纳米脂质体槲皮素诱导人食管癌癌干样细胞凋亡的研究

目的检测纳米脂质体槲皮素对人食管癌癌干样细胞凋亡的诱导作用，并探讨其机制。方法以氯仿-DMSO预溶的脂质体槲皮素经负压旋转蒸发、超声破碎及80nm过滤制备纳米脂质体槲皮素。将其作用于人食管癌细胞系Eca109／9706细胞的生长抑制率（MTT法），及作用后食管癌细胞中羟自由基（OH^-）、NO、PTEN、NF-κB及Caspase-3的表达（免疫组化法）及凋亡率（采用TUNEL法）。检测Eca109／9706细胞中CD133、MDR1的髟双免疫酶标及单、双荧光标记的复合率。结果纳米脂质体槲皮素处理的Eca109／9706细胞的生长抑制率、OH^-、NO、PTEN、NF-KB及Caspase-3表达和凋亡率均显著高于对照组（P〈0.01）。Eca109／9706细胞的的单免疫荧光／单免疫酶标率各为80％及70％，双免疫荧光／双免疫酶标的复合率为30％-43％。结论纳米脂质体槲皮素可诱导Eca109／9706细胞产生氧化应激反应并激活PTEN、NF-κB的转导途径，最终通过Caspase-3诱导细胞凋亡；CD^＋133、MDR1^＋可作为癌干样细胞的标志。     

JAK2/STAT3通路槲皮素对先兆流产大鼠的保胎作用及对激素水平的影响

 目的 探讨槲皮素对先兆流产大鼠的保胎作用和对激素水平的影响。方法 50只妊娠大鼠随机分为正常组、模型组、槲皮素组、AG490组和槲皮素+AG490组,各10只,槲皮素组、AG490组和槲皮素+AG490组分别给予2.5 mg/ml槲皮素、0.5 mg/kg AG490和2.5 mg/ml槲皮素+0.5 mg/kg AG490灌胃干预,1次/d,连续7 d,正常组、模型组灌胃等量生理盐水,妊娠8 d除正常组外其余各组大鼠以米非司酮和米索前列醇建立先兆流产模型,妊娠9 d各组大鼠按原剂量继续灌胃4 d;妊娠14 d处死大鼠,检测血清激素及免疫因子水平,计算流产率、胚胎吸收率和脏器系数,HE染色观察子宫组织形态学变化。结果 与模型组比较,槲皮素组血清雌二醇、β-人绒毛膜促性腺激素(β-HCG)、孕激素、白细胞介素-10(IL-10)水平和子宫组织磷酸化Janus激酶2(p-JAK2)、磷酸化信号传导及转录激活因子3(p-STAT3)蛋白相对表达量升高,血清干扰素-γ(IFN-γ)、肿瘤坏死因子-α(TNF-α)水平降低,卵巢、子宫合重增加,脏器系数升高,流产率、胚胎吸收率降低(P＜0.05),AG490组血清雌二醇、β-HCG、孕激素、IL-10水平和子宫组织p-JAK2、p-STAT3蛋白相对表达量降低,血清IFN-γ、TNF-α水平升高,卵巢、子宫合重减小,脏器系数降低(P＜0.05);与槲皮素组比较,槲皮素+AG490组血清雌二醇、β-HCG、孕激素、IL-10水平和子宫组织p-JAK2、p-STAT3蛋白相对表达量降低,血清IFN-γ、TNF-α水平升高,卵巢、子宫合重减小,脏器系数降低,胚胎吸收率升高(P＜0.05);与AG490组比较,槲皮素+AG490组血清雌二醇、β-HCG、孕激素、IL-10水平和子宫组织p-JAK2、p-STAT3蛋白相对表达量升高,血清IFN-γ、TNF-α水平降低,卵巢、子宫合重增加,脏器系数升高,胚胎吸收率降低(P＜0.05)。结论 槲皮素对先兆流产大鼠具有保胎作用,可提高其激素水平,机制可能与调控JAK2/STAT3通路有关。     

The role of quercetin on the survival of neuron-like PC12 cells and the expression of α-synuclein

