槲皮素对宫颈癌细胞C33A增殖和凋亡的影响

目的 观察槲皮素对人宫颈癌细胞C33A增殖和凋亡的影响,初步探讨其相关作用机制。方法 用不同浓度槲皮素（空白对照、20、40、80 μmol/L）,顺铂（空白对照、5、10、15、20 μg/mL）以及两者联合（槲皮素40 μmol/L+顺铂 10 μg/mL）分别作用于C33A细胞24 h和48 h后,噻唑蓝（MTT法）检测细胞活力的变化;流式细胞术检测槲皮素对C33A细胞周期的影响;Western blot检测槲皮素对C33A细胞Cyclin D1、Caspase-3和Caspase-9蛋白表达的影响。结果 MTT结果显示,经过槲皮素处理24 h后,各组细胞活力分别为86.92±3.953）%（20 μmol/L组）、（66.54±3.932）%（40 μmol/L组）和 （52.21±2.970）%（80 μmol/L组）,均低于空白对照组的（98.35±1.230）% ;经过槲皮素处理48 h后,各组细胞活力分别为（65.19±7.071）%（20 μmol/L组）、（47.04±8.881）%（40 μmol/L组）和 （29.71±6.505）%（80 μmol/L组）,均低于空白对照组的（96.97±1.788）%。;此外,槲皮素40 μmol/L+顺铂 10 μg/mL联合作用于C33A细胞24h后,细胞活力下降为（31.12±2.835）%; 48 h后,细胞活力下降为（17.86±3.182）%,同空白对照组相比均出现了明显的下降,（31.12±2.835）%; 48 h后,细胞活力下降为（17.86±3.182）%（P<0.05）。细胞周期检测结果显示,槲皮素可增加C33A细胞G₀/G₁期数量,减少S期数量。Western blot结果显示,槲皮素可下调C33A细胞Cyclin D1蛋白的表达,还可上调Caspase-3和Caspase-9蛋白的表达。结论 槲皮素通过下调Cyclin D1蛋白的表达可以抑制C33A细胞的活力和增殖,槲皮素通过上调Caspase-3和Caspase-9蛋白的表达,可以诱导C33A细胞的凋亡。     

结直肠癌中葡萄糖转运蛋白-12作为化疗联合用药靶点的研究

目的 研究葡萄糖转运蛋白-12（GLUT12）在结直肠癌（CRC）细胞和组织中的表达与功能,探讨其作为联合用药治疗靶点的可能性。方法 分别采用RT-PCR和蛋白免疫印迹法检测CRC及正常结肠中GLUT12基因和蛋白水平。通过荧光免疫及蛋白印迹法观察槲皮素（QC）对肿瘤细胞中GLUT12定位的调节作用。四氮唑（MTT）比色法和克隆形成实验（CFA）观察QC和奥沙利铂（OXA）联合使用对CRC细胞增殖的影响。结果 GLUT12基因在肿瘤组织中的相对表达水平高于正常组织[（3.2±0.3）vs（0.5±0.6）,P<0.05]。高糖培养液能改变GLUT12在细胞中的定位及表达水平,QC能抑制高糖对GLUT12蛋白的调节作用。MTT和CFA试验显示,OXA和QC联用能使CRC细胞的活力降低[OXA+OC：（63.3±7.1）%vs OC：（88.7±4.2）%,P< 0.05]。QC和OXA联用能抑制结肠癌细胞群落的增殖能力。结论 QC能有效抑制CRC细胞GLUT12蛋白的功能,能增加OXA杀伤CRC的作用。     

Quercetin attenuates domoic acid-induced cognitive deficits in mice

Domoic acid (DA) is one of the best known marine toxins, causative of important neurotoxic alterations. DA effects are documented both in wildlife and experimental assays, showing that this toxin causes severe injuries principally in the hippocampal area. Accumulating evidence indicates that mitochondrial dysfunction and oxidative stress are involved in DA-induced cognitive functional impairment. Therefore, therapeutics targeted to improve mitochondrial function and increase oxidative stress defence could be bene?cial. Quercetin, a bio?avanoid, has been reported to have potent neuroprotective effects and anti-oxidative ability, but its preventive effects on DA-induced mitochondrial dysfunction and cognitive impairment have not been well characterised. In this study, we evaluated the effects of quercetin on DA-induced cognitive deficits in mice and explored its potential mechanism. Our results showed that the oral administration of quercetin to DA-treated mice significantly improved their behavioural performance in a novel objective recognition task and a Morris water maze task. These improvements were mediated, at least in part, by a stimulation of PPARγ coactivator 1α-mediated mitochondrial biogenesis signalling and an amelioration of mitochondrial dysfunction. Moreover, quercetin activated nuclear factorerythroid-2-related factor-2 (Nrf2)-mediated phase II enzymes and decreased reactive oxygen species and protein carbonylation. Furthermore, the AMP-activated protein kinase (AMPK) activity significantly increased in the quercetin-treated group. Taken together, these findings suggest that a reduction in mitochondrial dysfunction through the increase of AMPK activity, coupled with an increase in Nrf2 pathway mediated oxidative defence, may be one of the mechanisms by which quercetin improves cognitive impairment induced by DA in mice.     

