Pharmacotechnical, Physico-Chemical, and Antioxidant Evaluation of Newly Developed Capsule Formulations

The excess of free radicals causes numerous imbalances in the body that lead to premature aging, the degradation of internal structures, and the appearance of numerous pathologies responsible for the increased risk of premature death. The present work aims to evaluate the physical, chemical, pharmacotechnical, and antioxidant activity of newly achieved capsule formulations. These two formulations were F1_a.i., which contains melatonin:biotin:coenzyme Q10 (weight ratio of 1:2:60), and F2_a.i., which contains quercetin:resveratrol:biotin:coenzyme Q10 (weight ratio of 10:10:1:10). The adequate selection of the excipient types and amounts for final capsule formulations (F1_c.c., F2_c.c.) was based on preformulation studies performed on the powders containing active ingredients. The antioxidant activity assessed using three methods (ABTS, DPPH, and FRAP) compared with acid ascorbic as a positive control demonstrated that the F2_c.c. formulation possesses the strongest antioxidant capacity. The results confirmed the suitable formulation and the accurate selection of the types and amounts of active ingredients, as well as the auxiliary excipients used in newly developed capsule formulations as supplements with an excellent antioxidant effect on the human body.

Quercetin@Gd3+ doped Prussian blue nanocubes induce the pyroptotic death of MDA-MB-231 cells: combinational targeted multimodal therapy, dual modal MRI, intuitive modelling of r1-r2 relaxivities

Quercetin (Qu), a potential bioflavonoid has gained considerable interest as a promising chemotherapeutic drug which can inhibit the proliferation of triple-negative breast cancer (TNBC) cells due to its regulation of the expression of tumor-suppressor gene metastasis and antioxidant property. Notably, Qu exhibits a very negligible cytotoxic effect on normal cells, even with high-dose treatment, while it is shows high affinity to TNBC. However, the efficiency of Qu is limited clinically due to its poor bioavailability, caused by its low aqueous solubility (2.15 μg mL^-1 at 25 °C), rapid gastrointestinal digestion and chemical instability in alkaline and neutral media. Herein, polydopamine (PDA)-coated, NH₂-PEG-NH₂ and hyaluronic acid (HA)-functionalized Gd³⁺-doped Prussian blue nanocubes (GPBNC) are reported as a multifunctional platform for the codelivery of Qu as a chemotherapeutic agent and GPBNC as a photodynamic (PDT) and photothermal (PTT) agent with improved therapeutic efficiency to overcome theses barriers. PDA, NH₂-PEG-NH₂ and HA stabilize GPBNC@Qu and facilitate bioavailability and active-targeting, while absorption of near infrared (NIR) (808 nm; 1 W cm^-2) induces PDT and PTT activities and dual T₁-T₂-weighted magnetic resonance imaging (MRI) with high relaxometric parameters (r₁ 10.06 mM^-1 s^-1 and r₂ 24.96 mM^-1 s^-1 at a magnetic field of 3 T). The designed platform shows a pH-responsive Qu release profile and NIR-induced therapeutic efficiency of ∼79% in 20 minutes of irradiation, wherein N-terminal gardermin D (N-GSDMD) and a P2X7-receptor-mediated pyroptosis pathway induces cell death, corroborating the up-regulation of NLRP3, caspase-1, caspase-5, N-GSDMD, IL-1β, cleaved Pannexin-1 and P2X7 proteins. More interestingly, the increasing relaxivity values of Prussian blue nanocubes with Gd³⁺ doping have been explained on the basis of Solomon-Bloembergen-Morgan theory, considering inner- and outer-sphere relaxivity, wherein crystal defects, coordinated water molecules, tumbling rate, metal to water proton distance, correlation time, magnetisation value etc. play a significant role. In summary, our study suggests that GPBNC could be a beneficial nanocarrier for theranostic purposes against TNBC, while our conceptual study clearly demonstrates the role of various factors in increasing relaxometric parameters.

