马兜铃酸致突变及致癌性研究进展*

“中草药肾病”事件之后，马兜铃酸肾毒性受到了全球学者的关注，而随着马兜铃酸肾病患者伴发泌尿系统肿瘤报道的日渐增多，阐明其致突变和致癌机制也成为其毒性研究的另一焦点，马兜铃酸Ⅰ和Ⅱ是马兜铃酸的2种主要成分，为明确的遗传毒性致突变物，现重点围绕其在体内的代谢活化过程、DNA加合物形成、分布特点及导致癌基因突变等阐述马兜铃酸致突变致癌分子机制的研究现状。     

马兜铃酸细胞分子毒理学研究进展

马兜铃酸属于硝基菲类化合物,广泛存在于马兜铃属中药中,具有肾毒性和潜在的致癌作用。马兜铃酸诱导肾小管上皮细胞纤维化及凋亡;促进细胞周期加速,而导致泌尿道上皮异常增殖;经还原代谢,并与DNA形成加合物,使ras基因和p53基因突变,进而诱发癌变。本文对马兜铃酸的细胞分子毒性机制进行了综述,并对可能的减毒方法进行了探讨。     

含马兜铃酸的药物临床应用分析

本文对基层使用含马兜铃酸的中药的使用情况做一总结研究,以了解基层医院的医生对此类药物的临床使用及对马兜铃肾病的认识情况,从而提出如何加强新理论、新知识在基层医生中的推广和学习.     

马兜铃酸肾病的临床病理分析

目的 探讨马兜铃酸肾病的临床病理特点。方法 回顾性分析3例马兜铃酸肾病患者的临床表现及病理资料。结果 2例急性马兜铃酸肾病临床表现为：消化道症状、肾功能减退、尿酶升高、电解质紊乱;病理诊断为急性肾小管坏死。1例慢性马兜铃酸肾病临床表现为：贫血、尿检异常、高血压、肾功能减退,病理诊断为慢性间质性肾炎。结论 含有马兜铃酸的中药有肾损害,可致马兜铃酸肾病,其临床表现病理变化有一定特点。     

中药马兜铃酸的研究进展

本文总结了马兜铃酸的化学结构、含马兜铃酸的中草药及中成药、马兜铃酸的药理作用和毒性作用、马兜铃酸肾病。通过本文的综述,使医药人员对马兜铃酸有一个全面、正确的认识,以指导临床安全、合理、规范使用含有马兜铃酸的中药。     

马兜铃酸肾病研究的新进展

根据近年有关研究和报道对含马兜铃酸中药的毒性成分、马兜铃酸的代谢、马兜铃酸肾病的发病机制、临床特征及其诊断方法进行综述,旨在对马兜铃酸的毒理学及马兜铃酸肾病的诊治加深认识。     

含马兜铃酸的中药临床应用状况分析

目的通过临床对含马兜铃酸的中药使用情况进行分析,研究含马兜铃酸的中药使用临床应用情况以及对马兜铃酸肾病的认识情况。方法通过临床对中药细辛、威灵仙、川木桶、汉防己等药物的使用量比较含马兜铃酸药物的临床使用情况。并且对医院的医师进行含马兜铃酸药物组成的认识与使用情况进行问卷调查,同时也对马兜铃酸肾病的情况知晓程度进行研究,分析含马兜铃酸的中药临床应用状况。结果通过医院临床使用药物的调查以及对医师使用含马兜铃酸的中药进行问卷调查发现,含马兜铃酸的药物使用量一直呈上升的趋势,但是马兜铃酸肾病并没有受到医师的重视。结论随着含马兜铃酸的中药的大量使用,临床也要对药物所产生的毒副作用进行重视,要加强对马兜铃酸肾病的研究,培养医师对药物毒副作用的认识。     

马兜铃酸的毒理学现状

目的:介绍马兜铃酸的毒理学研究进展方法:方法:参考国内外相关文献,进行综合、分析、归纳。结果:马兜铃酸具有肾毒性、消化道毒性、致癌性、致突变性和基因毒性。结论:要辨证合理使用含有马兜铃酸成分的中药材。     

超高效液相-质谱法测定滴通鼻炎水中马兜铃酸Ⅰ、Ⅱ的含量

目的 测定滴通鼻炎水中马兜铃酸Ⅰ、马兜铃酸Ⅱ的含量,为其质量控制提供借鉴。方法 采用超高效液相-质谱法(UPLC-MS/MS)同时测定滴通鼻炎水中马兜铃酸Ⅰ、马兜铃酸Ⅱ的含量。色谱柱采用Waters-ACQUI UPLC HSS T3 C₁₈(2.1 mm×100 mm,1.8μm),采用乙腈为流动相A,0.1%甲酸含1 mmol·L^-1乙酸铵溶液为流动相B,梯度洗脱,电喷雾离子源(ESI),正离子多反应监测模式,以标准曲线法计算含量。结果 17批滴通鼻炎水中有9批样品未检出马兜铃酸Ⅰ(检出限0.13 pg),8批样品中检出马兜铃酸Ⅰ,含量在0.41～3.60 ng·mL^-1。所有样品中均未检出马兜铃酸Ⅱ(检出限0.41 pg)。结论 建立了UPLC-MS/MS同时测定滴通鼻炎水中马兜铃酸Ⅰ、马兜铃酸Ⅱ含量的方法,该方法专属性强、灵敏度高、重复性好,可为滴通鼻炎水中马兜铃酸Ⅰ、马兜铃酸Ⅱ的质量控制提供参考。     

