Incorporation Of Quercetin Research Articles

Quercetin: Potential antidiabetic effects through enzyme inhibition and starch digestibility

AbstractDiabetes mellitus involves high blood sugar levels due to insufficient insulin action. Furthermore, enzymes such as α‐amylase and α‐glucosidase break down carbohydrates into glucose, leading to postprandial hyperglycemia. Flavonoids, particularly quercetin, inhibit these enzymes, slowing carbohydrate digestion and reducing glucose absorption. Quercetin has significant hypoglycemic effects with inhibitory concentration (IC50) values comparable to acarbose, a standard inhibitor, suggesting its potential as a natural alternative for diabetes management. In silico models, including molecular docking, molecular dynamics (MD) simulations, and quantitative structure‐activity relationship (QSAR) approaches, help researchers understand the molecular interactions of therapeutic agents. These techniques identify potential inhibitors, determine enzyme‐inhibitor structures, and calculate binding energies, correlating findings with in vitro or in vivo data. Molecular docking predicts molecular orientations, MD simulations offer insights into enzyme–inhibitor dynamics, and QSAR models predict inhibitory potential based on structural properties. Studies have shown that quercetin effectively inhibits α‐glucosidase and α‐amylase by forming hydrogen bonds with specific amino acid residues. Quercetin interacts with starches and reduces their digestibility, increases the formation of resistant starch, lowers the glycemic index, and inhibits digestive enzymes. Studies show that the effects of quercetin on starch digestion vary with concentration and type of starch, and its incorporation into foods such as bakery products, pasta, etc. can significantly decrease starch hydrolysis. The incorporation of quercetin into starch matrices may aid in the development of functional foods aimed at improving glycemic control.

Development of an antioxidant and anti-lipid peroxidation film based on quercetin-loaded Eudragit EPO®/sodium hyaluronate electrospun fibers

This study focuses on the development of a film based on electrospun fibers for the encapsulation of quercetin, to be applied as an antiradical and anti-lipid peroxidation system. Electrospun nanofibers based on Eudragit EPO (Eud EPO) and sodium hyaluronate (SH) with diameters ranging between 600 and 800 nm, and with smooth and/or rough surfaces were developed. Quercetin was successfully incorporated to the electrospun fiber system (≈92.1 %). Surprisingly, the free nanofibers showed great antiradical, reducing, and lipid antiperoxidation capacities. These properties were enhanced with the incorporation of quercetin, generating an enhanced synergistic effect. A film based on electrospun nanofibers with excellent biological properties was created through a simple method. Diverse bioactive compounds may enhance such biological properties. This system would have great potential for application within the biomedical sector.

A multifunctional hydrogel with mild photothermal antibacterial and antioxidant properties based on quercetin and dopamine-coated zinc oxide nanoparticles for healing bacteria-infected wound

Bacterial infection and inflammation hinder the natural healing process of skin wounds and may also cause wound complications. In light of the aforementioned considerations, this study developed an antibacterial and antioxidant QT/PDA@ZnO /QCS/(PAM-PAMPS) hydrogel (QPQH). The hydrogel dressing employs a dual network structure and incorporates quercetin (QT), quaternary ammonium salt chitosan (QCS), and polydopamine-coated zinc oxide nanoparticles (PDA@ZnO NPs) into a Polyacrylamide–Poly(2-acrylamido-2-methyl-1-propanesulfonic acid)（PAM-co-AMPS）hydrogel. This design enables QPQH to exhibit good mechanical properties, remarkable adhesion properties, and the capacity to adhere closely to the wound. The mild photothermal properties (˃50 °C) and Zn2+ release ability of PDA@ZnO NPs can cooperate with the destruction ability of QCS to bacterial cell membranes, thereby achieving efficient sterilization. This process has been demonstrated to be effective against Staphylococcus aureus and Escherichia coli, with approximately 98.5 % and 99.8 % efficiency, respectively. The incorporation of QT into hydrogel confers excellent antioxidant properties, which serve to reduce oxidative stress in wounds and prevent inflammation. Furthermore, hydrogel displays favorable blood compatibility and cell compatibility, facilitating the repair of bacteria-Infected wounds and promoting angiogenesis and collagen deposition in skin wounds. In conclusion, the antibacterial and antioxidant QPQH dressing has considerable potential for clinical use in the treatment of bacteria-Infected wounds.

