Polyethylene sebacate: Genotoxicity,mutagenicity evaluation and application in periodontal drug delivery system

The objective of the present study is to evaluate Polyethylene sebacate (PES) for its toxicity profile including oral toxicity, genotoxicity and mutagenicity. PES was synthesised, and characterised by gel permeation chromatography, FTIR, ¹H-NMR, differential scanning calorimetry and X-ray diffraction. Oral toxicity studies revealed PES to be nontoxic up to 3000 mg/kg body weight with no significant changes in serum biochemistry. The standard battery of genotoxicity tests including micronucleus test, chromosomal aberration and comet assay revealed PES as nongenotoxic. Mutagenicity of PES was evaluated using the Ames microplate format mutagenicity assay sample kit using TA98 and TA100 strains of Salmonella typhimurium, both in presence and absence of Aroclor 1254 induced rat liver S9. Ames assay confirmed PES to be nonmutagenic. Periodontal implants of PES of varying roxithromycin/PES ratios and different diameter were prepared. A decrease in in vitro drug release was seen with increase in diameter of the implants. Release rates, however, increased with increase in PES concentration, and were attributed to decreased crystallinity of roxithromycin, confirmed by the DSC thermographs and XRD spectra. Roxithromycin release from the implants followed Higuchi kinetics and exhibited controlled release. The results suggest PES as a safe polymer for biomedical and pharmaceutical applications. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:4781–4795, 2009     

Comparative mutagenicity studies of azo dyes and their reduction products in Salmonella typhimurium

The arabinose-resistant and Ames assay systems of Salmonella typhimurium were used to evaluate the mutagenic potential of azo dyes and their aromatic amine reduction products. Azo dyes, namely direct black 38, direct blue 15, and direct red 2, were mutagenic in the arabinose-resistant and Ames assays with both hamster and rat liver S9 activation. Both assays gave relatively higher mutagenic responses with hamster S9. Reduction products of these dyes, namely benzidine, o-dianisidine, and o-tolidine, were mutagenic in the Ames assay. Benzidine was weakly mutagenic and o-dianisidine and o-tolidine were nonmutagenic in the arabinose-resistant assay. These results indicate that both arabinose-resistant tester SV50 and Ames tester TA98 were sensitive in detecting mutagenicity of azo dyes. The use of the standard plate protocol with Ames tester TA98 is more efficient than the modified azo dye protocol in detecting mutagenicity of aromatic amine reduction products. Additional modifications in either the standard plate or modified azo dye protocols may improve detection of mutagenicity of these compounds in the arabinose-resistant assay system.     

Toxicity assessment of industrial effluents from S. Paulo state,Brazil, using short-term microbial assays

Microorganisms have demonstrated several attributes that make them attractive for use in quick screening of effluents and chemicals for toxicity. The aim of this study was to evaluate the acute toxicity and mutagenicity of industrial effluents from São Paulo State using short-term microbial bioassays. Samples of industrial effluents and receiving waters were analyzed for acute toxicity by the Microtox system, a motility test using Spirillum volutans, growth inhibition of Pseudomonas fluorescens, and dehydrogenase assay; for mutagenicity, these samples were analyzed by Salmonella typhimurium (Ames test), Escherichia coli WP₂, and Saccharomyces cerevisiae reversion mutation assays. Among the acute toxicity assays carried out in this study, the Microtox and S. volutans tests showed good sensitivity and general good agreement with the Daphnia similis assay, which demonstrates that these tests are potentially useful as toxicity indicators for the industrial effluents and receiving waters considered. In relation to mutagenicity assays, good results were obtained with the three methods tested. The detection of mutagens in the industrial effluents considered indicates that some constituents of these waste waters discharged in receiving waters can cause adverse biological effects and could be deleterious from a public health standpoint. The data of this research emphasize the importance of acute toxicity and mutagenicity assays as supplementary approaches for a rapid and efficient action in water pollution control, and for evaluation of potential toxic chemical effects.     

