Characterization of thymoquinone/hydroxypropyl-β-cyclodextrin inclusion complex: Application to anti-allergy properties

New insights into the influence of encapsulation materials on the feasibility of ultrasonic-assisted encapsulation of Mosla chinensis essential oil

The study aimed to estimate the feasibility of α-cyclodextrin (α-CD), β-cyclodextrin (β-CD), and γ-cyclodextrin (γ-CD) to encapsulate Mosla chinensis essential oil (EO) by ultrasonic-assisted method. The physical properties variations, stabilization mechanisms, and formation processes of the inclusion complexes (ICs) were investigated using experimental methods, molecular docking, and molecular dynamics (MD) simulation. Scanning electron microscopy, fourier transform infrared spectroscopy, thermogravimetric analysis, and gas chromatography-mass spectrometry showed that the ICs were successfully prepared, which differentially improved the thermal stability and retained the chemical composition of EO. The dissolution profile showed that the Peppas model can be used to describe the diffuse release mechanism of EO. Finally, molecular docking and MD simulation theoretically confirmed the interaction and conformational changes of carvacrol (the main active component of Mosla chinensis EO) inside the cavity of CDs. The results indicate that hydrogen bonding was the primary driving force for the carvacrol spontaneous access to the cavity. Further, a binding dynamic balance occurs between carvacrol and β-CD, whereas a bind and away dynamic balance occurs in the IC between carvacrol and α-CD, γ-CD. The comprehensive results show that the medium cavity size of β-CD is a suitable host molecule for Mosla chinensis EO of encapsulation, release, and stabilization. A combination of experimental and theoretical calculations is useful for the pinpoint targeted design and optimization of CD molecular encapsulation of small entity molecules. β-CD was rationally screened as a better candidate for stabilizing EO, which provides an option for a meaningful path to realistic EO applications.

Characteristics, antimicrobial capacity, and antioxidant potential of electrospun zein/polyvinyl alcohol nanofibers containing thymoquinone and electrosprayed resveratrol nanoparticles

The aim of the present study was to fabricate, characterize, and evaluate the in vitro antimicrobial and antioxidant properties of zein/polyvinyl alcohol (ZN/PVA) nanofibers containing 2% and 4% of thymoquinone (TQ), either alone or in combination with electrosprayed ZN nanoparticles containing 1% and 2% of resveratrol (RS). According to scanning electron microscopy analysis, the diameter of nanofibers and nanoparticles increased with increasing TQ and RS concentrations, respectively. The molecular interaction between ZN or PVA polymers and TQ or RS was confirmed by Fourier transform infrared spectroscopy. Thermogravimetric analysis showed that the thermal stability of nanofibers did not change with the addition of TQ and RS. Moreover, incorporation of TQ in nanofibers along with RS nanoparticles increased their antibacterial and free radical scavenging activities based on broth dilution and DPPH methods, respectively (p ≤ .05). Escherichia coli O157:H7 (as a Gram-negative pathogenic bacteria) was more resistant to all treatments than Staphylococcus aureus (as a Gram-positive pathogenic bacteria). In addition, the combined use of TQ in nanofibers and RS nanoparticles had antagonistic antibacterial and synergistic antioxidant effects. The best results were obtained with ZN/PVA nanofiber containing 4% TQ and electrosprayed with 2% RS nanoparticles (p ≤ .05). According to the results of the present study, biodegradable ZN/PVA nanofiber containing TQ and electrosprayed with RS nanoparticles can be used as a novel active packaging material in the food industry.

Mangifera indica L. kernel ethanol extract inhibits cell viability and proliferation with induction of cell cycle arrest and apoptosis in lung cancer cells

In this study, we investigated the effects of an ethanolic extract of Mangifera indica L. kernel on the viability and proliferation of human lung cancer cells. We utilized MTT and BrdU cell proliferation assays, morphological assessments, cell cycle analyses, and apoptosis assays to investigate the extract's effects on lung cancer (A549 and NCI-H292) and normal lung (MRC-5) cells. The extract demonstrated a toxicity toward cancer cells compared to normal cells with dose-dependent anti-proliferative effect on lung cancer cells. The extract also caused differential effects on the cell cycle, inducing G0/G1 arrest and increasing the Sub-G1 population in both lung cancer and normal lung cells. Notably, the extract induced loss of membrane integrity, shrinkage, membrane blebbing, and apoptosis in lung cancer cells, while normal cells exhibited only early apoptosis. Furthermore, the extract exhibited higher toxicity towards NCI-H292 cells, followed by A549 and normal MRC-5 cells in decreasing order of potency. Our results suggest that the ethanolic extract of M. indica L. kernel has significant potential as a novel therapeutic agent for treating lung cancer cells, given its ability to induce apoptosis in cancer cell lines while causing minimal harm to normal cells.

How Thymoquinone from Nigella sativa Accelerates Wound Healing through Multiple Mechanisms and Targets

Wound healing is a multifaceted process necessitating the collaboration of numerous elements to mend damaged tissue. Plant and animal-derived natural compounds have been utilized for wound treatment over the centuries, with many scientific investigations examining these compounds. Those with antioxidant, anti-inflammatory, and antibacterial properties are particularly noteworthy, as they target various wound-healing stages to expedite recovery. Thymoquinone, derived from Nigella sativa (N. sativa)-a medicinal herb with a long history of use in traditional medicine systems such as Unani, Ayurveda, Chinese, and Greco-Arabic and Islamic medicine-has demonstrated a range of therapeutic properties. Thymoquinone exhibits antimicrobial, anti-inflammatory, and antineoplastic activities, positioning it as a potential remedy for skin pathologies. This review examines recent research on how thymoquinone accelerates wound healing and the mechanisms behind its effectiveness. We carried out a comprehensive review of literature and electronic databases, including Google Scholar, PubMed, Science Direct, and MedlinePlus. Our aim was to gather relevant papers published between 2015 and August 2023. The main criteria for inclusion were that the articles had to be peer reviewed, original, written in English, and discuss the wound-healing parameters of thymoquinone in wound repair. Our review focused on the effects of thymoquinone on the cellular and molecular mechanisms involved in wound healing. We also examined the role of cytokines, signal transduction cascades, and clinical trials. We found sufficient evidence to support the effectiveness of thymoquinone in promoting wound healing. However, there is no consensus on the most effective concentrations of these substances. It is therefore essential to determine the optimal treatment doses and the best route of administration. Further research is also needed to investigate potential side effects and the performance of thymoquinone in clinical trials.

