Water soluble biocompatible vesicles based on polysaccharides and oligosaccharides inclusion complexes for carotenoid delivery

Anticancer Activity of Astaxanthin-Incorporated Chitosan Nanoparticles

Astaxanthin (AST)-encapsulated nanoparticles were fabricated using glycol chitosan (Chito) through electrostatic interaction (abbreviated as ChitoAST) to solve the aqueous solubility of astaxanthin and improve its biological activity. AST was dissolved in organic solvents and then mixed with chitosan solution, followed by a dialysis procedure. All formulations of ChitoAST nanoparticles showed small diameters (less than 400 nm) with monomodal distributions. Analysis with Fourier transform infrared (FT-IR) spectroscopy confirmed the specific peaks of AST and Chito. Furthermore, ChitoAST nanoparticles were formed through electrostatic interactions between Chito and AST. In addition, ChitoAST nanoparticles showed superior antioxidant activity, as good as AST itself; the half maximal radical scavenging concentrations (RC50) of AST and ChitoAST nanoparticles were 11.8 and 29.3 µg/mL, respectively. In vitro, AST and ChitoAST nanoparticles at 10 and 20 µg/mL properly inhibited the production of intracellular reactive oxygen species (ROSs), nitric oxide (NO), and inducible nitric oxide synthase (iNOS). ChitoAST nanoparticles had no significant cytotoxicity against RAW264.7 cells or B16F10 melanoma cells, whereas AST and ChitoAST nanoparticles inhibited the growth of cancer cells. Furthermore, AST itself and ChitoAST nanoparticles (20 µg/mL) efficiently inhibited the migration of cancer cells in a wound healing assay. An in vivo study using mice and a pulmonary metastasis model showed that ChitoAST nanoparticles were efficiently delivered to a lung with B16F10 cell metastasis; i.e., fluorescence intensity in the lung was significantly higher than in other organs. We suggest that ChitoAST nanoparticles are promising candidates for antioxidative and anticancer therapies of B16F10 cells.

The Endless World of Carotenoids-Structural, Chemical and Biological Aspects of Some Rare Carotenoids

Carotenoids are a large and diverse group of compounds that have been shown to have a wide range of potential health benefits. While some carotenoids have been extensively studied, many others have not received as much attention. Studying the physicochemical properties of carotenoids using electron paramagnetic resonance (EPR) and density functional theory (DFT) helped us understand their chemical structure and how they interact with other molecules in different environments. Ultimately, this can provide insights into their potential biological activity and how they might be used to promote health. In particular, some rare carotenoids, such as sioxanthin, siphonaxanthin and crocin, that are described here contain more functional groups than the conventional carotenoids, or have similar groups but with some situated outside of the rings, such as sapronaxanthin, myxol, deinoxanthin and sarcinaxanthin. By careful design or self-assembly, these rare carotenoids can form multiple H-bonds and coordination bonds in host molecules. The stability, oxidation potentials and antioxidant activity of the carotenoids can be improved in host molecules, and the photo-oxidation efficiency of the carotenoids can also be controlled. The photostability of the carotenoids can be increased if the carotenoids are embedded in a nonpolar environment when no bonds are formed. In addition, the application of nanosized supramolecular systems for carotenoid delivery can improve the stability and biological activity of rare carotenoids.

Improving the Treatment Effect of Carotenoids on Alzheimer's Disease through Various Nano-Delivery Systems

Natural bioactive compounds have recently emerged as a current strategy for Alzheimer's disease treatment. Carotenoids, including astaxanthin, lycopene, lutein, fucoxanthin, crocin and others are natural pigments and antioxidants, and can be used to treat a variety of diseases, including Alzheimer's disease. However, carotenoids, as oil-soluble substances with additional unsaturated groups, suffer from low solubility, poor stability and poor bioavailability. Therefore, the preparation of various nano-drug delivery systems from carotenoids is a current measure to achieve efficient application of carotenoids. Different carotenoid delivery systems can improve the solubility, stability, permeability and bioavailability of carotenoids to a certain extent to achieve Alzheimer's disease efficacy. This review summarizes recent data on different carotenoid nano-drug delivery systems for the treatment of Alzheimer's disease, including polymer, lipid, inorganic and hybrid nano-drug delivery systems. These drug delivery systems have been shown to have a beneficial therapeutic effect on Alzheimer's disease to a certain extent.

Extraction, purification, structure characteristics, biological activities and pharmaceutical application of Bupleuri Radix Polysaccharide: A review

Bupleuri Radix (BR), as a well-known plant medicine of relieving exterior syndrome, has a long history of usage in China. Bupleuri Radix Polysaccharide (BRP), as the main component and an important bioactive substance of BR, has a variety of pharmacological activities, including immunoregulation, antioxidant, antitumor, anti-diabetic and anti-aging, etc. In this review, the advancements on extraction, purification, structure characteristics, biological activities and pharmaceutical application of BRP from different sources (Bupleurum chinense DC., Bupleurum scorzonerifolium Willd., Bupleurum falcatum L. and Bupleurum smithii Woiff. var. Parvifolium Shan et Y. Li.) are summarized. Meanwhile, this review makes an in-depth discussion on the shortcomings of the research on BRP, and new valuable insights for the future researches of BRP are proposed.

Biopolymer from Water Kefir as a Potential Clean-Label Ingredient for Health Applications: Evaluation of New Properties

The present work aimed to characterize the exopolysaccharide obtained from water kefir grains (EPSwk), a symbiotic association of probiotic microorganisms. New findings of the technological, mechanical, and biological properties of the sample were studied. The EPSwk polymer presented an Mw of 6.35 × 105 Da. The biopolymer also showed microcrystalline structure and characteristic thermal stability with maximum thermal degradation at 250 °C. The analysis of the monosaccharides of the EPSwk by gas chromatography demonstrated that the material is composed of glucose units (98 mol%). Additionally, EPSwk exhibited excellent emulsifying properties, film-forming ability, a low photodegradation rate (3.8%), and good mucoadhesive properties (adhesion Fmax of 1.065 N). EPSwk presented cytocompatibility and antibacterial activity against Escherichia coli and Staphylococcus aureus. The results of this study expand the potential application of the exopolysaccharide from water kefir as a potential clean-label raw material for pharmaceutical, biomedical, and cosmetic applications.

