trials utilizing newly defined plasma biomarkers. Our aim was to determine the effects of plant sterols incorporated into high-fiber rye bread on serum total and LDL cholesterol, apoB/apoA1 and total cholesterol/HDL cholesterol ratios and lipophilic (pro)vitamins in healthy free-living normocholesterolemic individuals.

METHODS AND RESULTS

In this double-blind, dietary intervention trial the subjects (n=68) were randomized to receive a rye bread (9.3g/d fiber) with added plant sterols (2g/d) (active) or without (control). In the second phase of the study the amount of rye bread was doubled providing 18.6g/d fiber and in the active group 4g/d plant sterols. Compliance was monitored utilizing 3-day food diaries and a novel rye fiber-derived biomarker in plasma. Intake of rye bread enriched with 2g/d of plant sterols during two weeks reduced significantly serum total and LDL cholesterol, apoB/apoA1 and total cholesterol/HDL cholesterol ratios by 5.1%, 8.1%, 8.3% and 7.2%, respectively, compared to controls. Correspondingly, the following two-week treatment with 4g/d of plant sterols resulted in 6.5%, 10.4%, 5.5% and 3.7% difference compared to controls, being most pronounced for LDL (0.33 mmol/L). The treatments did not affect lipophilic (pro)vitamin levels.

CONCLUSION

Rye bread enriched with 2-4g/d of nonesterified plant sterols beneficially modifies cardiovascular lipid risk factors in normocholesterolemic subjects compared to controls.

Genetic variation at the NPC1L1 gene locus, plasma lipoproteins, and heart disease risk in the elderly

Niemann-Pick C1-like 1 protein (NPC1L1) plays a critical role in intestinal cholesterol absorption. Our objective was to examine whether five variants (-133A>G, -18A>C, L272L, V1296V, and U3_28650A>G) at the NPC1L1 gene have effects on lipid levels, prevalence, and incidence of coronary heart disease (CHD) and lipid-lowering response to pravastatin. We studied 5,804 elderly participants from the PROSPER study, who were randomized to prava-statin 40 mg/day or placebo and were followed on average for 3.2 years. In the adjusted gender-pooled analyses, homozygous carriers of the minor alleles at four NPC1L1 sites (-18A>C, L272L, V1296V, and U3_28650A>G, minor allele frequencies 0.15-0.33) had 2-8% higher LDL-cholesterol (LDL-C) levels at baseline than homozygous carriers of the common alleles (P < 0.05). Homozygotes for the rare alleles also had a significant increase in the risk of CHD events on trial (range of hazard ratios 1.50-1.67; P < 0.02), regardless of the treatment regimen. The -133 A>G polymorphism and not other variants was associated with 6 month LDL-C lowering (P = 0.02). Our data indicate that variation in the NPC1L1 gene is associated with plasma total and LDL-C levels and CHD risk.

Phytosterols: physiologic and metabolic aspects related to cholesterol-lowering properties

The aim of this review is to give a general contemporary overview of the physiologic effects of phytosterols and their role in cholesterol uptake in the intestinal tract. The mechanism of phytosterols action is based on its ability to reduce cholesterol absorption. Doses of 0.8 to 4.0 g/d of phytosterols were used to reduce low-density lipoprotein cholesterol concentrations by 10% to 15%, although most of the studies described used 2 g/d of phytosterol to achieve a reduction of 10% in low-density lipoprotein cholesterol concentrations. Although some studies point to the possibility that elevated plasma phytosterol concentrations could contribute to the development of premature coronary artery diseases, extensive safety evaluation studies have been conducted for these compounds, and they have been considered safe.

A natural history of botanical therapeutics

Plants have been used as a source of medicine throughout history and continue to serve as the basis for many pharmaceuticals used today. Although the modern pharmaceutical industry was born from botanical medicine, synthetic approaches to drug discovery have become standard. However, this modern approach has led to a decline in new drug development in recent years and a growing market for botanical therapeutics that are currently available as dietary supplements, drugs, or botanical drugs. Most botanical therapeutics are derived from medicinal plants that have been cultivated for increased yields of bioactive components. The phytochemical composition of many plants has changed over time, with domestication of agricultural crops resulting in the enhanced content of some bioactive compounds and diminished content of others. Plants continue to serve as a valuable source of therapeutic compounds because of their vast biosynthetic capacity. A primary advantage of botanicals is their complex composition consisting of collections of related compounds having multiple activities that interact for a greater total activity.

