发育毒性体外筛选模型的研究现状和进展

利用发育毒性体外评价模型开展相关安全性评价,可避免人体或动物实验耗时、费力等缺点,适用于大规模体外高通量筛选。目前常用的体外评价模型中,胚胎干细胞实验、大鼠全胚胎培养以及体外胚胎肢芽培养实验因与体内实验结果一致性较强,已得到广泛的认可和推荐。但与一般毒理学体外试验发展相比,由于发育毒性受试物在体内消化代谢路线路径的差异,使得发育毒性试验的筛选实验的发展和完善受到阻碍,因此合理的利用新技术、新方法,提高筛选体系的合理性、系统性成为未来体外评价模型的方向。     

以ITSFn诱导法为基础的神经发育毒性评价模型的建立及其有效性研究

目的 建立体外以胰岛素-转铁蛋白-硒-纤维连接蛋白(ITSFn)培养法为基础的胚胎干细胞神经发育毒性评价模型,并对其有效性进行验证,完善神经发育毒性评价体系.方法 胚胎干细胞悬滴、悬浮培养后,加入胰岛素、转铁蛋白、硒、纤维连接蛋白诱导神经细胞分化,结合细胞毒性MTT法建立神经发育毒性体外评价模型,并检测不同浓度青霉素G、苯妥英钠和氟尿嘧啶作用条件下其对胚胎干细胞神经分化能力的影响,判断受试物的神经发育毒性.结果 青霉素G、苯妥英钠和氟尿嘧啶的ID50D3 nestin分别为0.017 μg/ml、49.40 μg/ml、1 139 μg/ml,ID50D3EN-1分别0.031 μg/ml、25.63 μg/ml、1 762 μg/ ml,其发育毒性的判定均依次为无、弱和强.结论 以ITSFn诱导法为基础建立的体外神经发育毒性评价模型,能够正确判定氟尿嘧啶、苯妥英钠和青霉素G的发育毒性,可用于体外神经发育毒性的筛选和评价.     

食叶草粉对SD大鼠的致畸性研究

目的探究食叶草粉对SD大鼠的母体毒性、胚胎毒性和致畸性。方法受孕SD大鼠按体重随机分组,每组不少于16只,设溶剂对照组(蒸馏水)和食叶草粉低、中、高剂量组(分别为0.42、0.84、1.67 g/kg.BW)。在受孕第6~15d,每日以10mL/kg.BW灌胃给予受试物或等量蒸馏水。观察、记录孕鼠临床表现和体重,于孕期第20 d称重并处死母鼠,检查孕鼠妊娠情况和胎鼠发育状况,包括黄体数、死胎数、吸收胎数、活胎数,胎仔性别、体重、体长、尾长,观察有无骨骼畸形和内脏畸形。结果将各剂量组的各项指标与溶剂对照组指标进行比较,差异无统计学意义(P>0.05)。结论食叶草粉在本实验条件下对SD大鼠无母体毒性、胚胎毒性和致畸性。     

小儿牛黄清心散遗传毒性研究

目的评价小儿牛黄清心散的遗传毒性。方法采用鼠伤寒沙门菌回复突变试验(Ames试验)、小鼠骨髓细胞微核试验和细胞染色体畸变试验对小儿牛黄清心散的遗传毒性进行研究。结果小儿牛黄清心散Ames试验中受试物8～5000μg/皿剂量范围内回复突变菌落数均未超过自发回复突变组菌落数的2倍,实验结果为阴性;细胞染色体畸变试验中受试物在250～1000μg/ml剂量范围内与空白对照组比较,染色体畸变率无明显差异(P0.05),小鼠骨髓细胞微核试验中受试物在500～2000 mg/kg剂量范围内与空白对照组比较,微核率无明显差异(P0.05),实验结果为阴性。结论在本试验条件下,小儿牛黄清心散未显示遗传毒性。     

电子烟基因毒性评价方法概述

为了解电子烟的基因毒性及其评价方法,按照受试对象分类进行了综述。其中以细菌为受试对象的试验方法有细菌回复突变试验和DNA损伤分析等;以离体细胞为受试对象的试验方法有微核试验、DNA双链断裂试验、RNA转录测序试验、定向基因检测分析和Bhas细胞转化试验等;以模式动物为受试对象的试验方法有长期吸入毒性试验和生殖发育毒性试验等;以人体为受试对象的主要是临床试验和流行病学调查研究等。由于受试对象和试验方法的差异性,导致电子烟基因毒性结果的可信度和可比性较差,因此建议在评价电子烟基因毒性的过程中,应至少考虑细菌、离体细胞、模式动物和临床试验等4个层次的受试对象,通过回复突变试验、微核试验、长期吸入毒性试验和临床试验等多种试验方法获得多个基因毒性的试验终点,科学、客观和全面地综合评价电子烟的基因毒性。     