Quercetin-Loaded Mesoporous Silica Nanoparticle-Based Lyophilized Tablets for Enhanced Physicochemical Features and Dissolution Rate: Formulation, Optimization, and In Vitro Evaluation

Mesoporous silica nanoparticles (MSNPs) have been proposed as a potential approach for stabilizing the amorphous state of poorly water-soluble actives. This study aimed to improve the physiochemical characteristics of poorly water-soluble quercetin (QT) through a novel lyophilized formulation. Various parameters, including solvent polarity, QT-carrier mass ratio, and adsorption time, were studied to improve the loading of QT into MSNPs. The optimized loaded MSNPs were formulated into lyophilized tablets through a freeze-drying process using hydrophilic polyvinylpyrrolidone (PVP-K30) as a polymeric stabilizer and water-soluble sucrose as a cryoprotectant. The effect of PVP-K30 and sucrose on the particle size, disintegration time, friability, and time required to release 90% of QT were studied using 3² full factorial design. The optimized formula was characterized using different evaluating techniques; for instance, differential scanning calorimetry, X-ray diffractometry, Fourier transform infrared spectroscopy, drug content, moisture content, and saturation solubility. The analysis proved that QT was consistently kept in the nanosize range with a narrow size distribution. The loaded silica nanoparticles and the optimized formulation are in an amorphous state devoid of any chemical interaction with the silica matrix or the lyophilization excipients. The optimized formula also featured low friability (less than 1%), fast disintegration (< 30 s), and a pronounced enhancement in saturation solubility and dissolution rate. Briefly, we established that the lyophilized MSNPs-based tablet would be a potential strategy for improving the rate of dissolution and, ultimately, the bioavailability of the poorly water-soluble QT.

Click gold quantum dots biosynthesis with conjugation of quercetin for adenocarcinoma exertion

We developed a cost-effective and eco-friendly click biosynthesis of small molecule quercetin-gold quantum dots (QRT-AuQDs) involving quick conjugation using an ultrasonication method at ambient temperature by utilizing QRT and gold ions in the proportion of 0.1 : 1 (molar ratio). A comparatively very short amount of time (60 seconds) was required as compared to conventional procedures. The present biomimetics research relates to the isolation of bioactive QRT by the circularly spread silica gel layer technique (CSSGLT) and characterization (UV-Vis, FTIR, NMR and DSC analysis). Characterization of the synthesized QRT-AuQDs conjugated complex was carried out by UV-Vis, HR-TEM, DLS, zeta potential and X-ray diffraction. The main objective of the present work was to study the comparative anticancer activity of QRT and QRT-AuQDs on human lung cancer HOP-62 and leukemia K-562 cell lines. The results suggested that QRT-AuQDs showed potential for applications in anticancer treatment and were found to be a more cytotoxic agent in comparison to QRT, causing > 50% inhibition of cancer cells at the concentration < 10-7 M. Hence, small molecule conjugated QRT-AuQDs can be used as a promising material for biomedical, bioengineering and anti-infectives applications.

Evaluation of Antioxidants Using Electrochemical Sensors: A Bibliometric Analysis

The imbalance of oxidation and antioxidant systems in the biological system can lead to oxidative stress, which is closely related to the pathogenesis of many diseases. Substances with antioxidant capacity can effectively resist the harmful damage of oxidative stress. How to measure the antioxidant capacity of antioxidants has essential application value in medicine and food. Techniques such as DPPH radical scavenging have been developed to measure antioxidant capacity. However, these traditional analytical techniques take time and require large instruments. It is a more convenient method to evaluate the antioxidant capacity of antioxidants based on their electrochemical oxidation and reduction behaviors. This review summarizes the evaluation of antioxidants using electrochemical sensors by bibliometrics. The development of this topic was described, and the research priorities at different stages were discussed. The topic was investigated in 1999 and became popular after 2010 and has remained popular ever since. A total of 758 papers were published during this period. In the early stages, electrochemical techniques were used only as quantitative techniques and other analytical techniques. Subsequently, cyclic voltammetry was used to directly study the electrochemical behavior of different antioxidants and evaluate antioxidant capacity. With methodological innovations and assistance from materials science, advanced electrochemical sensors have been fabricated to serve this purpose. In this review, we also cluster the keywords to analyze different investigation directions under the topic. Through co-citation of papers, important papers were analyzed as were how they have influenced the topic. In addition, the author’s country distribution and category distribution were also interpreted in detail. In the end, we also proposed perspectives for the future development of this topic.

