S-甲基异硫脲对大鼠门脉高压症食管静脉曲张的影响

目的观察诱导型一氧化氮合酶抑制剂SMT对大鼠门脉高压症食管静脉曲张的影响。方法健康雄性SD大鼠60只随机分为5组,假手术组、模型组、低剂量组、中剂量组和高剂量组。假手术组仅分离门静脉、左肾上腺静脉关腹,其余组门脉缩窄两步法加左肾上腺静脉结扎,建立门脉高压症食管静脉曲张模型。假手术组与模型组手术后给予腹腔注射生理盐水,其余3组手术后给予腹腔注射不同浓度SMT。手术后21 d,检测大鼠门脉血中TNOS、iNOS的活性及NO的浓度,免疫组化CD34标记食管血管内皮,测量每组大鼠食管横切面黏膜下血管的数目、面积。结果模型组大鼠门脉血中TNOS活性与iNOS活性以及NO浓度和食管黏膜下血管数目,血管平均截面积,血管总面积均较假手术组显著升高（P〈0.01）。中、高剂量组大鼠门脉血中TNOS活性与iNOS活性以及NO浓度和食管黏膜下血管的数目、血管平均面积、血管总面积较模型组均显著下调（P≤0.01）。结论大鼠门脉高压食管静脉曲张的发病机制中有NO参与,门脉缩窄型门脉高压食管静脉曲张病中NO主要由iNOS生成,SMT对大鼠门脉高压食管静脉曲张可能具有一定保护作用。     

二月桂酸二丁基锡对大鼠肝脏NO含量及GSH-PX活性的影响

目的探讨二月桂酸二丁基锡（DBTD）对大鼠肝脏NO含量及GSH-PX活性的影响。方法NO试剂盒测定NO含量;GSH-PX试剂盒测定GSH-PX活性。结果NO含量各染毒组与对照组比较均有显著性差异（P〈0.05）;GSH-PX的活性随染毒剂量的升高而降低,与对照组比较均有显著性差异（P〈0.05）。结论DBTD可使肝组织NO含量增高;GSH-PX活性下降。     

低氧对高原鼠兔和大鼠血液NO 与ET-1的影响

将Wistar大鼠暴露于3 780 m低氧环境,分别于24 h、2 wk及3 wk后采用酶联免疫法和硝酸还原酶法测定血液中的ET~(-1)和NO的含量,计算NO/ET~(-1)值,并与高原鼠兔比较,探讨低氧条件下大鼠与高原鼠兔血液中NO与ET~(-1)含量的变化趋势。结果表明,低氧24 h后,大鼠血液中NO和ET~(-1)的含量显著高于同海拔的高原鼠兔(P<0·01),而NO/ET~(-1)值无显著差异(P>0·05)。随着大鼠在高海拔停留时间的延长,血液中NO含量呈减少趋势,而ET~(-1)则有上升趋势,二者呈显著的负相关(r2=0·2416,P<0·01)。高原鼠兔NO/ET~(-1)值约为大鼠低氧2 wk和3 wk的2倍(P<0·01)。说明不同低氧暴露时间,高原鼠兔和大鼠的NO、ET~(-1)及NO/ET~(-1)值有显著差异,提示NO/ET~(-1)值可以作为有机体是否适应高原低氧环境的一个指标。     

