Effect of Bile Salts on the Interfacial Dilational Rheology of Lecithin in the Lipid Digestion Process.

The effects of bile salts on the emulsifier adsorption layer play a crucial role in lipid digestion. The current study selected sodium cholate (NaCh) and lecithin as model compounds for bile salts and food emulsifiers, respectively. The interface dilational rheological and emulsification properties of NaCh and lecithin were carried out. The results showed that the NaCh molecules could quickly diffuse from the bulk to interface, which broke the tightly-arranged interfacial layer of lecithin and enhanced the viscoelasticity of interfacial film. As a result, the interfacial adsorption layer, which was originally dominated by the slow relaxation processes within the interface, was transformed into one controlled by the fast molecular diffusion exchange. This accelerated the exchange of materials between the bulk and interface, thereby creating suitable conditions for the interfacial adsorption of lipases, which promoted the digestion process. These results provided a mechanism for the promotion of lipid digestion by bile salts from the perspective of interfacial viscoelasticity and relaxation processes. A deeper understanding of the interfacial behavior of bile salts with emulsifiers would provide a basis for the rational design of interfacial layer for modulating lipid digestion.

Process optimization in ginseng fermentation by Monascus ruber and study on bile acid-binding ability of fermentation products in vitro.

Ginseng (Panax ginseng C. A. Meyer) is a famous Traditional Chinese Medicine, which is widely used to treat cardiovascular disease. Monascus ruber (M. ruber) is a fungus used in food and medicine fermentation, and lovastatin, its metabolite, is used extensively in the treatment of dyslipidemia. In this study, ginseng has been fermented by M. ruber, and the response surface methodology (RSM) was applied to optimize fermentation parameters to obtain optimal fermentation system, with further exploring to lipid-lowering activity of P. ginseng C. A. Meyer-M. ruber fermentation products (PM). The concentration of ginseng, temperature, and rotating speed were set as variables and the lovastatin yield was optimized by a Box-Behnken design (BBD) analyzed by RSM. The binding capacity of PM for sodium taurocholate and sodium cholate was assayed by UV spectrophotometry. The highest content of lovastatin production (85.53 µg g-1) was obtained at a ginseng concentration of 1.96%, temperature of 30.11 °C, and a rotating speed of 160.47 rpm. PM exhibited bile acid binding capacity, which was stronger than unfermented ginseng. The RSM can be used to optimize the fermentation system to obtain the best fermentation process. In addition, the fermentation of ginseng by M. ruber can enhance the lipid-lowering effect.

Sodium Cholate Bile Acid-Stabilized Ferumoxytol-Doxorubicin-Lipiodol Emulsion for Transcatheter Arterial Chemoembolization of Hepatocellular Carcinoma.

PURPOSE: To develop bile acid-stabilized multimodal magnetic resonance (MR) imaging and computed tomography (CT)-visible doxorubicin eluting lipiodol emulsion for transarterial chemoembolization of hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Ferumoxytol, a US Food and Drug Administration-approved iron oxide nanoparticle visible under MR imaging was electrostatically complexed with doxorubicin (DOX). An amphiphilic bile acid, sodium cholate (SC), was used to form a stable dispersion of ferumoxytol-DOX complex in lipiodol emulsion. Properties of the fabricated emulsion were characterized in various component ratios. Release kinetics of DOX were evaluated for the chemoembolization applications. Finally, in vivo multimodal MR imaging/CT imaging properties and potential therapeutic effects upon intra-arterial (IA) infusion bile acid-stabilized ferumoxytol-DOX-lipiodol emulsion were evaluated in orthotopic McA-Rh7777 HCC rat models. RESULTS: DOX complexed with ferumoxytol through electrostatic interaction. Amphiphilic SC bile acid at the interface between the aqueous ferumoxytol-DOX complexes and lipiodol enabled a sustained DOX release (17.2 ± 1.6% at 24 hours) at an optimized component ratio. In McA Rh7777 rat HCC model, IA-infused emulsion showed a significant contrast around tumor in both T2-weighted MR imaging and CT images (P = .044). Hematoxylin and eosin and Prussian blue staining confirmed the local deposition of IA-infused SC bile acid-stabilized emulsion in the tumor. The deposited emulsion induced significant increases in TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) stain-positive cancer cell apoptosis compared to those in a group treated with the nonstabilized emulsion. CONCLUSIONS: SC bile acid-stabilized ferumoxytol-DOX-lipiodol emulsion demonstrated sustained drug release and multimodal MR imaging/CT imaging capabilities. The new lipiodol-based formulation may enhance the therapeutic efficacy of chemoembolization in HCC.

