Protective mechanism of quercetin in alleviating sepsis-related acute respiratory distress syndrome based on network pharmacology and in vitro experiments

BACKGROUND:Sepsis-related acute respiratory distress syndrome(ARDS)has a high mortality rate,and no effective treatment is available currently.Quercetin is a natural plant product with many pharmacological activities,such as antioxidative,anti-apoptotic,and anti-inflammatory effects.This study aimed to elucidate the protective mechanism of quercetin against sepsis-related ARDS.METHODS:In this study,network pharmacology and in vitro experiments were used to investigate the underlying mechanisms of quercetin against sepsis-related ARDS.Core targets and signaling pathways of quercetin against sepsis-related ARDS were screened and were verified by in vitro experiments.RESULTS:A total of 4,230 targets of quercetin,360 disease targets of sepsis-related ARDS,and 211 intersection targets were obtained via database screening.Among the 211 intersection targets,interleukin-6(IL-6),tumor necrosis factor(TNF),albumin(ALB),AKT serine/threonine kinase 1(AKT1),and interleukin-1β(IL-1β)were identified as the core targets.A Gene Ontology(GO)enrichment analysis revealed 894 genes involved in the inflammatory response,apoptosis regulation,and response to hypoxia.Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analysis identified 106 pathways.After eliminating and generalizing,the hypoxia-inducible factor-1(HIF-1),TNF,nuclear factor-κB(NF-κB),and nucleotide-binding and oligomerization domain(NOD)-like receptor signaling pathways were identified.Molecular docking revealed that quercetin had good binding activity with the core targets.Moreover,quercetin blocked the HIF-1,TNF,NF-κB,and NODlike receptor signaling pathways in lipopolysaccharide(LPS)-induced murine alveolar macrophage(MH-S)cells.It also suppressed the inflammatory response,oxidative reactions,and cell apoptosis.CONCLUSION:Quercetin ameliorates sepsis-related ARDS by binding to its core targets and blocking the HIF-1,TNF,NF-κB,and NOD-like receptor signaling pathways to reduce inflammation,cell apoptosis,and oxidative stress.

Nitrogen application regulates antioxidant capacity and flavonoid metabolism,especially quercetin,in grape seedlings under salt stress

Salt stress is a typical abiotic stress in plants that causes slow growth,stunting,and reduced yield and fruit quality.Fertilization is necessary to ensure proper crop growth.However,the effect of fertilization on salt tolerance in grapevine is unclear.In this study,we investigated the effect of nitrogen fertilizer(0.01 and 0.1 mol L^(-1)NH_(4)NO_(3))application on the salt(200 mmol L^(-1)NaCl)tolerance of grapevine based on physiological indices,and transcriptomic and metabolomic analyses.The results revealed that 0.01 mol L^(-1)NH_(4)NO_(3) supplementation significantly reduced the accumulation of superoxide anion(O_(2)^(-)·),enhanced the activities of superoxide dismutase(SOD)and peroxidase(POD),and improved the levels of ascorbic acid(AsA)and glutathione(GSH)in grape leaves compared to salt treatment alone.Specifically,joint transcriptome and metabolome analyses showed that the differentially expressed genes(DEGs)and differentially accumulated metabolites(DAMs)were significantly enriched in the flavonoid biosynthesis pathway(ko00941)and the flavone and flavonol biosynthesis pathway(ko00944).In particular,the relative content of quercetin(C00389)was markedly regulated by salt and nitrogen.Further analysis revealed that exogenous foliar application of quercetin improved the SOD and POD activities,increased the AsA and GSH contents,and reduced the H_(2)O_(2) and O_(2)^(-)·contents.Meanwhile,10 hub DEGs,which had high Pearson correlations(R^(2)>0.9)with quercetin,were repressed by nitrogen.In conclusion,all the results indicated that moderate nitrogen and quercetin application under salt stress enhanced the antioxidant system defense response,thus providing a new perspective for improving salt tolerance in grapes.