Vanadium-Flavonoid Complexes: A Promising Class of Molecules for Therapeutic Applications

Several reports have revealed the superior biological activity of metal ion-flavonoid complexes when compared with the parent flavonoid. Among the different metal ions explored, vanadium and its compounds are in the forefront because of their anticancer and antidiabetic properties. However, the toxicity of vanadium-based ions and their inorganic derivatives limits their therapeutic applications. Complexation of vanadium with flavonoids not only reduces its adverse effects but also augments its biological activity. This Review discusses the nature of coordination in vanadium-flavonoid complexes, their structure-activity correlations, with special emphasis on their therapeutic activities. Several investigations suggest that the superior biological activity of vanadium complexes arise because of their ability to regulate metabolic pathways distinct from those acted upon by vanadium alone. These studies serve to decipher the underlying molecular mechanism of vanadium-flavonoid complexes that can be explored further for generating a series of novel compounds with improved pharmacological and therapeutic performance.

A coordinated ruthenium-rifampicin complex reprogramming the colon carcinoma micro-environment mediated by modulation of p53/AkT/mTOR/VEGF pathway

WHO suggests that colon cancer incidences are rising steadily, propelling researchers to search for novel chemotherapeutic options. Metal-based chemotherapy is a potential forte to explore ruthenium-based complexes, exhibiting the capability to influence a variety of cellular targets. We discovered the chemotherapeutic effects of ruthenium-rifampicin complex on HT-29 and HCT-116 human colorectal cell lines and on a chemically developed murine colorectal cancer model. Complex was synthesized and characterized by analytical techniques and evaluation of antioxidant potential along with DNA binding capabilities. The complex minimizes cellular propagation and initiates apoptotic events in the colon cancer cell lines of HT-29 and HCT-116. The results of the in vivo study suggest that the complex has been successful in minimizing the wide spectrum of aberrant crypt foci and hyperplastic lesions, as well as encouraging elevated amounts of CAT, SOD and glutathione. Along with that, p53 could be modulated by the ruthenium-rifampicin complex to interfere with apoptosis in colon carcinoma, initiated by the intrinsic apoptotic trail facilitated through Bcl2 and Bax, thus controlling the Akt/mTOR/VEGF pathway coupled through the WNT/β-catenin trail. Ruthenium-rifampicin chemotherapy could interrupt, retract or interrupt the progression of colorectal cancer through modifying intrinsic apoptosis including the antiangiogenic pathway, thereby achieving the function of a potential contender in chemotherapy in the near future.

Development and evaluation of a multi-functional organic-inorganic nanotheranostic hybrid for pancreatic cancer therapy

Pancreatic cancer is a highly invasive disease with low survival rates. The high death rates associated with pancreatic cancer are due to multiple factors including late stage diagnosis, multi-drug resistance, invasive nature and restricted access of the therapeutic moiety to the cancer cells due to the stroma. Smart multifunctional nanocarriers that deliver the therapeutic agent in to the cancer tissue as well as enable imaging of the tissue represent an emerging paradigm in cancer therapy. Accurate and reliable detection of cancerous lesions in pancreas is essential for designing appropriate therapeutic strategy to annihilate the highly aggressive pancreatic cancer. A combination of imaging modalities can enhance the reliability of cancer detection. In this context, we report here a hybrid iron oxide-gold nanoparticle with dual contrast enhancing ability for both magnetic resonance imaging (MRI) and micro-computed tomography (micro-CT) that is co-encapsulated with the nucleotide analogue gemcitabine in a chitosan matrix. The theranostic system displayed enhanced cytotoxicity against PanC-1 pancreatic cancer cells when compared to normal cells over 48 h due to differences in cell internalization. The iron oxide-gold hybrid enabled visualization of the theranostic nanoparticle by MRI as well as micro-CT. Further, the magnetocaloric effect of the iron oxide enabled faster release of the chemotherapeutic agent as well as augmented the cytotoxicity by inducing hyperthermia. This system holds promise for further exploration as an integrated diagnostic and therapeutic platform for pancreatic cancer.

