Quercetin Research Articles

Isoquercitrin Loaded PEGylated Long Circulating Liposomes Improve Bone Mass and Reduce Oxidative Stress After Osteoporosis.

Osteoporosis has increasingly become a major public health concern because of its associated heightened risk of bone fragility and fractures. In order to avoid the adverse risk of hormone therapy, scientists have considered isoquercitrin (IQ) as a natural phytoestrogen to potentially prevent osteoporosis. However, IQ has poor solubility and bioavailability which culminates in rapid elimination of phytoestrogen. Herein, this study sought to solve limited applications of IQ by preparing IQ-loaded PEGylated long circulating liposomes (IQ-Lips) via thin-film hydration method. After appropriate characterization using zeta-potential, polydispersed index (PDI), particle size and entrapment efficiency (EE), IQ-Lips were applied to ovariectomized rat models to evaluate their effect on osteoporosis. The results showed that the prepared IQ-Lips exhibited smaller sized nanoparticles (125.35 ± 4.50nm), excellent PDI (0.244 ± 0.001) and zeta-potential (-28.64 ± 0.71 mV) with stable property and higher EE (92.10 ± 0.32%). Importantly, administration of IQ-Lips through oral route increased aqueous solvability, bioavailability and circulation time of IQ. Moreover, the IQ-Lips could increase bone microstructural densities and bone mass, as well as reduce oxidative stress in ovariectomized rat models. Altogether, the IQ-Lips may serve as a novel avenue to potentially prolong the circulation of IQ in the body and improve the bioavailability of IQ for treatment of osteoporosis.

The effect of quercetin and citrulline on cycling time trial performance.

There is growing interest in the use of nutrition and dietary supplements to optimize training and time-trial (TT) performance in cyclists. Separately, quercetin (QCT) and citrulline (CIT) have been used as ergogenic aids to improve oxygen (VO2) kinetics, perceived effort, and cycling TT performance. However, whether the combination of QCT and CIT can provide additive benefits and further enhance cycling performance production is currently unknown. We examined 28-days of QCT + CIT supplementation on TT performance and several performance measures (i.e. mean power, VO2, respiratory exchange ratio (RER), and rate of perceived exertion (RPE)). Forty-eight highly trained cyclists were assigned to one of four supplementation groups: (1) QCT + CIT (QCT: 500 mg, CIT: 3000 g), (2) QCT (500 mg), (3) CIT (3000 mg), or (4) placebo (3500 mg of a zero-calorie flavored crystal light package). Supplements were consumed two times per day for 28 consecutive days. Participants performed a 20-km cycling time-trial race, pre- and post-supplementation to determine the impact of the combined effects of QCT + CIT. There were no potential benefits of QCT +CIT supplementation on TT performance and several performance measures. However, there was an improvement in VO2 from pre-to-post-supplementation in QCT (p = 0.05) and CIT (p = 0.04) groups, but not in the QCT+CIT and PL groups. QCT + CIT does not seem beneficial for 20-km TT performance; further exploration with a focus on an increase in cycling duration or QCT+CIT combined with additional polyphenols may amplify any perceived bioactive or metabolic effects on cycling performance. The efficacy of QCT + CIT supplementation to improve cycling performance remains ambiguous.

Evaluation of Quercetin's Bioenhancing Effect on Oral Pharmacokinetics of Rosuvastatin in Wistar Rats Using RP-HPLC Method.

