右美托咪定对七氟醚所致幼鼠学习障碍和抑制突触蛋白表达的影响

目的探讨右美托咪定对七氟醚所致幼鼠长期学习记忆障碍和对海马突触蛋白表达的影响。方法将7日龄SD幼鼠随机分为对照组,七氟醚组,右美托咪定组和七氟醚＋右美托咪定组。麻醉后1d和7d采用west—erablot和RT—PCR测定海马内突触素、突触后致密物-95（PSD-95）和哺乳动物雷帕霉素靶蛋白（mammalian target of rapamycin,mTOR）蛋白和mRNA表达。5周后行Morris水迷宫测试。结果七氟醚麻醉后大鼠学习速度下降;七氟醚和右美托咪定均抑制幼鼠海马内突触素和PSD-95的蛋白表达和mRNA水平,右关托咪定显著减轻七氟醚的抑制作用。三种药物组合均显著抑制幼鼠海马内磷酸化mTOR（p-mTOR）蛋白和mTOR mRNA水平。结论右美托咪定可以减轻七氟醚所致幼鼠长期学习记忆障碍和对海马突触蛋白的抑制作用,这种保护作用并不是通过p-mTOR途径发挥作用的。     

松果体素抑制大鼠海马神经元甘氨酸激活的全细胞电流

目的研究松果体素对培养的大鼠海马神经元甘氨酸激活的全细胞电流(Igly)的调控。方法在培养的大鼠海马神经元上,采用全细胞膜片钳技术,研究松果体素对甘氨酸激活的全细胞电流的调控。结果松果体素以浓度依赖的方式可逆地抑制Igly,并且这种抑制作用是非竞争性的,松果体素的抑制作用没有特异的亚基选择性。结论松果体素能以非竞争的方式直接抑制甘氨酸受体介导的电流,这种抑制作用可能对海马区域神经网络的兴奋性产生影响。     

山奈酚对急性短暂缺氧时大鼠海马CA1神经元电压依赖性钾通道的作用

目的研究山奈酚对正常和急性短暂缺氧时大鼠海马CA1锥体神经元电压依赖性钾通道的作用.方法急性分离大鼠海马CA1区锥体神经元,采用全细胞记录,用含有氰化钾(KCN)60μmol·L-1的标准外液灌流模拟细胞缺氧,观察山奈酚对正常和缺氧时海马CA1区神经元电压依赖性钾通道的作用.结果山奈酚对正常和缺氧时海马CA1神经元电压依赖性K 电流有明显的抑制作用,可同时抑制瞬时外向型钾电流(IA)和延迟整流性钾电流(Ik),具有浓度依赖和电压依赖性;山奈酚对IA的半数抑制浓度(IC50)约为50μmol·L-1,对IK的IC50约为80μmol·L-1.结论山奈酚对正常和缺氧时大鼠海马CA1神经元电压依赖性钾通道有抑制作用,其对钾通道的抑制作用可能参与脑缺血保护.     

铅对小鼠海马[Ca2+]的影响及L型钙通道的作用

目的　探讨铅对分离的小鼠海马细胞内游离钙的影响及其及L型钙通道的作用。方法　采用低浓度胰蛋白酶消化法分离小鼠海马细胞 ,并以莹光指标剂 (Fura 2 )作Ca2 荧光探针 ,用双波长荧光法测定海马细胞 [Ca2 ] i。结果　铅可致分离的小鼠海马细胞 [Ca2 ] i 升高 [由静息时的 (2 0 3 4± 10 86)nmol L升至 (4 2 3 3± 19 2 6)nmol L] ,而不论胞外是否有钙 ;铅可抑制钾诱发海马细胞 [Ca2 ] i 升高 ,尼莫地平可加强这种抑制作用 ,而BayK864 4则可部分消除这种抑制作用。结论　铅可致分离的小鼠海马细胞 [Ca2 ] i 升高作用与胞内钙库释放有关 ;铅的抑制钾诱发海马细胞 [Ca2 ] i 升高作用与其抑制L型钙通道有关。     