外源NO对南方红豆杉幼苗光合色素及抗氧化酶的影响

以4年生南方红豆杉幼苗为实验材料,通过对南方红豆杉幼苗喷施不同浓度外源一氧化氮（NO）供体硝普钠溶液（0、0.01、0.1、0.5和1 mmol·L^-1SNP）,测定光合色素含量、抗氧化酶活性、丙二醛（MDA）含量和过氧化氢（H₂O₂）含量等生理指标,以探讨不同浓度外源NO对南方红豆杉叶片光合色素和抗氧化酶的影响。结果表明：喷施低浓度（0.01、0.1 mmol·L^-1）SNP可显著提高南方红豆杉叶片的叶绿素a、叶绿素b、类胡萝卜素和总叶绿素含量,增加叶绿素a/b的比值,而喷施高浓度（0.5、1 mmol·L^-1）SNP降低了叶片的光合色素含量。随着外源NO供体浓度的增加,叶片过氧化氢酶(CAT)活性显著增加,过氧化物酶(POD)活性先增加后降低。此外,处理前期,低浓度SNP处理明显提高了抗坏血酸过氧化物酶(APX)活性,而高浓度SNP处理显著降低了APX活性,处理后期APX活性随SNP浓度的增加而显著下降。喷施低浓度SNP可有效提高超氧化物歧化酶(SOD)活性和增加可溶性蛋白含量,降低MDA和H₂O₂的含量,而喷施高浓度SNP显著增加了MDA和H₂O₂的含量。因此,低浓度的SNP（<0.5 mmol·L^-1）处理南方红豆杉幼苗,可增加其叶绿素含量,提高抗氧化酶活性,降低MDA和H₂O₂的含量,而高浓度的SNP（≥0.5 mmol·L^-1）处理会降低叶绿素含量,提高H₂O₂含量,增加细胞膜质过氧化程度,从而对南方红豆杉幼苗造成一定伤害。     

一氧化氮的生物学作用简介

一氧化氮的生物学作用简介冯群先沈士弼（南京中医药大学生化教研室,南京２１００２９）（南京医科大学生化教研室）关键词一氧化氮（ＮＯ）,生物学作用一氧化氮（ＮＯ）是无色、透明的气体,一旦与空气接触即显棕褐色。汽车排出的废气及吸烟者的烟雾中均含有ＮＯ,它能...     

一氧化氮合酶的若干研究进展

一氧化氮合酶(NOS)是一氧化氮(NO)生物学与医学研究的重要内容.近年来,对NOS酶本质及其生化与分子生物学特性甚至某些分子遗传学方面的认识都在迅速发展和深化.研究表明,干预NOS-NO途径的某些环节,如酶激活、NO合成、释放与转运甚至有关酶的编码基因及其表达,将为某些临床问题的解决提供新的思路和手段．     

牛膝多糖对小鼠腹腔巨噬细胞的细胞毒作用影响及机制

研究牛膝多糖(ABPS)对巨噬细胞细胞毒作用的影响及机制。以200 mg/L浓度的ABPS体外刺激小鼠腹腔来源巨噬细胞,采用MTT法检测细胞毒作用,Griess试剂盒检测NO的生成,Real-Time PCR和Western blot分别检测i NOS mRNA和蛋白的表达。结果显示,浓度为200 mg/L的ABPS对巨噬细胞细胞毒作用和NO表达有显著的促进作用,对i NOS mRNA和蛋白表达均有明显的促进作用。研究结果提示ABPS可能通过增强细胞内i NOS表达,促进NO生成和释放,从而促进巨噬细胞细胞毒作用。     

一氧化氮合酶与脓毒症的研究进展

脓毒症在外科临床工作中较常见,治疗相当困难;本文主要概述了一氧化氮合酶的基因定位、结构特点以及一氧化氮合酶与脓毒症的关系,进一步说明由一氧化氮合酶介导的一氧化氮生成与脓毒症关系密切,而选择性一氧化氮合酶抑制剂在脓毒症各阶段恰当的应用可能是有效治疗脓毒症、降低病死率的一个重要途径,也将成为今后研究的热点。     

野生仙人掌多糖对肺鳞癌细胞SK-MES-1 生长的抑制作用

目的:探讨仙人掌多糖对体外肺鳞癌细胞(SK-MES-1)生长抑制作用。方法:体外培养SK-MES-1细胞,四甲基偶氮唑盐(MTT)法观察野生仙人掌多糖对其生长的抑制,计算最低抑制浓度及抑制率;观察不同浓度多糖对细胞形态的影响;SDS-PAGE凝胶电泳简析不同组别蛋白质表达的差异。结果:野生仙人掌多糖24 h和48 h对肿瘤细胞的最低抑制浓度和抑制率分别为0.0625 mg/ml.34.06%和0.0625 mg/ml 35.37%;不同组间蛋白质表达有差异。结论:野生仙人掌多糖对SK-MES-1肺鳞癌细胞有抑制作用。     