HDAC inhibition by Nigella sativa L. sprouts extract in hepatocellular carcinoma: an approach to study anti-cancer potential

A wide variety of natural products have been widely used in chemoprevention therapy because they have antioxidant, anti-inflammatory, and anticancer activity. In the present study, we shed light on the 5th day germinated sprouts of N. sativa seeds and evaluated them against HDAC inhibition and antioxidant activity. The extract from the seed and sprout was extracted and characterised by LC-MS/MS, FTIR, and NMR to reveal its chemical composition, especially thymol (THY) and thymoquinone (TQ). Hepatocellular carcinoma (HCC) is a global health concern as it is a major lifestyle disease. Hence, incorporating herbal-based therapeutic compounds into everyday routines has become an attractive alternative for preventing hepatic diseases. Histone deacetylase (HDAC) inhibition (HDACi) is emerging as a promising therapeutic strategy for managing various carcinomas including HCC. Therefore, the 5th day of N. sativa can be used as a potential anticancer agent by inhibiting HDAC activity, as it is reported to have an important role in the management of oxidative stress. The bioactive compound of N. sativa, i.e. thymoquinone, also showed a good binding affinity with the HDAC protein (3MAX) with a stable interaction in an in silico study as compared to the standard drug (Trichostatin A) and thymol.Communicated by Ramaswamy H. Sarma.

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.

Continuous Manufacturing of Solvent-Free Cyclodextrin Inclusion Complexes for Enhanced Drug Solubility via Hot-Melt Extrusion: A Quality by Design Approach

Conventional cyclodextrin complexation enhances the solubility of poorly soluble drugs but is solvent-intensive and environmentally unfavorable. This study evaluated solvent-free hot-melt extrusion (HME) for forming cyclodextrin inclusion complexes to improve the solubility and dissolution of ibuprofen (IBU). Molecular docking confirmed IBU's hosting in Hydroxypropyl-β-cyclodextrin (HPβ-CD), while phase solubility revealed its complex stoichiometry and stability. In addition, an 11 mm twin-screw co-rotating extruder with PVP VA-64 as an auxiliary substance aided the complex formation and extrusion. Using QbD and the Box-Behnken design, we studied variables (barrel temperature, screw speed, and polymer concentration) and their impact on solubility and dissolution. The high polymer concentration and high screw speeds positively affected the dependent variables. However, higher temperatures had a negative effect. The lowest barrel temperature set near the Tg of the polymer, when combined with high polymer concentrations, resulted in high torques in HME and halted the extrusion process. Therefore, the temperature and polymer concentration should be selected to provide sufficient melt viscosities to aid the complex formation and extrusion process. Studies such as DSC and XRD revealed the amorphous conversion of IBU, while the inclusion complex formation was demonstrated by ATR and NMR studies. The dissolution of ternary inclusion complexes (TIC) produced from HME was found to be ≥85% released within 30 min. This finding implied the high solubility of IBU, according to the US FDA 2018 guidance for highly soluble compounds containing immediate-release solid oral dosage forms. Overall, the studies revealed the effect of various process parameters on the formation of CD inclusion complexes via HME.

Cellular, Molecular, Pharmacological, and Nano-Formulation Aspects of Thymoquinone-A Potent Natural Antiviral Agent

The goal of an antiviral agent research is to find an antiviral drug that reduces viral growth without harming healthy cells. Transformations of the virus, new viral strain developments, the resistance of viral pathogens, and side effects are the current challenges in terms of discovering antiviral drugs. The time has come and it is now essential to discover a natural antiviral agent that has the potential to destroy viruses without causing resistance or other unintended side effects. The pharmacological potency of thymoquinone (TQ) against different communicable and non-communicable diseases has been proven by various studies, and TQ is considered to be a safe antiviral substitute. Adjunctive immunomodulatory effects in addition to the antiviral potency of TQ makes it a major compound against viral infection through modulating the production of nitric oxide and reactive oxygen species, decreasing the cytokine storm, and inhibiting endothelial dysfunction. Nevertheless, TQ's low oral bioavailability, short half-life, poor water solubility, and conventional formulation are barriers to achieving its optimal pharmacologic benefits. Nano-formulation proposes numerous ways to overcome these obstacles through a small particle size, a big surface area, and a variety of surface modifications. Nano-based pharmaceutical innovations to combat viral infections using TQ are a promising approach to treating surmounting viral infections.

Fabrication and Characterization of β-Cyclodextrin/Mosla Chinensis Essential Oil Inclusion Complexes: Experimental Design and Molecular Modeling

Essential oils (EOs) are primarily isolated from medicinal plants and possess various biological properties. However, their low water solubility and volatility substantially limit their application potential. Therefore, the aim of the current study was to improve the solubility and stability of the Mosla Chinensis (M. Chinensis) EO by forming an inclusion complex (IC) with β-cyclodextrin (β-CD). Furthermore, the IC formation process was investigated using experimental techniques and molecular modeling. The major components of M. Chinensis 'Jiangxiangru' EOs were carvacrol, thymol, o-cymene, and terpinene, and its IC with β-CD were prepared using the ultrasonication method. Multivariable optimization was studied using a Plackett-Burman design (step 1, identifying key parameters) followed by a central composite design for optimization of the parameters (step 2, optimizing the key parameters). SEM, FT-IR, TGA, and dissolution experiments were performed to analyze the physicochemical properties of the ICs. In addition, the interaction between EO and β-CD was further investigated using phase solubility, molecular docking, and molecular simulation studies. The results showed that the optimal encapsulation efficiency and loading capacity of EO in the ICs were 86.17% and 8.92%, respectively. Results of physicochemical properties were different after being encapsulated, indicating that the ICs had been successfully fabricated. Additionally, molecular docking and dynamics simulation showed that β-CD could encapsulate the EO component (carvacrol) via noncovalent interactions. In conclusion, a comprehensive methodology was developed for determining key parameters under multivariate conditions by utilizing two-step optimization experiments to obtain ICs of EO with β-CD. Furthermore, molecular modeling was used to study the mechanisms involved in molecular inclusion complexation.

