An investigation into the supramolecular structure, solubility, stability and antioxidant activity of rutin/cyclodextrin inclusion complex

Ion Mobility-Mass Spectrometry Strategies to Elucidate the Anhydrous Structure of Noncovalent Guest/Host Complexes

Structural mass spectrometry (MS) techniques are fast and sensitive analytical methods to identify noncovalent guest/host complexation phenomena for desirable solution-phase properties. Current MS-based studies on guest/host complexes of drug and drug-like molecules are sparse, and there is limited guidance on how to interpret MS information in the context of host nanoencapsulation and inclusion. Here, we use structural MS strategies, combining energy-resolved MS (ERMS), ion mobility-MS (IM-MS), and computational modeling, to characterize 14 chemically distinct drug and drug-like compounds for their propensity to form guest/host complexes with the widely used excipient, beta-cyclodextrin (βCD). The majority (11/14) yielded a 1:1 guest/host complex, and ion mobility collision cross section (CCS) analysis provided subtle evidence of gas-phase compaction of complexes in both polarities. The three distinct dissociation channels observed in ERMS (i.e., charged βCD, charged guest, and partial guest loss) were used to direct charge-site assignments for computational modeling, and structural candidates were prioritized using helium-derived CCS measurements combined with root-mean-square distance analysis. The combined analytical information from ERMS, IM-MS, and computational modeling suggested that the majority of anhydrous complexes are inclusion complexes with βCD. Taken together, this work demonstrates a roadmap for how multiple MS-based analytical measurements can be combined to interpret the structures that guest/host complexes adopt in the absence of water.

Development and characterization of pectin-based composite film incorporated with cannabidiol/2,6-di-O-methyl-β-cyclodextrin inclusion complex for food packaging

To reduce environmental pollution and improve human health, developing green active food packaging materials is very necessary. In this study, a novel antioxidant and antibacterial composite film was produced by incorporating inclusion complex (CDIC) of cannabidiol (CBD) with 2,6-di-O-methyl-β-cyclodextrin (DM-β-CD) into pectin. The pectin films loaded with CBD and hemp leaf water extract (HLE) were prepared for comparison. Comprehensive characterizations showed CBD was encapsulated by DM-β-CD and CDIC was evenly dispersed into pectin matrix, forming the compact and intact film. The composite films showed good mechanical properties and biodegradability. CDIC film showed the highest transparency and smoothness (Rrms/Rmax: 2.6/16.8 nm). The addition of bioactives reduced the water-binding capacity and CDIC film had the strongest hydrophobicity. Besides, DM-β-CD encapsulation improved the thermal stability of CBD in CDIC film. Benefiting from encapsulation and excellent bioactivities of CBD, CDIC film showed excellent antioxidant capacity and antibacterial activity, effectively inhibiting colony growth and maintaining the strawberry color in strawberry preservation. This work could provide a novel eco-friendly candidate for food packaging material and expand the use of CBD in food industry.

Antioxidant activity of an inclusion complex between rutin and β-cyclodextrin: experimental and quantum chemical studies

This study aims to synthesize a guest-host complex derived from rutin (Rut) and β-cyclodextrin (β-CD) (denoted as [Rut⊂β-CD]). The obtained substance was characterized by the FT-IR and DSC methods, signifying the formation of an inclusion complex between Rut and β-CD. Complex formation increased the antioxidant activity of rutin corresponding to the decrease of EC50 values from 1.547 × 10-5 mol L-1 to 1.227 × 10-5 mol L-1 according to the DPPH free radical scavenging test. The rutin-β-CD interaction energies were calculated in the vacuum and various solvents (e.g., water, ethanol, and dimethylsulfoxide) utilizing an accurate and broadly parametrized self-consistent tight-binding quantum chemical method (GFN2-xTB). The calculation results reveal the influence of solvent on the structural formation of the rutin-β-CD complex. In both the vacuum and aqueous solution, rutin can enter into the small-sized empty cavity of β-CD, albeit through different terminals, resulting in distinct preferential structures. The presence of organic solvents appears to reduce the interaction between rutin and β-CD, with the interaction strength following the order: water > ethanol > dimethyl sulfoxide.

Rutin/Sulfobutylether-β-Cyclodextrin as a Promising Therapeutic Formulation for Ocular Infection

Ocular pathologies present significant challenges to achieving effective therapeutic results due to various anatomical and physiological barriers. Natural products such as flavonoids, alone or in association with allopathic drugs, present many therapeutic actions including anticancer, anti-inflammatory, and antibacterial action. However, their clinical employment is challenging for scientists due to their low water solubility. In this study, we designed a liquid formulation based on rutin/sulfobutylether-β-cyclodextrin (RTN/SBE-β-CD) inclusion complex for treating ocular infections. The correct stoichiometry and the accurate binding constant were determined by employing SupraFit software (2.5.120) in the UV-vis titration experiment. A deep physical-chemical characterization of the RTN/SBE-β-CD inclusion complex was also performed; it confirmed the predominant formation of a stable complex (Kc, 9660 M-1) in a 1:1 molar ratio, with high water solubility that was 20 times (2.5 mg/mL) higher than the free molecule (0.125 mg/mL), permitting the dissolution of the solid complex within 30 min. NMR studies revealed the involvement of the bicyclic flavonoid moiety in the complexation, which was also confirmed by molecular modeling studies. In vitro, the antibacterial and antibiofilm activity of the formulation was assayed against Staphylococcus aureus and Pseudomonas aeruginosa strains. The results demonstrated a significant activity of the formulation than that of the free molecules.

