Correlations between polyphenolic composition and antioxidant activity of Venetian propolis

Four propolis samples have been picked up in the Venetian region, from different orography and habitative density areas with the purpose to: (i) evaluate propolis’ antioxidant activity, measured by inhibition of lipid peroxidation; (ii) determine the polyphenolic components – flavonoids and caffeic acid derivatives – which give antioxidant activity to propolis; (iii) verify the potential correlations between antioxidant activity, polyphenolic content, that has been determined by Folin–Ciocalteu, enzymatic, DPPH quenching, TEAC-like assays, and spectroscopic characteristics of propolis and (iv) correlate chemical structure and antioxidant efficacy of each of the major components. The possible localization of the lipophylic components of propolis into the phospholipidic bilayer by thermal analysis (DSC) and spin label EPR techniques has also been investigated.     

Vane’s blood-bathed organ technique adapted to examine the endothelial effects of cardiovascular drugs in vivo

This study describes a modification of Vane’s blood-bathed organ technique (BBOT). This new technique consisted of replacing the cascade of contractile smooth muscle organs within the traditional BBOT by a single collagen strip cut from a rabbit’s hind leg tendon. Utilizing the extracorporeal circulation of an anesthetized heparinized mongrel cat or Wistar rat, arterial blood was dripped (1–3 ml min^–1) over a collagen strip. This resulted in a gain in weight of the strip, which was due to the deposition of platelet aggregates and a few blood cells trapped over the strip. Arterial blood that had been used for the superfusion was pumped back into the animal’s venous system. However, when this technique is adapted to human volunteers, the superfusing blood should be discarded. In animal experiments, intravenous injections of a variety of classic fibrinolytic agents (e.g., streptokinase) promoted the formation of platelet thrombi. Nitric oxide donors (e.g., SIN-1) at non-hypotensive doses hardly affected the mass of platelet thrombi deposited over the collagen strip, whereas endogenous prostacyclin (e.g., released from vascular endothelium by bradykinin) or exogenous prostacyclin and its stable analogues (e.g., iloprost) dissipated platelet thrombi as measured by a loss in the weight of the blood superfused collagen strip. This model allowed us to assay numerous drugs for their releasing properties of endogenous prostacyclin from vascular endothelium. These drugs included lipophilic angiotensin converting enzyme inhibitors (ACE-Is), which act in vivo as bradykinin potentiating factors (BPF). Other PGI₂-releasers included statins (e.g., atorvastatin and simvastatin), thienopyridines (e.g., ticlopidine and clopidogrel), a number of thromboxane synthase inhibitors, flavonoids, bradykinin itself, cholinergic M receptor agonists and nicotinic acid derivatives. The thrombolytic actions of lipophilic ACE-Is (e.g., quinapril and perindopril) were prevented by pretreatment with either bradykinin B₂ receptor antagonists (e.g., icatibant) or with endothelial COX-2 inhibitors (e.g., rofecoxib, celecoxib and high dose aspirin). The inhibition of endothelial nitric oxide synthetase (eNOS) by L-NAME hardly blunted the thrombolytic response to ACE-Is. Hence, it can be concluded that many recognized cardiovascular drugs apart from their known basic mechanisms of action, may also behave as releasers of endogenous endothelial prostacyclin. Furthermore, in many instances, this effect may be the primary mechanism of their therapeutic efficacy.     

狭叶香蒲花粉(蒲黄)黄酮类成分的研究

自香蒲科(Typhaceae)植物狭叶香蒲(Typha augustifolia L.)的干燥花粉中分离到五个黄酮醇甙,包括两个黄酮醇-3-三糖甙(Ⅰ,Ⅱ)和三个黄酮醇-3-双糖甙(Ⅲ,Ⅳ,Ⅴ)。其中,化合物Ⅰ是一个新的黄酮醇甙,为本植物的主要成分,经光谱分析(UV,IR.MS;¹HNMR和¹³CNMR)和水解试验确定为异鼠李素-3-0-(2_G-α-L-鼠李糖基)-α-L-鼠李糖(1→6)-β-D-葡萄糖甙,命名为香蒲新甙(typhaneoside,Ⅰ)。其它四种为已知成分。Ⅱ从本属植物中首次发现。     

