New flavonol glycosides from leaves ofSymplocarpus renifolius

A study was carried out to evaluate flavonol glycosides in leaves ofSymplocarpus renifolius (Araceae). From the water fraction of the MeOH extract, three new flavonol glycosides were isolated along with three known compounds, kaempferol-3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-7-O-β-D-glucopyranoside, quercetin-3-O-β-D-glucopyranosy-l-(1→2)-β-D-glucopyranoside, and caffeic acid. The structures of the new flavonol glycosides were elucidated by chemical and spectral analyses as quercetin-3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-7-O-β-D-glucopyranoside, isorhamnetin-3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-7-O-β-D-glucopyranoside, and quercetin-3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-7-O-(6^IIII-trans-caffeoyl)-β-D-glucopyranoside.     

Protective effect of flavonoids against red blood cell hemolysis by free radicals

BACKGROUND:

Flavonoids are polyphenolic substances with antioxidant properties, and they are found in different vegetables and fruits. Epidemiological studies have shown that the consumption of flavonoids reduces the prevalence of cardiovascular diseases. The use of synthetic antioxidants, however, has been limited because of their toxicity. Therefore, medical researchers have intensified their quest to find natural antioxidants.

OBJECTIVES:

To investigate the effect of several pure flavonoids, such as kaempferol, quercetin, morin and rutin, on red blood cell hemolysis and evaluate their -SH capacity as an indicator of membrane protection.

METHODS:

The rate of hemolysis and cell membrane -SH capacity were determined by spectrophotometry. Red blood cell peroxidation was induced using 2,2′-azo-bis-(2-amidinopropane) dihydrochloride. The effect of each flavonoid on hemolysis was examined at three concentrations (0.5 μg/mL, 5 μg/mL and 10 μg/mL), however, only the greatest concentration (10 μg/mL) of each flavonoid was used to study the effect on -SH groups.

RESULTS:

In all cases, the antioxidant activity was dose-dependent. Rutin showed the highest inhibitory effect on hemolysis among flavonoids (42.5%). The protective effect of kaempferol, rutin and morin against -SH group oxidation measured 7.7%, 23.3% and 26.4%, respectively.

CONCLUSIONS:

Results showed that flavonoids and flavonoid-containing plants can be used as natural antioxidants for the treatment and prevention of disease conditions, the pathogenesis of which is mediated by lipid peroxidation.     

覆盆子活性成分山奈酚的含量测定

目的：建立覆盆子改善肾阳虚型痴呆活性成分山奈酚的含量测定方法。方法：采用高效液相色谱法。色谱柱为Diamon－sil C18（250mm ×4.6mm,5μm）,流动相：乙腈－0.1％磷酸水（30∶70）,流速1 mL／min,柱温30℃,检测波长266nm,进样量20μL。结果：山奈酚质量在0.0782～5.000μg范围内与峰面积呈良好的线性关系（r＝0.9999）,平均加样回收率为99.50％, RSD＝2.1％。结论：试验方法简便、快速、实验结果准确可靠,该方法可作为覆盆子有效成分山奈酚含量测定的方法。     

山萘酚对脂肪酸诱导的胰岛微血管内皮功能损伤的保护效应及多聚腺苷二磷酸核糖聚合酶1的作用机制

目的 探讨山萘酚对脂肪酸诱导的胰岛微血管内皮功能损伤的保护效应及多聚腺苷二磷酸核糖聚合酶1(PARP-1)的作用.方法 以小鼠胰岛微血管内皮MS-1细胞为研究对象,将细胞分为正常对照组、溶剂(DMSO)对照组、脂肪酸组(0.25 mmol/L软脂酸+0.5mmol/L油酸)、山萘酚组(50 μmol/L)、脂肪酸+山萘酚组、PARP-1抑制剂(8μmol/LBYK204165)+脂肪酸组和PARP-1抑制剂+脂肪酸+山萘酚组,分别检测各组细胞活力、凋亡水平、一氧化氮(NO)、一氧化氮合酶(NOS)及氧化应激相关指标的改变.结果 脂肪酸处理后,MS-1细胞存活率下降,细胞凋亡率升高(P＜0.05);同时,脂肪酸也增加了细胞内NO的含量,升高了总NOS(tNOS)、诱导型NOS(iNOS)和结构型NOS(cNOS)的活性(P＜0.05);促使脂质过氧化产物丙二醛(MDA)含量增加,抗氧化物质谷胱甘肽(GSH)和超氧化物歧化酶(SOD)的水平下降(P＜0.05);并增强了PARD-1、iNOS和cNOS的mRNA和蛋白表达水平(P＜0.05).而山萘酚干预后,各项指标的水平均得以改善(P＜0.05);而且,利用PARPP-1抑制剂BYK204165预处理1h,山萘酚对脂肪酸的拮抗效应更为显著,各项检测指标与正常对照组比较差异无统计学意义(P＞0.05).结论 脂肪酸可直接引起胰岛微血管内皮功能损伤,而山萘酚具有拮抗脂肪酸毒性的作用,且抑制PARP-1的表达水平能增强山萘酚的保护效应.     

