Complexation of phytochemicals with cyclodextrins and their derivatives- an update

Co-crystallization of curcumin with tyramine resulted disparate impacts on the activities of photodynamic and sonodynamic treatments

Curcumin, a plant-derived phenolic compound, has emerged as a promising photo/sonosensitizer within food industry. However, the low aqueous solubility greatly restricts its practical application. Here, we utilized co-crystallization strategy to develop a curcumin-tyramine cocrystal with enhanced solubility (98.53-fold increase over curcumin) and characterized its physicochemical properties using FT-IR, SEM, and XRD. Moreover, the results also showed curcumin-tyramine cocrystal maintained comparable antimicrobial photodynamic activity to that of curcumin (2.44 ± 0.36 vs 3.24 ± 0.42-log decrease in CFU/mL); however, its sonodynamic inactivation efficacy was marked diminished (only exhibiting a 0.46 ± 0.11-log reduction in CFU/mL), suggesting co-crystallization may resulted disparate impacts on activities of photodynamic and sonodynamic treatments. Considering high penetrative ability of ultrasound to activate sensitizers within foods often gives sono/photodynamic treatment an edge over photodynamic treatment alone in food sterilization, our findings suggested the potential imbalanced influence of modification process on photodynamic and sonodynamic activities of sensitizers should not be overlooked when modifying the sensitizers.

Advancements in Cyclodextrin Complexes with Bioactive Secondary Metabolites and Their Pharmaceutical Applications

Cyclodextrins (CDs) have largely been investigated during the last decades for their outstanding properties, such as biocompatibility and biodegradability, with wide applications in the pharmaceutical field, among which the formation of inclusion complexes (ICs) with natural or synthetic lipophilic compounds. This review prioritizes the research of recent years (2022-2025), being focused on (1) systematization of the research of ICs based on the structure of the secondary metabolite, namely (i) polyphenols (PPs), (ii) terpenes and terpenoids (TTs), and (iii) alkaloids (Alks); (2) for each type of inclusion complex, the following aspects have been discussed: benefits of complexation, composite materials, and in vitro/in vivo and theoretical studies; and (3) pharmacokinetics and pharmacodynamics, risks, limitations, and perspectives of cyclodextrin inclusion complexes with secondary metabolites.

Flavonoids regulating NLRP3 inflammasome: a promising approach in alleviating diabetic peripheral neuropathy

A common and serious side effect of diabetes is diabetic peripheral neuropathy (DPN), which is characterised by gradual nerve damage brought on by oxidative stress, chronic inflammation, and prolonged hyperglycemia. Studies identify NLRP3 inflammasome as a key mediator in the pathogenesis of DPN, connecting neuroinflammation and neuronal damage to metabolic failure. Because of their strong anti-inflammatory and antioxidant qualities, flavonoids, a broad class of naturally occurring polyphenols, have drawn interest as potential treatments for DPN. The various ways that flavonoids affect the NLRP3 inflammasome and their potential as a treatment for DPN are examined in this review. It has been demonstrated that flavonoids prevent NLRP3 activation, which lowers the release of pro-inflammatory cytokines including IL-1β and IL-18 and causes neuroinflammation. Flavonoids work mechanistically by reducing oxidative stress, altering important signalling pathways, and blocking the activities of NF-κB and caspase-1, which are both essential for the activation of the NLRP3 inflammasome. Preclinical research has shown that flavonoids have strong neuroprotective benefits, and few clinical evidence also points to the potential of flavonoids to improve nerve function and lessen neuropathic pain in diabetic patients. The current review emphasises how flavonoids may be used as a treatment strategy to target inflammation in DPN caused by the NLRP3 inflammasome. By targeting important inflammatory pathways, flavonoids provide a new way to slow the progression of this debilitating illness. Further investigation into the mechanisms, clinical translation, and novel drug delivery techniques could enhance the therapeutic efficacy of diabetic peripheral neuropathy.