Quercetin Alleviates Lipopolysaccharide-Induced Cardiac Inflammation via Inhibiting Autophagy and Programmed Cell Death

Objective The aim of this study is to explore the potential modulatory role of quercetin against Endotoxin or lipopolysaccharide(LPS)induced septic cardiac dysfunction.Methods Specific pathogen-free chicken embryos(n=120)were allocated untreated control,phosphate buffer solution(PBS)vehicle,PBS with ethanol vehicle,LPS(500 ng/egg),LPS with quercetin treatment(10,20,or 40 nmol/egg,respectively),Quercetin groups(10,20,or 40 nmol/egg).Fifteenday-old embryonated eggs were inoculated with abovementioned solutions via the allantoic cavity.At embryonic day 19,the hearts of the embryos were collected for histopathological examination,RNA extraction,real-time polymerase chain reaction,immunohistochemical investigations,and Western blotting.Results They demonstrated that the heart presented inflammatory responses after LPS induction.The LPS-induced higher mRNA expressions of inflammation-related factors(TLR4,TNFα,MYD88,NF-κB1,IFNγ,IL-1β,IL-8,IL-6,IL-10,p38,MMP3,and MMP9)were blocked by quercetin with three dosages.Quercetin significantly decreased immunopositivity to TLR4 and MMP9 in the treatment group when compared with the LPS group.Quercetin significantly decreased protein expressions of TLR4,IFNγ,MMP3,and MMP9 when compared with the LPS group.Quercetin treatment prevented LPS-induced increase in the mRNA expression of Claudin 1 and ZO-1,and significantly decreased protein expression of claudin 1 when compared with the LPS group.Quercetin significantly downregulated autophagyrelated gene expressions(PPARα,SGLT1,APOA4,AMPKα1,AMPKα2,ATG5,ATG7,Beclin-1,and LC3B)and programmed cell death(Fas,Bcl-2,CASP1,CASP12,CASP3,and RIPK1)after LPS induction.Quercetin significantly decreased immunopositivity to APOA4,AMPKα2,and LC3-II/LC3-I in the treatment group when compared with the LPS group.Quercetin significantly decreased protein expressions of AMPKα1,LC3-I,and LC3-II.Quercetin significantly decreased the protein expression to CASP1 and CASP3 by immunohistochemical investigation or Western blotting in treatment group when compared with LPS group.Conclusion Quercetin alleviates cardiac inflammation induced by LPS through modulating autophagy,programmed cell death,and myocardiocytes permeability.

New perspectives on the therapeutic potential of quercetin in non-communicable diseases:Targeting Nrf2 to counteract oxidative stress and inflammation

Non-communicable diseases(NCDs),including cardiovascular diseases,cancer,metabolic diseases,and skeletal diseases,pose significant challenges to public health worldwide.The complex pathogenesis of these diseases is closely linked to oxidative stress and inflammatory damage.Nuclear factor erythroid 2-related factor 2(Nrf2),a critical transcription factor,plays an important role in regulating antioxidant and anti-inflammatory responses to protect the cells from oxidative damage and inflammation-mediated injury.Therefore,Nrf2-targeting therapies hold promise for preventing and treating NCDs.Quercetin(Que)is a widely available flavonoid that has significant antioxidant and anti-inflammatory properties.It modulates the Nrf2 signaling pathway to ameliorate oxidative stress and inflammation.Que modulates mitochondrial function,apoptosis,autophagy,and cell damage biomarkers to regulate oxidative stress and inflammation,highlighting its efficacy as a therapeutic agent against NCDs.Here,we discussed,for the first time,the close association between NCD pathogenesis and the Nrf2 signaling pathway,involved in neurodegenerative diseases(NDDs),cardiovascular disease,cancers,organ damage,and bone damage.Furthermore,we reviewed the availability,pharmacokinetics,pharmaceutics,and therapeutic applications of Que in treating NCDs.In addition,we focused on the challenges and prospects for its clinical use.Que represents a promising candidate for the treatment of NCDs due to its Nrf2-targeting properties.

Protective effects of quercetin against H2O2 induced KGN cells injury

Background:Oxidative stress is one of the key contributors to cellular senescence and ovarian aging.Quercetin has a variety of physiological activities such as antioxidant.Given that hydrogen peroxide can cause oxidative damage to cells,the present study is designed to verify the protective effect of quercetin on human ovarian granulosa tumor cell line under oxidative stress.Methods:Cell counting kit-8 and lactate dehydrogenase assays examined cell viability and toxicity.Flow cytometry detected reactive oxygen species accumulation.Glutathione level was measured to analyze the oxidation resistance.Cell apoptosis was evaluated by Hoechst 33258 staining,acridine orange/Ethidium Bromide staining and western blot.The mitochondrial structure was observed under a transmission electron microscope.Mitochondrial membrane integrity was detected by JC-1 staining and western blot.Results:Hydrogen peroxide could induce cell injury,promote reactive oxygen species accumulation,and lead to glutathione depletion.hydrogen peroxide also resulted in mitochondrial morphological damage and depolarization,which activate caspase3/9 subsequently.However,quercetin could mitigate these damages.Conclusions:Present study found that hydrogen peroxide induced oxidative stress and mitochondrial apoptosis of human ovarian granulosa tumor cell line cells,which could be attenuated by quercetin.

