Sesquiterpene Glucosides from Anti-leukotriene B4 Release Fraction of Taraxacum Officinale

Abstract

Chemical examination of the MeOH extract of the root of Taraxacum officinale, which exhibited inhibitory activity on the formation of leukotriene B₄ from activated human neutrophils, has resulted in the isolation of 14-O-β-D-glucosyl-11,13-dihydro-taraxinic acid (1) and 14-O-β-D-glucosyl-taraxinic acid (2). The absolute stereostructure of 1 has been established by X-ray chrystallographic examination.     

Hepatoprotective effect of Taraxacum officinale leaf extract on sodium dichromate‐induced liver injury in rats

Taraxacum officinale (L.) Weber, commonly known as Dandelion, has been widely used as a folkloric medicine for the treatment of liver and kidney disorders and some women diseases such as breast and uterus cancers. The main objective of the present study was to assess the efficiency of T. officinale leaf extract (TOE) in treating sodium dichromate hazards; it is a major environmental pollutant known for its wide toxic manifestations witch induced liver injury. TOE at a dose of 500 mg/kg b.w was orally administered once per day for 30 days consecutively, followed by 10 mg/kg b.w sodium dichromate was injected (intraperitoneal) for 10 days. Our results using Wistar rats showed that sodium dichromate significantly increased serum biochemical parameters. In the liver, it was found to induce an oxidative stress, evidenced from increase in lipid peroxidation and changes in antioxidative activities. In addition, histopathological observation revealed that sodium dichromate causes acute liver damage, necrosis of hepatocytes, as well as DNA fragmentation. Interestingly, animals that were pretreated with TOE, prior to sodium dichromate administration, showed a significant hepatoprotection, revealed by a significant reduction of sodium dichromate‐induced oxidative damage for all tested markers. These finding powerfully supports that TOE was effective in the protection against sodium dichromate‐induced hepatotoxicity and genotoxicity and, therefore, suggest a potential therapeutic use of this plant as an alternative medicine for patients with acute liver diseases. © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 339–349, 2016.     

Antioxidant properties of Taraxacum officinale fruit extract are involved in the protective effect against cellular death induced by sodium nitroprusside in brain of rats

Context: Taraxacum officinale Weber (Asteraceae), known as dandelion, is used for medicinal purposes due to its choleretic, diuretic, antitumor, antioxidant, antiinflammatory, and hepatoprotective properties.

Objective: We sought to investigate the protective activity of T. officinale fruit extract against sodium nitroprusside (SNP)-induced decreased cellular viability and increased lipid peroxidation in the cortex, hippocampus, and striatum of rats in vitro. To explain the mechanism of the extract’s antioxidant activity, its putative scavenger activities against NO^˙, DPPH^˙, OH^˙, and H₂O₂ were determined.

Methods: Slices of cortex, hippocampus, and striatum were treated with 50 μM SNP and T. officinale fruit ethanolic extract (1–20 µg/mL) to determine cellular viability by MTT reduction assay. Lipid peroxidation was measure in cortical, hippocampal and striatal slices incubates with SNP (5 µM) and T. officinale fruit extract (1–20 µg/mL). We also determined the scavenger activities of T. officinale fruit extract against NO^˙, DPPH^˙, OH^˙, and H₂O₂, as well as its iron chelating capacity.

Results: The extract (1, 5, 10, and 20 μg/mL) protected against SNP-induced decreases in cellular viability and increases in lipid peroxidation in the cortex, hippocampus, and striatum of rats. The extract had scavenger activity against DPPH^˙ and NO^˙ at low concentrations and was able to protect against H₂O₂ and Fe²⁺-induced deoxyribose oxidation.

Conclusion: T. officinale fruit extract has antioxidant activity and protects brain slices against SNP-induced cellular death. Possible mechanisms of action include its scavenger activities against reactive oxygen species (ROS) and reactive nitrogen species (RNS), which are attributed to the presence of phenolic compounds in the extract.     

