A minireview of quercetin: from its metabolism to possible mechanisms of its biological activities

Multifunctional quercetin-hordein-chitosan nanoparticles: A non-antibiotic strategy for accelerated wound healing

Wound infections are a growing public health issue, worsened by drug-resistant strains. Quercetin (Que) has shown anti-inflammatory, antioxidant, and antimicrobial properties, but its limited bioavailability hinders therapeutic use. This study introduces a multifunctional self-assembly nanoplatform, QHCNPs, encapsulating quercetin with hordein/chitosan to enhance stability and bioavailability. Transmission electron microscopy and particle size analysis revealed that QHCNPs are spherical structures with a diameter of 435.5 ± 2.9 nm and a Zeta potential of +11.0 mV. QHCNPs demonstrated excellent stability, low cytotoxicity, and MIC values of 512 ppm against Staphylococcus aureus (S. aureus) and 256 ppm against methicillin-resistant Staphylococcus aureus (MRSA). In a bacterial wound model, QHCNPs outperformed quercetin alone by accelerating wound healing, eliminating bacteria, reducing inflammatory markers, scavenging reactive oxygen species (ROS), and promoting collagen and blood vessel regeneration. These results establish QHCNPs as a promising non-antibiotic therapy for treating drug-resistant wound infections, supporting further exploration for clinical applications.

Green development strategy for efficient quercetin- loaded whey protein complex: Focus on quercetin loading characteristics, component interactions, stability, antioxidant, and in vitro digestive properties

This study aimed to develop a quercetin-loaded whey protein complex using pH-induced co-assembly for the intestinal-targeted delivery of quercetin. The investigation focused on quercetin loading capacity, formation mechanism, stability, antioxidant activity, and in vitro digestive properties of the complex. The results indicated that the stable complex was obtained at a quercetin-to-protein mass ratio of 1:20, exhibiting a high encapsulation efficiency (96.4 %) and loading capacity (4.6 %). Interaction studies revealed that quercetin binds to whey protein via hydrophobic interactions and hydrogen bonding, forming an irregular layered structure. Stability analysis demonstrated that the complex possesses high ionic and thermal stability. The antioxidant capacity of quercetin was significantly enhanced by complex encapsulation. In vitro digestion studies showed that the complex could pass through the gastrointestinal tract smoothly and effectively improve the bio-accessibility of quercetin. These findings provide a theoretical basis for the application of whey protein-based quercetin delivery systems in the functional food field.

Zein and Trimethyl Chitosan-Based Core-Shell Nanoparticles for Quercetin Oral Delivery to Enhance Absorption by Paracellular Pathway in Obesity Mice

Quercetin as a flavonoid polyphenol in nature has shown great anti-obesity effects. Due to its poor stability in chemical structure and low intestinal absorption, the in vivo bioavailability of quercetin is considered to be the main challenge for applications. To achieve the oral quercetin administration, chitosan was successfully trimethylated (TMC) to coat the quercetin-loaded zein nanoparticles (Zein-Q), which were designed as the core-shell structure for enhancing the intestinal absorption in this study. TMC-Zein-Q was demonstrated to protect quercetin from degradation and showed the sustained-release effect in an in vitro drug release experiment. The nanoparticles were found to reversibly open tight junctions between intestinal epithelial cells and help to increase quercetin uptake via the paracellular pathway in Caco-2 cells. In addition, the delivery system also showed stronger intestinal permeability and mucoadhesion in vivo, which improved the bioavailability of quercetin in cellular and animal experiments. After 10 weeks of intervention, TMC-Zein-Q could effectively suppress weight gain, improve serum lipid levels, and ameliorate hepatic steatosis and glucose tolerance in high-fat diet (HFD) mice by mediating the AMPK pathway. Consequently, this work successfully constructed TMC-Zein-Q for oral quercetin delivery, providing a novel and feasible strategy for the treatment of obesity via the oral route.

Herbal bioactive-loaded biopolymeric formulations for wound healing applications

Recent advancements in wound healing technologies focus on incorporating herbal bioactives into biopolymeric formulations. A biocompatible matrix that promotes healing is provided by biopolymeric wound dressings. These dressings use components such as ulvan, hyaluronic acid, starch, cellulose, chitosan, alginate, gelatin, and pectin. These natural polymers assist in three crucial processes, namely, cell adhesion, proliferation, and moisture retention, all of which are necessary for effective wound repair. Curcumin, quercetin, Aloe vera, Vinca alkaloids, and Centella asiatica are some of the herbal bioactives that are included in biopolymeric formulations. They have powerful anti-inflammatory, antibacterial, and antioxidant activities. Chitosan, cellulose, collagen, alginate, and hyaluronic acid are some of the biopolymers that have shown promise in clinical trials for wound healing. These trials have also confirmed the safety and functional performance of these materials. Their recent advancements in wound care can be understood by the increasing number of patents linked to these formulations. These innovative dressings improve healing outcomes in acute and chronic wounds while minimizing adverse effects by incorporating biopolymers with herbal bioactives in an efficient manner. This review emphasizes that the development of next-generation wound care products can be facilitated via the integration of natural materials and bioactive substances.

Role of Phytonutrients in the Prevention and Treatment of Chronic Diseases: A Concrete Review

Delving into the intricate role of phytonutrients is paramount to effectively preventing and treating chronic diseases. Phytonutrients are "plant-based nutrients" that positively affect human health. Phytonutrients perform primary therapeutic functions in the management and treatment of various diseases. It is reported that different types of pathogenesis occur due to the excessive production of oxidants (reactive nitrogen species and reactive oxygen species). The literature shows that a higher intake of fruits, vegetables, and other plant-based food is inversely related to treating different chronic diseases. Due to many phytonutrients (antioxidants) in fruits, vegetables, and other medicinal plants, they are considered major therapeutic agents for various diseases. The main purpose of this review is to summarize the major phytonutrients involved in preventing and treating diseases. Fourteen major phytonutrients are discussed in this review, such as polyphenols, anthocyanin, resveratrol, phytosterol (stigmasterol), flavonoids, isoflavonoids, limonoids, terpenoids, carotenoids, lycopene, quercetin, phytoestrogens, glucosinolates, and probiotics, which are well-known for their beneficial effects on the human body and treatment of different pathological conditions. It is concluded that phytonutrients play a major role in the prevention and treatment of diabetes mellitus, obesity, hypertension, cardiovascular disorders, other types of cancers, neurological disorders, age-related diseases, and inflammatory disorders and are also involved in various biological activities.

Evaluating binding behavior of quercetin to human serum albumin and calf thymus DNA: Insights from molecular dynamics, spectroscopy, and apoptotic pathway regulation

In this work, we sought to apprehend quercetin binding affinity and its interaction behavior in complex with human serum albumin (HSA) and calf thymus DNA (ctDNA) through multi spectroscopy and molecular dynamics and also evaluated its effects on colorectal cancer. The binding constants of ctDNA-quercetin and HSA-quercetin complexes at 298 K, which were calculated to be (2.67 ± 0.04) × 103 M-1 and (4.77 ± 0.05) × 104 M-1 respectively, denoted the strong binding of quercetin with ctDNA and HSA. The Ksv and Kb values decrease with increasing temperature, indicating that the quenching of HSA and ctDNA in the presence of quercetin is caused by the combined dynamic and static effects. The obtained thermodynamic parameters for the ctDNA-quercetin interaction represented the existence of electrostatic forces (ΔH0 < 0 and ΔS0 > 0), and the thermodynamic parameters of HSA-quercetin complex disclose the dominance of hydrogen bonds and van der Waals interactions (ΔH0 < 0 and ΔS0 < 0). Moreover, the interactions were exothermic, as evidenced by the negative ΔH0 value for both interactions. According to molecular docking and MD simulation data, quercetin was capable of placing into the site 1 of HSA and forming stable interaction plus this ligand tended to unwind DNA's strands as an intercalator ligand, which was confirmed by experimental results. The fluorescence competition studies between the two intercalator probes of ethidium bromide (EB) and acridine orange (AO), as well as the effect of ionic strength, proposed the strong tendency of quercetin to exist between the two strands of ctDNA as a sign of its intercalative property. Consequently, quercetin can be assumed as an efficient intercalator ligand carried by HSA with an anticancer property. We also conducted cell viability experiments on HT-29 and SW620 cell lines to validate the anticancer ability of quercetin, and observed its decreasing impact on the cell viability of these two cell lines. Additionally, the outcomes of Real-time qPCR proved its capability to reduce the CXCR4 expression and increase the NKD2 expression in Wnt signaling pathway. Therefore, these facts confirm the inhibiting ability of quercetin towards colorectal cancer growth via the prevention of Wnt pathway and approve its functionality as a potential anticancer agent for this cancer.