Non-pharmacological control of plasma cholesterol levels

The importance of non-pharmacological control of plasma cholesterol levels in the population is increasing, along with the number of subjects whose plasma lipid levels are non-optimal, or frankly elevated, according to international guidelines. In this context, a panel of experts, organized and coordinated by the Nutrition Foundation of Italy, has evaluated the nutritional and lifestyle interventions to be adopted in the control of plasma cholesterol levels (and specifically of LDL cholesterol levels). This Consensus document summarizes the view of the panel on this topic, with the aim to provide an updated support to clinicians and other health professionals involved in cardiovascular prevention.

Phytosterols and anabolic agents versus designer drugs

Cholesterol is a well-known component in fats of animal origin and it also is the precursor of natural hormones. Phytosterols appear in plants and only differ slightly in structure from cholesterol. An important difference however is the low absorption in the gut of phytosterols and their saturated derivatives, the phytostanols. As a result, there is time for all kind of reactions in faecal material inside and outside of the gut. Determination of the abuse of natural hormones may be based on gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). Abuse of natural hormones changes the 13C/12C ratio of some metabolites during a relatively long time. The formation of (natural) hormones in the gut may interfere with this method. Designer drugs are mainly known from sports doping. In animal fattening, designer drugs may be used as well. Small changes in the structure of (natural) hormones may lead to a new group of substances asking for new strategies for their detection and the constatation of their abuse.

Plant stanol esters in low-fat milk products lower serum total and LDL cholesterol

BACKGROUND

Oil-based matrices enriched with plant stanol esters lower serum LDL cholesterol. The effects of low-fat milk products have been less thoroughly examined.

AIM OF THE STUDY

To evaluate the effect of three less explored low-fat milk products enriched with plant stanol esters on serum lipid concentrations in subjects with mild or moderate hypercholesterolemia.

METHODS

A meta-analysis of four unpublished sub-studies (yoghurt, yoghurt single-shot drink: Studies I and II, or milk). All the substudies were randomized, placebo-controlled, double-blind and had a parallel-group design. They were carried out in order to evaluate the effect of low-fat milk products enriched with plant stanol esters on serum lipid concentration. Each stanol-ester-enriched milk product provided 2 g of stanols per day, and in each study the intervention period was 5 weeks. A total of 199 hypercholesterolemic subjects completed the studies.

RESULTS

The pooled treatment difference in total cholesterol was -3.8% (95% CI -6.0 to -1.7, p < 0.001) when stanol was compared to placebo. In LDL cholesterol, the pooled treatment difference was -4.9% (95% CI -7.8 to -1.8, p = 0.002). There were no significant differences between the groups in pooled HDL cholesterol or triacylglycerol concentrations. The results tended to be more pronounced when we were certain that the yoghurt single-shot drink was ingested with lunch, and when the baseline LDL-cholesterol concentration was > or = 3.5 mmol/l.

CONCLUSIONS

These results imply that low-fat milk products enriched with plant stanol esters lower both total cholesterol and LDL cholesterol statistically significantly in subjects with mild or moderate hypercholesterolemia. The changes tended to relate to the baseline LDL-cholesterol concentration.

Dietary fats, fatty acids, and their effects on lipoproteins

All saturated fatty acids, with the notable exception of stearic acid (C18:0), raise low-density lipoprotein (LDL) cholesterol levels. A few less ubiquitous fatty acids also have LDL cholesterol effects. Trans-monounsaturated fatty acids, at equivalent doses of saturated fatty acids, raise LDL cholesterol. Polyunsaturated fatty acids, at three times the dose of saturated fatty acids, lower LDL cholesterol. Higher intakes of most fatty acids raise high-density lipoprotein (HDL) cholesterol, with the notable exception of trans-monounsaturated fatty acids, which lower HDL cholesterol to the same extent as carbohydrate when either is substituted for other dietary fatty acids. Conjugated linoleic acids containing both cis and trans bonds and cis-monounsaturated fatty acids neither raise nor lower cholesterol concentrations of lipoproteins. The omega-3 fatty acids from fish lower triglyceride levels. Although dietary composition remains an important, modifiable predictor of dyslipidemia, overconsumption of any form of dietary energy may replace overconsumption of saturated fat as the primary factor that increases lipid and lipoprotein levels.

Identification of campesterol fromChrysanthemum coronarium L. and its antiangiogenic activities

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

Plasma levels of plant sterols and the risk of coronary artery disease: the prospective EPIC-Norfolk Population Study

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