Mutagenicity testing of quinine with submammalian and mammalian systems

Quinine hydrochloride was assayed for genotoxic activity by using 4 different test systems with distinct genetic endpoints. No indications for point mutations were observed in the Ames system. In 3 cytogenetic tests performed on small rodents, Chinese hamsters showed no genotoxic activity, while inbred strains of mice revealed a dose dependent increase of SCEs, enhanced incidence of micronuclei and elevated chromatid breaks.     

The Cytogenetic Effects of Food Sweetener Maltitol in Human Peripheral Lymphocytes

The effects of the low-calorie artifical sweetener maltitol (E965), a sugar alcohol (Polyol), on sister chromatid exchange (SCE), chromosome aberration (CA), and micronucleus formation (MN) were investigated in human peripheral lymphocytes. Maltitol did not induce SCE at all concentrations (1.25, 2.5, and 5 mg/mL) and treatment periods (24 and 48 h). Maltitol induced CA, although not statistically significantly. Maltitol induced the frequency of MN at 24 and 48 h in a non-dose-dependent manner. In addition, maltitol did not decrease the replication index (RI) and the mitotic index (MI) at all concentrations and treatment periods. Maltitol did not alter the pH and osmolality of the medium. In conclusion, it can be concluded that maltitol has a weak genotoxic potential and it appears non-cytotoxic to human peripheral lymphocytes in vitro.     

Genotoxicity of benomyl and its residues in somatic and germ cells of mice fed on treated stored wheat grains

Swiss mice were fed for 2, 4 and 8 weeks wheat grains treated with 1, 2, and 4 g benomyl/kg and stored for 6 and 12 weeks. The maximum effect of benomyl on the induction of chromosomal aberrations was observed after feeding mice for 8 weeks with wheat grains treated with 4 g benomyl/kg and stored for 12 weeks. Its proportion differed significantly in bone marrow and spermatocyte cells, 15±0.51% vs. 13.4±0.66%, respectively, from that in nontreated mice (background level), 4.4±0.24% and 3.8±0.20%, respectively. Lengthening the storage period of treated wheat grains caused a dose-dependent increase in the frequency of sister chromatid exchanges: 8.61±0.34 vs. 4.16±0.06/cell. The proportion of sperm-head abnormalities increased by lengthening the period of storage and feeding: 7.7±0.41% vs. 3.25±0.12%. In another experiment mice were orally treated by gavage with benomyl at 50, 100, 150, 200 mg/kg; a significant and dose-dependent increase in sperm-head abnormalities was observed. These findings demonstrate that benomyl (a 50% wettable powder formulation) and its residues in wheat grains are genotoxic in mice.     

Evaluation of teratogenicity and genotoxicity induced by kramecyne (KACY)

Kramecyne (KACY), a polymer isolated from Krameria cytisoides Cav, has anti-inflammatory, anti-nociceptive, anti-arthritic and anti-ulcerogenic properties. As a part of standard preclinical safety tests, the present study sought to determine potential developmental toxicity (in female rats) and genotoxicity (in male mice) of KACY. Pregnant female rats were divided into six groups: the negative control (vehicle), the positive control (250?mg/kg of acetylsalicylic acid (ASA)), and four experimental groups (50, 250, 500 and 1000?mg/kg of KACY). To evaluate genotoxicity by in vivo micronuclei (MN) and sister chromatid exchange (SCE) tests, male mice were divided into five groups: the negative control (vehicle), the positive control (1.5 and 2.5?mg/kg of doxorubicin for MN and SCE, respectively), and three experimental groups (50, 500 and 1000?mg/kg of KACY). All treatments were administered by oral gavage. A slight maternal toxicity was evidenced by lower weight gain for rats receiving 500 and 1000?mg/kg of KACY, but no fetal malformations were found. However, there were less live fetuses/litter and greater post-implantation loss/litter at these two doses. Manifestations of developmental toxicity were limited to a higher rate of skeletal alterations. The MN tests did not evidence genotoxicity or cytotoxicity. KACY caused a slightly but significantly increased frequency of SCE. Although KACY-treated rats had skeletal alterations, these apparently were not caused by a mechanism of genotoxicity. Furthermore, the same administration in adult male mice did not produce genotoxicity. Hence, KACY herein proved to be safe for rats during the period of organogenesis.     