Reduction of the oxidative damage to H_(2)O_(2)-induced HepG2 cells via the Nrf2 signalling pathway by plant flavonoids Quercetin and Hyperoside

Hyperoside and quercetin are similar in molecular structures.In this study,the antioxidant regulatory targets of hyperoside and quercetin are mainly in the nuclear factor(erythroid-2-derived)-related factor 2(Nrf2)pathway predicted by network pharmacology.And the antioxidant effect and mechanism of hyperoside and quercetin were measured and compared in H_(2)O_(2)-induced Hep G2 cells and Caenorhabditis elegans.The findings indicated that quercetin was more effective than hyperoside in reducing oxidative damage,which was proved by improved cell viability,decreased reactive oxygen species(ROS)production,decreased cellular apoptosis,and alleviated mitochondrial damage.In addition,quercetin was more efficient than hyperoside in enhancing the expression of Nrf2-associated m RNAs,increasing the activities of superoxide dismutase(SOD),glutathione peroxidase(GSH-Px),and catalase(CAT),and reducing the cellular malondialdehyde(MDA)content.Quercetin was superior to hyperoside in prolonging the lifespan of worms,decreasing the accumulation of lipofuscin,inhibiting ROS production,and increasing the proportion of skn-1 in the nucleus.With the Nrf2 inhibitor ML385,we verified that quercetin and hyperoside primarily protected the cells against oxidative damage via the Nrf2 signalling pathway.Furthermore,molecular docking and dynamics simulations demonstrated that the quercetin-Kelch-like ECH-associated protein 1(Keap1)complex was more stable than the hyperoside-Keap1 complex.The stable structure of the complex might hinder the binding of Nrf2 and Keap1 to release Nrf2 and facilitate its entry into the nucleus to play an antioxidant role.Overall,quercetin had a better antioxidant than hyperoside.

Protective mechanism of quercetin compounds against acrylamide-induced hepatotoxicity

Quercetin compounds have antioxidant,anti-inflammatory and anticancer pharmacological functions.Longterm exposure to acrylamide(AA)can cause liver injury and endanger human health.However,whether quercetin compounds can attenuate AA-induced liver injury and the specific mechanism are not clear.Here,we studied the mechanism and structure-activity relationship of quercetin compounds in reducing AA-induced hepatotoxicity in vivo and in vitro.In vivo studies found that quercetin-like compounds protect against AAinduced liver injury by reducing oxidative stress levels,activating the Akt/m TOR signaling pathway to attenuate autophagy,and improving mitochondrial apoptosis and endoplasmic reticulum stress-mediated apoptosis.In vitro studies found that quercetin compounds protected Hep G2 cells from AA by attenuating the activation of AA-induced autophagy,lowering reactive oxygen species(ROS)levels by exerting antioxidant effects and thus attenuating oxidative stress,increasing mitochondrial membrane potential(MMP),and improving apoptosis-related proteins,thus attenuating AA-induced apoptosis.Furthermore,the conformational differences between quercetin compounds correlated with their protective capacity against AA-induced hepatotoxicity,with quercetin showing the best protective capacity due to its strongest antioxidant activity.In conclusion,quercetin compounds can protect against AA-induced liver injury through multiple pathways of oxidative stress,autophagy and apoptosis,and their protective capacity correlates with antioxidant activity.