Cyclodextrins for the Delivery of Bioactive Compounds from Natural Sources: Medicinal, Food and Cosmetics Applications

Cyclodextrins have gained significant and established attention as versatile carriers for the delivery of bioactive compounds derived from natural sources in various applications, including medicine, food and cosmetics. Their toroidal structure and hydrophobic cavity render them ideal candidates for encapsulating and solubilizing hydrophobic and poorly soluble compounds. Most medicinal, food and cosmetic ingredients share the challenges of hydrophobicity and degradation that can be effectively addressed by various cyclodextrin types. Though not new or novel-their first applications appeared in the market in the 1970s-their versatility has inspired numerous developments, either on the academic or industrial level. This review article provides an overview of the ever-growing applications of cyclodextrins in the delivery of bioactive compounds from natural sources and their potential application benefits.

Inclusion Complexes of β-Cyclodextrin with Salvia officinalis Bioactive Compounds and Their Antibacterial Activities

In the present study, the formation of molecular inclusion complexes of Salvia officinalis (sage) bioactive compounds with β-cyclodextrin (β-CD) was evaluated. Sage essential oil (SEO)/β-CD inclusion complexes (ICs) were prepared by co-precipitation at iso-molecular concentrations, and Fourier transform infrared spectroscopy (FT-IR) was applied for the confirmation of the ICs' formation. Quantification of the SEO in the inclusion complexes was performed spectrophotometrically at 273 nm using an SEO standard curve. The SEO and its inclusion complexes were evaluated for their antimicrobial activity against Escherichia coli, Staphylococcus aureus and Listeria monocytogenes. The results showed that β-CD effectively formed inclusion complexes with SEO in satisfactory yields. The antimicrobial activity of the SEO in prepared complexes with β-CD was exhibited against L. monocytogenes and S. aureus and was proportional to their concentrations but was less pronounced.

Estimation of the Controlled Release of Antioxidants from β-Cyclodextrin/Chamomile (Matricaria chamomilla L.) or Milk Thistle (Silybum marianum L.), Asteraceae, Hydrophilic Extract Complexes through the Fast and Cheap Spectrophotometric Technique

This is the first study on the modeling of the controlled release of the estimated antioxidants (flavonoids or flavonolignans) from β-cyclodextrin (β-CD)/hydrophilic vegetable extract complexes and the modeling of transdermal pharmaceutical formulations based on these complexes using an overall estimation by the spectrophotometric method. The Korsmeyer-Peppas model was chosen for evaluating the release mechanisms. β-CD/chamomile (Matricaria chamomilla L., Asteraceae) ethanolic extract and β-CD/milk thistle (Silybum marianum L., Asteraceae) ethanolic extract complexes were obtained by the co-crystallization method with good recovering yields of 55-76%, slightly lower than for β-CD/silibinin or silymarin complexes (~87%). According to differential scanning calorimetry (DSC) and Karl Fischer water titration (KFT), the thermal stability of complexes is similar to β-CD hydrate while the hydration water content is lower, revealing the formation of molecular inclusion complexes. In the Korsmeyer-Peppas model, β-CD/M. chamomilla flower extract complexes reveal Case II transport mechanisms, while the corresponding complexes with leaf extracts indicate non-Fickian diffusion for the controlled release of antioxidants in ethanol 60 and 96%. The same non-Fickian diffusion was revealed by β-CD/S. marianum extract and β-CD/silibinin complexes. On the contrary, almost all model transdermal pharmaceutical formulations based on β-CD/M. chamomilla extract complexes and all those based on β-CD/S. marianum extract complexes revealed non-Fickian diffusion for the antioxidant release. These results indicate that H-bonding is mainly involved in the diffusion of antioxidants into a β-CD based matrix, while the controlled release of antioxidants in model formulations is mainly due to hydrophobic interactions. Results obtained in this study can be further used for studying the particular antioxidants (namely rutin or silibinin, quantified, for example, by liquid chromatographic techniques) for their transdermal transport and biological effects in innovatively designed pharmaceutical formulations that can be obtained using "green" methods and materials.

Synthesis and Evaluation of Rutin–Hydroxypropyl β-Cyclodextrin Inclusion Complexes Embedded in Xanthan Gum-Based (HPMC-g-AMPS) Hydrogels for Oral Controlled Drug Delivery

Oxidants play a significant role in causing oxidative stress in the body, which contributes to the development of diseases. Rutin—a powerful antioxidant—may be useful in the prevention and treatment of various diseases by scavenging oxidants and reducing oxidative stress. However, low solubility and oral bioavailability have restricted its use. Due to the hydrophobic nature of rutin, it cannot be easily loaded inside hydrogels. Therefore, first rutin inclusion complexes (RIC) with hydroxypropyl-β-cyclodextrin (HP-βCD) were prepared to improve its solubility, followed by incorporation into xanthan gum-based (hydroxypropyl methylcellulose-grafted-2-acrylamido -2-methyl-1-propane sulfonic acid) hydrogels for controlled drug release in order to improve the bioavailability. Rutin inclusion complexes and hydrogels were validated by FTIR, XRD, SEM, TGA, and DSC. The highest swelling ratio and drug release occurred at pH 1.2 (28% swelling ratio and 70% drug release) versus pH 7.4 (22% swelling ratio, 65% drug release) after 48 h. Hydrogels showed high porosity (94%) and biodegradation (9% in 1 week in phosphate buffer saline). Moreover, in vitro antioxidative and antibacterial studies (Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli) confirmed the antioxidative and antibacterial potential of the developed hydrogels.