SC1001Na对马桑内酯点燃大鼠海马脑片CA1区锥体细胞群体锋电…

作者用离体海马脑片技术，从细胞水平观察及比较了ｓｃ１００１Ｎａ对马桑内酯点燃大鼠海马脑片ＣＡ１区群体锋电位（ＰＳ）的影响。结果表明：不同浓度的ｓｃ１００１Ｎａ和安定对ＰＳ均有抑制作用，其抑制作用在对照组两组比较有显著差异（Ｐ〈０．００１），而在点燃组无显著差异（Ｐ〉０．０５）。提示ｓｃ１００１Ｎａ具有较强的中枢抑制作用。但其作用机制可能与安定不同。     

SC_（100）Na对马桑内酯点燃大鼠海马脑片CA_1区锥体细胞群体锋电位的影响

作者用离体海马脑片技术，从细胞水平观察及比较了ＳＣ_（１００）Ｎa对马桑内酯点燃大鼠海马脑片ＣＡ_１区群体锋电位（ＰＳ）的影响。结果表明：不同浓度的SC_(1001)Ｎａ和安定对ＰＳ均有抑制作用，其抑制作用在对照组两组比较有显著差异（ｐ＜０．００１），而在点燃组无显著差异（ｐ＞０．０５）。提示ＳＣ_（１００）Ｎa具有较强的中枢抑制作用。但其作用机制可能与安定不同。     

咪唑安定临床治疗浓度对海马神经元钠离子通道的作用

目的 :采用大鼠海马神经元作为研究对象 ,研究咪唑安定对神经元钠离子通道的影响 ,以探讨其临床遗忘作用的可能机制。方法 :在急性分离的大鼠海马锥体神经元上 ,利用全细胞膜片钳技术 ,记录钠离子通道的电流 ,研究咪唑安定对钠离子通道电流幅度和激活特性的影响。结果 :咪唑安定对海马钠离子通道电流具有可逆性抑制作用 ,0 .1和1 0 μmol·L- 1 的咪唑安定对钠离子通道分别抑制了(7.95± 7.46) %和 (2 5 .3 7± 8.3 1 ) % (P <0 .0 1 )。1 0 μmol·L- 1 的咪唑安定还可使钠离子通道的激活曲线右移。结论 :咪唑安定对海马神经元上的钠离子电流有较弱程度的抑制作用 ,但可能不是其主要的临床作用机制     

远志对Aβ25—35诱导AD模型大鼠海马区NF—κB活化研究

目的：观察远志对双侧海马注射Aβ25—35建立的AD模型大鼠海马区NF—κB p65的活化、P-IκB、IκB表达的影响,从NF—κB信号转导通路调控机制探讨远志对AD可能的防治作用途径。方法：将96只大鼠随机分为正常对照组,假手术组,模型组,远志低、中、高剂量组共6组,每组16只。采用双侧海马注射β淀粉样多肽25—35片断（Aβ25—35）制作大鼠AD模型;连续给药4周后采用免疫荧光法检测各组大鼠NF—κB p65活化;免疫组化法观察P—IκB、IκB在大鼠海马区的表达。结果：远志能抑制AD模型大鼠海马区NF—κB p65活化。结论：远志能够抑制AD模型大鼠海马区NFκB p65活化,这种作用主要是通过抑制IκBa磷酸化降解而不是通过刺激IκBa蛋白合成增加来实现的。     

地昔帕明对大鼠海马神经元钾电流的影响

目的研究地昔帕明(desipramine,DMI)对大鼠海马神经元钾电流的影响,初步探讨其抗抑郁的离子通道机制。方法酶解法急性分离单个大鼠海马神经元,应用全细胞膜片钳技术记录DMI对海马神经元钾电流的影响。结果不同浓度DMI均可抑制海马神经元延迟整流钾电流(IK)和瞬时外向钾电流(IA)的影响,其中,100μmol·L-1DMI明显下移IK和IA电流电压曲线,同时,DMI对IK的抑制率明显高于IA。结论DMI对大鼠海马神经元外向钾电流具有明显的抑制作用,提示这可能是其神经保护的机制之一。     

