Preparation and properties of phytosterols with hydroxypropyl β-cyclodextrin inclusion complexes

Chitosan-coated soybean protein isolate/lecithin nanoparticles for enhancing the stability and bioaccessibility of phytosterol

BACKGROUND

Phytosterols (PS) have various beneficial effects on human health, especially the property of reducing blood cholesterol. However, the low solubility and bioaccessibility of PS have greatly limited their application in functional food ingredients.

RESULTS

To improve the bioaccessibility and stability of PS, chitosan-coated PS nanoparticles (CS-PNP) were successfully prepared by self-assembly. The properties of CS-PNP, including size, zeta potential, encapsulation efficiency (EE) and loading amount (LA) were characterised. The optimisation of CS concentration (0.4 mg mL-1) and pH (3.5) resulted in the formation of CS-PNP with an EE of over 90% and a particle size of 187.7 nm. Due to the special properties of CS chitosan, the interaction between CS and soybean protein isolate (SPI)/lecithin (SL) led to the formation of a soluble complex. CS-PNP exhibited good stability to temperature variations but was more sensitive to salt ions. During in vitro digestion, CS efficiently maintained the stability of nanoparticles against the hydrolysis of SPI by pepsin under acidic conditions. However, these nanoparticles tended to aggregate in a neutral intestinal environment. After 3 h of in vitro digestion, the bioaccessibility of PS increased from 18.2% of free PS to 63.5% of CS-PNP.

CONCLUSION

Overall, these results highlight the potential of chitosan-coated nanoparticles as effective carriers for the oral administration of PS. This multilayer construction may serve as a promising for applications in food products as delivery vehicles for nutraceuticals. © 2024 Society of Chemical Industry.

Current and New Insights on Delivery Systems for Plant Sterols in Food

Plant sterols are minor bioactive components of food lipids, which are often used for the formulation of functional foods due to their cholesterol-lowering properties. However, they have low solubility and tend to crystallize, which may affect their biological effects, the sensory profile of the sterol-enriched food, and its consumer acceptability. Moreover, due to the unsaturated structure of sterols, they are susceptible to oxidation, so different encapsulation systems have been developed to improve their dispersibility/solubility, stability, delivery, and bioaccessibility. This chapter provides an overview of the main encapsulation systems currently used for plant sterols and their application in model and food systems, with a particular focus on their efficiency and impact on sterol bioaccessibility.

Soy proteins as vehicles for enhanced bioaccessibility and cholesterol-lowering activity of phytosterols

BACKGROUND

The formulation of phytosterol (PS)-enriched functional foods has attracted increasing interest in the recent years, owing to its potential health effects. However, the poor solubility and bioavailability greatly limit PS application in this regard. This study investigated whether soy protein isolate (SPI) could effectively perform as a nanocarrier for improving the water solubility, bioaccessibility, and cholesterol-lowering activity of PSs.

RESULTS

In this work, we fabricated SPI-PS nanocomplexes, which not only can enhance the stability and bioaccessibility of PS, but also improve the cholesterol-lowering ability of SPI. This improvement was mainly due to the formation of protein-active substance complexes, through hydrophobic interactions. The complexation with PSs resulted in formation of nanosized particles with greater sizes, lower ζ-potential, and higher surface hydrophobicity. The encapsulation efficiency, loading amount, and solubility of PS were closely related to the applied PS concentration in the mixed dispersions, and the maximal PS solubility in the aqueous phase reached about 1.63 mg mL^-1 at the highest PS concentration (2.0 mg mL^-1 ). The PS molecules in the nanocomplexes were mainly present in the amorphous form. The enhanced in vitro cholesterol-lowering activity of PS nanocomplexes relative to free PS seemed to be closely related to its higher bioaccessibility.

CONCLUSION

The findings are of relevance for the development of food-grade PS ingredients suitable for the formulations of PS-enriched functional foods. © 2022 Society of Chemical Industry.

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.

