Enhancing vitamin D3 bioaccessibility: Unveiling hydrophobic interactions in soybean protein isolate and vitamin D3 binding via an infant in vitro digestion model.

In the domain of infant nutrition, optimizing the absorption of crucial nutrients such as vitamin D3 (VD3) is paramount. This study harnessed dynamic-high-pressure microfluidization (DHPM) on soybean protein isolate (SPI) to engineer SPI-VD3 nanoparticles for fortifying yogurt. Characterized by notable binding affinity (Ka = 0.166 × 105 L·mol-1) at 80 MPa and significant surface hydrophobicity (H0 = 3494), these nanoparticles demonstrated promising attributes through molecular simulations. During simulated infant digestion, the 80 MPa DHPM-treated nanoparticles showcased an impressive 74.4% VD3 bioaccessibility, delineating the pivotal roles of hydrophobicity, bioaccessibility, and micellization dynamics. Noteworthy was their traversal through the gastrointestinal tract, illuminating bile salts' crucial function in facilitating VD3 re-encapsulation, thereby mitigating crystallization and augmenting absorption. Moreover, DHPM treatment imparted enhancements in nanoparticle integrity and hydrophobic properties, consequently amplifying VD3 bioavailability. This investigation underscores the potential of SPI-VD3 nanoparticles in bolstering VD3 absorption, thereby furnishing invaluable insights for tailored infant nutrition formulations.

Luminescent Alendronic Acid-Conjugated Micellar Nanostructures for Potential Application in the Bone-Targeted Delivery of Cholecalciferol.

Vitamin D, an essential micronutrient crucial for skeletal integrity and various non-skeletal physiological functions, exhibits limited bioavailability and stability in vivo. This study is focused on the development of polyethylene glycol (PEG)-grafted phospholipid micellar nanostructures co-encapsulating vitamin D3 and conjugated with alendronic acid, aimed at active bone targeting. Furthermore, these nanostructures are rendered optically traceable in the UV-visible region of the electromagnetic spectrum via the simultaneous encapsulation of vitamin D3 with carbon dots, a newly emerging class of fluorescents, biocompatible nanoparticles characterized by their resistance to photobleaching and environmental friendliness, which hold promise for future in vitro bioimaging studies. A systematic investigation is conducted to optimize experimental parameters for the preparation of micellar nanostructures with an average hydrodynamic diameter below 200 nm, ensuring colloidal stability in physiological media while preserving the optical luminescent properties of the encapsulated carbon dots. Comprehensive chemical-physical characterization of these micellar nanostructures is performed employing optical and morphological techniques. Furthermore, their binding affinity for the principal inorganic constituent of bone tissue is assessed through a binding assay with hydroxyapatite nanoparticles, indicating significant potential for active bone-targeting. These formulated nanostructures hold promise for novel therapeutic interventions to address skeletal-related complications in cancer affected patients in the future.

Unraveling the Catalytic Mechanism of ß-Cyclodextrin in the Vitamin D Formation.

Previous experimental studies have shown that the isomerization reaction of previtamin D3 (PreD3) to vitamin D3 (VitD3) is accelerated 40-fold when it takes place within a ß-cyclodextrin dimer, in comparison to the reaction occurring in conventional isotropic solutions. In this study, we employ quantum mechanics-based molecular dynamics (MD) simulations and statistical multistructural variational transition state theory to unveil the origin of this acceleration. We find that the conformational landscape in the PreD3 isomerization is highly dependent on whether the system is encapsulated. In isotropic media, the triene moiety of the PreD3 exhibits a rich torsional flexibility. However, when encapsulated, such a flexibility is limited to a more confined conformational space. In both scenarios, our calculated rate constants are in close agreement with experimental results and allow us to identify the PreD3 flexibility restriction as the primary catalytic factor. These findings enhance our understanding of VitD3 isomerization and underscore the significance of MD and environmental factors in biochemical modeling.

Fabrication, structure, characterization and emulsion application of citrate agar.

