黄芩素对副溶血弧菌噬菌体裂解宿主的影响研究

论文以副溶血弧菌噬菌体为研究对象,通过研究黄芩素对副溶血弧菌噬菌体裂解宿主的影响来反映黄芩素的抗病毒效果,同时还研究了将黄芩素制备成环糊精包合物后对副溶血弧菌噬菌体裂解其宿主作用的影响。结果表明,黄芩素及其环糊精包合物均抑制了副溶血弧菌噬菌体对其宿主的裂解,且抑制作用均与它们的浓度与作用时间（一定时间范围内）成正相关;将黄芩素制备成环糊精包合物后有利于黄芩素对副溶血弧菌噬菌体裂解抑制作用的增强,在相同浓度下,黄芩素环糊精包合物对副溶血弧菌噬菌体作用60 min就能完全抑制了副溶血弧菌噬菌体对其宿主的裂解作用,而黄芩素则需要120 min。可见,利用副溶血弧菌噬菌体对其宿主的裂解作用来研究一些药效成分的抗病毒作用是一种简单、方便、成本较低的有效方法。     

汉黄芩素通过调控上皮间质转化抑制胃癌细胞的侵袭转移

目的:汉黄芩素是中药黄芩中的一种黄酮,具有体内外抗癌活性。然而,汉黄芩素对人胃癌细胞的作用尚不十分清楚。本研究拟探讨汉黄芩素对人胃癌细胞MGC-803侵袭转移能力的影响及其对上皮间质转化(Epithelial to Mesenchymal Transition,EMT)的作用机制。方法:采用MTT法测定汉黄芩素对人胃癌细胞MGC-803增殖能力的影响,通过划痕实验、Transwell试验检测汉黄芩素对人胃癌细胞MGC-803迁移、侵袭能力的影响。通过免疫印迹法和免疫荧光法分析汉黄芩素对EMT的影响。结果:20μM以上浓度的汉黄芩素能抑制人胃癌细胞MGC-803的增殖,不同浓度的汉黄芩素能抑制人胃癌细胞MGC-803的迁移和侵袭,且呈浓度依赖性。此外,汉黄芩素能抑制间质标记蛋白波形蛋白(Vimentin)和锌指蛋白E-盒结合同源异形盒-1(ZEB1)的表达,促进上皮标记蛋白E-钙黏蛋白(E-cadherin)的表达。结论:汉黄芩素能抑制胃癌细胞的侵袭和迁移,这一作用可能与其抑制EMT的发生有关。     

黄芩素磺化物的合成、抗氧化活性及其与DNA作用的研究

以黄芩素为先导化合物利用磺化反应首次合成水溶性黄酮——黄芩素-8-磺酸钠,采用IR、1HNMR和元素分析对黄芩素-8-磺酸钠结构进行了表征;同时,对磺化反应条件进行了优化。通过DPPH(1,1-二苯基-2-苦肼基自由基)法对黄芩素-8-磺酸钠清除自由基作用进行了研究;以溴化乙錠(EB)为荧光探针,研究了黄芩素-8-磺酸钠与CT-DNA的相互作用。实验结果表明:最佳的磺化反应条件为:黄芩素与浓硫酸比例1∶8(g/mL),100℃时反应12h。黄芩素-8-磺酸钠具有强抗氧化活性,与DNA结合作用显著。     

黄芩素抑制金黄色葡萄球菌生物被膜的形成

细菌生物被膜的形成是导致细菌耐药和引起持续性感染的主要原因之一。本文通过检测黄芩素对金黄色葡萄球菌26112菌株（Staphylococcus aureus 26112,SA26112）多糖细胞间黏附素（polysaccharide intercellular adhesion, PIA）的合成和胞外DNA（extracellular DNA,eDNA）释放量的影响,及其对icaA和cidA基因表达量的影响,探讨黄芩素对金黄色葡萄菌生物被膜形成的抑制作用及其机制。结果显示,黄芩素能抑制SA26112生物被膜的形成,其抑杀SA26112的最低抑菌浓度和最低杀菌浓度均为0.04 mg/mL。0.16 mg/mL黄芩素和256 μg/mL环丙沙星单独作用时,均不能杀死其成熟生物被膜内的SA26112细菌,而当二者联用时则可杀死成熟生物被膜内的细菌。黄芩素能显著抑制SA26112菌株PIA的合成、eDNA的释放量及icaA和cidA基因的相对表达量。其中,0.04 mg/mL黄芩素作用SA26112菌株24 h,与对照组相比,eDNA的释放量减少97%,icaA和cidA基因的相对表达量分别减少62%和41%。上述结果表明,黄芩素能抑制SA26112菌株生物被膜的形成,其作用机制可通过降低icaA和cidA的基因表达量,进而影响PIA的合成和eDNA的释放,来抑制金黄色葡萄球菌生物被膜的形成。     

