Water dispersible plant sterol formulation shows improved effect on lipid profile compared to plant sterol esters

Liposomal Phytosterols as LDL-Cholesterol-Lowering Agents in Diet-Induced Hyperlipidemia

The high blood level of low-density lipoprotein cholesterol (LDL-C) is a primary risk factor for cardiovascular disease. Plant sterols, known as phytosterols (PSs), can reduce LDL-C in a range of 8-14%. The extent of LDL-C reduction depends on its formulation. Encapsulation into liposomes is one formulation strategy to enhance the efficiency of PSs. PSs (campesterol, stigmasterol, and β-sitosterol) have frequently been assessed alone or in combination for their LDL-C-lowering ability. However, one naturally abundant PS, brassicasterol, has not yet been tested for its efficacy. We have previously developed a novel liposomal formulation containing the PS mixture present naturally in canola that is composed of brassicasterol, campesterol, and β-sitosterol. In this work, the efficacy of our novel liposomal PS formulation that includes brassicasterol was assessed in a hamster model. Animals were divided into five groups: (i) liposomal PS in orange juice, (ii) liposomal PS in water, (iii) marketed PS in orange juice, (iv) control orange juice, and (v) control water. The animals were fed a high-fat, cholesterol-supplemented (0.5%) diet to induce hypercholesterolemia. The treatment was administered orally once daily for 4 weeks. Fasting blood samples were collected at baseline, week 2, and week 4. The extent of the reduction of total cholesterol, LDL-C, high-density lipoprotein cholesterol (HDL-C), and triglycerides was compared among the groups. Liposomal PSs in both orange juice and water significantly reduced LDL-C compared to their controls. Furthermore, the liposomal PS was as effective as a marketed PS-containing product in reducing LDL-C. Liposomal PSs in both orange juice and water showed similar efficacy in LDL-C reduction, highlighting that these vehicles/food matrices do not affect the efficacy of PSs. The liposomal formulation of a natural PS mixture extracted from canola oil, with brassicasterol as a major component, exhibited a significant LDL-C reduction in a hamster model.

Solubilization of free β-sitosterol in milk sphingomyelin and polar lipid vesicles as carriers: Structural characterization of the membranes and sphingosome morphology

High consumption of plant sterols reduces the risk of cardiovascular diseases in humans and provides health benefits. Increasing the amount of plant sterols in the diet is therefore necessary to reach the recommended daily dietary intake. However, food supplementation with free plant sterols is challenging because of their low solubility in fats and water. The objectives of this study were to investigate the capacity of milk-sphingomyelin (milk-SM) and milk polar lipids to solubilise β-sitosterol molecules in bilayer membranes organised as vesicles called sphingosomes. The thermal and structural properties of milk-SM containing bilayers composed of various amounts of β-sitosterol were examined by differential scanning calorimetry (DSC) and temperature-controlled X-ray diffraction (XRD), the molecular interactions were studied using the Langmuir film technique, the morphologies of sphingosomes and β-sitosterol crystals were observed by microscopy. We showed that the milk-SM bilayers devoid of β-sitosterol exhibited a gel to fluid L_α phase transition for T_m = 34.5 °C and formed facetted spherical sphingosomes below T_m. The solubilisation of β-sitosterol within milk-SM bilayers induced a liquid-ordered L_o phaseabove 25 %mol (1.7 %wt) β-sitosterol and a softening of the membranes leading to the formation of elongated sphingosomes. Attractive molecular interactions revealed a condensing effect of β-sitosterol on milk-SM Langmuir monolayers. Above 40 %mol (25.7 %wt) β-sitosterol, partitioning occured with the formation of β-sitosterol microcrystals in the aqueous phase. Similar results were obtained with the solubilization of β-sitosterol within milk polar lipid vesicles. For the first time, this study highlighted the efficient solubilization of free β-sitosterol within milk-SM based vesicles, which opens new market opportunities for the formulation of functional foods enriched in non-crystalline free plant sterols.

Efficacy of Submicron Dispersible Free Phytosterols on Non-Alcoholic Fatty Liver Disease: A Pilot Study

BACKGROUND

No pharmacological treatment is yet approved for non-alcoholic fatty liver disease (NAFLD). Plant sterols have shown healthy properties beyond lowering LDL-cholesterol, including lowering triglycerides and lipoprotein plasma levels. Despite pre-clinical data suggesting their involvement in liver fat control, no clinical study has yet been successful.

AIMS

Testing a sub-micron, free, phytosterol dispersion efficacy on NAFLD.

METHODS

A prospective, uncontrolled pilot study was carried out on 26 patients with ≥17.4% liver steatosis quantified by magnetic resonance imaging. Subjects consumed daily a sub-micron dispersion providing 2 g of phytosterols. Liver fat, plasma lipids, lipoproteins, liver enzymes, glycemia, insulinemia, phytosterols, liposoluble vitamins and C-reactive protein were assessed at baseline and after one year of treatment.