Identification of key genes regulating the synthesis of quercetin derivatives in Rosa roxburghii through integrated transcriptomics and metabolomics

Rosa roxburghii fruit is rich in flavonoids, but little is known about their biosynthetic pathways. In this study, we employed transcriptomics and metabolomics to study changes related to the flavonoids at five different stages of R. roxburghii fruit development. Flavonoids and the genes related to their biosynthesis were found to undergo significant changes in abundance across different developmental stages, and numerous quercetin derivatives were identified. We found three gene expression modules that were significantly associated with the abundances of the different flavonoids in R. roxburghii and identified three structural UDP-glycosyltransferase genes directly involved in the synthesis of quercetin derivatives within these modules. In addition, we found that RrBEH4, RrLBD1 and RrPIF8could significantly increase the expression of downstream quercetin derivative biosynthesis genes. Taken together,these results provide new insights into the metabolism of flavonoids and the accumulation of quercetin derivatives in R. roxburghii.

Effects of Quercetin Extracted from Flower Buds of Sophora japonica cv.jinhuai on Proliferation and Apoptosis of Human Breast Cancer MCF-7 Cells

[Objectives]To investigate the effects of quercetin extracted from flower buds of Sophora japonica cv.jinhuai on the proliferation,apoptosis and migration of human breast cancer MCF-7 cells.[Methods]MTT assay,inverted microscope observation,hoechst33342 staining,flow cytometry(FCM)and wound healing assay were adopted to investigate the proliferation,morphological changes,apoptosis level and cell migration ability of human breast cancer MCF-7 cells,respectively.[Results]The morphological changes of cells in the treatment groups included gradually decreased number,reduced volume,vague cell contour,loose intercellular connection,uneven cytoplasm distribution and increased cell debris.With the increase of drug concentration,quercetin significantly inhibited the proliferation of human breast cancer MCF-7 cells(P<0.05).The number of apoptotic bodies increased gradually.When the concentration reached 100μmol/L,a large number of nuclear fragments appeared,and the level of apoptosis was statistically different(P<0.05).The mobility and migration ability of cells showed a decreasing trend,and the differences were statistically significant(P<0.05).[Conclusions]This study can provide experimental basis for clinical application of quercetin against breast cancer.

Quercetin regulates depression-like behavior in CUMS rat models via TLR4/NF-κB signaling

Background:Depression is becoming increasingly prevalent around the world,imposing a substantial burden on individuals,families,as well as society.Quercetin is known to be highly effective in treating depression.However,additional research is needed to dissect the mechanisms of its anti-depressive effects.Methods:For this study,Sprague-Dawley(SD)rats were randomized into the control,model,quercetin,or fluoxetine group.The latter three groups were exposed to chronic unpredictable mild stress(CUMS)for 42 d.The first two groups received saline solution daily via oral gavage.Meanwhile,the quercetin group was orally administered a quercetin suspension(52.08 mg/kg)every day,while the fluoxetine group was orally administered a fluoxetine solution(2.08 mg/kg).Here,fluoxetine served as the positive control drug to compare the therapeutic effects of quercetin.The experimental period was 6 weeks.Depressive behaviors in rats were assessed through various physiological and behavioral measures.Additionally,pathological changes in hippocampal tissues were examined using Nissl staining.Serum cytokines were detected using an enzymelinked immunosorbent assay(ELISA),and immunohistochemistry was employed to quantify the levels and integral optical density(IOD)values of ionized calcium binding adaptor molecule-1(Iba-1)expression in the brain.Real-time fluorescence quantitative PCR(RT-qPCR)was utilized to evaluate the mRNA levels of inflammatory indicators as well as toll-like receptor 4(TLR4),and nuclear factor-κappa B P65(NF-κB P65)in hippocampus.Western blot(WB)technique was employed to observe the protein levels of TLR4,NF-κB P65,and phospho-NF-κB P65(p-NF-κB P65).Results:After 42 d of exposure to CUMS,rats exhibited a slow increase in body weight,a reduction in food intake,an abnormal preference for sugar water,and aberrant open-field behaviors.Pathological analysis revealed the disintegration,rupture,interruption,and disorganization of hippocampal neuronal cells after CUMS exposure,along with a decrease in Nissl bodies in the CA1 region.This was accompanied by the elevated expression of interleukin-1β(IL-1β),tumor necrosis factor-α(TNF-α),and interleukin-6(IL-6)in the serum and the upregulation of IL-1β,IL-6,and TNF-αmRNA expression in the hippocampus.Increases in Iba-1-positive cells and the IOD values of Iba-1 were detected in hippocampal microglia.Furthermore,TLR4 and NF-κB P65 mRNA and protein levels were upregulated in hippocampal tissues.Quercetin,an antidepressant,could alleviate depression-like symptoms in rats and downregulate inflammatory factors associated with the TLR4/NF-κB signaling pathway in hippocampal microglia,and its therapeutic effect was comparable to fluoxetine.Conclusion:In rat models of CUMS,quercetin may act as an antidepressant by inhibiting inflammation in hippocampal microglia via TLR4/NF-κB signaling pathway.These results offer experimental and theoretical support for applying quercetin in the clinical management of depression.