Genotoxicity of titanium dioxide nanoparticles

Titanium dioxide nanoparticles (TiO₂-NPs, <100 nm) are increasingly being used in pharmaceuticals and cosmetics due to the unique properties derived from their small sizes. However, their large surface-area to mass ratio and high redox potential may negatively impact human health and the environment. TiO₂-NPs can cause inflammation, pulmonary damage, fibrosis, and lung tumors and they are possibly carcinogenic to humans. Because cancer is a disease involving mutation, there are a large number of studies on the genotoxicity of TiO₂-NPs. In this article, we review the results that have been reported in the literature, with a focus on data generated from the standard genotoxicity assays. The data include genotoxicity results from the Ames test, in vitro and in vivo Comet assay, in vitro and in vivo micronucleus assay, sister chromatid exchange assay, mammalian cell hypoxanthine-guanine phosphoribosyl transferase gene assay, the wing somatic mutation and recombination assay, and the mouse phosphatidylinositol glycan, class A gene assay. Inconsistent results have been found in these assays, with both positive and negative responses being reported. The in vitro systems for assessing the genotoxicity of TiO₂-NPs have generated a greater number of positive results than the in vivo systems, and tests for DNA and chromosome damage have produced more positive results than the assays measuring gene mutation. Nearly all tests for measuring the mutagenicity of TiO₂-NPs were negative. The current data indicate that the genotoxicity of TiO₂-NPs is mediated mainly through the generation of oxidative stress in cells.     

Genotoxicity of multi-walled carbon nanotubes in both in vitro and in vivo assay systems

Abstract

The genotoxic effects of multi-walled carbon nanotubes (MWCNTs) were examined by using in vitro and in vivo assays. MWCNTs significantly induced micronuclei in A549 cells and enhanced the frequency of sister chromatid exchange (SCE) in CHO AA8 cells. When ICR mice were intratracheally instilled with a single dose (0.05 or 0.2 mg/animal) of MWCNTs, DNA damage of the lungs, analysed by comet assay, increased in a dose-dependent manner. Moreover, DNA oxidative damage, indicated by 8-oxo-7,8-dihydro-2′-deoxyguanosine and heptanone etheno-deoxyribonucleosides, occurred in the lungs of MWCNT-exposed mice. The gpt mutation frequencies significantly increased in the lungs of MWCNT-treated gpt delta transgenic mice. Transversions were predominant, and G:C to C:G was clearly increased by MWCNTs. Moreover, many regions immunohistochemically stained for inducible NO synthase and nitrotyrosine were observed in the lungs of MWCNT-exposed mice. Overall, MWCNTs were shown to be genotoxic both in in vitro and in vivo tests; the mechanisms probably involve oxidative stress and inflammatory responses.     

Effects of natamycin on sister chromatid exchanges,chromosome aberrations and micronucleus in human lymphocytes

Natamycin (pimaricin) (E235) is an antifungal that can be used as an antibiotic to treat most fungus infections. It has been globally used in a variety of foods and beverages. In the present study, the effects of natamycin on chromosome aberrations (CAs), sister chromatid exchanges (SCEs), and micronucleus (MN) formation in human lymphocytes cells were investigated. The human lymphocytes were treated with 13, 18, 23, and 28 μg/mL of natamycin for 24 and 48 h. Natamycin induced the SCE frequency at the highest concentration for 48 h only; however, it induced the structural CA and MN frequency at all concentrations when compared to control and at all concentrations, except the lowest concentration (13 μg/mL), when compared to solvent control. Natamycin showed a cytotoxic effect by decreasing the replication index, mitotic index, and nuclear division index (NDI), especially at the highest concentrations for two treatment periods.     