Comparison of the nephroprotective effect of [6]-gingerol and the [6]-gingerol-β-cyclodextrin complex against cisplatin-induced AKI

Cisplatin is an antineoplastic agent effective for the treatment of several cancers. However, due to its nephrotoxicity, its use is limited. Acute kidney injury (AKI) induced by cisplatin is caused by inflammation, apoptosis, and oxidative stress in renal tubular cells. Natural compounds derived from ginger (Zingiber officinale) such as [6]-gingerol, possess anti-inflammatory and antioxidant properties. This study explores the protective effects of [6]-gingerol and its β-cyclodextrin complex ([6]-gingerol-β-CD) on cisplatin-induced AKI in mice. We hypothesize that complexing [6]-gingerol with β-cyclodextrin would enhance its solubility and reduce its pungency, making it more suitable for clinical use. Additionally, we aim to determine whether β-cyclodextrin complexation can improve the oral bioavailability of [6]-gingerol without compromising its therapeutic efficacy. The minimum dose of cisplatin required to induce AKI was determined to be 15 mg/kg. Female Swiss mice (n = 6-8) were divided into four groups: control, cisplatin (15 mg/kg), [6]-gingerol (12.5 mg/kg), and [6]-gingerol-β-CD (12.5 mg/kg). The treatments were administered orally for 5 days. On the third day, cisplatin was administered intraperitoneally (i.p.), and the animals were euthanized after 5 days. All biochemical parameters investigated, such as plasma urea and creatinine, urinary gamma GT, urinary protein, MPO, and GSH were altered by cisplatin. The parameters evaluated in this study were categorized into renal function, inflammation, and oxidative stress. Both [6]-gingerol and complexed gingerol effectively restored most of the evaluated parameters to control levels. Following these analyses, we investigated the JAK/STAT pathway and observed that gingerol deactivates this pathway, thereby preventing cisplatin-induced nephrotoxicity. In conclusion, β-CD complexation did not interfere with [6]-gingerol therapeutic, emphasizing its indication for future clinical tests. Further analysis showed that [6]-gingerol prevented cisplatin nephrotoxicity by deactivating JAK/STAT signaling pathway.

Enhancing the Solubility and Dissolution of Apigenin: Solid Dispersions Approach

Apigenin (APG), a bioactive flavonoid with promising therapeutic potential, suffers from poor water solubility, which limits its bioavailability. To address this, solid dispersions of APG were prepared using ball milling with sodium alginate (SA), Pluronic® F-68 (PLU68), Pluronic® F-127 (PLU127), PVP K30, and PVP VA64 as polymeric excipients. These dispersions were screened for apparent solubility in water and buffers with pH 1.2, 5.5, and 6.8. Based on improved solubility after 60 min, APG-PLU68 and APG-PLU127 dispersions were selected for further study. DSC and FT-IR analysis confirmed molecular interactions between APG and the polymer matrices, contributing to enhanced solubility and dissolution rates. Dissolution rate studies showed that APG-PLU127 achieved 100% solubility at pH 6.8, suggesting its potential use in environments such as the small intestine. Additionally, APG-PLU127 exhibited 84.3% solubility at pH 1.2, indicating potential for solid oral dosage forms, where APG could be absorbed in the acidic conditions of the stomach. The stability study confirmed that storage for one year under ambient conditions does not cause chemical degradation but affects the physical state and solubility of the dispersion. Antioxidant activity was assessed using the ABTS assay. Freshly obtained APG-PLU127 showed 68.1% ± 1.94% activity, whereas APG-PLU127 stored for one year under ambient conditions exhibited 66.2% ± 1.62% (significant difference, p < 0.05). The difference was related to a slight decrease in the solubility of APG in the solid dispersion (T0 = 252 ± 1 μg∙mL-1, T1 = 246 ± 1 μg∙mL-1). The findings demonstrate the superior performance of PLU127 as a carrier for enhancing the solubility, release, and antioxidant activity of APG.

Cyclodextrins and their potential applications for delivering vitamins, iron, and iodine for improving micronutrient status

Cyclodextrins (CDs) have been investigated as potential biopolymeric carriers that can form inclusion complexes with numerous bioactive ingredients. The inclusion of micronutrients (e.g. vitamins or minerals) into cyclodextrins can enhance their solubility and provide oxidative or thermal stability. It also enables the formulation of products with extended shelf-life. The designed delivery systems with CDs and their inclusion complexes including electrospun nanofibers, emulsions, liposomes, and hydrogels, show potential in enhancing the solubility and oxidative stability of micronutrients while enabling their controlled and sustained release in applications including food packaging, fortified foods and dietary supplements. Nano or micrometer-sized delivery systems capable of controlling burst release and permeation, or moderating skin hydration have been reported, which can facilitate the formulation of several personal and skin care products for topical or transdermal delivery of micronutrients. This review highlights recent developments in the application of CDs for the delivery of micronutrients, i.e. vitamins, iron, and iodine, which play key roles in the human body, emphasizing their existing and potential applications in the food, pharmaceuticals, and cosmeceuticals industries.

