Experimental and Theoretical Investigations on the Supermolecular Structure of Isoliquiritigenin and 6-O-α-D-Maltosyl-β-cyclodextrin Inclusion Complex

Colon-specific delivery of isoliquiritigenin by oral edible zein/caseate nanocomplex for ulcerative colitis treatment

Although a natural anti-inflammatory ingredient, isoliquiritigenin (ISL), plays an effective role in ulcerative colitis (UC) treatment, a series of drawbacks still limit its clinical application, including the poor solubility, instability in gastrointestinal tract, and rapid elimination rate of ISL. Zein-based NPs display the benefits on drug loading and delivery, whereas with the poor stability. In this study, an edible nano-system composed by zein/caseinate complex was fabricated for the colon-targeting delivery of ISL, to improve its colon retention and anti-UC effects. The optimized ISL loaded zein/caseinate NPs (ISL@NPs) were prepared by single-factor design by anti-solvent precipitation method, and then characterized. The improved cellular uptake of ISL@NPs on NCM460 and RAW 264.7 cells was evaluated in vitro. The colon tissue permeability and retention capacity in vivo, and the anti-UC efficacy of ISL@NPs in DSS-induce UC were implemented. As a result, ISL@NPs with the high drug loading efficiency of 9.39% ± 0.26%, the average particle diameter of 137.32 ± 2.54 nm, exhibited the pH-sensitive stability in the different simulated gastrointestinal buffer. Compared with free ISL, ISL@NPs showed significantly higher cellular uptake ability in NCM460 and RAW 264.7 cells. Based on in vivo imaging system, zein/caseinate NPs showed the prolonged colonic retention and the enhanced penetration into the colonic epithelium. Finally, the oral administration of ISL@NPs could effectively alleviate the UC-related symptoms, down-regulate the production of pro-inflammatory factors, and reduce the infiltration of macrophages and neutrophils in colon tissues. In this study, an oral colon-specific nano-system, composed with the natural compound and edible materials, was developed as the promising alternatives in the prevention and treatment of UC.

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.

Targeting Nrf2-Mediated Oxidative Stress Response in Traumatic Brain Injury: Therapeutic Perspectives of Phytochemicals

Traumatic brain injury (TBI), known as mechanical damage to the brain, impairs the normal function of the brain seriously. Its clinical symptoms manifest as behavioral impairment, cognitive decline, communication difficulties, etc. The pathophysiological mechanisms of TBI are complex and involve inflammatory response, oxidative stress, mitochondrial dysfunction, blood-brain barrier (BBB) disruption, and so on. Among them, oxidative stress, one of the important mechanisms, occurs at the beginning and accompanies the whole process of TBI. Most importantly, excessive oxidative stress causes BBB disruption and brings injury to lipids, proteins, and DNA, leading to the generation of lipid peroxidation, damage of nuclear and mitochondrial DNA, neuronal apoptosis, and neuroinflammatory response. Transcription factor NF-E2 related factor 2 (Nrf2), a basic leucine zipper protein, plays an important role in the regulation of antioxidant proteins, such as oxygenase-1(HO-1), NAD(P)H Quinone Dehydrogenase 1 (NQO1), and glutathione peroxidase (GPx), to protect against oxidative stress, neuroinflammation, and neuronal apoptosis. Recently, emerging evidence indicated the knockout (KO) of Nrf2 aggravates the pathology of TBI, while the treatment of Nrf2 activators inhibits neuronal apoptosis and neuroinflammatory responses via reducing oxidative damage. Phytochemicals from fruits, vegetables, grains, and other medical herbs have been demonstrated to activate the Nrf2 signaling pathway and exert neuroprotective effects in TBI. In this review, we emphasized the contributive role of oxidative stress in the pathology of TBI and the protective mechanism of the Nrf2-mediated oxidative stress response for the treatment of TBI. In addition, we summarized the research advances of phytochemicals, including polyphenols, terpenoids, natural pigments, and otherwise, in the activation of Nrf2 signaling and their potential therapies for TBI. Although there is still limited clinical application evidence for these natural Nrf2 activators, we believe that the combinational use of phytochemicals such as Nrf2 activators with gene and stem cell therapy will be a promising therapeutic strategy for TBI in the future.