The Effects of Food Protector Biphenyl on Sister Chromatid Exchange,Chromosome Aberrations,and Micronucleus in Human Lymphocytes

The aim of this study was to determine the possible genotoxic effects of biphenyl (E230), which is used as an antimicrobial agent in food by using sister chromatid exchanges (SCEs), chromosome aberrations (CAs), and micronucleus (MN) tests in human peripheral lymphocytes. The human peripheral lymphocytes were treated with four concentrations of biphenyl (10, 30, 50, and 70 μg/mL) for 24- and 48-h treatment periods. In the present study, biphenyl significantly increased the frequency of SCEs, CAs, and the frequency of MN when compared with both untreated control and solvent (dimethyl sulfoxide) control. The inductions of these abnormalities were in a dose-dependent manner. Biphenyl was capable to induce the structural CAs instead of numerical CAs. Biphenyl also showed a cytotoxic effect by decreasing the replication index at the highest two concentrations for 48 h and nuclear division index at the highest two concentrations for the 24- and 48-h treatment periods. However, biphenyl did not affect the mitotic index (MI).     

Assessment of micronuclei and sister chromatid exchange frequency in the petroleum industry workers in province of Vojvodina,Republic of Serbia

Persons who work with petroleum and petroleum derivatives (PPD) are potentially at risk of developing cancer mostly due to the carcinogenity of benzene. Therefore, the aim of this study was to determine in which degree occupational exposure of workers to PPD causes damage to DNA by analysis of micronuclei (MN), sister chromatid exchanges (SCE) and proliferation index (PI). 30 workers of refinery in Novi Sad, participated in the study as exposed and 30 volunteers as control group. Workers exposed to PPD had significantly higher values of MN and SCE in comparison to controls. Exposition time to PPD and type of working place have also significantly effects to DNA damage. The influence of confounding factor such as smoking and age were also evaluated.     

妊高征母血、脐血染色体稳定性和内皮素变化的研究

目的 在致妊高征(PIH)众多因素中,观察PIH孕妇外用血及其脐血姐妹染色单体互换(SCE)频率和内皮素(ET)的变化及其两者的关系,以资探讨PIH的病因和提高PIH的监测水平。方法 采用SCE法和放免法分别对21例PIH病人和15例正常孕妇(对照组)的外周血及其所分娩新生儿脐血SCE频率及其ET进行测定。结果 PIH组外周血和脐血SCE频率分别为6.11±1.29,5.98±1.38;对照组外周血和脐血SCE频率分别为3.45±O.71,3.16±0.57,其两组比较,差异有极显著性(P<0.001)。PIH组外用血和脐血SCE频率皆异常。PIH组外用血ET含量的均值(51.87±24.72pg/ml)明显低于其脐血的均值(63.65±27.63pg/ml),两者比较差异有显著性(P<0.05)。两组SCE和ET相关性分析无明显相关性(r=0.092,P>0.05)。结论 PIH与遗传物质DNA损伤有关,SCE频率可作为一项诊断、预测PIH的重要指标。PIH孕妇脐血ET增高有助于PIH发病机理的揭示。     

荷人脑瘤裸小鼠模型(NHG-1)的活体骨髓细胞 SCE 及染色体畸变分析

采用改良的Perdo方法测定人脑恶性胶质瘤裸小鼠模型(NHG-1)和NC 系正常裸小鼠活体骨髓细胞的SCE,结果提示NHG-1的SCE 值(2.47±0.15)显著高于正常鼠(1.78±0.14)。NHG-1和NC 系正常裸小鼠活体骨髓细胞染色体畸变测定,结果形态异常与正常鼠相近,而染色体计数异常(18.5±44)显著高于NC 系正常鼠(5.4±2.5)。说明SCE 及染色体计数异常频率增高,是NHG-1的重要染色体特征;并为人脑恶性胶质瘤的细胞遗传学研究积累了资料。     

天冬天精的合成

本文通过全新的合成路线,以L-苯丙氨酸为起始化合物,经过甲酯化、游离、成内酐、缩合、水解、精制等6步反应得到天冬天精,总收率达到45．85％,较文献收率提高了8％,质量符合标准。     