Novel polydopamine-based composites with adjustable antioxidant activity

It is obtained here that dopamine and quercetin, not easily miscible compounds, can form stable quercetin – polydopamine (Q:PDA) composite systems under special conditions: oxidative polymerization of dopamine in the presence of quercetin in mixed water/ethanol solution at both, acidic and alkaline pH, by using NaIO4 as oxidant. The structure of the Q:PDA composites in bulk and as coating layers on SiO2 nanoparticles has been characterized by solid-state NMR spectroscopy, which directly confirms the incorporation of quercetin in the PDA matrix. Indirectly, it was also proved by HPTLC by monitoring quercetin released during Q:PDA disassembling in strongly acidic 0.1 M HCl solution. The morphology of Q:PDA coating layers has been characterized by AFM on glass substrates. It was found that, compared to PDA alone, layer thickness is increased in the presence of quercetin, reaching the highest value of about 190 nm for 1:1 quercetin/dopamine relative concentration, at pH 5.5 and 24 h deposition time. Sine quercetin is one of the most widely consumed natural antioxidant, and PDA has been reported with interesting antioxidant activity, the free radical scavenging properties of the Q:PDA composites was investigated. The free radicals bleaching activity was found dependent on the specific Q:PDA synthesis/deposition conditions, which might be of interest in biomedical applications that require adjustable antioxidant activity.

Cold atmospheric plasma modified polycaprolactone solution prior to electrospinning: A novel approach for improving quercetin-loaded nanofiber drug delivery systems

In this study, we present a novel approach for enhancing the performance of Quercetin-loaded nanofiber drug delivery systems through the modification of Polycaprolactone (PCL) solution using Cold Atmospheric Plasma (CAP) prior to electrospinning. CAP treatment was applied to PCL solutions for varying durations, namely, 0.5, 1, and 3 min. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) collectively demonstrate that CAP application and QU loading induce morphological changes in nanofibers, facilitating the creation of drug delivery systems with modified fiber diameters, devoid of bead formation. CAP treatment duration correlates with varying fiber diameters, with the longest treatment (3 min) producing the largest fibers (1324 ± 387 nm). Concurrently, the incorporation of quercetin (QU) into the PCL nanofibers resulted in reduced fiber diameter. These observations emphasize the pivotal role of CAP modification in tailoring nanofiber size and morphology. Notably, minimal peak shifts indicate no significant molecular structure changes in PCL nanofibers compared to PCL solutions, assuring the absence of unwanted chemical modifications or degradation during electrospinning. Furthermore, specific QU peaks are undetectable in Fourier-transform infrared (FTIR) spectra, suggesting dispersed or amorphous QU molecules within the nanofibers. Additionally, X-ray diffraction (XRD) results demonstrate that CAP treatment does not alter the crystalline structure of the PCL nanofiber drug delivery system. Crystalline planes of PCL remain unchanged, affirming stability under CAP treatment conditions. Water contact angles indicate that CAP treatment affects nanofiber hydrophobicity, with shorter CAP treatment times rendering more hydrophilic surfaces. Cumulative QU release percentages vary, with PCL/CAP-0.5-QU exhibiting the highest release at 56 ± 2.2 %, surpassing unmodified PCL/QU. Moreover, cell viability remains comparable or slightly increased when QU is incorporated into CAP-treated PCL nanofibers, suggesting potential mitigation of cytotoxic effects induced by CAP treatment. The combination of QU and CAP treatment enhances cancer cell viability reduction, QU release from nanofibers, and drug loading efficiency in a synergistic manner.