Application of starch-based nanoparticles and cyclodextrin for prebiotics delivery and controlled glucose release in the human gut: a review

Starches are a major constituent of staple foods and are the main source of energy in the human diet (55-70%). In the gastrointestinal tract, starches are hydrolyzed into glucose by α-amylase and α-glucosidase, which leads to a postprandial glucose elevation. High levels of blood glucose levels over sustained periods may promote type 2 diabetes mellitus (T2DM) and obesity. Increasing consumption of starchy foods with a lower glycemic index may therefore contribute to improved health. In this paper, the preparation and properties of several starch-based nanoparticles (SNPs) and cyclodextrins (CDs) derivatives are reviewed. In particular, we focus on the various mechanisms responsible for the ability of these edible nanomaterials to modulate glucose release and the gut microbiome in the gastrointestinal tract. The probiotic functions are achieved through encapsulation and protection of prebiotics or bioactive components in foods or the human gut. This review therefore provides valuable information that could be used to design functional foods for improving human health and wellbeing.

Rational formulation engineering of fraxinellone utilizing 6-O-α-D-maltosyl-β-cyclodextrin for enhanced oral bioavailability and hepatic fibrosis therapy

Although Fraxinellone (Frax) isolated from Dictamnus albus L. possessed excellent anti-hepatic fibrosis activity, oral administration of Frax suffered from the inefficient therapeutic outcome in vivo due to negligible oral absorption. At present, the oral formulation of Frax is rarely exploited. For rational formulation design, we evaluated preabsorption risks of Frax and found that Frax was rather stable while poorly dissolved in the gastrointestinal tract (78.88 μg/mL), which predominantly limited its oral absorption. Further solubility test revealed the outstanding capacity of cyclodextrin derivatives (CDs) to solubilize Frax (6.8-12.8 mg/mL). This led us to study the inclusion complexes of Frax with a series of CDs and holistically explore their drug delivery performance. Characterization techniques involving ¹H-NMR, FT-IR, DSC, PXRD, and molecular docking confirmed the most stable binding interactions when Frax complexed with 6-O-α-D-maltosyl-β-cyclodextrin (G₂-β-CD-Frax). Notably, G₂-β-CD-Frax exhibited the highest solubilizing capacity, fast dissolution rate, and superior Caco-2 cell internalization with no obvious toxicity. Pharmacokinetic studies demonstrated markedly higher oral bioavailability of G₂-β-CD-Frax (5.8-fold that of free drug) than other Frax-CDs. Further, long-term administration of G₂-β-CD-Frax (5 mg/kg) efficiently inhibited CCl₄-induced hepatic fibrosis in the mouse without inducing any toxicity. Our results will inspire the continued advancement of optimal oral Frax formulations for anti-fibrotic therapy.

Red Propolis as a Source of Antimicrobial Phytochemicals: Extraction Using High-Performance Alternative Solvents