黄芩苷通过下调FTH1诱导膀胱癌细胞铁死亡CSCD

铁死亡是由铁积累和随后的脂质过氧化引起的非凋亡调节细胞死亡。目前,铁死亡对癌症的治疗作用越来越受到关注。黄芩苷是黄芩中的一种活性成分,对各种癌症类型具有抗癌潜力。然而,黄芩素对膀胱癌的影响及其潜在的分子机制仍然很大程度上未知。     

黄芩苷抗炎作用机制的研究进展

黄芩苷(baicalin)是由黄芩(Scutellaria baicalensis Georgi)根部分离而来的黄酮类物质,为黄芩的主要活性成分。黄芩苷药理作用广泛,具有良好的抗炎效果,其主要机制包括调节肠道菌群、抑制核因子κB(NF-κB)核转位、增加相关microRNA的表达、抑制自噬、调节Treg/Th17平衡等。现综述黄芩苷抗炎症作用机制的最新研究进展,为其深入研究及在临床上的应用提供依据。     

HPLC同时测定龙胆泻肝制剂中黄芩苷、汉黄芩苷、黄芩素、汉黄芩素的含量

目的:建立同时测定龙胆泻肝制剂中黄芩苷、汉黄芩苷、黄芩素和汉黄芩素4种有效成分含量的HPLC分析方法.方法:色谱柱:Dikma Diamonsil C18柱(250 mm×4.6 mm,5μm);流动相:乙腈- 0.05％磷酸溶液,梯度洗脱;波长:278 nm.结果:黄芩苷、汉黄芩苷、黄芩素和汉黄芩素的线性范围分别为0.418～4.18μg(r=0.9999),0.2～2μg(r=0.9999),0.233～2.33 μg(r=0.9999),0.215～2.15(r=0.9998).2种制剂4种成分的平均回收率分别为98.10％ (RSD=0.59％),98.05％( RSD=1.37％),98.88％( RSD=1.44％),98.10％( RSD =0.59％)和98.40％ (RSD=0.46％),99.33％ (RSD=1.74％),99.09％( RSD=1.22％),98.82％(RSD=1.42％).结论:该方法快速、简便、准确、具有良好的重复性和回收率,可作为龙胆泻肝制剂中这4种成分的含量测定方法.     

非编码RNA调控流感病毒复制的作用及相关机制研究进展

流感病毒是一种重要人畜共患病,严重危害人类健康和畜牧业发展。A型流感病毒（Influenza A Virus, IAV）在宿主细胞内的复制受到多种因素的影响和调节,近年来的研究证明,非编码RNA(ncRNA),包括miRNA、LncRNA、CirRNA等,在流感病毒复制过程中起到重要的调控作用。ncRNA调控流感病毒复制有直接途径和间接途径两种,其中直接途径为直接作用于病毒的vRNA或mRNA,在转录或翻译水平影响病毒的复制。间接途径为作用于细胞内不同的信号通路,通过影响细胞因子合成、诱导宿主细胞凋亡、引起细胞自噬反应等途径,影响病毒的复制。通常情况下,由宿主编码的ncRNA能够抑制病毒的复制,而由病毒编码的ncRNA能够减弱宿主细胞的抗病毒反应,促进病毒复制。通过总结和梳理近年来关于ncRNA调控流感病毒复制的研究,我们发现ncRNA能够作为调控增强宿主细胞抗病毒免疫、下调病毒转录和翻译的工具,有望开发成为抗流感病毒靶向药物。后续的机制研究应不局限于某一种或几种ncRNA的作用,而应在ncRNA在宿主细胞内的分泌机制、调控的分子网络等方面进行深层次的探究。     

