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Ames Test (Ame + test)
Selected AbstractsBacterial and mammalian-cell genotoxicity of mixtures of chlorohydroxyfuranones, by-products of water chlorinationENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 4 2004Jorma Mäki-Paakkanen Abstract The genotoxic responses of mixtures of four chlorohydroxyfuranones (CHFs), 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX), 3,4-dichloro-5-hydroxy-2(5H)-furanone (MCA), 3-chloro- 4-(chloromethyl)-5-hydroxy-2(5H)-furanone (CMCF) and 3-chloro-4-methyl-5-hydroxy-2(5H)-furanone (MCF), were compared with the genotoxicity of the individual compounds. Genotoxicity was evaluated in the Salmonella reversion assay (Ames test), the in vitro Chinese hamster ovary (CHO) cell Hprt mutation assay, and in the CHO chromosome aberration test. When tested individually, the concentrations of the chemicals that were chosen for the mixtures induced no or only a modest increase in the genotoxic effects, and caused little or no cytotoxicity. In the Ames test, the genotoxic responses caused by the mixtures of CHFs did not follow simple additivity. Synergism was observed with strains TA97 and TA98, and antagonism with strain TA100. In the CHO/Hprt mutation assay, the mutagenic response of the mixtures was inconsistent, with near additivity seen with a mixture of CHFs that resulted in 12% cell survival. In contrast, the four CHFs together consistently caused more structural chromosome damage (mainly chromatid-type breaks and exchanges) compared to the sum of net effects of the four CHFs tested alone. Also, a potentiating effect was consistently seen for the cytotoxicity of the CHF mixtures both in the CHO/Hprt mutation assay and the chromosome aberration test. The present results indicate that the genotoxic effects of CHF mixtures can be greater than additive. Such effects may be worth considering in the cancer risk assessment of chlorinated drinking water. Environ. Mol. Mutagen. 43:217,225, 2004. © 2004 Wiley-Liss, Inc. [source] Mutagenicity of nitroaromatic degradation compoundsENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 10 2003Ranjit S. Padda Abstract The mutagenicity of 2,4-dinitrotoluene (24DNT), and 2,6-dinitrotoluene (26DNT), and their related transformation products such as hydroxylamine and amine derivatives, which are formed by Clostridium acetobutylicum, were tested in crude cell extracts using Salmonella typhimurium TA100. A previous publication already reported the mutagenic activities of 2,4,6-trinitrotoluene (TNT) and its related hydroxylamine derivatives in this test system. A time course of the mutagenicity during the anaerobic transformation of TNT, 24DNT, and 26DNT was also investigated under the same conditions to compare with the results from the pure compounds. The monohydroxylamino intermediates 2-hydroxylamino-4-nitrotoluene (2HA4NT), 4-hydroxylamino-2-nitrotoluene (4HA2NT) and 2-hydroxylamino-6-nitrotoluene (2HA6NT) formed during anaerobic transformation of dinitrotoluenes were proven to be mutagenic in the Ames test using Salmonella typhimurium TA100. This study reports that 4HA2NT is the most stable derivative, whereas 2HA4NT and 2HA6NT are less stable and these intermediates are mutagenic in the Ames test. Both 24DNT and 26DNT and their final metabolites 2,4-diaminotoluene (24DAT) and 2,6-aminotoluene (26DAT) appeared nonmutagenic. In a time-course study of TNT degradation, the temporal sample containing 85% of 2,4-dihydroxylamino-6-nitrotoluene (24HA6NT) is most mutagenic. These observations suggest that the bioremediation approach for treatment of 24DNT and 26DNT should be carried past the hydroxylamino intermediate. [source] Cytotoxicity of settling particulate matter and sediments of the Neckar River (Germany) during a winter floodENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 3 2000Henner Hollert Abstract To investigate the cytotoxic and genotoxic potentials of settling particulate matter (SPM) carried by the Neckar River, a well-studied model for a lock-regulated river in central Europe, during