An Innovative Approach for Formulation of Rutin Tablets Targeted for Colon Cancer Treatment

The aim of this study was the improvement of rutin solubility along with targeting its release to colon for effective treatment of colon cancer. Five formulations of compression-coated tablets were prepared with the same core composition including rutin-polyvinyl pyrrolidone K30 solid dispersion (rutin-PVP K30 SD) but differ in being coated with either frankincense alone or different combinations of frankincense with gelatin. The superior formula was selected based on the in vitro drug release then further evaluated in terms of physical properties and in vivo performance in dogs using X-ray. Moreover, in vitro cytotoxicity of rutin, rutin-PVP K30 SD, frankincense, and a mixture of rutin-PVP K30 SD with frankincense in a ratio representing their concentrations in the selected formula was assessed against human colon cancer (HCT-116) cell lines using sulforhodamine B assay. The formula (F4) with the coat consisted of 65%w/w frankincense and 35%w/w gelatin achieved acceptable in vitro controlled drug release. In vivo X-ray in dogs confirmed that F4 tablet could remain intact in the stomach and small intestine until reaching the colon. In vitro cytotoxicity revealed that mixture of rutin-PVP K30 SD with frankincense was more effective in arresting cancer cell growth than rutin or frankincense alone. Moreover, stability studies revealed that F4 tablets were physically and chemically stable. Thus, improving rutin solubility using solid dispersion technique and formulating it into frankincense-based compression-coated (F4) tablets would be a successful approach for colonic delivery of rutin with potential of improving therapeutic efficacy.

Preparation, Characterization and Molecular Dynamics Simulation of Rutin-Cyclodextrin Inclusion Complexes

Rutin is a natural flavonoid that carries out a variety of biological activities, but its application in medicine and food is limited by its water solubility. One of the classical methods used to enhance drug solubility is encapsulation with cyclodextrins. In this paper, the encapsulation of different cyclodextrins with rutin was investigated using a combination of experimental and simulation methods. Three inclusions of rutin/beta-cyclodextrin (β-CD), rutin/2-hydroxypropyl beta-cyclodextrin (HP-β-CD) and rutin/2,6-dimethyl beta-cyclodextrin (DM-β-CD) were prepared by the freeze-drying method, and the inclusions were analyzed using Fourier infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), differential scanning calorimetry (DSC) and ultraviolet-visible spectroscopy (UV) to characterize and demonstrate the formation of the inclusion complexes. Phase solubility studies showed that rutin formed a 1:1 stoichiometric inclusion complex and significantly increased its solubility. β-CD, HP-β-CD, DM-β-CD, rutin and the three inclusion complexes were modeled by using MS2018 and AutoDock 4.0, and molecular dynamics simulations were performed to calculate the solubility parameters, binding energies, mean square displacement (MSD), hydrogen bonding and radial distribution functions (RDF) after the equilibration of the systems. The results of simulation and experiment showed that rutin/DM-β-CD had the best encapsulation effect among the three cyclodextrin inclusion complexes.

Discrimination of β-cyclodextrin/hazelnut (Corylus avellana L.) oil/flavonoid glycoside and flavonolignan ternary complexes by Fourier-transform infrared spectroscopy coupled with principal component analysis

The goal of the study was the discrimination of β-cyclodextrin (β-CD)/hazelnut (Corylus avellana L.) oil/antioxidant ternary complexes through Fourier-transform infrared spectroscopy coupled with principal component analysis (FTIR-PCA). These innovative complexes combine the characteristics of the three components and improve the properties of the resulting material such as the onsite protection against oxidative degradation of hazelnut oil unsaturated fatty acid glycerides. Also, the apparent water solubility and bioaccessibility of the hazelnut oil components and antioxidants can be increased, as well as the controlled release of bioactive compounds (fatty acid glycerides and antioxidant flavonoids, namely hesperidin, naringin, rutin, and silymarin). The appropriate method for obtaining the ternary complexes was kneading the components at various molar ratios (1:1:1 and 3:1:1 for β-CD hydrate:hazelnut oil (average molar mass of 900 g/mol):flavonoid). The recovering yields of the ternary complexes were in the range of 51.5-85.3% and were generally higher for the 3:1:1 samples. The thermal stability was evaluated by thermogravimetry and differential scanning calorimetry. Discrimination of the ternary complexes was easily performed through the FTIR-PCA coupled method, especially based on the stretching vibrations of CO groups in flavonoids and/or CO/CC groups in the ternary complexes at 1014.6 (± 3.8) and 1023.2 (± 1.1) cm^-1 along the second PCA component (PC₂), respectively. The wavenumbers were more appropriate for discrimination than the corresponding intensities of the specific FTIR bands. On the other hand, ternary complexes were clearly distinguishable from the starting β-CD hydrate along the first component (PC₁) by all FTIR band intensities and along PC₂ by the wavenumber of the asymmetric stretching vibrations of the CH groups at 2922.9 (± 0.4) cm^-1 for ternary complexes and 2924.8 (± 1.4) cm^-1 for β-CD hydrate. The first two PCA components explain 70.38% from the variance of the FTIR data (from a total number of 26 variables). Other valuable classifications were obtained for the antioxidant flavonoids, with a high similarity for hesperidin and naringin, according to FTIR-PCA, as well as for ternary complexes depending on molar ratios. The FTIR-PCA coupled technique is a fast, nondestructive and cheap method for the evaluation of quality and similarity/characteristics of these new types of cyclodextrin-based ternary complexes having enhanced properties and stability.