Propolis is a resinous material rich in flavonoids and involved in several biological activities such as antimicrobial, fungicide, and antiparasitic functions. Conventionally, ethanolic solutions are used to obtain propolis phytochemicals, which restrict their use in some cultures. Given this, we developed an alcohol-free high-performance extractive approach to recover antibacterial and antioxidants phytochemicals from red propolis. Thus, aqueous-solutions of ionic liquids (IL) and eutectic solvents were used and then tested for their total flavonoids, antioxidant, and antimicrobial activities. The surface-responsive technique was applied regarding some variables, namely, the time of extraction, the number of extractions, and cavitation power (W), to optimize the process (in terms of higher yields of flavonoids and better antioxidant activity). After that, four extractions with the same biomass (repetitions) using 1-hexyl-3-methylimidazolium chloride [C6mim]Cl, under the operational conditions fixed at 3.3 min and 300 W, were able to recover 394.39 ± 36.30 mg RuE. g-1 of total flavonoids, with total antioxidant capacity evaluated up to 7595.77 ± 5.48 μmol TE. g-1 dried biomass, besides inhibiting the growth of Staphylococcus aureus and Salmonella enteritidis bacteria (inhibition halo of 23.0 ± 1.0 and 15.7 ± 2.1, respectively). Aiming at the development of new technologies, the antimicrobial effect also presented by [C6mim]Cl may be appealing, and future studies are required to understand possible synergistic actions with propolis phytochemicals. Thereby, we successfully applied a completely alcohol-free method to obtain antimicrobials phytochemicals and highly antioxidants from red propolis, representing an optimized process to replace the conventional extracts produced until now.

Effect of pH on Isoliquiritigenin (ISL) fluorescence in lipo- polymeric system and metallic nanosystem

Flavonoids have various medicinal properties such as anti-inflammatory, anti-oxidant, anti-cancer, antiviral. Yet, the fluorescent properties of flavonoids are less explored and termed as autofluorescence in general. This study investigates the fluorescence properties of Isoliquiritigenin (ISL) in various alkaline conditions. The maximum fluorescence emission was obtained at pH 12 on excitation wavelength of 440 nm. Theoretical and experimental investigation on the shift in UV-Vis absorbance spectra, upon the variation in pH, performed, indicated deprotonation as the cause. PEG-based stable liposome carrier, with an internal alkaline environment (LIP-ISL-NaOH) that aids in flavonoid fluorescence, was synthesized using a modified thin-film hydration method. The hydrodynamic size of the liposome synthesized was in the range of 50-70 nm. PEG, on the addition, found maintaining the alkaline environment in the internal chamber of the lipo-polymer system, helps the LIP-ISLNaOH nanosystem to exhibit fluorescence irrespective of the suspension pH. Further, reducing property of ISL was used for the synthesis of Au nanoclusters to achieve theranostic nature.

Development of an Orally Bioavailable Isoliquiritigenin Self-Nanoemulsifying Drug Delivery System to Effectively Treat Ovalbumin-Induced Asthma

Purpose

Isoliquiritigenin (ILQ), an important component of Anti-Asthma Herbal Medicine Intervention (ASHMI), had shown potent anti-asthma effect in vitro in our previous study. However, poor solubility and low bioavailability hindered in vivo application to treat asthma. This study was to develop a novel ILQ loaded self-nanoemulsifying drug delivery system (ILQ-SMEDDS) with enhanced bioavailability.

Methods

The optimized SMEDDS formulation was composed of ethyl oleate (oil phase), Tween 80 (surfactant) and PEG400 (co-surfactant) at a mass ratio of 3:6:1. The physiochemical properties of ILQ-SMEDDS, including drug content, globule size, zeta potential, scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, were characterized. And the in vitro release profile, in situ intestinal absorption, in vivo pharmacokinetic parameters and the anti-asthma effect of ILQ suspension and ILQ-SMEDDS were evaluated.

Results

The ILQ-SMEDDS had an average globule size of 20.63 ± 1.95 nm with a polydispersity index (PDI) of 0.11 ± 0.03, and its zeta potential was −12.64 ± 2.12 mV. The cumulative release rate of ILQ from ILQ-SMEDDS to the simulated gastrointestinal tract was significantly higher than that of free ILQ suspension. And area under curve with ILQ-SMEDDS was found to be 3.95 times higher than that of ILQ suspension indicating improved bioavailability by SMEDDS. Although ILQ-SMEDDS showed a slight less effective inhibitory effect on eotaxin-1 in human lung fibroblast (HFL-1) cells than free ILQ, in an ovalbumin-induced asthma model, ILQ-SMEDDS exhibited more efficacy than ILQ suspension in improving asthma-associated inflammation, including eosinophil production, ovalbumin-specific immunoglobulin E (OVA-sIgE), interleukin 4 (IL 4), interleukin 5 (IL 5) and interferon-γ (IFN-γ). Even the low dose of ILQ-SMEDDS group (10 mg/kg) showed better anti-asthma effect than that of the ILQ suspension group (20 mg/kg).

