Showing papers on "Ames test published in 2009"
TL;DR: Results appear useful to extend the knowledge on the safety of carbon nanotubes in view of their possible applications and the limited background of genotoxicity studies and the increased occupational and public exposure to nanomaterials.
106 citations
TL;DR: There was 84% agreement between the two procedures in identifying mutagens and non-mutagens, which is equivalent to the intra- and interlaboratory reproducibility of 87% for the traditional test.
Abstract: The Ames II Salmonella mutagenicity assay procedure was used to test 71 chemicals, and the results were compared with those from the traditional Ames Salmonella test using the NTP database as the reference. All Ames II tests were performed using a fluctuation procedure in microplate format, using TAMix for the detection of base pair substitutions and TA98 to detect frameshift mutations. There was 84% agreement between the two procedures in identifying mutagens and non-mutagens, which is equivalent to the intra- and interlaboratory reproducibility of 87 % for the traditional test. The two tests also performed similarly in their predictions of rodent carcinogenicity.
91 citations
TL;DR: The Vitotox and RadarScreen assays were evaluated as early screens for mutagenicity and clastogenicity and validated with respect to a list of genotoxic and non-genotoxic chemicals that can be used for the validation and/or optimization of in vitro genotoxicity assays.
Abstract: The Vitotox and RadarScreen assays were evaluated as early screens for mutagenicity and clastogenicity, respectively. The Vitotox assay is a bacterial reporter assay in Salmonella typhimurium based on the SOS-response, and it contains a luciferase gene under control of the recN promoter. The RadarScreen assay is a RAD54 promoter-linked beta-galactosidase reporter assay in yeast. The expression of this beta-galactosidase can easily be quantified by use of the substrate d-luciferin-o-beta-galactopyranoside, which is converted into galactose and luciferin that can be measured luminometrically. Recently, an ECVAM workgroup defined a list of 20 genotoxic and 42 non-genotoxic compounds [D. Kirkland, P. Kasper, L. Muller, R. Corvi, G. Speit, Recommended lists of genotoxic and non-genotoxic chemicals for assessment of the performance of new or improved genotoxicity tests: a follow-up to an ECVAM workshop, Mutat. Res. 653 (2008) 99-108.] that can be used for the validation and/or optimization of in vitro genotoxicity assays. In the present study, this compound set was used for the validation of the assays. Moreover, an additional set of 192 compounds was used to broaden this validation study. The compounds of this additional set can be classified as non-genotoxins and genotoxins and consists of both in-house and reference compounds. In case of the ECVAM compound list, the results from the Vitotox and RadarScreen assays were compared to the genotoxic/non-genotoxic classification of the compounds in this list. In case of the additionally tested compounds, the results of the Vitotox and RadarScreen assays were compared, respectively, with bacterial mutagenicity (Ames) results or in vitro clastogenicity data obtained in-house or from the literature. The validation with respect to the ECVAM compound list resulted in a sensitivity for both the Vitotox and RadarScreen assay of 70% (14/20). If both assays were combined the sensitivity increased to 85% (17/20). Both tests also gave a low number of false positive results. The specificity of the Vitotox and RadarScreen assays was 93% (39/42) and 83% (35/42), respectively. This resulted in a predictivity of the Vitotox and RadarScreen assay of 85% (53/62) and 79% (49/62), respectively. In case both tests were combined the specificity and the predictivity of the Vitotox and RadarScreen assay turned out to be 81% (34/42) and 82% (51/62), respectively. The results from the additional list of 192 compounds confirmed the results found with the ECVAM compound list. The results from the Vitotox assay showed a high correlation with Ames test of 91% (132/145). Subsequently, the RadarScreen assay had a correlation with in vitro clastogenicity of 76% (93/123). The specificity of the Vitotox assay was 94% (90/96) for Ames test results and that of the RadarScreen assay was 74% (34/46) for clastogenicity. Moreover, the sensitivities of the Vitotox and RadarScreen assays were 86% (42/49) and 77% (59/77), respectively. Implementation of the Vitotox and RadarScreen assays in the early research phase of drug development can lead to fast de-selection for genotoxicity. It is expected that this application will reduce the number of compounds that have a positive score in the regulatory Ames and clastogenicity tests. Moreover, problems with a complete compound class can be foreseen at an early time point in the research phase, which gives more time for issue resolution than late detection of these problems with the regulatory tests.
73 citations
TL;DR: Genotoxic and mutagenic effects were especially found for one photoproduct suggesting that transformation products, as frequently demonstrated, may show effects higher than the respective parental compound.