Cyclodextrins in the antiviral therapy

The main antiviral drug-cyclodextrin interactions, changes in physicochemical and physiological properties of the most commonly used virucides are summarized. The potential complexation of antiviral molecules against the SARS-Cov2 also pointed out the lack of detailed information in designing effective and general medicines against viral infections. The principal problem of the current molecules is the 3D structures of the currently active compounds. Improving the solubility or bioavailability of antiviral molecules is possible, however, there is no universal solution, and the complexation experiments dominantly use the already approved cyclodextrin derivatives. This review discusses the basic properties of the different cyclodextrin derivatives, their potential in antiviral formulations, and the prevention and treatment of viral infections. The biologically active new cyclodextrin derivatives are also discussed.

Stability of Fucoxanthin in Pasteurized Skim and Whole Goat Milk

Obesity has become a worldwide problem giving rise to several health issues. Fucoxanthin, a marine carotenoid with anti-obesity activity, has potential application as a biofunctional ingredient in human food. The objective of this study was to evaluate the thermal stability of fucoxanthin at pasteurization temperature and, subsequently, its storage stability in goat whole milk (WM) and skim milk (SM) at refrigeration temperature for four weeks. Additionally, the effect of supplementation of fucoxanthin on the composition of milk, pH, acidity, color, and lipid oxidation of WM and SM was evaluated during the four week storage period. Fresh goat WM and SM were supplemented with fucoxanthin at a concentration of 10.67 µg/mL (2.56 mg/240 mL of milk, one serving), pasteurized at 64 °C for 30 min and stored at 4 °C for four weeks. The quantification of fucoxanthin in WM and SM was performed every week using a HPLC method. Moreover, the effect of supplementation of fucoxanthin on the composition of WM and SM was evaluated by a LactiCheck milk analyzer, and the color was evaluated by reflectance using a HunterLab colorimeter. Lipid oxidation, as the 2-thiobarbituric acid-reactive substances (TBARS) at A532, was determined using a Spectramax Plus spectrophotometer during storage. Data were analyzed by a split-plot design using PROC MIXED of SAS. The recovery yields of fucoxanthin from the pasteurized WM and SM were 96.17 ± 1.5 % and 96.89 ± 1.5 %, respectively. Both milks exhibited high recovery yields of fucoxanthin. Fucoxanthin was stable in goat WM and SM during storage at 4 °C for four weeks. The addition of fucoxanthin, at the concentration reported to have an anti-obesity effect in humans, to pasteurized WM and SM did not affect the composition or the physicochemical properties of milks but influenced the color, especially increasing the yellowness in the samples. These results revealed that goat milk can be used as a suitable matrix for the supplementation of fucoxanthin as a biofunctional ingredient in human foods.

Inositol hexanicotinate self-micelle solid dispersion is an efficient drug delivery system in the mouse model of non-alcoholic fatty liver disease

Inositol hexanicotinate (IHN) self-micelle solid dispersion (SD) with glycyrrhizic acid (GA) and arabic gum (AG) was prepared by mechanical ball milling process to improve the solubility, stability of amorphous state, and bioavailability of IHN, which enhanced the treatment of IHN on hyperlipidemia and nonalcoholic fatty liver disease (NAFLD). The physicochemical properties of IHN/GA/AG SDs in solid state were characterized by differential scanning calorimetry, X-ray diffraction studies, and scanning electron microscopy. The characteristics of the sample solutions were analyzed by reverse-phase HPLC, particle characterization, critical micelle concentration, and transmission electron microscopy. Further pharmacokinetic study of this SD formulation in rats showed a significant 3.3-fold increase in bioavailability compared to pure IHN. Moreover, biomarkers in serum and liver of NAFLD mice were significantly ameliorated after oral administration of IHN/GA/AG SDs for 15 days. Altogether, these results establish the mechanochemically prepared IHN/GA/AG SDs as an efficacious formulation for the treatment of hyperlipidemia and NAFLD.

Integrated Structural Studies for Elucidating Carotenoid-Protein Interactions

Carotenoids are ancient pigment molecules that, when associated with proteins, have a tremendous range of functional properties. Unlike most protein prosthetic groups, there are no recognizable primary structure motifs that predict carotenoid binding, hence the structural details of their amino acid interactions in proteins must be worked out empirically. Here we describe our recent efforts to combine complementary biophysical methods to elucidate the precise details of protein-carotenoid interactions in the Orange Carotenoid Protein and its evolutionary antecedents, the Helical Carotenoid Proteins (HCPs), CTD-like carotenoid proteins (CCPs).

Recent Advances on Nanoparticle Based Strategies for Improving Carotenoid Stability and Biological Activity

Carotenoids are natural pigments widely used in food industries due to their health-promoting properties. However, the presence of long-chain conjugated double bonds are responsible for chemical instability, poor water solubility, low bioavailability and high susceptibility to oxidation. The application of a nanoencapsulation technique has thus become a vital means to enhance stability of carotenoids under physiological conditions due to their small particle size, high aqueous solubility and improved bioavailability. This review intends to overview the advances in preparation, characterization, biocompatibility and application of nanocarotenoids reported in research/review papers published in peer-reviewed journals over the last five years. More specifically, nanocarotenoids were prepared from both carotenoid extracts and standards by employing various preparation techniques to yield different nanostructures including nanoemulsions, nanoliposomes, polymeric/biopolymeric nanoparticles, solid lipid nanoparticles, nanostructured lipid nanoparticles, supercritical fluid-based nanoparticles and metal/metal oxide nanoparticles. Stability studies involved evaluation of physical stability and/or chemical stability under different storage conditions and heating temperatures for varied lengths of time, while the release behavior and bioaccessibility were determined by various in vitro digestion and absorption models as well as bioavailability through elucidating pharmacokinetics in an animal model. Moreover, application of nanocarotenoids for various biological applications including antioxidant, anticancer, antibacterial, antiaging, cosmetics, diabetic wound healing and hepatic steatosis were summarized.