Two novel C29-5beta-sterols from the stems of Opuntia dillenii

Two novel C29-5beta-sterols, opuntisterol [(24R)-24-ethyl-5beta-cholest-9-ene-6beta,12alpha-diol] (1) and opuntisteroside [(24R)-24-ethyl-6beta-[(beta-d-glucopyranosyl)oxy]-5beta-cholest-9-ene-12alpha-ol] (2), together with nine known compounds, beta-sitosterol (3), taraxerol (4), friedelin (5), methyl linoleate (6), 7-oxositosterol (7), 6beta-hydroxystigmast-4-ene-3-one (8), daucosterol (9), methyl eucomate (10) and eucomic acid (11), were isolated from the stems of Opuntia dillenii collected in Guizhou Province, China. Their structures were elucidated mainly by spectroscopic analysis. The absolute configuration of 1 were deduced from comparative 1H NMR data of the (S)- and (R)-methoxyphenyl acetate derivatives. Compounds 6-8, 10 and 11 were isolated from O. dillenii for the first time.     

仙人掌超微粉挥发性成分研究

目的：研究仙人掌中的挥发性成分。方法：利用水蒸气蒸馏法提取经超微粉碎后的仙人掌[Opuntia dillenii（Ker-Gaw.）Haw]挥发油,用GC-MS进行测定,结合计算机检索技术对分离的化合物进行结构鉴定,应用色谱峰面积归一化法计算各成分的相对百分含量。结果：共分离鉴定出32个化学成分,占总成分的98.097%,其中相对百分含量大于2%的分别确定为异丁基邻苯二甲酸酯（Isobutyl phthalate）27.492%,棕榈酸（Palmitic acid）16.716%,丁基邻苯二甲酸酯（Butyl phthalate）11.257%,薄荷脑（Menthol）6.722%,亚油酸（Linoleic acid）5.995%,壬醛（Nonanal）4.594%,乙醛（Hexanal）3.614%,十二酸（Dodecanic acid）3.244%。结论：通过对仙人掌超微粉挥发性成分的分析鉴定及相对含量测定,为综合利用仙人掌植物资源等提供科学依据。     

仙人掌中槲皮素提取条件的正交设计优选

采用浸渍法和回流法从仙人掌中提取槲皮素。试验表明:回流法提取的效率高于浸渍提取法。通过对溶剂种类、浓度、回流提取时间和仙人掌粉末粒度4个因素的选择,并以L9(34)正交设计安排实验,得出最佳回流提取工艺为:过60目筛的干燥仙人掌粉末加浓度为95%甲醇回流3 h。     

Effects of garcinol on free radical generation and NO production in embryonic rat cortical neurons and astrocytes

Garcinol (camboginol) is a polyisoprenylated benzophenone derivative isolated from fruit rind of Garcinia indica. This study was to elucidate the anti-oxidative and neuroprotective properties of garcinol in rat cortical neuron cultures. First, garcinol protects DNA from Fenton reaction-induced breakage in a dose-dependent manner, with an IC(50) value of 0.32 microM. Garcinol also inhibits xanthine oxidase activity with an IC(50) value of 52 microM and exhibits competitive inhibition. To further ascertain the neuroprotective effects of garcinol in inflammatory-mediated neurotoxicity, we utilized primary neuron/astrocyte co-cultures treated with LPS or cytokine. Our data implicate that treatment with garcinol (5 microM) for 7 days promotes neuronal attachment and neurite extension. The formation of nitric oxide (NO) by LPS in rat astrocytes has been suggested to correlate with the neurodegenerative process. In identifying the effect of neuroprotection, we found that garcinol prevented NO accumulation in LPS-treated astrocytes. Garcinol significantly reduced the expression of LPS-induced inflammatory mediators, such as iNOS and COX-2. Consequently, our results suggest that the neuroprotective effects of garcinol are associated with anti-oxidation and inhibition of iNOS induction in astrocytic cells. Garcinol may exert a similar anti-inflammatory effect and may be neuroprotective against brain injury.     