基于网络药理学方法赤芍-牡丹皮药对治疗中风作用机制探讨

目的:采用网络药理学的分析方法研究赤芍-牡丹皮经典药对治疗中风的分子作用机制。方法:基于中药系统药理数据库和分析平台(TCMSP)、药物与疾病数据库(Drug Bank)、赤芍-牡丹皮的疾病与化学成分靶点网络则分别由治疗靶标数据库(TTD)建立,而它的药效成分与靶点网络主要运用Cytoscape 3.7.0软件构建而成,并同时进行了网络拓补分析; 至于核心靶点对基因本体(GO)的功能富集则主要运用DAVID数据库完成,同时也对百科全书KEGG(基因组)通路的功能富集进行了研究。结果:网络拓补分析结果表明,最核心的药效成分可能为槲皮素、山奈酚、鞣花酸、黄芩苷,最核心的GO功能有活性氧代谢过程、脂多糖、核受体活性、细胞因子受体结合、细胞膜微区、囊腔作用等; 最核心的作用通路有VERF通路、Toll样受体通路、肿瘤坏死因子(TNF)通路、白细胞介素-17(IL-17)信号通路、磷脂酰肌醇3激酶-蛋白激酶b(P13K-Akt)通路等。结论:本文基于网络药理学方法对赤芍-牡丹皮药对干预中风的作用机制进行了分析发现,赤芍-牡丹皮药对可能是通过VERF通路、Toll样受体通路、TNF通路、IL-17信号通路、P13K-Akt等通路协同作用发挥治疗缓解中风功效,上述预测结果可为赤芍-牡丹皮药对在中风治疗的药理作用研究及临床应用提供一定的理论依据。     

A physiologically based kinetic (PBK) model describing plasma concentrations of quercetin and its metabolites in rats

Biological activities of flavonoids in vivo are ultimately dependent on the systemic bioavailability of the aglycones as well as their metabolites. In the present study, a physiologically based kinetic (PBK) model was developed to predict plasma concentrations of the flavonoid quercetin and its metabolites and to tentatively identify the regiospecificity of the major circulating metabolites. The model was developed based on in vitro metabolic parameters and by fitting kinetic parameters to literature available in vivo data. Both exposure to quercetin aglycone and to quercetin-4′-O-glucoside, for which in vivo data were available, were simulated. The predicted plasma concentrations of different metabolites adequately matched literature reported plasma concentrations of these metabolites in rats exposed to 4′-O-glucoside. The bioavailability of aglycone was predicted to be very low ranging from 0.004%-0.1% at different oral doses of quercetin or quercetin-4′-O-glucoside. Glucuronidation was a crucial pathway that limited the bioavailability of the aglycone, with 95–99% of the dose being converted to monoglucuronides within 1.5–2.5 h at different dose levels ranging from 0.1 to 50 mg/kg bw quercetin or quercetin-4′-O-glucoside. The fast metabolic conversion to monoglucuronides allowed these metabolites to further conjugate to di- and tri-conjugates. The regiospecificity of major circulating metabolites was observed to be dose-dependent. As we still lack in vivo kinetic data for many flavonoids, the developed model has a great potential to be used as a platform to build PBK models for other flavonoids as well as to predict the kinetics of flavonoids in humans.     

HPLC法同时测定铁包金不同药用部位中芦丁和槲皮素的含量

目的:建立同时测定铁包金不同药用部位芦丁、槲皮素含量的方法。方法:采用高效液相色谱法。色谱柱为迪马ODS C18(250 mm×4.6 mm,5μm),流动相为乙腈-甲醇-0.2%磷酸(梯度洗脱),流速为0.9 ml/min,柱温为30℃,检测波长为360 nm。结果:芦丁和槲皮素的进样量分别在0.01¹.88、0.011.88、0.01⁰.23μg范围内与各自峰面积积分值呈良好线性关系;精密度、稳定性、重复性的RSD<2%;芦丁、槲皮素的平均加样回收率分别为99.48%、102.34%,RSD分别为2.06%、2.37%(n=6)。结论:铁包金叶与藤茎部位中芦丁、槲皮素的含量均较高。该方法简单、稳定,结果准确、可靠,可用于铁包金的质量控制。     