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。     

山奈酚通过抑制NLRP3炎症小体介导的脂肪组织炎症改善db/db小鼠胰岛素抵抗发生

目的：探讨山奈酚能否通过调控肥胖小鼠脂肪组织炎症改善胰岛素抵抗发生并研究作用机制。方法：db/m小鼠作为对照组,db/db雄性小鼠随机分为模型组、二甲双胍组(0.15 g·kg^-1·d^-1)和山奈酚组(50 mg·kg^-1·d^-1)。连续灌胃给药6周,每周记录小鼠体重,6周后进行葡萄糖耐量试验、胰岛素耐量试验、皮下和附睾白色脂肪组织质量测定;HE染色观察脂肪组织形态学变化,免疫组化法观察巨噬细胞向脂肪组织的浸润程度及巨噬细胞标志物F4/80的表达,实时荧光定量PCR检测TNF-α和IL-18以及Arg-1和IL-10的mRNA表达,蛋白质免疫印迹试验检测NLRP3、pro-caspase1、cle-caspase1和IL-1β表达。结果：与模型组相比,山奈酚能够显著抑制db/db小鼠脂肪质量增加,抑制脂肪细胞肥大。山奈酚组小鼠脂肪组织巨噬细胞浸润减少,TNF-α和IL-18 mRNA表达减少,Arg-1和IL-10 mRNA表达增加;山奈酚治疗能够抑制小鼠附睾脂肪组织NLRP3、caspase1以及...     

Junctional adhesion molecule-like protein as a novel target for kaempferol to ameliorate lung adenocarcinoma

Objective: Although there have been improvements in targeted therapy and immunotherapy, the majority of lung adenocarcinoma(LUAD) patients still lack effective therapies. Consequently, it is urgent to screen for new diagnosis biomarkers and pharmacological targets. Junctional adhesion molecule-like protein(JAML) was considered to be an oncogenic protein and may be a novel therapeutic target in LUAD.Kaempferol is a natural flavonoid that exhibits antitumor activities in LUAD. However, the effect ...     

高效液相色谱法测定复方银杏叶片中银杏总黄酮的含量

目的建立复方银杏叶片中银杏总黄酮含量测定方法。方法采用高效液相色谱法,用Symmetry-C18色谱柱(250mm×4.6 mm,5μm),以甲醇-0.4%磷酸溶液(52∶48)为流动相,流速为1.0 ml.min-1,检测波长360 nm,柱温35℃。结果该法线性关系良好,平均加样回收率为98.35%,RSD为1.17%(n=5)。结论该法操作简便,分离效果好,结果准确,专属性强,可作为复方银杏叶片的质量控制方法。     

Kaempferol induces apoptosis in human lung non-small carcinoma cells accompanied by an induction of antioxidant enzymes.

Kaempferol (3, 4',5,7-tetrahydroxyflavone) is one of the most commonly found dietary flavonols. The biological and pharmacological effects of kaempferol may depend upon its behavior as either an antioxidant or a prooxidant. However, the clear biological effects of prooxidant or antioxidant character of kaempferol has not been clarified yet. The overall objective of the present study is to explore the role of prooxidant or antioxidant in kaempferol-induced cell toxicity. In this paper, we have proved that antioxidant pathway may be involved in kaempferol induces H460 cell apoptosis. Kaempferol-induced H460 cell apoptosis is a typical apoptosis that was accompanied by a significant DNA condensation and increasing intracellular ATP levels. Kaempferol-induced apoptosis is related to its ability to change the expression of apoptotic markers, such as caspase-3 (caspase-dependent) and AIF (caspase-independent). The overexpression of antioxidant enzyme Mn SOD protein levels, which was promoted to a new type tumor suppressor gene in several human cancer cells recently, may be an important role in kaempferol-induced H460 cell apoptosis.     

Modulation of suppressive activity of lipopolysaccharide-induced nitric oxide production by glycosidation of flavonoids

Flavonoids have been demonstrated to exhibit a wide range of biological activities including anti-inflammatory and neuroprotective actions. Although a significant amount of flavonoids has been identified to be present as glycosides in medicinal plants, determinations of the biological activities of flavonoids were mainly carried out with aglycones of flavonoids. Therefore, the exact role of the glycosidation of flavonoid aglycones needs to be established. In an attempt to understand the possible role of glycosidation on the modulation of the biological activities of flavonoids, diverse glycosides of kaempferol, quercetin, and aromadendrin were examined in terms of their anti-inflammatory activity determined with the suppression of lipopolysaccharide (LPS)-induced nitric oxide (NO) production in BV2 microglial cells. The results indicated that glycosidation of aglycones attenuated the suppressive activity of aglycones on LPS-induced NO production. Although attenuated, some of glycosides, depending on the position and degree of glycosidation, maintained the inhibitory capability of LPS-induced NO production. These findings suggest that glycosidation of flavonoid aglycones should be considered as an important modulator of the biological activities of flavonoids.