Cytogenetic Evaluation of Paracetamol Effects in Human Lymphocytes Culture

Paracetamol is a common analgesic and antipyretic drug. It has been recognized as one of the most ordinary medications taken in overdoses. We examined the possible genotoxic effects of high paracetamol concentrations expected to occur after overdose. Paracetamol was added to the cultures at the beginning of the cultivation period. Separate cultures for three tested concentrations of paracetamol (50 μg/mL, 100 μg/mL, and 200 μg/mL) were set. Effects of paracetamol were evaluated by micronucleus cytokinesis-block assay, chromosome aberration analysis, and nuclear division index. Results demonstrate that paracetamol concentration of 200 μg/mL expresses certain genotoxic effects in human peripheral blood lymphocytes.     

Genotoxicity analysis of the phenoxy herbicide dicamba in mammalian cells in vitro

The cytogenetic effects exerted by the phenoxy herbicide dicamba and one of its commercial formulations banvel^® (57.71% dicamba) were studied in in vitro whole blood human lymphocyte cultures. The genotoxicity of herbicides was measured by analysis of the frequency of sister chromatid exchanges (SCEs) and cell-cycle progression assays. Both dicamba and banvel^® activities were tested within 10.0–500.0 μg/ml doses range. Only concentrations of 200.0 μg/ml of dicamba and 500.0 μg/ml of banvel^® induced a significant increase in SCE frequency over control values. The highest dose of dicamba tested (500.0 μg/ml) resulted in cell culture cytotoxicity. The cell-cycle kinetics was affected by both test compounds since a significant delay in cell-cycle progression and a significant reduction of the proliferative rate index were observed after the treatment with 100.0 and 200.0 μg/ml of dicamba and 200.0 and 500.0 μg/ml of banvel^®. For both chemicals, a progressive dose-related inhibition of the mitotic activity of cultures was observed. Moreover, only the mitotic activity statistically differed from control values when doses of both chemicals higher than 100.0 μg/ml were employed. On the basis of our results, the herbicide dicamba is a DNA damage agent and should be considered as a potentially hazardous compound to humans.     

氟哌啶醇对人体淋巴细胞SCE频率的影响

本文研究抗精神病药物氟哌啶醇对离体培养的人体淋巴细胞的SCE频率影响的效应。并与对照组进行比较,差异“不显著”。     

雷公藤内酯醇的遗传毒性评价

目的 观察雷公藤的主要有效成分之一雷公藤内酯醇的遗传毒性。方法 采用鼠伤寒沙门氏菌回复突变试验(Ames试验)、体外培养CHO细胞染色体畸变试验和小鼠骨髓微核试验检测雷公藤内酯醇的遗传毒性。结果 Ames试验提示在每皿1.6~1000 μg受试剂量下,在加或不加S9代谢活化系统时,受试物对组氨酸缺陷型鼠伤寒沙门氏菌TA97、TA98、TA100、TA102及TA1535所诱发的回复突变菌落数均与溶媒对照的突变菌落数相近。体外培养CHO细胞染色体畸变试验结果显示0.01、0.02和0.04 μg/ml 3个剂量的受试物,对加与不加S9代谢活化系统培养的CHO细胞的染色体畸变率无明显影响。小鼠骨髓微核试验设180、360、720 μg/kg 3个剂量,在720 μg/kg剂量时,雷公藤内酯醇有诱发骨髓嗜多染红细胞微核率增高的效应。结论 在本实验条件下,雷公藤内酯醇对鼠伤寒沙门氏菌无致突变性,对哺乳动物培养细胞染色体无致畸变作用,720 μg/kg剂量下对ICR小鼠有诱发骨髓嗜多染红细胞微核率增高的效应。提示雷公藤内酯醇对人体可能具有潜在的遗传毒性。     

Evaluation of the cyto/genotoxicity profile of oxime K048 using human peripheral blood lymphocytes: An introductory study