Thymoquinone: Hydroxypropyl-β-cyclodextrin Loaded Bacterial Cellulose for the Management of Wounds

The need for more advantageous and pharmaceutically active wound dressings is a pressing matter in the area of wound management. In this study, we explore the possibility of incorporating thymoquinone within bacterial cellulose, utilising cyclodextrins as a novel method of solubilising hydrophobic compounds. The thymoquinone was not soluble in water, so was incorporated within hydroxypropyl-β-cyclodextrin before use. Thymoquinone: hydroxypropyl-β-cyclodextrin inclusion complex produced was found to be soluble in water up to 7% (w/v) and was stable with no crystal formation for at least 7 days with the ability to be loaded within the bacterial cellulose matrix. The inclusion complex was found to be thermally stable up to 280 °C which is far greater than the production temperature of 80 °C and was stable in phosphate-buffered saline and extraction solvents in permeation and dose experiments. The adhesion properties of the Thymoquinone: hydroxypropyl-β-cyclodextrin loaded bacterial cellulose dressings were tested and found to be 2.09 N. Permeation studies on skin mimicking membrane Strat-M showed a total permeated amount (0-24 h) of 538.8 µg cm^-2 and average flux after a 2 h lag of 22.4 µg h^-1 cm^-2. To the best of our knowledge, the methods outlined in this study are the first instance of loading bacterial cellulose with thymoquinone inclusion complex with the aim of producing a pharmaceutically active wound dressing.

Ternary Inclusion Complex of Sinapic Acid with Hydroxypropyl-β-cyclodextrin and Hydrophilic Polymer Prepared by Microwave Technology

Sinapic acid (SA) is a poorly water-soluble substance which could result in poor bioavailability. The aim of this study was to determine the “hydroxypropyl β-cyclodextrin (HPβCD)” solubilization of SA in the presence of the auxiliary substance hydroxypropyl methylcellulose (HPMC) and to evaluate the ternary inclusion complex prepared by microwave technology. Phase-solubility profiles showed that HPβCD exhibited the greatest solubilizing effect on SA in the presence of HPMC. The enhanced rate of SA dissolution was exhibited by a ternary complex. Outcomes of analyses such as “DSC, FTIR, NMR, and SEM” confirmed the embedding of SA into the cavity of the HPβCD and the formation of a ternary inclusion complex. The outcomes of antioxidant activity (ABTS and nitric oxide scavenging activity) demonstrated that SA ternary inclusion complex (TIC) presented strong antioxidant activity, which might be a result of the enhanced solubility of SA in the TIC prepared by microwave technology. Hence, SA-TIC formulation could be a better dosage form which may protect the body from free radical damage and oxidative stress. Microwave technology greatly boosted the interaction of SA with HPβCD and HPMC, and such findings are expected to contribute to raising the solubility of SA, thereby improving the bioavailability of SA.

Development and Evaluation of Amlodipine-Polymer Nanocomposites Using Response Surface Methodology

Introduction. Polymer nanoparticles are a key tool to deliver drugs to specific sites and to increase drug bioavailability. Aim. This research aims to use poly amide-disulfide nanoparticles as drug delivery systems. Method. Amlodipine (Amlop) was used as a model, forming Amlop-polymer nanocomposites. In this work, we investigated the effect of independent variables (polymer, Fe3+, Al3+, and pH) on the dependent variables (loading efficiency (%LE), zeta potential, and particle size). Nanocomposites were prepared by an inotropic method. Nanocomposites were characterized by powder X-ray diffraction (PXRD), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR), and a release study. Results. From the XRD data, the Amlop-polymer nanocomposite shows semi crystallinity. In addition, the disappearance of drug peaks indicates that the drug was incorporated between the polymer molecules and was amorphous in behavior. The FTIR for the nanocomposite shows the functional group of the drug, which indicates the incorporation of Amlop into the nanocomposite. From FE-SEM, the results showed that our nanocomposites have an average particle size of approximately 130 nm. The release of amlodipine from the Amlop-polymer nanocomposite was found to be controlled, with approximately 85% within approximately 24 hours. Conclusion. The amide-disulfide polymer nanoparticles are promising carriers for different types of drugs.