In this study, citric acid successfully reacted with agar through the dry heat method, and citrate agar (CA) gel was used to stabilize O/W emulsions. The mechanisms of the CA structure and emulsion pH that affected emulsion stabilization were analyzed, and the application of CA gel emulsion (CAGE) was explored. Compared with native agar (NA), CA showed lower gel strength, higher transparency, and higher water contact angle. These changes indicate that a cross-linking reaction occurred, and it was demonstrated via FTIR and NMR. The emulsion properties were evaluated using particle size, ζ-potential, and the emulsification activity index. Results showed that CAGEs had a smaller particle size and lower ζ-potential than the native agar gel emulsion (NAGE). Meanwhile, confocal laser scanning microscopy confirmed that the CA gels stabilized the emulsions by forming a protective film around the oil droplets. Stability experiments revealed that CAGE (prepared with CA gel [DS = 0.145]) exhibited better stability than NAGE in the pH range of 3-11, and the rheological results further confirmed that the stability of the emulsions was influenced by the network structure and oil droplet interaction forces. Afterward, the application prospect of CAGE was evaluated by encapsulating vitamin D3 and curcumin.

Biophysical insight into the binding mechanism of epigallocatechin-3-gallate and cholecalciferol to albumin and its preventive effect against AGEs formation: An in vitro and in silico approach.

Advanced glycation end products (AGEs) are produced non-enzymatically through the process of glycation. Increased AGEs production has been linked to several diseases including polycystic ovary syndrome (PCOS). PCOS contributes to the development of secondary comorbidities, such as diabetes, cardiovascular complications, infertility, etc. Consequently, research is going on AGEs-inhibiting phytochemicals for their potential to remediate and impede the progression of hyperglycaemia associated disorders. In this study human serum albumin is used as a model protein, as albumin is predominantly present in follicular fluid. This article focusses on the interaction and antiglycating potential of (-)-Epigallocatechin-3-gallate (EGCG) and vitamin D in combination using various techniques. The formation of the HSA-EGCG and HSA-vitamin D complex was confirmed by UV and fluorescence spectroscopy. Thermodynamic analysis verified the spontaneity of reaction, and presence of hydrogen bonds and van der Waals interactions. FRET confirms high possibility of energy transfer. Cumulative antiglycation resulted in almost 60 % prevention in AGEs formation, decreased alterations at lysine and arginine, and reduced protein carbonylation. Secondary and tertiary structural changes were analysed by circular dichroism, Raman spectroscopy and ANS binding assay. Type and size of aggregates were confirmed by Rayleigh and dynamic light scattering, ThT fluorescence, SEM and SDS-PAGE. Effect on cellular redox status, DNA integrity and cytotoxicity was analysed in lymphocytes using dichlorofluorescein (DCFH-DA), DAPI and MTT assay which depicted an enhancement in antioxidant level by cumulative treatment. These findings indicate that EGCG and vitamin D binds strongly to HSA and have antiglycation ability which enhances upon synergism.

The utility of Hibiscus sabdariffa L. to prepare metal oxides NPs for clinical application on osteoporosis supported by theoretical study.

Green synthesis of metal oxides as a treatment for bone diseases is still exploring. Herein, MgO and Fe2O3 NPs were prepared from the extract of Hibiscus sabdariffa L. to study their effect on vit D3, Ca+2, and alkaline phosphatase enzyme ALP associated with osteoporosis. Computational chemistry was utilized to gain insight into the possible interactions. These oxides were characterized by X-ray diffraction, SEM, FTIR, and AFM. Results revealed that green synthesis of MgO and Fe2O3 NPs was successful with abundant. MgO NPs were in vitro applied on osteoporosis patients (n = 35) and showed a significant elevation of vit D3 and Ca+2 (0.0001 > p < 0.001) levels, compared to healthy volunteers (n = 25). Thus, Hibiscus sabdariffa L. is a good candidate to prepare MgO NPs, with a promising enhancing effect on vit D3 and Ca+2 in osteoporosis. In addition, interactions of Fe2O3 and MgO NPs with ALP were determined by molecular docking study.

Vitamin D3 Bioaccessibility from Supplements and Foods-Gastric pH Effect Using a Static In Vitro Gastrointestinal Model.