内源性腺苷作为海马乙酰胆碱释放的调节剂

近十年的研究证明,腺苷及其有关的嘌呤核苷对外周和中枢神经系统的神经元活动有调节作用,并且是通过特异性受体而发挥作用,海马神经细胞对腺苷及其类似物的抑制作用尤为敏感,但对其机理的解释尚有分歧。作者通过实验证明,内源性腺苷通过A_1-(R_1-)受体在胆碱能神经末梢抑制海马乙酰胆碱(ACh)的释     

Echinacea and its alkylamides: Effects on the influenza A-induced secretion of cytokines,chemokines, and PGE2 from RAW 264.7 macrophage-like cells

The goal of this study was to determine whether extracts and isolated alkylamides from Echinacea purpurea would be useful for prevention of the inflammatory response that accompanies infections with H1N1 influenza A. Seventeen extracts and 4 alkylamides were tested for the ability to inhibit production of cytokines, chemokines, and PGE₂ from RAW 264.7 macrophage-like cells infected with the H1N1 influenza A strain PR/8/34. The alkylamides undeca-2Z,4E-diene-8,10-diynic acid isobutylamide, dodeca-2E,4E,8Z,10E/Z-tetraenoic acid isobutylamide, dodeca-2E,4E-dienoic acid isobutylamide, and undeca-2E-ene-8,10-diynoic acid isobutylamide suppressed production of TNF-α and PGE₂ from infected cells. Dodeca-2E,4E-dienoic acid isobutylamide was especially effective at inhibiting production of these mediators and also strongly inhibited production of G-CSF, CCL2/MCP-1, CCL3/MIP-1α and CCL5/RANTES. In contrast, the ethanol extracts (75%), which were prepared from dormant roots of E. purpurea grown in different locations throughout North Carolina, displayed a range of effects from suppression to stimulation of mediator production. Precipitation of the extracts with ethanol removed the stimulatory activity, however, even after precipitation; many of the extracts did not display any suppressive activity. Analysis of the extracts revealed slight variations in concentration of alkylamides, caftaric acid, and cichoric acid, but the activity of the extracts did not strongly correlate with concentrations of these compounds. Our in vitro experiments suggest that E. purpurea extracts have the potential for use in alleviating the symptoms and pathology associated with infections with influenza A; however, further study will be necessary to define procedures necessary to unmask the alkylamide activity in crude extracts.     

Comparison of antioxidant activities between salvianolic acid B and Ginkgo biloba extract （EGb 761）

AIM: To investigate and compare the antioxidant activities of salvianolic acid B (SalB) and Ginkgo biloba extract (EGb 761) in aqueous solution, rat microsomes and the cellular system. METHODS: Superoxide anion (O2-.) was generated using xanthine/xanthine oxidase system and phenazine methosulate/NADH system, and the effects of SalB and EGb 761 on the generation of O2-.were achieved by spectrophotometric measurement of the product formed on reduction of nitro blue tetrazolium. Two different methods were used to assess the scavenging effects of the extracts on hydroxyl radical (. OH): HPLC method was used for quantitation of . OH by oxy-radical trapping of 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) to form DMPO-OH adducts in Fe2+-EDTA-H2O2 system. To confirm the HPLC data, .OH was also measured by spectrophotometry using a commercial detection kit. The anti-lipid peroxidation effects of the extracts in microsomes of rat brain, liver and kidney induced by ascorbate-NADPH were determined by thiobarbituric acid (TBA) method. The protective effects of the extracts on peroxide hydrogen (H2O2)-induced oxidative damage in SH-SY5Y cells were investigated by assessing cell viability assay, the level of lipid peroxidation, and the lactate dehydrogenase(LDH) release. RESULTS: Both SalB and EGb 761 were able to scavenge O2-. and . OH, inhibit lipid peroxidation of microsomes, and protect SH-SY5Y cells against H2O2-induced oxidative damage. However, the concentration of SalB was far lower than that of EGb 761 when a similar effect was obtained. CONCLUSION: The antioxidant efficiency of SalB was greater than that of EGb 761. These results suggest that SalB, like EGb 761, has promising potential in treating oxidative damage-derived neurodegenerative disorders.     