Polyethylenimine and sodium cholate-modified ethosomes complex as multidrug carriers for the treatment of melanoma through transdermal delivery.

Aim: Multidrug resistance is the main reason for the failure of chemotherapy during the treatment of the tumor. To overcome multidrug resistance, this study attempts to develop a novel transdermal drug-delivery system (TDDS) loading cytotoxic drug and chemosensitizer. Materials & methods: The polyethylenimine-modified ethosomes (Eth-PEI) and sodium cholate-modified ethosomes (Eth-SC) were firstly fabricated, and then a novel TDDS based on the carriers complex of Eth-PEI/Eth-SC was prepared by electrostatic interaction and evaluated both in vitro and in vivo. Results: The Eth-PEI/Eth-SC showed the excellent antitumor effect on treating melanoma, using doxorubicin and curcumin as the cytotoxic drug and chemosensitizer, respectively. Conclusion: The as-prepared TDDS composed of Eth-PEI/Eth-SC loading multidrug is an effective means for treating melanoma.

Synergistic interaction between exogenous and endogenous emulsifiers and its impact on in vitro digestion of lipid in crowded medium.

Control of lipid digestibility by various food components has received great attention in recent decades. However, there is limited literature on investigating the synergistic effect of exogenous emulsifiers and endogenous sodium cholate (SC) on lipid digestion in a simulated physiological crowded medium. In this work, the synergistic interaction of Tween80 and SC according to the regular solution theory, and the hydrolysis of lipid emulsions containing tricaprylin, glyceryltrioleate or soybean oil in crowding medium was studied. The results show that emulsions stabilized by a combination of Tween80 and SC showed higher digestion rate and transformation than those with Tween80 or SC. The digestion rate could be increased by polyethylene glycols (PEGn) with varying crowding degree. The denaturation temperature of the lipase was increased in macromolecular crowded medium. This work allows for better understanding of the interaction between the amphiphiles and the macromolecular crowding effect on lipase digestion in the physiological environment.

Coffee parchment as a new dietary fiber ingredient: Functional and physiological characterization.

Coffee parchment was evaluated as a potential dietary fiber ingredient. For this purpose, dietary fiber was extracted by enzymatic and non-enzymatic methods and its physicochemical and in vitro hypoglycemic and hypolipidemic properties were investigated. Results revealed that coffee parchment (flakes and flour) was a good source of insoluble dietary fiber (IDF), mainly composed by xylans (35%), lignin (32%), and cellulose (12%). From results, the IDF extraction seemed not to be required the use of enzymes. Coffee parchment did not stand out by its content of phenolic compounds and antioxidant capacity, but milling process improved them. Due to its physical structure, coffee parchment flakes exhibited high oil holding capacity (3.8 mg L-1), gelation capacity (8%) besides hydration properties, including water holding (3.4 mg L-1), absorption (3.0 mg L-1) and swelling (14 mg L-1) capacities. Its flour and water-insoluble residue showed lower capacities. Nevertheless, these coffee parchment samples presented effective in vitro hypoglycemic properties, showing high glucose adsorption capacity (50-200 mmol L-1), and capacity to decrease its diffusion (13%), and to inhibit α-amylase (52%) that led to lower starch digestibility (until 46%); and also, outstanding in vitro hypolipidemic properties, as inhibition of pancreatic lipase (43%) and binding of cholesterol and sodium cholate (16.6 and 35.3 mg g-1, respectively). These results provide valuable information for the potential use of coffee parchment as new food DF ingredient.

