异丹叶大黄素在抗肿瘤作用机制中的研究进展

作为一种从中药射干、买麻藤及葡萄中提取的天然中药单体,近来发现异丹叶大黄素(ISO)对膀胱癌、前列腺癌、神经胶质细胞瘤等肿瘤的生长增殖、凋亡、自噬等致瘤过程起重要作用。本文回顾了近几年异丹叶大黄素在抗肿瘤作用机制中的研究成果并展望了异丹叶大黄素今后研究与应用所面临的挑战。     

异丹叶大黄素对前列腺癌细胞血管生成相关蛋白的影响

目的探讨异丹叶大黄素对前列腺癌细胞血管生成相关蛋白缺氧诱导因子1α(hypoxiainduciblefactor-1α,HIF-1α)、血管内皮生长因子(vascular endothelial growth factorα,VEGF-α)、上皮细胞激酶-2(erythropoietin producing human hepatocelluar A2,EphA2)、人基质金属蛋白酶2(Mateixmetalloproteinases 2,MMP2)表达水平的影响。方法选取LNCAP细胞,传代培养后进行siRNA转染,将细胞分为空白对照组、HIF-1αsiRNA组、VEGF-αsiRNA组、EphA2 siRNA组、MMP2 siRNA组、异丹叶大黄素组、异丹叶大黄素+HIF-1αsiRNA组、异丹叶大黄素+VEGF-αsiRNA组、异丹叶大黄素+EphA2 siRNA组,采用Western Blot检测HIF-1α、VEGF-α、EphA2、MMP2的蛋白表达水平。结果与空白组(0.6138±0.0316)相比,HIF-lαsiRNA组(0.0317±0.0019)、异丹叶大黄素+HIF-lαsiRNA组(0.0372±0.0172)HIF-1α蛋白表达水平明显降低,差异有统计学意义(P0.05);与空白组(0.0678±0.0049)相比,VEGF-αsiRNA组(0.0159±0.0006)、异丹叶大黄素+VEGF-αsiRNA组(0.0112±0.0007)VEGF-α蛋白蛋白表达水平明显降低,差异有统计学意义(P0.05);与空白组(0.1685±0.0125)相比,EphA2siRNA组(0.1365±0.0287)、异丹叶大黄素+EphA2 siRNA组(0.1655±0.0388)EphA2蛋白表达量差异无统计学意义(P0.05)。HIF-lαsiRNA组、VEGF-αsiRNA组、EphA2 siRNA组MMP2蛋白表达量与空白组相比,差异有统计学意义(P0.05)。结论异丹叶大黄素通过抑制HIF-1α、VEGF-α、EphA2、MMP-2蛋白的表达,抑制前列腺癌的血管拟态形成,从而抑制前列腺癌的发生发展。     

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。     

峨眉桃叶珊瑚果实提取物体外抗氧化活性研究

目的:测定峨眉桃叶珊瑚果实的抗氧化活性,为峨眉桃叶珊瑚果实的开发利用提供依据.方法:采用化学发光法,运用邻苯三酚-鲁米诺化学发光体系、亚铁氰化钾-鲁米诺-过氧化氢体系与过氧化氢-鲁米诺体系测定峨眉桃叶珊瑚果实不同提取部位对超氧负离子、羟自由基与过氧化氢的清除作用.结果:峨眉桃叶珊瑚果实的不同提取部位对超氧负离子与过氧化氢均具有较强的清除作用. 结论:峨眉桃叶珊瑚果实具有明显的抗氧化活性.     

姜油体外抗氧化活性和对细胞DNA损伤防护作用的实验研究

目的 :探讨姜油的体外抗氧化活性和对DNA损伤的防护作用。方法 :采用化学发光法测定姜油对氧自由基的清除能力 ;用比色法检测对人红细胞溶血和兔肝匀浆丙二醛 (MDA )生成的影响 ;采用单细胞凝胶电泳法检测对淋巴细胞DNA损伤的影响。结果 :与对照组比较 ,姜油可明显抑制本底的发光强度 ;对H₂O₂ 诱导的红细胞溶血和DNA损伤有明显的抑制作用 ;且能抑制兔肝匀浆MDA的生成 ,抑制率为 48.16%。结论 :姜油具有较强的氧自由基清除能力和防护DNA损伤的作用 ,是天然的抗氧化剂 ,具有很大的开发应用价值。     

