异丹叶大黄素在体外对Cu2+介导的人低密度脂蛋白过氧化的抑制作用

目的研究异丹叶大黄素(Iso)对Cu2 介导的人低密度脂蛋白(LDL)过氧化及氧化LDL(ox-LDL)对小鼠巨噬细胞毒性的抑制作用.方法用序贯超离心法分离血脂正常的供血者血清LDL,分离的LDL 1 mg·mL-1 磷酸缓冲液(pH 7.4), 与10 μmol·L-1 CuSO4于37℃水浴温育10 h 以引起LDL过氧化,给药组预先加入不同浓度Iso,对照组加等量生理盐水,测定丙二醛(MDA)的生成量、维生素E的耗竭以及LDL电泳迁移率.另外测定用ox-LDL处理小鼠腹腔巨噬细胞线粒体的膜电位、吞噬刚果红及释放NO的量.结果 1-100 μmol·L-1 Iso 剂量依赖性地抑制Cu2 引起的人LDL氧化时MDA的生成量、维生素E的耗竭及电泳迁移率的升高.10 μmol·L-1 Iso能防止0.1 mg·mL-1 ox-LDL与小鼠腹腔巨噬细胞温育4 h 后线粒体膜电位的损伤、吞噬刚果红功能以及NO释放量的降低.结论 Iso在体外对Cu2 介导的LDL过氧化以及ox-LDL对小鼠巨噬细胞的毒性有保护作用.     

异丹叶大黄素对脂多糖诱导的小鼠急性肺损伤的影响

目的 探究异丹叶大黄素(ISO)对脂多糖(LPS)诱导的小鼠急性肺损伤(ALI)的保护作用及潜在机制。方法 体外培养RAW264.7细胞,采用不同浓度ISO处理细胞,CCK-8法检测细胞活力。使用200 ng/ml LPS诱导RAW264.7细胞,以ISO、自噬抑制剂3-甲基腺嘌呤(3-MA)进行干预,Western blot检测各组细胞中炎症介质白细胞介素(IL)-1β、IL-6、肿瘤坏死因子-α(TNF-α)、P65、磷酸化P65(p-P65)、IκB、磷酸化IκB(p-IκB)、诱生型一氧化氮合酶(iNOS)、环氧合酶2(COX-2)、高迁移率组蛋白B1(HMGB1)以及自噬相关蛋白LC3Ⅱ/Ⅰ、Beclin1、P62的表达,DCFH-DA探针检测各组细胞内活性氧(ROS)的变化。采用腹腔注射LPS(15 mg/kg)方法构建小鼠ALI模型,HE染色观察各组肺组织形态的病理变化,Western blot检测各组肺组织中炎症介质和自噬相关蛋白的表达,流式细胞术检测支气管肺泡灌洗液(BALF)中ROS的含量。结果 ISO可以抑制LPS诱导的RAW264.7细胞炎症因子IL-1β、IL...     

Biomimetic synthesis of active isorhapontigenin dimers

Synthetic isorhapontigenin was treated with several kinds of inorganic reagents and peroxidase so as to prepare active stilbene dimers. Among them, silver acetate in methanol gave two new isorhapontigenin dimers 4 and 5, together with four known natural stilbene dimers 2, 3, 6, and 7. Their structures and relative configurations were determined on the basis of spectral analysis, and their possible formation mechanisms were discussed, respectively. Compounds 2, 6, and 7 were artificially synthesized for the first time. All the products were evaluated for anti-inflammatory activities.     

Isorhapontigenin and resveratrol suppress oxLDL-induced proliferation and activation of ERK1/2 mitogen-activated protein kinases of bovine aortic smooth muscle cells

The objective of our study was to compare the inhibitory effect of isorhapontigenin (ISO) and resveratrol, two natural antioxidants, on oxidized low-density lipoprotein (oxLDL)-induced proliferation of bovine aortic smooth muscle cells (BASMCs) and its relation to reactive oxygen species (ROS) generation and extracellular signal-regulated kinase 1/2 activation. The results showed that stimulation of oxLDL (50-150 microg/mL) for 48 hr induced a dose-dependent increase in cell number and incorporation of [3H]thymidine into DNA of BASMCs. Western blot analysis demonstrated that oxLDL (150 microg/mL) stimulated an evident phosphorylation of p42/44 MAP kinases in BASMCs. Incubation of BASMCs with oxLDL induced significant increase in ROS detected by using an oxidant-sensitive fluorescent probe of 2',7'-dichlorofluorescin diacetate. The level of H2O2 in the medium of cultured BASMCs also increased markedly. Preincubation of BASMCs with ISO and resveratrol significantly inhibited oxLDL-induced cell proliferation and incorporation of [3H]thymidine, and the phosphorylation of p42/44 MAP kinases in BASMCs as well. Furthermore, preincubation of BASMCs with ISO and resveratrol attenuated oxLDL-induced increases in ROS and H2O2 levels. The results suggested that oxLDL-induced acute formation of ROS and subsequent activation of redox-sensitive extracellular signal-regulated kinase 1/2 MAPK pathways, which might be important for mitogenic signaling of oxLDL in vascular smooth muscle cells. The inhibitory effect of ISO and resveratrol on oxLDL-induced mitogenesis of BASMCs might be taken through blocking the generation of ROS and activation of the ERKs pathway.     