Fabrication of fucoxanthin/2-hydroxypropyl-β-cyclodextrin inclusion complex assisted by ultrasound procedure to enhance aqueous solubility, stability and antitumor effect of fucoxanthin

Fucoxanthin (Fx) possesses multiple bioactivities such as antitumor, antioxidant and anti-inflammatory activities, but its application is limited due to the poor water solubility, low bioavailability, and instability to some external harsh conditions. In this study, a stable inclusion complex of Fx and 2-hydroxypropyl-β-cyclodextrin (2-HP-β-CD) was prepared with the aid of ultrasound, which was characterized by scanning electron microscope, Fourier transform infrared spectroscopy, powder X-ray diffraction, and differential scanning calorimetry techniques. The phase solubility analysis and absorption spectroscopy results showed that Fx formed stoichiometry 1:2 inclusion complex with 2-HP-β-CD, and this could be well proved by molecular simulation. Structural analyses and molecular docking study indicated that Fx was successfully encapsulated into the cavity of 2-HP-β-CD, promoting it soluble in water and stable against heat, storage and gastrointestinal environments. In addition, Fx/2-HP-β-CD inclusion complex exhibited excellent antitumor activity against HCT116 and Caco-2 cell lines with IC₅₀ values of 12.0 μΜ and 14.86 μΜ, respectively. Therefore, it could be a potentially promising way to promote the application of Fx in pharmaceuticals and functional foods by HP-β-CD encapsulation strategy.

Cyclodextrin Derivatives as Promising Solubilizers to Enhance the Biological Activity of Rosmarinic Acid

Rosmarinic acid (RA) is a natural antioxidant with neuroprotective properties; however, its preventive and therapeutic use is limited due to its slight solubility and poor permeability. This study aimed to improve RA physicochemical properties by systems formation with cyclodextrins (CDs): hydroxypropyl-α-CD (HP-α-CD), HP-β-CD, and HP-γ-CD, which were prepared by the solvent evaporation (s.e.) method. The interactions between components were determined by X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC) and Fourier Transform infrared spectroscopy (FTIR). The sites of interaction between RA and CDs were suggested as a result of in silico studies focused on assessing the interaction between molecules. The impact of amorphous systems formation on water solubility, dissolution rate, gastrointestinal (GIT) permeability, and biological activity was studied. RA solubility was increased from 5.869 mg/mL to 113.027 mg/mL, 179.840 mg/mL, and 194.354 mg/mL by systems formation with HP-α-CD, HP-β-CD, and HP-γ-CD, respectively. During apparent solubility studies, the systems provided an acceleration of RA dissolution. Poor RA GIT permeability at pH 4.5 and 5.8, determined by parallel artificial membrane permeability assay (PAMPA system), was increased; RA–HP-γ-CD s.e. indicated the greatest improvement (at pH 4.5 from P_app 6.901 × 10⁻⁷ cm/s to 1.085 × 10⁻⁶ cm/s and at pH 5.8 from 5.019 × 10⁻⁷ cm/s to 9.680 × 10⁻⁷ cm/s). Antioxidant activity, which was determined by DPPH, ABTS, CUPRAC, and FRAP methods, was ameliorated by systems; the greatest results were obtained for RA–HP-γ-CD s.e. The inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) was increased from 36.876% for AChE and 13.68% for BChE to a maximum inhibition of the enzyme (plateau), and enabled reaching IC₅₀ values for both enzymes by all systems. CDs are efficient excipients for improving RA physicochemical and biological properties. HP-γ-CD was the greatest one with potential for future food or dietary supplement applications.

Preparation and Characterization of Rutin–Loaded Zein–Carboxymethyl Starch Nanoparticles

In this work, rutin (RT)–loaded zein–carboxymethyl starch (CMS) nanoparticles were successfully prepared by the antisolvent precipitation method. The effect of CMS on composite nanoparticles at different concentrations was studied. When the ratio of zein–RT–CMS was 10:1:30, the encapsulation efficiency (EE) was the highest, reaching 73.5%. At this ratio, the size of the composite nanoparticles was 196.47 nm, and the PDI was 0.13, showing excellent dispersibility. The results of fluorescence spectroscopy, FTIR, XRD, and CD showed that electrostatic interaction, hydrogen bonding, and hydrophobic interaction were the main driving forces for the formation of nanoparticles. It can be seen from the FE–SEM images that the zein–RT–CMS nanoparticles were spherical. With the increase in the CMS concentration, the particles gradually embedded in the cross–linked network of CMS (10:1:50). After RT was loaded on zein–CMS nanoparticles, the thermal stability and pH stability of RT were improved. The results showed that zein–CMS was an excellent encapsulation material for bioactive substances.

Adsorption of rutin from olive mill wastewater using copolymeric hydrogels based on N-vinylimidazole: Kinetic, equilibrium, and thermodynamics assessments

Olive mill wastewater, also known as olive wastewater, contains biologically active components with various beneficial effects on health. The development of novel adsorbent materials for the recovery of these biologically active substances is important area of research. In this study, copolymeric hydrogels based on N-vinylimidazole (VIm), a new material that has never been used as an adsorbent in the separation of phenolic components, were synthesized. The hydrogels synthesized in this study is copolymer structures based on N-vinylimidazole (VIm) containing [2- (methacryloxy) ethyl] dimethylpentylammonium bromide (QDMAC5) in different moles. QDMAC5 was obtained by quaternization of 2- (dimethylamino) ethyl methacrylate (DMA) with 1-bromopentane (C5). The production of copolymer hydrogels was carried out by free radical solution polymerization. The syntheses were carried out only by changing the monomer composition so that the crosslinker ratio remained constant (1.2 mol%). The QDMAC5 content in the copolymers was 5, 10, 20, 30, and 50 mol%. So, the resulting structures were named PVQ-5%, PVQ-10%, PVQ-20%, PVQ-30%, and PVQ-50%, respectively. Functional group characterizations of hydrogels were made by Fourier Transform Infrared Spectrometry (FTIR). The surface of the hydrogels was analyzed by Scanning Electron Microscopy (SEM). Finally, thermogravimetric analyzes (TGA) were performed to investigate the thermal degradation behavior. The recovery of the rutin present in olive mill wastewater has been investigated as a model study. Kinetic data has been represented by the selected models (pseudo-first order, pseudo-second order, and intraparticle diffusion) convincingly (R² > 0.76), while the equilibrium findings have fitted well to Langmuir, Freundlich, and Temkin equations (R² > 0.77). Rutin adsorption process on N-vinylimidazole (VIm) based copolymeric hydrogels has been found as exothermic and spontaneous chemisorption process depending on the thermodynamic analysis.