NO inhibitors function as potential anti-neuroinflammatory agents for AD from the flowers of Inula japonica

The extensive pathology studies revealed that Alzheimer’s disease (AD) is closely related to neuroinflammation and anti-neuroinflammatory agents may be potentially useful for the treatment of AD. Inula japonica is a member of the Asteraceae plant family and its flowers have been used as a healthy tea and a traditional Chinese medicine. Our continuous search for new nitric oxide (NO) inhibitory substances as anti-neuroinflammatory agents for AD resulted in the isolation of two new sesquiterpenes and ten known terpenes from the flowers of I. japonica. Their structures were established on the basis of extensive analysis of NMR and MS spectroscopic data, as well as calculated and experimental electronic circular dichroism (ECD) spectra. Among these isolates, compound 1 is a new sesquiterpene with a rare tricyclic fused skeleton, and 2 processes a 1,10-seco-eudesmane skeleton. The anti-neuroinflammatory effects were examined by inhibiting NO release in LPS-induced murine microglial BV-2 cells. The possible mechanism of NO inhibition was also investigated using molecular docking, which revealed the interactions of bioactive compounds with the iNOS protein. The present study disclosed that the flowers of I. japonica as a healthy tea are potentially useful for AD and related neuroinflammatory diseases.     

Synthesis of azaisoflavones and their inhibitory activities of NO production in activated microglia

A series of azaisoflavones were synthesized and their biological activities were evaluated for nitric oxide (NO) production and inducible NO synthase (iNOS) expression in BV-2 microglia cell lines. Among these compounds, compound 8d was the most potent with IC₅₀ 7.83 μM for inhibition of NO production. Also, compound 8d inhibited expression of iNOS in LPS-induced BV2 cells. This result suggests that compound 8d inhibited the production of NO by suppressing the expression of iNOS.     

Effects of applied NaCl on Opuntia humifusa

Plant morphology in the field in Virginia, USA, and growth responses to applied NaCl in a glasshouse were determined for two populations of Opuntia humifusa (Rafinesque) Rafinesque, one from an inland site and the other from the marine strand, which differed in potential exposure to salinity. Cladode dimensions, plant height and rooting depth varied significantly between the populations. Application of NaCl in 50 m M increments up to 400 m M every 3 days for 6 weeks caused the cladodes to decrease up to 30% in thickness, the decrease being about 20% more at 50 to 150 m M NaCl for plants from the inland site than from the marine strand. Inhibition by 150 m M NaCl of the maximum rate of net CO₂ uptake and of the total CO₂ uptake over a 24-h period was greater for the inland population. Growth, especially of roots, was inhibited by applied NaCl, with a decrease in biomass above 200 m M NaCl for plants from the inland site and not until 400 m M for those from the marine strand. Although the root Na⁺ level was the same for plants from the two populations, reaching a maximum of about 8 mg (g dry weight)⁻¹ at 200 m M NaCl, the cladode Na⁺ level was two-fold higher for plants from the marine strand than from the inland site. Thus, exclusion of Na⁺ from the cladodes is not the reason for the greater NaCl tolerance of O. humifusa from the marine strand, which is a habitat that can experience periodic episodes of high salinity.     

Bioactive terpenoids from Silybum marianum and their suppression on NO release in LPS-induced BV-2 cells and interaction with iNOS

Three new (1–3) and one known (4) bioactive terpenoids were isolated from the seeds of Silybum marianum based on the investigation to get new NO inhibitors. Their structures were determined by extensive NMR (1D and 2D NMR) and MS spectroscopic data, and the absolute configurations were identified by experimental and calculated ECD spectra. The NO inhibitory activities in murine microglial BV-2 cells and interactions with iNOS protein by molecular docking were evaluated for all compounds. The results showed that these compounds had potent NO inhibitory effects.     

Natural NO inhibitors from the leaves of Callicarpa kwangtungensis: Structures,activities, and interactions with iNOS

A phytochemical investigation to obtain new NO inhibitors resulted in the isolation of a new diterpenoid with a rare 9,10-seco-abietane skeleton (1) and twelve known terpenoids (2–13) from Callicarpa kwangtungensis. Their structures were elucidated on the basis of extensive 1D and 2D NMR spectroscopic data analyses, and the absolute configuration of compound 1 was established by comparison of the calculated and experimental electronic circular dichroism (ECD) spectra. The inhibitory activities on lipopolysaccharide-induced NO production in murine microglial BV-2 cells of these terpenoids were evaluated, and all of the compounds showed inhibitory effects. The following molecular docking studies showed interactions of the bioactive compounds with the iNOS protein.