Quercetin Prevents Hyperuricemia Associated With Gouty Arthritis by Inactivating the NLRP3/NF-κB Signaling Pathway

Quercetin (QCT) shows great therapeutic potential for hyperuricemia (HUA) associated with gouty arthritis (GA). However, the underlying mechanism of QCT in inhibiting the progression of HUA and GA remains unclear. HUA mouse model was established by injection of oteracil potassium (OXO) combined with ethambutol (EMB). The GA mouse model was established by intraarticular injection of sodium urate (MSU). MSU-induced HK-2 cells as well as lipopolysaccharide (LPS) and MSU-induced THP-1/M0 macrophages were used as cell models. The ankle perimeter of each mouse was measured to evaluate ankle swelling. The study also detected serum levels of uric acid (UA), tumor necrosis factor-α (TNF-α), interleukin (IL)-1β (IL-1β), and IL-6 and analyzed the pathological conditions of synovial tissues and renal tissues. QCT treatment inhibited ankle joint swelling, TNF-α, IL-1β, and IL-6 serum levels as well as UA production in HUA and GA mice. Treatment with QCT inhibited oxidative stress in the renal tissues of HUA and GA mice and MSU-induced HK-2 cells. QCT treatment inhibited the inflammatory response in LPS and MSU-induced THP-1/M0 macrophages. QCT treatment inactivated the NOD-like receptor thermal protein domain associated protein 3 (NLRP3)/nuclear factor kappa-B (NF-κB) pathway. QCT inactivated the NLRP3/NF-κB signaling pathway to prevent HUA associated with GA.

Phytochemical Insights and Therapeutic Potential of Chamaenerion angustifolium and Chamaenerion latifolium

The Chamaenerion genus, particularly Chamaenerion angustifolium and Chamaenerion latifolium, is recognized for its rich phytochemical composition and extensive medicinal properties. These species are abundant in polyphenols, flavonoids, and tannins, which contribute to their potent antioxidant, antimicrobial, and anticancer activities. This review provides a comprehensive analysis of their phytochemical constituents, with an emphasis on how processing methods, including fermentation, influence bioactivity. Notably, fermentation enhances the levels of key bioactive compounds, such as oenothein B, gallic acid, and ellagic acid, thereby increasing their pharmacological potential. Additionally, this review evaluates the biological activities of Chamaenerion species in relation to their chemical composition, while also considering the limitations of current studies, such as the lack of in vivo or clinical trials. The literature for this review was sourced from scientific databases, including PubMed, Scopus, and ScienceDirect, covering research from 2010 to 2024. Future studies should focus on optimizing extraction methods, elucidating synergistic bioactivities, and conducting in-depth clinical trials to validate their efficacy and safety.

A Screen of Plant-Based Natural Products Revealed That Quercetin Prevents Pyroglutamylated Amyloid-β (Aβ3(pE)-42) Uptake in Astrocytes As Well As Resulting Astrogliosis and Synaptic Dysfunction

Two connected histopathological hallmarks of Alzheimer's disease (AD) are chronic neuroinflammation and synaptic dysfunction. The accumulation of the most prevalent posttranslationally modified form of Aβ1-42, pyroglutamylated amyloid-β (Aβ3(pE)-42) in astrocytes is directly linked to glial activation and the release of proinflammatory cytokines that in turn contribute to early synaptic dysfunction in AD. At present, the mechanisms of Aβ3(pE)-42 uptake to astrocytes are unknown and pharmacological interventions that interfere with this process are not available. Here we developed a simple screening assay to identify substances from a plant extract library that prevent astroglial Aβ3(pE)-42 uptake. We first show that this approach yields valid and reproducible results. Second, we show endocytosis of Aβ3(pE)-42 oligomers by astrocytes and that quercetin, a plant flavonol, is effective to specifically block astrocytic buildup of oligomeric Aβ3(pE)-42. Importantly, quercetin does not induce a general impairment of endocytosis. However, it efficiently protects against early synaptic dysfunction following exogenous Aβ3(pE)-42 application.

In vitro and in vivo evidence of the antineoplastic activity of quercetin against endothelial cells transformed by Kaposi's sarcoma-associated herpesvirus G protein-coupled receptor

Quercetin (QUE) is a natural flavonoid with well-known anticancer capabilities, although its effect on viral-induced cancers is less studied. Kaposi's sarcoma (KS) is a viral cancer caused by the human herpesvirus-8, which, during its lytic phase, expresses a constitutively activated viral G protein-coupled receptor (vGPCR) able to induce oncogenic modifications that lead to tumor development. The aim of this work was to investigate the potential effect of QUE on in vitro and in vivo models of Kaposi's sarcoma, developed by transforming endothelial cells with the vGPCR of Kaposi's sarcoma-associated herpesvirus. Initially, the antiproliferative effect of QUE was determined in endothelial cells stably expressing the vGPCR (vGPCR cells), with an IC50 of 30 μM. Additionally, QUE provoked a decrease in vGPCR cell viability, interfered with the cell cycle progression, and induced apoptosis, as revealed by annexin V/PI analysis and caspase-3 activity. The presence of apoptotic bodies and disorganized actin filaments was observed by SEM and phalloidin staining. Furthermore, tumors from vGPCR cells were induced in nude mice, which were treated with QUE (50 or 100 mg/kg/d) resulting in retarded tumor progression and reduced tumor weight. Notably, neither kidney nor liver damage was observed, as indicated by biochemical parameters in serum. In conclusion, this study suggests for the first time that QUE exhibits antineoplastic activity in both in vitro and in vivo models of KS, marking a starting point for further investigations and protocols for therapeutic purpose.

A comprehensive review on anti-allergic natural bioactive compounds for combating food allergy

Food allergy poses a great challenge to food safety and public health worldwide. Currently, clinical symptoms are primarily managed with medications, which can lead to drug resistance, adverse effects, and disruptions in gut flora balance. As a result, there has been a focus on researching safe and effective anti-allergic natural ingredients. This paper provides a comprehensive overview of food allergy mechanisms, methods of assessment of anti-food allergy studies, and a classification of natural substances with anti-allergic properties. It also examines the anti-allergic effects of these substances on food allergies and investigates gut microbiota changes induced by these natural bioactives, highlighting their significance to food allergies.Natural actives with anti-food allergic properties may alleviate allergic reactions through multiple targets and pathways. These mechanisms include promoting a shift in the Th1/Th2 balance, reducting IgE synthesis, preventing cellular degranulation and reducing the release of allergic mediator. The gut environment is closely related to food allergy and there is a significant interaction between the two. By targeting the intestinal flora, we can adopt dietary interventions to effectively address and control food allergies. This provides valuable insights for the future development of functional foods targeting the alleviation of food allergies.

Therapeutic potential and underlying mechanisms of phytoconstituents: emphasizing on resveratol, curcumin, quercetin, berberine, and hesperidin in ulcerative colitis

Ulcerative colitis is a long-term inflammatory colon illness that significantly affects patients quality of life. Traditional medicines and therapies often come with challenges such as side effects, instability, unpredictability, and high costs. This has captured interest in natural products that have huge health benefits. Various natural compounds, including resveratrol, curcumin, quercetin, berberine, and hesperidin demonstrate immunomodulatory and oxido-inflammatory properties inside the gut epithelium, showing potential in managing ulcerative colitis. These compounds attenuate inflammatory mediators, NF-κB, and TLR4 signaling leading to a reduction in the production of inflammation-related cytokines, including TNF-α and IL-6. They also augment the activity of internal defense compounds, including superoxide radical dismutase enzyme and heme oxygenase-1, thereby alleviating oxidative damage. In addition, natural compounds have a profound effect on the endogenous microbiota and thus, support mucosal healing and intercellular barrier integrity. Both experimental and clinical analyses provide evidence that these bioactive compounds may help reduce clinical manifestations, induce and sustain remission, and improve the well-being of individuals suffering from ulcerative colitis. This review seeks to discuss various aspects of natural compounds in the management of ulcerative colitis, including mechanisms, therapeutic prospects, and hurdles, and hence the basis for future research and practice.

An Overview on the Effects of Some Carotenoids on Health: Lutein and Zeaxanthin

PURPOSE OF REVIEW

In this review, the chemical properties, nutritional sources, absorption mechanisms, metabolism, biosynthesis and promising health-related benefits of lutein and zeaxanthin were emphasized and some recommendations for the future studies are suggested.

RECENT FINDINGS

Lutein and zeaxanthin are phytochemical compounds in the carotenoid group and are synthesised only by plants. All mammals get lutein and zeaxanthin into their bodies by consuming plant-based foods. Especially leafy green vegetables, broccoli, pumpkin, cabbage, spinach and egg yolk are rich in lutein and zeaxanthin. Lutein and zeaxanthin have potential health effects by preventing free radical formation, exhibiting protective properties against oxidative damage and reducing oxidative stress. These compounds have neuroprotective, cardioprotective, ophthalmological, antioxidant, anti-inflammatory, anti-cancer, anti-osteoporosis, anti-diabetic, anti-obesity, and antimicrobial effects. The preventive properties of lutein and zeaxanthin against numerous diseases have attracted attention recently. Further clinical trials with large samples are needed to make generalisations in the prevention and treatment of diseases and to determine the appropriate doses and forms of lutein and zeaxanthin.

Inhalable multi-stimulus sensitive curcumin-alginate nanogels for scavenging reactive oxygen species and anti-inflammatory co-ordination to alleviate acute lung injury

Acute lung injury (ALI) is one of the most common and extremely critical clinical conditions, which progresses with an inflammatory response and overproduction of reactive oxygen species (ROS), leading to oxidative damage to the lungs. Curcumin (Cur) has great potential in treating ALI due to its excellent antioxidant and anti-inflammatory effects. In this study, Cur and alginate were cross-linked by zinc ions and intermolecular hydrogen bonding to form an inhalable aqueous nanogel system to overcome Cur's low solubility and bioavailability. Cur-alginate (ZA-Cur) nanogels exhibited superior antioxidant properties and down-regulated inflammation-associated factors in vitro with controlled-release behavior under multi-stimulus conditions such as temperature, pH, and ions. Meanwhile, the nanogels system could effectively scavenge cellular ROS to repair oxidative stress damage. In a mice model of ALI, tracheal nebulised inhalation of ZA-Cur nanogels down-regulated the expression of inflammation-related genes such as TNF-α, IL-1β, and IL-6, as well as modulated MDA content and CAT activity to attenuate oxidative stress injury, showing promising lung-protective effects. In conclusion, this work developed inhalable ZA-Cur nanogels to decelerate the progression of lesions in ALI by scavenging intracellular ROS and alleviating inflammation simultaneously, which may be a promising strategy for treating ALI.