微波辅助提取麦冬黄酮的工艺研究

目的:研究微波辅助法提取麦冬黄酮的工艺条件。方法:采用单因素试验,探讨料液比、微波处理时间、微波强度以及乙醇体积分数对麦冬黄酮提取量的影响,并与传统回流法进行比较。结果:微波提取优化工艺条件为:乙醇体积分数为90%,料液比为1:14(g/ml),微波功率为中档,微波提取时间4min。微波处理后再进行回流提取较不经微波处理得到提取物的黄酮含量高出39.7%。结论:微波辅助法是一种提取麦冬黄酮的有效方法。     

Prospective cohort comparison of flavonoid treatment in patients with resected colorectal cancer to prevent recurrence

AIM： To investigate biological prevention with flavonoids the recurrence risk of neoplasia was studied in patients with resected colorectal cancer and after adenoma polypectomy. METHODS： Eighty-seven patients, 36 patients with resected colon cancer and 51 patients after polypectomy, were divided into 2 groups： one group was treated with a flavonoid mixture （daily standard dose 20 mg apigenin and 20 mg epigallocathechin-gallat, n = 31） and compared with a matched control group （n = 56）. Both groups were observed for 3-4 years by surveillance colonoscopy and by questionnaire. RESULTS： Of 87 patients enrolled in this study, 36 had resected colon cancer and 29 of these patients had surveillance colonoscopy. Among the flavonoid-treated patients with resected colon cancer （n = 14）, there was no cancer recurrence and one adenoma developed. In contrast the cancer recurrence rate of the 15 matched untreated controls was 20% （3 of 15） and adenomas evolved in 4 of those patients （27%）. The combined recurrence rate for neoplasia was 7% （1 of 14） in the treated patients and 47% （7 of 15） in the controls （P = 0.027）. CONCLUSION： Sustained long-term treatment with a flavonoid mixture could reduce the recurrence rate of colon neoplasia in patients with resected colon cancer.     

Comparative effects of catechin,epicatechin and N-Ω-nitroarginine on quinolinic acid-induced oxidative stress in rat striatum slices

The aim of this work was to compare the effects of catechin (CAT), epicatechin (EPI) and N-ω-l-nitroarginine (L-NARG) on different endpoints of oxidative stress induced by quinolinic acid (QUIN) in a simple tissue preparation, rat striatal slices – with particular emphasis in the glutathione system – in order to provide revealing information on the antioxidant efficacy of these agents in an excitotoxic model.MethodsRat striatal slices were incubated for 1 h in the presence of 100 μM QUIN and/or 85 μM CAT or EPI, or 100 μM L-NARG. Lipid peroxidation (LP) and the levels of reduced and oxidized glutathione (GSH and GSSG) were determined.ResultsThe three agents tested completely blocked the QUIN-induced lipid peroxidation and recovered the QUIN-induced altered GSH/GSSG balance. No statistical differences were detected among the protective effects exerted by these antioxidants, suggesting similar efficacy and common antioxidant mechanisms. The antioxidant properties exhibited by these molecules on the excitotoxic model tested herein support an active role of glutathione and prompt their use as therapeutic tools in models of neurodegenerative disorders.     

飞燕草不同部位总黄酮的提取与含量测定

目的：提取飞燕草不同部位总黄酮,并对其进行含量测定,最终确定飞燕草最佳药用部位。方法：采用乙醇回流提取法提取飞燕草不同部位总黄酮,以芦丁为标准品,应用紫外分光光度法测定飞燕草全草、根、茎、叶及花中的总黄酮含量。结果：飞燕草全草、根、茎、叶及花等部位总黄酮含量分别为56.2%、47.6%、49.8%、51.3%、65.8%。结论：飞燕草不同部位中均含有总黄酮,其中花中总黄酮含量最高,根中最少,但考虑到不同部位的产量,建议以全草入药。     