Structural Investigation of Hesperetin-7-O-Glucoside Inclusion Complex with β-Cyclodextrin: A Spectroscopic Assessment

Flavonoids are biologically active natural products of great interest for their potential applications in functional foods and pharmaceuticals. A hesperetin-7-O-glucoside inclusion complex with β-cyclodextrin (HEPT7G/βCD; SunActive^® HCD) was formulated via the controlled enzymatic hydrolysis of hesperidin with naringinase enzyme. The conversion rate was nearly 98%, estimated using high-performance liquid chromatography analysis. The objective of this study was to investigate the stability, solubility, and spectroscopic features of the HEPT7G/βCD inclusion complex using Fourier-transform infrared (FTIR), Raman, ultraviolet–visible absorption (UV–vis), ¹H- and ¹³C- nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), liquid chromatography/mass spectroscopy (LC–MS), scanning electron microscopy (SEM), and powdered X-ray diffraction (PXRD) spectroscopic techniques including zeta potential, Job’s plot, and phase solubility measurements. The effects of complexation on the profiles of supramolecular interactions in analytic features, especially the chemical shifts of β-CD protons in the presence of the HEPT7G moiety, were evaluated. The stoichiometric ratio, stability, and solubility constants (binding affinity) describe the extent of complexation of a soluble complex in 1:1 stoichiometry that exhibits a greater affinity and fits better into the β-CD inner cavity. The NMR spectroscopy results identified two different configurations of the HEPT7G moiety and revealed that the HEPT7G/βCD inclusion complex has both –2S and –2R stereoisomers of hesperetin-7-O-glucoside possibly in the –2S/–2R epimeric ratio of 1/1.43 (i.e., –2S: 41.1% and –2R: 58.9%). The study indicated that encapsulation of the HEPT7G moiety in β-CD is complete inclusion, wherein both ends of HEPT7G are included in the β-CD inner hydrophobic cavity. The results showed that the water solubility and thermal stability of HEPT7G were apparently increased in the inclusion complex with β-CD. This could potentially lead to increased bioavailability of HEPT7G and enhanced health benefits of this flavonoid.

A review of transglycosylated compounds as food additives to enhance the solubility and oral absorption of hydrophobic compounds in nutraceuticals and pharmaceuticals

Transglycosylation has been used to modify the physicochemical properties of original compounds. As a result, transglycosylated compounds can form molecular aggregates in size ranges of a few nanometers in an aqueous medium when their concentrations exceed a specific level. Incorporating these hydrophobic compounds has been observed to enhance the solubility of hydrophobic compounds into aggregate structures. Thus, this review introduces four transglycosylated compounds as food additives that can enhance the solubility and oral absorption of hydrophobic compounds. Here, transglycosylated hesperidin, transglycosylated rutin, transglycosylated naringin, and transglycosylated stevia are the focus as representative substances. Significantly, we observed that amorphous formations containing hydrophobic compounds with transglycosylated compounds improved solubility and oral absorption compared to untreated hydrophobic compounds. Moreover, combining transglycosylated compounds with hydrophilic polymers or surfactants enhanced the solubilizing effects on hydrophobic compounds. Furthermore, the enhanced solubility of hydrophobic compounds improved their oral absorption. Transglycosylated compounds also influenced nanoparticle preparation of hydrophobic compounds as a dispersant. This study demonstrated the benefits of transglycosylated compounds in developing supplements and nutraceuticals of hydrophobic compounds with poor aqueous solubility.

Inclusion Complex of Isoliquiritigenin With Sulfobutyl Ether-β-Cyclodextrin: Preparation, Characterization, Inclusion Mode, Solubilization, and Stability

Isoliquiritigenin (ISL) possesses a wide variety of pharmacological properties, however, its poor solubility and oral bioavailability pose a significant barrier to its application. In present studies, the ISL inclusion complex was prepared with sulfobutyl ether-β-cyclodextrin (SBE-β-CD). The physicochemical characterizations of ISL-SBE-β-CD were performed with Fourier transform infrared (FT-IR) spectroscopy and X-ray powder diffraction (XRD). Phase solubility study suggested a 1:1 formation of ISL-SBE-β-CD complexes. The water solubility of ISL rose from 13.6 μM to 4.05 mM by the inclusion of SBE-β-CD. The antioxidant activities (IC50) of ISL-SBE-β-CD reached 42.2 μg/ml, which was significantly lower than that of ISL (60.5 μg/ml). Its stability in biological environments was also enhanced.

Protective effect of rutin and β-cyclodextrin against hepatotoxicity and nephrotoxicity induced by lambda-cyhalothrin in Wistar rats: biochemical, pathological indices and molecular analysis

BACKGROUND

This study aimed to assess hepatotoxicity and nephrotoxicity of Lambda-cyhalothrin (LCT) and the protective effect of rutin alone and in combination with β-cyclodextrin (β-CD).

MATERIALS AND METHODS

Male Wistar rats were divided into five groups: Group 1: was used as a control and received a standard diet and water. Group 2, 3, 4 and 5 were orally administered with LCT (7.6 mg/kg body weight), rutin (200 mg/kg body weight) LCT and rutin (at the same doses as in Group 2 and Group 3), and LCT and a mixture of rutin with β-CD (400 mg/kg body weight), respectively. All experimental animals were orally gavaged 5 days/week for 60 days.

