Preparation of lutein-loaded particles for improving solubility and stability by Polyvinylpyrrolidone (PVP) as an emulsion-stabilizer

Encapsulation of lutein in liposomes using supercritical carbon dioxide

Liposomes loaded with lutein were prepared utilizing supercritical carbon dioxide (SC-CO₂). The effects of pressure, depressurization rate, temperature and lutein-to-lipid ratio on particle size distribution, zeta potential, encapsulation efficiency (EE), bioactive loading, morphology, phase transition and crystallinity were investigated. Liposomes prepared by the SC-CO₂ method had a particle size of 147.6±1.9nm-195.4±2.3nm, an encapsulation efficiency of 56.7±0.7%-97.0±0.8% and a zeta potential of -54.5±1.2mV to -61.7±0.6mV. A higher pressure (200-300bar) and depressurization rate (90-200bar/min) promoted a higher encapsulation of lutein whereas the lutein-to-lipid ratio had the dominant effect on the morphology of vesicles along with size distribution and EE. X-ray diffraction data implied a substantial drop in the crystallinity of lutein upon its redistribution in the liposome membranes. Differential scanning calorimetry indicated a broadened phase transition upon the simultaneous rearrangement of lutein and phospholipid molecules into liposomal vesicles. The SC-CO₂ method resulted in particle characteristics highly associated with the ability of CO₂ to disperse phospholipids and lutein molecules. It offers a promising approach to use dense phase CO₂ to homogenize hydrophobic or amphiphilic aggregates suspended in an aqueous medium and regulate the vesicular characteristics via pressure and depressurization rate. The SC-CO₂ method has potential for scalable production of liposomal nanovesicles with desirable characteristics and free of organic solvents.

Palliative effects of lutein intervention in gamma-radiation-induced cellular damages in Swiss albino mice

Objectives:

Radiation-induced hematological, biochemical, and cytogenetic damages to the normal cells are major concerns in the field of radiotherapy. The carotenoids and their derivatives have been the source of antioxidants with wide range of medicinal applications. The objective is to evaluate the protective effects of lutein, a carotenoid, against radiation-induced cellular and tissue damages.

Methods:

Swiss albino mice were grouped into 5, 50, 250, and 500 mg/kg b.wt. of lutein treatment groups, a sham and vehicle control group. The groups were irradiated with a lethal dose of 10 Gy y'-radiation. The mortality was recorded for 30 days to optimize the protective dose against radiation. The mice were administered with the compound orally for 15 consecutive days and irradiated with a sublethal dose of 6Gy. The hematological changes in blood and antioxidant parameters were determined in liver, kidney homogenates, and hemolysate/serum. The hematological parameters were recorded using an automated cell counter. The antioxidants such as malondialdehyde (MDA), glutathione (GSH), superoxide dismutase, catalase, glutathione peroxidase and glutathione-S-transferase were spectrophotometrically determined.

Results:

The red blood cell, white blood cell count, lymphocyte count, hemoglobin, platelet levels, and hematocrit value were found to be decreased in the irradiated groups. Lutein pretreatment maintains near-normal levels of these parameters indicating resistance/recovery from the radiation-induced damages. The antioxidant levels were found to be reduced in all the irradiated groups. However, lutein pretreatment (50 mg/kg b.wt.) has increased the catalase activity of hemolysate. Lutein pretreatment has reduced the MDA levels in hemolysate, when administered at doses of 5, 250, and 500 mg/kg b.wt. in comparison to its control.

Conclusion:

The study demonstrates the radioprotective potential of lutein by maintaining the hematological and antioxidant homeostasis.

Influence of calcium-induced droplet heteroaggregation on the physicochemical properties of oppositely charged lactoferrin coated lutein droplets and whey protein isolate-coated DHA droplets

The influence of calcium-induced droplet heteroaggregation on the formation and physicochemical stability of mixed lutein and DHA emulsions was studied.