Validation of an HPLC-DAD Method for Quercetin Quantification in Nanoparticles.

The evaluation of the efficacy of incorporation of quercetin in nanoparticles is crucial, both for the development and quality control of pharmaceutical formulations. The validation of analytical methods for the precise quantification of quercetin is useful for the evaluation of various potential quercetin delivery systems and quercetin pharmacokinetics. This work aimed to validate a high-performance liquid chromatography with diode array detection (HPLC-DAD) method for quercetin detection and quantification in nanoparticles. Different mobile phase conditions and detection wavelengths (254 and 368 nm) were tested, and the major validation parameters were assessed (precision, accuracy, linearity, sensitivity, stability, and selectivity). The best peak resolution was obtained when quercetin was analyzed at 368 nm with a mobile phase of 1.5% acetic acid and a water/acetonitrile/methanol ratio of 55:40:5. Under these conditions, quercetin also eluted rapidly (retention time of 3.6 min). The method proved to be linear (R2 > 0.995), specific, and repeatable (variation coefficient between 2.4% and 6.7%) and presented intermediate precision (variation coefficient between 7.2% and 9.4%). The accuracy of the analysis ranged between 88.6% and 110.7%, and detection and quantification limits were 0.046 and 0.14 µg/mL, respectively. Quercetin solutions were more stable when stored at 4 °C than at room temperature or -20 °C. This validated method satisfied more parameters of bias assessment than most recent methods for quercetin determination and presented itself as more sensitive and efficient than general spectrophotometric methods. The method was successfully used for the analysis of quercetin incorporation in nanoparticles and will be evaluated in the future for its adequacy for the determination of quercetin in more complex matrices.

Flavonoid-incorporated starch and poly(vinyl alcohol) film: Sensitive and selective colorimetric sensor for copper identification and quantification in beverages and environmental samples

Colorimetric sensors based on an eco-friendly sensor molecule immobilized into a polymer matrix have broad applications for detecting trace elements. However, their potential for quantitative analysis of these elements remains little explored. Here, we incorporated rutin or quercetin into films based on starch, poly(vinyl alcohol), and glycerol to detect and quantify Cu2+ in different matrices. The films were characterized by colorimetric assays, thickness, and solubility analyses, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), differential scanning calorimetry (DSC), and mechanical assays. Incorporating the flavonoids in the film decreased its solubility, tensile strength, and modulus of elasticity, while increased its cross-sectional surface irregularity. XRD and DSC results indicated an increase in film crystallinity in the presence of rutin or quercetin. FTIR analyses showed a more effective incorporation of quercetin than rutin in the polymeric matrix, which was confirmed by flavonoid release studies from the film. The film containing quercetin exhibited selectivity in identifying copper in liquid matrices, changing its color from light yellow to dark yellow. An analytical method to quantify Cu2+ was developed, presenting a linear response range of 0.20–1.20 mg L−1, with detection and quantification limits of 0.060 and 0.20 mg L−1, respectively, very lower than other methods based on polymeric matrices containing natural dyes. The method was successfully applied for Cu2+ determination in cachaça and tap water samples, achieving high accuracy (96–104% of recovery) and precision (relative standard deviation < 6.7%). Our findings represent an advancement in the field of sensors based on natural dyes, demonstrating that such sensors can achieve high sensitivity without the need for complex sample preparation methods.