The absolute oral bioavailability of rosuvastatin (RST), a secondgeneration statin, is low i.e. 20% and only 10% is recovered as metabolite N-desmethy l rosuvistatin. Since it is a hydrophilic statin, RST relies on the organic anion transporting polypeptide- 1B1 (OATP-1B1), as the key mechanism for active transport into hepatocytes. Quercetin (QUE) being a bio enhancer and inhibitor of OATP1B1 can augment the bioavailability and pharmacokinetics of RST. The present study includes the development of a simple and validated bioanalytical Reverse Phase High-Performance Liquid Chromatography (RP-HPLC) method for the estimation of RST and to study the effect of co-administration of QUE as a bio enhancer on its bioavailability. An analytical column of Kromasil 100, C18 (250 mm × 4.6 mm, 5 μm), was used for chromatographic separationand acetonitrile (ACN): acetic acid buffer pH 3.0 adjusted with glacial acetic acid (55:45 Vol. %) as mobile phase with flow rate 1.0 ml/min monitored at 242 nm. The ACN: methanol (50:50 Vol. %) was employed as the final solvent for extraction. The developed method has been successfully applied in a study on the pharmacokinetics of the drug RST in rats after co-administration of QUE, which was carried out using non-compartmental analysis in order to estimate the blood concentration of the drug. The pharmacokinetics of RST was found to be altered significantly (highest concentration of RST in the blood (Cmax) = 67.3 ng/ml to 122.2 ng/ml) (p < 0.001), area under curve (AUC)0-t (p < 0.0001) and AUC0-inf (p = 0.0005) when co-administered with QUE at 120 min (tmax). The results are in accordance with the fact that QUE increases plasma levels in rats through herb-drug interactions.

Preparation, characterization, stability, and antioxidant of quercetin-loaded hyaluronic acid complexes via pH-induced co-assembly

The purpose of this study was to investigate the feasibility of constructing an oral delivery system for quercetin (QUT) using hyaluronic acid (HA) as the wall material. The findings revealed that when the mass ratio of QUT to HA was 1:10, the prepared QUT-HA complexes exhibited excellent stability (particle size of 802 nm, zeta potential of -36 mV) and QUT loading capacity (encapsulation efficiency of 79.77%, loading capacity of 89.65 mg/g). The characterization of QUT-HA complex confirmed the formation of hydrogen bond between QUT and HA, resulting in a homogeneously dispersed coral-like complex and leading to the transformation of QUT's crystal structure into an amorphous state. Environmental stability analysis demonstrated that the QUT-HA complex maintains good stability within an ionic concentration range of 0-500 mM, a pH range of 3-8, and at temperatures of 50-90°C. In vitro simulations of gastrointestinal digestion indicated that the QUT-HA complex aggregates during simulated gastric fluid digestion and dissociates following simulated intestinal fluid digestion, effectively enhancing the bioaccessibility of QUT. Antioxidant assays showed that the scavenging ability of QUT against DPPH and ABTS radicals was significantly improved by complex loading. Therefore, the QUT-HA complex developed in this study possesses a high QUT loading capacity, excellent processing and digestive stability, and can effectively enhance the bioaccessibility and antioxidant activity of QUT, making it a promising candidate for use as an oral nutritional supplement in the field of functional foods.

Research on the role and mechanism of Aloe vera (L.) Burm.f. in the treatment of burn: Based on network pharmacology analysis and experimental verification

Burn is a suddenly occurring injury. The healing process of burn is complex. Aloe vera (L.) Burm.f. (Av) is widely used as Chinese folk medicine for the treatment of burn. While effective pharmacological components, role and mechanism of Av in the treatment of burn remain to be fully elucidated. Arachidonic Acid (AA) and Quercetin (QUE) are identified as active components of Av for the treatment of burn by network pharmacology analysis and experimental verification. Animal experiments’ results showed that AA and QUE could shorten the burn wound healing time. The expression of inflammatory factor TNF-α, MyD88 and P-NF-κB p65 were down-regulated and the ER (ESR1), SRC were up-regulated in AA treated NIH 3T3 cells. The expression of MyD88 was downregulated in QUE treated NIH 3T3 cells. The Av promotes burn healing may be via the anti-inflammatory effect and regulation on NF-κB signal pathway or estrogen signal pathway by its active components AA and QUE. This research may construct a bridge between Av and burn wounds, and skin therapy agent exploration.