Dependence of Dandelion (Taraxacum officinale Wigg.) Seed Reproduction Indices on Intensity of Motor Traffic Pollution

Dandelion (Taraxacum officinale Wigg.) seed reproduction indices such as the total number of seeds, the number of normally developed seeds and underdeveloped seeds per anthodium, and seed weight are suggested to assess the level of environmental pollution (bioindication). However, the non-monotonic dose-response dependences (hormesis and paradoxical effects) of these indices are insufficiently explored upon exposure to pollution. We studied the dependence of some T. officinale seed reproduction indices on intensity of motor traffic pollution in wide range of values over 2 years of observation. In 2010, the increase in traffic intensity induced a monotonic increase in the total seed number and the number of normally developed seeds. Besides, motor traffic pollution decreased the number of undeveloped seeds and seed weight in comparison with the control. In 2011, for all studied T. officinale indices except seed weight, complicated non-monotonic dependences on traffic intensity were found that could be attributed to paradoxical effects. It is hypothesised that the significant differences in the studied dependencies in 2010–2011 were caused by changes in weather conditions because traffic intensity did not differ significantly between the two observation years.     

蒲公英质量标准提升及不同产地药用蒲公英质量评价

目的:提升蒲公英药材质量标准,并评价不同产地药用蒲公英药材的质量.方法:在2020年版《中国药典》(一部)"蒲公英"项下规定的基础上,增加水溶性浸出物(热浸法)、醇溶性浸出物(热浸法)、总黄酮、绿原酸、咖啡酸、菊苣酸和异绿原酸A的含量测定方法,同时以8个产地42批药用蒲公英药材为对象建立高效液相色谱(HPLC)指纹图谱...     

Japonicins A and B from the flowers of Inula japonica

Two new flavonols japonicins, A (1) and B (2), along with nine known flavonoids were isolated from an antidepressant fraction, which was separated from the 70% alcohol extract of the flowers of Inula japonica Thumb. The structures of compounds 1 and 2 were determined as 3,3′,4′,5,9,10-hexahydroxy-12-methylchroman[2,3-h]flavone and 8-(1-(3,4-dihydroxyphenyl)ethyl)-3,3′,4′,5,7-pentahydroxyflavone by the analyses of physical constants and spectral data. The special flavonoid structure having the substituent 1-phenylethyl at C-8 position was discovered for the first time.     

Japonicins A and B from the flowers of Inula japonica

Two new flavonols japonicins, A (1) and B (2), along with nine known flavonoids were isolated from an antidepressant fraction, which was separated from the 70% alcohol extract of the flowers of Inula japonica Thumb. The structures of compounds 1 and 2 were determined as 3,3',4',5,9,10-hexahydroxy-12-methylchroman[2,3-h]flavone and 8-(1-(3,4-dihydroxyphenyl)ethyl)-3,3',4',5,7-pentahydroxyflavone by the analyses of physical constants and spectral data. The special flavonoid structure having the substituent 1-phenylethyl at C-8 position was discovered for the first time.     

维生素B4片溶出度测定方法研究

目的对维生素B4片的溶出度测定方法进行研究。方法采用紫外分光光度法测定维生素B4片的溶出度，测定波长为（262±1）nm。结果维生素B4质量浓度在4～16μg／mL范围内与吸收度线性关系良好，r=0．9997（n=6），平均回收率为99．59％，RSD=0．8％（n=9）。结论该方法灵敏，结果准确可靠，重现性好，可用于维生素B4片的溶出度测定。     

Development and characterization of a replicon-based phenotypic assay for assessing HCV NS4B from clinical isolates

The hepatitis C virus (HCV) NS4B inhibitors have shown potent inhibition of HCV replication in vitro. To assess the effect of viral diversity on the susceptibility to NS4B inhibitors, genotype (GT)-specific GT1a and GT1b replicon shuttle vectors were designed and created for cloning HCV NS4B genes from clinical isolates. For the GT1b NS4B shuttle vector, the S2204I adaptive mutation was introduced in NS5A to improve replication due to the replacement of the K1846T adaptive mutation in NS4B with NS4B from the clinical isolates. In addition to the adaptive mutations, a newly identified Huh-7 cell line, Huh-7-1C, which is highly permissive for both GT1a and GT1b replication, was used to further enhance the replication levels. HCV NS4B gene from clinical isolates was amplified and inserted into the corresponding GT1a and GT1b modified lab strain chimeric replicons. GT1a and GT1b chimeric replicons expressing diverse NS4B genes from corresponding subtypes of clinical isolates replicated at highly efficient levels for phenotypic analysis. Due to natural variation in their amino acid residues in NS4B, these isolates displayed varying drug susceptibilities to an NS4B inhibitor. In mixed populations with wild-type, the sensitivity of resistance detection of NS4B resistant mutants H94R and V105M was between 20% and 80%. The chimeric shuttle vectors can be used to characterize the activity of antiviral drugs targeting NS4B from diverse natural clinical isolates and aid in the development of novel compounds against HCV NS4B.     