Water-Dispersible Phytosterol Nanoparticles: Preparation, Characterization, and in vitro Digestion

For improving solubility and bioaccessibility of phytosterols (PS), phytosterol nanoparticles (PNPs) were prepared by emulsification–evaporation combined high-pressure homogenization method. The organic phase was formed with the dissolved PS and soybean lecithin (SL) in anhydrous ethanol, then mixed with soy protein isolate (SPI) solution, and homogenized into nanoparticles, followed by the evaporation of ethanol. The optimum fabrication conditions were determined as PS (1%, w/v): SL of 1:4, SPI content of 0.75% (w/v), and ethanol volume of 16 ml. PNPs were characterized to have average particle size 93.35 nm, polydispersity index (PDI) 0.179, zeta potential −29.3 mV, and encapsulation efficiency (EE) 97.3%. The impact of temperature, pH, and ionic strength on the stability of fabricated PNPs was determined. After 3-h in vitro digestion, the bioaccessibility of PS in nanoparticles reached 70.8%, significantly higher than the 18.2% of raw PS. Upon freeze-drying, the particle size of PNPs increased to 199.1 nm, resulting in a bimodal distribution. The solubility of PS in water could reach up to 2.122 mg/ml, ~155 times higher than that of raw PS. Therefore, this study contributes to the development of functional PS-food ingredients.

Prospects of Marine Sterols against Pathobiology of Alzheimer's Disease: Pharmacological Insights and Technological Advances

Alzheimer's disease (AD) is a degenerative brain disorder characterized by a progressive decline in memory and cognition, mostly affecting the elderly. Numerous functional bioactives have been reported in marine organisms, and anti-Alzheimer's agents derived from marine resources have gained attention as a promising approach to treat AD pathogenesis. Marine sterols have been investigated for several health benefits, including anti-cancer, anti-obesity, anti-diabetes, anti-aging, and anti-Alzheimer's activities, owing to their anti-inflammatory and antioxidant properties. Marine sterols interact with various proteins and enzymes participating via diverse cellular systems such as apoptosis, the antioxidant defense system, immune response, and cholesterol homeostasis. Here, we briefly overview the potential of marine sterols against the pathology of AD and provide an insight into their pharmacological mechanisms. We also highlight technological advances that may lead to the potential application of marine sterols in the prevention and therapy of AD.

Preparation and characterization of soybean protein isolate/pectin-based phytosterol nanodispersions and their stability in simulated digestion

In this study, stigmasterol was nanoencapsulated in soy protein isolate -pectin-based nanodispersions. Based on the particle size and zeta-potential, the optimal pectin/SPI ratio of stigmasterol nanodispersion was determined to be 1:10. At this ratio, nanodispersions was manufactured with an average particle size of 477 ± 33 nm, an encapsulation efficiency of 89.37%, and a loading amount of 17.87%. The physical properties and morphology of the nanodispersion were investigated. Fourier transform infrared spectroscopy and differential scanning calorimetry analysis revealed that stigmasterol was loaded in nanodispersions successfully. The pectin, which was used to stable nanodispersion, could restrict the release of stigmasterol in the simulated gastric fluid. This experiment indicated that the presence of pectin can improve the stability of the nanodispersion and can be used to achieve controlled release of bioactive compounds.

Nutraceutical nanodelivery; an insight into the bioaccessibility/bioavailability of different bioactive compounds loaded within nanocarriers

Nanofoods is a current concept that is based on the application of nanotechnologies in the preparation of safe foods, with superior nutritional and sensory characteristics, and capable of providing multiple health benefits. In line with the principles of this concept, food scientists have focused on developing new types of nano biosystems that can contribute to increasing the bioavailability of bioactive compounds used in food fortification. Numerous research teams have investigated the main factors limiting oral bioavailability including: bioaccessibility, absorption and transformation of bioactive compounds and bioactive-loaded nanocarriers. The physicochemical processes involved in the factors limiting oral bioavailability have been extensively studied, such asthe release, solubility and interaction of bioactive compounds and nanocarriers during food digestion, transport mechanisms of bioactive compounds and nanoparticles through intestinal epithelial cells as well as the chemical and biochemical transformations in phase I and phase II reactions. In this comprehensive review, the physicochemical processes involved in the bioaccessibility/bioavailability of different encapsulated bioactive compounds, that play an important role in human health, will be explained including polyphenols, phytosterols, carotenoids, vitamins and minerals. In particular, the mechanisms involved in the cellular uptake of bioactive-loaded nanocarriers including transcellular transport (diffusion, endocytosis, pinocytosis, transcytosis, phagocytosis), paracellular transport (through the "tight junctions" between epithelial cells), and the active transport of bioactive compounds under the action of membrane transporters are highlighted.