Design strategies of polysaccharide, protein and lipid-based nano-delivery systems in improving the bioavailability of polyphenols and regulating gut homeostasis

Polyphenols are plant secondary metabolites that have attracted much attention due to their anti-inflammatory, antioxidant, and gut homeostasis promoting effects. However, food matrix interaction, poor solubility, and strong digestion and metabolism of polyphenols cause barriers to their absorption in the gastrointestinal tract, which further reduces bioavailability and limits polyphenols' application in the food industry. Nano-delivery systems composed of biocompatible macromolecules (polysaccharides, proteins and lipids) are an effective way to improve the bioavailability of polyphenols. Therefore, this review introduces the construction of biopolymer-based nano-delivery systems and their application in polyphenols, with emphasis on improving the solubility, stability, sustained release and intestinal targeting of polyphenols. In addition, there are possible positive effects of polyphenol-loaded nano-delivery systems on modulating gut microbiota and gut homeostasis, with particular emphasis on modulating intestinal inflammation, metabolic syndrome, and gut-brain axis. It is worth noting that the safety of bio-based nano-delivery systems still need to be further studied. In summary, the application of the bio-based nano-delivery system to deliver polyphenols provides insights for improving the bioavailability of polyphenols and for the treatment of potential diseases in the future.

The bioavailability, absorption, metabolism, and regulation of glucolipid metabolism disorders by quercetin and its important glycosides: A review

Quercetin and its glycosides (QG), vitally natural flavonoid, have been popular for health benefits. However, the absorption and metabolism affect their bioavailability, and the metabolic transformation alters their biological activities. This review systematically summarizes the bioavailability and pathways for the absorption and metabolism of quercetin/QG in vivo and in vitro, the biological activities and mechanism of quercetin/QG and their metabolites in treating glucolipid metabolism are discussed. After oral administration, quercetin/QG are mainly absorbed by the intestine, undergo phase II metabolism in the small intestine and liver to form conjugates and are metabolized into small phenolic acids by intestinal microbiota. Quercetin/QG and their metabolites exert beneficial effects on regulating glucolipid metabolism disorders, including improving insulin resistance, inhibiting lipogenesis, enhancing thermogenesis, modulating intestinal microbiota, relieving oxidative stress, and attenuating inflammation. This review enhances understanding of the mechanism of quercetin/QG regulate glucolipid metabolism and provides scientific support for the development of functional foods.

Quercetin encapsulation and release using rapid CO2-responsive rosin-based surfactants in Pickering emulsions

Emulsion-based delivery systems are extensively employed for encapsulating functional active ingredients, protecting them from degradation, and enhancing bioavailability and release efficiency. Here, a CO2-responsive surfactant synthesized from rosin displays rapid responsiveness to CO2 at room temperature, transitioning reversibly switches between active and inactive states multiple times. The dual tertiary amines on the rosin rigid structure contributes to its CO2 sensitivity. When in its active cationic form, in conjunction with silica nanoparticles, it exhibits desired Pickering emulsification performance across various oil phases. In the Pickering emulsion loaded with quercetin, the encapsulation efficiency and loading efficiency reached 80.50% and 0.69%, respectively, with stability lasting at least 30 days. The system provides robust protection for quercetin against external factors, such as UV and heat, revealing sustained release effects. This study investigated the potential of using rosin-based CO2-responsive surfactants alongside nanoparticles to design stable Pickering emulsion systems for active substance encapsulation and sustained release.

Effect and mechanism of polyphenols containing m-dihydroxyl structure on 2-amino-1-methyl-6-phenylimidazole [4, 5-b] pyridine (PhIP) formation in chemical models and roast pork patties

2-amino-1-methyl-6-phenylimidazole [4, 5-b] pyridine (PhIP) is a prevalent heterocyclic amine (HAA) found in heated processed meat. This study investigated the inhibitory impact of eight different types of polyphenols containing m-dihydroxyl structure on PhIP formation through a chemical model system. The structure-activity relationship and potential sites of action of polyphenols containing m-dihydroxyl structure were also analyzed. Then, the mechanism of inhibiting PhIP formation by kaempferol, naringenin and quercetin was speculated by UPLC-MS. Results showed that 8 kinds of polyphenols containing m-dihydroxyl structure had significant (P < 0.05) inhibition on the formation of PhIP in the chemical model system in a dose-dependent manner. In addition, PhIP was most significantly inhibited by naringenin at the same concentration, followed by kaempferol and quercetin (83.27%, 80.81% and 79.26%, respectively). UPLC-MS results speculated that kaempferol, naringenin, and quercetin formed a new admixture via an electrophilic aromatic substitution reaction with the intermediate product phenylacetaldehyde, preventing the formation of PhIP.

Therapeutic potentials and targeting strategies of quercetin on cancer cells: Challenges and future prospects

BACKGROUND

Every cell in the human body is vital because it maintains equilibrium and carries out a variety of tasks, including growth and development. These activities are carried out by a set of instructions carried by many different genes and organized into DNA. It is well recognized that some lifestyle decisions, like using tobacco, alcohol, UV, or multiple sexual partners, might increase one's risk of developing cancer. The advantages of natural products for any health issue are well known, and researchers are making attempts to separate flavonoid-containing substances from plants. Various parts of plants contain a phenolic compound called flavonoid. Quercetin, which belongs to the class of compounds known as flavones with chromone skeletal structure, has anti-cancer activity.

PURPOSE

The study was aimed at investigating the therapeutic action of the flavonoid quercetin on various cancer cells.

METHODS

The phrases quercetin, anti-cancer, nanoparticles, and cell line were used to search the data using online resources such as PubMed, and Google Scholar. Several critical previous studies have been included.

RESULTS

Quercetin inhibits various dysregulated signaling pathways that cause cancer cells to undergo apoptosis to exercise its anticancer effects. Numerous signaling pathways are impacted by quercetin, such as the Hedgehog system, Akt, NF-κB pathway, downregulated mutant p53, JAK/STAT, G1 phase arrest, Wnt/β-Catenin, and MAPK. There are downsides to quercetin, like hydrophobicity, first-pass effect, instability in the gastrointestinal tract, etc., because of which it is not well-established in the pharmaceutical industry. The solution to these drawbacks in the future is using bio-nanomaterials like chitosan, PLGA, liposomes, and silk fibroin as carriers, which can enhance the target specificity of quercetin. The first section of this review covers the specifics of flavonoids and quercetin; the second section covers the anti-cancer activity of quercetin; and the third section explains the drawbacks and conjugation of quercetin with nanoparticles for drug delivery by overcoming quercetin's drawback.

CONCLUSIONS

Overall, this review presented details about quercetin, which is a plant derivative with a promising molecular mechanism of action. They inhibit cancer by various mechanisms with little or no side effects. It is anticipated that plant-based materials will become increasingly relevant in the treatment of cancer.

Targeting Gut Microbiota with Probiotics and Phenolic Compounds in the Treatment of Atherosclerosis: A Comprehensive Review

Atherosclerosis (AS) is a chronic inflammatory vascular disease. Dysregulated lipid metabolism, oxidative stress, and inflammation are the major mechanisms implicated in the development of AS. In addition, evidence suggests that gut dysbiosis plays an important role in atherogenesis, and modulation of the gut microbiota with probiotics and phenolic compounds has emerged as a promising strategy for preventing and treating AS. It has been shown that probiotics and phenolic compounds can improve atherosclerosis-related parameters by improving lipid profile, oxidative stress, and inflammation. In addition, these compounds may modulate the diversity and composition of the gut microbiota and improve atherosclerosis. The studies evaluated in the present review showed that probiotics and phenolic compounds, when consumed individually, improved atherosclerosis by modulating the gut microbiota in various ways, such as decreasing gut permeability, decreasing TMAO and LPS levels, altering alpha and beta diversity, and increasing fecal bile acid loss. However, no study was found that evaluated the combined use of probiotics and phenolic compounds to improve atherosclerosis. The available literature highlights the synergistic potential between phenolic compounds and probiotics to improve their health-promoting properties and functionalities. This review aims to summarize the available evidence on the individual effects of probiotics and phenolic compounds on AS, while providing insights into the potential benefits of nutraceutical approaches using probiotic strains, quercetin, and resveratrol as potential adjuvant therapies for AS treatment through modulation of the gut microbiota.