Structural, antioxidant and adsorption properties of dietary fiber from foxtail millet (Setaria italica) bran.

BACKGROUND: Foxtail millet (Setaria italica) bran is a by-product of millet processing, rich in dietary fiber (DF) and has great application value. A comparative study was conducted to explore the differences in structural and functional properties among millet bran DF, soluble dietary fiber (SDF) and insoluble dietary fiber (IDF). RESULTS: There was a significant difference in the content of monosaccharides between SDF and IDF, in which xylose, arabinose and glucose were the main compositions. The results of scanning electron microscopy showed that DF and IDF had different forms of network structure, and SDF presented a sign of mutual adhesion. The total phenolic and flavonoid contents were 0.54 and 0.08 g kg-1 in SDF. Antioxidant activity of SDF was higher than that of IDF based on the evaluation of free radical scavenging and iron reducing capacity in vitro. Meanwhile, the glucose dialysis retardation index of IDF and SDF was 12.59% and 9.26% at 30 min, respectively. And, there was no significant difference in the adsorption capacity of glucose among different samples (P > 0.05). Furthermore, SDF had strong α-amylase inhibition (17.92% inhibition rate) and sodium cholate adsorption capacities; the adsorption amount was 16.76 g kg-1 in 2.00 g L-1 sodium cholate solution. CONCLUSION: Foxtail millet bran DF, especially SDF, has good functional properties and would be a suitable ingredient for health-beneficial food production. However, the relevant verification trials in vivo need to be carried out in the next steps. © 2019 Society of Chemical Industry.

Simultaneous separation and determination of praeruptorin A, B and C by micellar electrokinetic chromatography using sodium dodecyl sulphate and sodium cholate as mixed micelles.

INTRODUCTION: Praeruptorin A, B and C are major bioactive constituents in Peucedani Radix. They display anti-inflammatory effect, anti-hypertension effect, antiplatelet aggregation, potential anti-cancer activities and so on. They are worthy of investigation as potentially novel and versatile drugs. OBJECTIVE: To develop a method using micellar electrokinetic chromatography (MEKC) for the application in simultaneously separation and determination of praeruptorin A, B and C from Peucedani Radix and its medicinal preparations. METHODS: Method optimisation was carried out by investigating influences of significant factors on the separation. The method was subjected to validation. The determination of praeruptorin A, B and C in Peucedani Radix and its drug formulations was accomplished by the developed method. RESULTS: The optimal separation condition was 20 mM borate buffer containing 40 mM sodium cholate (SC), 22 mM sodium dodecyl sulphate (SDS) and 25% (v/v) acetonitrile (pH 10.00); 15 kV of voltage; 25°C of temperature; detection at 224 nm. Under this condition, three analytes were baseline separated within 16 min. A good linearity was obtained with correlation coefficients from 0.9988 to 0.9995. The limits of detection (LODs) and limits of quantitation (LOQs) ranged from 0.50 to 0.80 µg/mL and from 1.50 to 2.50 µg/mL, respectively. The recoveries ranged between 95.3% and 103.4%. CONCLUSION: The proposed method has been successfully applied to the simultaneous determination of praeruptorin A, B and C in Peucedani Radix and its pharmaceutical preparations. Additionally, it could be a potential alternative to the quality control of Peucedani Radix.

Self dispersing mixed micelles forming systems for enhanced dissolution and intestinal permeability of hydrochlorothiazide.