False Positive Result for a Peptide Drug in the Gene Conversion Assay with Saccharomyces cerevisiae Strain D7

False Positive Result for a Peptide Drug in the Gene ConversionAssay with Saccharomyces cerevisiae Strain D7. DEPASS, L. R.,CHAN, R. L., JAGANNATH, D. R., AND HEYMAN, I. A. (1991). Fundam.Appl Toxicol. 17, 627–634. A battery of mutagenicity testswas performed with nafarelin, an agonist analogue of luteinizinghormone releasing hormone (LHRH) containing tryptophan (Trp)and histidine (His). Included were the Ames assay and the geneconversion assay with yeast strain D7. Both tests were negativewithout S9 activation, and the Ames test was negative with S9,but the yeast test was positive with S9 activation. Since theyeast test is based on conversion of cells to Trp independence,release of Trp by metabolism of the drug could account for thepositive result The test was repeated using Trp instead of thedrug. The result was positive even at the lowest Trp concentration.In another experiment with the drug, amino acid analysis ofthe incubation mixture revealed the presence of Trp but no detectableHis. Since the Ames test is based on mutation to His-independentcells, these data are completely consistent with the negativeresult in the Ames test and the false positive result in theyeast test. These data suggest the need for caution in interpretingthe results from mutagenicity assays with peptide drugs.     

油松花粉遗传毒性研究

目的 探讨油松花粉的遗传毒性,为其应用提供安全性毒理学评价依据.方法 用鼠伤寒沙门细菌营养缺陷型突变株TA97(a)、TA 98、TA 100和TA 102,采用平皿掺入法进行Ames实验,将实验分为加和不加代谢激活系统S9 2组平行实验.受实物设5个剂量组(0.008、0.040、0.200、1.000、5.000 mg/皿).应用小鼠骨髓嗜多染红细胞微核实验,检测小鼠骨髓嗜多染红细胞微核率;利用小鼠精子畸形实验,观察不同浓度的油松花粉致小鼠精子畸形的数目.结果 在Ames实验中,油松花粉各剂量组引起的回变菌落数未超过对照组自发回变菌落数的1倍以上;小鼠骨髓嗜多染红细胞微核实验显示,油松花粉3个剂量组的微核发生率均在正常范围内,与阴性对照组比较差异无显著性(P＞0.05),与阳性对照组比较差异显著(P＜0.05);小鼠精子畸形实验显示,油松花粉3个剂量组的精子畸形率均在正常范围内,与阴性对照组比较差异无显著性(P＞0.05),与阳性对照组比较差异显著(P＜0.05).结论 油松花粉对所实菌株、小鼠体细胞及生殖细胞无诱变性.     

Toxicological evaluation of complex mixtures: fingerprinting and multivariate analysis

The present paper describes a strategy for toxicological evaluation of complex mixtures based on chemical "fingerprinting" followed by pattern recognition (multivariate data analysis). The purpose is to correlate chemical fingerprints to measured toxicological endpoints, identify all major contributors to toxicity, and predict toxicity of additional mixtures. The strategy is illustrated with organic extracts of exhaust particles which are characterized by full scan gas chromatography-mass spectrometry (GC-MS). The complex GC-MS data are resolved into peaks and spectra for individual compounds using an automated curve resolution procedure. Projections to latent structures (PLS) is used for the regression modeling to correlate the GC-MS data to the measured responses; mutagenicity in the Ames Salmonella assay. The regression model identifies those peaks that co-vary with the observed mutagenicity. These peaks may be identified chemically from their spectra. Furthermore, the regression model can be used to predict mutagenicity from GC-MS chromatograms of additional samples.     