68 citations
TL;DR: This study aimed to determine nicotine biodegradation and the genotoxic potential of nicotine and its degradation products during the process of tobacco waste composting and it was shown that the composts produced did not exhibit mutagenicity.
66 citations
TL;DR: Despite an apparent lack of genotoxic activity, enniatin B can exert biological activity at low micromolar concentrations in mammalian cells, as determined by neutral red uptake assay for 48 h exposure.
Abstract: Enniatin B, a fungal metabolite produced by various Fusarium strains, is a frequent contaminant in cereals used for human foods and animal feeds, but, so far very limited data are available on its toxicity. The aim of this study was to investigate the effects of enniatin B in a battery of short-term tests to evaluate its genotoxic potential. In Salmonella typhimurium assays (Ames assay) with the strains TA 98, TA 100, TA 102, and TA 104, both in the presence and absence of an external metabolizing enzyme system (rat liver S9), no mutagenicity was detected up to toxic levels (100 microM) of enniatin B. Likewise, mutagenicity tests in mammalian cells, i. e., the hypoxanthin-guanin-phosphoribosyl-transferase (HPRT) assay with V79 cells performed with and without S9 mix, did not reveal a significant increase in mutant frequency for enniatin B up to 30 microM, a cytotoxic concentration. Additional tests on other types of genotoxicity, i. e., clastogenicity and chromosomal damage, were conducted in V79 cells, applying the alkaline single cell gel electrophoresis (Comet assay with and without FPG, formamidopyrimidine DNA glycosylase, enzyme) and the micronucleus assay. None of these assays revealed a significant genotoxic potential of enniatin B. However, enniatin B exerts pronounced cytotoxic effects in V79 cells as determined by neutral red uptake assay for 48 h exposure: The IC(20) and IC(50) values of 1.5 and 4 microM, are higher than those of the more potent Fusarium toxin deoxynivalenol (IC(20) 0.6 microM, IC(50) of 0.8 microM), but in a similar range as values reported for cytotoxicity of enniatin B in various tumor cell lines. In summary, despite an apparent lack of genotoxic activity, enniatin B can exert biological activity at low micromolar concentrations in mammalian cells.
62 citations
TL;DR: A strengthened in vitro bioassay is able to describe a relevant role played by the nitro compounds in the mutagenic properties of the urban PM2.5 in the Padana plain; moreover the bacterial nitroreductase plays a predominant role in DNA interaction primarily for Torino PM1.5 extracts.
58 citations
TL;DR: Three of the medicinal plants altered at least three of the normal biochemical characteristics thus demonstrating mutagenic potentials, and the results of internationally accepted Allium cepa were comparable with the modified Ames test.
57 citations
TL;DR: It can be presumed that orally administered FX is a safe compound in terms of mutagenicity under the experimental conditions employed here.
Abstract: Mutagenicity of fucoxanthinol (FXOH), the major compound after oral ingestion of fucoxanthin (FX), was evaluated by in vitro Ames test, and of FX by in vivo micronucleus test. In in vitro Ames test, bacterial reverse mutation was examined by using Salmonella typhimurium strains TA98, TA100, TA1535 and TA1537, and Escherichia coli WP2uvrA/pKM101, with or without metabolic activation by S9 mix in the preincubation method, and mutagenicity of FXOH was found to be negative in all cases. In in vivo micronucleus test, mice were orally administered with FX at doses of 500, 1,000 and 2,000 mg/kg, and the bone marrow cells were taken 24 hr after the administration to observe the incidence of micronucleus cells, and mutagenicity of FX was found to be negative at all doses. Based on the data of the present study it can be presumed that orally administered FX is a safe compound in terms of mutagenicity under the experimental conditions employed here.
52 citations
TL;DR: A novel bioassay employing gene-disrupted clones of the chicken DT40 B-lymphocyte line designed to be deficient in several specific DNA repair pathways is developed, which is a reliable and sensitive screening tool for environmental mutagens as well as for characterizing the nature of detected genotoxicity.
Abstract: BackgroundMany bacterial or mammalian cell-based test systems, such as the Ames test, chromosomal aberration assays, or gene mutation assays, are commonly used in developed countries to detect the ...
51 citations
TL;DR: Reaction of BDA with N-acetylcysteine or GSH in the presence of lysine indicated that both the alpha- and the epsilon-amino groups ofLysine can be modified by thiol-BDA, suggesting that there are multiple pathways by which furan can modify cellular nucleophiles.