Mixed micelles provide promising strategy for enhancing dissolution and permeability of drugs. However, their fluid nature limited the stability of the loaded drug and hindered the development of stable oral dosage form. Accordingly, the objective was to develop solid self dispersing mixed micelle forming systems (MMFS) for enhanced dissolution and intestinal permeability of hydrochlorothiazide. Pseudoternary phase diagrams were constructed using sodium cholate, lecithin with either poloxamer 407 or PEG 4000 to determine the composition of MMFS. Both polymer free and poloxamer or PEG containing MMFS were prepared as homogenous matrices or as solid self dispersing powder. The later was developed by adsorption of MMFS on avicel-aerosil mixture. Differential scanning calorimetry provided an evidence for existence of hydrochlorothiazide as molecular dispersion in the MMFS. Dispersing polymer free, PEG 4000 or poloxamer based MMFS in aqueous medium produced micelles having size values of 119, 52.6 and 28nm, respectively. The zeta potential values were -61.8, -59.5 and -19.5mV for the same systems, respectively. Preparation of solid self dispersing MMFS enhanced the dissolution rate of hydrochlorothiazide. The intestinal absorption of hydrochlorothiazide from its aqueous solution and polymer incorporating mixed micellar systems was monitored using in situ rabbit intestinal perfusion technique. The permeability results showed a clear trend for enhanced membrane transport of the drug after being incorporated into poloxamer containing mixed micellar system. The study thus introduced a versatile easily formulated solid self dispersing system with high potential for solving the dissolution and permeability problems of class IV drugs.

Enhancing vitamin E bioaccessibility: factors impacting solubilization and hydrolysis of α-tocopherol acetate encapsulated in emulsion-based delivery systems.

Oil-soluble vitamins are often encapsulated within emulsion-based delivery systems to facilitate their incorporation into aqueous-based products. We have examined the influence of carrier oil type and simulated small intestinal fluid (SSIF) composition on the bioaccessibility of emulsified vitamin E using a gastrointestinal model. Oil-in-water emulsions containing vitamin E acetate were prepared using bile salts as emulsifier, and either long chain triacylglycerols (glyceryl trioleate, LCT) or medium chain triacylglycerols (glyceryl trioctanoate, MCT) as carrier oils. The addition of calcium (CaCl2) to the SSIF increased the extent of lipid digestion in LCT-emulsions, but had little impact in MCT-emulsions. The bioaccessibility of vitamin E increased in the presence of calcium and phospholipids (DOPC) in LCT-emulsions, but decreased in MCT-emulsions. The highest bioaccessibility (≈66%) was achieved for LCT-emulsions when the SSIF contained both calcium and phospholipids. The conversion of α-tocopherol acetate to α-tocopherol after in vitro digestion was considerably higher for LCT-emulsions when calcium ions were present in the SSIF, but was not strongly affected by SSIF composition for MCT-emulsions. In general, this research provides important information about the factors influencing the bioaccessibility of emulsified vitamin E, which could be used to design more effective emulsion-based delivery systems for increasing the oral bioavailability of this important bioactive component.

Solid lipid nanoparticles as effective reservoir systems for long-term preservation of multidose formulations.

Cosmetic multidose preparations, as well as pharmaceutical ones, are at risk of contamination by microorganisms, due to their high water content. Besides the risk of contamination during manufacturing, multidose cosmetic preparations may be contaminated by consumers during their use. In this paper, the results of the utilization of nanoparticles as reservoir systems of parabens, the most used class of preservatives, were reported. Two different systems, solid lipid nanoparticles (SLN) made of pure precirol and nanostructured lipid carriers (NLC) made of precirol and almond oil, containing three parabens as single molecules or as a mixture, were prepared and tested. All the systems were characterized for size, polydispersion index, zeta potential and encapsulation efficiency. Release experiments, carried out in steady state and sink conditions, allowed to evidence that both SLN and NLC were able to act as reservoir systems. The antimicrobial activity of the systems was tested against Candida albicans ATCC 10231 with repeat insult tests. The results of the release experiments and the antimicrobial tests showed very low water concentration of parabens still maintaining their antimicrobial activity.

Nanoberries for topical delivery of antioxidants.