Bioassay-guided identification of α-amylase inhibitors in herbal extracts

This study focuses on the health benefits of several fresh herbs that are commonly used in the Mediterranean diet. Antioxidant activity, phytosterol content and α-amylase inhibitory activity of fresh basil, lavender, oregano, rosemary, sage, and thyme are analyzed and compared. High-performance thin-layer chromatography (HPTLC) combined with effect directed analysis was used to detect and quantify biological active compounds on chromatograms. The highest antioxidant activity was measured in the extract from oregano leaf, while the highest terpenoid content was in basil leaf extract. All extracts except lavender leaf and lavender flower extracts showed α-amylase inhibition. The same compound at hR_F = 68 in basil, oregano, rosemary, sage, and thyme extracts was responsible for α-amylase inhibition. Combined with effect-directed assays and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, hyphenated HPTLC allowed a fast characterization of the active compound. ATR spectral analysis of this band tentatively identified oleanolic acid (or its derivative) to be responsible for the α-amylase inhibition.

Preparation and Characterisation of Polyphenol-HP-β-Cyclodextrin Inclusion Complex that Protects Lamb Tripe Protein against Oxidation

Grape seed extract (GSE) displays strong antioxidant activity, but its instability creates barriers to its applications. Herein, three HP-β-CD/GSE inclusion complexes with host-guest ratios of 1:0.5, 1:1, and 1:2 were successfully prepared by co-precipitation method to improve stability. Successful embedding of GSE in the HP-β-CD cavity was confirmed by fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM) analyses. The Autodock Tools 1.5.6 was used to simulate the three-dimensional supramolecular structure of the inclusion complex of 2-hydroxypropyl-β-cyclodextrin and grape seed extract (HP-β-CD/GSE) by molecular docking. The MALDI-TOF-MS technology and chemical database Pubchem, and structural database PDB were combined to reconstitute the three-dimensional structure of target protein. The binding mode of the HP-β-CD/GSE inclusion complex to target protein was studied at the molecular level, and the antioxidant ability of the resulting HP-β-CD/GSE inclusion complexes was investigated by measuring 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging. The effects of HP-β-CD/GSE on myofibrillar protein from lamb tripe were also investigated under oxidative conditions. The positions and interactions of the binding sites of HP-β-CD/GSE inclusion complexes and target protein receptors were simulated by molecular docking. The results showed that HP-β-CD/GSE inclusion complexes were successfully prepared, optimally at a molar ratio of 1:2. At low (5 μmol/g) to medium (105 μmol/g) concentrations, HP-β-CD/GSE inclusion complexes decreased the carbonyl content, hydrophobicity, and protein aggregation of myofibrillar protein from lamb tripe, and increased the sulphydryl content. Furthermore, high concentration (155 μmol/g) of HP-β-CD/GSE inclusion complexes promoted protein oxidation.

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.

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.

Low density, good flowability cyclodextrin-raffinose binary carrier for dry powder inhaler: anti-hygroscopicity and aerosolization performance enhancement

BACKGROUND

The hygroscopicity of raffinose carrier for dry powder inhaler (DPI) was the main obstacle for its further application. Hygroscopicity-induced agglomeration would cause deterioration of aerosolization performance of raffinose, undermining the delivery efficiency.

METHODS

Cyclodextrin-raffinose binary carriers (CRBCs) were produced by spray-drying so as to surmount the above issue. Physicochemical attributes and formation mechanism of CRBCs were explored in detail. The flow property of CRBCs was examined by FT4 Powder Rheometer. Hygroscopicity of CRBCs was elucidated by dynamic vapor sorption study. Aerosolization performance was evaluated by in vitro deposition profile and in vivo pharmacokinetic profile of CRBC based DPI formulations.

RESULTS

The optimal formulation of CRBC (R₄) was proven to possess anti-hygroscopicity and aerosolization performance enhancement properties. Concisely, the moisture uptake of R₄ was c.a. 5% which was far lower than spray-dried raffinose (R₀, c.a. 65%). R₄ exhibited a high fine particle fraction value of 70.56 ± 0.61% and it was 3.75-fold against R₀. The pulmonary and plasmatic bioavailability of R₄ were significantly higher than R₀ (p < 0.05).