Isoquercitrin promotes hair growth through induction of autophagy and angiogenesis by targeting AMPK and IGF-1R

BackgroundHair follicles play a crucial role in hair growth, wound healing, thermoregulation, and sebum production. Hair loss affects millions of people worldwide, yet therapeutic options for managing hair loss and pattern baldness are limited. Isoquercitrin (IQ), a natural small molecule from drinkable Chinese tea, is famous for anti-aging properties. PurposeThis study aimed to explore the potential of IQ in treating and preventing hair loss, along with its underlying mechanisms. MethodsThe adult male and female, as well as middle-aged female sprague dawley (SD) rats were used to conduct hair growth experiments in vivo. Signaling pathways and target protein identification were analyzed through western blotting, drug affinity responsive target stability (DARTS), cellular thermal shift assay (CETSA) and surface plasmon resonance (SPR) analyses. Further, the targets were confirmed through in vivo inhibition experiments. ResultsIQ is reported here to stimulate anagen phase initiation and hair regrowth by directly interacting with adenosine 5′-monophosphate-activated protein kinase (AMPK) and insulin-like growth factor 1 receptor (IGF-1R). This process involves the AMPK/mammalian target of rapamycin (mTOR)/ unc-51-like autophagy-activating kinase 1 (ULK1) signalling pathway to trigger autophagy and the IGF-1R/phosphatidylinositol 3-kinase (PI3 K)/protein Kinase B (AKT), vascular endothelial growth factor (VEGF)/ vascular endothelial growth factor receptor (VEGFR)/ angiotensin (ANG) pathways to promote angiogenesis in female rats. Furthermore, the hair regrowth efficacy of IQ in adult male rats and middle-aged female rats was verified and shown. Similarly, our findings indicate that IQ promotes hair regrowth in middle-aged rats through autophagy and angiogenesis, akin to its effects in adult rats. ConclusionAMPK and IGF-1R proteins are identified as the target proteins of IQ and the AMPK/mTOR/ULK1, IGF-1R/PI3K/AKT and VEGF/VEGFR/ANG signalling pathways take important roles in hair growth effect of IQ. Thus, these signaling pathways are crucial for developing future treatments and clinical strategies for hair regeneration.

Modification of adipogenesis and oxidative stress by quercetin: positive or negative impact on adipose tissue metabolism of obese diabetic Zucker rats?

Reactive oxygen species (ROS) play a key role in the regulation of adipogenesis. The aim of our study was to investigate the effect of quercetin (QCT) supplement on obese adipose tissue metabolism of 30-week-old diabetic Zucker rats (ZDF), not well examined yet. QCT was administered orally at dose of 20mg/kg body weight/day for 6 weeks. Adipocytes from subcutaneous adipose tissue (ScWAT) were isolated and their size was evaluated by light microscopy. Gene expression of adipogenic markers in subcutaneous and visceral adipose tissue was determined by real-time PCR and expression of proteins involved in lipid and glucose metabolism was determined in ScWAT by immunoblotting. Obese ZDF rats suffered from diabetes, hyperinsulinemia and had higher index HOMA-IR (Homeostatic Model Assessment for Insulin Resistance). Treatment with QCT had no significant impact on these metabolic disorders in genetic model of obesity and type 2 diabetes used in our study. Nevertheless, QCT reduced expression of inflammatory cytokine tumour necrosis factor alpha in ScWAT and also visceral adipose tissue and up-regulated expression of anti-inflammatory adiponectin in ScWAT. A shift in redox equilibrium was detected via inhibition of pro-oxidant genes by QCT. Furthermore, QCT reduced adipocyte size in ScWAT, down-regulated expression of fatty acid synthase and adipogenic markers, and moreover stimulated expression of proteolytic enzymes. These changes likely resulted in reduced fat deposition in ScWAT, which was reflected in the elevated circulated levels of free fatty acids in QCT-treated obese ZDF rats compared with obese untreated controls. This increase could, at least in part, explain why we did not observe an improvement in systemic metabolic health by QCT in our model. In conclusion, our study suggests that preventive treatment with QCT might be more effective than its administration in the stage of fully developed diabetes, and further research in this area is needed.

Unveiling the Potential Prebiotic Effects of Edible Mushroom Pleurotus djamor During In Vitro Colonic Fermentation.

