大蒜素对人胰腺癌PANC-1细胞株的作用及机制的研究

<正>大蒜素是新鲜大蒜中主要生物活性成分的总称,其中主要成分为二烯丙基三硫化物(DADS)。大蒜除有健胃助消化的功能,还有抗真菌[1]、抗细菌、降血脂[2]、降血压、抑制血小板聚集和防止动脉粥样硬化[3]等作用。近年来,大蒜的抗肿瘤     

大蒜多糖对阿霉素所致心肌细胞损伤的保护作用

目的观察大蒜多糖(GP)对阿霉素(ADR)中毒心肌细胞的保护作用并探讨其机制。方法采用0~2 d SD乳鼠心肌细胞做原代培养,复制ADR损伤心肌细胞模型,测定上清液及细胞中多项生化指标,并运用MTT比色法、流式细胞仪检测凋亡细胞。结果ADR(终浓度为1 mg.L-1)可致上清液肌酸激酶(CK)、乳酸脱氢酶(LDH)、谷草转氨酶(GOT)释放量增加(P<0.01),同时细胞超氧化物歧化酶(SOD)活力下降而丙二醛(MDA)含量升高(P<0.01),GP(25~100 mg.L-1)可呈浓度依赖性地降低CK、LDH、GOT活力,增加细胞SOD活力和降低MDA含量,尤其以GP大剂量组作用明显(P<0.05或P<0.01)。流式细胞仪检测GP能降低心肌细胞凋亡率,证实了GP的保护作用。结论GP能够拮抗ADR引起的自由基脂质过氧化,从而保护心肌细胞。     

健康大蒜的7种做法

【大蒜食疗作用】 1．消炎杀菌 大蒜挥发油所含大蒜辣素等具有明显的抗炎灭菌作用，尤其对上呼吸道和消化道感染、霉菌性角膜炎、隐抱子菌感染有显著的功效。 2．降血脂，抗动脉硬化 大蒜有效成分能显著降低高脂血症，提示大蒜具有降血脂、抗动脉粥样硬化的作用。 3．预防肿瘤，抗癌 大蒜素及其同系物能有效地抑制癌细胞活性，使之不能正常生长代谢，最终导致癌细胞死亡；大蒜液能阻断霉菌使致癌物质硝酸盐还原为亚硝酸盐而防治癌肿；大蒜中的锗和硒等元素有良好的抑制癌瘤或抗癌作用；大蒜素还能激活巨噬细胞的吞噬能力，增强人体免疫功能，预防癌症的发生。     

放置的大蒜提取液抗氧化、抗肿瘤及降血脂的机制

目的：综述放置提取液抗氧化及抗肿瘤、降血脂的机制。方法；查询国外献，探讨放置的大蒜提取液的抗氧化机制及抗肿瘤、降血脂的作用。结果：放置的大蒜提取液有抗氧化作用，可以阻断早期和晚期肿瘤在许多组织中生长，可以降低低密度脂蛋白的氧化修饰。结论：长期放置的大蒜提取液具有广泛的抗氧化作用，降能代血脂，降低肿瘤发病率。     

大蒜的化学成分及药理研究

大蒜是百合科葱属植物蒜(Allium sativum L)的鳞茎。它不仅作为膳食的常用佐料,也是常用的中药之一。对大蒜的化学成分、药理作用等方面的研究结果表明:大蒜不但具有抗菌、抗真菌、抗肿瘤、免疫应激等效应,而且还有抗血栓、降血脂、扩血管以及抑制血管平滑肌细胞(VSMC)增殖等效应。     