RESULTS

Liver steatosis relative change was -19%, and 27% of patients reduced liver fat by more than 30%. Statistically and clinically significant improvements in plasma triglycerides, HDL-C, VLDL and HDL particle number and C-reactive protein were obtained, despite the rise of aspartate aminotransferase, glycemia and insulinemia. Though phytosterol plasma levels were raised by >30%, no adverse effects were presented, and even vitamin D increased by 23%.

CONCLUSIONS

Our results are the first evidence in humans of the efficacy of submicron dispersible phytosterols for the treatment of liver steatosis, dyslipidemia and inflammatory status in NAFLD.

Production, Characterization, Delivery, and Cholesterol-Lowering Mechanism of Phytosterols: A Review

Phytosterols are natural plant-based bioactive compounds that can lower blood cholesterol levels and help prevent cardiovascular diseases. Consequently, they are being utilized in functional foods, supplements, and pharmaceutical products designed to improve human health. This paper summarizes different approaches to isolate, purify, and characterize phytosterols. It also discusses the hypolipidemic mechanisms of phytosterols and their impact on cholesterol transportation. Phytosterols have a low water-solubility, poor chemical stability, and limited bioavailability, which limits their utilization and efficacy in functional foods. Strategies are therefore being developed to overcome these shortcomings. Colloidal delivery systems, such as emulsions, oleogels, liposomes, and nanoparticles, have been shown to be effective at improving the water-dispersibility, stability, and bioavailability of phytosterols. These delivery systems can be used to incorporate phytosterols into a broader range of cholesterol-lowering functional foods and beverages. We also discuses several issues that need to be addressed before these phytosterol delivery systems can find widespread commercial utilization.

Assessment of Plant Sterols in the Diet of Adult Polish Population with the Use of a Newly Developed Database

Plant sterols are compounds with multiple biological functions, mainly cholesterol-reducing. There are no comprehensive databases on plant sterols, which makes it difficult to estimate their intake in the Polish population. This work attempted to use international food databases, additionally supplemented by scientific data from the literature, to create a database of plant sterols, which would cover various kinds of foods and dishes consumed in Poland. The aim was to assess the size and sources of dietary plant sterols in the adult population of Poland. The literature search was conducted using PubMed, Web of Science, Scopus, and Google Scholar to identify possible sources of published food composition data for plant sterols. The study group consisted of 5690 participants of the WOBASZ II survey. We identified 361 dietary sources of plant sterols based on the consumption of foods and dishes reported by participants. Cereals and fats provided 61% of the total plant sterols, and together with vegetables and fruits, this totaled 80%. The median intake of plant sterols in the Polish population was 255.96 mg/day, and for men and women 291.76 and 230.61 mg/day, respectively. Canola oil provided the most plant sterols at 16.92%, followed by white bread at 16.65% and soft margarine at 8.33%. The study found that plant sterol intake in Poland is comparable to other populations, and women’s diets are more dense in plant sterols. Due to the lack of literature sources on plant sterol content in some foods, future studies should expand and complete the databases on plant sterol content in foods.

Nutraceuticals: Transformation of Conventional Foods into Health Promoters/Disease Preventers and Safety Considerations

Nutraceuticals are essential food constituents that provide nutritional benefits as well as medicinal effects. The benefits of these foods are due to the presence of active compounds such as carotenoids, collagen hydrolysate, and dietary fibers. Nutraceuticals have been found to positively affect cardiovascular and immune system health and have a role in infection and cancer prevention. Nutraceuticals can be categorized into different classes based on their nature and mode of action. In this review, different classifications of nutraceuticals and their potential therapeutic activity, such as anti-cancer, antioxidant, anti-inflammatory and anti-lipid activity in disease will be reviewed. Moreover, the different mechanisms of action of these products, applications, and safety upon consumers including current trends and future prospect of nutraceuticals will be included.

Analytical Strategies to Analyze the Oxidation Products of Phytosterols, and Formulation-Based Approaches to Reduce Their Generation

Phytosterols are a class of lipid molecules present in plants that are structurally similar to cholesterol and have been widely utilized as cholesterol-lowering agents. However, the susceptibility of phytosterols to oxidation has led to concerns regarding their safety and tolerability. Phytosterol oxidation products (POPs) present in a variety of enriched and non-enriched foods can show pro-atherogenic and pro-inflammatory properties. Therefore, it is crucial to screen and analyze various phytosterol-containing products for the presence of POPs and ultimately design or modify phytosterols in such a way that prevents the generation of POPs and yet maintains their pharmacological activity. The main approaches for the analysis of POPs include the use of mass spectrometry (MS) linked to a suitable separation technique, notably gas chromatography (GC). However, liquid chromatography (LC)-MS has the potential to simplify the analysis due to the elimination of any derivatization step, usually required for GC-MS. To reduce the transformation of phytosterols to their oxidized counterparts, formulation strategies can theoretically be adopted, including the use of microemulsions, microcapsules, micelles, nanoparticles, and liposomes. In addition, co-formulation with antioxidants, such as tocopherols, may prove useful in substantially preventing POP generation. The main objectives of this review article are to evaluate the various analytical strategies that have been adopted for analyzing them. In addition, formulation approaches that can prevent the generation of these oxidation products are proposed.