The ability of edible mushrooms to modulate the intestinal microbiota is a topic of interest. This study shows that digested Pleurotus djamor powder (MUS) exhibits prebiotic effects during an in vitro colonic fermentation. Phenolic compounds, including epicatechin (3.03 ± 1.54 mg/L), gallic acid (2.71 ± 1.54 mg/L), and quercetin 3-glucoside (2.40 ± 1.54 mg/L), were found in P. djamor. MUS significantly increased the relative abundance of Lactobacillus spp./Enterococcus spp. (1.12% - 4.83%), Bifidobacterium spp. (0.59% - 1.85%), Ruminococcus albus/R. flavefaciens (0.37% - 1.88%), and reduced Clostridium histolyticum (2.89% - 1.22%) during 48 of colonic fermentation. MUS enhanced lactic acid and short-chain fatty acid production and decreased pH levels. The 1H NMR analysis revealed the presence of essential amino acids, branched-chain amino acids, and other compounds that benefit human health. The results indicate the prebiotic effects of P. djamor on human intestinal microbiota.

Co-Administration of a Plantain-Based Diet and Quercetin Modulates Atrazine-Induced Testicular Dysfunction in Rats via Testicular Steroidogenesis and Redox-Inflammatory Processes.

Plantain has been reported to enhance testicular function indices, however, the mechanism remains unknown. The present study investigated the action mechanisms of a plantain-based diet in the treatment of rat testicular dysfunction caused by exposure to atrazine (ATZ). The rats were grouped into 10 groups (5 rats each); control group, 50% plantain-based diet (50% PBD), 25% PBD, 12.5% PBD, quercetin (QUE), ATZ only, 50% PBD + ATZ, 25% PBD + ATZ, 12.5% PBD + ATZ, and QUE + ATZ for 21 days. Results revealed that ATZ treatments in rats lowered gonadal hormone levels and the semen quality (sperm concentration, motility, count, and viability), damaged testicular morphology and functions, and impaired redox-inflammatory balance as well as cholinergic and purinergic activities. However, treatment with PBD and QUE ameliorated the testicular toxicity induced by ATZ, although the treatment did not improve the rat semen quality. In addition, the ATZ + QUE and QUE groups showed mild to moderate atrophic degenerative changes, with reduced spermatogenic activity. Together, the results are evidence that 21 days of exposure to ATZ impaired testicular function. However, co-administration of atrazine and PBD improves rat gonadal hormones, redox state, inflammatory indices, cholinergic, and purinergic activities, as well as histoarchitecture of the testes.

Comparative Analysis of Bare and Quercetin-Loaded Nonionic Block Copolymer Micelles in an Artificial Gastrointestinal Medium.

Block copolymer micelles have been increasingly used for the solubilization and delivery of hydrophobic drugs. There exists a possibility of dissociation of micelles and formation of other association structures in contact with the gastrointestinal fluid. In this study, we demonstrated the effect of the fed-state intestinal fluid (FeSSIF) upon characteristics of bare and quercetin (QCT)-loaded pluronic 123 (P123) micelles. Characterizations were performed using dynamic light scattering (DLS), 1H NMR, heteronuclear single-quantum coherence (HSQC), two-dimensional 1H-1H nuclear Overhauser effect spectroscopy (2D-NOESY), and diffusion-ordered spectroscopy (DOSY). In the case of bare micelles, we found copolymer-bile salt mixed aggregates without any noticeable change in size. DOSY data revealed that lecithin formed a separate aggregate in the FeSSIF. Complete micellar solubilization of QCT could be verified by the disappearance of its proton signals. At higher dose levels, the diffusion coefficient of micelles increased in the FeSSIF. We speculate that QCT-induced hydrophobicity and availability of FeSSIF components would have driven the formation of small-sized mixed assemblies. On the contrary, the diffusion coefficient of micelles decreased with an increase in the QCT load in the medium devoid of FeSSIF components. We deduce that lack of lecithin and bile salts precluded the formation of mixed assemblies in this case, and therefore, micelles turned heavier at higher QCT loads. Such insights on self-assembled formulations can be valuable in improving their biological performance.