大蒜多糖对阿霉素所致小鼠心脏毒性的拮抗作用

目的　研究大蒜多糖 (GP)对中毒性心肌炎的拮抗作用并探讨其机制。方法　建立小鼠阿霉素 (ADR)中毒性心肌炎模型,测定血清、心肌多项生化指标,并观察心肌结构变化。结果　ADR(3mg·kg-1ip, qod×7)可致小鼠血清肌酸激酶(CK)、乳酸脱氢酶(LDH)、谷草转氨酶(GOT)和诱导型一氧化氮合酶(iNOS)活力升高(P<0 01),同时心肌超氧化物歧化酶(SOD)活力下降而丙二醛 (MDA)含量升高 (P<0 01),线粒体水肿明显。GP( 0 75 ~3 0g·kg-1 ig, qd×15)能逆转ADR所致的上述改变,表现为剂量相关性降低血清CK、LDH、GOT和iNOS活力,增加心肌SOD活力和降低MDA含量,尤其以GP大剂量组作用明显 (P<0 05或P<0 01)。光镜和电镜结果也证实了GP的保护作用。结论　GP能拮抗阿霉素所致的小鼠中毒性心肌炎,其作用机制与增强心肌SOD活力和抗心肌脂质过氧化有关。     

大蒜的药理作用及临床应用

大蒜系百合科葱属多年生草本植物大蒜的地下鳞茎.味辛、性温,有解毒、杀虫之功效.传统主要用于治疗疮痈和痢疾。现代药理研究证实,大蒜具有抗菌、抗原虫、抗滴虫、抗肿瘤、降血脂、降血压等作用.本文对其药理作用及临床应用简述如下:一、抗菌消炎作用大蒜中含有多种氨基酸,如蒜氨酸、丙     

大蒜素对离体蟾蜍皮肤钠转运的抑制作用

大蒜具有抗感染、抗肿瘤、降血脂和降血糖、抗血栓形成及抗动脉粥样硬化作用。大蒜提取物(GE)及口服大蒜粉末对麻醉狗具有很强的利尿和利钠作用,本文用离体蟾蜍皮肤研究了大蒜水提物的利钠作用机制。大蒜切碎后在两倍体积的蒸馏水中匀浆化,65C加热5rain,过滤、透析并浓缩至较小体积。透析液通过用0.01mool/L乙酸铵缓冲液平衡pH7.4的TSK650柱层析。所得活性部分再通过用0.01～0.1mol/L乙酸铵平衡pH4.7～7.6的TSK-DEAE650柱层析,所分离得到的活性部分用于实验。蟾蜍(9～25g)的腹部皮肤固定于两小室中问,两室均盛入pH7.5的Ring''s缓冲液,记录皮肤两侧的电位差(PD)及跨皮短路电流(SCC),当GE加入到皮外侧小室中时,引     

蒜素和依那普利对果糖诱导的大鼠高胰岛素、高血脂、高血压的作用

大蒜在世界各地被广泛用作调味品、食品和家庭保健品。有研究显示 ,大蒜的心脏保护作用在于它具有降血脂、降血压、抗氧化、增强溶纤维蛋白活性、抑制血小板凝集和降血糖的作用。作者发明了一种半合成方法制备了大量纯大蒜的活性成分蒜素 (ａｌｌｉｃｉｎ) ,用果糖饲养ＳＤ大鼠诱导出现高胰岛素、高血脂和高血压的症状 ,以考察在此模型上蒜素对大鼠血压、甘油三酯和胰岛素水平的影响 ,并将研究结果与抗高血压药依那普利 (ｅｎａｌａｐｒｉｌ)进行比较。将三组雄性ＳＤ大鼠喂食果糖食物 5周 ,2周后一组动物 (10只 )仅喂食果糖作为对照组 ,一…     

大蒜新素对实验性急性脑缺血的保护作用

大蒜新素对实验性急性脑缺血的保护作用马晓红１刘天培（南京医科大学药理学教研室，南京２１００２９）大蒜新素（ａｌｉｔｒｉｄｉ，Ａｌ）为葱科植物大蒜中的有效成分，已发现其有降压，降血脂，抗动脉粥样硬化，抗血小板聚集及抗心肌缺血等作用［１，２］．临床上有关...     