皱瘤海鞘提取物体外抗乙肝病毒有效部位的筛选

目的:筛选皱瘤海鞘体外抗乙肝有效部位.方法:应用酶联免疫技术(ELISA)测定血清中表面抗原(HBsAg)、e抗原(HBeAg)的OD值,评价皱瘤海鞘不同部位抗乙肝病毒(HBV)的活性.结果:水溶性提取部位显示明显的抗HBsAg、HBeAg作用,而其他部位作用不明显.结论:皱瘤海鞘提取物在体外具有抗乙肝病毒的作用,有效部位为水溶性成分.     

HPLC法测定维生素B4片的有关物质

目的：建立高效液相色谱法测定维生素B4片的有关物质。方法采用Waters SunFireTM C18柱（250mm×4.6mm,5μm）,流动相为甲醇-0.05mol· L-1磷酸二氢钾溶液-三乙胺（10∶90∶0.25）,流速0.8mL· min -1,检测波长261nm。结果主峰与各降解产物峰的分离良好,方法的精密度良好。结论本方法简便、准确、灵敏度高,可用于维生素B4片的有关物质检查。     

B7-H4在胃腺癌中的表达及临床意义

目的研究B7-H4蛋白在胃腺癌中的表达及临床意义。方法应用S-P免疫组化法检测B7-H4蛋白在20例正常胃黏膜、50例胃腺癌中的表达情况。结果 B7-H4在胃癌中的阳性表达率（82%）高于正常胃黏膜组（10%）,差异有显著意义（P〈0.05）。B7-H4在胃腺癌中的表达与年龄、性别无关（P〉0.05）,而与组织学分级、浸润深度及淋巴结转移有关（P〈0.05）。结论 B7-H4在胃腺癌中表达上调,可能与胃腺癌的转移和预后相关。     

磷酸二酯酶4B在博来霉素诱导的肺纤维化小鼠肺组织中的表达与作用

目的观察博来霉素诱导的小鼠肺纤维化过程中磷酸二酯酶4B(PDE4B)mRNA和蛋白表达随时间的变化,初步探究PDE4B在小鼠肺纤维化过程中的作用。方法采用气道滴入博来霉素2.5 mg·kg-1制备肺纤维化模型,在造模后第3,7,14,21和28天进行支气管肺泡灌洗并留取肺组织。应用细胞形态学方法计数支气管肺泡灌洗液(BALF)中白细胞总数和分类;ELISA法测定BALF中巨噬细胞炎症蛋白2(MIP2)、白细胞介素6(IL-6)、IL-1β和转化生长因子β1(TGF-β1)含量;胶原试剂盒测定法测定肺组织胶原含量;髓过氧化物酶(MPO)活性测定试剂盒测定组织匀浆液中MPO活性;实时荧光定量PCR方法检测小鼠肺组织中PDE4B mRNA表达;免疫组织化学法检测PDE4B的分布。结果博来霉素气道滴入诱导的肺纤维化随时间持续加重,第28天最明显,可见肺组织明显实质化。BALF中白细胞总数、IL-1β和IL-6在造模后第3天达峰值,分别为正常对照组的22.0,2.0和2.8倍;MPO和TGF-β1在第7天达峰值,分别为正常对照组的1.9和5.5倍;胶原含量、MIP-2和PDE4B mRNA表达从造模后呈持续增长趋势,分别为正常对照组的1.6,2.7和2.6倍。免疫组织化学法检测结果表明,PDE4B分布于炎症细胞和纤维化的肺组织。结论PDE4B在肺纤维化中发挥重要作用,可能是一个特异性的药物作用靶点。     