镰刀菌毒素生殖发育毒性研究进展

镰刀菌毒素是指镰刀菌属的毒性代谢产物,其中单端孢霉烯族毒素是粮食中最常见的一类污染性镰刀菌毒素,可以引起人或动物急性、慢性毒性作用,部分霉菌毒素已证明具有致突变性及致癌性。流行病学及体内、体外实验研究结果表明,部分镰刀菌毒素对人或动物生殖细胞、受孕、妊娠、分娩、哺乳等亲代生殖机能以及对其子代胚胎-胎儿发育、出生后发育产生不良影响。本文对镰刀菌毒素生殖、发育毒性研究及其进展进行综述。     

沙棘果皮渣黄酮毒理学初步评价

以沙棘果皮渣黄酮为受试物,经口染毒针对ICR小鼠做急性毒性实验、小鼠骨髓细胞染色体畸变实验、小鼠骨髓细胞微核实验、小鼠精子畸变实验,对受试物进行急性毒性实验及初步遗传毒性评价。实验结果表明:小鼠经口染毒最大耐受量(MTD)为24g/kg(>15g/kg),受试物的急性毒性分级为无毒级;在MTD以下分设高(8g/kg)、中(4g/kg)、低(2g/kg)三个剂量组考察受试物的遗传毒性,实验结果为小鼠骨髓染色体畸变率、小鼠骨髓细胞微核率以及小鼠精子畸变率均未发现增高,表明受试物不能导致小鼠骨髓细胞染色体畸变,不会诱发小鼠嗜多染红细胞微核产生,对小鼠精子无致畸作用。     

罂粟籽油毒理学研究与安全性评价

依据GB 15193—1994《食品安全性毒理学评价程序和方法》对罂粟籽油进行急性毒性试验、3项遗传毒性试验和30 d饲养试验,评价了罂粟籽油的食品安全性毒理。结果表明,罂粟籽油对2种性别的SPF级昆明种小鼠经口急性毒性试验,累计3次灌胃总量为52.8 g/kg bw,连续观察2周,动物未发现明显中毒症状和死亡,按急性毒性分级标准判定,该受试物属无毒级。3项遗传毒性试验(Ames、骨髓细胞微核试验、小鼠精子畸变试验)结果均为阴性。30 d喂养试验结果表明该受试物3.5、7.0和14.0 g/kg bw剂量对wistar大鼠连续灌胃30 d,未见明显的中毒症状和死亡。受试物各剂量组大鼠体重、食物利用率、血液学、生化学、脏器质量和脏/体比值以及病理组织多样指标无明显影响,统计学分析检验P0.05。未发现该受试物有明显的毒性作用。罂粟籽油既无毒也无任何副作用,可进一步开展其保健功能研究。     

罗布麻茶饮用安全性研究

目的:对罗布麻茶的饮用安全性进行食品安全性毒理学评价和研究。方法:罗布麻茶急性毒性实验、遗传毒性实验、传统致畸实验及短期喂养实验方法及结果判定均按照国家食品安全性毒理学评价程序和实验方法标准实施结果:罗布麻茶对雌雄大、小白鼠的急性经口LD50均大于10.0g/kg;微核试验、精子畸形试验和致畸试验结果表明罗布麻茶无致突变、致畸作用;30d短期喂养试验结果表明受试物对实验动物大鼠的生长情况、血液学和生化指标、主要脏体比及组织器官均无潜在毒性影响。结论:罗布麻茶在人体摄入量100倍范围内对实验动物的各项毒理学指标均未产生毒理作用,可作为安全的天然植物茶适合适宜人群饮用。     

荠蓝油食品安全性毒理学试验研究

对荠蓝油进行急性毒性、三项遗传毒性试验和30天喂养试验,研究荠蓝油的食品安全性毒理。荠蓝油对两种性别的SPF级昆明种小鼠急性经口毒性试验,累计三次灌胃总量为56.4g/kg.bw,连续观察两周,动物未发现明显中毒症状和死亡,按急性毒性分级标准判定,该受试物属无毒级。三项遗传毒性试验(A-mes、骨髓细胞微核试验、小鼠精子畸变试验)结果均为阴性。30天喂养试验结果表明:该受试物3.5,7.0,14.1g/kg.bw剂量对wistar大鼠连续灌胃给予30天,动物未见明显的中毒症状和死亡。受试物各剂量组大鼠体重、食物利用率、血液学、生化学、脏器重量和脏/体比值以及病理组织学等指标与食用植物油对照组比较,差异无显著性。荠蓝油既无毒也无任何副作用。     