A Novel Ruthenium-Fluvastatin Complex Downregulates SNCG Expression to Modulate Breast Carcinoma Cell Proliferation and Apoptosis via Activating the PI3K/Akt/mTOR/VEGF/MMP9 Pathway

Breast cancer is the most common cause of malignancy and cancer-related morbidity and death worldwide that requests effective and safe chemotherapy. Evaluation of metallodrug-based anticancer agents and statins as chemotherapeutics with fewer side effects is a largely unexplored research field. Synthesis and characterization of the ruthenium-fluvastatin complex were achieved using multiple spectroscopic techniques and thus further examined to evaluate its chemotherapeutic prospects in both MDA-MB-231 and MCF-7 cancer lines and eventually in vivo models of DMBA-induced mammary carcinogenesis in rodents. Our studies indicate that the metal and ligand chelation was materialized by the ligand's functional groups of carbonyl (=O) oxygen and hydroxyl (-OH), and the complex has been observed to be crystalline and able to chelate with CT-DNA. The complex was able to reduce cell proliferation and activate apoptotic events in breast carcinoma cell lines MCF-7 and MDA-MB-231. In addition, the complex was able to modify p53 expressions to interfere with apoptosis in the carcinoma of the breast, stimulated by the intrinsic apoptotic path assisted by Bcl2 and Bax in vivo, yet at the same point, controlling the PI3K/Akt/mTOR/VEGF pathway, as obtained from western blotting, correlates with the MMP9-regulated tumor mechanisms. Our research reveals that ruthenium-fluvastatin chemotherapy may disrupt, rescind, or interrupt breast carcinoma progression by modifying intrinsic apoptosis as well as the antiangiogenic cascade, thereby taking the role of a potential candidate in cancer therapy for the immediate future.

Designing Biodegradable and Active Multilayer System by Assembling an Electrospun Polycaprolactone Mat Containing Quercetin and Nanocellulose between Polylactic Acid Films

The design of multilayer systems is an innovative strategy to improve physical properties of biodegradable polymers and introduce functionality to the materials through the incorporation of an active compound into some of these layers. In this work, a trilayer film based on a sandwich of electrospun polycaprolactone (PCL) fibers (PCLé) containing quercetin (Q) and cellulose nanocrystals (CNC) between extruded polylactic acid (PLA) films was designed with the purpose of improving thermal and barrier properties and affording antioxidant activity to packaged foods. PCLé was successfully electrospun onto 70 µm-thick extruded PLA film followed by the assembling of a third 25 µm-thick commercial PLA film through hot pressing. Optical, morphological, thermal, and barrier properties were evaluated in order to study the effect of PCL layer and the addition of Q and CNC. Bilayer systems obtained after the electrospinning process of PCL onto PLA film were also evaluated. The release of quercetin from bi- and trilayer films to food simulants was also analyzed. Results evidenced that thermal treatment during thermo-compression melted PCL polymer and resulted in trilayer systems with barrier properties similar to single PLA film. Quercetin release from bi- and trilayer films followed a similar profile, but achieved highest value through the addition of CNC.

Iron (III)-Quercetin Complex: Synthesis, Physicochemical Characterization, and MRI Cell Tracking toward Potential Applications in Regenerative Medicine