Carotenoids: Importance in Daily Life-Insight Gained from EPR and ENDOR

Carotenoids are indispensable molecules for life. They are present everywhere in plants, algae, bacteria whom they protect against free radicals and oxidative stress. Through the consumption of fruits and vegetables and some carotenoid-containing fish, they are introduced into the human body and, similarly, protect it. There are numerous health benefits associated with the consumption of carotenoids. Carotenoids are antioxidants but at the same time they are prone to oxidation themselves. Electron loss from the carotenoid forms a radical cation. Furthermore, proton loss from a radical cation forms a neutral radical. In this mini-review, we discuss carotenoid radicals studied in our groups by various physicochemical methods, namely the radical cations formed by electron transfer and neutral radicals formed by proton loss from the radical cations. They contain many similar hyperfine couplings due to interactions between the electron spin and numerous protons in the carotenoid. Different EPR and ENDOR methods in combination with DFT calculations have been used to distinguish the two independent carotenoid radical species. DFT predicted larger coupling constants for the neutral radical compared to the radical cation. Previously, INDO calculations miss assigned the large couplings to the radical cation. EPR and ENDOR have aided in elucidating the physisorb, electron and proton transfer processes that occur when carotenoids are adsorbed on solid artificial matrices, and predicted similar reactions in aqueous solution or in plants. After years of study of the physicochemical properties of carotenoid radicals, the different published results start to merge together for a better understanding of carotenoid radical species and their implication in biological systems. Up until 2008, the radical chemistry in artificial systems was elucidated but the correlation between quenching ability and neutral radical formation was an inspiration to look for these radical species in vivo. In addition, the EPR spin-trapping technique has been applied to study inclusion complexes of carotenoids with different delivery systems.

Recent Developments in Solid Lipid Microparticles for Food Ingredients Delivery

Health food has become a prominent force in the market place, influencing many food industries to focus on numerous bioactive compounds to reap benefits from its properties. Use of these compounds in food matrices has several limitations. Most of the food bio-additives are sensitive compounds that may quickly decompose in both food and within the gastrointestinal tract. Since most of these bioactives are highly or partially lipophilic molecules, they possess very low water solubility and insufficient dispersibility, leading to poor bioavailability. Thus, various methods of microencapsulation of large number of food bioactives have been studied. For encapsulation of hydrophobic compounds several lipid carriers and lipid platforms have been studied, including emulsions, microemulsions, micelles, liposomes, and lipid nano- and microparticles. Solid lipid particles (SLP) are a promising delivery system, can both deliver bioactive compounds, reduce their degradation, and permit slow and sustained release. Solid lipid particles have important advantages compared to other polymer carriers in light of their simple production technology, including scale up ability, higher loading capacity, extremely high biocompatibility, and usually low cost. This delivery system provides improved stability, solubility in various matrixes, bioavailability, and targeting properties. This article reviews recent studies on microencapsulation of selected bioactive food ingredients in solid lipid-based carriers from a point of view of production methods, characteristics of obtained particles, loading capability, stability, and release profile.

The colorful world of carotenoids: a profound insight on therapeutics and recent trends in nano delivery systems

The therapeutic effects of carotenoids as dietary supplements to control or even treat some specific diseases including diabetic retinopathy, cardiovascular diseases, bacterial infections, as well as breast, prostate, and skin cancer are discussed in this review and also thoughts on future research for their widespread use are emphasized. From the stability standpoint, carotenoids have low bioavailability and bioaccessibility owing to their poor water solubility, deterioration in the presence of environmental stresses such as oxygen, light, and high heat as well as rapid degradation during digestion. Nanoencapsulation technologies as wall or encapsulation materials have been increasingly used for improving food product functionality. Nanoencapsulation is a versatile process employed for the protection, entrapment, and the delivery of food bioactive products including carotenoids from diverse environmental conditions for extended shelf lives and for providing controlled release. Therefore, we present here, recent (mostly during the last five years) nanoencapsulation methods of carotenoids with various nanocarriers. To us, this review can be considered as the first highlighting not only the potential therapeutic effects of carotenoids on various diseases but also their most effective nanodelivery systems.HighlightsBioactive compounds are of deep interest to improve food properties.Carotenoids (such as β-carotene and xanthophylls) play indispensable roles in maintaining human health and well-being.A substantial research effort has been carried out on developing beneficial nanodelivery systems for various carotenoids.Nanoencapsulation of carotenoids can enhance their functional properties.Stable nanoencapsulated carotenoids could be utilized in food products.

Preparation and characterization of an injectable dexamethasone-cyclodextrin complexes-loaded gellan gum hydrogel for cartilage tissue engineering

In this study, 6-(6-aminohexyl) amino-6-deoxy-β-cyclodextrin-gellan gum complex hydrogel (HCD-GG) was developed to enhance the affinity of anti-inflammatory drug dexamethasone (Dx), improve chondrogenesis, and decrease the inflammatory response. The modified chemical structure was confirmed by NMR and FTIR. Mechanical and physicochemical properties were characterized by performing viscosity study, compression test, injection force test, swelling kinetic, weight loss, and morphological study. The release profile of the drug-loaded hydrogels was analyzed to confirm the affinity of the hydrophobic drugs and the matrix and characterize cumulative release. In vitro test was carried out with MTT assay, live/dead staining, glycosaminoglycan (GAGs) content, double-stranded DNA (dsDNA) content, morphological analysis, histology, and gene expression. In vivo experiment was conducted by implanting the samples under a subcutaneous area of SPD rat and cartilage defected rabbit model. The results displayed successfully synthesized HCD-GG. The gelation temperature of the modified hydrogels was decreased while the mechanical property was improved when the drug was loaded in the modified hydrogel. Swelling and degradation kinetics resulted in a higher level compared to the pristine GG but was a sufficient level to support drugs and cells. The affinity and release rate of the drug was higher in the HCD-GG group which shows an improved drug delivery system of the GG-based material. The microenvironment provided a suitable environment for cells to grow. Also, chondrogenesis was affected by the existence of Dx and microenvironment, resulting in higher expression levels of cartilage-related genes while the expression of the inflammation mediators decreased when the Dx was loaded. In vivo study showed an improved anti-inflammatory response in the drug-loaded hydrogel. Furthermore, the cartilage defected rabbit model showed an enhanced regenerative effect when the Dx@HCD-GG was implanted. These results suggest that HCD-GG and Dx@HCD-GG have the potential for cartilage regeneration along with multiple applications in tissue engineering and regenerative medicine.