Abstract: Furan is a liver toxicant and carcinogen in rodents. On the basis of these observations and the large potential for human exposure, furan has been classified as a possible human carcinogen. The mechanism of tumor induction by furan is unknown. However, the toxicity requires cytochrome P450-catalyzed oxidation of furan. The product of this oxidation, cis-2-butene-1,4-dial (BDA), reacts readily with glutathione, amino acids, and DNA and is a bacterial mutagen in Ames assay strain TA104. Characterization of the urinary metabolites of furan is expected to provide information regarding the structure(s) of the reactive metabolite(s). Recently, several urinary metabolites have been identified. We reported the presence of a monoglutathione-BDA reaction product, N-[4-carboxy-4-(3-mercapto-1H-pyrrol-1-yl)-1-oxobutyl]-l-cysteinylglycine cyclic sulfide. Three additional urinary metabolites of furan were also characterized as follows: R-2-acetylamino-6-(2,5-dihydro-2-oxo-1H-pyrrol-1-yl)-1-hexanoic acid, N-acetyl-S-[1-...
TL;DR: In isolation of an Enterococcus gallinarum strain capable of decolorizing and degrading DB38, the strain was found to reduce both toxicity and mutagenicity of DB38 metabolites.
TL;DR: Results indicated that these extracts could modulate the xenobiotic metabolising enzymes in the liver at the higher concentrations and exhibited strong antimutagenic activity against the mutagenicity of 2-aminoanthracene, a known mutagen, in the presence of S-9 metabolic activating enzymes.
TL;DR: Two studies provide additional evidence that Reb A is not genotoxic at the doses tested and further support the generally recognized as safe determination of Reb A.
TL;DR: Sulforaphane (1-isothiocyanato-(4 R )-(methylsulphinyl)butane), a major constituent of broccoli (Brassica oleracea, var. italica) and a structurally related natural aliphatic isothIocyanate, sulforaphen (4-ISOTHIOCyanate-(1 R )-1-(methyl sulphyl)-1-(E )-butene), found in radish (Raphanus sativus L., Cruciferae) were
TL;DR: In summary, despite an apparent lack of mutagenic and genotoxic activity, enniatin B can cause pronounced cytotoxicity in mammalian cells, detectable at low micromolar concentrations.
Abstract: The Fusarium metabolite enniatin B is now recognized as a frequent contaminant of grains used for human foods and animal feeds. Yet, so far very limited data are available on its toxicity and that of other emerging Fusarium mycotoxins (Jestoi M, 2008, Crit Rev Food Sci Nutr 48:21-49). Thus, the mutagenic/genotoxic potential of enniatin B was investigated in a battery of short-term tests, and its cytotoxicity compared with that of several other mycotoxins. No mutagenicity was detected in the Ames assay with four Salmonella typhimurium strains, and in the HPRT (hypoxanthine guanine phosphoribosyl transferase) assay with V79 cells, in either the presence or absence of an external metabolizing enzyme system (rat liver S9). For other types of genotoxicity, i.e., clastogenicity and chromosomal damage, studied in V79 cells by means of alkaline single-cell gel electrophoresis (Comet) assay and micronucleus assay, no significant genotoxic potential of enniatin B was revealed. However, the Fusarium metabolite exerts pronounced time- and concentration-dependent cytotoxic effects in V79 cells as determined by Alamar Blue reduction and by neutral red uptake assays. For instance, IC20 and IC50 values determined for enniatin B by neutral red assay for 48-h exposure are 1.5 μM and 4 μM. These values are higher than those of the more potent Fusarium toxin deoxynivalenol (IC20 0.7 μM, IC50 of 0.8 μM), but clearly lower than the IC values of several other mycotoxins tested in parallel. Their ranking of cytotoxicity in V79 cells was as follows: deoxynivalenol > enniatin B > patulin > ochratoxin A > zearalenone > citrinin. Moreover, enniatin B was found to induce nuclear fragmentation, a sign of apoptosis, already at low submicromolar concentrations. In summary, despite an apparent lack of mutagenic and genotoxic activity, enniatin B can cause pronounced cytotoxicity in mammalian cells, detectable at low micromolar concentrations.
TL;DR: 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.
TL;DR: A series of genotoxicity studies were performed to support the human safety of this azole antifungal drug, and support the view that climbazole does not present a genotoxic or carcinogenic risk to humans.