Quercetin/Hydroxypropyl-β-Cyclodextrin Inclusion Complex-Loaded Hydrogels for Accelerated Wound Healing

This study concentrated on developing quercetin/cyclodextrin inclusion complex-loaded polyvinyl alcohol (PVA) hydrogel for enhanced stability and solubility. Quercetin was encapsulated in hydroxypropyl-β-cyclodextrin (HP-β-CD) by the solvent evaporation method. The prepared quercetin/HP-β-CD inclusion complex showed 90.50 ± 1.84% encapsulation efficiency (%EE) and 4.67 ± 0.13% loading capacity (%LC), and its successful encapsulation was confirmed by FT-IR and XRD. The quercetin/HP-β-CD inclusion complex was well dispersed in viscous solutions of PVA in various amounts (0.5, 1.0, 1.5. 2.5, and 5.0% w/v ratio), and the drug-loaded polymer solution was physically crosslinked by multiple freeze–thaw cycles to form the hydrogel. The cumulative amount of quercetin released from the prepared hydrogels increased with increasing concentrations of the inclusion complex. The introduction of the inclusion complex into the PVA hydrogels had no influence on their swelling ratio, but gelation and compressive strength reduced with increasing inclusion complex concentration. The potential cytotoxicity of quercetin/HP-β-CD inclusion complex hydrogels was evaluated by MTT assay and expressed as % cell viability. The results show biocompatibility toward NCTC 929 clone cells. The inhibitory efficacy was evaluated with 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay, and the results show a higher level of antioxidant activity for quercetin/HP-β-CD inclusion complex hydrogels compared with free quercetin. The findings of our study indicate that the developed quercetin/HP-β-CD inclusion complex hydrogels possess the required properties and can be proposed as a quercetin delivery system for wound-healing applications.

The effects of thymoquinone on pancreatic cancer: Evidence from preclinical studies

Thymoquinone (TQ) is a secondary metabolite found in abundance in very few plant species including Nigella sativa L., Monarda fistulosa L., Thymus vulgaris L. and Satureja montana L. Preclinical pharmacological studies have shown that TQ has many biological activities, such as anti-inflammatory, antioxidant and anticancer. Both in vivo and in vitro experiments have shown that TQ acts as an antitumor agent by altering cell cycle progression, inhibiting cell proliferation, stimulating apoptosis, inhibiting angiogenesis, reducing metastasis and affecting autophagy. In this comprehensive study, the evidence on the pharmacological potential of TQ on pancreatic cancer is reviewed. The positive results of preclinical studies support the view that TQ can be considered as an additional therapeutic agent against pancreatic cancer. The possibilities of success for this compound in human medicine should be further explored through clinical trials.

Developing Novel Hydroxypropyl-β-Cyclodextrin-Based Nanosponges as Carriers for Anticancer Hydrophobic Agents: Overcoming Limitations of Host–Guest Complexes in a Comparative Evaluation

This study aimed to design and fabricate novel hydroxypropyl-β-cyclodextrin-based hypercrosslinked polymers, called nanosponges, as carriers for anticancer hydrophobic agents and compare them with host–guest complexes of hydroxypropyl-β-cyclodextrin, a remarkable solubilizer, to investigate their application in improving the pharmaceutical properties of the flavonoid naringenin, a model hydrophobic nutraceutical with versatile anticancer effects. For this purpose, three new nanosponges, crosslinked with pyromellitic dianhydride, citric acid, and carbonyldiimidazole, were fabricated. The carbonate nanosponge synthesized by carbonyldiimidazole presented the highest naringenin loading capacity (≈19.42%) and exerted significantly higher antiproliferative effects against MCF-7 cancer cells compared to free naringenin. Additionally, this carbonate nanosponge formed a stable nanosuspension, providing several advantages over the naringenin/hydroxypropyl-β-cyclodextrin host–guest complex, including an increase of about 3.62-fold in the loading capacity percentage, sustained released pattern (versus the burst pattern of host–guest complex), and up to an 8.3-fold increase in antiproliferative effects against MCF-7 cancer cells. Both naringenin-loaded carriers were less toxic to L929 murine fibroblast normal cells than MCF-7 cancer cells. These findings suggest that hydroxypropyl-β-cyclodextrin-based carbonate nanosponges could be a good candidate as a drug delivery system with potential applications in cancer treatment.

Complexation of phytochemicals with cyclodextrins and their derivatives- an update

Bioactive phytochemicals from natural source have gained tremendous interest over several decades due to their wide and diverse therapeutic activities playing key role as functional food supplements, pharmaceutical and nutraceutical products. Nevertheless, their application as therapeutically active moieties and formulation into novel drug delivery systems are hindered due to major drawbacks such as poor solubility, bioavailability and dissolution rate and instability contributing to reduction in bioactivity. These drawbacks can be effectively overcome by their complexation with different cyclodextrins. Present article discusses complexation of phytochemicals varying from flavonoids, phenolics, triterpenes, and tropolone with different natural and synthetic cyclodextrins. Moreover, the article summarizes complexation methods, complexation efficiency, stability, stability constants and enhancement in rate and extent of dissolution, bioavailability, solubility, in vivo and in vitro activities of reported complexed phytochemicals. Additionally, the article presents update of published patent details comprising of complexed phytochemicals of therapeutic significance. Thus, phytochemical cyclodextrin complexes have tremendous potential for transformation into drug delivery systems as substantiated by significant outcome of research findings.

Preparation, characterization, in vitro drug release and anti-inflammatory of thymoquinone-loaded chitosan nanocomposite

In this study, we formulated Thymoquinone-loaded nanocomposites (TQ-NCs) using high-pressure homogenizer without sodium tripolyphosphate. The TQ-NCs were characterized and their anti-inflammatory determined by the response of the LPS-stimulated macrophage RAW 264.7 cells in the production of nitric oxide, prostaglandin E2, tumor necrosis factor-α, interleukin-6, and interleukin-1β. The physicochemical properties of TQ-NC were determined using different machines. TQ was fully incorporated in the highly thermal stable nanoparticles. The nanoparticles showed rapid release of TQ in the acidic medium of the gastric juice. In medium of pH 6.8, TQ-NC exhibited sustained release of TQ over a period of 100 h. The results suggest that TQ-NC nanoparticles have potential application as parenterally administered therapeutic compound. TQ-NC effectively reduce production of inflammatory cytokines by the LPS-stimulated RAW 264.7 cells, indicating that they have anti-inflammatory properties. In conclusion, TQ-NC nanoparticles have the characteristics of efficient carrier for TQ and an effective anti-inflammatory therapeutic compound.