Soluble Cyanobacterial Carotenoprotein as a Robust Antioxidant Nanocarrier and Delivery Module

To counteract oxidative stress, antioxidants including carotenoids are highly promising, yet their exploitation is drastically limited by the poor bioavailability and fast photodestruction, whereas current delivery systems are far from being efficient. Here we demonstrate that the recently discovered nanometer-sized water-soluble carotenoprotein from Anabaena sp. PCC 7120 (termed AnaCTDH) transiently interacts with liposomes to efficiently extract carotenoids via carotenoid-mediated homodimerization, yielding violet–purple protein samples. We characterize the spectroscopic properties of the obtained pigment–protein complexes and the thermodynamics of liposome–protein carotenoid transfer and demonstrate the delivery of carotenoid echinenone from AnaCTDH into liposomes with an efficiency of up to 70 ± 3%. Most importantly, we show efficient carotenoid delivery to membranes of mammalian cells, which provides protection from reactive oxygen species (ROS). Incubation of neuroblastoma cell line Tet21N in the presence of 1 μM AnaCTDH binding echinenone decreased antimycin A ROS production by 25% (p < 0.05). The described carotenoprotein may be considered as part of modular systems for the targeted antioxidant delivery.

Effect of Glycyrrhizic Acid and Arabinogalactan on the Membrane Potential of Rat Thymocytes Studied by Potential-Sensitive Fluorescent Probe

The effect of the natural saponin glycyrrhizic acid (GA) and polysaccharide arabinogalactan (AG) on the transmembrane potential of rat thymocytes was investigated using the potential-sensitive fluorescent probe 4-(p-dimethylaminostyryl)-1-methylpyridinium (DSM). Incubation of cells with GA in micellar form resulted in a decrease of the amplitude of observed fluorescence kinetics that points out to a decrease of the transmembrane potential. The proposed mechanism is an increase of membrane ion permeability (passive ion transport) of the plasma cell membrane due to GA incorporation. The incorporation of GA molecules into the cell membrane is extremely sensitive to the degree of GA dissociation. The neutral form of glycyrrhizic acid enters the lipid bilayer in contrast to the deprotonated anionic form. The incubation of rat thymocytes with anionic form of GA, namely with its disodium salt, has no effect on the fluorescence kinetics. The possible reasons of this phenomenon are discussed in the light of the nuclear magnetic resonance (NMR) and molecular dynamics (MD) data. The treatment of thymocytes with AG affects only the initial rate of the probe incorporation. The proposed mechanism is that AG covers the surface of the cell membrane and forms a barrier for the probe. Additionally, our experiments demonstrated that both polysaccharide AG and GA in the neutral form (but not Na₂GA) effectively capture the cationic probe in an aqueous solution and then deliver it to the cell membrane.

Antioxidant Activity in Supramolecular Carotenoid Complexes Favored by Nonpolar Environment and Disfavored by Hydrogen Bonding

Carotenoids are well-known antioxidants. They have the ability to quench singlet oxygen and scavenge toxic free radicals preventing or reducing damage to living cells. We have found that carotenoids exhibit scavenging ability towards free radicals that increases nearly exponentially with increasing the carotenoid oxidation potential. With the oxidation potential being an important parameter in predicting antioxidant activity, we focus here on the different factors affecting it. This paper examines how the chain length and donor/acceptor substituents of carotenoids affect their oxidation potentials but, most importantly, presents the recent progress on the effect of polarity of the environment and orientation of the carotenoids on the oxidation potential in supramolecular complexes. The oxidation potential of a carotenoid in a nonpolar environment was found to be higher than in a polar environment. Moreover, in order to increase the photostability of the carotenoids in supramolecular complexes, a nonpolar environment is desired and the formation of hydrogen bonds should be avoided.

Improving the cancer prevention/treatment role of carotenoids through various nano-delivery systems

One of the emerging and recent strategies to combat cancer is application of natural bioactive compounds and phytochemicals. Carotenoids including lycopene, β-carotene, astaxanthin, crocin, β-cryptoxanthin, and lutein, are the main group of plant pigments which play important roles in the prevention and healing process of different diseases including cancer. The pharmacological use of carotenoid compounds is frequently limited by their low bioavailability and solubility as they are mainly lipophilic compounds. The present study focuses on the current data on formulation of different carotenoid nanodelivery systems for cancer therapy and a brief overview of the obtained results. Encapsulation of carotenoids within different nanocarriers is a remarkable approach and innovative strategy for the improvement of health-promoting features and particularly, cancer prevention/treatment roles of these compounds through enhancing their solubility, cellular uptake, membrane permeation, bioaccessibility, and stability. There is various nanocarrier for loading carotenoids including polymeric/biopolymeric, lipid-based, inorganic, and hybrid nanocarriers. Almost in all relevant studies, these nano delivery systems have shown promising results in improving the efficiency of carotenoids in cancer therapy. [Formula: see text].

Arabinogalactan and glycyrrhizin based nanopesticides as novel delivery systems for plant protection

During the past decade, nanotechnologies opened a new era in delivery of plant protection products through the development of nanosized controlled release systems, such as polymer nanoparticles, micelles, and so on using a wide variety of materials. To increase the pesticides penetration into the grain under the presowing seed treatment, a new approach based on non-covalent associate preparation with natural polysaccharides and oligosaccharides as delivery systems (DSs) was applied. Earlier, this approach was tested on antidote 1,8-naphthalic anhydride (NA). Enhancement of the NA solubility and penetration into the barley and wheat seeds had been demonstrated. In the present study, these DSs were used to prepare nanocomposites of pesticides (tebuconazole, imidacloprid, imazalil, prochloraz). The composite formation of the pesticides with poly- and oligosaccharides was proved by NMR relaxation method. Enhancement of the pesticides solubility and improvement of its penetration into the seeds of corn and rapeseeds has been detected. The strongest enhancement of penetration ability was observed for arabinogalactan nanocomposites: 5-folds for tebuconazole and imidacloprid, and more than 10-folds for imazalil and prochloraz. Our data show that the effect of polysaccharides and oligosaccharides on the nanopesticide penetration might be associated with the solubility enhancement, affinity of DSs to the surface of grains, and the modification of cell membranes by poly- and oligosaccharides.