Optimization and characterization of electrospun bilayered PVA/collagen nanofibers loaded with quercetin for tissue engineering applications

Bilayered electrospun membranes for skin tissue engineering and wound dressings were developed using Poly vinyl alcohol (PVA), collagen (COLL), chitosan (CH), and a tamarind seed polysaccharide (TSP) are crosslinked with quercetin (QU). To maintain a sustained release of drug from the membrane we have developed a novel crosslinked two layered stable PVA fibrous mat, top layer composed of PVA/CH/TSP and quercetin and the bottom layer is composed of PVA/CH/COLL. Developed bilayered scaffolds were characterized using Field Emission Scanning Electron Microscope (FE-SEM) and their surface morphologies exhibited random fibrous orientation with porous morphology. Cross sectional images showed the junction of the bilayered scaffold with different fiber morphology between the layers. The results revealed fibrous bilayer separation confirming the bilayered scaffold with uniform porosity which is beneficial for tissue engineering application, moreover the PVA fibrous mats are stable after crosslinking it with quercetin, more than 24 h. Invitro biological studies results also showed desirable cell viability on fibroblast cells with increased proliferation and adhesion on the bilayer material making it potential for targeted tissue engineering application.

Inhibitory activity of nanoencapsulated quercetin against sodium arsenite-induced sub-acute liver toxicity in rats

Arsenic, a metalloid toxicant, is associated with a major global health problem as oxidative stress, a prime cause of tissue toxicity. The subject of our investigation was to assess the therapeutic efficiency of nanoencapsulated quercetin (QC) in combating sodium arsenite (NaAsO2)-inducted sub-acute hepatocellular toxicity in rat model. The rats of the hepatic damage group were injected subcutaneously (s.c.) four dosages of NaAsO2 (92.36 µM/kg b.wt.) twice a week. The rats of the polylactide nanoencapsulated QC group were injected intravenously (i.v.) four doses of nanoencapsulated QC (8.97 µmol/kg b.wt.) twice a week 2 h after the treatment (s.c.) with 92.36 µM /kg b. wt. NaAsO2 twice a week for four doses. The rats of the empty nanocasule or free QC treated group were injected i.v. four doses empty nanocapsule or free QC twice a week 2 h after the treatment (s.c.) with same doses of NaAsO2 twice a week for four doses. Arsenic deposition (580±20 µg/g protein) observed in liver tissue of rats treated with arsenite (92.36 µM/kg b.wt.), was found to reduce (120±9 µg/g protein) by the treatment of nanoencapsulated QC in rats significantly (p&lt;0.001). The levels of antioxidant enzymes and GSSG/GSH ratio enhanced (p&lt;0.001/0.1/0.01) by the treatment of NaAsO2 were reduced by the post treatment of nanoencapsulated QC significantly (p&lt;0.001/0.01). The levels of ROS, lipohydroperoxide or membrane microviscosity increased or decreased (p&lt;0.001) by the treatment of NaAsO2 were monitored to reduce or enhance significantly (p&lt;0.001) by the treatment of nanoencapsulated QC in rat liver respectively. The blood serum biochemical levels enhanced (p&lt;0.001) by the treatment of NaAsO2 were found to reduce significantly (p&lt;0.001) by the treatment of nanoencapsulated QC in rats. The TGFβ1 and MMP-13 in the rat plasma augmented (p&lt;0.001) by the treatment of NaAsO2-exposure were found to decline (p&lt;0.001) significantly by the treatment of nanoencapsulated QC in rats. The rats in the other groups such as empty nanocapsule or free QC treated showed no or less inhibitory efficiency against NaAsO2-treatment compared to nanoencapsulated QC treated group. Application of nanoencapsulated QC may be a potent formulation to get higher inhibitory therapeutic efficiency against NaAsO2-induced sub-acute hepatocellular toxicity.