Zein-based nanospheres and nanocapsules for the encapsulation and oral delivery of quercetin

In this study, the ability of zein nanospheres (NS) and zein nanocapsules containing wheat germ oil (NC) to enhance the bioavailability and efficacy of quercetin was evaluated. Both types of nanocarriers had similar physico-chemical properties, including size (between 230 and 250 nm), spherical shape, negative zeta potential, and surface hydrophobicity. However, NS displayed a higher ability than NC to interact with the intestinal epithelium, as evidenced by an oral biodistribution study in rats. Moreover, both types of nanocarriers offered similar loading efficiencies and release profiles in simulated fluids. In C. elegans, the encapsulation of quercetin in nanospheres (Q-NS) was found to be two twice more effective than the free form of quercetin in reducing lipid accumulation. For nanocapsules, the presence of wheat germ oil significantly increased the storage of lipids in C. elegans; although the incorporation of quercetin (Q-NC) significantly counteracted the presence of the oil. Finally, nanoparticles improved the oral absorption of quercetin in Wistar rats, offering a relative oral bioavailability of 26% and 57% for Q-NS and Q-NC, respectively, compared to a 5% for the control formulation. Overall, the study suggests that zein nanocarriers, particularly nanospheres, could be useful in improving the bioavailability and efficacy of quercetin.

Synthesis and characterization of quercetin-layer double hydroxide (LDH) nanohybrid and their enhanced antioxidant activity

ABSTRACT. This research included the synthesis of pristine nitrate-type Zn2Al-LDH by means of Co-precipitation, which was then followed by hydrothermal treatment. Ion exchange is used to stabilize the produced pristine LDH nano layer, which is used for the encapsulation of bioactive molecules. Quercetin, which has an antioxidant function, is used. XRD was used to investigate the newly synthesized quercetin-LDH (QC-LDH) compound. Quercetin was discovered to be entirely deprotonated as a result of XRD research, and it was also shown to be stabilized in between LDH lattices as a result of electrostatic contact. On the basis of the diphenyl picrylhydrazyl (DPPH) method, the anti-oxidant property was discussed, and it was discovered that the quercetin that was free from the LDH layer helped as an owing antioxidant to scavenge DPPH radicals in ethanol solvent at concentrations ranging from 80-100%, depending on the concentration level. The powder X-ray diffraction patterns indicate that the incorporation of quercetin into the interlayer led to an expansion of the interlayer arrangement to 0.88 and 1.46 nm, respectively. According to the findings of a variety of characterization techniques, the QC-LDH may be regarded as a good antioxidant material with potential drug delivery system.&#x0D; &#x0D; KEY WORDS: Layer double hydroxide, Antioxidant activity, Quercetin, Biocompatibility&#x0D; &#x0D; Bull. Chem. Soc. Ethiop. 2023, 37(4), 917-929.&#x0D; DOI: https://dx.doi.org/10.4314/bcse.v37i4.9

Engineering of poly(caprolactone) and poly(glycerol sebacate) small-diameter vascular prosthesis with quercetin.

The fabrication of biodegradable, bioabsorbable, and biocompatible vascular scaffolds with enhanced mechanical and biological properties that are able to modulate local inflammation and induce endothelialization after surgical implant is still a challenge. In this work, a fibrous scaffold, made of poly(ε-caprolactone) and poly(glycerol sebacate), was fabricated to be potentially used as a small-diameter graft in vascular surgery. The novelty of this research is represented by the direct incorporation of quercetin, a well-known antioxidant compound with several biologicalproperties, into a polymeric scaffold obtaining a vascular construct able to modulate two key factors involved in postsurgical inflammation, matrix metalloproteinase-9 and endothelial nitric oxide synthase. For its production, an electrospinning apparatus, a solution made of the two polymers (both 20% (w/v), mixed at the ratio 1:1 (v/v)), and free quercetin (0.05% (w/v))were used. Scanning electron and atomic force microscopies were employed to investigate the morphological properties of the fabricated electrospun scaffolds. Furthermore, physicochemical properties, includingFourier-transform infrared spectroscopy, mass loss, fluid uptake, quercetin release, mechanical properties, and biological activity of the scaffolds were studied. The expression of matrix metalloproteinase-9, tissue inhibitor of metalloproteinase-1, and of endothelial nitric oxide synthase was evaluated when the quercetin-functionalized scaffold was exposed to human endothelial cells treated with tumor necrosis factor-α. The results of this study confirmed the feasibility of incorporating free quercetin during the electrospinning process to impart biological properties to small-diameter vascular prostheses.