RESULTS

Our data revealed that LCT-induced liver and kidney injuries were related to the up-regulated expression of TNF-α and down-regulated expression of NRF-2 genes mRNA, whereas these effects were reversed with rutin treatment. LCT-induced oxidative stress altered the histological picture, and the hematological and biochemical parameters.

CONCLUSION

Treatment with a rutin-β-CD complex had preventive potential against LCT via suppression of oxidative stress and augmentation of the antioxidant defense system.

Rutin-Loaded Stimuli-Responsive Hydrogel for Anti-Inflammation

An active flavonoid compound rutin was incorporated into a guanosine phenylborate hydrogel (GBR) by a stimuli-responsive borate ester linkage for the treatment of inflammatory bowel disease (IBD). The components and morphology of the drug delivery system were characterized by NMR, UV-vis spectroscopy, and AFM. Rheological measurements revealed the required injectability and self-healing ability, which contributed to its application in rectal administration. The cell assays proved the excellent compatibility and safety of the system, and a possible pathway to form multicellular aggregates. In vitro drug-release studies showed that the hydrogel exhibited good stability in physiological medium, and the drug was almost completely released (more than 90 wt % after 24 h of incubation) in acidic pH and excessive ROS-containing medium, realizing the dual-responsive release of pH/ROS. In vivo activities of the GBR hydrogel showed higher therapeutic efficacy than free rutin in a colitis mice model, and it could significantly inhibit overexpressed inflammatory cytokines, including TNF-α and IL-6. Degradation studies of the hydrogel provided further evidence for the safety of its in vivo application. The work provided a simple strategy to prepare a G-quadruplex drug carrier, which was expected to achieve multi-drug delivery.

Preparation and Properties of Cyclodextrin Inclusion Complexes of Hyperoside

In order to improve the aqueous solubility and enhance the bioavailability of Hyperoside (Hyp), three inclusion complexes (ICs) of Hyp with 2-hydroxypropyl-β-cyclodextrin (2H-β-CD), β-cyclodextrin (β-CD), and methyl-β-cyclodextrin (M-β-CD) were prepared using the ultrasonic method. The characterization of the inclusion complexes (ICs) was achieved using Fourier-transform infrared spectroscopy (FTIR), scanning electronic microscopy (SEM), X-ray powder diffraction (XRPD), thin-layer chromatography (TLC), and ¹H nuclear magnetic resonance (¹H NMR). The effects of the ICs on the solubility and antioxidant activity of Hyp were investigated. A Job’s plot revealed that the Hyp formed ICs with three kinds of cyclodextrin (CD), all at a 1:1 stoichiometric ratio. The FTIR, SEM, XRPD, TLC, and ¹H NMR results confirmed the formation of inclusion complexes. The water solubility of the IC of Hyp with 2-hydroxypropyl-β-cyclodextrin was enhanced 9-fold compared to the solubility of the original Hyp. The antioxidant activity tests showed that the inclusion complexes had higher antioxidant activities compared to free Hyp in vitro and the H₂O₂–RAW264.7 cell model. Therefore, encapsulation with CDs can not only improve Hyp’s water solubility but can also enhance its biological activity, which provides useful information for the potential application of complexation with Hyp in a clinical context.

Rutin-loaded polymeric nanorods alleviate nephrolithiasis by inhibiting inflammation and oxidative stress in vivo and in vitro

Polycrystalline aggregates formed in the glomerulus or other components of the urinary system represent the most critical step in kidney stone formation. The most common form of these crystals is calcium oxalate monohydrate (CaC₂O₄·H₂O). Rutin is a potent antioxidant phytochemical, however, hydrophobicity and limited bioavailability restrain it from clinical applications. We developed a biocompatible amphiphilic triblock copolymer, PLGA-PEG-PLGA-loaded rutin nanorods, by simple and efficient self-assembly. Incorporation of polymer changed the topology of crystalline rutin into nanorods with non-Fickian sustained drug release kinetics by the Korsmeyer-Peppas model and thermodynamically non-spontaneous release of rutin. Rutin nanorods changed the growth and morphology of CaC₂O₄ crystals from the monohydrate to dihydrate form by increased adsorption and specific surface area from 0.8027 to 5.4233 m² g^-1, respectively. Rutin nanorods restored cell viability and oxidative stress in MDCK cells by modulating OPN expression and counteracts the proinflammatory signaling in THP-1 macrophages triggered by CaC₂O₄ crystals (80 μg cm^-2). Rutin nanorods resulted in significant protection in serum and urinary biochemistry with reduced calcifications and increased tissue viability of kidneys without any toxicity and achieved high bioavailability. Our data provide a facile strategy for the use of rutin nanorods as a targeted drug system to treat and prevent renal stone formations.

Characteristic of Cyclodextrins: Their Role and Use in the Pharmaceutical Technology

About 40% of newly-discovered entities are poorly soluble in water, and this may be an obstacle in the creation of new drugs. To address this problem, the present review article examines the structure and properties of cyclodextrins and the formation and potential uses of drug - cyclodextrin inclusion complexes. Cyclodextrins are cyclic oligosaccharides containing six or more D-(+)- glucopyranose units linked by α-1,4-glycosidic bonds, which are characterized by a favourable toxicological profile, low local toxicity and low mucous and eye irritability; they are virtually non-toxic when administered orally. They can be incorporated in the formulation of new drugs in their natural form (α-, β-, γ-cyclodextrin) or as chemically-modified derivatives. They may also be used as an excipient in drugs delivered by oral, ocular, dermal, nasal and rectal routes, as described in the present paper. Cyclodextrins are promising compounds with many beneficial properties, and their use may be increasingly profitable for pharmaceutical scientists.