Study of Host-Guest Interaction and In Vitro Neuroprotective Potential of Cinnamic Acid/Randomly Methylated β-Cyclodextrin Inclusion Complex

Cinnamic acid (CA) has many beneficial effects on human health. However, its poor water solubility (0.23 g/L, at 25 °C) is responsible for its poor bioavailability. This drawback prevents its clinical use. To overcome the solubility limits of this extraordinary natural compound, in this study, we developed a highly water-soluble inclusion complex of CA with randomly methylated-β-cyclodextrin (RAMEB). The host-guest interaction was explored in liquid and solid states by UV-Vis titration, phase solubility analysis, FT-IR spectroscopy, and 1H-NMR. Additionally, molecular modeling studies were carried out. Both experimental and theoretical studies revealed a 1:1 CA/RAMEB inclusion complex, with a high apparent stability constant equal to 15,169.53 M-1. The inclusion complex increases the water solubility of CA by about 250-fold and dissolves within 5 min. Molecular modeling demonstrated that CA inserts its phenyl ring into the RAMEB cavity with its propyl-2-enoic acid tail leaning from the wide rim. Finally, a biological in vitro study of the inclusion complex, compared to the free components, was performed on the neuroblastoma SH-SY5Y cell line. None of them showed cytotoxic effects at the assayed concentrations. Of note, the pretreatment of SH-SY5Y cells with CA/RAMEB at 10, 30, and 125 µM doses significantly counteracted the effect of the neurotoxin MPP+, whilst CA and RAMEB alone did not show any neuroprotection. Overall, our data demonstrated that inclusion complexes overcome CA solubility problems, supporting their use for clinical applications.

Supramolecular deep eutectic solvents: Current advances and critical evaluation of cyclodextrins from solute to solvent in emerging functional food

The acceptance of nonconventional solvents as viable substitutes for traditional organic solvents has been widely recognized in order to comply with food-safety and sustainability regulations. Cyclodextrins (CDs), derived from starch, are cyclic oligosaccharides with the ability to form inclusion complexes with a variety of functional substances as the result of their distinctive structure, which enables them to effectively encapsulate bioactive compounds, rendering them highly sought after for use in food applications. In the implementing plan to achieve carbon-neutral emissions by 2050, the novel generation of supramolecular deep eutectic solvents (SUPRADES) has garnered increased attention and interest. The approach of utilizing SUPRADES as emerging solvents was just beginning to be applied to food studies. This review summarizes a revision of the current advances and critical evaluation of cyclodextrin-based SUPRADES (CD-based SUPRADES) as promising solvents for the enhancement of the extraction efficiency, solubilization and stability of bioactive compounds, adsorption and separation of food components, packaging materials, and modification of biopolymers. To meet the sustainable processing needs of the food industry, the emerging categories of CD-based SUPRADES need to be further fabricated. Herein, our review will sort out the potential application of CD-based SUPRADES in the food industry, aiming to provide a better understanding of CD-based SUPRADES within the viewpoint of food science. Formulation intricacies and scalability issues in real functional foods using CD-based SUPRADES as media need more efforts.