Antimycobacterial brominated metabolites from two species of marine sponges

A screening of 500 crude extracts of marine invertebrates against the growth of Mycobacterium tuberculosis H37Rv yielded MeOH extracts of the sponges Aplysina cauliformis and Pachychalina sp. with significant activity. Further bioassay-guided fractionation of both crude extracts led to the isolation of four bromine-containing metabolites. The known (+)-fistularin-3 (1) and 11-deoxyfistularin-3 (2), and the new compound 2-(3-amino-2,4-dibromo-6-hydroxyphenyl)acetic acid (3) were isolated from the sponge A. cauliformis, while the new bromotyrosine-derived 3-(3,5-dibromo-4-methoxyphenyl)-2-methoxy- N-methylpropan-1-ammonium (4) was isolated from Pachychalina sp. Compound 4 exhibited weak antimycobacterial activity while compounds 1-3 displayed activity against Mycobacterium tuberculosis H37Rv, with MICs of 7.1, 7.3 and 49 microM, respectively. Compounds 1 and 2 also exhibited low cytotoxicity against J744 macrophages, indicating that both 1 and 2 are interesting leads for the development of new anti-tuberculosis agents.     

台湾虫草子实体提取物高分辨液质联用分析

目的分析天然台湾虫草子实体的活性成分。方法用高分辨液质联用分析法,对其甲醇提取物及二氯甲烷和乙酸乙酯混溶剂提取物进行了成分分析。结果甲醇提取物中主要含有甘露醇、醌茜素、油酸和一种可能为羰基氨基酸类的化合物。对二氯甲烷和乙酸乙酯混溶剂提取物的分析发现其主要成分可能为醌茜素、麦角甾醇、硬脂酸、软脂酸、油酸、亚油酸、Ternatin、C12H 30N8O8、C14H32N4O4、C19H38N2O6以及一种挥发性强或难离子化的极性小分子化合物,上述化合物都是首次在台湾虫草子实体中发现,其中化合物C12H 30N8O8、C14H32N4O4和C19H38N2O6为3种新化合物。结论通过本研究可以为进一步研究台湾虫草的活性成分及开发其药用价值打下坚实的基础。     

Effect of Baccharis dracunculifolia D.C. (Asteraceae) extracts and its isolated compounds on macrophage activation

Baccharis dracunculifolia D.C. (Asteraceae), a shrub which grows wild in Brazil, is the main botanical source of Brazilian green propolis. Since Brazilian propolis shows an immunomodulatory activity, the goal of this work was to evaluate the action of B. dracunculifolia extracts and some of its isolated compounds on reactive oxygen intermediate (H(2)O(2)) production by macrophages obtained from male BALB/c mice. The results showed that the leaf (Bd-L) (25, 50, and 100 microg mL(-1)), leaf rinse (Bd-LR) (25 microg mL(-1)), and the root (Bd-R) (25 microg mL(-1)) extracts enhanced H2O2 release by macrophages. A phytochemical study of the root and leaves of B. dracunculifolia was carried out. The chromatographic fractionation of Bd-R, using several techniques, afforded the isolation of baccharis oxide (1), friedelanol (2), viscidone (11), 11-hydroxy-10,11-dihydro-euparin (12), and 6hydroxy-tremetona (13), while Bd-LR gave the following isolated compounds: baccharis oxide (1), friedelanol (2), isosakuranetin (3), aromadendrin-4'-methyl ether (4), dihydrocumaric acid (5), baccharin (6), hautriwaic acid lactone (7), hautriwaic acid acetate (8), drupanin (9), and cumaric acid (10). Among the isolated compounds, baccharis oxide (1) and friedelanol (2) increased H2O2 production at a concentration of 100 microM. This is the first time that the presence of compounds 7, 8, 12, and 13 in B. dracunculifolia has been reported. Based on these results it is suggested that the crude extracts and some isolated compounds from B. dracunculifolia display an immunomodulatory action.     