Structural and material characterization of quercetin incorporated soy protein isolate films

Owing to their degradability and fair film forming properties, protein films are captivating interest for development of packaging materials. However, poor water barrier properties and low mechanical strength limits its commercial application. Incorporation of additives such as phenolic compounds are reported to overcome these limitations. Our study aimed to explore the effect of quercetin and different processing methods on structural and mechanical properties of soy protein films. In our work, quercetin (flavonoid) was used to improve the material properties of proteinous films. The prepared films were evaluated for their physical properties, mechanical properties and water barrier capacity. The incorporation of quercetin had an obvious influence on the colour of film due to inherent pigmentation nature and resulted in generation of intense brown coloration of modified films. The opacity and cross linking of films were linearly increased with addition of quercetin. The mechanical properties of modified films were improved as indicated by increased tensile strength compared to the unmodified films. The incorporation of quercetin shifted the film towards hydrophilicity as indicated by increased water uptake activity of modified films compared to control films. Quercetin was found to form stable interaction with SPI as there was very little leaching observed from films. The results demonstrated that quercetin holds the potential to enhance the properties of SPI films which could be possibly employed in the development of packaging materials.

Thymidine phosphorylase as a molecular target for quercetin-incorporated collagen matrix in the prevention of hand-foot syndrome induced by capecitabine in rats.

Hand-foot syndrome (HFS) is a common adverse effect of capecitabine affecting the quality of life of cancer patients. To enhance the tolerability of capecitabine, this work evaluated the incorporation of quercetin into topical collagen matrix formula to target thymidine phosphorylase enzyme, oxidative stress, and apoptosis underlying HFS. Forty Sprague Dawley rats were allocated to four equal groups. The control group received distilled water orally. HFS was induced by oral capecitabine (200 mg/kg/day) for 21 days. The untreated HFS group received no treatment. In the treated groups, topical collagen and quercetin-incorporated collagen matrix formula were administered concomitantly with the HFS induction protocol. Treatment with quercetin-incorporated collagen matrix showed a significant decrease in thymidine phosphorylase level compared with the untreated and collagen-treated groups. Treatment with quercetin-incorporated collagen matrix showed a significant decrease in malondialdehyde and caspase-3 levels, and a significant increase in the total antioxidant capacity of the skin and B cell lymphoma/leukemia 2 levels compared with the untreated group. Additionally, a significant improvement in the gross picture and histopathological score of HFS was observed. In conclusion, the quercetin-incorporated collagen matrix is a promising formula for the prevention of HFS, due to the targeted effect on thymidine phosphorylase and subsequent antioxidant and antiapoptotic effects.

Effects of Quercetin and Organically Modified Montmorillonite on the Properties of Poly(butylene adipate-co-terephthalate)/Thermoplastic Starch Active Packaging Films.

The poly(butylene adipate-co-terephthalate) (PBAT)/thermoplastic starch (TPS) film stands out owing to its acceptable price, low impact on the environment, and excellent mechanical properties. The main objective of this study was to improve the antioxidant properties of the PBAT/TPS film by incorporation of quercetin (Q) through the extrusion blow process. Another specific objective was to incorporate the organically modified montmorillonite (OMMT) to prolong the release of Q and improve the poor barrier properties of the PBAT/TPS/Q film. The films were analyzed in terms of their morphology, mechanical properties, gas and water barrier properties, and antioxidant and anti-UV properties. Optimization of the OMMT content resulted in a fiber-like, co-continuous morphology of the PBAT/TPS/Q film. The incorporation of quercetin enhanced the antioxidant and anti-UV properties of the PBAT/TPS film, while OMMT improved the mechanical properties, ultraviolet barriers, and gas and water barrier properties. The results show that the films incorporating Q and OMMT provided the oxygen and water barrier by up to 94 and 54%, respectively. Also, the amount of polymer required for 50% 2,2-diphenyl-1-picrylhydrazyl (DPPH) inhibition is as low as 0.03 g, and the UV transmission rate was reduced by about 50%. Moreover, PBAT/TPS/Q/OMMT films successfully delayed the decay of the banana and blueberry due to their excellent antioxidant properties and suitable water vapor permeability.