β-Cyclodextrin-based nanoassemblies for the treatment of atherosclerosis

Atherosclerosis, a chronic and progressive condition characterized by the accumulation of inflammatory cells and lipids within artery walls, remains a leading cause of cardiovascular diseases globally. Despite considerable advancements in drug therapeutic strategies aimed at managing atherosclerosis, more effective treatment options for atherosclerosis are still warranted. In this pursuit, the emergence of β-cyclodextrin (β-CD) as a promising therapeutic agent offers a novel therapeutic approach to drug delivery targeting atherosclerosis. The hydrophobic cavity of β-CD facilitates its role as a carrier, enabling the encapsulation and delivery of various therapeutic compounds to affected sites within the vasculature. Notably, β-CD-based nanoassemblies possess the ability to reduce cholesterol levels, mitigate inflammation, solubilize hydrophobic drugs and deliver drugs to affected tissues, making these nanocomponents promising candidates for atherosclerosis management. This review focuses on three major classes of β-CD-based nanoassemblies, including β-CD derivatives-based, β-CD/polymer conjugates-based and polymer β-CD-based nanoassemblies, highlighting a variety of formulations and assembly methods to improve drug delivery and therapeutic efficacy. These β-CD-based nanoassemblies exhibit a variety of therapeutic mechanisms for atherosclerosis and offer systematic strategies for overcoming barriers to drug delivery. Finally, we discuss the present obstacles and potential opportunities in the development and application of β-CD-based nanoassemblies as novel therapeutics for managing atherosclerosis and addressing cardiovascular diseases.

Encapsulation of apigenin into β-cyclodextrin metal-organic frameworks with high embedment efficiency and stability

In an effort to improve the application performance of apigenin, β-cyclodextrin metal-organic frameworks (BCDMOFs) known as porous materials were used to encapsulate apigenin via an innovative pH-adjusted method. The embedment efficiency had a significant positive pH dependence, reaching a maximum of 79.2 % ± 1.2 % at pH12. Scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and thermogravimetric analysis demonstrated formation of apigenin/BCDMOFs composites, and exposure of BCDMOFs pores facilitated high embedment efficiency. Storage stability experiment and kinetic analysis showed degradation of apigenin/BCDMOFs composites was less than that of apigenin alone. Apigenin stability was increased by approximately 18 % after 7 days. BCDMOFs effectively encapsulated and controlled the release of apigenin, and the composites exhibited improved application performance in vitro.

Hierarchically Templated Synthesis of 3D-Printed Crosslinked Cyclodextrins for Lycopene Harvesting

Plants produce a wide range of bioactive phytochemicals, such as antioxidants and vitamins, which play crucial roles in aging prevention, inflammation reduction, and reducing the risk of cancer. Selectively harvesting these phytochemicals, such as lycopene, from tomatoes through the adsorption method is cost-effective and energy efficient. In this work, a templated synthesis of 3D-printed crosslinked cyclodextrin polymers featuring nanotubular structures for highly selective lycopene harvesting is reported. Polypseudorotaxanes formed by triethoxysilane-based telechelic polyethylene glycols and α-cyclodextrins (α-CDs) are designed as the template to (1) synthetically access urethane-based nanotubular structures at the molecular level, and (2) construct 3D-printed architectures with designed macroscale voids. The polypseudorotaxane hydrogels showed good rheological properties for direct ink writing, and the 3D-printed hydrogels were converted to the desired α-CD polymer network through a three-step postprinting transformation. The obtained urethane-crosslinked α-CD monoliths possess nanotubular structures and 3D-printed voids. They selectively adsorb lycopene from raw tomato juice, protecting lycopene from photo- or thermo-degradations. This work highlights the hierarchically templated synthesis approach in developing functional 3D-printing materials by connecting the bottom-up molecular assembly and synthesis with the top-down 3D architecture control and fabrication.

Cyclodextrin Inclusion Complexes for Improved Drug Bioavailability and Activity: Synthetic and Analytical Aspects

Many active pharmaceutical ingredients show low oral bioavailability due to factors such as poor solubility and physical and chemical instability. The formation of inclusion complexes with cyclodextrins, as well as cyclodextrin-based polymers, nanosponges, and nanofibers, is a valuable tool to improve the oral bioavailability of many drugs. The microencapsulation process modifies key properties of the included drugs including volatility, dissolution rate, bioavailability, and bioactivity. In this context, we present relevant examples of the stabilization of labile drugs through the encapsulation in cyclodextrins. The formation of inclusion complexes with drugs belonging to class IV in the biopharmaceutical classification system as an effective solution to increase their bioavailability is also discussed. The stabilization and improvement in nutraceuticals used as food supplements, which often have low intestinal absorption due to their poor solubility, is also considered. Cyclodextrin-based nanofibers, which are polymer-free and can be generated using environmentally friendly technologies, lead to dramatic bioavailability enhancements. The synthesis of chemically modified cyclodextrins, polymers, and nanosponges based on cyclodextrins is discussed. Analytical techniques that allow the characterization and verification of the formation of true inclusion complexes are also considered, taking into account the differences in the procedures for the formation of inclusion complexes in solution and in the solid state.