Supramolecular Carotenoid Complexes of Enhanced Solubility and Stability-The Way of Bioavailability Improvement

Carotenoids are natural dyes and antioxidants widely used in food processing and in therapeutic formulations. However, their practical application is restricted by their high sensitivity to external factors such as heat, light, oxygen, metal ions and processing conditions, as well as by extremely low water solubility. Various approaches have been developed to overcome these problems. In particular, it was demonstrated that application of supramolecular complexes of “host-guest” type with water-soluble nanoparticles allows minimizing the abovementioned disadvantages. From this point of view, nanoencapsulation of carotenoids is an effective strategy to improve their stability during storage and food processing. Also, nanoencapsulation enhances bioavailability of carotenoids via modulating their release kinetics from the delivery system, influencing the solubility and absorption. In the present paper, we present the state of the art of carotenoid nanoencapsulation and summarize the data obtained during last five years on preparation, analysis and reactivity of carotenoids encapsulated into various nanoparticles. The possible mechanisms of carotenoids bioavailability enhancement by multifunctional delivery systems are also discussed.

Recent progress regarding kaempferol for the treatment of various diseases

Kaempferol, also known as kaempferol-3 or kaempferide, is a flavonoid compound that naturally occurs in tea, as well as numerous common vegetables and fruits, including beans, broccoli, cabbage, gooseberries, grapes, kale, strawberries, tomatoes, citrus fruits, brussel sprouts, apples and grapefruit. The present review mainly summarizes the application of kaempferol in treating diseases and the underlying mechanisms that are currently being studied. Due to its anti-inflammatory properties, it may be used to treat numerous acute and chronic inflammation-induced diseases, including intervertebral disc degeneration and colitis, as well as post-menopausal bone loss and acute lung injury. In addition, it has beneficial effects against cancer, liver injury, obesity and diabetes, inhibits vascular endothelial inflammation, protects the cranial nerve and heart function, and may be used for treating fibroproliferative disorders, including hypertrophic scar.

Development and evaluation of lutein-loaded alginate microspheres with improved stability and antioxidant

BACKGROUND

Lutein has been of great interest to the food processing and pharmaconutrient industries owing to its beneficial effects on human health. However, lutein is very sensitive to heat, light, pH and oxidative conditions, which limits its application in food systems. The present study aimed to prepare lutein-alginate microspheres by a calcium chloride gelation method with the purpose of improving the stability and antioxidant abilities of lutein.

RESULTS

The loading capacity of lutein in the microspheres was approximately 5.3% (w/w) and the entrapment efficiency was about 63%. The loaded microspheres were nearly spherical with an average size of 150 μm. They exhibited a crimped surface by scanning electron microscopy. The lutein was in amorphous state by X-ray powder diffraction. Analysis by Fourier transform infrared spectroscopy and molecular docking revealed an intermolecular hydrogen bond interaction between lutein and sodium alginate. In vitro release experiments showed that the microspheres presented slower release at acidic conditions than at neutral intestinal conditions. The 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity of the microencapsulated lutein was higher than that of free lutein. The stability of lutein in the microspheres was improved significantly when compared with that of free lutein at various temperatures.

CONCLUSION

The present work successfully developed well-protected lutein-alginate microspheres. This indicates that it is feasible to use microspheres loaded with lutein as antioxidant functional ingredients in food products. © 2019 Society of Chemical Industry.

Insights into Micellization of Octenylsuccinated Oat β-Glucan and Uptake and Controlled Release of β-Carotene by the Resultant Micelles

The core-shell structured micelles from octenylsuccinated oat β-glucan (OSβG) are able to solubilize β-carotene (βC). This study reveals molecular interactions governing the formation, stabilization, and βC uptake of OSβG micelles (OSβG-Ms) by means such as water contact angle, ¹H nuclear magnetic resonance, dynamic light scattering, and confocal laser scanning microscopy. The results indicated that the micellization of OSβG molecules is triggered by hydrophobic interactions between octenylsuccinate (OSA) moieties, while OSβG-Ms are stabilized via both hydrophobic interactions and hydrogen bonds. For their uptake of βC, βC molecules are first adsorbed onto OSβG-Ms by interacting with OSA moieties scattered on micelle surface. By further interacting with OSA moieties located in micelle shell, βC molecules travel across the shell and finally are trapped in the hydrophobic core. In simulated gastrointestinal fluids, βC is controlled released from OSβG-Ms as an integrated consequence of its diffusion as well as the swelling and erosion of OSβG-Ms. As a result, this study first uncovered the mechanism underlying the uptake of βC by OSβG-Ms, which will certainly facilitate the effective loading of hydrophobic ingredients by OSβG-Ms.

Glycyrrhizin-Assisted Transport of Praziquantel Anthelmintic Drug through the Lipid Membrane: An Experiment and MD Simulation

Praziquantel (PZQ) is one of the most widespread anthelmintic drugs. However, the frequent insufficient application of PZQ after oral administration is associated with its low solubility, penetration rate, and bioavailability. In the present study, the permeation of PZQ through a 1,2-dioleoyl- sn-glycero-3-phosphocholine (DOPC) membrane was investigated to probe glycyrrhizin-assisted transport. Glycyrrhizin (or glycyrrhizic acid, GA), a natural saponin, shows the ability to enhance the therapeutic activity of various drugs when it is used as a drug delivery system. However, the molecular mechanism of this effect is still under debate. In the present study, the transport rate was measured experimentally by a parallel artificial membrane permeation assay (PAMPA) and molecular dynamics (MD) simulation with DOPC lipid bilayers. The formation of the noncovalent supramolecular complex of PZQ with disodium salt of GA (Na2GA) in an aqueous solution was proved by the NMR relaxation technique. PAMPA experiments show a strong increase in the amount of the penetrating praziquantel molecules in comparison with a saturated aqueous solution of pure drug used as a control. MD simulation of PZQ penetration through the bilayer demonstrates an increase in permeability into the membrane in the presence of a glycyrrhizin molecule. A decrease in the free energy barrier in the middle of the lipid bilayer was obtained, associated with the hydrogen bond between PZQ and GA. Also, GA reduces the local bilayer surface resistance to penetration of PZQ by rearranging the surface lipid headgroups. This study clarifies the mechanism of increasing the drug's bioavailability in the presence of glycyrrhizin.