Analytical and in silico study of the inclusion complexes between tropane alkaloids atropine and scopolamine with cyclodextrins

Datura stramonium L. (Solanaceae) possesses a rich tropane alkaloids (TAs) spectrum. The plant contains, in particular, the allelopathic compounds scopolamine and atropine, which are poorly soluble in water, thus limiting their use in agrochemical formulations as biocidal and deterrent agents against herbivore insects. The efficacy of the hydrophobic TAs extracts could be increased with the improvement of their dissolution/leaching properties. This is important for improving screening and test performance and for elucidating the activity of environmentally friendly agricultural approaches, with new perspectives for the production and use of those biodegradable insecticidal products. The present study explores the aspects of atropine and scopolamine complexation with cyclodextrin (CDs) through FT-IR and UV–Vis spectroscopies. In addition, the structures of the inclusion complex of atropine, scopolamine and β-CD have been investigated by molecular modeling techniques. The results obtained indicate that β-CDs are a promising carriers for improving the properties of TAs, therefore increasing their application potential in agrochemical formulations.

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Impact of rutin on the foaming properties of soybean protein: Formation and characterization of flavonoid-protein complexes

The aims of present study were to determine the impact of rutin complexation on the ability of soybean protein isolates (SPI) to form and stabilize foams and its mechanism. At pH 7.0, the foaming capacity and foaming stability of the rutin-SPI complexes (28.33% and 14.22%) was appreciably changed when compared with that of SPI alone (19.64% and 32.95%). The improvement in foaming properties was mainly attributed to decrease gas bubble size and increase interfacial thickness as suggested by light microscopy analysis. UV-visible spectroscopy showed that the absorption peak of the SPI was increased and red shifted after complexation with rutin. ITC confirmed that there was an interaction between rutin and SPI. This interaction was hydrophobic interaction and the binding process was entropy driven. This study shows that the foaming properties of plant-based proteins can be improved by forming complexes with flavonoids, which may be useful for foaming agents in foods.

Cyclodextrin Monomers and Polymers for Drug Activity Enhancement

Cyclodextrins (CDs) and cyclodextrin (CD)-based polymers are well-known complexing agents. One of their distinctive features is to increase the quantity of a drug in a solution or improve its delivery. However, in certain instances, the activity of the solutions is increased not only due to the increase of the drug dose but also due to the drug complexation. Based on numerous studies reviewed, the drug appeared more active in a complex form. This review aims to summarize the performance of CDs and CD-based polymers as activity enhancers. Accordingly, the review is divided into two parts, i.e., the effect of CDs as active drugs and as enhancers in antimicrobials, antivirals, cardiovascular diseases, cancer, neuroprotective agents, and antioxidants.

Molecular mechanisms of anticancer effect of rutin

Because of the extensive biological functions of natural substances such as bioflavonoids, and their high safety and low costs, they could have high priority application in the health care system. The antioxidant properties of rutin, a polyphenolic bioflavonoid, have been well documented and demonstrated a wide range of pharmacological applications in cancer research. Since chemotherapeutic drugs have a wide range of side effects and rutin is a safe anticancer agent with minor side effects so recent investigations are performed for study of mechanisms of its anticancer effect. Both in-vivo and in-vitro examinations on anticancer mechanisms of this natural agent have been widely carried out. Regulation of different cellular signaling pathways such as Wnt/β-catenin, p53-independent pathway, PI3K/Akt, JAK/STAT, MAPK, p53, apoptosis as well as NF-ĸB signaling pathways helps to mediate the anticancer impacts of this agent. This study tried to review the molecular mechanisms of rutin anticancer effect on various types of cancer. Deep exploration of these anticancer mechanisms can facilitate the development of this beneficial compound for its application in the treatment of different cancers.

Sunscreens Containing Cyclodextrin Inclusion Complexes for Enhanced Efficiency: A Strategy for Skin Cancer Prevention

Unprotected exposure of skin to solar ultraviolet radiation (UVR) may damage the DNA of skin cells and can lead to skin cancer. Sunscreens are topical formulations used to protect skin against UVR. The active ingredients of sunscreens are UV filters that absorb, scatter, and/or reflect UVR. Preventing the formation of free radicals and repairing DNA damages, natural antioxidants are also added to sunscreens as a second fold of protection against UVR. Antioxidants can help stabilise these formulations during the manufacturing process and upon application on skin. However, UV filters and antioxidants are both susceptible to degradation upon exposure to sunlight and oxygen. Additionally, due to their poor water solubility, natural antioxidants are challenging to formulate and exhibit limited penetration and bioavailability in the site of action (i.e., deeper skin layers). Cyclodextrins (CDs) are cyclic oligosaccharides that are capable of forming inclusion complexes with poorly soluble drugs, such as antioxidants. In this review, we discuss the use of CDs inclusion complexes to enhance the aqueous solubility of antioxidants and chemical UV filters and provide a protective shield against degradative factors. The role of CDs in providing a controlled drug release profile from sunscreens is also discussed. Finally, incorporating CDs inclusion complexes into sunscreens has the potential to increase their efficiency and hence improve their skin cancer prevention.