滁菊叶化学成分及其体外抗氧化活性研究

目的:对滁菊叶的化学成分进行研究。方法:通过硅胶、Sephadex LH-20、制备高效液相等方法,对滁菊叶乙醇提取物进行分离纯化,根据理化性质和波谱数据鉴定化合物结构;以DPPH·自由基清除能力检测所得化合物的抗氧化能力。结果:从滁菊叶乙醇提取物中分离鉴定了21个化合物,分别为:二十八烷醇(1)、β-谷甾醇(2)、羽扇豆醇(3)、α-香树脂醇(4)、胡萝卜苷(5)、ineupatorolide B(6)、紫丁香苷(7)、绿原酸(8)、petasiphenol(9)、大黄素甲醚(10)、金合欢素(11)、异泽兰黄素(12)、槲皮素(13)、香叶木素(14)、木犀草素(15)、芹菜素(16)、芹菜素-7-O-β-D-葡萄糖苷(17)、槲皮素-3-O-β-D-葡萄糖苷(18)、木犀草素-7-O-β-D-葡萄糖苷(19)、芹菜素-7-O-β-D-新橙皮糖苷(20)、金合欢素-7-O-β-D-葡萄糖苷(21)。结果:其中,化合物1~12、18和20为首次从滁菊中分离得到。化合物10、13~16表现出显著的自由基清除能力,活性强于Vit C。     

贯叶连翘标准提取物体外抗氧化活性

贯叶连翘Hypericum perforatum L．为藤黄科金丝桃属植物，又名千层楼、圣约翰草等，地上部分或全草入药，其性平味涩，有清热解毒、收敛止血、利湿之功效。其主要成分有苯并二蒽酮类、黄酮类、挥发油类和间苯三酚类。贯叶连翘富含黄酮类化合物，高达11．7％，主要为金丝桃苷、槲皮素、槲皮苷及芦     

3种大黄素金属配合物的抗氧化活性研究

目的:对比配体大黄素和其3种金属配合物的体外抗氧化活性.方法:以天然大黄素和相应的金属盐为原料,在无水乙醇中合成了大黄素-锌、大黄素-锰、大黄素-铁(Ⅲ)等3种配合物,并对其结构进行表征.采用紫外可见分光光度法,分别考察了配体和配合物对二苯代苦味肼基自由基(DPPH)、超氧自由基(O2-·)、羟基自由基(·OH)等3种自由基的清除率.结果:配体及配合物对3种自由基均有一定清除作用.其中大黄素-铁(Ⅲ)清除羟基自由基活性最强,其半数有效浓度(EC50)值达19.96 mg·L-1小于大黄素(EC50147.87 mg·L-1)、大黄素-锌(EC50 30.76 mg·L-1)、大黄素-锰(EC50 100.04 mg·L-1);大黄素-铁(Ⅲ)清除超氧自由基活性也为最强,其EC50达60.832 mg·L-1,小于大黄素(EC50853.152 mg·L-1)、大黄素-锌(EC50436.296mg·L-1)、大黄素锰(EC50 161.949 mg·L-1);实验范围内(1×10-4mmol·L-1≤C≤4×10-3 mmol·L-1)配合物和配体对DPPH自由基清除活性总体不强,均小于25％,但配合物活性稍高于配体.结论:大黄素与Fe3+,Zn2+,Mn2+离子形成配合物后抗氧化活性增强,其中以大黄素-铁(Ⅲ)配合物抗氧化活性最高.     

桃叶鸦葱鞣质的提取及体外抗氧化作用

目的:测定桃叶鸦葱根及地上部分中鞣质的含量,考察鞣质抗氧化活性.方法:采用正交设计优化鞣质提取工艺,采用络合滴定法测定鞣质含量.采用碘量法测定0.01～0.05 g·mL-1鞣质对过氧化氢(H2O2)的作用,采用分光光度法测定其对羟自由基(·OH)的作用.结果:桃叶鸦葱根及地上部分中鞣质含量分别为8.18％和9.27％.桃叶鸦葱鞣质的体外抗氧化具一定的剂量依赖性,质量浓度为0.05 g·mL-1时对H202及·OH的平均清除率分别达到8.89％,88.24％.结论:桃叶鸦葱鞣质有一定抗氧化作用.     