马兜铃酸毒性作用的研究进展

从动物实验、体外实验、临床研究等方面综述国内外马兜铃酸肾毒性作用的研究进展,尤其是目前研究最多的以急、慢性肾小管间质病变为主的肾损害.提出马兜铃酸的毒性应以预防为主,严格掌握用药剂量和时间,同时加强临床血药浓度的监测,从各方面减少其毒性作用的发生.     

阿苯哒唑硫氧化代谢产物的合成及电喷雾质谱分析

目的合成阿苯哒唑硫氧化物 ,研究阿苯哒唑及其硫氧化物的质谱断裂途径。方法在室温条件下 ,使用过氧化氢将阿苯哒唑氧化成相应的亚砜和砜 ,用硅胶柱层析方法进行分离纯化。采用电喷雾质谱法检测阿苯哒唑及合成产物。结果一次反应同时制得 2种产物 ,[5 (丙基亚砜基 ) 1H 苯并咪唑 2 基 ]氨基甲酸甲酯 (Ⅱ )和 [5 (丙砜基 ) 1H 苯并咪唑 2 基 ]氨基甲酸甲酯 (Ⅲ )经质谱检测其准分子离子峰分别为m/z 2 82和m/z 2 98。结论阿苯哒唑及其 2种氧化产物质谱断裂方式存在共性 ,易生成 [M +H - 32 ]+ 或 [M +H - 4 2 ]+ 的特征碎片离子 ,构成二级或三级质谱的基峰     

马兜铃酸类成分检测与分析研究进展

马兜铃酸类成分是广泛存在于马兜铃科植物中的硝基菲类化合物,已被证实具有肾毒性、致癌和致基因突变等作用。我国自2003年以来采取一系列风险控制措施,其中马兜铃酸含量高的关木通、广防己和青木香等药材已被禁用。目前,一些马兜铃酸含量低的中药材与中成药仍在使用中,鉴于马兜铃酸成分对人体的严重危害性,有必要进一步加强相关药材与制剂的风险评估。在归纳马兜铃酸类成分结构等基本信息的基础上,对近年来的检测分析方法进展进行了总结,为其风险控制与安全使用提供了科学依据。     

Detection and simultaneous quantification of three smoking-related ethylthymidine adducts in human salivary DNA by liquid chromatography tandem mass spectrometry

Smoking cigarette increases levels of certain ethylated DNA adducts in certain tissues and urine. Cigarette smoking is a major risk factor of various cancers and DNA ethylation is involved in smoking-related carcinogenesis. Among the ethylated DNA adducts, O²-ethylthymidine (O²-edT) and the promutagenic O⁴-ethylthymidine (O⁴-edT) are poorly repaired and they can accumulate in vivo. Using an accurate, highly sensitive, and quantitative assay based on stable isotope dilution nanoflow liquid chromatography–nanospray ionization tandem mass spectrometry (nanoLC–NSI/MS/MS), O²-edT, N³-edT (N³-ethylthymidine), and O⁴-edT adducts in human salivary DNA were simultaneous detected and quantified. Saliva is easily accessible and available and it can be a potential target in searching for noninvasive biomarkers. Under the highly selected reaction monitoring (H-SRM) mode, salivary samples from 20 smokers and 13 nonsmokers were analyzed. Starting with 50 μg of DNA isolated from about 3.5 mL of saliva, levels of O²-edT, N³-edT, and O⁴-edT in 20 smokers’ salivary DNA samples were 5.3 ± 6.2, 4.5 ± 5.7, 4.2 ± 8.0 in 10⁸ normal nucleotides, respectively, while those in 13 nonsmokers were non-detectable. In addition, statistically significant correlations (p < 0.0001) were observed between levels of O²-edT and N³-edT (γ = 0.7388), between levels of O²-edT and O⁴-edT (γ = 0.8839), and between levels of N³-edT, and O⁴-edT (γ = 0.7835). To the best of our knowledge, this is the first report of detection and quantification of these three ethylthymidine adducts in human salivary DNA, which might be potential biomarkers for exposure to ethylating agents and possibly for cancer risk assessment.     