With the aim of improving the antioxidant activity of polyphenols from blueberries (Vaccinium myrtillus) on skin targets after topical application, ethanolic extracts from three blueberry varieties (named Millenia, O'Neal, and Blue Crisp) were loaded into ultradeformable liposomes. These nanocarriers are known to be capable of penetrating through the stratum corneum reaching its deeper layers and the viable epidermis. On the other hand, blueberries contain large amounts of polyphenols, whose antioxidant properties as tissue protectors against processes mediated by reactive oxygen species have been extensively proved. Blueberries are usually consumed as edible products, but their antioxidant compounds are poorly absorbed. The antioxidant properties of the extracts were screened before and after being loaded into ultradeformable liposomes made of soy phosphatidylcholine and sodium cholate, of nearly 100 nm in size at 0.223 extract/lipid w/w. The ethanolic extract-loaded ultradeformable liposomes (nanoberries) from Millenia variety retained an 85% of the antioxidant capacity of the free extract and showed low cytotoxicity on HaCaT cells (less than 20%) at active concentration against free radicals.

Improved in vitro and in vivo collagen biosynthesis by asiaticoside-loaded ultradeformable vesicles.

The potentiality of ultradeformable vesicles as a possible topical delivery system for asiaticoside, a natural compound obtained from Centella asiatica was evaluated, because this compound exhibits collagen biosynthesis promoting activity. Ultradeformable vesicles were prepared by the extrusion technique; these vesicles were composed of Phospholipon 100 and different molar fractions of sodium cholate as the edge activator. The physicochemical properties of the ultradeformable vesicles were investigated through differential scanning calorimetry and light scattering techniques. The potential cyctotoxicity and biological activity of asiaticoside-loaded ultradeformable vesicles were evaluated on primary human dermal fibroblast cells by determining the extracellular lactic dehydrogenase activity, the cellular viability and the biosynthetic production of collagen. In vitro permeation experiments through human stratum corneum and epidermis membranes were also carried out. Ultradeformable vesicles having sodium cholate molar fraction of 0.2 proved to be the most suitable topical carriers for asiaticoside. A sodium cholate content of >0.2 was observed to be cytotoxic probably due to its co-existence with other lipid aggregates, an example being mixed micelles. Asiaticoside-loaded ultradeformable vesicles with a sodium cholate molar fraction of 0.2 elicited the greatest degree of collagen biosynthesis in human fibroblasts. Ultradeformable vesicles provided the greatest in vitro skin permeation of asiaticoside showing a 10-fold increase with respect to the free drug solution and favoured an increase in in vivo collagen biosynthesis. Ultradeformable vesicles are therefore suitable carriers for the pharmaceutical and cosmetic application of the natural agent asiaticoside.

Membranolytic activity of bile salts: influence of biological membrane properties and composition.

The two main steps of the membranolytic activity of detergents: 1) the partitioning of detergent molecules in the membrane and 2) the solubilisation of the membrane are systematically investigated. The interactions of two bile salt molecules, sodium cholate (NaC) and sodium deoxycholate (NaDC) with biological phospholipid model membranes are considered. The membranolytic activity is analysed as a function of the hydrophobicity of the bile salt, ionic strength, temperature, membrane phase properties, membrane surface charge and composition of the acyl chains of the lipids. The results are derived from calorimetric measurements (ITC, isothermal titration calorimetry). A thermodynamic model is described, taking into consideration electrostatic interactions, which is used for the calculation of the partition coefficient as well as to derive the complete thermodynamic parameters describing the interaction of detergents with biological membranes (change in enthalpy, change in free energy, change in entropy etc). The solubilisation properties are described in a so-called vesicle-to-micelle phase transition diagram. The obtained results are supplemented and confirmed by data obtained from other biophysical techniques (DSC differential scanning calorimetry, DLS dynamic light scattering, SANS small angle neutron scattering).

[Preparation and in vitro and in vivo evaluations of topically applied capsaicin transfersomes].