Inflammatory mediators-induced DNA damage in liver and brain injury: Therapeutic approach of 5-Methoy-N-acetyltryptamine

The pathophysiology of hepatic and cerebral damage includes various molecular and signalling pathways. Assessment of inflammation-induced DNA damage is one of the principal issues for investigating organ distortion and mutation. The current study was premeditated to discover the prophylactic role of 5-Methoy-N-acetyltryptamine (5-MNAT) and/or Quercetin (QR) versus sodium nitrite (NaNO2) induced liver and brain injury in a rat model, as well as to clarify the different cross-linked inflammatory pathways and neurotransmitters. Pre-treatment with QR and 5-MNAT was followed with NaNO2 administration in a dose of (75 mg/kg BW). NaNO2-intoxication significantly caused alleviation in inflammatory biomarkers including C-reactive protein (CRP) and interleukin-6 (IL-6). The above-mentioned antioxidants noticeably amended the altered inflammatory biomarkers signalling pathways and liver function biomarkers including alanine aminotransferase (ALT) and lactate dehydrogenase (LDH). Furthermore, they modulated brain neurotransmitters including, GABA and serotonin in brain tissue. Likewise, the COMET assay revealed that these antioxidants successfully modified NaNO2-induced liver and brain DNA damage. In conclusion, treatment with both QR and 5-MNAT revealed the most effective therapeutic index in improving NaNO2-induced liver and brain injury, confirming the effectiveness of this combination as a powerful treatment for brain hypoxia. Nevertheless, this was confirmed with histopathological investigation.

Gamma-irradiated hydroxyapatite based electrochemical sensor for simultaneous detection of rutin and quercetin flavonoids

Semi-synthetic flavonoids, such as rutin and its aglycone, quercetin, are of considerable interest in nutraceuticals, pharmaceuticals, and traditional medicine due to their health benefits. Here, we report the synthesis of hydroxyapatite (HA), its subsequent modification through gamma irradiation, and fabrication of an electrochemical sensor for the selective and simultaneous determination of quercetin (QR) and rutin (RT). Under optimized conditions, the GI-HA modified glassy carbon electrode (GCE) showcased sharp peaks at 0.29 V and 0.39 V corresponding to the oxidation potentials of QR and RT respectively in phosphate-buffered saline at pH 6. The fabricated sensor exhibited the lowest detection limits of 0.02 µM for QR and 0.018 µM for RT over a wide linear concentration range from 0.02 to 800 µM for both compounds. Furthermore, the sensor displayed excellent storage stability, reproducibility, and repeatability, with relative standard deviations of less than 5 %. The practical applicability of the sensor was demonstrated by measuring QR and RT in amaranthus viridis (a perennial medicinal herb), red onions, and pharmaceutical samples. Interestingly, a transition from RT to QR has been observed in the amaranthus viridis during its cooking in water at temperatures ranging from 80 to 100 ℃. Additionally, the sensor demonstrated a notable increase in QR levels in red onions exposed to sunlight over the course of a week. Thus, the 100 kGy GI-HA modified GCE has the potential to monitor QR and RT in food and pharmaceutical samples, either independently or simultaneously.

Quercetin and its potential therapeutic effects on aluminum phosphide-induced cardiotoxicity in rats: Role of NOX4, FOXO1, ERK1/2, and NF-κB