3种促智药:石杉碱甲、茴拉西坦和吡乙酰胺的诱变作用和诱变协同作用

在鼠伤寒沙门菌/微粒体系统中测试了石杉碱甲、茴拉西坦和吡乙酸胺的诱变作用。结果表明,药物浓度从1μg-5mg/皿对TA97、TA98、TA100和TA1024个菌株,在无S_9代谢系统上所测的这3个药和有S_9代谢系统所测的石杉碱甲、茴拉西坦均未显示任何诱变作用。向拉西坦和吡乙酰胺在诱变协同实验中均不增加对-硝基喹啉在TA98上和甲基磺酸甲酯在TA100上诱发的回变数。ICR纯系小鼠骨髓微核试验,剂量高达1/2LD_(50)时不增加嗜多染红细胞的微核率,也无骨髓抑制作用.     

Safety evaluation of polyphenols extracted from hop bracts.

Hop bract polyphenols contain polyphenols as promising functional ingredients. To assess the safety of topical hop bract polyphenols, Hopsphenon, we examined acute, 14-day, 28-day and 90-day toxicity tests in rats, and mutagenicity tests using Ames test and micronucleus test in mice. The acute, 14-day, 28-day and 90-day toxicity tests revealed that Hopsphenon produced no symptoms of significant injury. The lethal dose of hop bract polyphenols is greater than 2000 mg/kg. The Ames test in the absence of S9 mix for TA98 and in the presence of S9 mix for TA1537 revealed that Hopsphenon had slight mutagenicity at a high dose of 5000 microg/plate; however, in the micronucleus test, Hopsphenon was negative. These tests demonstrated that hop bract polyphenols are safe and do not cause any detrimental effects in vivo under the conditions investigated in this study.     

猫眼草水煎液体外致突变性的研究

目的检验猫眼草水煎液的致突变性;改进经典的A-mes试验体系使之适应于中药体外致突变性检验。方法通过经典的Ames试验检测猫眼草的体外致突变性;通过哺乳动物骨髓细胞染色体畸变试验检测猫眼草的致畸作用;改进的Ames试验通过增设含补充组氨酸(含量对应于猫眼草水煎液中组氨酸浓度)的阴性对照,排除样品中组氨酸成分对试验结果的影响。结果猫眼草水煎液在经典的Ames试验中为强阳性;对哺乳动物骨髓细胞染色体致畸作用为阴性;在改进的Ames试验中猫眼草水煎液的致突变性为阴性。结论经典的Ames试验不适合猫眼草水煎液致突变性检测,改进后的Ames实验体系适合。猫眼草水煎液在体外和体内均没有致突变性。     

百草胶囊的毒性研究

目的　研究百草胶囊的毒性。方法　采用最大耐受剂量 (MTD)试验 ,小鼠骨髓嗜多染红细胞微核试验 ,小鼠精子畸形试验 ,Ames试验和大鼠 30d喂养试验 ,分别观察百草胶囊的急性毒性 ,遗传毒性和亚急性毒性。结果　百草胶囊对小鼠经口MTD大于 16 0 0 0mg/kg ;对小鼠骨髓嗜多染红细胞微核试验无诱发微核增多作用 ;小鼠精子畸形试验未见导致精子畸形和畸形率增高 ;Ames试验在加与不加S9的条件下均无致突变性 ;大鼠 30d喂养试验未观察到中毒表现 ,百草胶囊各剂量组动物体重 ,食物利用率 ,血液学和血液生化学指标值 ,各脏器的脏 /体比值与空白对照组比较差异均无显著意义 (P >0 0 5 )。主要脏器在外观形态和组织学上均无异常变化。结论　百草胶囊对动物的生长发育、造血功能、肝肾功能、器官组织均无明显毒性。     

Mutagenic activity of surface soil and quantification of 1,3-, 1,6-, and 1,8-dinitropyrene isomers in soil in Japan