Formation of MTBE-DNA adducts in mice measured with accelerator mass spectrometry

Methyl tert-butyl ether (MTBE) is a gasoline oxygenate and antiknock additive substituting for lead alkyls currently in use worldwide. Previous studies have shown that MTBE at very high doses induces tumors in rodents. The aim of the present study was to examine directly the binding ability of MTBE onto DNA, demonstrating its potential genotoxicity. MTBE-DNA adducts and their decay kinetics in mice have been measured by using doubly 14C-labeled MTBE with an advanced, ultrasensitive technique: accelerator mass spectrometry (AMS). It was found that MTBE definitely formed adducts with DNA in mouse lung, liver, and kidney in a log/log linear dose-response relationship. The distribution sequence of DNA adducts in these tissues is: lung > liver > kidney. The level of MTBE-DNA adducts peaked at 12 h postadministration in the lung and peaked at 6 h postadministration in the liver. Then the adducts declined rapidly until 5 days postadministration and thereafter declined much more slowly. To our knowledge, this is the first report on DNA adduction with MTBE in vivo. The mechanism of the formation of MTBE-DNA adducts also is discussed.     

Synthesis and mass spectra of labelled 4(5)‐nitro‐1H‐imidazole‐5(4)‐carbonitriles

Cine nucleophilic substitution of 1,4‐dinitroimidazole and its 2‐methyl derivative with nitrogen‐15 or carbon‐13 potassium cyanides afforded, respectively, labelled 4(5)‐nitro‐1H‐imidazole‐5(4)‐carbonitriles. Detailed mass spectra analysis led to the conclusion that during fragmentation in mass spectrometer the labelled atoms are present in all the main fragmentation ions of m/z higher than 42. Copyright © 2002 John Wiley & Sons, Ltd.     

马兜铃酸毒理学性研究与启示

有关马兜铃酸的毒理实验国内外均有报道,尤其国外在毒理学方面做了大量研究.大量的实验提示:马兜铃酸的肾毒性与剂量呈相关性;遗传毒性研究提示马兜铃酸具有致突变作用;在对大鼠和小鼠的长期毒性研究中发现:动物可发生局部和全身肿瘤,且肿瘤的发生与给药时间和剂量呈相关性;并发现动物的主要毒性与人的不良反应有相关性.马兜铃酸的相关实验研究提醒有关方面应重视马兜铃酸问题,使传统中药更好地发挥防病治病作用.     

Synthesis of 5,5,6,6‐D4‐L‐lysine‐aflatoxin Bl for use as a mass spectrometric internal standard

Human exposure to the hepatocarcinogenic mycotoxin aflatoxin B_l results in modification of serum albumin lysine ε‐amino residues to form lysine‐aflatoxin adducts. A perdeuterated reference standard is now required to quantitatively measure this adduct in epidemiologic studies of liver cancer using isotopic dilution mass spectrometry. A convenient method for the preparation of D4‐L ‐lysine‐AFB_l using commercially available 5,5,6,6‐D4‐l ‐lysine is demonstrated for the first time. The application of two standard α‐amino protection methods is also reported that simplifies the production of natural isotopic abundance lysine‐AFB_l over the currently used method employing N_α‐acetyl‐l ‐lysine. t‐Boc‐N_α‐lysine was used to prepare lysine‐AFB_l; however, a preferred method for directing reaction of AFB_l‐dialdehyde to the ε‐amino group of 5,5,6,6‐D4‐l ‐lysine utilized cupric ions that were spontaneously removed during the reverse phase HPLC purification of D4‐lysine‐AFB_l using 1% HOAc. This strategy eliminates the need to otherwise synthesize and purify t‐Boc‐N_α‐ or N_α‐acetyl‐5,5,6,6‐D4‐lysine and then TFA or enzymatically deprotect overnight to obtain the target compound. Copyright © 2004 John Wiley & Sons, Ltd.     

Systematic analysis of glycerol: colourimetric screening and gas chromatography–mass spectrometric confirmation

Glycerol is a naturally occurring polyol in the human body, essential for several metabolic processes. It is widely used in the food, pharmaceutical, and medical industries and in clinical practice as a plasma volume expander (PVE). Athletes, however, may use glycerol to mask the presence of forbidden substances or to enhance performance, inclusively through hyperhydration achieved by glycerol ingestion with added fluid. These practices are considered doping, and are prohibited by the World Anti‐Doping Agency (WADA). Therefore, glycerol was introduced in the prohibited list. Doping through glycerol ingestion can readily be identified by detection of elevated glycerol concentrations in urine. In this paper, a protocol for the fast detection of glycerol in urine is proposed. It consists of a previous visual colourimetric screening, followed by a quantitative/qualitative confirmation analysis by mass spectrometry. The screening procedure involves a reaction in which polyhydric alcohols are oxidized by periodate to formic acid and formaldehyde, which is detected by the addition of a fuchsin solution. For the subsequent qualitative/quantitative confirmation analysis, a gas chromatography–mass spectrometry based approach with a non‐deuterated internal standard and a drying step of only 10 min is proposed. The linear correlation was demonstrated within WADA´s threshold range. The calculated RSD were 2.1% for within‐day precision and 2.8% for between‐day precision. The uncertainty estimation was calculated, and a value of 2.7% was obtained. The procedure may also be used for the analysis of other polyols in urine, as for example the PVE mannitol. Copyright © 2015 John Wiley & Sons, Ltd.