One-step mechanochemical preparation and prominent antitumor activity of SN-38 self-micelle solid dispersion

Purpose

The purpose of this study was to overcome the clinical defects of 7-ethyl-10-hydroxycamptothecin (SN-38) and explore its characteristics and antitumor effects.

Materials and methods

An amorphous solid dispersion of SN-38 with disodium glycyrrhizin (Na₂GA) was prepared by mechanical ball milling (Na₂GA/SN-38-BM). Moreover, an untreated mixture of Na₂GA and SN-38 (Na₂GA/SN-38-UM), a pure drug SN-38, was prepared for comparison with Na₂GA/SN-38-BM. The samples were characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), dynamic light scattering, and transmission electron microscopy. Then, further in vitro and in vivo studies were performed including cell uptake, cytotoxicity, antitumor efficacy, tissue distribution, and histopathological evaluation (H&E staining).

Results

SN-38 loaded in Na₂GA was self-formed as nano-micelles in water. The particle size of nano-micelle was 69.41 nm and ζ-potential was -42.01 mV. XRD and SEM analyses showed that the ball milling transformed SN-38 crystals into amorphous form and that solubility increased by 189 times. Compared with SN-38 and Na₂GA/SN-38-UM, Na₂GA/SN-38-BM has a stronger cytotoxicity to tumor cells and exhibited a significant inhibition of tumor growth. Then, pharmacokinetic studies showed that the bioavailability of Na₂GA/SN-38-BM was about four times that of SN-38 suspension.

Conclusion

Na₂GA/SN-38-BM (69 nm, -42 mV) nanoparticles which had excellent phar-macokinetic and distribution properties can dramatically enhance the anticancer efficacy of SN-38 in vitro and in vivo, suggesting a promising formulation for efficient anticancer therapy.

Atorvastatin calcium inclusion complexation with polysaccharide arabinogalactan and saponin disodium glycyrrhizate for increasing of solubility and bioavailability

The aim of the present investigation was to enhance the solubility and dissolution of atorvastatin calcium (ATV), a poorly water-soluble drug with larch polysaccharide arabinogalactan (AG) and disodium glycyrrhizate (Na₂GA) as carriers of drug delivery systems for improving its bioavailability. The interactions of ATV with AG or Na₂GA were investigated by DSC, XRD, SEM, and NMR techniques. The molecular weights of supramolecular systems-inclusion complexes and micelles-which are the hosts for ATV molecules were measured. On the other hand, the rapid storage assay (+ 40 °C for 3 months) showed that the chemical stability of ATV/AG and ATV/Na₂GA complexes had been enhanced compared with pure ATV. In vitro drug release showed a significant increase in ATV's dissolution rate after formation of a complex with Na₂GA or AG. Pharmacokinetic tests in vivo on laboratory animals showed a significant increase in ATV's bioavailability after its introduction as a complex with Na₂GA or AG. Moreover, ATV/AG and ATV/Na₂GA complexes showed a more prominent decrease of total cholesterol (TC) level compared to net ATV. Therefore, the novel mechanochemically synthesized complexes of ATV with AG or Na₂GA as drug delivery systems might be potential and promising candidates for hypercholesterolemia treatment and deserved further researches.

Preparation of curcumin self-micelle solid dispersion with enhanced bioavailability and cytotoxic activity by mechanochemistry

An amorphous solid dispersion (SD) of curcumin (Cur) with disodium glycyrrhizin (Na2GA) was prepared by mechanical ball milling. Curcumin loaded micelles were self-formed by Na2GA when SD dissolved in water. The physical properties of Cur SD in solid state were characterized by differential scanning calorimetry, X-ray diffraction studies, and scanning electron microscope. The characteristics of the sample solutions were analyzed by reverse phase HPLC, UV-visible spectroscopy, 1H NMR spectroscopy, gel permeation LC, and transmission electron microscopy. In vitro cytotoxic tests demonstrated that Cur SD induced higher cytotoxicity against glioblastoma U-87 MG cells than free Cur. Besides, an improvement of membrane permeability of Cur SD was confirmed by parallel artificial membrane permeability assay. Further pharmacokinetic study of this SD formulation in rat showed a significant ∼19-fold increase of bioavailability as comparing to free Cur. Thus, Cur SD provide a more potent and efficacious formulation for Cur oral delivery.

Nanoliposomes as Vehicles for Astaxanthin: Characterization, In Vitro Release Evaluation and Structure

Astaxanthin was encapsulated in nanoliposomes by a film dispersion-ultrasonic technique using soybean phosphatidyl choline. The astaxanthin-loaded nanoliposomes displayed advantages in the aspects of high encapsulation efficiency and less particle size with a remarkably homodisperse size distribution. Based on X-ray diffraction and differential scanning calorimetry the analysis, it has been demonstrated that there could be interactions of astaxanthin with the lipid bilayer, resulting in the forming of astaxanthin-loaded nanoliposomes. The thermal gravimetric analysis revealed that the thermal stability of astaxanthin after encapsulation in nanoliposomes was remarkably enhanced as compared to astaxanthin alone. Furthermore, encapsulation could greatly enhance the water dispersibility of astaxanthin. This study also confirmed that encapsulation of astaxanthin in nanoliposomes could be an effective way to supply astaxanthin continuously in the body. The effects of astaxanthin incorporation on structural changes of the liposomal membrane were investigated through steady-state fluorescence measurements. This study revealed that the incorporation of astaxanthin into the lipid bilayer decreased membrane fluidity, but increased micropolarity in the membrane within a certain range of astaxanthin concentrations. Additionally, it indicated that the encapsulation of astaxanthin in the lipid bilayer could be applied to modulate the structural properties of membranes.