a flood, acute cytotoxicity was investigated using the fibroblast-like fish cell line RTG-2 with the neutral red retention, the succinic acid dehydrogenase (MTT), and the lactatedehydro-genase (LDH) release assays as well as microscopic inspection as endpoints. Genotoxicity of water, pore water, sediments, and SPM were assessed using the Ames test. Different extraction methods (Soxhlet extraction with solvents of variable polarity as well as a fluid/fluid extraction according to pH) in addition to a supplementation of biotests with S9 fractions from the liver of ,-naphthoflavone/phenobarbital-induced rats allowed a further characterization of the biological damage. Both sediments and SPM extracts caused cytotoxic effects in RTG-2 cells. Cytotoxicity was found to increase significantly with polarity of extracting solvents (NR50 = effective concentration for 50% cell death in the neutral red test: 80 [65], 100 [70], 180 [220], and 225 [270] mg/ml for ethanol, acetone, dichloromethane, and n -hexane extracts, respectively, if measured with [without] S9 supplementation). Following extraction according to pH, cytotoxicity could be attributed mainly to neutral substances (NR50: 80 and 218 mg dry SPM/ml test medium for the neutral and the acid fractions, respectively), whereas the slightly acid and basic fractions already showed little or no cytotoxicity. Samples taken during the period of flood rise showed the highest cytotoxic activities. Cytotoxicity was significantly enhanced by the addition of S9 preparations. In contrast, no genotoxic activity was found in native surface waters, pore waters, and SPM. [source] Mutagenic Safety and Fatty Liver Improvement of Nanonized Black Soybeans in Senescence-Accelerated Prone-8 MiceJOURNAL OF FOOD SCIENCE, Issue 5 2010J.-W. Liao Abstract:, Nanotechnology, as a new enabling technology, has the potential to revolutionize food systems. However, much attention has been focused on nanoparticle foods due to their potential physiological properties. This study was aimed to evaluate the mutagenic safety and fatty liver improvement of black soybean in senescence-accelerated mice (SAMP8). The mutagenic activity of black soybeans was investigated using the Ames test (Salmonella Typhimurium,TA98, 100, 102, and 1535). Furthermore, senescence-accelerated prone-8 mice (SAMP8) have been reported to display spontaneous fatty liver. Male SAMP8 mice were divided into control and supplemented with 10% micronized or nanonized black soybeans diet and fed for 12 wk. The results revealed that the Ames test of micronized and nanonized black soybeans exhibited no mutagenicity. Administration of black soybeans to mice showed no effects on food intake and body and organ weights. The nanonized black soybean group had a lower degree of spontaneous fatty liver, alanine aminotransferase, and thiobarbituric acid-reactive substance concentrations, and had enhanced superoxide dismutase, catalase, and glutathione peroxidase activities of livers when compared with the SAMP8 control and micronized black soybean groups. The mice fed with black soybeans had significantly lower triglyceride concentrations than the SAMP8 control group. The results of this study suggest that nanonized black soybeans have no side effects and, moreover, may minimize liver lesions in SAMP8 mice. [source] Mutagenicity and Safety Evaluation of Water Extract of,Coriander sativum,LeavesJOURNAL OF FOOD SCIENCE, Issue 1 2010Mariana Ramírez Reyes ABSTRACT:, Coriander has been used as a spice and medicinal plant for centuries. Several studies have described its biological properties and some reports have indicated its pharmacological actions in some human pathology. However, data on its toxicity and metabolism are limited or null, and no research has been conducted with mammalian cells. The purpose of this study was to evaluate the mutagenicity and safety of,Coriandrum sativum,extract. The mutagenic effects of,C. sativum,extract were evaluated by Ames test. Mutagenicity was present when the,C. sativum,extract was used in high concentrations in