Quercetin protects cardiomyocytes against doxorubicin-induced toxicity by suppressing oxidative stress and improving mitochondrial function via 14-3-3γ

Cardiotoxicity limits the clinical applications of doxorubicin (Dox), which mechanism might be excess generation of intracellular ROS. Quercetin (Que) is a flavonoid that possesses anti-oxidative activities, exerts myocardial protection. We hypothesized that the cardioprotection against Dox injury of Que involved 14-3-3γ, and mitochondria. To investigate the hypothesis, we treated primary cardiomyocytes with Dox and determined the effects of Que pretreatment with or without 14-3-3γ knockdown. We analyzed various cellular and molecular indexes. Our data showed that Que attenuated Dox-induced toxicity in cardiomyocytes by upregulating 14-3-3γ expression. Que pretreatment increased cell viability, SOD, catalase, and GPx activities, GSH levels, MMP and the GSH/GSSG ratio; decreased LDH and caspase-3 activities, MDA and ROS levels, mPTP opening and the percentage of apoptotic cells. However, Que’s cardioprotection were attenuated by knocking down 14-3-3γ expression using pAD/14-3-3γ-shRNA. In conclusion, Que protects cardiomyocytes against Dox injury by suppressing oxidative stress and improving mitochondrial function via 14-3-3γ.     

Quercetin induces morphological and proliferative changes of rat’s uteri under estrogen and progesterone influences

This study investigated the effect of 10 or 100 mg/kg/day quercetin on the uterus of ovariectomized adult female rats receiving sex-steroid replacement regime mimicking changes in hormonal profiles during the reproductive cycle. Following seven days of treatment with estrogen and progesterone with or without quercetin, uteri were harvested for histological and proliferative cell nuclear antigen (PCNA) protein and mRNA expression and PCNA protein distribution analyses. Our findings indicated that co-administration of 10 mg/kg/day quercetin with estrogen and progesterone caused a significant decrease in the size of uterine lumen and epithelial heights with lower PCNA protein and mRNA expression as compared to estrogen plus progesterone-only treatment (P < 0.05). Concomitant treatment with estrogen and progesterone with 100 mg/kg/day quercetin resulted in a marked increase in the number of glands with increased PCNA protein and mRNA expression. Significantly higher PCNA distribution was observed in the stroma and glands as compared to estrogen plus progesterone-only treatment (P < 0.05). In conclusion, at 10 mg/kg/day, quercetin affects uterine morphology but not proliferation, however at 100 mg/kg/day, quercetin induced significant stromal and glandular proliferation which could predispose the uterus towards neoplastic development.     

Electrosorption of quercetin on glassy carbon electrode

The present paper reports a concise study on the mechanism of electrosorption of quercetin (3,3′,4′,5,7-pentahydroxyflavone) molecule on glassy carbon (GC) electrode surface in 0.1 M sodium acetate–acetic acid buffer, in 90% methanol solution. The recorded anodic charge-transients (obtained by injecting small amounts of quercetin-based buffer to initially quercetin-free buffer solution, carried-out at the constant electrode potential) provided for the first time evidence that the process of mutual interaction between quercetin molecules and the surface of glassy carbon electrode is chemisorptive in its nature. Consequently, a possible mechanism of this adsorbent/adsorbate interaction was proposed.     

Hot-melt extrusion microencapsulation of quercetin for taste-masking

Besides its poor dissolution rate, the bitterness of quercetin also poses a challenge for further development. Using carnauba wax, shellac or zein as the shell-forming excipient, this work aimed to microencapsulate quercetin by hot-melt extrusion for taste-masking. In comparison with non-encapsulated quercetin, the microencapsulated powders exhibited significantly reduced dissolution in the simulated salivary pH 6.8 medium indicative of their potentially good taste-masking efficiency in the order of zein?>?carnauba wax?>?shellac. In vitro bitterness analysis by electronic tongue confirmed the good taste-masking efficiency of the microencapsulated powders. In vitro digestion results showed that carnauba wax and shellac-microencapsulated powders presented comparable dissolution rate with the pure quercetin in pH 1.0 (gastric) and 6.8 (intestine) medium; while zein-microencapsulated powders exhibited a remarkably slower dissolution rate. Crystallinity of quercetin was slightly reduced after microencapsulation while its chemical structure remained unchanged. Hot-melt extrusion microencapsulation could thus be an attractive technique to produce taste-masked bioactive powders.