In cell therapy, contrast agents T1 and T2 are both needed for the labeling and tracking of transplanted stem cells over extended periods of time through magnetic resonance imaging (MRI). Importantly, the metal-quercetin complex via coordination chemistry has been studied extensively for biomedical applications, such as anticancer therapies and imaging probes. Herein, we report on the synthesis, characterization, and labeling of the iron (III)-quercetin complex, "IronQ," in circulating proangiogenic cells (CACs) and also explore tracking via the use of a clinical 1.5 Tesla (T) MRI scanner. Moreover, IronQ had a paramagnetic T1 positive contrast agent property with a saturation magnetization of 0.155 emu/g at 1.0 T and longitudinal relaxivity (r1) values of 2.29 and 3.70 mM-1s-1 at 1.5 T for water and human plasma, respectively. Surprisingly, IronQ was able to promote CAC growth in conventional cell culture systems without the addition of specific growth factors. Increasing dosages of IronQ from 0 to 200 μg/mL led to higher CAC uptake, and maximum labeling time was achieved in 10 days. The accumulated IronQ in CACs was measured by two methodologies, an inductively coupled plasma optical emission spectrometry (ICP-EOS) and T1-weighted MRI. In our research, we confirmed that IronQ has excellent dual functions with the use of an imaging probe for MRI. IronQ can also act as a stimulating agent by favoring circulating proangiogenic cell differentiation. Optimistically, IronQ is considered beneficial for alternative labeling and in the tracking of circulation proangiogenic cells and/or other stem cells in applications of cell therapy through noninvasive magnetic resonance imaging in both preclinical and clinical settings.

Unraveling the anti-influenza effect of flavonoids: Experimental validation of luteolin and its congeners as potent influenza endonuclease inhibitors

The biological effects of flavonoids on mammal cells are diverse, ranging from scavenging free radicals and anti-cancer activity to anti-influenza activity. Despite appreciable effort to understand the anti-influenza activity of flavonoids, there is no clear consensus about their precise mode-of-action at a cellular level. Here, we report the development and validation of a screening assay based on AlphaScreen technology and illustrate its application for determination of the inhibitory potency of a large set of polyols against PA N-terminal domain (PA-Nter) of influenza RNA-dependent RNA polymerase featuring endonuclease activity. The most potent inhibitors we identified were luteolin with an IC₅₀ of 72 ± 2 nM and its 8-C-glucoside orientin with an IC₅₀ of 43 ± 2 nM. Submicromolar inhibitors were also evaluated by an in vitro endonuclease activity assay using single-stranded DNA, and the results were in full agreement with data from the competitive AlphaScreen assay. Using X-ray crystallography, we analyzed structures of the PA-Nter in complex with luteolin at 2.0 Å resolution and quambalarine B at 2.5 Å resolution, which clearly revealed the binding pose of these polyols coordinated to two manganese ions in the endonuclease active site. Using two distinct assays along with the structural work, we have presumably identified and characterized the molecular mode-of-action of flavonoids in influenza-infected cells.

Decrypting the Molecular Mechanistic Pathways Delineating the Chemotherapeutic Potential of Ruthenium-Phloretin Complex in Colon Carcinoma Correlated with the Oxidative Status and Increased Apoptotic Events

To explore fresh strategies in colorectal cancer (CRC) chemotherapy, we evaluated the capability of the ruthenium-phloretin complex in exterminating colon cancer by effectively addressing multiple apoptotic mechanisms on HT-29 cancer cells together with an animal model of colorectal cancer activated by 1,2-dimethylhydrazine and dextran sulfate sodium. Our current approach offers tangible evidence of the application of the ruthenium-phloretin complex in future chemotherapy. The complex triggers intrinsic apoptosis triggered by p53 and modulates the Akt/mTOR pathway along with other inflammatory biomarkers. The ruthenium-phloretin complex has been synthesized and successfully characterized by numerous spectroscopic methodologies accompanied by DPPH, FRAP, and ABTS assays assessing its antioxidant potential. Studies conducted in human cell lines revealed that the complex improved levels of p53 and caspase-3 while diminishing the activities of VEGF and mTOR, triggers apoptosis, and induces fragmentation of DNA in the HT-29 cells. Toxicity studies were conducted to identify the therapeutic doses of the novel complex in animal models. The outcomes of the in vivo report suggest that the complex was beneficial in repressing multiplicity of aberrant crypt foci as well as hyperplastic lesions and also promoted increased levels of CAT, SOD, and glutathione. In addition, the ruthenium-phloretin complex was able to control cell proliferation and boosted apoptotic outbursts in cancer cells associated with the increase in cellular response towards Bax while diminishing responses towards Bcl-2, NF-κB, and MMP-9. Our observations from the experiments deliver testament that the ruthenium-phloretin complex has the potential to act as a promising chemotherapeutic agent in colorectal cancer because it can affect the growth of ACF and hyperplastic abrasions in the colon tissues by evoking cell death.