AIM: To prepare capsaicin transfersomes and evaluate them in vitro and in vivo. METHODS: Capsaicin transfersomes were prepared by high shear dispersing machine and evaluated by entrapment efficiency, release rate, in vitro skin permeation and distribution in different tissues in vivo. RESULTS: Capsaicin transfersomes were composed of single unilamellar vesicles with an average diameter of 150.6 nm. Capsaicin entrapment efficiency increased distinctly with increasing of concentration of lecithin and entrapment efficiency is 96.7% while concentration of lecithin to 8%. Cumulative release amount of capsaicin is in direct proportion to the ethanol concentration in the receptor medium. In vitro capsaicin cumulative penetration amount showed higher levels in transfersomes than cream and suspension in rat abdominal skin. Abdominal skin cumulative penetration amount in vitro of capsaicin transfersomes in mouse was significantly higher than that from rat and men. In the same way, abdominal skin epidermal membrane cumulative penetration amount in vitro of capsaicin transfersomes was significantly higher than that from derma and full skin in human abdominal skin. The capsaicin tissue distribution of capsaicin injection by multiple celiac injections in rats is different: bone > plasma > skin > muscle. There is a similar result by multiple thigh topical application of capsaicin transfersomes: bone > skin > plasma > muscle. CONCLUSION: Entrapment efficiency of capsaicin transfersomes reached the criterion of China Pharmacopoeia (> 80%) and capsaicin skin penetration can be increased by capsaicin transfersomes. It should be noted that the diverse characters and levels of skin may probably affect the permeating capability of capsaicin. Capsaicin tissue distribution in bone and muscle is similar and is different in plasma and skin by multiple injections and topical skin apply.

[Preparation of tanshinone transfersome and its deformability].

OBJECTIVE: To prepare tanshinone transfersome (TTs) and evaluate its deformability. METHODS: The transfersomes were prepared by film dispersion method followed by sonication, and their physical properties, morphology, content, entrapment efficiency, particle size, polydispersity, and Zeta potential were investigated. The stability and deformability of TTs were studied. Liposomes with different molar ratios of cholate and lecithin were compared for their permeability under external pressure. RESULTS: The prepared TF were spherical vesicles with content of 1.0192+/-0.075 mg/ml, entrapment efficiency of (62.3+/-0.08)%, particle size of 110 nm, polydispersity of 0.19 and Zate potential of -15.0 mV. The TTs remained stable during light-proof preservation for 3 months at 4 degrees C, and sodium cholate contributed to the flexibility of the lecithin vesicles. CONCLUSION: TTs prepared by film dispersion method has good entrapment efficiency and stability. The vesicles possess high deformability in relation to the molar ratio of sodium cholate to lecithin and the external pressure.

Non-aqueous capillary electrophoresis for separation and simultaneous determination of fraxin, esculin and esculetin in Cortex fraxini and its medicinal preparations.

A non-aqueous capillary electrophoresis method has been developed for the separation and simultaneous determination of fraxin, esculin and esculetin in Cortex fraxini and its preparation for the first time. Optimum separation of the analytes was obtained on a 47 cm x 75 microm i.d. fused-silica capillary using a non-aqueous buffer system of 60 mM sodium cholate, 20 mM ammonium acetate, 20% acetonitrile and 3% acetic acid at 20 kV and 292 K, respectively. The relative standard deviations (RSDs) of the migration times and the peak heights of the three analytes were in the range of 0.23-0.28 and 2.12-2.60%, respectively. Detection limits of fraxin, esculin and esculetin were 0.1557, 0.4073 and 0.5382 microg/mL, respectively. In the tested concentration range, good linear relationships (correlation coefficients 0.9995 for fraxin, 0.9999 for esculin and 0.9992 for esculetin) between peak heights and concentrations of the analytes were observed. This method has been successfully applied to simultaneous determination of the three bioactive components with the recoveries from 90.2 to 109.2% in the five samples.