Screening of antioxidants from medicinal plants for cardioprotective effect against doxorubicin toxicity

Doxorubicin is an important and effective anticancer drug widely used for the treatment of various types of cancer but its clinical use is limited by dose-dependent cardiotoxicity. Elevated tissue levels of cellular superoxide anion/oxidative stress are a mechanism by which doxorubicin-induced cardiotoxicity. Selected medicinal plant extracts were tested for their antioxidant capacity and cardioprotective effect against doxorubicin-induced cardiotoxicity. The cardiac myoblasts H9c2 were incubated with the antioxidants ascorbic acid, trolox, N-acetylcysteine or selected medicinal plant extracts including; 1) ethanolic extracts from Curcuma longa L-EtOH Phyllanthus emblica L-EtOH, and Piper rostratum Roxb-EtOH; and 2) water extracts from Curcuma longa L-H2O and Morus alba L-H2O. The cardioprotective effects of these extracts were evaluated by crystal violet cytotoxicity assay. IC50s of doxorubicin were compared in the presence or absence of ascorbic acids, trolox, N-acetylcysteine or plant extracts. Morus alba L-H2O showed the highest antioxidant properties evaluated by ferric reducing/antioxidant power assay. Ascorbic acid and N-acetylcysteine had modest effects on the protection of doxorubicin-induced cytotoxicity while trolox showed insignificant protective effect. All plant extracts protected cardiac toxicity at different degrees except that Curcuma longa L-EtOH had no protective effect. Phyllanthus emblica-EtOH (100 microg/ml) showed the highest cardioprotective effect (approximately 12-fold doxorubicin IC50 increase). The data demonstrate that antioxidants from natural sources may be useful in the protection of cardiotoxicity in patients who receive doxorubicin.     

Antimutagenic, antioxidant and free radical scavenging activity of ethyl acetate extracts from white, yellow and red onions.

The beneficial effects of red, yellow and white onion extracts have been assessed by antioxidant activity and antimutagenic activity. And the effects compared to BHT and ascorbic acid. Total phenolic compounds and flavonoids in onion extracts were determined. Yellow onion extract had more organic acid and free sugar than those detected in the white and red onion extract. The scavenging activity of DPPH radical and H(2)O(2) were increased depending on the concentration. The antioxidant activities using beta-carotene-linoleate system and reducing power were increased but the effect was small to that of BHT and ascorbic acid. After digested, extracts showed antimutagenic activities, and it seems that they inhibit the mutagenicity for digesting. This study demonstrated that the antimutagenicities and antioxidant properties of ethyl acetate extract against mutagens were related to their phenols and flavonoids, which are heat stable and losses digestive juices are relatively low.     

NMR-spectroscopy-based metabonomic approach to the analysis of Bay41-4109, a novel anti-HBV compound, induced hepatotoxicity in rats