Quercetin in semen extender curtails reactive oxygen and nitrogen species and improves functional attributes of cryopreserved buck semen

Cryopreservation of goat spermatozoa is challenging due to several factors, including one of the most essential, i.e., oxidative stress. It is particularly essential in goat semen due to its scanty ejaculate volume and high sperm concentration. This leaves a narrow sperm-to-seminal plasma ratio owing to marginal antioxidant support; moreover, semen extension further dilutes the antioxidant level, leading to an imbalance of oxidant-antioxidant equilibrium. The present study aimed to evaluate the effect of quercetin on curtailing oxidative stress and its reflection on the post-thaw survivability and membrane integrity of goat spermatozoa. For this study, six bucks were selected. Six ejaculates from each buck totaling 36 ejaculates were collected, which were then split into five parts; furthermore, each part was added with a semen extender having a particular concentration of additive. Group C without quercetin and T1 containing Vitamin E at 3 mmol/mL were considered the control and positive control respectively, whereas T2, T3, and T4 contain 10, 20, and 30 μmol/mL of Quercetin respectively. The final sperm concentration of each group was kept at 200 × 106 spermatozoa/mL. All groups were subjected to equilibration at 4 °C for 4 h, then filled in French mini (0.25 mL) straws, followed by sealing and cryopreservation. Samples after 72 h of cryopreservation were subjected to evaluation of plasma membrane integrity and viability through staining, acrosomal integrity, and mitochondrial membrane activity through flow cytometry. Evaluation of sperm kinematics as well as the oxidant-antioxidant status of sperm (ROS and nitric oxide) and seminal plasma (SOD, CAT, GPx, FRAP, and lipid peroxidation through MDA estimation) were also carried out. Quercetin, when supplemented at 20 μmol/mL in buck semen extender, significantly (p < 0.01) improved cryopreserved sperm functions in terms of plasma membrane integrity, viability, acrosomal integrity, mitochondrial membrane activity, and sperm kinematics of buck semen. Similarly, Quercetin supplementation at 20 μmol/mL significantly reduced reactive oxygen and nitrogen species (RONS) in sperm and improved the antioxidant status of seminal plasma, which was indicated by reduced oxidative damage and improved the antioxidant status of buck semen. In conclusion, Quercetin at 20 μmol/mL reduced oxidative stress, improved semen antioxidant status, and improved sperm membranes integrity and kinematics.

The role of polyphenols in modulating mitophagy: Implications for therapeutic interventions

This review rigorously assesses the burgeoning research into the role of polyphenols in modulating mitophagy, an essential cellular mechanism for the targeted removal of impaired mitochondria. These natural compounds, known for their low toxicity, are underscored for their potential in therapeutic strategies against a diverse array of diseases, such as neurodegenerative, cardiovascular, and musculoskeletal disorders. The analysis penetrates deeply into the molecular mechanisms whereby polyphenols promote mitophagy, particularly by influencing crucial signaling pathways and transcriptional regulators, including the phosphatase and tensin homolog (PTEN) induced putative kinase 1 (PINK1)/parkin and forkhead box O3 (FOXO3a) pathways. Noteworthy discoveries include the neuroprotective properties of resveratrol and curcumin, which affect both autophagic pathways and mitochondrial dynamics, and the pioneering integration of polyphenols with other natural substances to amplify therapeutic effectiveness. Furthermore, the review confronts the issue of polyphenol bioavailability and emphasizes the imperative for clinical trials to corroborate their therapeutic viability. By delivering an exhaustive synthesis of contemporary insights and recent advancements in polyphenol and mitophagy research, this review endeavors to catalyze additional research and foster the creation of innovative therapeutic modalities that exploit the distinctive attributes of polyphenols to manage and prevent disease.

Antibacterial, Anti-Inflammatory, and Antioxidant Cotton-Based Wound Dressing Coated with Chitosan/Cyclodextrin-Quercetin Inclusion Complex Nanofibers

Quercetin, recognized for its antioxidant, anti-inflammatory, and antibacterial properties, faces limited biomedical application due to its low solubility. Cotton, a preferred wound dressing material over synthetic ones, lacks inherent antibacterial and wound-healing attributes and can benefit from quercetin features. This study explores the potential of overcoming these challenges through the inclusion complexation of quercetin with cyclodextrins (CDs) and the development of a nanofibrous coating on a cotton nonwoven textile. Hydroxypropyl-beta-cyclodextrin (HP-β-CD) and hydroxypropyl-gamma-cyclodextrin (HP-γ-CD) formed inclusion complexes of quercetin, with chitosan added to enhance antibacterial properties. Phase solubility results showed that inclusion complexation can enhance quercetin solubility up to 20 times, with HP-γ-CD forming a more stable inclusion complexation compared with HP-β-CD. Electrospinning of the nanofibers from HP-β-CD/Quercetin and HP-γ-CD/Quercetin aqueous solutions without the use of a polymeric matrix yielded a uniform, smooth fiber morphology. The structural and thermal analyses of the HP-β-CD/Quercetin and HP-γ-CD/Quercetin nanofibers confirmed the presence of inclusion complexes between quercetin and each of the CDs (HP-β-CD and HP-γ-CD). Moreover, HP-β-CD/Quercetin and HP-γ-CD/Quercetin nanofibers showed a near-complete loading efficiency of quercetin and followed a fast-releasing profile of quercetin. Both HP-β-CD/Quercetin and HP-γ-CD/Quercetin nanofibers showed significantly higher antioxidant activity compared to pristine quercetin. The HP-β-CD/Quercetin and HP-γ-CD/Quercetin nanofibers also showed antibacterial activity, and with the addition of chitosan in the HP-γ-CD/Quercetin system, the Chitosan/HP-γ-CD/Quercetin nanofibers completely eliminated the investigated bacteria species. The nanofibers were nontoxic and well-tolerated by cells, and exploiting the quercetin and chitosan anti-inflammatory activities resulted in the downregulation of IL-6 and NO secretion in both immune as well as regenerative cells. Overall, CD inclusion complexation markedly enhances quercetin solubility, resulting in a biofunctional antioxidant, antibacterial, and anti-inflammatory wound dressing through a nanofibrous coating on cotton textiles.

Acellular spinal cord scaffold containing quercetin-encapsulated nanoparticles plays an anti-inflammatory role in functional recovery from spinal cord injury in rats

Inflammatory responses play a crucial role in the pathophysiology of spinal cord injury (SCI) and developing new approaches to establish an anti-inflammatory environment for the promotion of neuroregeneration holds promise as a potential approach. In this study, our aim was to investigate the potential of combining an acellular spinal cord scaffold (ASCS) with quercetin-loaded bovine serum albumin (Qu/BSA) nanoparticles (NPs) for the treatment of SCI. The ASCS was prepared using physical and chemical methods, while the Qu/BSA NPs were prepared through a desolvation technique. The NPs exhibited favorable characteristics, including a mean size of 203 nm, a zeta potential of -38, and an encapsulation efficiency of 96%. Microscopic evaluation confirmed the successful distribution of NPs on the walls of ASCS. Animal studies revealed that Qu/BSA NPs group exhibited a significant decrease in NLRP3, ASC, and Casp1 gene expression compared to the SCI group (p < 0.0001). The findings indicated a significant decrease in the NLRP3, ASC, and Casp1 protein level between the Qu/BSA/ASCS group and the SCI group (p < 0.0001). Moreover, treatment with ASCS containing either blank BSA (B/BSA) NPs or Qu/BSA NPs effectively promoted functional recovery via increasing the amount of nestin- and glial fibrillary acidic protein (GFAP)-positive cells in the site of injury. Notably, Qu/BSA/ASCS exhibited superior outcomes compared to B/BSA/ASCS. Overall, the combination of ASCS with the Qu delivery system presents a promising therapeutic approach for SCI by inhibiting inflammatory responses and promoting neuroregeneration, leading to the restoration of motor function in animals. This study demonstrates the potential of utilizing biomaterials and NPs to enhance the effectiveness of SCI treatment.

Pharmacological mechanism of quercetin in the treatment of colorectal cancer by network pharmacology and molecular simulation

Colorectal cancer is a serious threat to people's life due to its high incidence and high mortality. Quercetin can effectively treat colorectal carcinoma (CRC), but its exact mechanism of action is still unclear. Then quercetin-related target genes were obtained from Swiss Target Prediction database and Similarity Ensemble Approach (SEA) database, and CRC-related target genes were obtained from GeneCards database, respectively. Common target genes were obtained by FunRich software. String software was used to construct a protein-protein interaction (PPI) network. R package was used for gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. Molecular docking, molecular dynamics (MD) simulation and post-dynamics simulation were used to explore the binding stability of quercetin to key targets. In total, 103 and 141 target information of quercetin were obtained from the Swiss Target Prediction database and SEA database, respectively. 1,649 CRC-related genes were obtained from GeneCards database. FunRich software was used to draw venny map and obtain 36 intersection targets of quercetin and CRC. String software was used to construct the PPI network. The core genes were AKT1, EGFR, MMP9, KDR, MET and PTK2. There were 532 items related to biological processes, 14 items related to cellular components, and 43 items related to molecular functions among the key target GO enrichment items. KEGG enrichment pathways of key targets involved cancer pathways, PI3K-Akt signal pathway, etc. The results of molecular docking, MD simulation and post-dynamics simulation showed they had a good affinity and formed a stable effect. So quercetin may play an important role in the treatment of CRC by acting on AKT1, EGFR, MMP9, KDR, MET and PTK2 to affect the development of CRC.Communicated by Ramaswamy H. Sarma.