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.

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.

Characterization of Thymoquinone-Sulfobutylether-β-Cyclodextrin Inclusion Complex for Anticancer Applications

Thymoquinone (TQ) is a quinone derived from the black seed Nigella sativa and has been extensively studied in pharmaceutical and nutraceutical research due to its therapeutic potential and pharmacological properties. Although the chemopreventive and potential anticancer effects of TQ have been reported, its limited solubility and poor delivery remain the major limitations. In this study, we aimed to characterize the inclusion complexes of TQ with Sulfobutylether-β-cyclodextrin (SBE-β-CD) at four different temperatures (293-318 K). Additionally, we compared the antiproliferative activity of TQ alone to TQ complexed with SBE-β-CD on six different cancer cell lines, including colon, breast, and liver cancer cells (HCT-116, HT-29, MDA-MB-231, MCF-7, SK-BR-3, and HepG2), using an MTT assay. We calculated the thermodynamic parameters (ΔH, ΔS, and ΔG) using the van't Holf equation. The inclusion complexes were characterized by X-ray diffraction (XRD), Fourier transforms infrared (FT-IR), and molecular dynamics using the PM6 model. Our findings revealed that the solubility of TQ was improved by ≥60 folds, allowing TQ to penetrate completely into the cavity of SBE-β-CD. The IC50 values of TQ/SBE-β-CD ranged from 0.1 ± 0.01 µg/mL against SK-BR-3 human breast cancer cells to 1.2 ± 0.16 µg/mL against HCT-116 human colorectal cancer cells, depending on the cell line. In comparison, the IC50 values of TQ alone ranged from 0.2 ± 0.01 µg/mL to 4.7 ± 0.21 µg/mL. Overall, our results suggest that SBE-β-CD can enhance the anticancer effect of TQ by increasing its solubility and bioavailability and cellular uptake. However, further studies are necessary to fully understand the underlying mechanisms and potential side effects of using SBE-β-CD as a drug delivery system for TQ.

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.

A Review of Cyclodextrin Encapsulation and Intelligent Response for the Release of Curcumin

To overcome the low water solubility and low bioavailability of curcumin (CUR), multiple delivery strategies have been proposed. Among these, cyclodextrin-based carriers have been widely used for the encapsulation and delivery of CUR. Cyclodextrins (CDs), as natural oligosaccharides, have been well known for their biodegradability, biocompatibility, non-toxicity, and internal hydrophobic and external hydrophilic structural features. This paper summarizes the recently reported CD-based carriers for encapsulating CUR. Particularly, the polymerization properties of CD self-assembly to enhance the encapsulation of CUR are discussed. In addition, the current progress on stimuli-responsive CD carriers for controlled release of CUR is described, which laid an important foundation for the development of CUR-based precision therapy in clinical practice. In conclusion, this review may provide ideas for the future development of a CD-based encapsulant for CUR.

Semisynthetic Derivatives of Pentacyclic Triterpenes Bearing Heterocyclic Moieties with Therapeutic Potential

Medicinal plants have been used by humans since ancient times for the treatment of various diseases and currently represent the main source of a variety of phytocompounds, such as triterpenes. Pentacyclic triterpenes have been subjected to numerous studies that have revealed various biological activities, such as anticancer, antidiabetic, anti-inflammatory, antimicrobial, and hepatoprotective effects, which can be employed in therapy. However, due to their high lipophilicity, which is considered to exert a significant influence on their bioavailability, their current use is limited. A frequent approach employed to overcome this obstacle is the chemical derivatization of the core structure with different types of moieties including heterocycles, which are considered key elements in medicinal chemistry. The present review aims to summarize the literature published in the last 10 years regarding the derivatives of pentacyclic triterpenes bearing heterocyclic moieties and focuses on the biologically active derivatives as well as their structure-activity relationships. Predominantly, the targeted positions for the derivatization of the triterpene skeleton are C-3 (hydroxyl/oxo group), C-28 (hydroxyl/carboxyl group), and C-30 (allylic group) or the extension of the main scaffold by fusing various heterocycles with the A-ring of the phytocompound. In addition, numerous derivatives also contain linker moieties that connect the triterpenic scaffold with heterocycles; one such linker, the triazole moiety, stands out as a key pharmacophore for its biological effect. All these studies support the hypothesis that triterpenoid conjugates with heterocyclic moieties may represent promising candidates for future clinical trials.