Supramolecular Complex of Ibuprofen with Larch Polysaccharide Arabinogalactan: Studies on Bioavailability and Pharmacokinetics

BACKGROUND AND OBJECTIVES

In the present work, pharmacological and pharmacokinetic properties of the supramolecular complex of non-steroid anti-inflammatory drug ibuprofen (IBU) with natural polysaccharide arabinogalactan (AG) were studied. The main goals of such complexation were the increase of ibuprofen's bioavailability and decrease its effective dose after oral administration.

METHODS

The complex with mass ratio as IBU:AG 1:10 was obtained by mechanochemical synthesis and characterized by water solubility, electron microscopy, differential scanning calorimetry, X-ray powder diffraction analysis and ¹H-nuclear magnetic resonance spectroscopy. Different animal models of pain and inflammation was used to investigate IBU:AG biological effects. Plasma concentration of IBU and its pharmacokinetic parameters were evaluated after oral introduction.

RESULTS

It was found that ibuprofen's effective analgesic and anti-inflammatory dose decreased twofold after its introduction as a complex with AG. The reason of this difference is due to the increase of ibuprofen concentration in rats' plasma: C _max of IBU at doses of 20 and 40 mg/kg was found as 0.088 and 0.132 μg/ml, whereas C _max of IBU in the complex form was 0.103 and 0.160 μg/ml, respectively.

CONCLUSIONS

Thus, we have shown that complexation of the IBU with AG results in its bioavailability increase, reduction of the effective dose and should decrease toxic side effects.

Markers of Hypoxia and Oxidative Stress in Aging Volunteers Ingesting Lycosomal Formulation of Dark Chocolate Containing Astaxanthin

OBJECTIVE

To determine if ingestion of lycosome-formulated dark chocolate (DC) containing astaxanthin (ASTX) improves bioavailability of ASTX and affects markers of hypoxia and oxidative stress in aging individuals.

DESIGN

Randomized, blinded, four-arm, prospective study.

SETTINGS

Lycotec Ltd, Cambridge, United Kingdom and Institute of Cardiology, Saratov, Russian Federation.

PARTICIPANTS

32 healthy individuals aged 60-70 years with confirmed signs of oxidative stress (increased serum levels of oxidized LDL and malonic dialdehyde) randomized into four study groups (8 volunteers each).

INTERVENTION

Volunteers of first group were given orally 10 gr of dark chocolate (DC). Individuals from the second group received 7 mg of astaxanthin (ASTX). Third group of volunteers was supplemented with 10 gr of DC and 7 mg of ASTX ingested simultaneously as two separate formulations. Last group of the individuals was given 10 gr of a lycosomal formulation of DC containing 7 mg of co-crystalized ASTX (L-DC-ASTX), a newly developed highly bioavailable nutraceutical composition of DC containing 2 groups of antioxidants (cocoa flavanols and ASTX). All formulations were given orally, once daily for a month.

MEASUREMENTS

Serum ASTX was measured by high-performance liquid chromatography. Nitric oxide, malonic dialdehyde and oxidized LDL were quantified spectrophotometrically. Oxygenation parameters were evaluated by near-infrared spectroscopy.

RESULTS

One month ingestion of singular formulation of ASTX lead to a 20 fold buildup in serum ASTX level whereas the 4 week ingestion of L-DC-ASTX formulation was accompanied by more prominent accumulation of ASTX in serum (a 40 fold increase over the basal values) at the same daily dose of ASTX. Both antioxidants taken separately decreased serum levels of oxidized LDL and malonic dialdehyde. However effect of L-DC-ASTX formulation was more prominent. ASTX ingested alone caused a borderline increase (p=0.054) in serum nitric oxide (NO) levels, whereas DC ingestion lead to small but statistically significant increase in serum NO concentration. Higher values of NO level were seen after co-ingestion of DC and ASTX, especially in case of L-DC-ASTX formulation suggesting additive/synergistic effects of DC and ASTX on nitric oxide production. These changes were in agreement with the increase in plasma oxygen transport and tissue oxygen saturation seen in the volunteers supplemented with L-DC-ASTX formulation.

CONCLUSION

The nutraceutical formulation of DC and ASTX with an enhanced bioavailability of ASTX can be efficiently used for the correction of oxidative status in aging individuals.

Complexes of lutein with bovine and caprine caseins and their impact on lutein chemical stability in emulsion systems: Effect of arabinogalactan

Lutein is an important xanthophyll carotenoid with many benefits to human health. Factors affecting the application of lutein as a functional ingredient in low-fat dairy-like beverages (pH 6.0-7.0) are not well understood. The interactions of bovine and caprine caseins with hydrophobic lutein were studied using UV/visible spectroscopy as well as fluorescence. Our studies confirmed that the aqueous solubility of lutein is improved after binding with bovine and caprine caseins. The rates of lutein solubilization by the binding to bovine and caprine caseins were as follows: caprine α_S1-II-casein 34%, caprine α_S1-I-casein 10%, and bovine casein 7% at 100 μM lutein. Fluorescence of the protein was quenched on binding supporting complex formation. The fluorescence experiments showed that the binding involves tryptophan residues and some nonspecific interactions. Scatchard plots of lutein binding to the caseins demonstrated competitive binding between the caseins and their sites of interaction with lutein. Competition experiments suggest that caprine α_S1-II casein will bind a larger number of lutein molecules with higher affinity than other caseins. The chemical stability of lutein was largely dependent on casein type and significant increases occurred in the chemical stability of lutein with the following pattern: caprine α_S1-II-casein > caprine α_S1-I-casein > bovine casein. Addition of arabinogalactan to lutein-enriched emulsions increases the chemical stability of lutein-casein complexes during storage under accelerated photo-oxidation conditions at 25°C. Therefore, caprine α_S1-II-casein alone and in combination with arabinogalactan can have important applications in the beverage industry as carrier of this xanthophyll carotenoid (lutein).

Glycyrrhizic acid: A promising carrier material for anticancer therapy

Drug delivery systems have become an integral part of anticancer drugs today. Design of novel drug carriers may lead to significant enhancement in antineoplastic therapy. Glycyrrhizic acid (GL), which is the most important active ingredient extracted from the licorice root shows great potential as a carrier material in this field. Recent studies have indicated that the combination of GL and first-line drugs had better therapeutic effects on cancers. GL showed a series of anti-cancer-related pharmacological activities, such as broad-spectrum anti-cancer ability, resistance to the tissue toxicity caused by chemotherapy and radiation, drug absorption enhancing effects and anti-multidrug resistance (MDR) mechanisms, as a carrier material in drug delivery systems. This review introduced the current research progress on pharmacological mechanisms of GL and development of GL-based drug carriers in anti-cancer field to provide basis for the application prospects of GL. The design of novel GL-based drug delivery systems will bring new opportunities and challenges to anti-cancer therapy.