Effects of Daily Consumption of an Aqueous Dispersion of Free-Phytosterols Nanoparticles on Individuals with Metabolic Syndrome: A Randomised, Double-Blind, Placebo-Controlled Clinical Trial

Metabolic syndrome (MS) affects up to 40% of the population and is associated with heart failure, stroke and diabetes. Phytosterols (PS) could help to manage one or more MS criteria. The purpose of this study was to evaluate the therapeutic effect of daily supplementation of an aqueous dispersion of 2 g of free-phytosterols nanoparticles in individuals with MS over six months of intervention, compared with placebo. This double-blind study included 202 participants with MS randomly assigned into phytosterol (n = 102) and placebo (n = 100) groups. Participants were assessed at baseline, 4, 12 and 24 weeks. General health questions, anthropometric measurements and blood parameters were analysed. At week 24, the proportion of participants with high triglycerides (≥150 mg/dL) in the phytosterol group was 15.65% lower than in the placebo group (p-value = 0.023). Similarly, half of the participants in the phytosterol group decreased their waist circumference up to 4 cm compared with 0 cm in the placebo group (p-value = 0.0001). We reported no adverse effects (diarrhoea or vitamin D reduction); nonetheless, almost 70% of participants in the phytosterol group self-reported an improvement in bowel habits. Daily intake of free-PS nanoparticles improved some MS criteria; therefore, it might be a promising adjuvant therapy for individuals with MS (NCT02969720).

Progress and perspectives in plant sterol and plant stanol research

Current evidence indicates that foods with added plant sterols or stanols can lower serum levels of low-density lipoprotein cholesterol. This review summarizes the recent findings and deliberations of 31 experts in the field who participated in a scientific meeting in Winnipeg, Canada, on the health effects of plant sterols and stanols. Participants discussed issues including, but not limited to, the health benefits of plant sterols and stanols beyond cholesterol lowering, the role of plant sterols and stanols as adjuncts to diet and drugs, and the challenges involved in measuring plant sterols and stanols in biological samples. Variations in interindividual responses to plant sterols and stanols, as well as the personalization of lipid-lowering therapies, were addressed. Finally, the clinical aspects and treatment of sitosterolemia were reviewed. Although plant sterols and stanols continue to offer an efficacious and convenient dietary approach to cholesterol management, long-term clinical trials investigating the endpoints of cardiovascular disease are still lacking.

In Vitro Bioaccessibility of Low-Crystallinity Phytosterol Nanoparticles Generated Using Nanoporous Starch Bioaerogels

Phytosterols are natural health-promoting bioactive compounds; however, phytosterols have very limited bioavailability due to their crystalline lipophilic structure. With the aim of improving bioaccessibility, low-crystallinity phytosterol nanoparticles were generated by supercritical carbon dioxide (SC-CO₂ ) impregnation of phytosterols into nanoporous starch aerogels (NSAs). The in vitro bioaccessibility of the phytosterol nanoparticles (35%) was significantly higher than that of the crude phytosterols (3%) after sequential oral, gastric, and intestinal digestion. The percentages of starch hydrolysis were not different among the various NSA preparations and reached to 64% after sequential digestion. The zeta potential of the phytosterol nanoparticles was higher compared to that of crude phytosterols in the micellar phase; indicating higher stability. The findings of this study support the use of NSA to produce nanoparticles of reduced crystallinity to improve the bioaccessibility of the lipophilic bioactive compounds. PRACTICAL APPLICATIONS: This novel process can decrease the size and crystallinity of phytosterols and thus improve phytosterols' bioavailability. It is a blueprint to apply to other water insoluble food bioactives. This novel approach may (i) improve the health benefits of water-insoluble bioactives; (ii) enable food manufacturers to add water-insoluble bioactives into low- and high-fat foods to produce health-promoting foods; and (iii) enhance the cost-benefit ratio of water insoluble bioactives.