Preparation, characterization, and biological activity study of thymoquinone-cucurbit[7]uril inclusion complex

In this study, the formation of a host–guest inclusion complex between cucurbit[7]uril (CB[7]) and thymoquinone (TQ) was investigated in aqueous solution. The formation of a stable inclusion complex, CB[7]–TQ, was confirmed by using different techniques, such as ¹H NMR and UV-visible spectroscopy. The aqueous solubility of TQ was clearly enhanced upon the addition of CB[7], which provided an initial indication for supramolecular complexation. The complexation stoichiometry and the binding constant of the inclusion complex were determined through a combination of two sets of titration methods, including UV-visible and fluorescence displacement titrations. Both methods suggested the formation of a 1 : 1 stoichiometry between CB[7] and TQ with moderate binding affinity of 3 × 10³ M⁻¹. Density functional theory (DFT) calculations were also performed to verify the structure of the resulted host–guest complex and to support the complexation stoichiometry. The theoretical calculations were in agreement with experimental results obtained by ¹H NMR spectroscopy. Most importantly, the cytotoxic effect of the CB[7]–TQ complex was investigated against cancer and normal cell lines. The results showed that the anticancer activity of TQ against MDA-MB-231 cells was enhanced by the complexation with CB[7], while no significant effect was observed in MCF-7 cells. The results also confirmed the low toxicity of the CB[7] host molecule that supports the use of CB[7] as a drug carrier.

The host–guest inclusion complexation of thymoquinone by cucurbit[7]uril in aqueous solution is established, which results in an enhanced biological activity.

Improving the solubility of vorinostat using cyclodextrin inclusion complexes: The physicochemical characteristics, corneal permeability and ocular pharmacokinetics of the drug after topical application

Vorinostat (suberoylanilide hydroxamic acid, SAHA), an FDA-approved drug for cutaneous T cell lymphoma, has antiangiogenic and anti-inflammatory activity and thus has therapeutic potential for inflammatory corneal neovascularization (CNV). However, its practical administration is limited due to its poor aqueous solubility and permeability. This study aimed to enhance the corneal permeability of SAHA by promoting its inclusion into a complex with hydroxypropyl-β-CD (HPβCD) for topical application. In phase-solubility studies, the solubility of SAHA with HPβCD and sulfobutyl ether-β-CD (SEβCD) was assessed at different temperatures, and complexation efficiencies (K) were calculated. The inclusion complexes (ICs) were prepared and characterized by differential scanning calorimetry (DSC), infrared spectrometry (IR), scanning electron microscopy (SEM), and X-ray diffraction (XRD) after freeze-drying. The phase-solubility study showed that the complexation efficiencies of SAHA were higher in HPβCD solutions (297.35 M^-1, 115.28 M^-1 and 122.75 M^-1) than in SEβCD solutions (169.75 M^-1, 91.33 M^-1 and 96.49 M^-1) at 4 °C, 25 °C and 37 °C. HPβCD was selected for SAHA-IC preparation, and characterization revealed IC formation. SAHA existed in an amorphous state in the ICs. The ex vivo corneal permeability of SAHA was also evaluated and found to be greater when formulated as an HPβCD solution than as a suspension. Irritation assays in rabbit eyes showed that the SAHA-IC solution was not irritating after topical application. The ocular pharmacokinetics of SAHA in New Zealand White rabbits were assessed following topical administration (0.2%), and a 0.2% SAHA suspension was used as the control. Compared to its formulation as a suspension, the formulation of SAHA as an HPβCD solution increased its corneal bioavailability by more than 3-fold and its conjunctival bioavailability by more than 2-fold. Thus, IC formation was effective at improving the ocular bioavailability of SAHA. This study provides an important alternative approach for developing liquid pharmaceutical formulations of SAHA for topical ocular applications.

Triangulating the pharmacological properties of thymoquinone in regulating reactive oxygen species, inflammation, and cancer: Therapeutic applications and mechanistic pathways

Cancer is a heterogeneous disease with high morbidity and mortality rate involving changes in redox balance and deregulation of redox signalling. For decades, studies have involved developing an effective cancer treatment to combat treatment resistance. As natural products such as thymoquinone have numerous health benefits, studies are also focusing on using them as a viable method for cancer treatment, as they have minimal toxic effects compared with standard cancer treatments. Thymoquinone studies have shown numerous mechanisms of action, such as regulation of reactive species interfering with DNA structure, modulating various potential targets and their signalling pathways as well as immunomodulatory effects in vitro and in vivo. Thymoquinone's anti-cancer effect is mainly due to the induction of apoptotic mechanisms, such as activation of caspases, downregulation of precancerous genes, inhibition of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), anti-tumour cell proliferation, ROS regulation, hypoxia and anti-metastasis. Insight into thymoquinone's potential as an alternative treatment for chemoprevention and inflammation can be accomplished via compiling these studies, to provide a better understanding on how and why it works, as well as its interactions with common chemotherapeutic treatments.

Inclusion complexation of the anticancer drug pomalidomide with cyclodextrins: fast dissolution and improved solubility

Pomalidomide (POM), a potent anticancer thalidomide analogue was characterized in terms of cyclodextrin complexation to improve its aqueous solubility and maintain its anti-angiogenic activity. The most promising cyclodextrin derivatives were selected by phase-solubility studies. From the investigated nine cyclodextrins - differing in cavity size, nature of substituents, degree of substitution and charge - the highest solubility increase was observed with sulfobutylether-β-cyclodextrin (SBE-β-CD). The inclusion complexation between POM and SBE-β-CD was further characterized with a wide variety of state-of-the-art analytical techniques, such as nuclear magnetic resonance spectroscopy (NMR), infrared spectroscopy (IR), circular dichroism spectroscopy, fluorescence spectroscopy as well as X-ray powder diffraction method (XRD). Job plot titration by NMR and the A_L-type phase-solubility diagram indicated 1:1 stoichiometry in a liquid state. Complementary analytical methods were employed for the determination of the stability constant of the complex; the advantages and disadvantages of the different approaches are also discussed. Inclusion complex formation was also assessed by molecular modelling study. Solid state complexation in a 1:1 M ratio was carried out by lyophilization and investigated by IR and XRD. The complex exhibited fast-dissolution with immediate release of POM, when compared to the pure drug at acidic and neutral pH. Kinetic analysis of POM release from lyophilized complex shows that Korsmeyer-Peppas and Weibull model described the best the dissolution kinetics. The cytotoxicity of the complex was tested against the LP-1 human myeloma cell line which revealed that supramolecular interactions did not significantly affect the anti-cancer activity of the drug. Overall, our results suggest that the inclusion complexation of POM with SBE-β-CD could be a promising approach for developing more effective POM formulations with increased solubility.