Abstract: Climbazole is an imidazole antifungal agent that can provide anti-dandruff benefits when incorporated into a shampoo matrix. A series of genotoxicity studies were performed to support the human safety of this azole antifungal drug. Climbazole was not mutagenic in the Salmonella typhimurium or Escherichia coli Ames assay and did not induce micronuclei in human lymphocytes. In the mouse lymphoma assay (MLA), climbazole was negative (non-mutagenic) with and without metabolic (S9) activation after a 4 h exposure; an increase in small colony mutants was observed without metabolic activation after a 24 h exposure at concentrations of 15 and 17.5 μg/mL. An in vivo mouse micronucleus test was negative up to a maximum tolerated dose (MTD) of 150 mg/kg climbazole administered orally. In the in vivo/in vitro unscheduled DNA synthesis assay, climbazole showed no evidence of DNA damage in the livers of rats at doses up to the MTD of 200 mg/kg orally. A toxicokinetic study was performed in mice with oral administration of [14C]-climbazole (150 mg/kg). Radioactivity (20.42 μg-equiv./g plasma) was detected 15 min after oral administration of [14C]-climbazole, and the peak concentration was 62.96 μg-equiv./g plasma at 8 h after dosing. The measured amounts of radioactivity in plasma, at all sample times from 15 min up to 24 h, exceeded the concentrations that induced increases in mutation frequency after 24 h exposure of mouse lymphoma cells in vitro (15 and 17.5 μg/mL). These observations lend support to the conclusion that climbazole does not present a genotoxic risk in vivo. Furthermore, these data are consistent with the published data for other azole antifungals that work by preventing the synthesis of ergosterol and, as a class, are generally non-genotoxic, except some isolated positive results of questionable significance. Collectively, these data are supportive of the view that climbazole does not present a genotoxic or carcinogenic risk to humans.
TL;DR: Genotoxicity of superparamagnetic iron-platinum nanoparticles capped with 2-aminoethanethiol (AET) was evaluated and clastogenicity of FePt NPs seemed to be false-positive in the in vitro chromosomal aberration test using Chinese hamster lung fibroblast cells.
Abstract: Genotoxicity of superparamagnetic iron-platinum (FePt) nanoparticles (NPs) capped with 2-aminoethanethiol (AET) was evaluated using the bacterial reverse mutation assay (Ames test) and in vitro chromosomal aberration test. Mutagenicity of AET-capped FePt NPs was found to be negative in the Ames test, while clastogenicity of FePt NPs seemed to be false-positive in the in vitro chromosomal aberration test using Chinese hamster lung fibroblast cells. However, further detailed in vitro genotoxicity tests, such as DNA adduct studies, are necessary to conclude that a positive aberration result is irrelevant.
TL;DR: Genotoxic risk of the aqueous extract of T. cordifolia in a battery of four different genotoxicity tests showed that TC treatment did not display clastogenicity and DNA damaging effect in bone marrow erythrocytes and peripheral blood lymphocytes respectively.
TL;DR: Different extracts were also found to be effective in protecting plasmid DNA against the strand breakage induced by hydroxyl radicals, except PE and aqueous extracts.
TL;DR: The wastewaters of Ghaziabad City (India), which is used for irrigation, were sampled and monitored for the presence of genotoxic agents from January 2005 to June 2007 and exhibited significant mutagenicity with TA98, TA97a, and TA100 strains with the probable role of contaminating pesticides in the wastewater.
Abstract: In most towns of India, wastewater coming from both industrial and domestic sources and without any treatment is used to irrigate the agricultural crops. This practice has been polluting the soil, and pollutants could possibly reach the food chain. For the above reasons, the wastewaters of Ghaziabad City (India), which is used for irrigation, were sampled (at two different sites) and monitored for the presence of genotoxic agents from January 2005 to June 2007. Gas chromatographic analysis showed the presence of certain OC (DDE, DDT, Dieldrin, Aldrin, and Endosulfan) and OP (Dimethoate, Malathion, Methlyparathion, and Chlorpyrifos) pesticides in both the sampling sites. Wastewater samples were concentrated using XAD resins (XAD-4 and XAD-8) and liquid–liquid extraction procedures, and the extracts were assayed for genotoxic potential by Ames Salmonella/microsome test, DNA repair defective mutants, and bacteriophage λ systems. The test samples exhibited significant mutagenicity with TA98, TA97a, and TA100 strains with the probable role of contaminating pesticides in the wastewater. However, XAD-concentrated samples were more mutagenic in both sites as compared to liquid–liquid-extracted samples. The damage in the DNA repair defective mutants in the presence of XAD-concentrated water samples were also found to be higher to that of liquid–liquid-extracted water samples at the dose level of 20 μL/mL culture. All the mutants invariably exhibited significant decline in their colony-forming units as compared to their isogenic wild-type counterparts. The survival was decreased by 81.7 and 75.5% in polA− strain in site I, and 76.0 and 73.5% in site II in polA− under the same experimental conditions after 6 h of treatment with XAD-concentrated and liquid–liquid-extracted samples, respectively. A significant decrease in the survival of bacteriophage λ was also observed when treated with the test samples. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2009.