Quercetin-Embedded Gelastin Injectable Hydrogel as Provisional Biotemplate for Future Cutaneous Application: Optimization and In Vitro Evaluation.

Chronic wounds have become an epidemic in millions of patients and result in amputations. In order to overcome this, immediate treatment is a realistic strategy to minimize the risk of complications and aid in the healing rate of the cutaneous wound. Functionalized engineered biomaterials are proven to be a potential approach to embarking on skin wound management. Thus, this study aimed to evaluate the efficacy of a quercetin-embedded gelatin–elastin (Gelastin) injectable hydrogel to act as a provisional biotemplate with excellent physicochemical properties, to be utilized for future cutaneous application. Briefly, the hydrogel was homogenously pre-mixed with genipin (GNP), followed by the incorporation of quercetin (QC). The physicochemical properties comprised the contact angle, swelling ratio, crosslinking degree, enzymatic biodegradation, and water vapor transmission rate (WVTR), as well as chemical characterization. Energy-dispersive X-ray (EDX), XRD, and Fourier transform infra-red (FTIR) analyses were conducted. Briefly, the findings demonstrated that the crosslinked hybrid biomatrix demonstrated better resilience at >100%, a contact angle of >20°, a swelling ratio average of 500 ± 10%, a degradation rate of <0.05 mg/hour, and a successful crosslinking degree (<70%free amine group), compared to the non-crosslinked hybrid biomatrix. In addition, the WVTR was >1500 g/m2 h, an optimal moisture content designed to attain regular cell function and proliferation. The outcomes convey that Gelastin-QC hydrogels deliver the optimum features to be used as a provisional biotemplate for skin tissue engineering purposes.

Quercetin improves rapid endothelialization and inflammatory microenvironment in electrospun vascular grafts

There is a great need for small diameter vascular grafts among patients with cardiovascular diseases annually. However, continuous foreign body reactions and fibrosis capsules brought by biomaterials are both prone to poor vascular tissue regeneration. To address this problem, we fabricated a polycaprolactone (PCL) vascular graft incorporated with quercetin (PCL/QCT graft) in this study. In vitro cell assay showed that quercetin reduced the expressions of pro-inflammatory genes of macrophages while increased the expressions of anti-inflammatory genes. Furthermore, in vivo implantation was performed in a rat abdominal aorta replacement model. Upon implantation, the grafts exhibited sustained quercetin release and effectively enhanced the regeneration of vascular tissue. The results revealed that quercetin improved endothelial layer formation along the lumen of the vascular grafts at four weeks. Furthermore, the thickness of vascular smooth muscle layers significantly increased in PCL/QCT group compared with PCL group. More importantly, the presence of quercetin stimulated the infiltration of a large amount of M2 phenotype macrophages into the grafts. Collectively, the above data reinforced our hypothesis that the incorporation of quercetin may be in favor of modulating the inflammatory microenvironment and improving vascular tissue regeneration and remodeling in vascular grafts.