Natural Poly- and Oligosaccharides as Novel Delivery Systems for Plant Protection Compounds

To increase the bioavailability of plant protection products, we have applied a new approach based on noncovalent association with natural water-soluble polysaccharides and oligosaccharides as delivery systems (DSs). The mechanochemical technique has been applied to prepare the solid-state nanodispersed compositions of antidote 1,8-naphthalic anhydride (NA) with arabinogalactan, sodium salt of carboxymethylcellulose, and glycyrrhizin as DSs. The effect of DSs on the solubility and the penetration of NA into the seeds of barley and wheat has been investigated by various physicochemical techniques. All DSs considerably enhance the solubility of NA and improve its penetration into the grain. The influence of polysaccharides and oligosaccharides on artificial lipid membranes was studied by the NMR relaxation method. It was concluded that the effect of polysaccharides and oligosaccharides on the penetration efficacy of plant protection products might be associated with the detected solubility enhancement and the affinity of DSs to the surface of cell membranes.

Retinal accumulation of zeaxanthin, lutein, and β-carotene in mice deficient in carotenoid cleavage enzymes

Carotenoid supplementation can prevent and reduce the risk of age-related macular degeneration (AMD) and other ocular disease, but until now, there has been no validated and well-characterized mouse model which can be employed to investigate the protective mechanism and relevant metabolism of retinal carotenoids. β-Carotene oxygenases 1 and 2 (BCO1 and BCO2) are the only two carotenoid cleavage enzymes found in animals. Mutations of the bco2 gene may cause accumulation of xanthophyll carotenoids in animal tissues, and BCO1 is involved in regulation of the intestinal absorption of carotenoids. To determine whether or not mice deficient in BCO1 and/or BCO2 can serve as a macular pigment mouse model, we investigated the retinal accumulation of carotenoids in these mice when fed with zeaxanthin, lutein, or β-carotene using an optimized carotenoid feeding method. HPLC analysis revealed that all three carotenoids were detected in sera, livers, retinal pigment epithelium (RPE)/choroids, and retinas of all of the mice, except that no carotenoid was detectable in the retinas of wild type (WT) mice. Significantly higher amounts of zeaxanthin and lutein accumulated in the retinas of BCO2 knockout (bco2^-/-) mice and BCO1/BCO2 double knockout (bco1^-/-/bco2^-/-) mice relative to BCO1 knockout (bco1^-/-) mice, while bco1^-/- mice preferred to take up β-carotene. The levels of zeaxanthin and lutein were higher than β-carotene levels in the bco1^-/-/bco2^-/- retina, consistent with preferential uptake of xanthophyll carotenoids by retina. Oxidative metabolites were detected in mice fed with lutein or zeaxanthin but not in mice fed with β-carotene. These results indicate that bco2^-/- and bco1^-/-/bco2^-/- mice could serve as reasonable non-primate models for macular pigment function in the vertebrate eye, while bco1^-/- mice may be more useful for studies related to β-carotene.

Spectroscopic and molecular dynamics characterization of glycyrrhizin membrane-modifying activity

Glycyrrhizic acid (GA) is a triterpene glycoside extracted from licorice root. Due to its amphiphilicity GA is capable of forming complexes with a variety of hydrophobic molecules, substantially increasing their solubility. GA can enhance the therapeutic effects of various drugs. It was hypothesized that the increased bioavailability of the drug by GA is not only due to increased solubility, but also to enhancement of drug permeability through cell membranes. In this study the interaction of GA with POPC liposomes and model DOPC, POPC and DPPC bilayers was investigated by NMR with addition of shift reagents and MD simulations. This work helps to better understand the mechanism of enhanced drug bioavailability in the presence of GA. NMR and MD reveal that GA does penetrate into the lipid bilayer. NMR shows that GA changes the mobility of lipids. GA is predominantly located in the outer "half-layer" of the liposome and that the middle of the hydrophobic tails is the preferred location. GA freely passes through the bilayer surface to the inner part bringing a few water molecules. Also both approaches indicate pore formation in the presence of GA. The GA interaction with membranes is an additional aspect of the biological activity of GA-based drug delivery systems.

Self-assembly modes of glycyrrhetinic acid esters in view of the crystal packing of related triterpene molecules

The crystal structures of three ester derivatives of glycyrrhetinic acid (GE) are reported. X-ray crystallography revealed that despite differences in the size of the ester substituents (ethyl, isopropyl and 2-morpholinoethyl) the scheme of molecular self-assembly is similar in all three cases but differs significantly from that observed in other known GE esters. According to our analysis, the two basic patterns of self-assembly of GE esters observed in their unsolvated crystals correspond to two distinct orientations of the ester groups relative to the triterpene backbone. Moreover, comparison of the self-assembly modes of GE esters in their unsolvated forms with the supramolecular organization of GE and carbenoxolone in their solvated crystals revealed that ester substituents replace solvent molecules hydrogen bonded to the COOH group at the triterpene skeleton, resulting in similar packing arrangements of these compounds.

Inclusion of terpenes in cyclodextrins: Preparation, characterization and pharmacological approaches

Terpenes constitute the largest class of natural products and are important resources for the pharmaceutical, food and cosmetics industries. However, due to their low water solubility and poor bioavailability there has been a search for compounds that could improve their physicochemical properties. Cyclodextrins (natural and derived) have been proposed for this role and have been complexed with different types of terpenes. This complexation has been demonstrated by using analytical techniques for characterizing complexes such as DSC, NMR, XRD, FTIR, and TGA. The formation of inclusion complexes has been able to improve drug characteristics such as bioavailability, solubility and stability; and to enhance biological activity and efficacy. This review shows strong experimental evidence that cyclodextrins improve the pharmacological properties of terpenes, and therefore need to be recognized as being possible targets for clinical use.