黄芩素对3T3-L1小鼠前脂肪细胞分化及对脂肪酸合成酶活性的影响

目的 研究黄芩素对3T3-L1小鼠前脂肪细胞分化及对脂肪酸合成酶活性的影响。方法 油红O染色法测定细胞分化速度;分光光度法测定脂肪酸合成酶活性。结果 黄芩素对3T3-L1小鼠前脂肪细胞向脂肪细胞分化以及对脂肪酸合成酶活性有抑制作用。结论 黄芩素通过阻断脂肪合成而抑制小鼠前脂肪细胞分化;黄芩素具有开发成减肥药物的潜力。     

Ferulaldehyde的体外抗流感作用研究

本研究对从蜘蛛香(Valeriana jatamansi Jones)和赤芍(Paeoniae Rubra Radix)中分离的一种苯丙素类化合物ferulaldehyde的抗甲型流感病毒的作用机制进行探索。通过加药时间点、免疫荧光实验、红细胞凝集法与神经氨酸酶活力检测等实验，发现化合物ferulaldehyde主要影响流感病毒的复制和释放环节，干扰病毒的生命周期从而发挥抗流感病毒活性。分子对接结果进一步确认流感病毒NP和NA蛋白很可能是它作用的靶点。同时，该化合物还能显著抑制由流感病毒引起的巨噬细胞炎症相关蛋白和趋化因子的表达。综上所述，化合物ferulaldehyde可能通过直接抑制流感病毒复制和释放的过程以及影响免疫细胞的功能从而发挥抗流感的作用。     

Pleiotropic Effects of Levofloxacin,Fluoroquinolone Antibiotics,against Influenza Virus-Induced Lung Injury

Reactive oxygen species (ROS) and nitric oxide (NO) are major pathogenic molecules produced during viral lung infections, including influenza. While fluoroquinolones are widely used as antimicrobial agents for treating a variety of bacterial infections, including secondary infections associated with the influenza virus, it has been reported that they also function as anti-oxidants against ROS and as a NO regulator. Therefore, we hypothesized that levofloxacin (LVFX), one of the most frequently used fluoroquinolone derivatives, may attenuate pulmonary injuries associated with influenza virus infections by inhibiting the production of ROS species such as hydroxyl radicals and neutrophil-derived NO that is produced during an influenza viral infection. The therapeutic impact of LVFX was examined in a PR8 (H1N1) influenza virus-induced lung injury mouse model. ESR spin-trapping experiments indicated that LVFX showed scavenging activity against neutrophil-derived hydroxyl radicals. LVFX markedly improved the survival rate of mice that were infected with the influenza virus in a dose-dependent manner. In addition, the LVFX treatment resulted in a dose-dependent decrease in the level of 8-hydroxy-2’-deoxyguanosine (a marker of oxidative stress) and nitrotyrosine (a nitrative marker) in the lungs of virus-infected mice, and the nitrite/nitrate ratio (NO metabolites) and IFN-γ in BALF. These results indicate that LVFX may be of substantial benefit in the treatment of various acute inflammatory disorders such as influenza virus-induced pneumonia, by inhibiting inflammatory cell responses and suppressing the overproduction of NO in the lungs.     

Galectin-1 binds to influenza virus and ameliorates influenza virus pathogenesis

Innate immune response is important for viral clearance during influenza virus infection. Galectin-1, which belongs to S-type lectins, contains a conserved carbohydrate recognition domain that recognizes galactose-containing oligosaccharides. Since the envelope proteins of influenza virus are highly glycosylated, we studied the role of galectin-1 in influenza virus infection in vitro and in mice. We found that galectin-1 was upregulated in the lungs of mice during influenza virus infection. There was a positive correlation between galectin-1 levels and viral loads during the acute phase of viral infection. Cells treated with recombinant human galectin-1 generated lower viral yields after influenza virus infection. Galectin-1 could directly bind to the envelope glycoproteins of influenza A/WSN/33 virus and inhibit its hemagglutination activity and infectivity. It also bound to different subtypes of influenza A virus with micromolar dissociation constant (K(d)) values and protected cells against influenza virus-induced cell death. We used nanoparticle, surface plasmon resonance analysis and transmission electron microscopy to further demonstrate the direct binding of galectin-1 to influenza virus. More importantly, we show for the first time that intranasal treatment of galectin-1 could enhance survival of mice against lethal challenge with influenza virus by reducing viral load, inflammation, and apoptosis in the lung. Furthermore, galectin-1 knockout mice were more susceptible to influenza virus infection than wild-type mice. Collectively, our results indicate that galectin-1 has anti-influenza virus activity by binding to viral surface and inhibiting its infectivity. Thus, galectin-1 may be further explored as a novel therapeutic agent for influenza.     