UPLC-MS/MS测定大鼠血浆中柴胡皂苷B2、B4的含量及药动学研究

目的 建立UPLC-MS/MS测定大鼠血浆中柴胡皂苷B2、B4,并对柴胡皂苷B2、B4静脉给药后的药动学进行研究。方法 以柴胡皂苷F为内标,采用UPLC BEH C₁₈（2.1 mm×50 mm,1.7 μm）柱,柱温为40℃。流动相为乙腈-0.1%甲酸水溶液,梯度洗脱,流速为0.4 mL·min^-1,洗脱时间为4 min,使用氮气作为去溶剂化气体（800 L·h^-1）和锥形气体（50 L·h^-1）。MRM模式对柴胡皂苷B2 m/z 825.4→617.5、柴胡皂苷B4 m/z 957.6→649.6和柴胡皂苷F（内标）m/z 973.7→119.0进行定量分析。大鼠血浆用乙腈沉淀法去除蛋白。结果 在5~5 000 ng·mL^-1内,大鼠血浆中柴胡皂苷B2、B4线性良好（r>0.995）,定量下限为5 ng·mL^-1。柴胡皂苷B2日内精密度RSD<12%,日间精密度RSD<15%。柴胡皂苷B4日内精密度RSD<14%,日间精密度RSD<15%。柴胡皂苷B2、B4的准确度范围为89.3%~110.2%。结论 该分析方法灵敏、快速、选择性良好,并成功应用于柴胡皂苷B2、B4静脉给药后的大鼠药动学研究。     

Stimulation by surangin B of endogenous amino acid release from synaptosomes.

The effect of surangin B, an insecticidal natural product coumarin, on presynaptic release of endogenous amino acids was investigated using a purified synaptosomal fraction isolated from mouse brain. Surangin B stimulated the release of glutamic acid (GLU), gamma-aminobutyric acid (GABA), serine, alanine and the aminosulfonic acid taurine from synaptosomes at micromolar concentrations. In all cases, these responses were reduced by removing calcium from the saline and surangin B-evoked release of GLU, GABA, aspartic acid (ASP) and alanine was significantly inhibited by the sodium channel blocker tetrodotoxin. Rotenone (a complex I inhibitor) and carbonyl cyanide chlorophenylhydrazone (CCCP; an uncoupler), were more potent releasers of amino acids from synaptosomes than surangin B, however, carboxin (a complex II-selective inhibitor), was extremely weak to ineffective in this regard. The stimulatory effect of surangin B and complex III-selective inhibitors on release of GLU, GABA, ASP and alanine by synaptosomes was significantly reduced by N,N,N',N'-tetramethyl-p-phenylenediamine, suggesting that blockade of complex III in intraterminal mitochondria is an important effect of this coumarin. Our results demonstrate that surangin B, in common with CCCP and inhibitors of complex I and III, cause release of both neurotransmitter and non-neurotransmitter amino acids from nerve endings in vitro. However, in contrast to most classical agents which interfere selectively with mitochondrial function, the release of endogenous amino acids from synaptosomes by surangin B also involves a moderate extracellular calcium ion-dependent component and relies partially on sodium ion entry into the nerve ending.     

砒石对哮喘小鼠肺组织白三烯含量的影响

目的探讨砒石对哮喘小鼠的治疗作用及对肺组织LTB4、LTC4水平的影响。方法建立小鼠卵蛋白哮喘模型,灌胃给予砒石等药,对肺泡灌洗液进行白细胞分类计数,肺组织切片HE染色观察病理变化,用ELISA法检测肺组织匀浆LTB4、LTC4含量。结果哮喘组小鼠肺组织匀浆中LTB4、LTC4含量较生理盐水对照组升高。砒石1.25mg/kg能降低哮喘小鼠肺组织LTB4的含量;砒石0.625mg/kg可降低哮喘小鼠肺组织中LTC4水平至正常。砒石不能影响哮喘小鼠肺泡灌洗液中白细胞分类百分比。结论肺组织中LTB4、LTC4水平的增高可能在哮喘的发病中起作用。砒石能减轻哮喘小鼠肺的病理损害,降低哮喘小鼠肺组织LTB4、LTC4水平,从而表现出抗哮喘的活性。     