Both genetic and environmental factors are important in the pathogenesis of Parkinson's disease. As α-synuclein is a major constituent of Lewy bodies, a pathologic hallmark of Parkinson's disease, genetic aspects of α-synuclein is widely studied. However, the influence of dietary factors such as quercetin on α-synuclein was rarely studied. Herein we aimed to study the neuroprotective role of quercetin against various toxins affecting apoptosis, autophagy and aggresome, and the role of quercetin on α-synuclein expression. PC12 cells were pre-treated with quercetin(100, 500, 1,000 μM) and then together with various drugs such as 1-methyl-4-phenylpyridinium(MPP+; a free radical generator), 6-hydroxydopamine(6-OHDA; a free radical generator), ammonium chloride(an autophagy inhibitor), and nocodazole(an aggresome inhibitor). Cell viability was determined using a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltertazolium bromide(MTT) assay. Apoptosis was detected by annexin V-fluorescein isothiocyanate and propidium iodide through the use of fluorescence activated cell sorter. α-Synuclein expression was detected by western blot assay and immunohistochemistry. The role of α-synuclein was further studied by knocking out α-synuclein using RNA interference. Cell viability increased at lower concentrations(100 and 500 μM) of quercetin but decreased at higher concentration(1,000 μM). Quercetin exerted neuroprotective effect against MPP+, ammonium chloride and nocodazole at 100 μM. MPP+ induced apoptosis was decreased by 100 μM quercetin. Quercetin treatment increased α-synuclein expression. However, knocking out α-synuclein exerted no significant effect on cell survival. In conclusion, quercetin is neuroprotective against toxic agents via affecting various mechanisms such as apoptosis, autophagy and aggresome. Because α-synuclein expression is increased by quercetin, the role of quercetin as an environmental factor in Parkinson's disease pathogenesis needs further investigation.     

槲皮素、别嘌醇对高尿酸血症大鼠血清尿酸水平及肝、肾功能影响的对比研究

对比研究槲皮素、别嘌醇对高尿酸血症大鼠的治疗作用并观察对肝、肾功能的影响。雄性SD大鼠,连续灌胃给药7 d,第5天采用次黄嘌呤法制备大鼠高尿酸血症模型。采用比色法、连续监测法、化学氧化法、酶联免疫吸附法等测定大鼠血清中尿酸(UA)、丙氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶(AST)、总胆红素(TBIL)、直接胆红素(DBIL)、β₂-微球蛋白(β₂-MG)、胱抑素C(Cys-C)、尿素及肌酐(Cr)含量。结果显示:别嘌醇能够显著降低大鼠血清尿酸水平(P<0.01),而槲皮素对血清尿酸无影响;槲皮素和别嘌醇显著降低大鼠ALT和AST水平(P<0.01),对TBIL和DBIL水平无明显影响,显著提高β₂-MG,Cys-C水平(P<0.01),别嘌醇治疗组大鼠血清尿素和Cr水平明显高于正常对照组(P<0.01);造模组和给药组可见大鼠肾脏轻度病理组织学改变。结果表明:槲皮素对大鼠血清尿酸水平无明显影响,而别嘌醇降尿酸作用显著。造模和给药对肝功能均无明显影响,但造模可能导致肾功能不同程度的损害,槲皮素对轻度肾损伤未见明显的保护作用,别嘌醇给药后加重肾功能损伤。     

槲皮素对大鼠DRG神经元Nav1.8电流的作用及机制

研究槲皮素(Que)对大鼠脊髓背根神经节(DRG)神经元Nav1.8通道电流(I_Nav1.8)的作用。在急性分离的大鼠DRG神经元上,用全细胞膜片钳技术,观察Que干预I_Nav1.8的剂量-反应关系以及Que影响的Nav1.8通道电压依赖的激活和失活特性。结果显示Que(10,30,100 μmol/L)可浓度依赖地抑制DRG神经元I_Nav1.8峰值,峰值抑制率分别为(15.32±3.43)%,(22.92±8.24)%和(47.29±11.42)%,半数抑制浓度(IC₅₀)为121.38 μmol/L,Hill系数为0.76;100 μmol/L Que可使DRG神经元的Nav1.8通道激活曲线向去极化方向偏移了0.83 mV,失活曲线向超极化方向偏移了1.86 mV;且与干预前比,半数失活电压(V_1/2)为-(40.23±0.25)mV,有显著性差异(P<0.01)。说明Que可浓度依赖和电压依赖地抑制DRG神经元Nav1.8通道活性,进而降低痛觉信息的传递,改善慢性内脏痛。     