Based on network pharmacology,molecular docking and experimental validation to reveal the potential molecular mechanism of quercetin for the treatment of diarrheal irritable bowel syndrome

Objective:To explore the potential mechanism of action of quercetin in the treatment of diarrhea irritable bowel syndrome(IBS-D).Methods:The potential targets of quercetin were obtained from the TCMSP,SwissTar-getPrediction,and BATMAN-TCM databases.The targets of IBS-D were obtained by searching the GeneCards database with"diarrhea irritable bowel syndrome"as the keyword,and the targets of quercetin and IBS-D were intersected.The PPI network was constructed by Cytoscape 3.7.1 software.The intersected targets were imported into the DAVID database for GO functional analysis and KEGG pathway enrichment analysis.The binding ability of quercetin to the core targets was observed using molecular docking.Based on this,we established an IBS-D rat model,administered quercetin for intervention,and experimentally validated the network pharmacology prediction results by HE staining and ELISA assay.Results:Network pharmacology analysis showed that TP53,TNF-α,AKT1,VEGF-A,IL-6 factors and MAPK,PI3K-Akt signaling pathway as the core targets and pathways of quercetin for the treatment of IBS-D.The results of animal experiments revealed that quercetin could inhibit the secretion of TP53,TNF-α,AKT1,VEGF-A,IL-1βand IL-6,reduce the inflammatory response and improve IBS-D.Conclusion:Quercetin could protect colon tissue by regulating the expression of TP53,TNF-α,AKT1,VEGF-A,IL-1βand IL-6,thereby treating IBS-D.

Quercetin inhibits truncated isoform of dopamine-and cAMP-regulated phosphoprotein as adjuvant treatment for trastuzumab therapy resistance in HER2-positive breast cancer

Trastuzumab resistance is one of the causes of poor prognosis in patients with human epidermal growth factor receptor 2(HER2)-positive(HER2+)breast cancer(BC).The truncated isoform of dopamine-and cAMPregulated phosphoprotein(t-DARPP)has been reported to be involved in trastuzumab therapy resistance and promoting tumor progression.To evaluate the t-DARPP expression in BC,paired tumors and surrounding normal tissues were analyzed by real-time polymerase chain reaction and confirmed higher DARPP-32 kDa family mRNA expression in HER2+BC tumor tissues.We established 2 patient-derived xenografts(PDX)mice models to test the efficacy of trastuzumab,named model 1(non-responder)and model 2(responder).t-DARPP and p95-HER2 protein-protein interactions were detected in PDX tumor tissue from non-responders using Förster resonance energy transfer assays.Instead,there is no response from the responder.Furthermore,mechanistic studies using transwell and western blot assays demonstrated that t-DARPP could upregulate epithelial-mesenchymal transition signaling proteins,enhance p95-HER2 expression and promote cell migration.We found that quercetin effectively reduced t-DARPP expression in HER2+BC cells.In t-DARPP ShRNA-suppressed cells,quercetin synergistically enhanced trastuzumab-induced apoptotic cell death and G2/M phase arrest.In conclusion,the combination of quercetin and trastuzumab treatment by targeting t-DARPP in HER2+BC patients has the potential as a biomarker for mitigating drug resistance.