Acute Aluminum phosphide (AlP) poisoning poses a serious global issue, yet the exact mechanisms behind AlP-induced cardiotoxicity are still not well understood. Moreover, there is no specific antidote available for AlP toxicity. Nevertheless, Quercetin (QE) has emerged as a promising therapeutic candidate in various contexts. Accordingly, our study aimed to evaluate the QE potential therapeutic effects against AlP-induced cardiotoxicity and the mechanisms underlying such effects. Rats were assigned into four groups: Group I (control group), Group II (vehicle (corn oil) group), Group III (AlP group) received a single dose of AlP (10 mg/kg body weight) dissolved in corn oil by oral gavage, and Group IV (AlP + QE group) received a single dose of QE (400 mg/kg body weight) dissolved in saline, one hour after AlP administration. AlP-induced cardiotoxicity was evidenced by the increase in cardiac troponin I (cTnI) as well as the hemodynamic, ECG, and histopathological abnormalities. The AlP group denoted a decrease of the antioxidant enzymes; catalase and SOD and an increase of the lipid peroxidation marker; MDA. This was associated with a notable increase in inflammatory cytokines (TNFα, IL-6, and IL1β), in addition to a significant upregulation of the expression of NOX4, FOXO1, ERK1/2, and NF-κB. Moreover, Caspase3, and BAX showed strong immunopositive expression, while Bcl-2 showed mild immunoexpression. On the other hand, treatment with QE showed an improvement in the cardiotoxic effects of AlP, as indicated by significant enhancements in biomarkers, functional assessments, and histopathological findings. These results suggest that QE may be a promising candidate for treating AlP-induced cardiotoxicity, attributed to its antioxidant, anti-inflammatory, and anti-apoptotic properties, particularly emphasizing the roles of NOX4, FOXO1, ERK1/2, and NF-κB.

Antioxidant hydrogel from poly(aspartic acid) and carboxymethylcellulose with quercetin loading as burn wound dressing

Susceptibility to infection and excessive accumulation of reactive oxygen species (ROS) are the greatest obstacles for burn wound healing. In this research, the 5-aminosalicylic acid (ASA) grafted poly(aspartic hydrazide) (PASH) was synthesized by successive ploysuccinimide (PSI) ring opening reaction and reacted with oxidized carboxymethyl cellulose (DCMC) to fabricate biodegradable hydrogel through Schiff-base cross-linking. Moreover, the hydrogel was loaded with quercetin (QT) to enhance its anti-inflammatory performance. The ASA moiety endowed the hydrogel with the free radical scavenging ability and mussel inspired tissue adhesion to maintain the healing bioenvironment of the wound. The loading of QT gave the hydrogel more phenolic hydroxy group and further enhanced the antioxidant capacity of the hydrogel. The in vitro experiment revealed the grafted ASA moiety and the loaded QT greatly enhanced the ROS elimination property and antibacterial property. Moreover, the QT loaded hydrogel accelerated the burn wound repairing rate in the in vivo mice model. Based on above result, the PASH/DCMC could act as a new platform for QT loading to promote the burn wound repairing.

Quercetin: A Promising Candidate for the Management of Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD).

Metabolic dysfunction-associated steatotic liver disease (MASLD) represents a chronic liver disease. The development of MASLD is influenced by a multitude of diseases associated with modern lifestyles, including but not limited to diabetes mellitus, hypertension, hyperlipidaemia and obesity. These conditions are often consequences of the adoption of unhealthy habits, namely a sedentary lifestyle, a lack of physical activity, poor dietary choices and excessive alcohol consumption. The treatment of MASLD is primarily based on modifying the patient's lifestyle and pharmacological intervention. Despite the absence of FDA-approved pharmacological agents for the treatment of MASLD, several potential therapeutic modalities have demonstrated efficacy in reversing the histopathological features of the disease. Among the botanical ingredients belonging to the flavonoid group is quercetin (QE). QE has been demonstrated to possess a number of beneficial physiological effects, including anti-inflammatory, anticancer and antifungal properties. Additionally, it functions as a natural antioxidant. Preclinical evidence indicates that QE may play a beneficial role in reducing liver damage and improving metabolic health. Early human studies also suggest that QE may be an effective treatment for MASLD due to its antioxidant, anti-inflammatory, and lipid-regulating properties. This review aims to summarize the available information on the therapeutic effects of QE in MASLD.

Quercetin Alleviates Scleral Remodeling Through Inhibiting the PERK-EIF2α Axis in Experiment Myopia.