Efficacy of gut lavage,hemodialysis, and hemoperfusion in the therapy of paraquat or diquat intoxication

Clinical and in vitro investigations were carried out to test the efficacy of gut lavage, hemodialysis, and hemoperfusion in the treatment of poisoning with paraquat or diquat. In a patient suffering from diquat intoxication 130 times more diquat was removed by gut lavage 30 h after ingestion than was removed by complete aspiration of the gastric contents.Determination of in vitro clearances for paraquat and diquat by hemodialysis showed that, at serum concentrations of 1–2 ppm, such as are frequently encountered in poisoning in man, toxicologically relevant quantities of herbicide cannot be removed from the body. At a concentration of 20 ppm, on the other hand, hemodialysis proved to be effective, the clearance being 70 ml/min at a blood flow rate of 100 ml/min. The efficacy of hemoperfusion with coated activated charcoal was on the whole better. Especially at concentrations around 1–2 ppm, the clearance values for hemoperfusion were some 5–7 times higher than those for hemodialysis.In a patient suffering from paraquat poisoning, both hemodialysis as well as hemoperfusion were carried out. The in vitro results could be confirmed: At serum concentrations of paraquat less than 1 ppm no clearance could be obtained by hemodialysis while by hemoperfusion with activated charcoal quite high clearance values were measured and the serum level dropped down to zero.

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Zusammenfassung Klinische Untersuchungen und Laboratoriumsversuche wurden durchgeführt, um die Wirksamkeit von Darmspülung, Hämodialyse und Hämoperfusion bei Paraquat- und Deiquat-Vergiftungen zu prüfen.Bei einem Patienten wurde 30 Std nach Deiquat-Aufnahme durch Darmspülung 130mal mehr Deiquat entfernt als durch vollständige Aspiration des Mageninhaltes. In vitro-Versuche ergaben, daß bei Blutserumkonzentrationen von 1–2 ppm, die bei Vergiftungen oft gemessen werden, durch Hämodialyse keine toxikologisch relevanten Paraquat- oder Deiquat-Mengen entfernt werden können. Dagegen erwies sich die Hämodialyse bei 20 ppm und einer Blutumlaufgeschwindigkeit von 100 ml/min mit einer Clearance von 70 ml/min als wirksam. Die Hämoperfusion mit beschicheter Aktivkohle war in diesen Versuchen aber eindeutig überlegen, denn insbesondere bei Konzentrationen um 1–2 ppm waren die Clearance-Werte 5–7mal höher als bei der Hämodialyse.Die in vitro-Ergebnisse wurden bei einem Patienten mit einer Paraquat-Vergiftung bestätigt: Bei Konzentrationen unter 1 ppm war die Hämodialyse wirkungslos, während durch Hämoperfusion relativ hohe Clearance-Werte erreicht wurden, so daß der Serumspiegel rasch unter die Nachweisgrenze abfiel.

     

In vitro studies on sterically stabilized liposomes (SL) as enzyme carriers in organophosphorus (OP) antagonism

This study describes a new approach for organophosphorous (OP) antidotal treatment by encapsulating an OP hydrolyzing enzyme, OPA anhydrolase (OPAA), within sterically stabilized liposomes. The recombinant OPAA enzyme was derived from Alteromonas strain JD6. It has broad substrate specificity to a wide range of OP compounds: DFP and the nerve agents, soman and sarin. Liposomes encapsulating OPAA (SL)* were made by mechanical dispersion method. Hydrolysis of DFP by (SL)* was measured by following an increase of fluoride ion concentration using a fluoride ion selective electrode. OPAA entrapped in the carrier liposomes rapidly hydrolyze DFP, with the rate of DFP hydrolysis directly proportional to the amount of (SL)* added to the solution. Liposomal carriers containing no enzyme did not hydrolyze DFP. The reaction was linear and the rate of hydrolysis was first order in the substrate. This enzyme carrier system serves as a biodegradable protective environment for the recombinant OP-metabolizing enzyme, OPAA, resulting in prolongation of enzymatic concentration in the body. These studies suggest that the protection of OP intoxication can be strikingly enhanced by adding OPAA encapsulated within (SL)* to pralidoxime and atropine.     