Quercetin调节肝癌HepG2细胞Fas表达诱导细胞凋亡

目的:探讨三磷酸肌醇(IP3)和Fas基因表达变化在quercetin诱导肝癌细胞凋亡中的作用。方法:以肝癌HepG2细胞培养72h为对照,20、40、60、80μmol/L quercetin作用于HepG2细胞72h和60μmol/Lquercetin作用于HepG2细胞6h、12h、24h、48h、72h,应用同位素试剂盒IP3-[3H]Birtrak检测细胞IP3含量,RT-PCR分析FasmRNA表达,Western blotting分析细胞Fas蛋白表达,流式细胞仪检测细胞凋亡率。结果:各浓度的quercetin作用于肝癌HepG2细胞72h,IP3含量显著低于对照组[(17.9±1.5)pmol/106cells、(15.5±1.1)pmol/106cells、(5.7±0.9)pmol/106cells、(5.5±0.8)pmol/106cellsvs(29.4±0.5)pmol/106cells],FasmRNA表达显著高于对照组[RI0.26±0.01、0.30±0.01、0.30±0.02、0.37±0.02vs0.19±0.02],Fas蛋白表达显著高于对照组[RI(灰度与面积之积的相对强度)1.10±0.08、0.91±0.02、0.78±0.07、0.73±0.05vs0.15±0.01],细胞凋亡率显著高于对照组[(11.2±1.1)%、(15.5±1.1)%、(26.8±2.5)%、(27.1±1.5)%vs(2.6±0.1)%];60μmol/L quercetin作用于肝癌HepG2细胞6h、12h、24h、48h、72h,各时相IP3含量显著低于对照组[(23.3±1.4)pmol/106cells、(12.0±1.4)pmol/106cells、(7.5±0.8)pmol/106cells、(5.6±0.5)pmol/106cells、(4.3±0.6)pmol/106cellsvs(29.2±0.6)pmol/106cells,P<0.01];12h后FasmRNA表达显著高于对照组[RI0.26±0.02、0.28±0.02、0.26±0.01、0.24±0.01vs0.20±0.01],Fas蛋白表达显著高于对照组[RI0.65±0.17、1.20±0.07、1.51±0.06、1.50±0.06、0.97±0.17vs0.18±0.01],24h后各时相细胞凋亡率显著高于对照组[(7.4±0.5)%、(20.5±2.0)%、(30.7±1.6)%vs(2.6±0.1)%,P<0.01]。结论:Quercetin能减少IP生成,上调Fas基因表达,诱导肝癌细胞凋亡。

负载槲皮素的羧甲基壳聚糖水凝胶促进糖尿病大鼠创面愈合

背景:槲皮素具有抗炎、抗癌、抗氧化、抗衰老、抗抑郁等药理作用,具有极高的药用价值。槲皮素可以促进正常大鼠创面的愈合,但是以槲皮素为主要成分的药物研发较少,限制了其在临床的广泛应用。目的:以水凝胶材料负载槲皮素,探讨槲皮素-羧甲基壳聚糖水凝胶在糖尿病大鼠创面中的应用效果。方法:①分别制备羧甲基壳聚糖水凝胶与槲皮素-羧甲基壳聚糖水凝胶,表征水凝胶的微观形貌、体外释药性能。②细胞实验:将小鼠L929成纤维细胞分4组培养,空白对照组常规培养,纯水凝胶组、药物组、载药水凝胶组分别加入羧甲基壳聚糖水凝胶、槲皮素溶液与槲皮素-羧甲基壳聚糖水凝胶,检测细胞增殖与迁移能力。③动物实验:取80只SD大鼠建立糖尿病模型,造模成功后在大鼠背部制作直径2 cm的全层皮肤缺损创面,随机分4组干预,空白对照组、纯水凝胶组、药物组、载药水凝胶组创面分别注射生理盐水、羧甲基壳聚糖水凝胶、槲皮素溶液、槲皮素-羧甲基壳聚糖水凝胶,每组20只,无菌纱布包扎固定。术后观察创面愈合情况、创面病理形态、炎症因子表达及血管生成情况。结果与结论:①扫描电镜下可见两种水凝胶的微观形貌相似,均呈疏松多孔的网络结构,并且槲皮素-羧甲基壳聚糖水凝胶具有良好的体外释药性能。②与空白对照组比较,其他3组细胞增殖与迁移率升高(P<0.05);载药水凝胶组细胞增殖与迁移率高于纯水凝胶组、药物组(P<0.05)。③载药水凝胶组大鼠术后5,11 d的创面愈合率高于其他3组;载药水凝胶组、纯水凝胶组、药物组大鼠术后18 d的创面愈合率基本达到100%,均高于空白对照组(P<0.05)。苏木精-伊红染色显示,载药水凝胶组大鼠术后18 d创面可见完整的皮肤与皮肤附属器,空白对照组、纯水凝胶组、药物组大鼠术后25 d创面可见完整的皮肤与皮肤附属器。载药水凝胶组大鼠创面术后5,11,18 d的创面肿瘤坏死因子α、白细胞介素6水平均低于空白对照组(P<0.05),术后11,18 d的创面转化生长因子β1水平低于空白对照组(P<0.05)。载药水凝胶组大鼠术后11,18 d的CD31、血管内皮生长因子αmRNA表达量均高于其他3组(P<0.05)。④结果表明,槲皮素-羧甲基壳聚糖水凝胶中的槲皮素可发挥调节炎症反应、促进血管新生的作用,可通过促进成纤维细胞的增殖与迁移,促进糖尿病大鼠创面的愈合。