Synthesis and potential applications of cyclodextrin-based metal-organic frameworks: a review

Metal-organic frameworks are porous polymeric materials formed by linking metal ions with organic bridging ligands. Metal-organic frameworks are used as sensors, catalysts for organic transformations, biomass conversion, photovoltaics, electrochemical applications, gas storage and separation, and photocatalysis. Nonetheless, many actual metal-organic frameworks present limitations such as toxicity of preparation reagents and components, which make frameworks unusable for food and pharmaceutical applications. Here, we review the structure, synthesis and properties of cyclodextrin-based metal-organic frameworks that could be used in bioapplications. Synthetic methods include vapor diffusion, microwave-assisted, hydro/solvothermal, and ultrasound techniques. The vapor diffusion method can produce cyclodextrin-based metal-organic framework crystals with particle sizes ranging from 200 nm to 400 μm. Applications comprise food packaging, drug delivery, sensors, adsorbents, gas separation, and membranes. Cyclodextrin-based metal-organic frameworks showed loading efficacy of the bioactive compounds ranging from 3.29 to 97.80%.

Cellulose nanocrystals based delivery vehicles for anticancer agent curcumin

Cancer is a complex disease that starts with genetic alterations and mutations in healthy cells. The past decade has witnessed a huge demand for new biocompatibility and high-performance intelligent drug delivery systems. Curcumin (CUR) is a bioactive stimulant with numerous medical benefits. However, because of its hydrophobic nature, it has low bioavailability. The utilization of many biobased materials has been found to improve the loading of hydrophobic drugs. Cellulose nanocrystals (CNCs) with exceptional qualities and a wide range of applications, feature strong hydrophilicity and lipophilicity, great emulsification stability, high crystallinity and outstanding mechanical attributes. In this review, numerous CNCs-based composites have been evaluated for involvement in the controlled release of CUR. The first part of the review deals with recent advancements in the extraction of CNCs from lignocellulose biomass. The second elaborates some recent developments in the post-processing of CNCs in conjunction with other materials like natural polymers, synthetic polymers, β-CD, and surfactants for CUR loading/encapsulation and controlled release. Furthermore, numerous CUR drug delivery systems, challenges, and techniques for effective loading/encapsulation of CUR on CNCs-based composites have been presented. Finally, conclusions and future outlooks are also explored.

Flavonols and Flavones as Potential anti-Inflammatory, Antioxidant, and Antibacterial Compounds

Plant preparations have been used to treat various diseases and discussed for centuries. Research has advanced to discover and identify the plant components with beneficial effects and reveal their underlying mechanisms. Flavonoids are phytoconstituents with anti-inflammatory, antimutagenic, anticarcinogenic, and antimicrobial properties. Herein, we listed and contextualized various aspects of the protective effects of the flavonols quercetin, isoquercetin, kaempferol, and myricetin and the flavones luteolin, apigenin, 3 $\prime$ ,4 $\prime$ -dihydroxyflavone, baicalein, scutellarein, lucenin-2, vicenin-2, diosmetin, nobiletin, tangeretin, and 5-O-methyl-scutellarein. We presented their structural characteristics and subclasses, importance, occurrence, and food sources. The bioactive compounds present in our diet, such as fruits and vegetables, may affect the health and disease state. Therefore, we discussed the role of these compounds in inflammation, oxidative mechanisms, and bacterial metabolism; moreover, we discussed their synergism with antibiotics for better disease outcomes. Indiscriminate use of antibiotics allows the emergence of multidrug-resistant bacterial strains; thus, bioactive compounds may be used for adjuvant treatment of infectious diseases caused by resistant and opportunistic bacteria via direct and indirect mechanisms. We also focused on the reported mechanisms and intracellular targets of flavonols and flavones, which support their therapeutic role in inflammatory and infectious diseases.