针灸抗氧化作用的研究概况

对近年来针灸抗氧化作用在心血管疾病、神经系统疾病、消化系统疾病等疾病的研究进展加以总结。研究表明,针灸可以提高抗氧化酶活性,减少自由基的产生,增强机体抗氧化能力。今后应在有机结合临床和动物研究的基础上,从氧化损伤标志物、氧化还原平衡、自由基相关信号转导通路等多角度,进一步深化针灸抗氧化作用的研究。     

Evaluation of the in vitro antioxidant activity in extracts of Uncaria tomentosa (Willd.) DC.

Different extracts of U. tomentosa were tested in vitro for their antioxidant activity utilizing tert -butyl-hydroperoxide-initiated chemiluminescence in rat liver homogenates. Methanol fractions of both stem-bark and roots were capable of exerting antioxidant activity by this technique. The presence of different concentrations of bark and root methanol extracts also prevented TBARS production and free radical-mediated DNA-sugar damage. © 1997 John Wiley & Sons, Ltd.     

Antioxidative and antiinflammatory potential of different functional drink concepts in vitro

The present study was undertaken to investigate the antioxidative effects of three different functional drink concepts especially designed to improve the body's performance and function and to possess high antioxidant activities. The concepts based on the mixture of various plant ingredients were: (1) eQ - equalize your nutrient balance, brain line [acerola-dragon fruit], (2) eQ - equalize your nutrient balance, beauty line [honey-pepper] and (3) Let's get red [intense]. By using a cell-based test assay, the study investigated the potential of the functional drinks to inactivate reactive superoxide anion radicals generated by inflammation-mediating cells as well as the effect on basal metabolism of these cells (antioxidant and antiinflammatory potential). In addition, by using a cell-free test assay the potential of the drinks to inactivate free exogenous superoxide anion radicals (scavenger effect) was investigated. The data presented here demonstrate the different radical scavenging, antioxidant and anti-inflammatory potential of the functional drink concepts. In particular Let's get red [intense] turned out to be the most potent drink in this respect and demonstrated marked efficacy in scavenging, antioxidant and antiinflammatory action.     

Antioxidative and in vitro hepatoprotective activity of Bupleurum kaoi leaf infusion

The roots of Bupleurus spp. have been used in traditional Chinese herbal medicine for curing liver diseases. Although bioactive saikosaponins have been detected in the leaves as well as in the roots, the aerial parts of the plants are discarded as waste. In the present study, a leaf infusion of B. kaoi Liu, Chao et Chuang, an indigenous Bupleurus species in Taiwan, was prepared and the antioxidant properties and in vitro hepatoprotective activity were demonstrated. The results show that the leaf infusion exerted DPPH free radical scavenging activity, inhibitory capacity on superoxide anion formation and superoxide anion scavenging activity. The hepatotoxicity of acetaminophen (APAP) and carbon tetrachloride (CCl4) on the rat liver cells were also decreased by the leaf infusion.     

化学发光法测定白果白蛋白的体外抗氧化活性

目的研究白果白蛋白的体外抗氧化活性、对DNA损伤的保护作用及其作用机制。方法以莲房原花青素和小牛血清蛋白为对照,分别采用邻苯三酚-鲁米诺化学发光体系测定了白果白蛋白对超氧阴离子的清除作用,硫酸铜-邻菲啉-抗坏血酸-双氧水、硫酸亚铁-鲁米诺-双氧水和硫酸亚铁-鲁米诺3个体系测定了白果白蛋白对羟自由基的清除作用,双氧水-鲁米诺体系测定了白果白蛋白对体外双氧水的清除作用,采用硫酸铜-邻菲啉-抗坏血酸-双氧水-脱氧核糖核酸体系测定了白果白蛋白对体外DNA损伤的保护作用。结果白果白蛋白具有较好的体外清除活性氧和保护DNA损伤的活性,但在硫酸亚铁-鲁米诺-双氧水和双氧水-鲁米诺化学发光体系中表现出"促氧化"作用。结论采用化学发光体系衡量白果白蛋白的抗氧化活性具有选择性。     

Antioxidative activity of flavones and flavonols in vitro

Forty-one flavonoids of the flavone and flavonol types were investigated for their antioxidative activity using a lipid peroxidation generation system mediated by the addition of H₂O₂/Fe²⁺ to rat liver homogenate. The results showed that both types specifically and markedly reduced the production of peroxidants induced by H₂O₂, Fe²⁺ or a Fenton-type reaction. The scavenging ability of these compounds was found to be associated closely with their chemical structure, especially the number of hydroxyl groups linked to the basic skeleton. However, there were some exceptions, implying that not only hydroxyl groups but also their configuration determines the activity. © 1997 John Wiley & Sons, Ltd.     