Transgenerational hormesis in healthy aging and antiaging medicine from bench to clinics: Role of food components

Neurodegenerative diseases have multifactorial pathogenesis, mainly involving neuroinflammatory processes. Finding drugs able to treat these diseases, expecially because for most of these diseases there are no effective drugs, and the current drugs cause undesired side effects, represent a crucial point. Most in vivo and in vitro studies have been concentrated on various aspects related to neurons (e.g. neuroprotection), however, there has not been focus on the prevention of early stages involving glial cell activation and neuroinflammation. Recently, it has been demonstrated that nutritional phytochemicals including polyphenols, the main active constituents of the Mediterranean diet, maintain redox balance and neuroprotection through the activation of hormetic vitagene pathway. Recent lipidomics data from our laboratory indicate mushrooms as strong nutritional neuronutrients with strongly activity against neuroinflammation in Meniere' diseaseas, a model of cochleovestibular neural degeneration, as well as in animal model of traumatic brain injury, or rotenone induced parkinson's disease. Moreover, Hidrox®, an aqueous extract of olive containing hydroxytyrosol, and Boswellia, acting as Nrf2 activators, promote resilience by enhancing the redox potential, and thus, regulate through hormetic mechanisms, cellular stress response mechanisms., Thus, modulation of cellular stress pathways, in particular vitagenes system, may be an innovative approach for therapeutic intervention in neurodegenerative disorders.

Recent advances in anti-inflammation via AMPK activation

Inflammation is a complex physiological phenomenon, which is the body's defensive response, but abnormal inflammation can have adverse effects, and many diseases are related to the inflammatory response. AMPK, as a key sensor of cellular energy status, plays a crucial role in regulating cellular energy homeostasis and glycolipid metabolism. In recent years, the anti-inflammation effect of AMPK and related signalling cascade has begun to enter everyone's field of vision - not least the impact on metabolic diseases. A great number of studies have shown that anti-inflammatory drugs work through AMPK and related pathways. Herein, this article summarises recent advances in compounds that show anti-inflammatory effects by activating AMPK and attempts to comment on them.

Natural Compounds for Preventing Age-Related Diseases and Cancers

Aging is a multifaceted process influenced by hereditary factors, lifestyle, and environmental elements. As time progresses, the human body experiences degenerative changes in major functions. The external and internal signs of aging manifest in various ways, including skin dryness, wrinkles, musculoskeletal disorders, cardiovascular diseases, diabetes, neurodegenerative disorders, and cancer. Additionally, cancer, like aging, is a complex disease that arises from the accumulation of various genetic and epigenetic alterations. Circadian clock dysregulation has recently been identified as an important risk factor for aging and cancer development. Natural compounds and herbal medicines have gained significant attention for their potential in preventing age-related diseases and inhibiting cancer progression. These compounds demonstrate antioxidant, anti-inflammatory, anti-proliferative, pro-apoptotic, anti-metastatic, and anti-angiogenic effects as well as circadian clock regulation. This review explores age-related diseases, cancers, and the potential of specific natural compounds in targeting the key features of these conditions.

Nanoplastics induced health risk: Insights into intestinal barrier homeostasis and potential remediation strategy by dietary intervention

Aged nanoplastics (aged-NPs) have unique characteristics endowed by environmental actions, such as rough surface, high oxygen content. Although studies have highlighted the potential hazards of aged-NPs, limited research has provided strategies for aged-NPs pollution remediation. The dietary intervention of quercetin is a novel insight to address the health risks of aged-NPs. This study explored the impact of aged-NPs on intestinal barrier homeostasis at the environmentally relevant dose and investigated the alleviating effects of quercetin on aged-NPs toxicity through transcriptomics and molecular biology analysis. It indicated that aged-NPs induced intestinal barrier dysfunction, which was characterized by higher permeability, increased inflammation, and loss of epithelial integrity, while quercetin restored it. Aged-NPs disrupted redox homeostasis, upregulated inflammatory genes controlled by AP-1, and led to Bax-dependent mitochondrial apoptosis. Quercetin intervention effectively mitigated inflammation and apoptosis by activating the Nrf2. Thus, quercetin decreased intestinal free radical levels, inhibiting the phosphorylation of p38 and JNK. This study unveiled the harmful effects of aged-NPs on intestinal homeostasis and the practicability of dietary intervention against aged-NPs toxicity. These findings broaden the understanding of the NPs toxicity and provide an effective dietary strategy to relieve the health risks of NPs. ENVIRONMENTAL IMPLICATIONS: Growing levels of NPs pollution have represented severe health hazards to the population. This study focuses on the toxic mechanism of aged-NPs on the intestinal barrier and the alleviating effect of quercetin dietary intervention, which considers the environmental action and relevant dose. It revealed the harmful effects of aged-NPs on intestinal inflammation with the key point of free radical generation. Furthermore, a quercetin-rich diet holds significant promise for addressing and reversing intestinal damage caused by aged-NPs by maintaining intracellular redox homeostasis. These findings provide an effective dietary strategy to remediate human health risks caused by NPs.

Exploring the potential of quercetin in Alzheimer's Disease: Pharmacodynamics, Pharmacokinetics, and Nanodelivery systems

Alzheimer's disease (AD) is a primary cause of dementia that affects millions of people worldwide and its prevalence is likely to increase largely in the coming decades. Multiple complex pathways, such as oxidative stress, tau and amyloid-beta (Aβ) pathology, and cholinergic dysfunction, are involved in the pathogenesis of Alzheimer's disease. The conventional treatments provide only symptomatic relief and not a complete cure for the disease. On the other hand, recent studies have looked into the possibility of flavonoids as an effective therapeutic strategy for treating AD. Quercetin, a well-known flavonol, has been extensively studied for AD treatment. Therefore, this review mainly focuses on the pharmacokinetics properties of quercetin and its modes of action, such as antioxidant, anti-inflammatory, anti-amyloidogenic, and neuroprotective properties, which are beneficial in treating AD. It also highlights the nano delivery systems of quercetin, including liposomes, nanostructures lipid carriers, solid lipid nanoparticles, nanoemulsions, microemulsions, self-emulsifying drug delivery systems, and nanoparticles reported for AD treatment. The remarkable potential of quercetin nanocarriers has been reflected in enhancing its bioavailability and therapeutic efficacy. Therefore, clinical studies must be conducted to explore it as a therapeutic strategy for Alzheimer's disease.

Quercetin as one of the most abundant represented biological valuable plant components with remarkable chemoprotective effects - A review

As a consequence of environmental quality changes as well as changes in our population's lifestyle, there is rapidly increasing variability and many so-called lifestyle disorders, allergies, and food intolerances (also known as non-allergic food hypersensitivity). Unhealthy eating practices, an inappropriate food composition with an excessive energy intake, a high intake of saturated fats, simple sugars, and salt, as well as an inadequate intake of fibre, vitamins, and substances with preventive effects (such as antioxidants), are some of the factors causing this detrimental phenomenon. Enhanced consumption of plant foods rich in valuable secondary metabolites such as phenolic acids and flavonoids with the benefit on human health, food research focused on these components, and production of foods with declared higher content of biologically active and prophylactic substances are some ways how to change and improve this situation. A unique class of hydroxylated phenolic compounds with an aromatic ring structure are called flavonoids. One unique subclass of flavonoids is quercetin. This phytochemical naturally takes place in fruits, vegetables, herbs, and other plants. Quercetin and its several derivates are considered to be promising substances with significant antidiabetic, antibacterial, anti-inflammatory, and antioxidant effects, which could also act preventively against cardiovascular disease, cancer, or Alzheimer's disease.

Amplification of Cardioprotective Response of Remote Ischemic Preconditioning in Rats by Quercetin: Potential Role of Activation of mTOR-dependent Autophagy and Nrf2

OBJECTIVES

Noninvasive remote ischemic preconditioning (RIPC) is a practical, acceptable, and feasible conditioning technique reported to provide cardioprotection in myocardial ischemia-reperfusion injury (MIRI). It has been well-reported that quercetin possesses antioxidant and anti-inflammatory properties. This study investigates the modification of the cardioprotective response of RIPC by quercetin.

METHODS

Adult Wistar rats were randomized into 12 groups of six animals each. MIRI was induced by subjecting the isolated hearts of Wistar rats to global ischemia for 30 min, succeeded by reperfusion of 120 min after mounting on the Langendorff PowerLab apparatus. Hind limb RIPC was applied in four alternate cycles of ischemia and reperfusion of 5 min each by tying the pressure cuff before isolation of hearts.

RESULTS

MIRI was reflected by significantly increased infarct size, LDH-1, and CK-MB, TNF-α, TBARS, and decreased GSH, catalase, and hemodynamic index, and modulated Nrf2. Pretreatment of quercetin (25 and 50 mg/kg; i.p.) significantly attenuated the MIRI-induced cardiac damage and potentiated the cardioprotective response of RIPC at the low dose. Pretreatment of ketamine (10 mg/kg; i.p.), an mTOR-dependent autophagy inhibitor, significantly abolished the cardioprotective effects of quercetin and RIPC.

CONCLUSIONS

The findings highlight the modification of the cardioprotective effect of RIPC by quercetin and that quercetin protects the heart against MIRI through multiple mechanisms, including mTOR-dependent activation of autophagy and Nrf-2 activation.