Thymoquinone Loaded Topical Nanoemulgel for Wound Healing: Formulation Design and In-Vivo Evaluation

Thymoquinone is a natural bioactive with significant therapeutic activity against multiple ailments including wound healing. The poor aqueous solubility and low skin permeability limit its therapeutic efficacy. The present investigation aimed to improve the biopharmaceutical attributes of thymoquinone to enhance its topical efficacy in wound healing. A nanoemulsion-based hydrogel system was designed and characterized as a nanotechnology-mediated drug delivery approach to improve the therapeutic efficacy of thymoquinone, utilizing a high-energy emulsification technique. The black seed oil, as a natural home of thymoquinone, was utilized to improve the drug loading capacity of the developed nanoemulsion system and reduced the oil droplet size to <100 nm through ultrasonication. The influence of formulation composition, and the ultrasonication process conditions, were investigated on the mean globule size and polydispersity index of the generated nanoemulsion. Irrespective of surfactant/co-surfactant ratio and % concentration of surfactant/co-surfactant mixture, the ultrasonication time had a significant (p < 0.05) influence on the mean droplet size and polydispersity index of the generated nanoemulsion. The developed nanoemulgel system of thymoquinone demonstrated the pseudoplastic behavior with thixotropic properties, and this behavior is desirable for topical application. The nanoemulgel system of thymoquinone exhibited significant enhancement (p < 0.05) in skin penetrability and deposition characteristics after topical administration compared to the conventional hydrogel system. The developed nanoemulgel system of thymoquinone exhibited quicker and early healing in wounded Wistar rats compared to the conventional hydrogel of thymoquinone, while showing comparable healing efficacy with respect to marketed silver sulfadiazine (1%) cream. Furthermore, histopathology analysis of animals treated with a developed formulation system demonstrated the formation of the thick epidermal layer, papillary dermis along with the presence of extensive and organized collagen fibers in newly healed tissues. The outcome of this investigation signifies that topical delivery of thymoquinone through nanoemulgel system is a promising candidate which accelerates the process of wound healing in preclinical study.

Oxidative stress cytotoxicity induced by platinum-doped magnesia nanoparticles in cancer cells

The aim of this study was to prepare, characterize, and determine the in vitro anticancer effects of platinum-doped magnesia (Pt/MgO) nanoparticles. The chemical compositions, functional groups, and size of nanoparticles were determined using X-ray diffraction, Fourier transform infrared spectroscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, and scanning electron microscopy. Pt/MgO nanoparticles were cuboid and in the nanosize range of 30-50 nm. The cytotoxicity of Pt/MgO nanoparticles was determined via the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay on the human lung and colonic cancer cells (A549 and HT29 respectively) and normal human lung and colonic fibroblasts cells (MRC-5 and CCD-18Co repectively). The Pt/MgO nanoparticles were relatively innocuous to normal cells. Pt/MgO nanoparticles downregulated Bcl-2 and upregulated Bax and p53 tumor suppressor proteins in the cancer cells. Pt/MgO nanoparticles also induced production of reactive oxygen species, decreased cellular glutathione level, and increased lipid peroxidation. Thus, the anticancer effects of Pt/MgO nanoparticles were attributed to the induction of oxidative stress and apoptosis. The study showed the potential of Pt/MgO nanoparticles as an anti-cancer compound.

Inclusion complex of clausenidin with hydroxypropyl-β-cyclodextrin: Improved physicochemical properties and anti-colon cancer activity

The long-term objective of the present study was to prepare, physicochemically characterize and determine the anticancer of clausenidin/hydroxypropyl-β-cyclodextrin (Clu/HPβCD) inclusion complex. We used differential scanning calorimetry, X-ray diffractometer, fourier transform infrared spectroscopy, ultraviolet–visible spectrophotometer and ¹³C and ¹H nuclear magnetic resonance followed by in vitro anticancer assays. The orientation and intermolecular interactions of Clausenidin within cyclodextrin cavity were also ascertained by molecular docking simulation accomplished by AutoDock Vina. The guest molecule was welcomed by the hydrophobic cavity of the host molecule and sustained by hydrogen bond between host/guest molecules. The constant drug release with time, and increased solubility were found after successful complexation with HPβCD as confirmed by physicochemical characterizations. Clausenidin had greater cytotoxic effect on colon cancer HT29 cells when incorporated into HPβCD cavity than dissolved in DMSO. Also, from a comparison of cell viability between normal and cancer cells, a reduced side effect was observed. The Clu/HPβCD inclusion complex triggered reactive oxygen species-mediated cytotoxicity in HT29 cells. The inclusion complex-treated HT29 cells showed cell cycle arrest and death by apoptosis associated with caspases activation. The presence of HPβCD seems to aid the anticancer activity of clausenidin.