Vitamin D3 deficiency is a global phenomenon, which can be managed with supplementation and food fortification. However, vitamin D3 bioaccessibility may depend on factors such as matrix composition and interactions throughout the gastrointestinal (GI) tract. This research focused on the effect of different matrices on vitamin D3 content during digestion, as well as the effect of pH on its bioaccessibility. The INFOGEST protocol was employed to simulate digestion. Three different types of commercial supplements, two foods naturally rich in vitamin D3, and three fortified foods were investigated. High-Performance Liquid Chromatography was used to determine the initial vitamin D3 content in the supplements and foods, as well as after each digestion stage. The results indicate that the foods exhibited higher bioaccessibility indices compared to the supplements and a higher percentage retention at the end of the gastric phase. The pH study revealed a positive correlation between an increased gastric pH and the corresponding content of vitamin D3. Interestingly, exposing the matrix to a low pH during the gastric phase resulted in an increased intestinal content of D3. Vitamin D3 is more bioaccessible from foods than supplements, and its bioaccessibility is susceptible to changes in gastric pH. Fasting conditions (i.e., gastric pH = 1) enhance the vitamin's bioaccessibility.

Rational Design of Trident Aptamer Scaffold for Rapid and Accurate Monitoring of 25-Hydroxyvitamin D3 Metabolism in Living Cells.

The level of 25-hydroxyvitamin D3 [25(OH)VD3] in human blood is considered as the best indicator of vitamin D status, and its deficiency or excess can lead to various health problems. Current methods for monitoring 25(OH)VD3 metabolism in living cells have limitations in terms of sensitivity and specificity and are often expensive and time-consuming. To address these issues, an innovative trident scaffold-assisted aptasensor (TSA) system has been developed for the online quantitative monitoring of 25(OH)VD3 in complex biological environments. Through the computer-aided design, the TSA system includes an aptamer molecule recognition layer that is uniformly oriented, maximizing binding site availability, and enhancing sensitivity. The TSA system achieved the direct, highly sensitive, and selective detection of 25(OH)VD3 over a wide concentration range (17.4-12,800 nM), with a limit of detection of 17.4 nM. Moreover, we evaluated the efficacy of the system in monitoring the biotransformation of 25(OH)VD3 in human liver cancer cells (HepG2) and normal liver cells (L-02), demonstrating its potential as a platform for drug-drug interaction studies and candidate drug screening.

High-shear wet agglomeration process for enriching cornstarch with curcumin and vitamin D3 co-loaded lyophilized liposomes.

Curcumin and vitamin D3 are bioactive molecules of great importance for the food industry. However, their low stability in several processing conditions hampers their proper incorporation into powdered food formulations. This study proposes the enrichment of a common raw material (cornstarch) with curcumin and vitamin D3 by using high-shear wet agglomeration. The bioactives were initially encapsulated into liposome dispersions and then subjected to lyophilization. The resulting dried vesicles were later incorporated into cornstarch by wet agglomeration using maltodextrin as the binder solution. The phospholipid content and the amount of added liposomes were evaluated to characterize the enriched cornstarch samples. The lyophilized vesicles showed a high retention rate of 99 % for curcumin and vitamin D3, while the enriched cornstarch samples retained above 96 % (curcumin) and 98 % (vitamin D3) after 30 days of controlled storage. All in all, the presence of dried liposomes improved the flowability and delayed retrogradation phenomenon in agglomerated cornstarch. Therefore, this study introduced a novel and reliable method of incorporating hydrophobic and thermosensitive molecules into powdered food formulations by using readily available materials and a straightforward high-shear wet agglomeration process.

Novel DNA Aptamer for CYP24A1 Inhibition with Enhanced Antiproliferative Activity in Cancer Cells.