both tested strains (Salmonella typhimurium,TA97 and TA102). Our research showed that,C. sativum,extract reduced the cell survival of human cell lines (WRL-68 and 293Q cells) by inducing apoptosis and necrosis in the cases where extract concentration was the highest. The,C. sativum,extract altered the cell cycle; it increased the G1 phase of hepatic cells and reduced the G2+M phase in both cell lines in a dose-response manner. These results showed correlation with a reduction in the mitotic index. The extract also induced severe malformations during embryonic development. Exposure of chicken embryos to the,C. sativum,extract resulted in a dose-dependent increase of anomalies. Present results show that,C. sativum,extract reduced the axial skeleton and affected the neural tube, the somites, the cardiovascular structures, and the eye. According to the present results, the,C. sativum,aqueous extract cannot be considered safe. These results indicate that some significant adverse effects of,C. sativum,extract could be observed,in vivo. [source] Absence of mutagenic effects of a particular Symphytum officinale L. liquid extract in the bacterial reverse mutation assayPHYTOTHERAPY RESEARCH, Issue 3 2010Birgit Benedek Abstract Comfrey (Symphytum officinale L.) root is traditionally used for the topical treatment of contusions, strains and sprains. Besides allantoin and rosmarinic acid, which are discussed as pharmacologically active principles, the drug contains pyrrolizidine alkaloids (PAs) known for their hepatotoxic, carcinogenic and mutagenic properties. The topical herbal medicinal products Kytta-Salbe® f and Kytta-Plasma® f contain a PA-free liquid extract from comfrey root as active substance. The aim of this study was to demonstrate the absence of genotoxic effects of this special extract in the bacterial reverse mutation assay (Ames test). Briefly, comfrey root liquid extract was investigated for its ability to induce gene mutations in Salmonella typhimurium strains TA 98, TA 100, TA 102, TA 1535 and TA 1537 with and without metabolic activation using the mammalian microsomal fraction S9 mix. Reference mutagens were used to check the validity of the experiments. Comfrey root fluid extract showed no biologically relevant increases in revertant colony numbers of any of the five tester strains, neither in the presence nor in the absence of metabolic activation. In conclusion, the comfrey root fluid extract contained in Kytta-Salbe® f and Kytta-Plasma® f was not mutagenic in the bacterial reverse mutation assay. Copyright © 2009 John Wiley & Sons, Ltd. [source] Inhibitory effect of magnolol on Trp-P-2-induced DNA damage in various organs in micePHYTOTHERAPY RESEARCH, Issue 7 2009Junichiro Saito Abstract Magnolol has been reported to strongly inhibit the mutagenicity induced by indirect mutagens in the Ames test as well as the clastogenicity induced by benzo(a)pyrene (B(a)P) in the mice micronucleus test. Here, we evaluated the inhibitory effect of magnolol on the DNA damage induced by 3-amino-1-methyl-5H -pyrido[4,3-b]indole (Trp-P-2) in various organs using the mice alkaline single cell gel electrophoresis (SCG) assay. Animals were treated with a single oral administration of magnolol (0.01, 0.1, 1, 10, and 100 mg/kg), followed by a single intraperitoneal injection of Trp-P-2 (10 mg/kg). The liver, lung, and kidney were removed at 3 h after treatment and used in SCG assay. The results indicated that magnolol inhibited Trp-P-2-induced DNA damage in various organs. To elucidate the mechanism of this inhibitory effect against Trp-P-2, we investigated the inhibitory effect of magnolol on in vivo CYP1A2 activity using the zoxazolamine paralysis test. Magnolol significantly prolonged zoxazolamine paralysis time and showed an inhibitory effect on in vivo CYP1A2 activity. These results indicate that magnolol has an inhibitory effect on the DNA damage induced by Trp-P-2 in various organs in vivo. This inhibitory mechanism is considered due to in vivo CYP1A2 inhibition. Copyright © 2009 John Wiley & Sons, Ltd. [source] | ||||||||||