Quercetin对HepG_2细胞的抑制作用及PDGFR-β的表达

目的 探讨植物化学物质槲皮素 (Quercetin)对人类肝癌细胞HepG2 的抑制作用和血小板衍生生长因子 β受体 (PDGFR β)表达的关系。 方法 采用免疫组化SABC法观察Quercetin抑制HepG2 中PDGFR β表达 ,并采用透射电镜观察Quercetin作用后HepG2 细胞的凋亡情况。结果 细胞增殖率检测表明Quercetin可以抑制HepG2 细胞的增殖 ,且呈剂量依赖性 ;Quercetin可以抑制HepG2 细胞PDGFR β的表达 ,且呈剂量依赖性 ;透射电镜下可见凋亡小体。结论 槲皮素对HepG2 细胞增殖有明显抑制作用 ,其机制可能是诱导PDGFR β的增加 ,再通过PDGFR

Preparation and Physicochemical Characterization of Quercetin-HP-β-CD Inclusion Complexes

Aim To prepare and characterize the QURC-HP-β-CD inclusion complexes and investigate the thermodynamic parameters of the process. Methods QURC-HP-β-CD inclusion complexes were prepared by the grinding method. The equilibrium inclusion constants and thermodynamic parameters were determinated by phase solubility analysis. Dissolution tests were performed to study the dissolution rate of inclusion complexes. The formation of inclusion complexes was confirmed by differential scanning calorimetry （ DSC）, infrared spectroscopy （IR） , powder X-ray diffractometry （PXRD） and scanning electron microscopy （SEM）. Results The aqueous solubility of quercetin was greatly increased （ about 37 folds） by inclusion technique, and the initial dissolution rate was markedly improved （10 folds） in the first 5 min. The results of DSC and SEM photographs showed that quercetin crystal disappeared in inclusion complexes, which indicated the formation of new phase. FT-IR spectra showed that the carbonyl quercetin crystal grinding method. absorption band of quercetin was shifted. PXRD showed that the diffraction peak of disappeared. Conclusion QURC-HP-β-CD inclusion complexes are produced by the The solubility of quercetin is improved by the inclusion technique.

Effect of Quercetin on CYP1A2, CYP2E1, CYP3A2 Activities and its Inhibitory Mechanism Studies in Rat Liver Microsomes

Aim To assess the potential effect of quercetin （QU）, an natural plant estrogen, on CYP1A2, CYP2E1, and CYP3A2 activities in rat liver microsomes; and to identify the magnitude of inhibitory effect and the probable inhibitory mechanism of QU. Methods QU and specific substrate were concurrently incubated, with HPLC detection of the substrate metabolites for data analysis. The magnitude of inhibitory effect of QU on CYP3A2 was compared with those of ketoconazole （Ket） and erythromycin （Ery）. The mechanism of its inhibitory effect on CYP3A2 and CYP2E1 was derived from Lineweaver-Burk plots. Results HPLC methods were in good linear relationship with r〉0.999 1. Relative standard deviations for intra-day and inter-day were〈8.4%. Recovery of each analyte in the concentrations studied was between 91.1% and 107.6 %. QU （up to 8 μmol·L^-1） showed potent induction to CYP1A2 （338.1% of the negative control）while inhibited CYP2E1 （49.2% of the negative control） and CYP3A2 （60.3% of the negative control） activity. The magnitude of inhibitory effect for QU on CYP3A2 was between those for Ket and Ery （Ket〉QU〉Ery）. QU exhibited competitive inhibition of CYP3A2 dextromethorphan N-demethylation reaction and expressed noncompetitive inhibition of CYP2E1 chlorzoxazone-6-hydroxylation reaction. Conclusion HPLC assay has been validated with precision and accuracy. QU is an effective inhibitor of several CYP isoforms. It may cause relevant drug-drug interactions with CYP3A substrates. As a plant flavonoid, QU has potential not only in molecular advantage but also in CYP450 module capability for further application in cancer chemotherapy.