Overexpression of the vitamin D3-inactivating enzyme CYP24A1 (cytochrome P450 family 24 subfamily and hereafter referred to as CYP24) can cause chronic kidney diseases, osteoporosis, and several types of cancers. Therefore, CYP24 inhibition has been considered a potential therapeutic approach. Vitamin D3 mimetics and small molecule inhibitors have been shown to be effective, but nonspecific binding, drug resistance, and potential toxicity limit their effectiveness. We have identified a novel 70-nt DNA aptamer-based inhibitor of CYP24 by utilizing the competition-based aptamer selection strategy, taking CYP24 as the positive target protein and CYP27B1 (the enzyme catalyzing active vitamin D3 production) as the countertarget protein. One of the identified aptamers, Apt-7, showed a 5.8-fold higher binding affinity with CYP24 than the similar competitor CYP27B1. Interestingly, Apt-7 selectively inhibited CYP24 (the relative CYP24 activity decreased by 39.1 ± 3% and showed almost no inhibition of CYP27B1). Furthermore, Apt-7 showed cellular internalization in CYP24-overexpressing A549 lung adenocarcinoma cells via endocytosis and induced endogenous CYP24 inhibition-based antiproliferative activity in cancer cells. We also employed high-speed atomic force microscopy experiments and molecular docking simulations to provide a single-molecule explanation of the aptamer-based CYP24 inhibition mechanism. The novel aptamer identified in this study presents an opportunity to generate a new probe for the recognition and inhibition of CYP24 for biomedical research and could assist in the diagnosis and treatment of cancer.

Molecular and structural basis of interactions of vitamin D3 hydroxyderivatives with aryl hydrocarbon receptor (AhR): An integrated experimental and computational study.

To better understand the molecular and structural basis underlying the interaction of vitamin D3 hydroxyderivatives with AhR, molecular simulation was used to probe the binding of 1,20(OH)2D3, 1,25(OH)2D3, 20,23(OH)2D3 and 20(OH)D3 to AhR. qPCR showed that vitamin D3 derivatives stimulate expression of cyp1A1 and cyp1B1 genes that are downstream targets of AhR signaling. These secosteroids stimulated the translocation of the AhR to the nucleus, as measured by flow cytometry and western blotting. Molecular dynamics simulations were used to model the binding of vitamin D3 derivatives to AhR to examine their influence on the structure, conformation and dynamics of the AhR ligand binding domain (LBD). Binding thermodynamics, conformation, secondary structure, dynamical motion and electrostatic potential of AhR were analyzed. The molecular docking scores and binding free energy were all favorable for the binding of D3 derivatives to the AhR. These established ligands and the D3 derivatives are predicted to have different patterns of hydrogen bond formation with the AhR, and varied residue conformational fluctuations and dynamical motion for the LBD. These changes could alter the shape, size and electrostatic potential distribution of the ligand binding pocket, contributing to the different binding affinities of AhR for the natural ligands and D3 derivatives.

Surface, rheopexy, digestive stability and toxicity of olive oil emulsions stabilized by chitin nanocrystals for vitamin D3 delivery.

Pickering emulsions are of interest in medicament transport systems. The properties of emulsions are influenced by the type of oil and the surface structure of nanoparticles-stabilizers. The process of formation of o/w emulsions of olive oil stabilized by chitin nanocrystals was investigated, their stability under the influence of physical factors, rheological characteristics, acute toxicity after oral administration, stability under the conditions of a model of the gastrointestinal tract, and their potential for oral transport of vitamin D3 were analyzed. Physically stable emulsions were obtained at a stabilizer concentration of 3.6 g/l. The addition of electrolyte leads to a substantial reduction in the average size of microdroplets. The resulting emulsions have rheopexy properties and the rheopexy index increases at 37 °C. Emulsions are classified as non-toxic when taken orally, physically stable in the upper digestive system, and capable of efficiently transporting vitamin D3 with a full release in the small intestine.

Synthesis of C2-Alkoxy-Substituted 19-Nor Vitamin D3 Derivatives: Stereoselectivity and Biological Activity.