An integrated metabonomics study using high-resolution (1)H nuclear magnetic resonance (NMR) spectroscopy has been applied to investigate the biochemical composition of urine, serum, liver tissue aqueous extracts (acetonitrile/water) and liver tissue lipidic extracts (chloroform/methanol) obtained from control and Bay41-4109 treated rats (10, 50, 400mg.kg(-1).d(-1) for 5 days, i.g.). Principal components analysis was used to visualize similarities and differences in biochemical profiles. The results showed the effects induced by Bay41-4109 at 400mg.kg(-1).d(-1) are different from those induced at 10, 50mg.kg(-1).d(-1). The biochemical profiles of 400mg.kg(-1).d(-1) group might reflect the hepatotoxicity of Bay41-4109 more exactly. The elevation in the level of 3-HB, lactate, 2-hydroxy-acetol and d-glucose was found in the urine, and the levels of VLDL/LDL(CH(2))(n), VLDL/LDL-CH(3), 2-oxo-3-methyl-n-valerate, 3-HB, lactate, acetate, taurine, 2-hydroxy-isovalerate in serum were increased significantly in 400mg.kg(-1).d(-1) group. The predominant changes identified in liver tissue aqueous extracts included an increase in the signal intensities of lactate, 3-amino-isovalerate, pyruvate, choline, trimethylamine-N-oxide (TMAO) and a reduction in the intensities of taurine, hippurate and d-glucose. In liver tissue chloroform/methanol extracts, there was a remarkably increase in many of the lipid signals including the triglyceride terminal methyl, methylene groups, and CH(2)CO, N(+)(CH(3))(3), CH(2)OPO(2), CH(2)OCOR. These observations all provide evidence that fatty acid metabolism disorder and mitochondrial inability might contribute to the hepatotoxicity of Bay41-4109. The application of (1)H NMR spectroscopy to an array of biological samples comprising urine, serum and liver tissue extracts yields new insight into the hepatotoxicity of xenobiotics.     

基于NF-κB信号通路筛选产抗炎活性次级代谢产物的红树林真菌

摘要：目的 以福建漳江口红树林沉积物来源真菌为对象,筛选产抗炎活性次级代谢产物的红树林真菌。方法 将pNFκB-luc 与pRL-SV40-C报告基因质粒共转染Raw264.7细胞,脂多糖(LPS)刺激该细胞建立体外炎症模型,构建双荧光素酶报告基因筛选体 系,对福建漳江口红树林沉积物来源真菌的发酵粗提物进行抗炎活性筛选;CCK-8法检测粗提物对Raw264.7细胞活力影响;光学显 微镜观察粗提物对LPS刺激的Raw264.7细胞分化作用。结果 从102株红树林沉积物来源真菌中获得5株阳性菌株,其发酵粗提物可 明显抑制LPS诱导的Raw264.7细胞中NF-κB信号通路活化,菌株编号分别为H788、H1458、H515、XT20-8和T2-3'。结论 5株红树 林沉积物来源真菌产生的次级代谢产物可通过抑制NF-κB信号通路发挥抗炎作用,其活性成分值得开展进一步化学研究。     

Chemical and pharmacological evaluation of Hypericum perforatum extracts

AIM: To determine the concentrations of chemical characteristic to extracts of leaves and flowers of Hypericum perforatum (St John's wort) in a number of selected samples and, following chemical characterization, to investigate the effects of these extracts on several pharmacological properties including effects of the extracts on inhibition of 5-hydroxytryptamine (5-HT) uptake and on antioxidant properties. METHODS: The samples were analyzed for the presence of characteristic chemicals by high performance liquid chromatography (HPLC) directly coupled to ultraviolet wavelength absorbance and positive or negative mode electrospray mass spectrometric detection. The effects of extracts on 5-HT uptake were determined by quantifying 3H-5-HT incorporation into rat hippocampal prisms. Estimates of effects of extracts on free radical scavenging capacity were made using a dynamic assay based on the ability of compounds to prevent the initiation of a colored reaction produced by the horseradish peroxidase catalyzed formation of hydroxyl free radicals from hydrogen peroxide using 2',2'-azinobis (3-ethylbenzthiazoline-6-sulfonic acid) as the color indicator. RESULTS: The chemical profile of a number of extracts were determined and found to differ substantially from each other. Inhibition of 5-HT uptake was found to correlate with hyperforin content and free radical scavenging capacity was found to correlate with the content of several flavonoids including quercetin and hyperoside. CONCLUSION: Standardized extracts of H perforatum varied substantially in the concentration of several characteristic chemicals. The correlation between pharmacological activity and certain characteristic chemicals found in these extracts indicates that the medicinal benefit derived from selected extracts will vary considerably depending on their chemical composition.