Effect of Quercetin on the Proliferation and Mitochondrial Transmembrane Potential of CBRH-7919 Cells

[Objective] To investigate the effect of quercetin on the proliferation and mitochondrial transmembrane potential of CBRH-7919 cells. [Method] The CBRH-7919 cells of hepatocarcinoma were cultured in vitro. After treated with different concentrations of quercetin, the OD405 nm of CBRH-7919 cells was detected by using the acid phosphatase assy （APA）; morphologic changes of the cells were observed under inverted microscope; the mitochondrial transmembrane potential （△ψm） intensity changes of CBRH-7919 cells were analyzed by flow cytometry after stained with Rhodamine 123. [Result] Quercetin inhibited the proliferation of CBRH-7919 cells significantly, and the growth inhibitory effect presented time- and dose-dependent relationship. Typical decrease of cell density was observed by optical microscopy on the quercetin-treated cells. With the effect of 10 μg/ml quercetin on CBRH-7919 cells for 12, 24 and 48 h, the percentage of Rhodamine 123 stained hypofluorescence cells increased, while the mitochondrial transmembrane potential（△ψm） intensity of CBRH-7919 cells decreased. [Conclusion] Quercetin could inhibit the proliferation of CBRH-7919 cells in vitro, causing the decrease in mitochondrial transmembrane potential.

Quercetin调节肝癌HepG2细胞PTEN基因表达诱导细胞凋亡的实验研究

目的探讨三磷酸肌醇(IP3)和PTEN基因表达变化在quercetin诱导肝癌细胞凋亡中的作用。方法以肝癌HepG2细胞为空白对照,以不同浓度quercetin作用于HepG2细胞不同时间后,应用同位素试剂盒检测细胞IP3含量,RT-PCR分析PTENmRNA表达,Western blotting分析细胞PTEN蛋白表达,流式细胞仪检测细胞凋亡率。结果各浓度的quercetin作用于肝癌HepG2细胞,IP3含量显著低于对照组(17.9±1.5、15.5±1.1、5.7±0.9、5.5±0.8vs29.4±0.5),PTENmRNA表达与对照组无显著差异,PTEN蛋白表达显著高于对照组(0.55±0.02、0.67±0.02、0.94±0.04、0.95±0.03vs0.02±0.002),细胞凋亡率显著高于对照组。60μmol/Lquercetin作用于肝癌HepG2细胞6h、12h、24h、48h、72h,各时相IP3含量显著低于对照组(23.3±1.4、12.0±1.4、7.5±0.8、5.6±0.5、4.3±0.6vs29.2±0.6,P<0.01)。PTENmRNA表达与对照组无显著差异,12h后各时项PTEN蛋白表达显著高于对照组,24h后各时相细胞凋亡率为显著高于对照组(P<0.01)。结论Quercetin能减少IP3生成,上调PTEN蛋白,诱导肝癌细胞凋亡。

Quercetin对晶状体上皮细胞HSP70、HSP27表达的调节作用

目的研究大鼠眼钝挫伤后晶状体上皮细胞(LECs)热休克蛋白(HSP)70、HSP27的表达,并给予喂饲Quercetin(HSP阻滞剂),观察Quercetin对LECsHSP70及HSP27表达的调节。方法SD大鼠48只,随机分成拍打组和Quercetin组,每组各24只24眼,右眼为实验眼。拍打组:20g铁球20cm高度拍打眼球100次。Quercetin组:给大鼠喂饲Quercetin(100mg/kg),2-3h后再拍打眼球。RT-PCR检测LECsHSP70、HSP27基因表达。结果钝挫性眼外伤可造成LECsHSP70基因表达的增强,拍打眼球后1hHSP70表达开始升高,3h后达到高峰,24h后降至正常。Quercetin组HSP70基因表达随时间亦出现相应的提高,但与拍打组相比其峰值下降,差异有非常显著性意义。两组HSP27基因表达均无明显改变。结论钝挫性眼外伤中LECsHSP70表达的增强提示HSP70可能在钝挫性外伤性白内障形成过程中对晶状体变性蛋白起保护作用,预先喂饲Quercetin可抑制LECsHSP70基因的表达,其作用机制可能发生于HSP转录水平。