To clarify the mutagenic potential of nonagricultural surface soil in Japan, 110 soil samples were collected from five geographically different areas between November 1996 and March 1997, and organic extracts of the soil samples were examined by the Ames/Salmonella assay. Most of the soil extracts showed mutagenicity toward both strains TA98 and TA100 in the presence and/or absence of a mammalian metabolic activation system (S9 mix), suggesting that surface soil is largely contaminated with environmental mutagens. Soil samples collected at Hekinan, Kobe, and Osaka were highly mutagenic toward both strains, and their potencies toward TA98 without S9 mix were extremely high, inducing more than 12 000 revertants per gram of soil. On the other hand, soil samples from Muroran showed strong mutagenicity toward TA100 with S9 mix. Furthermore, 1, 3-dinitropyrene (DNP), 1,6-DNP, and 1,8-DNP in soil samples collected at 10 sampling sites in three metropolitan areas were quantified by fluorometric detection of the corresponding diaminopyrene isomers using high-performance liquid chromatography (HPLC). Three DNP isomers were detected in all soil samples, and the amounts of 1,3-, 1,6-, and 1,8-DNP isomers in the soil samples were 12-3270, 14-5587, and 13-6809 pg/g, respectively. The gross amount of three DNP isomers in surface soil collected at Hekinan was more than 10 ng per gram of soil. The highest contribution ratios of DNP isomers to the mutagenicity of soil extracts were observed for the samples collected at Osaka, and the total of the contribution ratios of three DNP isomers was about 50%. These results suggest that surface soil is largely contaminated with mutagenic compounds and that DNP isomers are one class of major mutagenic and carcinogenic compounds contaminating surface soil.     

霍山石斛类原球茎免疫调节活性的有效部位及其毒理安全性评价

目的研究霍山石斛类原球茎对小鼠免疫调节活性的有效部位及其毒理安全性。方法制备霍山石斛类原球茎冷冻干燥物、醇提物、水提物、醇溶物、醇沉物、多糖等不同提取部位;检测不同提取部位对ConA诱导的小鼠脾淋巴细胞增殖反应及免疫器官指数的影响;采用急性毒性试验、Ames试验、大鼠30d喂养实验考察多糖的毒性及致突变作用。结果水提物、醇沉物和多糖各剂量组均可以促进ConA诱导的小鼠脾淋巴细胞增殖反应和免疫器官指数的增加,且具有浓度依赖性,其中,多糖的促进作用最强;多糖对小鼠ig给药的最大耐受量大于15.6g/kg,属基本无毒物质;无论有无S9活化系统,霍山石斛类原球茎多糖各剂量组对鼠伤寒沙门菌株TA97、TA 98、TA 100、TA102无致突变作用;30d喂养期间,霍山石斛类原球茎多糖各剂量组对大鼠生长发育无不良影响。结论霍山石斛类原球茎对小鼠免疫调节活性的有效部位是多糖,其无毒,无致突变作用。     

中药复方藿莲香Ⅰ号的遗传毒理学研究

目的：根据前期藿莲香Ⅰ号药效学研究结果,进一步研究该复方的急性毒性和致突变作用,为其进一步应用的安全性提供理论依据。方法应用急性毒性实验、小鼠骨髓嗜多染红细胞微核试验、小鼠骨髓细胞染色体畸变试验和Ames试验检测该组分配伍复方的急性毒性和致突变性。结果急性经口毒性试验：雌性、雄性小鼠经口MTD均大于10g＆#183;kg-1,属实际无毒。致突变实验：小鼠骨髓嗜多染红细胞微核试验、小鼠骨髓细胞染色体畸变试验和Ames试验结果均为阴性,显示在本实验条件下,该中药复方未见有致突变性作用。结论中药复方藿莲香Ⅰ号未见有明显的急性毒性和致突变作用,表明该药物安全性良好。     