The active form of vitamin D3 (D3), 1a,25-dihydroxyvitamn D3 (1,25D3), plays a central role in calcium and bone metabolism. Many structure-activity relationship (SAR) studies of D3 have been conducted, with the aim of separating the biological activities of 1,25D3 or reducing its side effects, such as hypercalcemia, and SAR studies have shown that the hypercalcemic activity of C2-substituted derivatives and 19-nor type derivatives is significantly suppressed. In the present paper, we describe the synthesis of 19-nor type 1,25D3 derivatives with alkoxy groups at C2, by means of the Julia-Kocienski type coupling reaction between a C2 symmetrical A ring ketone and a CD ring synthon. The effect of C2 substituents on the stereoselectivity of the coupling reaction was evaluated. The biological activities of the synthesized derivatives were evaluated in an HL-60 cell-based assay. The a-methoxy-substituted C2α-7a was found to show potent cell-differentiating activity, with an ED50 value of 0.38 nM, being 26-fold more potent than 1,25D3.

Affinity-based protein profiling identifies vitamin D3 as a heat shock protein 70 antagonist that regulates hedgehog transduction in murine basal cell carcinoma.

Vitamin D3 (VD3) is a seco-steroid that inhibits the Hedgehog (Hh) signaling pathway. Initial studies suggested its anti-Hh activity results from direct inhibition of Smoothened, a seven-transmembrane cell surface receptor that is a key regulator of the Hh signaling cascade. More recently, a role for the Vitamin D Receptor in mediating inhibition of Hh-signaling by seco-steroid has been suggested. Herein, an affinity-based protein profiling study was carried out to better understand the cellular proteins that govern VD3-mediated anti-Hh activity. We synthesized a novel biotinylated VD3 analogue (8) for use as a chemical probe to explore cellular binding targets of the seco-steroidal scaffold. Through a series of pull-down experiments and follow up mass spectrum analyses, heat shock protein 70 (Hsp70) was identified as a primary binding protein of VD3. Hsp70 was validated as a binding target of VD3 through a series of biochemical and cellular assays. VD3 bound with micromolar affinity to Hsp70. In addition, both selective knockdown of Hsp70 expression and pharmacological inhibition of its activity with known Hsp70 inhibitors suppressed Hh-signaling transduction in murine basal cell carcinoma cells, suggesting that Hsp70 regulates proper Hh-signaling. Additional cellular assays suggest that VD3 and its seco-steroidal metabolites inhibit Hh-signaling through different mechanisms.

The Synthesis and Biological Evaluation of D-Ring-Modified Vitamin D Analogues.

The vitamin D3 structure consists of the A-ring, a linker originating from the B-ring, C-ring, D-ring, and side-chain moieties. Each unit has its unique role in expressing the biological activities of vitamin D3. Many efforts have been made to date to assess the possible clinical use of vitamin D. Some organic chemists focused on the D-ring structure of vitamin D and synthesized D-ring-modified vitamin D analogues, and their biological activities were studied. This review summarizes the synthetic methodologies of D-ring-modified vitamin D analogues, except for seco-D, and their preliminary biological profiles.

Sulindac and vitamin D3 synergically inhibit proliferation of MCF-7 breast cancer cell through AMPK/Akt/ß-catenin axis in vitro.

Breast cancer is associated with a high rate of recurrence, resistance therapy and mortality worldwide. We aimed at investigating the inhibitory effects of Sulindac and vitamin D3 (VD) on MCF-7 human breast cancer cells. MCF-7 cells were cultured with different concentrations of Sulindac and VD over a period of 24, 48 and 72 hours for cell viability and IC50 experiments. Hochst staining was used to evaluate apoptosis, whereas quantitative PCR (qPCR) was performed to measure mRNA levels of BCL-2 and BAX genes. Immunofluorescence staining was used to monitor intracellular ß-catenin expression. The protein levels of AKT, AMPK and P65 were measured by western blotting. The result showed that cell viability decreased in treated cells dose/time dependently (P < .05). Hochst staining showed an increase in fragmented nuclei in treated cells. The expression of BCL-2 and BAX genes decreased and increased in treated cells, respectively (P < .05). Immunofluorescence staining indicated that the expression of ß-catenin significantly reduced in treated cells. The AKT-1/p-Akt-1 and AMPK/p-AMPK ratio increased in treated cells (P < .05), but the P65/p-P65 ratio did not change significantly (P > .05). Our results indicated that the combination of Sulindac and VD has a growth-inhibiting effect on MCF-7 cells through AMPK/Akt/ß-catenin axis.