沙苑子黄酮对辐射损伤的抗氧化保护作用

目的研究沙苑子黄酮（flavonoids of Astragali complanali,FAC）的抗辐射作用。方法雌性昆明小鼠随机分为正常组、模型组、阳性对照组（利血生组）、FAC-1组、FAC-2组、FAC-3组等6组,分别给予相应的药物干预。第7天除正常对照组外各组小鼠均接受6 GY60Coγ射线一次性全身照射。对各组小鼠肝脏HE染色切片观察FAC对辐射损伤的保护效应。采用试剂盒测定小鼠肝脏匀浆中超氧化物歧化酶（SOD）水平、谷胱甘肽过氧化物酶（GSH-Px）抗氧化酶的活力、脂质过氧化产物丙二醛（MDA）的含量和总抗氧化能力（T-AOC）的变化情况。采用分光光度法测定H2O2诱导的红细胞溶血、Fe2＋-Vit C诱导的肝线粒体肿胀度以及O2-,.OH和DPPH变化情况。结果与正常组比较,辐射能够引起小鼠血象指标及生理结构的显著改变（P〈0.05,P〈0.01）;氧化能够在体外引起自由基和溶血及线粒体肿胀的发生（P〈0.01）。与模型组比较,FAC增强了SOD、GSH-Px活力,降低MDA的含量（P〈0.01）;高剂量FAC的作用普遍强于阳性对照药（P〈0.05）。FAC有很强的清除自由基的作用,对3种自由基的清除率都达到60%以上,其中对DPPH的清除率达到90%,高剂量FAC的作用要强于阳性对照组（P〈0.05,P〈0.01）。与模型组比较,FAC抑制线粒体肿胀和红细胞溶血的作用为50%（P〈0.01）;高剂量FAC的作用与阳性对照药相似。HE切片显示FAC能显著减轻辐射对小鼠肝脏造成的坏死、肿胀、炎症浸润。各FAC组之间有随着给药剂量增加而作用增加的剂量依赖关系（P〈0.05,P〈0.01）。结论 FAC对辐射小鼠有保护作用,其作用机制与提高抗氧化能力、保护细胞及组织的正常形态和功能有关。     

HPLC法测定菊苣中黄酮类成分的含量

目的：建立HPLC法测定菊苣中黄酮类成分含量的方法。方法：色谱柱：Scienhome C18（4.6mm×200mm,5μm）,检测波长350nm;柱温30℃;流速1mL/min。结果：木犀草素-7-O-β-D-葡萄糖苷在0.0024～0.0192μg内线性良好,y=2000000x-443.39r,=0.9999,回收率为102.7%,RSD为0.82%;木犀草素在0.01464-0.11712μg内线性良好,y=2000000x-2058.1r,=0.9999,回收率为103.4%,RSD为0.52%。结论：采用该方法进行含量测定准确可靠,重现性好。     

Simultaneous quantification of eight major constituents in Herba Siegesbeckiae by liquid chromatography coupled with electrospray ionization time-of-flight tandem mass spectrometry

A simple and reliable high-performance liquid chromatography coupled with electrospray ionization time-of-flight tandem mass spectrometry method was developed and validated for the determination of the major diterpenoids and flavonoids in the aerial parts of Herba Siegesbeckiae, including Kirenol, hythiemoside B, ent-16β,17,18-trihydroxy-kauran-19-oic acid, ent-17,18-dihydroxy-kauran-19-oic acid, ent-16β,17-dihydroxy-kauran-19-oic acid, 16α-hydro-ent-kauran-17,19-dioic acid, Rhamnetin, 3',4'-dimethoxy quercetin. The separation of eight compounds was performed on a Waters Symmetry Shield TM RP18 column (250mm×4.6mm i.d., 5μm) with gradient elution using a mobile phase consisting of 0.1% aqueous formic acid and acetonitrile containing 0.1% formic acid in selected ion monitoring mode. All calibration curves showed good linearity (r>0.999) within the test ranges. The precision was evaluated by intra- and inter-day tests, which revealed relative standard deviation (RSD) values less than 3.7%. The recoveries for the quantified compounds were between 97.4 and 101.2% with RSD values below 2.4%. According to the literatures, this study represents the first investigation of the simultaneous analysis of multiple components and the method can be applied to determine the amounts of the major compounds in Herba Siegesbeckiae.