The effects of Nigella sativa on respiratory, allergic and immunologic disorders, evidence from experimental and clinical studies, a comprehensive and updated review

Nigella sativa (N. sativa) seed had been used traditionally due to several pharmacological effects. The updated experimental and clinical effects of N. sativa and its constituents on respiratory, allergic and immunologic disorders are provided in this comprehensive review article. Various databases including PubMed, Science Direct and Scopus were used. The preventive effects of N. sativa on pulmonary diseases were mainly due to its constituents such as thymoquinone, thymol, carvacrol and alpha-hederin. Extracts and constituents of N. sativa showed the relaxant effect, with possible mechanisms indicating its bronchodilatory effect in obstructive pulmonary diseases. In experimental animal models of different respiratory diseases, the preventive effect of various extracts and constituents of N. sativa was demonstrated by mechanisms such as antioxidant, immunomodulatory and antiinflammatory effects. Bronchodilatory and preventive effects of the plant and its components on asthma, COPD and lung disorders due to exposure to noxious agents as well as on allergic and immunologic disorders were also shown in the clinical studies. Various extracts and constituents of N. sativa showed pharmacological and therapeutic effects on respiratory, allergic and immunologic disorders indicating possible remedy effect of that the plant and its effective substances in treating respiratory, allergic and immunologic diseases.

Synergetic effects of thymoquinone-loaded porous PVPylated Fe3O4 nanostructures for efficient pH-dependent drug release and anticancer potential against triple-negative cancer cells

Porous iron oxide nanostructures have attracted increasing attention due to their potential biomedical applications as nanocarriers for cancer and many other therapies as well as minimal toxicity. Herbal anti-cancer agent thymoquinone loaded on Fe₃O₄ nanoparticles is envisaged to offer solution towards cancer treatment. The purpose of the present study was to investigate the efficacy of thymoquinone-loaded PVPylated Fe₃O₄ magnetic nanoparticles (TQ-PVP-Fe₃O₄ NPs) against triple-negative breast cancer (TNBC) cells. The porous PVPylated Fe₃O₄ NPs were prepared by a simple solvothermal process, whereas the thymoquinone drug was loaded via the nanoprecipitation method. Fourier transform infrared (FTIR) spectroscopic analysis confirmed the molecular drug loading, and surface morphological observation further confirmed this. The quantity of thymoquinone adsorbed onto the porous PVPylated Fe₃O₄ NPs was studied by thermogravimetric analysis (TGA). The positive surface charge of TQ-PVP-Fe₃O₄ NPs facilitates the interaction of the NPs with cancer (MDA-MB-231) cells to enhance the biological functions. In addition, the anticancer potential of NPs involving cytotoxicity, apoptosis induction, reactive oxygen species (ROS) generation, and changes in the mitochondrial membrane potential (ΔΨ _m) of TNBC cells was evaluated. TQ-PVP-Fe₃O₄ NP-treated cells effectively increased the ROS levels leading to cellular apoptosis. The study shows that the synthesized TQ-PVP-Fe₃O₄ NPs display pH-dependent drug release in the cellular environment to induce apoptosis-related cell death in TNBC cells. Hence, the prepared TQ-PVP-Fe₃O₄ NPs may be a suitable drug formulation for anticancer therapy.

Release Characteristics of an Essential Oil Component Encapsulated with Cyclodextrin Shell Matrices

BACKGROUND

Essential oils are poor aqueous solubility and high volatility compounds. The encapsulation of essential oils with Cyclodextrins (CDs) can protect them from adverse environmental conditions and improve their stability. Therefore, increasing the functional capabilities of essential oils when they were used as additives in pharmaceutical and food systems. Additionally, the release of active compounds is an important issue. However, there were few studies about the effect of different CDs on the release of drugs after encapsulation. Therefore, the information on the study of release models is considerably limited.

OBJECTIVE

This study aimed to (i) characterize the physico-chemical properties and release behavior of myrcene encapsulated in the four different shell matrices of α-CD, β-CD, γ-CD and 2-hydroxypropyl-β- cyclodextrin (HP-β-CD), which were selected from the perspective of stability, and (ii) determine the release mechanism of myrcene in Inclusion Complexes (ICs).

METHODS

ICs of myrcene and four CDs were prepared by freeze-drying. The physico-chemical properties of ICs were fully characterized by laser diffraction particle size analyzer, Scanning Electron Microscope (SEM), Fourier-Transform Infrared spectroscopy (FT-IR) and Differential Scanning Calorimeter (DSC). The release behaviors of ICs at 50, 60, 70 and 80 °C were determined and described by zeroorder or first-order kinetics with the Henderson-Pabis, Peppas, Avrami and Page mathematical models. Moreover, the possible binding modes of ICs were identified with molecular modelling technique.

RESULTS

Firstly, the structure of Particle Size Distribution (PSD), FT-IR, DSC and SEM showed that (i) CDs could effectively encapsulate the myrcene molecules, and (ii) the release kinetics were well simulated by Avrami and Page models. Secondly, the release rates of the ICs experienced an unsteady state in the early stage, and gradually became almost constants period after 20 hours. Except that the release of myrcene in γ-CD/myrcene belonged to the first-order kinetic, the release models of the remaining three ICs belonged to diffusion mode. Thirdly, the calculated binding energies of the optimized structures for α-CD/myrcene, β-CD/myrcene, γ-CD/myrcene, and HP-β-CD/myrcene ICs were -4.28, -3.82, -4.04, and -3.72 kcal/mol, respectively. Finally, the encapsulation of myrcene with α-CD and β-CD was preferable according to the stability and release characteristics.

CONCLUSION

The encapsulation of myrcene was profoundly affected by the type of CDs, and the stability could be improved by complexation with suitable CDs. The binding behavior between guest and CD molecules, and the release profile of the guest molecules could be effectively explained by the kinetics parameters and molecular modelling. This study can provide an effective basis and guide for screening suitable shell matrices.