Physico-Chemical and Pharmaco-Technical Characterization of Inclusion Complexes Formed by Rutoside with β-Cyclodextrin and Hydroxypropyl-β-Cyclodextrin Used to Develop Solid Dosage Forms

The aim of our study was to obtain rutoside (RUT) inclusion complexes in β-cyclodextrin (β-CD) and in hydroxypropyl-β-cyclodextrin (HP-β-CD), in a 1:1 molar ratio, using the lyophilization method of complexation in solution. The complexes were confirmed and characterized, in comparison with the raw materials and their simple physical mixtures, by SEM, DSC, and FT-IR analyses. The antioxidant activity of the compounds was assessed by using the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and 2’-azino-bis(3-ethylbenzothiazolin-6-sulfonic) acid (ABTS) radicals, determining the radical scavenging activity, and by ferric reducing antioxidant power (FRAP) assay. The results revealed superior antioxidant ability for the inclusion complexes towards rutoside alone. The inclusion complexes were used as active ingredients in formulations of immediate-release tablets. The preformulation studies were performed on the powders for direct compression obtained after mixing the active ingredients with the excipients (Avicel PH 102, Polyplasdone XL-10, magnesium stearate, and talc). The materials were assessed for particle size, flowability, compressibility, and moisture content, establishing they are suitable for a direct compression process. The tablets were characterized regarding their pharmaco-technical properties and the results proved that the formulations lead to high-quality delivery systems, showing a good mechanical resistance with a low friability, excellent disintegration times, and satisfying dissolution rate. The performances were very similar for both formulations and the physico-mechanical properties of the tablets are not influenced by type of the used cyclodextrin, but the RUT- HP-β-CD tablets presented a higher dissolution rate.

The anticancer potential of the dietary polyphenol rutin: Current status, challenges, and perspectives

Rutin is one of the most common dietary polyphenols found in vegetables, fruits, and other plants. It is metabolized by the mammalian gut microbiota and absorbed from the intestines, and becomes bioavailable in the form of conjugated metabolites. Rutin exhibits a plethora of bioactive properties, making it an extremely promising phytochemical. Numerous studies demonstrate that rutin can act as a chemotherapeutic and chemopreventive agent, and its anticancer effects can be mediated through the suppression of cell proliferation, the induction of apoptosis or autophagy, and the hindering of angiogenesis and metastasis. Rutin has been found to modulate multiple molecular targets involved in carcinogenesis, such as cell cycle mediators, cellular kinases, inflammatory cytokines, transcription factors, drug transporters, and reactive oxygen species. This review summarizes the natural sources of rutin, its bioavailability, and in particular its potential use as an anticancer agent, with highlighting its anticancer mechanisms as well as molecular targets. Additionally, this review updates the anticancer potential of its analogs, nanoformulations, and metabolites, and discusses relevant safety issues. Overall, rutin is a promising natural dietary compound with promising anticancer potential and can be widely used in functional foods, dietary supplements, and pharmaceuticals for the prevention and management of cancer.

Applications of nuclear magnetic resonance spectroscopy to the evaluation of complex food constituents

Due to a number of unparalleled advantages such as fastness, accuracy, intactness, nuclear magnetic resonance spectroscopy (NMR) has fulfilled a significant role in determining structures and dynamics of various physical, chemical and biological systems in the field of food analysis. This study introduced the principle of NMR, key NMR techniques such as ¹H NMR, DOSY, NOESY, HSQC, etc., and the knowledge of NMR applications on the evaluation of complex food system, especially the interactions of food components. The reviewed research work provides sufficient evidence that NMR spectroscopy has been an invaluable tool and will play an increasingly important role in specific technical support for food assessment. In addition, NMR combined with various other technologies could give a complete picture of the mechanism of the performance of functional food compounds, which are vital for human health and influence the intrinsic food properties during processing, storage and transportation at the molecular level.

Study on the preparation of geranyl acetone and β-cyclodextrin inclusion complex and its application in cigarette flavoring

β-Cyclodextrin (β-CD) inclusion complex containing geranyl acetone as a guest was prepared by saturated water solution method. Furthermore, the structure and properties of the inclusion complex were studied. The formation of the inclusion complex was demonstrated by. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (X-RD), thermogravimetric analysis (TG) and differential scanning calorimetry (DSC). The thermodynamic analysis of the inclusion complex showed that the inclusion reaction is an endothermic spontaneous reaction. The average of △H, △S and △G is 11.66 kJ mol-1, 0.082 kJ mol-1 and - 14.49 kJ mol-1, respectively. Moreover, the kinetic analysis of thermal decomposition of the inclusion compound showed that the thermal decomposition reaction is a first-order reaction (the inclusion ratio is 1:1), the average activation energy of the reaction is 180.90 kJ mol-1, and the binding force in the inclusion compound is mainly Van der Waals force. The flavor test of cigarettes showed that the inclusion compound improved the stability of geranyl acetone and the sensory quality of cigarettes. This study improves the solubility and thermal stability of geranyl acetone, and provides theoretical support and technical guidance for expanding the application of geranyl acetone.

Rutin-Loaded Poloxamer 407-Based Hydrogels for In Situ Administration: Stability Profiles and Rheological Properties

Rutin is a flavone glycoside contained in many plants, and exhibits antioxidant, anti-inflammatory, anticancer, and wound-healing properties. The main disadvantage related to the use of this molecule for pharmaceutical application is its poor bioavailability, due to its low solubility in aqueous media. Poloxamer 407-hydrogels show interesting thermo-sensitive properties that make them attractive candidates as pharmaceutical formulations. The hydrophobic domains in the chemical structure of the copolymer, a polymer made up of two or more monomer species, are useful for retaining poorly water-soluble compounds. In this investigation various poloxamer 407-based hydrogels containing rutin were developed and characterized as a function of the drug concentration. In detail, the Turbiscan stability index, the micro- and dynamic rheological profiles and in vitro drug release were investigated and discussed. Rutin (either as a free powder or solubilized in ethanol) did not modify the stability or the rheological properties of these poloxamer 407-based hydrogels. The drug leakage was constant and prolonged for up to 72 h. The formulations described are expected to represent suitable systems for the in situ application of the bioactive as a consequence of their peculiar versatility.