Development and Characterization of Liposomal Formulations Containing Phytosterols Extracted from Canola Oil Deodorizer Distillate along with Tocopherols as Food Additives

Phytosterols are plant sterols recommended as adjuvant therapy for hypercholesterolemia and tocopherols are well-established anti-oxidants. However, thermo-sensitivity, lipophilicity and formulation-dependent efficacy bring challenges in the development of functional foods, enriched with phytosterols and tocopherols. To address this, we developed liposomes containing brassicasterol, campesterol and β-sitosterol obtained from canola oil deodorizer distillate, along with alpha, gamma and delta tocopherol. Three approaches; thin film hydration-homogenization, thin film hydration-ultrasonication and Mozafari method were used for formulation. Validated liquid chromatographic tandem mass spectrometry (LC-MS/MS) was utilized to determine the entrapment efficiency of bioactives. Stability studies of liposomal formulations were conducted before and after pasteurization using high temperature short time (HTST) technique for a month. Vesicle size after homogenization and ultrasonication (<200 nm) was significantly lower than by Mozafari method (>200 nm). However, zeta potential (-9 to -14 mV) was comparable which was adequate for colloidal stability. Entrapment efficiencies were greater than 89% for all the phytosterols and tocopherols formulated by all three methods. Liposomes with optimum particle size and zeta potential were incorporated in model orange juice, showing adequate stability after pasteurization (72 °C for 15 s) for a month. Liposomes containing phytosterols obtained from canola waste along with tocopherols were developed and successfully applied as a food additive using model orange juice.

Mild and Efficient Preparation of Phytosteryl Amino Acid Ester Hydrochlorides and Their Emulsifying Properties

The aim of this work was to produce a series of phytosteryl amino acid ester hydrochlorides by a two-step method, which involved esterification of phytosterols with N- tert-butoxycarbonyl (BOC) amino acid and deprotection of the BOC group. The highest yield of over 95.0% was obtained when the catalysts were the mixtures of 1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide hydrochlide, 4-dimethylaminopyridine, and triethylamine. It was found that batch charging of the reactants and catalysts was conducive to improving the yield. In addition, over 99.0% of the BOC group deprotection degree was achieved using the HCl/ethyl acetate deprotection method. All of the compounds were characterized by fourier transform infrared spectroscopy, mass spectroscopy, and nuclear magnetic resonance spectroscopy. The emulsifying properties of phytosterols and phytosteryl amino acid ester hydrochlorides were also investigated. The results showed higher emulsifying properties of phytosteryl amino acid ester hydrochlorides, which could favor its wide application in food systems.

LDL-Cholesterol Lowering of Plant Sterols and Stanols-Which Factors Influence Their Efficacy?

The LDL-cholesterol (LDL-C) lowering effect of plant sterols/stanols (PSS) is summarized in several meta-analyses showing a dose-response relationship with intakes of 1.5 to 3 g/day lowering LDL-C by 7.5% to 12%. This review summarizes evidence for the impact of various factors potentially influencing the LDL-C-lowering efficacy of PSS. PSS are efficacious in all food formats and in food supplements. Some factors related to food format, e.g., solid vs. liquid foods, seem to impact efficacy, while there is no difference between free PSS and esters. Compared to multiple daily intakes, once-a-day intake of PSS, especially in the morning with light breakfast, leads to a sub-optimal LDL-C lowering. However, intake frequency seems influenced by intake occasion, i.e., with or without a meal, and time of day. Meal intake is a critical factor for an optimal LDL-C lowering efficacy of PSS. While age has no impact, gender is suggested to influence the LDL-C lowering effect of PSS with greater reductions reported for men than women; but overall evidence is inconclusive and larger studies show no gender by treatment interaction. In conclusion, PSS are efficacious in all foods and food supplements; for optimal efficacy they should be consumed with a (main) meal and twice daily.

Effect of Phytosterols on the Crystallization Behavior of Oil-in-Water Milk Fat Emulsions

Milk has been used commercially as a carrier for phytosterols, but there is limited knowledge on the effect of added plant sterols on the properties of the system. In this study, phytosterols dispersed in milk fat at a level of 0.3 or 0.6% were homogenized with an aqueous dispersion of whey protein isolate (WPI). The particle size, morphology, ζ-potential, and stability of the emulsions were investigated. Emulsion crystallization properties were examined through the use of differential scanning calorimetry (DSC) and Synchrotron X-ray scattering at both small and wide angles. Phytosterol enrichment influenced the particle size and physical appearance of the emulsion droplets, but did not affect the stability or charge of the dispersed particles. DSC data demonstrated that, at the higher level of phytosterol addition, crystallization of milk fat was delayed, whereas, at the lower level, phytosterol enrichment induced nucleation and emulsion crystallization. These differences were attributed to the formation of separate phytosterol crystals within the emulsions at the high phytosterol concentration, as characterized by Synchrotron X-ray measurements. X-ray scattering patterns demonstrated the ability of the phytosterol to integrate within the milk fat triacylglycerol matrix, with a concomitant increase in longitudinal packing and system disorder. Understanding the consequences of adding phytosterols, on the physical and crystalline behavior of emulsions may enable the functional food industry to design more physically and chemically stable products.