Effectiveness of Flavonoid-Rich Diet in Alleviating Symptoms of Neurodegenerative Diseases

Over the past decades, there has been a significant increase in the burden of neurological diseases, including neurodegenerative disorders, on a global scale. This is linked to a widespread demographic trend in which developed societies are aging, leading to an increased proportion of elderly individuals and, concurrently, an increase in the number of those afflicted, posing one of the main public health challenges for the coming decades. The complex pathomechanisms of neurodegenerative diseases and resulting varied symptoms, which differ depending on the disease, environment, and lifestyle of the patients, make searching for therapies for this group of disorders a formidable challenge. Currently, most neurodegenerative diseases are considered incurable. An important aspect in the fight against and prevention of neurodegenerative diseases may be broadly understood lifestyle choices, and more specifically, what we will focus on in this review, a diet. One proposal that may help in the fight against the spread of neurodegenerative diseases is a diet rich in flavonoids. Flavonoids are compounds widely found in products considered healthy, such as fruits, vegetables, and herbs. Many studies indicated not only the neuroprotective effects of these compounds but also their ability to reverse changes occurring during the progression of diseases such as Alzheimer's, Parkinson's and amyotrophic lateral sclerosis. Here, we present the main groups of flavonoids, discussing their characteristics and mechanisms of action. The most widely described mechanisms point to neuroprotective functions due to strong antioxidant and anti-inflammatory effects, accompanied with their ability to penetrate the blood-brain barrier, as well as the ability to inhibit the formation of protein aggregates. The latter feature, together with promoting removal of the aggregates is especially important in neurodegenerative diseases. We discuss a therapeutic potential of selected flavonoids in the fight against neurodegenerative diseases, based on in vitro studies, and their impact when included in the diet of animals (laboratory research) and humans (population studies). Thus, this review summarizes flavonoids' actions and impacts on neurodegenerative diseases. Therapeutic use of these compounds in the future is potentially possible but depends on overcoming key challenges such as low bioavailability, determining the therapeutic dose, and defining what a flavonoid-rich diet is and determining its potential negative effects. This review also suggests further research directions to address these challenges.

Dietary Flavonoid Quercetin Supplement Promotes Antiviral Innate Responses Against Vesicular Stomatitis Virus Infection by Reshaping the Bacteriome and Host Metabolome in Mice

SCOPE

Active ingredients in functional foods exhibit broad-spectrum antiviral activity. The objective of this study is to investigate the protective effect of quercetin derived from bee propolis, a natural product with antiviral activity and modulating effects on the gut microbiota, against vesicular stomatitis virus (VSV) infection.

METHODS AND RESULTS

Through a cellular-based study, this study demonstrates that quercetin can modulate the activity of interferon-regulating factor 3 (IRF3). In vivo, it shows that quercetin protects mice from VSV infection by enhancing interferon production and inhibiting the production of proinflammatory cytokines. The study conducts 16S rRNA-based gut microbiota and nontargets metabolomics analyses to elucidate the mechanisms underlying quercetin-mediated bidirectional communication between the gut microbiome and host metabolome during viral infection. Quercetin not only ameliorates VSV-induced dysbiosis of the intestinal flora but also alters serum metabolites related to lipid metabolism. Cross-correlations between the gut bacteriome and the serum metabolome indicate that quercetin can modulate phosphatidylcholine (16:0/0:0) and 5-acetylamino-6-formylamino-3-methyluracil to prevent VSV infection.

CONCLUSION

This study systematically elucidates the anti-VSV mechanism of quercetin through gut bacteriome and host metabolome assays, offering new insights into VSV treatment and revealing the mechanisms behind a novel disease management strategy using dietary flavonoid supplements.

Supplementation of the Combination of Quercetin and Vitamin E Alleviates the Effects of Heat Stress on the Uterine Function and Hormone Synthesis in Laying Hens

Chickens are sensitive to heat stress because their capacity to dissipate body heat is low. Hence, in chickens, excessive ambient temperature negatively influences their reproductive performance and health. Heat stress induces inflammation and oxidative stress, thereby rendering many reproductive organs dysfunctional. In this study, we evaluated the effects of the supplementation of dietary quercetin and vitamin E on the uterine function, eggshell quality via estrogen concentration, calcium metabolism, and antioxidant status of the uterus of laying hens under heat stress. The ambient temperature transformation was set at 34 ± 2 °C for 8 h/d (9:00 am-5:00 pm), which was followed by 22 °C to 28 °C for 16 h/d. Throughout the experiment, the relative humidity in the chicken's pen was at 50 to 65%. A total of 400 Tianfu breeder hens (120-days-old) were randomly divided into four dietary experimental groups, including basal diet (Control); basal diet + 0.4 g/kg quercetin; basal diet + 0.2 g/kg vitamin E; and basal diet + the combination of quercetin (0.4 g/kg) and vitamin E (0.2 g/kg). The results show that the combination of quercetin and vitamin E significantly increased the serum alkaline phosphatase levels and the antioxidant status of the uterus (p < 0.05). In addition, the combination of quercetin and vitamin E significantly increased the concentrations of serum estrogen and progesterone, as well as elevated the expression of hypothalamic gonadotropin-releasing hormone-1 and follicular cytochrome P450 family 19 subfamily A member-1 (p < 0.05). We also found that the calcium levels of the serum and uterus were significantly increased by the synergistic effects of quercetin and vitamin E (p < 0.05), and they also increased the expression of Ca2+-ATPase and the mRNA expression of calcium-binding-related genes in the uterus (p < 0.05). These results are consistent with the increased eggshell quality of the laying hens under heat stress. Further, the combination of quercetin and vitamin E significantly increased the uterine morphological characteristics, such as the height of the uterine mucosal fold and the length of the uterine mucosa villus of the heat-stressed laying hens. These results collectively improve the uterine function, serum and uterine calcium concentration, eggshell strength, and eggshell thickness (p < 0.05) in heat-stressed laying hens. Taken together, we demonstrated in the present study that supplementing the combination of dietary quercetin and vitamin E alleviated the effects of heat stress and improved calcium metabolism, hormone synthesis, and uterine function in the heat-stressed laying hens. Thus, the supplementation of the combination of quercetin and vitamin E alleviates oxidative stress in the eggshell gland of heat-stressed laying hens, thereby promoting calcium concentration in the serum and eggshell gland, etc., in laying hens. Hence, the combination of quercetin and vitamin E promotes the reproductive performance of the laying hens under heat stress and can also be used as a potent anti-stressor in laying hens.

The genus Polygonum: An updated comprehensive review of its ethnomedicinal, phytochemical, pharmacological activities, toxicology, and phytopharmaceutical formulation

Polygonum is a plant genus that includes annual and perennial species and is found at various temperatures, from northern temperate regions to tropical and subtropical areas. The genus Polygonum has been used for centuries for various disorders, including hypertension, intestinal and stomach pain, dysuria, jaundice, toothaches, skin allergies, hemorrhoids, cardiac disorders, kidney stones, hemostasis, hyperglycemia, and others. Various databases, including Google Scholar, Scifinder, ScienceDirect, PubMed, Scopus, ResearchGate, and Web of Science, were utilized to collect pertinent scientific literature data. According to bibliographic studies, the Polygonum genus possesses various compounds from different families, including phenolic acids (gallic acid, caffeic acid, quinic acid, p-coumaric acid, ferulic acid, protocatechuic acid, chlorogenic acid, and many other compounds), flavonoids (quercetin, catechin, epicatechin, quercitrin, kaempferol, myricetin, etc.), tannins, stilbenes (polydatin and resveratrol), terpenes (α-pinene, β-caryophyllene and β-caryophyllene oxide, bisabolene, β-farnesene, etc.), fatty acids (decanoic acid, lauric acid, linoleic acid, oleic acid, palmitic acid, stearic acid, dodecanoic acid), polysaccharides, and others. Various chemical and biological activities (in vitro and in vivo), such as antioxidant, antimicrobial, anticancer, antitumor, anti-inflammatory, antidiabetic, antiparasitic, hepatoprotective, neuropharmacological, gastroprotective, diuretic, antipyretic, and others, have been described in several biological studies involving this species. An updated summary of Polygonum species and their ethnomedicinal, phytochemical, toxicological, pharmacological, and phytopharmaceutical formulations is necessary. Considering the numerous potentialities of the Polygonum species and their wide-ranging use, it is extremely essential to provide knowledge by compiling the accessible literature to identify the topics of intense investigation and the main gaps to better design future studies. The objective of this review is to give readers a better understanding, greater comprehension, and in-depth knowledge of the genus Polygonum's traditional applications, phytochemistry, pharmacology, toxicological features, and galenic formulation. Several species of this genus have been detailed in this review, including those that were frequently used in traditional medicine (P. minus, P. aviculare, P. hydropiper, P. cuspidatum, and P. multiflorum) and many of the genus' therapeutic species, like P. equisetiforme, which do not get enough attention.

Optimization of Preparation Conditions for Quercetin Nanoliposomes Using Response Surface Methodology and Evaluation of Their Stability

Quercetin is a flavonol compound with excellent biological activities. However, quercetin exhibits poor stability and solubility in water, which limits its application. In this study, quercetin nanoliposomes (QUE-NL-1) were prepared using an ultrasonic thin-film dispersion method, and the preparation conditions were optimized using response surface methodology. The optimal conditions for preparing QUE-NL-1 were as follows: an evaporation temperature of 35 °C, a drug concentration of 0.20 mg/mL, and a lipid bile ratio of 4:1. The encapsulation rate of QUE-NL-1 is (63.73 ± 2.09)%, the average particle size is 134.11 nm, and the average absolute value of the zeta potential is 37.50 and PDI = 0.24. By analyzing the storage temperature, storage time, and leakage rate of QUE-NL-1 in simulated gastrointestinal fluid, it was found that quercetin exhibits good stability after embedding and can achieve sustained release in intestinal juice. In addition, the cytotoxicity of QUE-NL-1 was not significant, and the survival rate of Caco-2 cells was >90% when the concentration range of QUE-NL-1 was 0.1-0.4 mg/mL. This study provides an efficient method for preparing QUE-NL-1 with small particle sizes, good stability, and high safety, which is of great significance for expanding the application range of quercetin.