Conclusion

Compared with ILQ suspension, ILQ-SMEDDS showed significantly improved bioavailability and anti-asthma effect, revealing its potential as a favorable pharmaceutical agent for treating asthma.

Licorice isoliquiritigenin-encapsulated mesoporous silica nanoparticles for osteoclast inhibition and bone loss prevention

Mesoporous silica nanoparticles (MSNs) are extensively used in bone tissue regeneration and local drug delivery. However, the effects of MSNs alone on osteoclast formation and function, as well as the utilization of MSNs to deliver natural molecules against bone resorption, remain unexplored. Here, we report the development of licorice-derived bioactive flavonoid isoliquiritigenin (ISL)-encapsulated MSNs (MSNs-ISL) as a potent bone-bioresponsive nanoencapsulation system for prevention of osteoclast-mediated bone loss in vitro and in vivo.

Methods: We synthesized MSNs-ISL and then investigated the drug loading and release characteristics of the resulting nanoparticles. In vitro experiments on osteoclast differentiation and bone resorption were performed using mouse primary bone marrow-derived macrophages (BMMs). In vivo animal experiments were conducted using a lipopolysaccharide (LPS)-mediated calvarial bone erosion model.

Results: The resulting MSNs-ISL were spherical and highly monodispersed; they possessed a large specific surface area and superior biocompatibility, and allowed acid-sensitive sustained drug release. Compared with free ISL and MSNs alone, MSNs-ISL significantly and additively inhibited receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast generation, decreased the size and quantity of sealing zones, and reduced the osteolytic capacity of osteoclasts in vitro. MSNs-ISL treatment also downregulated RANKL-stimulated mRNA expression of osteoclast-associated genes and transcription factors. Mechanistically, MSNs-ISL remarkably attenuated the RANKL-initiated expression of tumor necrosis factor receptor-associated factor 6 (TRAF6), phosphorylation of mitogen-activated protein kinases (MAPKs), and phosphorylation and degradation of inhibitor of κBα (IκBα), together with the nuclear translocation of nuclear factor-κB (NF-κB) p65 and the activator protein (AP)-1 component c-Fos. Moreover, MSNs-ISL almost completely restrained the expression of nuclear factor of activated T cells (NFATc1). Consistent with the in vitro results, MSNs-ISL could block osteoclast activity; relieve inflammation-related calvarial bone destruction in vivo; and suppress c-Fos, NFATc1, and cathepsin K expression levels.

Conclusion: Licorice ISL-encapsulated MSNs exhibit notable anti-osteoclastogenetic effects and protect against inflammatory bone destruction. Our findings reveal the feasibility of applying MSNs-ISL as an effective natural product-based bone-bioresponsive nanoencapsulation system to prevent osteoclast-mediated bone loss.

Enhancement of Oral Bioavailability and Anti-hyperuricemic Activity of Isoliquiritigenin via Self-Microemulsifying Drug Delivery System