蛞蝓胶囊致畸和致突变实验研究

目的探讨蛞蝓胶囊是否具有致畸和致突变的毒理作用。方法本研究采用大鼠致畸胎、艾姆斯（Ames）试验、小鼠骨髓细胞微核试验、体外细胞染色体畸变试验检测的蛞蝓胶囊致畸胎、致突变性。结果蛞蝓胶囊各剂量对孕鼠体重、胚胎早期发育、胚胎生长发育、以及胎鼠的骨骼发育和内脏器官发育等均无不良影响。无论加与不加S9,各剂量组诱变TA98、TA100种菌落数均未超过自然回变菌落数,与阴性对照组比较均无显著性差异（P〉0．05）。与对照组相比,各剂量组对小鼠的微核率无明显的影响（P〉0．05）。蛞蝓胶囊对培养的哺乳动物体细胞染色体结构无致畸变作用。结论蛞蝓胶囊各剂量均无致畸和致突变的作用,说明在临床应用剂量范围内是安全的。     

Cytotoxic, mutagenic and genotoxic effects of new anti-T. cruzi 5-phenylethenylbenzofuroxans. Contribution of phase I metabolites on the mutagenicity induction

5-Phenylethenylbenzofuroxans have displayed in vitro and in vivo activity against Trypanosoma cruzi, the etiologic agent of American Trypanosomiasis. On the basis of benzofuroxans pre-clinical studies we evaluated the potential of six 5-phenylethenyl derivatives to induce cytotoxicity, mutagenicity and genotoxicity using different in vitro models. Cytotoxic effects were evaluated using a set of cells, mammal pre-monocytic macrophages, V-79 lung fibroblast from Chinese hamster, and colorectal adenocarcinoma Caco-2 cells, in the MTT viability assay. Mutagenicity was tested in the Ames assay using Salmonella typhimurium TA98 strain with and without metabolic activation by S9-rat liver homogenate. The genotoxic potentials were evaluated with the alkaline single cell gel electrophoresis (comet assay) in V-79 cells. In view of the Ames test results we study whether the main mammals’ phase I metabolites, the corresponding o-nitroanilines, are involved in the mechanism of mutagenicity. These metabolites are produced by NADPH-dependent enzymes in cytosol and by xanthine oxidase and cytochrome P450 in microsomes from rat liver. Among them, the electronic property of phenyl substituent seems to be responsible for this effect. It could be pointed out that the equimolecular mixture of compounds 1 and 2 (5E- and 5Z-(2-phenylethenyl)benzofuroxan, respectively) could be used in further clinical studies as anti-T. cruzi drug.     

Safety assessment of a wheat bran extract containing arabinoxylan-oligosaccharides: mutagenicity, clastogenicity, and 90-day rat-feeding studies

Wheat bran extract (WBE) is a food-grade preparation that is highly enriched in arabinoxylan-oligosaccharides. As part of the safety evaluation of WBE, its genotoxic potential was assessed in a bacterial reverse mutagenicity assay (Ames test) and a chromosome aberration assay on Chinese hamster lung fibroblast cells. These in vitro genotoxicity assays showed no evidence of mutagenic or clastogenic activity with WBE. The safety of WBE was furthermore evaluated in a subchronic toxicity study on rats that were fed a semisynthetic diet (AIN 93G) containing 0.3%, 1.5%, or 7.5% WBE for 13 weeks, corresponding to an average intake of 0.2, 0.9, and 4.4 g/kg body weight (bw) per day, with control groups receiving the unsupplemented AIN 93G, AIN 93G with 7.5% inulin, or AIN 93G with 7.5% wheat bran. Based on this rat-feeding study, the no-observed-adverse-effect level (NOAEL) for WBE was determined as 4.4 g/kg (bw)/d, the highest dose tested.     

Biological and chemical studies on overheated brewed coffee

Vapour formed from overheated decaffeinated coffee was condensed and tested for mutagenicity using the Ames assay in Salmonella typhimurium strains TA98 and TA100. Vapour produced at 73 and 100 degrees C exhibited no mutagenicity. The basic fraction of vapour produced at 350 degrees C showed weak mutagenicity towards strains TA98 with metabolic activation. The chemical analysis of this fraction identified pyridines and pyrazines as the major constituents. None of the compounds identified in this fraction has been reported as mutagenic when tested in the Ames assay.     