HPLC-DAD同时测定清感穿心莲片中3种成分的含量

目的 建立清感穿心莲片中穿心莲内酯、脱水穿心莲内酯和异丹叶大黄素3种成分的HPLC含量测定方法,为清感穿心莲片的质量控制提供参考。方法 采用HPLC-DAD法,Agilent Extend C₁₈色谱柱（4.6 mm×250 mm,5 μm）,以乙腈（A）-水（B）为流动相进行梯度洗脱,检测波长225 nm （穿心莲内酯）,254 nm （脱水穿心莲内酯）,323 nm （异丹叶大黄素）,柱温35℃,流速0.8 mL·min^-1。结果 穿心莲内酯、脱水穿心莲内酯和异丹叶大黄素分别在8.395~335.790 μg·mL^-1（r=0.999 9）,5.948~237.924 μg·mL^-1（r=0.999 9）和0.854~25.607 μg·mL^-1（r=0.999 9）内线性关系良好;平均加样回收率分别为97.2%,102.1%和98.2%,RSD分别为1.7%,3.0%和1.0%。对来自2个企业的14批次样品进行测定,穿心莲内酯、脱水穿心莲内酯和异丹叶大黄素含量范围分别为每片0.80~2.43,0.59~2.71,和0.045~0.275 mg。结论 本方法准确可靠,可用于清感穿心莲片的质量控制。     

异丹叶大黄素在Caco-2细胞模型上转运机制的研究

异丹叶大黄素具有抗炎、抗氧化、抗癌等药理活性。该文研究了异丹叶大黄素在Caco-2细胞模型上的吸收转运机制。采用UPLC法,应用PDA检测器在310 nm处对异丹叶大黄素进行含量测定并计算表观渗透系数P_(app)。考察不同浓度异丹叶大黄素在Caco-2细胞上的毒性以确定转运实验的给药浓度。探讨了时间、浓度、温度、转运体抑制剂对异丹叶大黄素在体外细胞模型上跨膜转运的影响。实验结果表明,异丹叶大黄素在10~60μmol·L~(-1),孵育14 h内,对Caco-2细胞没有明显毒性。异丹叶大黄素在Caco-2细胞模型上的转运具有一定的浓度依赖性,其表观渗透系数P_(app)大于10×10~(-6)cm·s~(-1),易被Caco-2细胞吸收。BL侧的转运量在3 h达到最大值,6 h有所下降。4℃条件下,P_((app)(AP-BL))与P_((app)(BL-AP))均比37℃条件显著减小。加入P-gp转运体抑制剂维拉帕米后P_((app)(AP-BL))明显增大;加入MRP转运体抑制剂丙磺舒和MK-571后,P_((app)(BL-AP))明显减小。研究结果提示,异丹叶大黄素在Caco-2细胞模型上的转运方式主要是被动扩散,P-gp及MRP可能参与了异丹叶大黄素的外排转运。     

应用氧化偶联反应制备二苯乙烯类低聚化合物

目的　以异丹叶大黄素(isorhapontigenin)为反应物、FeCl₃为氧化剂进行氧化偶联反应,以期获得多种偶合产物,供观察其类似物的活性。方法　以FeCl_{31HNMR,¹³CNMR及¹³C-^{1相似文献}}   

异丹叶大黄素的体外抗氧化作用

 目的 异丹叶大黄素(isorhapontigenin, ISOR)是从中药射干中提取的化学成分,是与白藜芦醇化学结构相似的芪衍生物。通过多种模型研究ISOR的体外抗氧化作用。方法 采用Fe²⁺-半胱氨酸（Cys）、VitC-ADP-Fe²⁺和H₂O₂等自由基发生系统诱发大鼠肝微粒体、脑线粒体及突触体的氧化损伤,观察ISOR对此过程中MDA生成、GSH降低及超微弱化学发光增强的影响,并观察ISOR对用CuSO₄-Phen-VitC-H₂O₂系统损伤DNA后8-OH-dG的特征性超微弱化学发光增强影响。结果 ISOR能显著抑制Fe²⁺-Cys诱导的大鼠肝微粒体、脑线粒体及突触体膜氧化损伤过程中MDA的生成,并能显著抑制H₂O₂ 诱导的脑线粒体及突触体GSH的降低;显著抑制VitC-ADP-Fe²⁺系统引起的微粒体膜氧化损伤时超微弱化学发光增强,并能显著降低DNA受氧化损伤后微弱化学发光的强度。经典抗氧化剂VitE 10^-4mol·L^-1抑制MDA生成及GSH降低的作用仅相当于ISOR10^-5或10^-6 mol·L^-1的效果。结论 ISOR具有较强的抗氧化作用,且其活性明显强于经典抗氧化剂VitE。     

Piceatannol and Its Metabolite,Isorhapontigenin, Induce SIRT1 Expression in THP-1 Human Monocytic Cell Line

Piceatannol is a phytochemical that is present in large amounts in passion fruit (Passiflora edulis) seeds, and is an analog of resveratrol. Recently, the absorption and metabolism of piceatannol were investigated in rats, and isorhapontigenin, O-methyl piceatannol, was detected as a piceatannol metabolite in rat plasma. To elucidate the function of piceatannol and its metabolites, we investigated the expression of sirtuin 1 (SIRT1) in THP-1 monocytic cells after treatment with piceatannol and its metabolites, and compared their effects with those of resveratrol and its metabolites. Piceatannol and resveratrol upregulated the expression levels of SIRT1 mRNA and SIRT1 protein. An extract of passion fruit seeds, which contained high levels of piceatannol, also upregulated SIRT1 mRNA expression. As for the metabolites, isorhapontigenin upregulated SIRT1 mRNA expression, whereas resveratrol glucuronides and sulfate did not affect SIRT1 expression. These findings indicate that after intake of piceatannol, not only piceatannol itself, but also its metabolite, isorhapontigenin, contributed to the upregulation of SIRT1 expression.