The aim of this study was to develop a self-microemulsifying drug delivery system (SMEDDS) for enhancement of the oral bioavailability of isoliquiritigenin (ISL) as well as evaluate its in vivo anti-hyperuricemic effect in rats. The ISL-loaded self-microemulsifying drug delivery system (ISL-SMEDDS) was comprised of ethyl oleate (EO, oil phase), Tween 80 (surfactant), and PEG 400 (co-surfactant). The ISL-SMEDDS exhibited an acceptable narrow size distribution (44.78 ± 0.35 nm), negative zeta potential (- 10.67 ± 0.86 mV), and high encapsulation efficiency (98.17 ± 0.24%). The in vitro release study indicated that the release rates of the formulation were obviously higher in different release media (HCl, pH 1.2; PBS, pH 6.8; double-distilled water, pH 7.0) compared with the ISL solution. The oral bioavailability of the ISL-SMEDDS was enhanced by 4.71 times in comparison with the free ISL solution. More importantly, ISL-SMEDDS significantly reduced uric acid level by inhibiting xanthine oxidase (XOD) activity in the model rats. Collectively, the prepared ISL-SMEDDS proved to be potential carriers for enhancing the solubility and oral bioavailability of ISL, as well as ameliorating its anti-hyperuricemic effect.

Preparation and evaluation of isoliquiritigenin-loaded F127/P123 polymeric micelles

Isoliquiritigenin (ISL) possesses a variety of pharmacological activities amid poor solubility in water which has restricted its clinical application. In this study, isoliquiritigenin-loaded F127/P123 polymeric micelles (ISL-FPM) were successfully prepared and evaluated in vitro and in vivo. The particle size, polydispersity index, and zeta potential of the selected formulation were 20.12 ± 0.72 nm, 0.183 ± 0.046, and -38.31 ± 0.33 mV, respectively, coupled with high encapsulation efficiency of 93.76 ± 0.31%. Drug-loading test showed the solubility of ISL after formulating into micelles was 232 times higher than its intrinsic solubility. Moreover, critical micelle concentration (CMC) was tested with fluorescence probe method and turned out to be quite low, which implied high stability of ISL-FPM. Release profile in HCl (pH 1.2), double distilled water, and PBS (pH 7.4) of ISL-FPM reached over 80%, while free ISL was around 40%. Pharmacokinetic research revealed that formulated ISL-FPM significantly increased bioavailability by nearly 2.23-fold compared to free ISL. According to the results of in vitro antioxidant activity, scavenging DPPH activity of ISL was significantly strengthened when it was loaded into polymeric micelles. Altogether, ISL-FPM can act as a promising approach to improve solubility as well as enhance bioavailability and antioxidant activity of ISL.

Effect of Pulsed Therapeutic Ultrasound and Diosmin on Skeletal Muscle Oxidative Parameters

Cyclodextrins (CDs) have been widely used as a promising alternative in the formation of inclusion complexes with poorly soluble molecules. From this perspective, the present study aimed to study the inclusion complexes of diosmin in β-cyclodextrin, chemically quantify the diosmin-in-gel preparation and analyze the stability of the gels. Furthermore, we evaluated the effect of therapeutic pulsed ultrasound (TPU) in association with the gel-diosmin complex on the parameters of muscle damage and oxidative stress in rats. Serum creatine kinase (CK) levels were used as an indicator of skeletal muscle injury. Lipid peroxidation (thiobarbituric acid-reactive substances [TBARS]) and superoxide dismutase and catalase activities were used as indicators of oxidative stress. The results obtained indicated that the inclusion complex obtained by co-evaporation had the highest complexation efficiency and stability; there was no change in the features of diosmin on incorporation into the Carbopol gel. Additionally, a significant (p <0.05) decrease was observed in CK levels (TPU plus gel-diosmin: 178.4 ± 85.3 U/L) relative to the untreated group (527.8 ± 46.1 U/L). Levels of TBARS were lower in the TPU plus gel-diosmin group (0.008 ± 0.0004 nmol malondialdehyde/mg protein, p <0.05) compared with the untreated group (0.081 ± 0.011 nmol malondialdehyde/mg protein, p <0.05, n = 6). Catalase activity did not statistically significantly differ between the treatment groups, and superoxide dismutase activity was lower in the diosmin-treated group (0.320 ± 0.11 U/mg protein) compared with the untreated group (0.983 ± 0.40 U/mg protein). These results suggest that TPU in association with the diosmin-gel complex is effective in reducing muscle damage and oxidative stress after mechanical trauma.