Inhibition of 5-aminolevulinic acid-induced DNA damage by melatonin, N1-acetyl-N2-formyl-5-methoxykynuramine, quercetin or resveratrol

Porphyrias are defined as either inborn or acquired diseases related to enzymatic deficiencies in the heme biosynthetic pathway. Lead poisoning, hereditary tyrosinemia, and acute intermittent porphyria (AIP) are characterized by the absence of photosensitivity and the accumulation of 5-aminolevulinic acid (ALA) together with its increased urinary excretion. The main clinical manifestations of AIP are intermittent attacks of abdominal pain, neuromuscular weaknesses and neuropsychiatry alterations, and also an association with primary liver cancer, in which may be involved the oxidative potential of ALA which is able to cause DNA damage. The use of antioxidants in the treatment of ALA-induced oxidative stress is not well established. In the current work, we show the antioxidant efficacy of several compounds including melatonin, quercetin, resveratrol and N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK), a melatonin oxidation product, in terms of their ability to limit DNA damage induced by ALA/Fe2+ in an in vitro system. Damage was measured by plasmid DNA strand breaks and detection of 8-oxo, 7-8-dihydro,2'-deoxyguanosine (8-oxodGuo) by high-performance liquid chromatography coupled with electrochemical detection. All compounds tested showed a dose-dependent protective action against free radical damage. These results could be the first step toward studies of the possible use of these antioxidants in oxidative stress promoted by ALA or other pro-oxidants.     

Synergistic effects of snail and quercetin on renal cell carcinoma Caki-2 by altering AKT/mTOR/ERK1/2 signaling pathways

Renal cell carcinoma has become the most common subtype of kidney cancer, and has the highest propensity to manifest as metastatic disease. Because of lack of knowledge in events that correlated with tumor cell migration and invasion, few therapeutic options are available. Therefore, in current study, we explore the anti-tumoral effect of a potential chemopreventive natural product, quercetin, combined with anti-sense oligo gene therapy (inhibiting Snail gene). We found that either one of them had the remarkable effects in suppressing cell proliferation and migration, inducing cell cycle arrest and apoptosis in a ccRCC cell line, Caki-2 cells. The combination of both means provides even strong suppressive effects toward these ccRCC cells. Our study, for the first time, provides the possibility of using a novel treatment for renal cancer, by combining natural product and gene therapy.     

槲皮素对支气管哮喘小鼠气道炎症的作用及机制研究

目的 研究槲皮素是否对支气管哮喘小鼠模型气道炎症具有抑制作用及可能的分子机制。方法 通过腹腔注射卵蛋白（OVA）致敏并行雾化激发复制小鼠支气管哮喘模型。将36只BALB/c雌性小鼠随机分为6组,分别为对照组（CON组）、哮喘模型组（OVA组）、槲皮素低剂量组（LOW组）、槲皮素中剂量组（MID组）、槲皮素高剂量组（HIGH组）剂量组、地塞米松阳性对照组（POS组）。对小鼠哮喘症状的程度进行评分;通过ELISA法检测小鼠支气管肺泡灌洗液（BALF）的上清液中白细胞介素-4（IL-4）和IL-5的水平;qRT-PCR检测肺组织miR-155的水平。结果 与CON组比较,OVA组小鼠的哮喘症状评分较高,IL-4、IL-5和miR-155表达水平上调（均P?<0.05）。与OVA组小鼠比较,随着槲皮素药物浓度的升高,槲皮素不同浓度组小鼠的哮喘症状评分下降,IL-4、IL-5和miR-155表达水平降低（均P?<0.05）。结论 槲皮素能改善支气管哮喘小鼠气道炎症,其机制可能与下调IL-4、IL-5和miR-155表达有关。     

槲皮素对阿尔茨海默症神经保护作用研究

阿尔茨海默症（Alzheimer’s disease,AD）临床特征为进行性认知能力下降和记忆力减退,目前临床上仍未发现有效的药物和治疗途径从根本上防治AD 的进展。槲皮素是一种黄酮类植物雌激素,可激动雌激素受体产生弱的雌激素活性,对神经系统具有保护作用。槲皮素具有较高的生物活性,且来源广泛,又无致畸,致癌和致死作用,逐渐受到了国内外学者广泛的关注。该文就槲皮素的生物活性、吸收、代谢,在AD 中的神经保护作用以及作用机制作一综述,以期为AD 相关治疗药物研究提供参考。