Antioxidant activity of phenolic compounds: from in vitro results to in vivo evidence

Over last decade an increasing interest for antioxidants in foods has arisen. The healthy properties of antioxidants related to the prevention of degenerative diseases are the main cause of this boom. An antioxidant prevents the oxidation process, the initial step of development of degenerative diseases, cancer and many others. Literature encompasses analytical methodology development to assess antioxidant properties of foods and beverages. The screening of antioxidant activity of foodstuffs is the subject of a large number of articles. Special interest has been addressed to wine, tea and chocolate. However, the crucial key in the prevention of disease is the action these antioxidants exert after their consumption. Studies involving human subjects are scarce due to the requirements of availability of volunteers and conditions to test are limited. This review summarizes data related to in vitro antioxidant activity of foods, emphasizing the main role of phenolic compounds. A critical comparison is realized between the biological significance of these values and the biological significance of in vivo measurements. In addition, the Plasma Antioxidant Capacity is evaluated and selected as biomarker for in vivo antioxidant status of human organism. In a second part, data collected from different intervention studies performed up to date are compiled and discussed. This review summarized data related to in vitro antioxidant activity of foods, emphasizing the main role of phenolic compounds. A critical comparison is realized between the biological significance of these values and the biological significance of in vivo measurements. In addition, the Plasma Antioxidant Capacity is evaluated and selected as biomarker for in vivo antioxidant status of human organism. In a second part, data collected from different intervention studies performed up to date are compiled and discussed. The original contribution of this work is to compile data of Plasma Antioxidant Capacity after dietetic intervention studies taking into account the portion of food ingested. In addition, we calculated the antioxidant compounds content (phenolic content, ascorbic acid, vitamin E and carotenoids) contained in each food ingested to evaluate better their impact in Plasma Antioxidant Capacity. Intervention studies are grouped by the length of intervention and type of food ingested. Results reported in literature reveal that the increment in Plasma Antioxidant Capacity largely depends on analytical method used.     

When nano meets stem: the impact of nanotechnology in stem cell biology

Nanotechnology and biomedical treatments using stem cells are among the latest conduits of biotechnological research. Even more recently, scientists have begun finding ways to mate these two specialties of science. The advent of nanotechnology has paved the way for an explicit understanding of stem cell therapy in vivo and by recapitulation of such in vivo environments in the culture, this technology seems to accommodate a great potential in providing new vistas to stem cell research. Nanotechnology carries in its wake, the development of highly stable, efficient and specific gene delivery systems for both in vitro and in vivo genetic engineering of stem cells, use of nanoscale systems (such as microarrays) for investigation of gene expression in stem cells, creation of dynamic three-dimensional nano-environments for in vitro and in vivo maintenance and differentiation of stem cells and development of extremely sensitive in vivo detection systems to gain insights into the mechanisms of stem cell differentiation and apoptosis in different disease models. The present review presents an overview of the current applications and future prospects for the use of nanotechnology in stem cell biology.     

蜂胶复合胶囊毒理学的动物实验观察

目的:蜂胶复合胶囊为蜂胶与中药组成的复方制剂,为了判断其对人体健康是否产生危害,特进行了安全性毒理学评价。方法:急性毒性半数致死量(LD50)实验,小鼠骨髓细胞微核实验,精子畸变实验,Ames 实验,30d 喂养实验。结果:该胶囊经急性毒性半数致死量(LD50)实验,数据显示,该胶囊无毒,三项致突实验均为阴性结果,在传统致畸实验中未见大鼠发育毒性和胚胎毒性,在30d 喂养实验中也无异常发现。结论:蜂胶复合胶囊临床使用安全可靠。     

Biological activities of oligoketide pigments of Monascus purpureus

Rubropunctatin (1) , monascorubrin (2) , monascin (3) and ankaflavin (4) were purified from the mycelium of Monascus purpureus by flash chromatography on silica gel or reversed phase. Their embryotoxicity towards chicken embryos decreased in the order 2> 1> 3> 4 . The lower homologues 1 and 3 exhibited teratogenic effects on these organisms. Significant antibiotic activities against Bacillus subtilis and Candida pseudotropicalis were found with compounds 1 and 2 . Immunosuppressive activity on mouse T-splenocytes was most pronounced with compounds 3 and 4 . None of the compounds showed significant cytotoxic activity towards rat hepatocytes in vitro . Incubation of resting cells of M. purpureus with glycine afforded the dark-red compounds 5 and 6 where the pyran moiety of 1 and 2 changed into the N-substituted dihydropyridine moiety by replacement of the O-atom by the amino group of glycine. Compounds 5 and 6 were less biologically active than the major pigments 1 - 4 .     