Aquatic Insects and Trace Metals: Bioavailability,Bioaccumulation, and Toxicity

Abstract

The uptake of metals from food and water sources by insects is thought to be additive. For a given metal, the proportions taken up from water and food will depend both on the bioavailable concentration of the metal associated with each source and the mechanism and rate by which the metal enters the insect. Attempts to correlate insect trace metal concentrations with the trophic level of insects should be made with a knowledge of the feeding relationships of the individual taxa concerned. Pathways for the uptake of essential metals, such as copper and zinc, exist at the cellular level, and other nonessential metals, such as cadmium, also appear to enter via these routes. Within cells, trace metals can be bound to proteins or stored in granules. The internal distribution of metals among body tissues is very heterogeneous, and distribution patterns tend to be both metal and taxon specific. Trace metals associated with insects can be both bound on the surface of their chitinous exoskeleton and incorporated into body tissues. The quantities of trace meals accumulated by an individual reflect the net balance between the rate of metal influx from both dissolved and particulate sources and the rate of metal efflux from the organism. The toxicity of metals has been demonstrated at all levels of biological organization: cell, tissue, individual, population, and community. Much of the literature pertaining to the toxic effects of metals on aquatic insects is based on laboratory observations and, as such, it is difficult to extrapolate the data to insects in nature. The few experimental studies in nature suggest that trace metal contaminants can affect both the distribution and the abundance of aquatic insects. Insects have a largely unexploited potential as biomonitors of metal contamination in nature. A better understanding of the physico-chemical and biological mechanisms mediating trace metal bioavailability and exchange will facilitate the development of general predictive models relating trace metal concentrations in insects to those in their environment. Such models will facilitate the use of insects as contaminant biomonitors.     

Alzheimer’s disease – current trends in basic and clinical research. Highlights from the 16th ECNP

Advances in the molecular biological knowledge of neuronal nicotinic acetylcholine receptors (nAChRs) have led to a growing interest by the pharmaceutical industry in the development of novel compounds that selectively modulate nAChR function. The ability of (-)-nicotine, an activator of nAChRs, to enhance attentional aspects of cognition in animals and humans, to exert neuroprotective and anxiolytic-like effects, and presumably to mediate the negative correlation between smoking and Alzheimer's (and Parkinson's) Disease, has focused interest on the potential therapeutic utility of modulators of nAChR function for treatment of some of the deficits associated with these progressive, neurodegenerative conditions. Numerous compounds are known which activate nAChRs and which might serve as lead compounds toward the development of such agents. The pharmacologic diversity of neuronal nAChR subtypes suggests the possibility of developing selective compounds which would have more favourable side-effect profiles than existing agents. This broader class of agents, collectively called cholinergic channel modulators (ChCMs), is anticipated to encompass compounds which would have more favourable side-effect profiles than existing agents, which generally exhibit low selectivity. This selectivity may be achieved by preferentially activating some subtypes of nAChRs (i.e., Cholinergic Channel Activators, ChCAs) or inhibiting the function of other subtypes (Cholinergic Channel Inhibitors, ChCIs). An overview of the biology of nAChRs and the rationale for the use of ChCMs for the treatment of dementia related to neurodegenerative diseases are presented, followed by a discussion of lead compounds and compounds under consideration for clinical evaluation.     

Steroidal sapogenin contents in some domestic plants

In order to find out the values of the steroid resources for the future use. the compositions and contents of steroidal sapogenins from 13 domestic plants have been investigated. As a result,Dioscorea nipponica, D. quinqueloba andSmilax china were found to have large amount of diosgenin. And pennogenin inTrillium kamtschaticum andParis verticillata, yuccagenin inAllium fistulosum, hecogenin inAgave americana and neochlorogenin inSolanum nigum were appeared to be major steroidal sapogenins.