Multifunctional nanocomposite active packaging materials: Immobilization of quercetin, lactoferrin, and chitosan nanofiber particles in gelatin films

The design and fabrication of multifunctional films from natural materials is a major focus of modern packaging research with the aim of creating smart, active, and/or biodegradable packaging. In this study, multifunctional films were created by embedding different kinds of functional nanoparticles into a gelatin-based film prepared by a casting method. The nanoparticles were prepared by crosslinking cationic chitosan nanofibers using anionic sodium tripolyphosphate ions. In some cases, quercetin, lactoferrin, or both were incorporated into these nanoparticles. The nanoparticles were mixed with the hot gelatin solution prior to casting. The appearance, light-screening, water vapor barrier, thermal, mechanical, antimicrobial, antioxidant, and biodegradability/composting characteristics of the nanoparticle-loaded films were then characterized. Dynamic light scattering showed that the size, polydispersity, and charge of the functional nanoparticles depended on their composition. The spectroscopic analysis identified the importance of electrostatic and hydrogen bonds in film formation. Incorporation of the functional nanoparticles into the gelatin films improved their optical, mechanical, barrier, and preservative properties. For instance, the incorporation of quercetin increased the ability of the films to screen UV-light, whereas the incorporation of both lactoferrin and quercetin increased the antimicrobial and antioxidant properties of the films. Finally, the films were shown to have good biodegradability/composting under environmental conditions, which is important for reducing the negative environmental impacts caused by synthetic packaging.

Cytotoxicity of adducts formed between quercetin and methylglyoxal in PC-12 cells

Quercetin (Que) or quercetin-containing food stuffs are widely incorporated in bakery foods for improving food texture and health effects, and scavenging reactive aldehydes, such as methylglyoxal (MGO) that exhibits various deleterious effects including contribution to neurodegeneration. This study aimed to investigate the cytotoxicity of the adducts formed between quercetin and MGO resulted from the incorporation of quercetin in foods. Two highly-purified adducts (Que-mono-MGO and Que-di-MGO) were found to display higher cytotoxicity than their precursor MGO and quercetin. They elevated apoptosis via upregulation of expression of apoptotic markers, including p-P38, cleaved caspase-9 and -3, and pro-apoptotic Bax. They induced mitochondrial dysfunction via decreasing mitochondrial membrane potential and increasing lactate dehydrogenase release. Moreover, they attenuated levels of p-Akt, Nrf2, NQO-1, and HO-1, proving that they induced neurodegeneration apoptosis through mitochondria-mediated signaling pathways (PI3K-Akt and Nrf2-HO-1/NQO-1). These findings indicated that the safety consequence of MGO after scavenged by polyphenols needs to be concerned.

Polyphenols and Brazilian red propolis incorporated into a total-etching adhesive system help in maintaining bonding durability

ObjectivesThe aim of this study was to evaluate the degree of conversion and bond strength of a commercial dental adhesive modified by the incorporation of quercetin, resveratrol (RES), and Brazilian red propolis (BRP). MethodsBRP markers were identified using ultra-performance liquid chromatography coupled with a diode array detector, and the antioxidant activity (AAO) of the three substances was analyzed. Single Bond 2 adhesive (3M ESPE) was modified by adding BRP, quercetin, and RES, separately, at 20 μg/mL, 250 μg/mL, and 500 μg/mL, respectively. The degree of conversion (DC) was measured using near-infrared spectroscopy 24 h after photopolymerization. Measurements of the resin-dentin microtensile bond strength (μTBS) were carried out after 1 day and 1 year. Student's t test and ANOVA with Tukey's test were used for data analysis (α = 0.05). ResultsThe markers daidzein, liquiritigenin, pinobanksin, isoliquiritigenin, formononetin, pinocembrin, and biochanin A were found in the ethanolic extract of BRP. Quercetin, RES, and BRP showed high AAO. The DC of the tested adhesives remained adequate for this category of material, with a slight increase in the DC of adhesives with quercetin and BRP (P > 0.05). Comparisons between μTBS measurements made at 1 day and 1 year showed that, contrary to the control group, μTBS values for all modified adhesives were maintained after 1 year in distilled water (P > 0.05). ConclusionsThese findings suggest that quercetin, RES, or BRP might be useful in adhesive dentistry to help improve hybrid layer resistance. Clinical significanceDentin bonding agents with quercetin, RES, and BRP have potential to increase the longevity of composite restorations.