Design of a Multifunctional Biomaterial Inspired by Ancient Chinese Medicine for Hair Regeneration in Burned Skin

In deep burn injuries, the dermis of the skin is often severely damaged, and hair follicles are also lost and lose the potential for regeneration. Therefore, the development of wound dressings that promote hair follicle regeneration has important clinical significance. In this study, inspired by an ancient Chinese medicine prescription, a novel fibrous membrane (P/Qu/Cup; P, PCL; Qu, quercetin; Cup, cuprorivaite, CaCuSi₄O₁₀) containing quercetin-copper (Qu-Cu) chelates was fabricated by using quercetin and a highly bioactive bioceramic (CaCuSi₄O₁₀) incorporated in PCL/gelatin electrospun fibers. The fibrous membrane can effectively release Qu and Cu ions to induce proliferation, migration, and differentiation of skin and hair follicle related cells, and the Qu, Cu ions, and Si ions released from the composite membrane revealed synergistic activity to stimulate hair follicle regeneration and wound healing. Our study demonstrated that the analysis of the common components in ancient Chinese prescription is an effective approach to design novel bioactive materials for regenerative medicine.

Theranostic Quercetin Nanoparticle for Treatment of Hepatic Fibrosis

The progression of hepatic fibrosis can lead to cirrhosis and hepatic failure, but the development of antifibrotic drugs have faced the challenges of poor effectiveness and targeted specificity. Herein, a theranostic strategy was carried to encapsulate a natural medicine (Quercetin, QR) into hepatitis B core (HBc) protein nanocages (NCs) for imaging and targeted treatment of hepatic fibrosis. It was noted that nanoparticles (RGD-HBc/QR) with surface-displayed RGD targeting ligand exhibit a rather high selectivity toward activated HSCs via the binding affinity with integrin α_vβ₃, and an efficient inhibition of proliferation and activation of hepatic stellate cells (HSCs) in vitro and in vivo. Once encapsulated in quercetin-gadolinium complex and/or labeled with the NIR fluorescent probes (Cy5.5), the resulting nanoparticles (RGD-HBc/QGd) show great potential as NIR fluorescent and magnetic resonance imaging contrast agents for hepatic fibrosis in vivo. Therefore, the multifunctional integrin-targeted nanoparticles could selectively deliver QR to the activated HSCs, and may provide an effective antifibrotic theranostic strategy.

Antioxidant, antimicrobial and cytotoxic activities of gold nanoparticles capped with quercetin

In the present work, we report the antioxidant, antimicrobial and cytotoxic activities of quercetin-capped gold nanoparticles (AuNPsQct). The synthesis of AuNPsQct was confirmed by UV-Vis spectroscopy, FTIR and transmission electron microscopy (TEM) analyses. The FTIR spectrum showed the integrity of the quercetin molecules on the nanoparticle surface. The TEM images showed sizes less than 100 nm and a slight spherical shape. The electrostatic stability was confirmed by the zeta potential method. The antioxidant activity of quercetin, evaluated by DPPH, ABTS and nitric oxide free radical scavenging methods, was preserved in the gold nanoparticles, furthermore quercetin-capped gold nanoparticles (IR₅₀ 0.37 µg/mL) demonstrated a higher antioxidant activity than free quercetin (IR₅₀ 0.57 µg/mL) by nitric oxide free radical scavenging method. Strong antifungal activity was observed for Aspergillus fumigatus with concentrations ranging from 0.1 to 0.5 mg/mL. The nanoparticles with quercetin did not exhibit cytotoxicity to human fibroblasts (L929 cells). In conclusion, these results suggest that AuNPsQct, produced by cost-effective method, can act as a promising candidate for different medical applications.