Molecular mechanism of the protective effect of monomer polyvinylpyrrolidone on antioxidants - experimental and computational studies

We previously developed a lutein-polyvinylpyrrolidone (PVP) complex with improved aqueous saturation solubility and stability, though the conjugation mechanism is still unclear. In this paper, experiments with astaxanthin-PVP complex and curcumin-PVP complex were carried out, which indicated that PVP could improve the solubility and stability of astaxanthin and curcumin. We aimed to construct a computational model capable of understanding the protective effect in complexes formed between PVP and antioxidants, through which the binding mode of PVP and antioxidants was investigated with molecular modelling in order to obtain the interactions, binding energy, binding site and surface area between PVP and antioxidants. Solubility enhancement was attributed to the H-bonds between PVP and antioxidants, and the saturation solubility was curcumin > lutein > astaxanthin. Binding energy, binding site and surface area were beneficial for the stability of complex, and the stability enhancement was lutein > astaxanthin > curcumin. The experimental results were in agreement with the computational results. Furthermore, we established a method for the exploration of a similar system with other polymer complexes. Additionally, the proposed PVP model could predict the interactions between PVP and various ligands, such as antioxidants and drugs.

Intermolecular Interactions and the Release Pattern of Electrospun Curcumin-Polyvinyl(pyrrolidone) Fiber

An electrospun fiber of polyvinyl(pyrrolidone) (PVP)-Tween 20 (T20) with curcumin as the encapsulated drug has been developed. A study of intermolecular interactions was performed using Raman spectroscopy, Fourier transform infrared (FT-IR), differential scanning calorimetry (DSC), and X-ray diffraction (XRD). The Raman and FT-IR studies showed that curcumin preferrably interacted with T20 and altered PVP chain packing, as supported by XRD and physical stability data. The hydroxyl stretching band in PVP shifted to a lower wavenumber with higher intenstity in the presence of curcumin and PVP, indicating that hydrogen bond formation is more intense in a curcumin or curcumin-T20 containing fiber. The thermal pattern of the fiber did not indicate phase separation. The conversion of curcumin into an amorphous state was confirmed by XRD analysis. An in vitro release study in phosphate buffer pH 6.8 showed that intermolecular interactions between each material influenced the drug release rate. However, low porosity was found to limit the hydrogen bond-mediated release.

Preparation of enteric-coated microcapsules of astaxanthin oleoresin by complex coacervation

Astaxanthin oleoresin (AO) has a number of beneficial physiological functions. However, its sensitivity to light, heat, oxygen and gastric fluids has limited its application. In this paper, we describe the preparation of AO enteric microcapsules by coacervation to improve its stability and enteric solubility, and evaluate their efficacy by measuring the drug loading, encapsulation efficiency, optical microscopic appearance, stability, in vitro release and bioavailability. The results obtained showed that the AO enteric microcapsules possessed a high encapsulation efficiency (85.9%), a satisfactory in vitro release profile, and the ability of the microencapsulated AO to resist the effects of light, heat and oxygen was improved by 2.2-fold, 3.1-fold and 2.4-fold, respectively, during storage. In addition, the bioavailability of AO microcapsules was approximately 1.29-fold higher than AO, which is important for pharmaceutical applications and as a functional food.

Inhibition of Photodegradation of Highly Dispersed Folic Acid Nanoparticles by the Antioxidant Effect of Transglycosylated Rutin

We developed highly dispersible and photostable nanoparticles of vitamin, folic acid (FA). FA was wet bead milled with milling and dispersing adjuvants and transglycosylated compounds such as α-glucosyl hesperidin (Hesperidin-G) and rutin (Rutin-G), which solubilized FA. The milled slurries of FA particles with transglycosylated compounds consisted of nanosized particles with a median diameter of <100 nm. The lyophilized formulations of these slurries retained their nanometer size after resuspension in water with no aggregation. The apparent solubility of FA in these formulations was 100-fold higher than that of untreated FA. The solubilizing effect of Rutin-G may affect the particle size reduction and dispersibility of FA. The photostability results showed that the strong antioxidant activity of Rutin-G substantially increased the photostability of FA solution. On the basis of these results, bead milling of FA with Rutin-G is a promising technique for developing highly dispersible, photostable nanoparticle FA formulations.

Fabrication and characterization of ferritin–chitosan–lutein shell–core nanocomposites and lutein stability and release evaluation in vitro

The nano-sized ferritin and chitosan provide a platform for fabricating shell–core system to encapsulate lutein, exhibiting improved stability and prolonged release of lutein in simulated gastrointestinal tract digestion.