Hyaluronidase Inhibitor-Incorporated Cross-Linked Hyaluronic Acid Hydrogels for Subcutaneous Injection.

Hyaluronidase (HAase) inhibitor-incorporated hyaluronic acid (HA) hydrogel cross-linked with 1,4-butanediol diglycidyl ether (BDDE) was designed to reduce the toxicity risk induced by BDDE and its biodegradation rate in subcutaneous tissue. The formulation composition of hydrogel and its preparation method were optimized to have a high swelling ratio and drug content. Quercetin (QCT) and quetiapine (QTP), as an HAase inhibitor and model drug, respectively, were incorporated into the cross-linked hydrogel using the antisolvent precipitation method for extending their release after subcutaneous injection. The cross-linked HA (cHA)-based hydrogels displayed appropriate viscoelasticity and injectability for subcutaneous injection. The incorporation of QCT (as an HAase inhibitor) in the cHA hydrogel formulation resulted in slower in vitro and in vivo degradation profiles compared to the hydrogel without QCT. Single dosing of optimized hydrogel injected via a subcutaneous route in rats did not induce any acute toxicities in the blood chemistry and histological staining studies. In the pharmacokinetic study of rats following subcutaneous injection, the cHA hydrogel with QCT exhibited a lower maximum QTP concentration and longer half-life and mean residence time values compared to the hydrogel without QCT. All of these results support the designed HAase inhibitor-incorporated cHA hydrogel being a biocompatible subcutaneous injection formulation for sustained drug delivery.

Effect of Quercetin Supplementation in Extender on Sperm Kinematics, Extracellular Enzymes Release, and Oxidative Stress of Egyptian Buffalo Bulls Frozen-Thawed Semen.

Buffalo spermatozoa are more sensitive for cryopreservation compared to other species. This study aimed to evaluate the consequences of quercetin against cryodamage of buffalo frozen–thawed spermatozoa characteristics. Semen of Egyptian bulls (n = 4) was extended in OptiXcell extender incorporated with quercetin at 0 (control), 2.5, 5.0, 10.0, 20.0, 40.0, and 80.0 μM before cryopreservation. Frozen–thawed semen was evaluated for sperm motility by computer-assisted sperm analyzer (CASA), viability, morphology, membrane, and acrosome integrities. The kinematics parameters including average path velocity (VAP; μm/s), straight linear velocity (VSL; μm/s), curvilinear velocity (VCL; μm/s), amplitude of lateral head displacement (ALH; μm), beat cross frequency (BCF; Hz), linearity [LIN, (VSL/VCL) × 100], and straightness [STR, (VSL/VAP) × 100] were assessed. The sperm-free extender was evaluated for aspartate aminotransferase (AST), alanine aminotransferase (ALT), and H2O2. Homogenized sperm cells were evaluated for oxidative stress biomarkers [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX)], and lipid peroxidation [malondialdehyde (MDA)]. The highest values of total motility, progressive motility, viability, intact acrosome, and membrane integrity substantially improved with 10 μM of quercetin. STR (%) was substantially low (P < 0.01), and VCL (μm/s) and ALH (μm) were markedly high (P < 0.05) in 10 μM of quercetin. The outflow of ALT enzyme to extracellular fluid was lower with 10 μM of quercetin (P < 0.001) and higher at 2.5 μM of quercetin. The spermatozoa leaked AST was markedly lower at 5.0, 10 (P < 0.001) and 20 μM (P < 0.05) of quercetin. The activity of antioxidant enzymes was eminently low at all quercetin concentrations, and this was accompanied by the decrease in H2O2 in the media. SOD activity at 10–80 μM, CAT at 5.0–40 μM, and GPX at 2.5–80.0 μM of quercetin in spermatozoa were substantially low. MDA level significantly (P < 0.001) decreased at all quercetin concentrations. In conclusion, the incorporation of quercetin at the level of 10 μM is promising in improving buffalo semen characteristics and lower the freezing–thawing oxidative stress.