黄芩汤药效物质基础及其治疗胃肠道疾病研究进展

黄芩汤是《伤寒论》中治疗下痢的经典方剂,由黄芩、芍药、甘草(炙)和大枣四味中药煎煮而成,用于治疗痢疾、腹泻等胃肠道疾病已有近1800年,中药治疗胃肠道疾病相较于西药更安全。本文结合国内外相关文献,对近几年来黄芩汤药效物质基础研究进行概括总结,并对其治疗溃疡性结肠炎和减轻化疗药物胃肠道毒性机制的最新研究进行了综述,结合胃肠道疾病的发病机制以及黄芩汤减毒机制的研究方法对现有研究过程中存在的不足进行了评述,并对中药疗效研究展开设想,提出以组学作为研究手段,配合中药复方整体作用模式的组分-疗效研究思路,以期为黄芩汤治疗胃肠道疾病的研究提供参考。     

Treatment with the reactive oxygen species scavenger EUK-207 reduces lung damage and increases survival during 1918 influenza virus infection in mice

The 1918 influenza pandemic caused over 40 million deaths worldwide, with 675,000 deaths in the United States alone. Studies in several experimental animal models showed that 1918 influenza virus infection resulted in severe lung pathology associated with dysregulated immune and cell death responses. To determine if reactive oxygen species produced by host inflammatory responses play a central role in promoting severity of lung pathology, we treated 1918 influenza virus-infected mice with the catalytic catalase/superoxide dismutase mimetic, salen–manganese complex EUK-207 beginning 3 days postinfection. Postexposure treatment of mice infected with a lethal dose of the 1918 influenza virus with EUK-207 resulted in significantly increased survival and reduced lung pathology without a reduction in viral titers. In vitro studies also showed that EUK-207 treatment did not affect 1918 influenza viral replication. Immunohistochemical analysis showed a reduction in the detection of the apoptosis marker cleaved caspase-3 and the oxidative stress marker 8-oxo-2′-deoxyguanosine in lungs of EUK-207-treated animals compared to vehicle controls. High-throughput sequencing and RNA expression microarray analysis revealed that treatment resulted in decreased expression of inflammatory response genes and increased lung metabolic and repair responses. These results directly demonstrate that 1918 influenza virus infection leads to an immunopathogenic immune response with excessive inflammatory and cell death responses that can be limited by treatment with the catalytic antioxidant EUK-207.     

Characterization of flavonoids in the traditional Chinese herbal medicine-Huangqin by liquid chromatography coupled with electrospray ionization mass spectrometry

The root of Scutellaria baicalensis, called Huangqin in Chinese, is one of the most commonly used traditional Chinese medicines for the treatment of hepatitis, tumors, diarrhea, and inflammatory diseases. The major chemical constituents of Huangqin are flavonoids. In the present paper, HPLC-DAD-ESI-MS(n) was used to analyze flavonoids in the roots of S. baicalensis. A total of 26 flavonoids were identified or tentatively characterized, including 5 C-glycosides, 12 O-glycosides, and 9 free aglycones. Two C-glycosides, apigenin-6-C-glucyl-8-C-arabinoside and chrysin-6,8-di-C-glucoside, together with some O-glycosides, are reported from S. baicalensis for the first time. This method is simple, reliable and sensitive, and could be used for the quality control of Huangqin and its related preparations.     

Inhibition of mouse liver sialidase by plant flavonoids

Flavonoids (103 species) were tested for inhibitory activity against mouse liver sialidase using sodium p-nitrophenyl-N-acetyl-alpha-D-neuraminate (PNP-NeuAc) as substrate. Isoscutellarein-8-O-glucuronide from the leaf of Scutellaria baicalensis showed most potent activity (IC50, 40 microM), and this flavone appeared to be a non-competitive inhibitor of the enzyme. This flavone inhibited the lysosomal solubilized sialidase against PNP-NeuAc and sialyllactose effectively, but not microsomal enzyme against gangliosides and colominic acid, whereas, negligible or weak inhibitory activities were observed for influenza virus sialidase, beta-galactosidase, alpha-mannosidase, and alpha-glucosidase tested. These results indicate that this flavone may be useful to elucidate the function of the lysosomal solubilized sialidase.     