Quercetin counteracts monosodium glutamate to mitigate immunosuppression in the thymus and spleen via redox-guided cellular signaling

BACKGROUND

Chronic inflammation brought on by oxidative stress can result in several immunopathologies. Natural compounds with antioxidant characteristics, like quercetin, have shown effectiveness in reducing oxidative damage and regulating the immune response.

PURPOSE

The commonly used food additive monosodium glutamate (M) causes immunosuppression by disrupting redox equilibrium and inducing oxidative stress. The goal of this work is to examine the therapeutic potential of quercetin against immunotoxicity brought on by M, revealing the molecular route implicated in such immunopathology by targeting the thymus and spleen, to support the development of future anti-inflammatory and antioxidant therapies.

STUDY DESIGN AND METHODS

M-fed rats were employed as an immunotoxicity model and were supplemented with quercetin for four weeks. Hematological and biochemical parameters were measured; H&E staining, immunohistochemistry, flow cytometry, real-time quantitative PCR, and western blotting were performed.

RESULTS

Based on the findings, TLR4 was activated by M to cause oxidative stress-mediated inflammation, which was alleviated by the supplementation of quercetin by modulating redox homeostasis to neutralize free radicals and suppress the inflammatory response. To prevent M-induced inflammation, quercetin demonstrated anti-inflammatory functions by blocking NF-kB activation, lowering the production of pro-inflammatory cytokines, and increasing the release of anti-inflammatory cytokines. By normalizing lipid profiles and lowering the potential risk of immunological deficiency caused by M, quercetin also improves lipid metabolism. Additionally, it has shown potential for modifying insulin levels, suggesting a possible function in controlling M-induced alteration in glucose metabolism. The addition of quercetin to M enhanced the immune response by improving immunoglobulin levels and CD4/CD8 expression in the thymus and spleen. Additionally, quercetin inhibited apoptosis by controlling mitochondrial caspase-mediated cellular signaling, suggesting that it may be able to halt cell death in M-fed rats.

CONCLUSION

The results of this study first indicate that quercetin, via modulating redox-guided cellular signaling, has a promising role in reducing immune disturbances. This study illuminates the potential of quercetin as a safe, natural remedy for immunopathology caused by M, including thymic hypoplasia and/or splenomegaly, and paves the way for future anti-inflammatory and antioxidant supplements.

Transcriptional regulation of flavonol biosynthesis in plants

Flavonols are a class of flavonoids that play a crucial role in regulating plant growth and promoting stress resistance. They are also important dietary components in horticultural crops due to their benefits for human health. In past decades, research on the transcriptional regulation of flavonol biosynthesis in plants has increased rapidly. This review summarizes recent progress in flavonol-specific transcriptional regulation in plants, encompassing characterization of different categories of transcription factors (TFs) and microRNAs as well as elucidation of different transcriptional mechanisms, including direct and cascade transcriptional regulation. Direct transcriptional regulation involves TFs, such as MYB, AP2/ERF, and WRKY, which can directly target the key flavonol synthase gene or other early genes in flavonoid biosynthesis. In addition, different regulation modules in cascade transcriptional regulation involve microRNAs targeting TFs, regulation between activators, interaction between activators and repressors, and degradation of activators or repressors induced by UV-B light or plant hormones. Such sophisticated regulation of the flavonol biosynthetic pathway in response to UV-B radiation or hormones may allow plants to fine-tune flavonol homeostasis, thereby balancing plant growth and stress responses in a timely manner. Based on orchestrated regulation, molecular design strategies will be applied to breed horticultural crops with excellent health-promoting effects and high resistance.

Flavonoids: A treasure house of prospective pharmacological potentials

Flavonoids are organic compounds characterized by a range of phenolic structures, which are abundantly present in various natural sources such as fruits, vegetables, cereals, bark, roots, stems, flowers, tea, and wine. The health advantages of these natural substances are renowned, and initiatives are being taken to extract the flavonoids. Apigenin, galangin, hesperetin, kaempferol, myricetin, naringenin, and quercetin are the seven most common compounds belonging to this class. A thorough analysis of bibliographic records from reliable sources including Google Scholar, Web of Science, PubMed, ScienceDirect, MEDLINE, and others was done to learn more about the biological activities of these flavonoids. These flavonoids appear to have promising anti-diabetic, anti-inflammatory, antibacterial, antioxidant, antiviral, cytotoxic, and lipid-lowering activities, according to evidence from in vitro, in vivo, and clinical research. The review contains recent trends, therapeutical interventions, and futuristic aspects of flavonoids to treat several diseases like diabetes, inflammation, bacterial and viral infections, cancers, and cardiovascular diseases. However, this manuscript should be handy in future drug discovery. Despite these encouraging findings, a notable gap exists in clinical research, hindering a comprehensive understanding of the effects of flavonoids at both high and low concentrations on human health. Future investigations should prioritize exploring bioavailability, given the potential for high inter-individual variation. As a starting point for further study on these flavonoids, this review paper may promote identifying and creating innovative therapeutic uses.

Insights into metabolic characteristics and biological activity changes in Zangju (Citrus reticulata cv. Manau Gan) peel at different maturity stages through UPLC-MS/MS-based metabolomics

In this study, comprehensive and systematic nontargeted metabolomics analysis was performed with the metabolites of Zangju peel (Citrus reticulata cv. Manau Gan, CRZP, which has been cultivated for over 400 years in Derong County, China.) at four different mature stages. A total of 1878 metabolites were identified, among which flavonoids were the most abundant (62.04 %), and identified 62 key differential metabolites significantly affected by maturity. Based on biological activity measurements, CRZP showed better antioxidant activity, lipase inhibition ability, inhibition of adipogenic differentiation in 3TT-L1 cells and promotion of lipid metabolism, with the biological activity of CRZP at different maturity stages being associated with key differential metabolite. Thus, CRZP is natural antioxidants and possess anti-obesity potential, and industrial production needs to consider the Maturity stage of its collection.

Quercetin reshapes gut microbiota homeostasis and modulates brain metabolic profile to regulate depression-like behaviors induced by CUMS in rats

Quercetin, an abundant flavonoid compound in plants, is considered a novel antidepressant; however, its mechanisms of action are poorly understood. This study aimed to investigate the therapeutic effects of quercetin on chronic unpredictable mild stress (CUMS)-induced depression-like behaviors in rats and explore the underlying mechanisms by combining untargeted metabolomics and 16S rRNA sequencing analysis of brain tissue metabolites and gut microbiota. Gut microbiota analysis revealed that at the phylum level, quercetin reduced Firmicutes and the Firmicutes/Bacteroidetes (F/B) ratio and enhanced Cyanobacteria. At the genus level, quercetin downregulated 6 and upregulated 14 bacterial species. Metabolomics analysis revealed that quercetin regulated multiple metabolic pathways, including glycolysis/gluconeogenesis, sphingolipid metabolism, the pentose phosphate pathway, and coenzyme A biosynthesis. This modulation leads to improvements in depression-like phenotypes, anxiety-like phenotypes, and cognitive function, highlighting the therapeutic potential of quercetin in treating depression.

Modulation of hypoxia-inducible factor-1 signaling pathways in cancer angiogenesis, invasion, and metastasis by natural compounds: a comprehensive and critical review

Tumor cells employ multiple signaling mediators to escape the hypoxic condition and trigger angiogenesis and metastasis. As a critical orchestrate of tumorigenic conditions, hypoxia-inducible factor-1 (HIF-1) is responsible for stimulating several target genes and dysregulated pathways in tumor invasion and migration. Therefore, targeting HIF-1 pathway and cross-talked mediators seems to be a novel strategy in cancer prevention and treatment. In recent decades, tremendous efforts have been made to develop multi-targeted therapies to modulate several dysregulated pathways in cancer angiogenesis, invasion, and metastasis. In this line, natural compounds have shown a bright future in combating angiogenic and metastatic conditions. Among the natural secondary metabolites, we have evaluated the critical potential of phenolic compounds, terpenes/terpenoids, alkaloids, sulfur compounds, marine- and microbe-derived agents in the attenuation of HIF-1, and interconnected pathways in fighting tumor-associated angiogenesis and invasion. This is the first comprehensive review on natural constituents as potential regulators of HIF-1 and interconnected pathways against cancer angiogenesis and metastasis. This review aims to reshape the previous strategies in cancer prevention and treatment.

Quercetin, a Flavonoid with Great Pharmacological Capacity

Quercetin is a flavonoid with a low molecular weight that belongs to the human diet's phenolic phytochemicals and nonenergy constituents. Quercetin has a potent antioxidant capacity, being able to capture reactive oxygen species (ROS), reactive nitrogen species (RNS), and reactive chlorine species (ROC), which act as reducing agents by chelating transition-metal ions. Its structure has five functional hydroxyl groups, which work as electron donors and are responsible for capturing free radicals. In addition to its antioxidant capacity, different pharmacological properties of quercetin have been described, such as carcinostatic properties; antiviral, antihypertensive, and anti-inflammatory properties; the ability to protect low-density lipoprotein (LDL) oxidation, and the ability to inhibit angiogenesis; these are developed in this review.