Antioxidant activity of Osbeckia aspera

Plants of the Osbeckia family have been shown to possess hepatoprotective properties, which could be due to the presence of antioxidant compounds. The plant extract was shown to inhibit significantly in a dose-dependent manner, the activities of the DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical (EC₅₀ of 27.5 μg/mL), xanthine oxidase (EC₅₀ of 1.16 mg/mL) and demonstrate a scavenging effect on hydroxyl radical mediated damage to deoxyribose (EC₅₀ of 140 μg/mL). The plant extract possessed some prooxidant activity from the effect on bleomycin-induced DNA damage, but this was less than that shown by comparable concentrations of (+)-catechin or silymarin. © 1998 John Wiley & Sons, Ltd.     

Effects of extracts of Tanacetum species on human polymorphonuclear leucocyte activity in vitro

The inhibitory effects of whole and fractionated acetone extracts of leaves of four species of Tanacetum were assessed in vitro, using a human polymorphonuclear leucocyte-based bioassay. Biochemical investigation detected the bioactive germacranolide, parthenolide, at high concentrations, in extracts from T. parthenium and T. niveum (1.72%±0.16% and 2.62%±0.23% leaf dry weight, respectively; n =5). The compound was present at much lower concentrations (<0.03% leaf dry weight) in extracts of T. ptarmiciflorum and T. vulgare. All extracts inhibited phorbol myristate acetate-induced chemiluminescence of human polymorphonuclear leucocytes, with IC₅₀s from 0.79±0.19 to 2.46±0.39 mg leaf dry weight/mL whole blood for T. parthenium and T. vulgare, respectively. Fractionation of crude leaf extracts revealed a number of fractions, in addition to those containing parthenolide, which influenced polymorphonuclear leucocyte activity by > 5%. Such fractions presumably contained compounds that augmented the pharmacological activity of extracts beyond that predicted on the basis of parthenolide content alone, and were responsible, in part, for the pharmacological activity of the extracts lacking parthenolide. These effects on phorbol myristate acetate-induced chemiluminescence suggested the activity of the responsible compound(s) was a result of inhibition of protein kinase C, or subsequent events, in polymorphonuclear leucocyte activation in vitro. © 1997 John Wiley & Sons, Ltd.     

Inhibition of lipid peroxidation and oxidative DNA damage by Ganoderma lucidum

Reactive oxygen species (ROS), such as superoxide anions and hydroxyl radicals, are associated with carcinogenesis and other pathophysiological conditions. Therefore, elimination or inactivation of ROS or inhibition of their excess generation may be beneficial in terms of reducing the risk for cancer and other diseases. Ganoderma lucidum has been used in traditional oriental medicine and has potential antiinflammatory and antioxidant activities. In the present study, we tested the amino-polysaccharide fraction (designated as 'G009') from Ganoderma lucidum for the ability to protect against oxidative damage induced by ROS. G009 significantly inhibited iron-induced lipid peroxidation in rat brain homogenates and showed a dose-dependent inactivation of hydroxyl radicals and superoxide anions. It also reduced strand breakage in phiX174 supercoiled DNA caused by UV-induced photolysis of hydrogen peroxide and attenuated phorbol ester-induced generation of superoxide anions in differentiated human promyelocytic leukaemia (HL-60) cells. These findings suggest that G009 from Ganoderma lucidum possesses chemopreventive potential.     

黄芩苷的体外抗氧化研究

目的 研究黄芩苷体外抗氧化作用.方法 取不同浓度的黄芩苷溶液,采用DPPH法测定黄芩苷自由基清除能力,用试剂盒测定黄芩苷抗超氧阴离子和总抗氧化能力,通过检测尿酸生成来测定黄芩苷对黄嘌呤氧化酶活性的影响等.结果 黄芩苷具有显著的总抗氧化能力,且呈明显的量效关系;黄芩苷对自由基和超氧阴离子有较好的清除能力;另外,黄芩苷对黄嘌呤氧化酶(XOD)有抑制作用,黄嘌呤氧化酶催化黄嘌呤氧化生成尿酸的含量随黄芩苷浓度升高而降低.结论 黄芩苷可以直接清除自由基、超氧阴离子等氧自由基,抑制黄嘌呤氧化酶活性,是良好的抗氧化剂.