Pterostilbene complexed with cyclodextrin exerts antimicrobial and anti-inflammatory effects

Resveratrol (RES) is a natural polyphenol with potential as an adjunctive therapeutic modality for periodontitis. However, its inferior pharmacokinetics and toxicity concerns about its commonly used solvent dimethyl sulfoxide (DMSO) hinder translation to clinical applicability. Our study aimed to investigate the comparative antimicrobial properties of RES and its analogues (pterostilbene [PTS], oxyresveratrol [OXY] and piceatannol [PIC]), utilizing 2-hydroxypropyl-β-cyclodextrin (HPβCD) as a solubiliser, which has a well-documented safety profile and FDA approval. These properties were investigated against Fusobacterium nucleatum, a key periodontal pathogen. PTS demonstrated the most potent antibacterial effects in HPβCD, with MIC > 60-fold lower than that of RES, OXY and PIC. In addition, PTS inhibited F. nucleatum biofilm formation. PTS exerted antimicrobial effects by eliciting leakage of cellular contents, leading to loss of bacterial cell viability. PTS also conferred immunomodulatory effects on F. nucleatum-challenged macrophages via upregulation of antioxidant pathways and inhibition of NF-κB activation. Given the superior antimicrobial potency of PTS against F. nucleatum compared to RES and other analogues, and coupled with its immunomodulatory properties, PTS complexed with HPβCD holds promise as a candidate nutraceutical for the adjunctive treatment of periodontitis.

Hydroxypropyl-β-Cyclodextrin Complexes of Styryllactones Enhance the Anti-Tumor Effect in SW1116 Cell Line

Styryllactones, a class of compounds obtained from the genus Goniothalamus (Annonaceae), have demonstrated in vitro antitumor activity. However, the aqueous solubility of these compounds is poor. In this study, we identified the absolute configurations of the previously isolated compounds, which were first isolated in our laboratory, by single-crystal X-ray diffraction analysis using Cu Kα radiation. Subsequently, the antitumor activities of the compounds were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide staining in four tumor cell lines. The induced apoptosis activity of leiocarpin E-7'-Monoacetate was studied by an annexin V fluorescein isothiocyanate/propidium iodide double-staining experiment, and the caspase activity was tested in the SW1116 cell line. The results demonstrated that the antitumor activities of cheliensisin A and goniodiol-7-monoacetate were limited by their poor water solubility. To address this issue, hydroxypropyl-β-cyclodextrin (HP-β-CD) complexes of the compounds were synthesized by the saturated aqueous method. The complexes were then analyzed using a differential scanning calorimeter. The IC₅₀ of cheliensisin A was reduced by 45% and 58% against SW1116 and SMMC-7721 cell lines, respectively. Similarly, the IC₅₀ of goniodiol-7-monoacetate was reduced by 55% and 34% against the two tumor cell lines, respectively. To further evaluate whether the styryllactones and complexes possessed selectivity against cancer cell lines and normal cell lines, toxicity against human normal cell line (HEK293T) was evaluated. The results demonstrated that the HP-β-CD complexes displayed more cytotoxicity than the respective pristine compounds against the HEK293T cell line. However, there existed a therapeutic window when the complexes were applied against cancer cell lines. In summary, the synthesis of several styryllactone compounds complexed with HP-β-CD was reported for the first time. These complexes could significantly enhance the cytotoxic effects of styryllactone compounds.

Thymoquinone Glucuronide Conjugated Magnetic Nanoparticle for Bimodal Imaging and Treatment of Cancer as a Novel Theranostic Platform

BACKGROUND

Theranostic oncology combines therapy and diagnosis and is a new field of medicine that specifically targets the disease by using targeted molecules to destroy the cancerous cells without damaging the surrounding healthy tissues.

OBJECTIVE

We aimed to develop a tool that exploits enzymatic TQ release from glucuronide (G) for the imaging and treatment of lung cancer. We added magnetic nanoparticles (MNP) to enable magnetic hyperthermia and MRI, as well as 131I to enable SPECT imaging and radionuclide therapy.

METHODS

A glucuronide derivative of thymoquinone (TQG) was enzymatically synthesized and conjugated with the synthesized MNP and then radioiodinated with 131I. New Zealand white rabbits were used in SPECT and MRI studies, while tumor modeling studies were performed on 6-7- week-old nude mice utilized with bioluminescence imaging.

RESULTS

Fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) spectra confirmed the expected structures of TQG. The dimensions of nanoparticles were below 10 nm and they had rather polyhedral shapes. Nanoparticles were radioiodinated with 131I with over 95% yield. In imaging studies, in xenograft models, tumor volume was significantly reduced in TQGMNP-treated mice but not in non-treated mice. Among mice treated intravenously with TQGMNP, xenograft tumor models disappeared after 10 and 15 days, respectively.

CONCLUSION

Our findings suggest that TQGMNP in solid, semi-solid and liquid formulations can be developed using different radiolabeling nuclides for applications in multimodality imaging (SPECT and MRI). By altering the characteristics of radionuclides, TQGMNP may ultimately be used not only for diagnosis but also for the treatment of various cancers as an in vitro diagnostic kit for the diagnosis of beta glucuronidase-rich cancers.

Anticancer palladium-doped magnesia nanoparticles: synthesis, characterization, and in vitro study

Aim: To prepare, physicochemically characterize and determine the anticancer effects of palladium-doped magnesia (Pd/MgO) nanoparticles. Materials & methods: Pd/MgO nanoparticles were prepared by the co-precipitation method from the aqueous solution of Mg(NO₃)₂.6H₂O using K₂CO₃ and the impregnation of MgO into palladium acetylacetonate. Results: Pd/MgO nanoparticles were between 47 and 70 nm in size, cuboid in shape, and tended to form aggregates. Nanoparticles were more antiproliferative toward cancer than the normal cells. In cancer cells, Pd/MgO nanoparticles induced apoptosis by increasing caspase activities and stimulating cytochrome C release. The anticancer effects of Pd/MgO nanoparticles were accentuated by the upregulation of Bax and p53 and downregulation of Bcl-2 protein expressions. Conclusion: Pd/MgO nanoparticles have potential to be developed as an anticancer compound.