CONCLUSION

CRBC with anti-hygroscopicity and aerosolization performance enhancement properties was a promising approach for pulmonary drug delivery, which could provide new possibilities to the application of hygroscopic carriers for DPI.

Food protein-based phytosterol nanoparticles: fabrication and characterization

Phytosterols are a group of plant sterols with well-recognized LDL-cholesterol lowering effects. The water solubility and bioaccessibility of these compounds can be greatly improved by encapsulation within food protein-based nanoparticles.

Phytosterol nanoparticles with reduced crystallinity generated using nanoporous starch aerogels

Phytosterol nanoparticles with reduced crystallinity were generated by impregnation of the phytosterols into nanoporous starch aerogels using supercritical carbon dioxide.

Fabrication of electrospun polylactic acid nanofilm incorporating cinnamon essential oil/β-cyclodextrin inclusion complex for antimicrobial packaging

A novel antimicrobial packaging material was obtained by incorporating cinnamon essential oil/β-cyclodextrin inclusion complex (CEO/β-CD-IC) into polylacticacid (PLA) nanofibers via electrospinning technique. The CEO/β-CD-IC was prepared by the co-precipitation method and SEM and FT-IR spectroscopy analysis indicated the successful formation of CEO/β-CD-IC, which improved the thermal stability of CEO. The CEO/β-CD-IC was then incorporated into PLA nanofibers by electrospinning and the resulting PLA/CEO/β-CD nanofilm showed better antimicrobial activity compared to PLA/CEO nanofilm. The minimum inhibitory concentration (MIC) of PLA/CEO/β-CD nanofilm against Escherichia coli and Staphylococcus aureus was approximately 1 mg/ml (corresponding CEO concentration 11.35 μg/ml) and minimum bactericidal concentration (MBC) was approximately 7 mg/ml (corresponding CEO concentration 79.45 μg/ml). Furthermore, compared with the casting method, the mild electrospinning process was more favorable for maintaining greater CEO in the obtained film. The PLA/CEO/β-CD nanofilm can effectively prolong the shelf life of pork, suggesting it has potential application in active food packaging.

Effect of Metals, Metalloids and Metallic Nanoparticles on Microalgae Growth and Industrial Product Biosynthesis: A Review

Microalgae are a source of numerous compounds that can be used in many branches of industry. Synthesis of such compounds in microalgal cells can be amplified under stress conditions. Exposure to various metals can be one of methods applied to induce cell stress and synthesis of target products in microalgae cultures. In this review, the potential of producing diverse biocompounds (pigments, lipids, exopolymers, peptides, phytohormones, arsenoorganics, nanoparticles) from microalgae cultures upon exposure to various metals, is evaluated. Additionally, different methods to alter microalgae response towards metals and metal stress are described. Finally, possibilities to sustain high growth rates and productivity of microalgal cultures in the presence of metals are discussed.

Efficient mechanochemical complexation of various steroid compounds with α-, β- and γ-cyclodextrin

Mechanochemical technology enables solvent-free micronized solid dispersions and efficient molecular host-guest inclusion complexes to be formed in matrices which contain cyclodextrins (CDs). This type of complexation has been studied using α-, β- and γ-cyclodextrin with the dual aims of improving overall solubility and enhancing the bioavailability of common steroid compounds, such as cholic acids and β-sitosterols or lowering cholesterol content in products of animal origin. Several parameters have been studied and optimized: CD/compound molar ratio (1:1, 1:2, 2:1 and 3:1) in function of the cavity sizes of the three different CDs, milling time (from 5 to 40 min) and rotation speed (from 100 to 300 rpm). DSC (differential scanning calorimetry) analyses have revealed that inclusion complexes were efficiently formed after 40 min milling (200 rpm) for β-CD/cholesterol and β-CD/ugrsodeoxycholic acid (encapsulation efficiency 96% and 77% respectively). Besides steroid encapsulation/vehiculation, the mechanochemical technique may pave the way for new ideas in solventless steroid extraction from vegetal matrices with CDs.