Mechanisms of absorption of vitamin D3 delivered in protein nanoparticles in the absence and presence of fat.

Novel protein-based nanovehicles offer alternatives to fat for delivery of lipophilic bioactives (nutraceuticals and drugs), yet they raise important questions regarding the bioavailability and absorption mechanism of the bioactive without fat. To provide answers, we chose vitamin D3 (VD3) as a model lipophilic-nutraceutical, re-assembled casein-micelles (rCM) as model protein-based nanovehicles, and non-fat yoghurt as a model food. We prepared three yoghurt formulations: 3% fat with VD3 dissolved in milk-fat, non-fat and 3% fat, both latter enriched with VD3 within rCM. Following in vitro digestion, VD3 retention and bioaccessibility were high (∼90% and ∼70%, respectively) in all formulations. VD3 uptake by Caco-2 cells was three-fold higher (p < 0.005) in the non-fat yoghurt enriched with VD3 in rCM compared with enriched fat-containing yoghurts. SR-BI, CD36 and NPC1L1 transporters were involved in VD3 absorption irrespective of the composition. Thus, our findings demonstrate that protein nanovehicles may improve VD3 bioavailability, without altering its absorption mechanism compared to that from fat.

Improving vitamin D3 stability to environmental and processing stresses using mixed micelles.

Deficiency of vitamin-D is prevalent globally and can lead to negative health consequences. The fat-soluble nature of vitamin-D, coupled with its sensitivity to heat, light and oxygen limits its incorporation into foods. Mixed micelles (MM) have potential to enhance bioavailability of vitamin-D. This study explores the stability of MM to food processing regimes and their ability to protect vitamin-D. Subjecting MM to a range of shearing speeds (8,000-20,500 rpm) and to high pressure processing (600 MPa, 120sec) resulted in no change in MM size (4.1-4.5 nm). MM improved the retention of vitamin-D following exposure to UV-C light, near UV/visible light, and heat treatment. MM suspensions protected vitamin-D over a four week storage period at refrigeration or freezer conditions. Overall MM show potential to protect vitamin-D from degradation encountered in food processing and storage and may be beneficial as a mechanism to fortify foods with vitamin-D.

Analytical validation of an ultraviolet-visible procedure for determining vitamin D3 in vitamin D3-loaded microparticles and toxigenetic studies for incorporation into food.

Vitamin D is a water-insoluble compound presented in two main forms (D2 and D3), susceptible to environmental conditions. Microencapsulation is an alternative to supplements and preserve vitamin D properties in foods. Entrapment efficiency (EE) is the main property to evaluate the encapsulation effectiveness and therefore it is of interest the study of analytical methods for the identification and quantification of this compound within the particle. This paper describes a low cost UV-Vis methodology validation to the identification and quantification of vitamin D3 in microparticles produced by hot homogenization. The method was validated following the International Conference on Harmonization (ICH) guidelines. To guarantee safe application in foodstuff, microparticles toxigenicity was evaluated with Allium cepa L. in vivo model, showing no cytotoxic nor genotoxic potential. High entrapment efficiency was obtained, the results also demonstrated that the concentration of vitamin D3 in microparticles can be safely accessed by the validated method.

Nanoemulsion and emulsion vitamin D3 fortified edible film based on quince seed gum.

In this research, emulsions and nanoemulsions containing two concentrations of vitamin D were added to quince seed gum film and its properties were examined. Incorporation of emulsified oil droplets to the films structure was confirmed by FTIR. It was observed that presence of emulsion and nanoemulsion in the films, increased their thickness, opacity, and hydrophobicity and interaction of the gum chains with water molecules was decreased and so, water vapor permeability, water solubility, and moisture content decreased. Due to the penetration of oil molecules to the chain, the resultant films had higher elongation at break and lower tensile strength. SEM micrographs of samples showed instability of the oil droplets within the matrix. Vitamin content during 14 days of storage showed that it was more stable at lower concentration and in the nanoemulsion compared to emulsion. So, quince seed gum films containing vitamin can be introduces as an ideal edible packaging.