Potentiating apoptosis and modulation of p53, Bcl2, and Bax by a novel chrysin ruthenium complex for effective chemotherapeutic efficacy against breast cancer

Breast cancer is the most frequent cause of cancer in women. In the current study, transition metal ruthenium was complexed with flavonoid chrysin to evaluate the chemotherapeutic potential of this compound in Michigan Cancer Foundation-7 (MCF-7) human mammary cancer cell line and 7,12-dimethylbenz(α)anthracene-induced mammary cancer in female Sprague-Dawley rats. The characterizations of the complex were accomplished through UV-visible, NMR, IR, Mass spectra, and XRD techniques and antioxidant activity was assessed by DPPH, FRAP, and ABTS methods. In vitro studies included cell viability, cell cycle analysis, DNA fragmentation, and marker analysis by western blot analysis and found that complex treatment suppressed cell growth-induced cell cycle arrest and enhanced the induction of apoptosis in cancer cells. Moreover, complex treatment modulated signaling pathways including mTOR, VEGF, and p53 in the MCF-7 cells. Acute and subacute toxicity was performed in rats to determine the therapeutic doses. Breast cancer in rats was initiated by the administration of 7,12-dimethylbenz(α)anthracene (0.5 mg/100 g body weight) via single tail vein injection. The histopathological analysis after 24 weeks of carcinogenesis study depicted substantial repair of hyperplastic lesions. Immunohistochemical analysis revealed upregulation of Bax and p53 and downregulation of Bcl2 proteins and TUNEL assay showed an increase in apoptotic index in ruthenium-chrysin-treated groups as compared to the carcinogen control. Our findings from the in vitro and in vivo study support the continued investigation of ruthenium-chrysin complex possesses a potential chemotherapeutic activity against breast cancer and was efficient in reducing hyperplastic lesions in the mammary tissues of rats by inducing apoptosis.

Synthesis, Characterization, and Biomedical Applications of an Alkylated Quercetin-Gadolinium Complex

Flavonoids and their derivatives have been extensively studied for their pharmaceutical applications due to their antioxidant and anti-inflammatory properties. The coordination complexes of several flavonoids have demonstrated DNA binding ability that can confer anticancer properties. The structure of the flavonoid has a pronounced influence on its pharmacological properties. Herein we report the synthesis and characterization of alkylated quercetin and its complex with gadolinium. The structure of the complex was confirmed using spectroscopic techniques. The ability of the gadolinium-alkylated quercetin complex to serve as a magnetic contrast agent was compared with gadolinium-quercetin complex. The quercetin-gadolinium complex was found to exhibit better contrast property with a relaxivity of 0.2952 μg mL^-1 s^-1 when compared to the gadolinium complex of alkylated quercetin. This difference primarily arises due to the greater hydrophobicity of the alkylated quercetin complex that restricts access of water. However, the alkylated quercetin was found to exhibit better enzyme mimic activity as the metal ion served as a redox center that enabled quantification of hydrogen peroxide in the concentration range 50-450 μM within 5 s with a sensitivity of 64 nA/μM and limit of detection of 7.3 μM. The better sensing performance of the alkylated quercetin-gadolinium complex, reported here for the first time, when compared to quercetin-gadolinium complex can be attributed to the enhanced electroactive area on the working electrode.

Differential Effects of Quercetin and Two of Its Derivatives, Isorhamnetin and Isorhamnetin-3-glucuronide, in Inhibiting the Proliferation of Human Breast-Cancer MCF-7 Cells

Quercetin (Que) has consistently been reported to be useful cytotoxic compound in vivo and in vitro, but little is known on its metabolites. Here, we examined and compared the cytotoxic effects of Que and its water-soluble metabolites, isorhamnetin (IS) and isorhamnetin-3-glucuronide (I3G), in human breast-cancer MCF-7 cells to uncover their tumor-inhibitory mechanisms and structure-function relationships. The results showed that Que, IS, and I3G could dose-dependently inhibit the growth of MCF-7 cells, and the cytotoxic effect was ranked as Que > IS > I3G. Furthermore, Que, IS, and I3G mediated cell-cycle arrest principally in S phase, followed by a decrease in the number of cells in G0/G1 and G2/M; moreover, 70.8, 68.9, and 49.8% of MCF-7 tumor cells entered early-phase apoptosis when treated with 100 μM Que, IS, and I3G for 48 h, respectively. Moreover, induction of apoptosis by Que, IS, and I3G was accompanied by the marginal generation of intracellular reactive oxygen species (ROS). Given these results, Que, IS, and I3G possess strong cytotoxic effects through an ROS-dependent apoptosis pathway in MCF-7 cells.