IL-15 participates in the respiratory innate immune response to influenza virus infection

Following influenza infection, natural killer (NK) cells function as interim effectors by suppressing viral replication until CD8 T cells are activated, proliferate, and are mobilized within the respiratory tract. Thus, NK cells are an important first line of defense against influenza virus. Here, in a murine model of influenza, we show that virally-induced IL-15 facilitates the trafficking of NK cells into the lung airways. Blocking IL-15 delays NK cell entry to the site of infection and results in a disregulated control of early viral replication. By the same principle, viral control by NK cells can be therapeutically enhanced via intranasal administration of exogenous IL-15 in the early days post influenza infection. In addition to controlling early viral replication, this IL-15-induced mobilization of NK cells to the lung airways has important downstream consequences on adaptive responses. Primarily, depletion of responding NK1.1+ NK cells is associated with reduced immigration of influenza-specific CD8 T cells to the site of infection. Together this work suggests that local deposits of IL-15 in the lung airways regulate the coordinated innate and adaptive immune responses to influenza infection and may represent an important point of immune intervention.     

Interleukin-12p40 modulates human metapneumovirus-induced pulmonary disease in an acute mouse model of infection

The mechanisms that regulate the host immune response induced by human metapneumovirus (hMPV), a newly-recognized member of the Paramyxoviridae family, are largely unknown. Cytokines play an important role in modulating inflammatory responses during viral infections. IL-12p40, a known important mediator in limiting lung inflammation, is induced by hMPV and its production is sustained after the resolution phase of infection suggesting that this cytokine plays a role in the immune response against hMPV. In this work, we demonstrated that in mice deficient in IL-12p40, hMPV infection induced an exacerbated pulmonary inflammatory response and mucus production, altered cytokine response, and decreased lung function. However, hMPV infection in these mice does not have an effect on viral replication. These results identify an important regulatory role of IL-12p40 in hMPV infection.     

Pulmonary immune cells and inflammatory cytokine dysregulation are associated with mortality of IL-1R1-/-mice infected with influenza virus (H1 N1)

Respirovirus infection can cause viral pneumonia and acute lung injury (ALI).The interleukin-1 (IL-1) family consists of proinflammatory cytokines that play essential roles in regulating immune and inflammatory responses in vivo.IL-1 signaling is associated with protection against respiratory influenza virus infection by mediation of the pulmonary anti-viral immune response and inflammation.We analyzed the infiltration lung immune leukocytes and cytokines that contribute to inflammatory lung pathology and mortality of fatal H1N1 virus-infected IL-1 receptor 1 (IL-1R1) deficient mice.Results showed that early innate immune cells and cytokine/chemokine dysregulation were observed with significantly decreased neutrophil infiltration and IL-6,TNF-α,G-CSF,KC,and MIP-2 cytokine levels in the bronchoalveolar lavage fluid of infected IL-1R1-/-mice in comparison with that of wild type infected mice.The adaptive immune response against the H1N1 virus in IL-1R1-/-mice was impaired with downregulated anti-viral Th1 cell,CD8+ cell,and antibody functions,which contributes to attenuated viral clearance.Histological analysis revealed reduced lung inflammation during early infection but severe lung pathology in late infection in IL-1R1-/-mice compared with that in WT infected mice.Moreover,the infected IL-1R1-/-mice showed markedly reduced neutrophil generation in bone marrow and neutrophil recruitment to the inflamed lung.Together,these results suggest that IL-1 signaling is associated with pulmonary anti-influenza immune response and inflammatory lung injury,particularly via the influence on neutrophil mobilization and inflammatory cytokine/chemokine production.     

Protective Effects of Specific Immunity to Viral Neuraminidase on Influenza Virus Infection of Mice

Antibody specific for viral neuraminidase can be demonstrated in mice following (i) pulmonary infection with influenza virus, (ii) immunization with ultraviolet-in-activated influenza virus, (iii) immunization with isolated neuraminidase of influenza A(2) virus, and (iv) passive immunization with sera of rabbits immunized with isolated A(2) neuraminidase. Neuraminidase antibody produced by any of these methods exerts a profound inhibiting effect on virus replication in the lungs of mice challenged with strains of virus having homologous neuraminidase protein, even in the absence of hemagglutinating inhibiting antibody to the challenge virus, and results in markedly decreased pulmonary virus titers and diminished lung lesions. These observations suggest that antineuraminidase immunity may play a significant role in the protection against influenza virus challenge observed in mice after infection or artificial immunization.