Mutagens from the cooking of food. II. Survey by Ames/Salmonella test of mutagen formation in the major protein-rich foods of the American diet

The formation of mutagens in the major cooked protein-rich foods in the US diet was studied in the Ames Salmonella typhimurium test. The nine protein-rich foods most commonly eaten in the USA—ground beef, beef steak, eggs, pork chops, fried chicken, pot-roasted beef, ham, roast beef and bacon—were examined for their mutagenicity towards S. typhimurium TA1538 after normal ‘household’ cooking (deep frying, griddle/pan frying, baking/roasting, broiling, stewing, braising or boiling at 100–475°C). Well-done fried ground beef, beef steak, ham, pork chops and bacon showed significant mutagen formation. For chicken and beef steak high-temperature broiling produced the most mutagenicity, followed by baking/roasting and frying. Stewing, braising and deep frying produced little mutagen. Eggs and egg products produced mutagens only after cooking at high temperatures (the yolk to a greater extent than the white). Commercially cooked hamburgers showed a wide range of mutagenic activity. We conclude that mutagen formation following cooking of protein-containing foods is a complex function of food type, cooking time and cooking temperature. It seems clear that all the major protein-rich foods if cooked to a well-done state on the griddle (eggs only at temperatures above 225°C) or by broiling will contain mutagens detectable by the Ames/Salmonella assay. This survey is a step towards determining whether any human health hazard results from cooking protein-rich foods. Further testing in both short- and long-term genotoxicity bioassays and carcinogenesis assays are needed before any human risk extrapolations can be made.     

An evaluation of the sensitivity of the Ames assay to discern low-level mutagenic impurities

Low level impurities often reside in active pharmaceutical ingredients (API). Some of these impurities are potentially genotoxic since reactive intermediates are used in the synthetic route for the production of API. Routine mutagenicity testing is conducted in support of clinical trials with the intent to identify genotoxic hazards associated with API. Depending on the amount of impurity present in the API tested, the potency of the impurities and the relative sensitivity of the Ames assay, it is possible that mutagenicity associated with the presence of genotoxic impurities could also be detected while testing API. Therefore, we evaluated published data and generated new information to understand the sensitivity of the Ames assay. Based on a literature survey of approximately 450 mutagens, it was estimated that 85% of mutagens are detected at concentrations of 250 microg/plate or less. Based on this estimate, most mutagens should be detected in an Ames assay testing API concentrations up to 5000 microg/plate if present at a 5% or greater concentration. Data from experiments where several direct and indirect-acting mutagens were spiked into representative API further support the literature-based evaluation. Some limitations of this approach, including toxicity of API and competing metabolism are discussed.     

Mutagenicity testing in the Salmonella typhimurium assay of phenolic compounds and phenolic fractions obtained from smokehouse smoke condensates

Smokehouse smoke, which is used for flavouring meat products, was investigated for its mutagenic activity in the Salmonella typhimturium assay. We chiefly concerned with the fractions free of polycyclic aromatic hydrocarbons but containing phenol compounds, which are responsible for the preservative and aromatizing properties of the smoke. The most abundantly occurring phenol compounds (phenol, cresols, 2,4-dimethylphenol, brenzcatechine, syringol, eugenol, vanilline and guaiacol) gave negative results when they were tested for mutagenicity at five concentrations up to 5000 μg/plate, with and without S-9 mix, using five strains of S. typhimurium. Even when phenol was further investigated in a variety of test conditions, no induction of his⁺ revertants was observed. When smokehouse smoke was condensed and fractionated the majority of the various phenolic fractions also gave negative results when tested at five concentrations using five strains of S. typhimurium. However there was a slight increase in the number of revertants in a few cases. The presence in the phenolic fractions of very small amounts of mutagenic impurities, the nature of which needs further investigation, cannot be excluded. These results support the further development of non-hazardous smoke-aroma preparations, based on the phenolic components of smokehouse smoke.