This study investigates the effects of oxime K048 (730, 200, and 7.3 nM) on the viability and chromosome stability of human peripheral blood lymphocytes (PBLs) after a 30 min exposure in vitro. Cytotoxicity was tested by a viability assay with ethidium bromide and acridine orange. For the evaluation of the genotoxic potential, we used comet assays, cytokinesis-blocked micronucleus (CBMN) assay, and chromosome aberration (CA) analysis. We found acceptable cytotoxicity for K048 (9.7 ± 2.1% non-viable PBL at highest concentration vs. 7.3 ± 2.5% in control; apoptosis dominated over necrosis). Overall primary DNA damage was low and not significantly different from controls. The hOGG1-comet assay showed a slight increase in the level of oxidative DNA damage. In oxime treated PBLs, we found 13–19 MN compared to 15 MN in control cultures. The frequencies and types of CA in oxime-treated PBLs did not significantly differ from controls. K048 showed acceptable biocompatibility at the level of cell viability and chromatin/chromosome integrity. Since no increase in secondary genome damage was detected, the primary DNA lesions may have resulted from treatment-induced cell stress, subsequently becoming repaired and not fixed as chromosome aberrations. The toxicity profile of K048 should be further studied and compared with other clinically relevant oximes.     

胃癌患者外周血淋巴细胞微核,姊妹染色单体互换及染色体畸变的观察

对16例胃癌患者和16例正常健康人的外周血淋巴细胞的微核、姊妹染色单体互换(SCE)以及染色体畸变进行了观察和比较。结果发现,正常健康人和患者的微核率分别为0.053％和0.197％;SCE频率均值为6.34±0.46和10.17±1.24;染色体畸变率分别为2.71％和6.67％。胃癌患者均高于正常健康人,且有显著性差异。表明胃癌的发生与染色体不稳定性及DNA修复能力有关。     

Wentilactone A的遗传毒性评价

目的 检测Wentilactone A的遗传毒性。方法 应用经典遗传毒性检测组合(Ames试验、体外培养CHO细胞染色体畸变试验和小鼠骨髓微核试验)检测Wentilactone A的遗传毒性。结果 Ames试验结果提示,Wentilactone A在每皿5 000、500、50、5、0.5 μg 5个剂量下,在加和不加代谢活化系统（S9）时,对鼠伤寒沙门菌均无致突变性。CHO细胞染色体畸变试验结果提示,在终浓度23.74、47.48、94.96 μg/ml 3个剂量组,在加和不加S9中,于作用4 h和24 h的条件下培养的CHO细胞,均未诱发染色体畸变。小鼠骨髓微核试验在100、200、400 mg/kg 3个剂量下作用24 h以及400 mg/kg剂量下作用48 h对骨髓细胞的微核诱发率,与溶剂对照组比较均无显著差异（P>0.05）。结论 Wentilactone A对鼠伤寒沙门菌无致突变性,对CHO细胞的染色体无致畸变作用,对ICR小鼠无诱发骨髓细胞微核的效应。上述结果提示Wentilactone A不具有遗传毒性和潜在致癌性。     

Genotoxicity and antileishmanial activity evaluation of Physalis angulata concentrated ethanolic extract

Antileishmanial in vitro tests, as well as Ames and micronucleus assays were performed with a concentrated ethanolic extract of Physalis angulata (EEPA)ResultsEEPA did not present mutagenic effect in Salmonella typhimurium strains at concentration reaching 3000 μg/plate and did not induce mutagenic effects after two oral administrations with a 24 h interval at a dose level of 2000 mg/kg. EEPA presented antileishmanial activity and presented an IC₅₀ value of 5.35 ± 2.50 μg/mL and 4.50 ± 1.17 μg/mL against Leishmania amazonensis and Leishmania braziliensis promastigotes, respectively. In the cytotoxicity test against macrophages, the EEPA had a LC₅₀ of 6.14 ± 0.59 μg/mL. Importantly, the IC₅₀ against L. amazonensis intracellular amastigotes was 1.23 ± 0.11 μg/mL.ConclusionEEPA extract is non-mutagenic and presented a promising pharmacological effect against Leishmania parasites.