Targeting Metabolic Diseases: The Role of Nutraceuticals in Modulating Oxidative Stress and Inflammation

The escalating prevalence of metabolic and cardiometabolic disorders, often characterized by oxidative stress and chronic inflammation, poses significant health challenges globally. As the traditional therapeutic approaches may sometimes fall short in managing these health conditions, attention is growing toward nutraceuticals worldwide; with compounds being obtained from natural sources with potential therapeutic beneficial effects being shown to potentially support and, in some cases, replace pharmacological treatments, especially for individuals who do not qualify for conventional pharmacological treatments. This review delves into the burgeoning field of nutraceutical-based pharmacological modulation as a promising strategy for attenuating oxidative stress and inflammation in metabolic and cardiometabolic disorders. Drawing from an extensive body of research, the review showcases various nutraceutical agents, such as polyphenols, omega-3 fatty acids, and antioxidants, which exhibit antioxidative and anti-inflammatory properties. All these can be classified as novel nutraceutical-based drugs that are capable of regulating pathways to mitigate oxidative-stress- and inflammation-associated metabolic diseases. By exploring the mechanisms through which nutraceuticals interact with oxidative stress pathways and immune responses, this review highlights their potential to restore redox balance and temper chronic inflammation. Additionally, the challenges and prospects of nutraceutical-based interventions are discussed, encompassing bioavailability enhancement, personalized treatment approaches, and clinical translation. Through a comprehensive analysis of the latest scientific reports, this article underscores the potential of nutraceutical-based pharmacological treatment modulation as a novel avenue to fight oxidative stress and inflammation in the complex landscape of metabolic disorders, particularly accentuating their impact on cardiovascular health.

Quercetin protects against hyperglycemia-induced retinopathy in Sprague Dawley rats by regulating the gut-retina axis and nuclear factor erythroid-2-related factor 2 pathway

Hyperglycemia-related retinopathy is a disease with a high blindness rate. Recent reports indicate that many flavonol compounds have the potential to prevent the occurrence of disease in the retina by regulating the gut-retina axis. Here, we hypothesized that quercetin could alleviate the symptoms of retinopathy. To clarify the mechanism, Sprague Dawley rats were fed a high-fat diet containing quercetin for 12 weeks and injected with streptozotocin in the ninth week. Additionally, neomycin and ampicillin were used to establish a pseudo-sterile rat model. Afterward, changes in the retina were investigated by using electroretinogram and optical coherence tomography. Blood and tissue samples were collected and biochemical components were analyzed. The extent of intestinal injury was determined via hematoxylin-eosin staining. Microbial community structure was analyzed by using 16S ribosomal RNA sequencing. Finally, the expression of genes was analyzed using real-time polymerase chain reaction. The results showed that quercetin reduced the decline in electroretinography amplitude and outer nuclear layer thickness, increased the activities of antioxidant enzymes, decreased the contents of proinflammatory factors and blood glucose, enhanced the concentration of insulin, and inhibited intestinal dysbiosis and improved gut morphology. Importantly, the underexpression of nuclear factor erythroid-2 related factor 2 in the retina was reversed by quercetin. However, trend changes were no longer significant in most of the indicators after antibiotic treatment. In summary, quercetin has therapeutic effects on retinopathy by regulating the gut-retina axis and nuclear factor erythroid-2 related factor 2 pathway, and the presence of gut microbiota helps quercetin exert its effects on the retina.

Quercetin attenuates inflammation in LPS-induced lung epithelial cells via the Nrf2 signaling pathway

BACKGROUND

Pneumonia is the leading cause of death among children under five, and kill almost two million children each year. Quercetin, a flavonoid polyphenolic compound, exerts many beneficial biological activities, including anti-inflammatory functions. Our study aimed to investigate the possibility of quercetin as a therapeutic agent for pneumonia and its role in the inflammatory response induced by lipopolysaccharide (LPS).

METHODS

LPS induced human alveolar epithelial cell A549 as a lung inflammation model in vitro. The effects of quercetin on the production of cytokines and the expression of related-proteins were detected by Enzyme-Linked ImmunoSorbent Assay and Western Blot, respectively. Cell Counting Kit-8 assay was used to detect cell viability. flow cytometry was used to measure cell apoptosis. NO levels were also analyzed through NO kit.

RESULTS

Our results found that quercetin attenuated the release of IL-1β, IL-6, PGE2, and nitrite in LPS-induced A549 cells. In addition, quercetin inhibits cell apoptosis and relieves ROS generation in LPS-induced A549 cells. Quercetin also inhibits LPS-induced NF-κB activation. They have upregulated the expression of nuclear factor erythroid 2 (Nrf2) and HO-1.

CONCLUSION

In conclusion, these results suggested that quercetin attenuates LPS-induced inflammation in A549 by activating the Nrf2 signaling pathway.

Screening of Multitarget Compounds against Acetaminophen Hepatic Toxicity Using In Silico, In Vitro, and In Vivo Approaches

Combination therapy and multitarget drugs have recently attracted much attention as promising tools to fight against many challenging diseases and, thus, represent a new research focus area. The aim of the current project was to screen multitarget compounds and to study their individual and combined effects on acetaminophen-induced liver injury. In this study, 2 of the best hepatoprotective multitargeting compounds were selected from a pool of 40 major compounds present in Curcuma longa and Cinnamomum zeylanicum by using molecular docking, ADMET profiling, and Pfizer's rule of five. The two selected compounds, quercetin and curcumin, showed a high binding affinity for the CYP2E1 enzyme, MAPK, and TLR4 receptors that contribute to liver injury. The candidates caused the decreased viability of cancer cell lines (HepG2 and Huh7) but showed no effect on a normal cell line (Vero). Examination of biochemical parameters (ALT, AST, ALP, and bilirubin) showed the hepatoprotective effect of the candidate drugs in comparison with the control group, which was confirmed by histological findings. Taken together, quercetin and curcumin not only satisfied the drug-like assessment criterion and proved to be multitargeting by preventing liver damage but also showed anticancer activities.

Content of Bioactive Compounds in Highbush Blueberry Vaccinium corymbosum L. Leaves as a Potential Raw Material for Food Technology or Pharmaceutical Industry

This study was performed to investigate the content of selected phenolic compounds, antioxidant activity and the levels of arbutin and hydroquinone in 25 varieties of highbush blueberry (Vaccinium corymbosum) leaf samples. An analysis of the bioactive components was performed using the HPLC technique and the antioxidant activity was determined via spectrophotometric methods. The content of chlorogenic acid in the analysed leaf extracts ranged from 52.76 mg/g (Spartan variety) to 32.37 mg/g (Nelson variety) and was present in the highest concentration among all the analysed phenolic acids. Particularly large levels of isoquercetin were found in the Aurora, Ivanhoe and Toro varieties (28.40 mg/g, 26.24 mg/g and 21.57 mg/g, respectively). An exceptionally high rutin content (p < 0.05) was found in the Ivanhoe variety (27.19 mg/g) as compared to the other varieties, where it ranged from 2.06 mg/g (Earliblue and Patriot varieties) to 10.55 mg/g (Bluejay variety). The Patriot variety was determined to possess the highest antioxidative activity using the FRAP method (1086.15 μmol Trolox/g d.w.) and based on its DPPH radical scavenging activity (1124.17 μmol Trolox/g d.w.). The total phenolic content (TPC) determined via spectrophotometry ranged from 48.11 mg GAE/g d.w. (Elizabeth variety) to 177.31 GAE/g d.w. (Patriot variety). The arbutin content in the leaves of all tested varieties exceeded 2%, so it can be concluded that they constitute a stable source of arbutin. Three varieties (Bonus, Chanticleer and Herbert) can be considered a potential alternative to bearberry and lingonberry leaves. The hydroquinone content in the analysed extracts was determined to be at a lower level. V. corymbosum leaves can be considered an interesting herbal material for use in traditional herbal medicinal products but not directly for food products and dietary supplements.

Research progress of plant-derived natural products in thyroid carcinoma

Thyroid carcinoma (TC) is a prevalent malignancy of the endocrine system, with a notable rise in its detection rate in recent decades. The primary therapeutic approaches for TC now encompass thyroidectomy and radioactive iodine therapy, yielding favorable prognoses for the majority of patients. TC survivors may necessitate ongoing surveillance, remedial treatment, and thyroid hormone supplementation, while also enduring the adverse consequences of thyroid hormone fluctuations, surgical complications, or side effects linked to radioactive iodine administration, and encountering enduring physical, psychosocial, and economic hardships. In vitro and in vivo studies of natural products against TC are demonstrating the potential of these natural products as alternatives to the treatment of thyroid cancer. This therapy may offer greater convenience, affordability, and acceptability than traditional therapies. In the early screening of natural products, we mainly use a combination of database prediction and literature search. The pharmacological effects on TC of selected natural products (quercetin, genistein, apigenin, luteolin, chrysin, myricetin, resveratrol, curcumin and nobiletin), which hold promise for therapeutic applications in TC, are reviewed in detail in this article through most of the cell-level evidence, animal-level evidence, and a small amount of human-level evidence. In addition, this article explores possible issues, such as bioavailability, drug safety.