This study aims to investigate the effect of quercetin (QUE) on scleral remodeling by inhibiting the PERK-EIF2α signaling pathway and to evaluate its potential role in slowing myopia. Lens-induced myopia (LIM) guinea pigs were obtained and treated with QUE. After 4 and 6 weeks of treatments, ocular biological measurements were conducted. Hematoxylin and eosin (H&E) staining was used to observe the changes in scleral morphology and thickness, and Masson staining was used to examine scleral collagen fiber arrangement. Quantitative PCR (qPCR) and Western bolt were utilized to detect the mRNA and protein expression of PERK, EIF2α, MMP-2, TIMP-2, and collagen I in the scleral tissues. Calcium ion flow in each group was measured using noninvasive micro-test technology, and reactive oxygen species levels were detected by flow cytometry. Compared with the LIM group, the ocular measurements showed that the refractive errors and axial length of the eyes were significantly reduced in the LIM+QUE group (P < 0.01). H&E and Masson staining showed that sclera in the LIM+QUE group was thickened, collagen was dense, and the fiber gap was reduced. In the LIM+QUE group, the expression levels of PERK, EIF2α, and MMP-2 were decreased, whereas the expression levels of TIMP-2 and collagen I were increased. Calcium release and reactive oxygen species (ROS) in the LIM+QUE group were decreased. Quercetin ameliorates scleral remodeling in myopic guinea pigs by inhibiting the PERK-EIF2α signaling pathway, thereby alleviating the progression of myopia. These findings provide new experimental evidence for the potential application of quercetin in myopia prevention and treatment.

Quercetin Boosts Pulsatile Gonadotropin-Releasing Hormone Release to Improve Luteal Function via Inhibiting NF-κB/NLRP3-Mediated Neuron Pyroptosis.

Luteal phase deficiency (LPD) is the main cause of infertility without an effective cure. Quercetin (QUE) is a bioactive flavonoid with antioxidant properties, while its role in treating LPD remains unclear. This study aims to investigate the therapeutic effects of QUE on infertility and menstrual disorders induced by LPD, thus further exploring the underlying mechanism. Mifepristone-induced rats are used to explore the protective effects of QUE against LPD. QUE stimulates the spontaneous secretion of progesterone to improve luteal function and endometrial receptivity in LPD rats by activating the kisspeptin/GPR54 system to facilitate the gonadotropin-releasing hormone (GnRH) pulsatility. Bioinformatics analysis reveals that the core mechanism of QUE in treating LPD is to attenuate the GnRH neuron pyroptosis by inhibiting the NF-κB pathway, which is further verified in LPD rats and lipopolysaccharide (LPS)-treated GT1-7, as QUE significantly reduces the expression of key factors concerning NF-κB pathway and NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome. This study first proposes that neuron pyroptosis-induced GnRH pulsatility disruption accounts for the pathogenesis of LPD, and QUE facilitates the pulse secretion of GnRH to boost the spontaneous progesterone secretion by inhibiting NF-κB/NLRP3-mediated neuron pyroptosis, which provides a new therapeutic target and strategy for LPD.

Quercetin protects the liver of broiler chicken against oxidative stress and apoptosis induced by ochratoxin A

Ochratoxin A (OTA) is a mycotoxin that causes major health concerns in human and animals. Quercetin (QUE) is a flavonoid that possesses antioxidant, anti-inflammatory and anti-apoptotic properties. This report aims to investigate the ameliorative effects of QUE against OTA-induced hepatotoxicity in broiler chicken. Forty broiler chicks were equally allocated into 4 groups: Group I (control), Group II (OTA), Group III (QUE) and Group IV (OTA + QUE). OTA (0.5 mg/kg) and QUE (0.5 g/kg) were incorporated into the chicken feed for 42 days. The results presented a significant decrease in body weight and elevation in feed conversion ratio, and a significant elevation of the activities of serum alanine aminotransferase and aspartate aminotransferase enzymes in the OTA birds. Additionally, there was a significant decrease in catalase activity and reduced glutathione content and a significant elevation in malondialdehyde level in the liver of OTA-exposed birds. Various hepatocellular lesions were also noticed in the OTA-exposed birds. OTA exposure up-regulated the phosphatase and tensin homologue (PTEN) and the pro-apoptotic genes and down-regulated the anti-apoptotic genes in the liver. The addition of QUE ameliorated most of the hepatotoxic effects of OTA.