Sunscreen in vitro spectroscopy: application to UVA protection assessment and correlation with in vivo persistent pigment darkening

In the present study, we have described an in vitro spectroscopic method to evaluate the sunscreen products for UVA sun protection factor. The roughened PMMA plates have been used as a transparent substrate on to which the test product is spread. The UVA protection factors have been deduced from the UV-transmittance data measured in the UVA area. In order to be as close as possible to the in vivo protection factors, issued from the PPD end-point, the treated polymethylmethacrylate (PMMA) plates are submitted to different UV-irradiation doses, before the measurement. The correlation in vitro/in vivo is poor when the sunscreens are not irradiated. A UV dose of about 2 minimal pigmenting dose (MPD) is enough to achieve a good correlation between in vitro and in vivo data issued from the 13 tested sunscreens. These results are consistent with the fact that the photostability of sunscreens is challenged during an in vivo PPD test.     

Esterase variation in Tribolium confusum (Coleoptera: Tenebrionidae): genetic analysis of interstrain crosses in relation to malathion resistance

General esterase activity variation among individuals and strains of Tribolium confusum (du Val) is mostly due to a single electrophoretic locus. A strain (CFxlH) selected for very strongly staining isozyme (EST2), was reciprocally crossed with the black mutant laboratory strain (CFbb) which has very weak EST2. EST2 is not linked to the black locus and is inherited as a monogenic, autosomal trait. Similar results were obtained when CFxlH was reciprocally crossed with the sister strain (CFxlL) selected for low activity. Slight deviations from Mendelian expectation in the latter crosses suggest that maternally inherited effects modify EST2 activity in these strains.CFbb and CFxlL both have low EST2 activity, and when intercrossed, all offspring had the EST2L pattern, suggesting that the EST2 loci in the two strains are the same or very tightly linked.Malathion resistance in one strain (MN61) seems to be inherited in a monofactorial fashion, with dominance of the resistant allele. MN61 is fixed for the high-activity EST2 phenotype. Addition of triphenyl phosphate (TPP) synergised the effects of the pesticide, indicating that malathion resistance is due to carboxylesterase activity. CFxlH and CFxlL had similar malathion resistance despite the dramatic difference in EST2 activity: resistance is not due to EST2, the major contributor to the hydrolysis of α-naphthyl acetate (and probably other naphthyl esters).     

Identification of C-glycoside flavonoids as potential mutagenic compounds in kava

ABSTRACT:  Kava ( Piper methysticum ) extract products have been implicated in a number of severe hepatotoxicity cases. However, systematic toxicological studies regarding kava consumption have not been reported. In this study, 6 major kavalactones and different solvent fractions of kava roots, leaves, and stem peelings were evaluated for their mutagenic potential. None of the kavalactones was found to be positive in the experimental concentration ranges tested by the umu test (a sensitive test for point mutations). However, among the different solvent fractions, the n -butanol fraction of kava leaves was positive. Further investigations using bioassay-directed isolation and analysis indicated that 2 C -glycoside flavonoid compounds accounted for the positive mutagenic results. Two isolated compounds were identified as 2"- O -rhamnosylvitexin and schaftoside by NMR and MS techniques.     

大豆EST—SSR标记开发及与Genomic—SSR的比较研究

对458220条大豆EST序列进行SSR搜索,共检测出EST—SSR序列39989条,经拼接得到无冗余EST—SSR序列8190条,包括357种重复基元。其中二、三核苷酸重复基元类型居多,分别占无冗余EST总数的11．13％和16％,统计得到二核苷酸重复类型12种,三核苷酸重复类型60种。以含有简单重复序列的元冗余EST序列设计200对引物,其中148对引物有清晰且单一条带扩增产物,以30份大豆品种资源进行引物筛选,获得多态性引物31对。以21份大豆不同基因型的基因组DNA为模板选取30对显示多态性的大豆EST—SSR引物和30对大豆基因组SSR引物进行扩增,带型统计结果显示：大豆EST—SSR与基因组SSR在供试基因型间多态性指数均值分别为0．55和0．44,二者揭示的多态性水平差异不大。从而说明利用生物信息学方法基于大豆EST开发SSR标记是切实可行的,大豆EST—SSR可以用于大豆遗传多样性分析,是大豆DNA分子标记体系的一个重要补充。     

THE POLYMORPHISM OF ESTERASES IN YEAST (SACCHAROMYCES CEREVISIAE)

In laboratory strains of yeast (Saccharomyces cerevisiae) two esterase loci, EST1 and EST2, are known. Two more, EST3 and EST4, were found in samples of wine yeast from 40 localities in Europe.