B7-H4介导肿瘤免疫逃逸机制及临床研究进展

协同刺激分子B7-H4是B7家族中的新成员,能通过抑制T细胞增殖、减少细胞因子产生和减慢细胞周期进程而负性调控T细胞免疫应答。研究表明,B7-H4在多种肿瘤细胞及组织中均呈高表达,与肿瘤免疫逃逸关系密切,在肿瘤的发生、发展和转归中发挥重要作用。研究B7-H4在肿瘤中的表达和意义,有助于阐明肿瘤免疫逃逸机制,也为肿瘤的免疫治疗提供新的靶点和策略。     

P15~(INK4B)和P16~(INK4A)基因在鼻咽癌组织中异常甲基化

目的通过检测P15INK4B和P16INK4A基因启动子区甲基化情况,分析其与鼻咽癌发生发展及临床病理特征关系,探讨其可能在鼻咽癌临床早期分子生物学诊断和治疗中的作用。方法运用甲基化特异性聚合酶链反应(PCR)对54例鼻咽癌组织和20例正常鼻咽上皮组织的P15INK4B和P16INK4A基因启动子区甲基化状态进行检测。结果鼻咽癌组织中P15INK4B和P16INK4A基因启动子区甲基化阳性率分别为22%(12/54)和46%(25/54),二者总检出率为48%(26/54),26例甲基化的癌组织同时出现二者甲基化为11例;而在正常鼻咽上皮组织中未检测到P15INK4B和P16INK4A基因启动子区甲基化。结论P15INK4B和P16INK4A基因启动子区甲基化与患者临床病理特征无明显相关关系,为鼻咽癌早期事件,有望成为早期分子生物学诊断的标志物,将来还可能作为去甲基化基因治疗的靶点。二者在鼻咽癌发生发展中可能存在协同作用。     

虎杖苷通过TLR4/NF-κB信号通路调控糖尿病肾病大鼠肾脏炎症作用的研究

目的：研究虎杖苷通过TLR4/NF-κB信号通路调控糖尿病肾病大鼠肾脏炎症作用的影响。方法：通过尾静脉注射链脲佐菌素,高脂饲料喂养建立糖尿病肾病大鼠模型。将成模的大鼠随机分为模型组、缬沙坦组（20 mg·kg^-1）、虎杖苷组（75 mg·kg^-1）、虎杖苷组（150 mg·kg^-1）,每组10只,日常进行高脂饮食喂养,连续灌胃给药90 d,每日1次。于第90天采集尿液,测量尿量及终点法测24 h尿白蛋白（UP）含量。通过HE染色观察大鼠肾脏组织的病理学变化。采用ELISA法检测肾组织中TGF-β1、FN纤维化指标表达及肾脏组织中炎症因子肿瘤坏死因子（TNF-α）、白介素-1β（IL-1β）、白介素-6（IL-6）的含量。Western blot法检测肾组织中Toll样受体4（TLR4）、髓样分化因子（Myd88）、核转录因子kappa B（NF-κB）的表达。结果：与模型组相比,虎杖苷组大鼠Scr、BUN、UP含量显著降低（P<0.05）。TGF-β1、FN纤维化指标明及炎症因子TNF-α、IL-1β、IL-6含量显减少（P<0.05）,TLR4、Myd88、NF-κB蛋白表达显著降低（P<0.05）。结论：虎杖苷对糖尿病肾病所引起的肾脏炎症有一定的保护作用,其作用机制可能与调节TLR4/NF-κB信号通路,降低肾脏组织的炎症因子含量,而起到抗炎的保护作用有关。     

白三烯B4在儿童幽门螺杆菌相关性胃炎发生中的作用

目的探讨白三烯B4(LTB4)在儿童幽门螺杆菌(H.pylori)相关性胃炎发生中的作用。方法经胃镜确诊的胃炎45例患儿中,H.pylori阳性23例,H.pylori阴性22例。用ELISA法同时检测患儿血清及胃液中LTB4水平。结果 H.pylori阳性患儿血清LTB4为(2.063±1.016)ng/L,明显高于H.pylori阴性患儿的(0.441±0.894)ng/L(P<0.01);H.pylori阳性组胃液中LTB4浓度亦高于H.pylori阴性组(P<0.05)。结论 LTB4可能参与并促进H.pylori相关性胃炎发生、发展。