Vanadium quercetin complex attenuates mammary cancer by regulating the P53, Akt/mTOR pathway and downregulates cellular proliferation correlated with increased apoptotic events

Flavonoid metal ion complexes have been deliberated in recent years and are considered as a new class of medicinal agents with enhanced therapeutic activity and low toxicity. Our study deals with chemotherapeutic effects of vanadium, when coordinated with the flavonoid quercetin on a defined model of chemically induced rat mammary carcinogenesis in vivo and on human breast cancer cell line MCF-7 in vitro. The characterization of the complex was achieved through UV-Visible, IR, and Mass spectra and antioxidant activity was assessed by DPPH, FRAP and ABTS methods. In vitro studies established that the complex upregulated the expressions of p53, Caspase 3 and 9, whereas down regulating Akt, mTOR and VEGF expressions and also induced apoptosis and DNA fragmentation in a dose dependent manner. Acute and Sub-acute toxicity was performed to determine safe doses. 7,12-Dimethylbenz(α)anthracene (0.5 mg/100 g body weight) was used for induction of breast cancer in female Sprague-Dawley rats via single tail vein injection. The histopathological analysis after 24 weeks of carcinogenesis study depicted substantial repair of hyperplastic lesions. TUNEL assay showed an increase in apoptotic index (0.14 ± 0.03; 0.15 ± 0.01) in vanadium-quercetin treated groups as compared to the carcinogen control (0.02 ± 0.01) along with upregulation of Bcl-2 and downregulation of Bax and p53. Immunohistochemical analysis also exhibited decrease in cell proliferation in the vanadium-quercetin treated groups (11.3 ± 0.12; 11.8 ± 0.10). Thus, results from both in vivo and in vitro studies revealed that vanadium-quercetin complex could be a potential candidate for development of approved drug for breast cancer in the near future.

Deciphering the biochemical and molecular mechanism underlying the in vitro and in vivo chemotherapeutic efficacy of ruthenium quercetin complex in colon cancer

Flavonoids are the most investigated phytochemicals due to their pharmacological and therapeutic activities. Their ability to chelate with metal ions has resulted in the emergence of a new category of molecules with a broader spectrum of pharmacological activities. In this study, the ruthenium quercetin complex has been synthesized and anticancer activity has been evaluated on a well-defined model of DMH followed by DSS induced rat colon cancer and on human colon cancer cell line HT-29. The characterizations accomplished through UV-visible, NMR, IR, Mass spectra and XRD techniques, and antioxidant activity was assessed by DPPH, FRAP, and ABTS methods. In vitro study confirmed that the complex increased p53 expression, reduced VEGF and mTOR expression, apoptosis induction, and DNA fragmentation in the HT-29 cells. Acute and subacute toxicity study was also assessed and results from in vivo study revealed that complex was efficient to suppress ACF multiplicity and hyperplastic lesions and elevated the CAT, SOD, and glutathione levels. Furthermore, the complex was found to decrease cell proliferation and increased apoptotic events in tumor cells correlates upregulation of p53 and Bax and downregulation of Bcl2 expression. Our findings from the in vitro and in vivo study support the continued investigation of ruthenium quercetin complex possesses a potential chemotherapeutic activity against colon cancer and was efficient in reducing ACF multiplicity, hyperplastic lesions in the colon tissues of rats by inducing apoptosis.

Different antitumor effects of quercetin, quercetin-3′-sulfate and quercetin-3-glucuronide in human breast cancer MCF-7 cells

This study was designed to investigate the tumor-inhibitory effects of quercetin (Que) and its water-soluble metabolites, quercetin-3′-sulfate (Q3′S) and quercetin-3-glucuronide (Q3G), as well as to make the molecular mechanism and structure-antitumor relationship clear.