TL;DR: The biochemical basis for S9-dependent mutagenic response of the 5-HT(2C) receptor agonist and diazinylpiperazine derivative 1 in the Salmonella Ames assay involves P450-mediated bioactivation to DNA-reactive quinone-methide, aldehyde and nitrone intermediates.
TL;DR: Two short-term assays were carried out to evaluate the genotoxicity of five nitriles and the comet assay seems to be more sensitive than the modified Ames test.
TL;DR: The results of the alkaline comet assay indicate significant DNA damaging potential of wastewater for human leukocytes, and phosphoric gypsum transport water in its present composition and acidity is highly toxic and acts as prooxidant.
Abstract: In this study we investigated cytotoxic, mutagenic and genotoxic effects of different concentrations of wastewater from the phosphoric gypsum depot near the factory for fertilizing agents 'INA Petrokemija' (Kutina, Croatia) The Ames test was performed on Salmonella typhimurium TA98 and TA100 strains, in the presence of S9 mix, glutathione and buffer, respectively Cytotoxicity was studied on human laryngeal carcinoma cells (HEp2) and human cervical cells (HeLa) The level of lipid peroxidation in these two cell lines was evaluated in parallel To establish the levels of primary DNA damage, the alkaline comet assay was performed on treated human peripheral blood leukocytes No mutagenic effects of phosphoric gypsum on Salmonella typhimurium strains in the presence of S9 mix, GSH or PBS were observed However, strong cytotoxic effect was observed on both human cell lines when they were treated with different concentrations of wastewater Lipid peroxidation was induced and increased by prolonged time of incubation, highlighting that the damage was not repaired, but increased with the time of incubation The results of the alkaline comet assay indicate significant DNA damaging potential of wastewater for human leukocytes Since phosphoric gypsum transport water in its present composition and acidity is highly toxic and acts as prooxidant, causing free radicals formation and DNA damage, urgent neutralization/purification of the wastewater to a level acceptable for disposal into the environment is mandatory
TL;DR: In vivo anti-cancer effect of Adenophora triphylla extract was tested using Balb/c mice transplanted sarcoma-180 cells and the extract and its fractions showed only 3∼36% cytotoxicity for a normal human kidney cell line (293).
Abstract: The Nutraceutical Bio Brain Korea 21 Project Group, Kangwon National University, Gangwon 200-701, KoreaAbstractThis study was carried out to investigate the mutagenic, antimutagenic, cytotoxicity and antitumor effects of Adenophora triphylla (AT). AT was extracted with 70% ethanol and then further fractionated to hexane, chloroform, ethyl acetate, butanol and water. Antimutagenic, cytotoxicity and antitumor effects of AT extracts were measured by using Ames test, SRB method, and the tumor growth inhibition test. AT extracts did not show any mutagenicity in the Ames test; however, 70% ethanol extracts and its fractions had strong antimutagenic effects against mutation induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and 4-nitroquinoline-1-oxide (4NQO). The ethyl acetate fraction of AT (200 μg/plate) showed approximately 66.5% inhibitory effect on the mutagenesis induced by 4NQO against TA98 strain, whereas 83.3% and 75.1% inhibitions were observed on the mutagenesis induced by MNNG and 4NQO against TA100 strain. In anticancer effects, the cytotoxicity of AT extract and its fractions against cancer cell lines including human cervical adenocarcinoma (HeLa), human hepatocellular carcinoma (Hep3B), human breast adenocarcinoma (MCF-7), human gastric carcinoma (AGS), human lung carcinoma (A549) and transformed primary human embryo kidney (293) were investigated. The treatment of 1 mg/mL AT ethyl acetate faction had the highest cytotoxicity of 79.9%, 74.9%, 66.0%, 71.0% and 74.3% against HeLa, Hep3B, MCF-7, AGS and A549 cells, respectively. In contrast, the extract and its fractions showed only 3∼36% cytotoxicity for a normal human kidney cell line (293). In vivo anti-cancer effect of Adenophora triphylla extract was tested using Balb/c mice transplanted sarcoma-180 cells. Adenophora triphylla ethyl acetate fraction showed the highest inhibition rate of 37.2% at the 50 mg/kg concentration.Key words: Adenophora triphylla, Ames test, antimutagenicity, antitumor, cytotoxicity
TL;DR: Investigation of the effects of crude extracts of whole cacao products on the mutagenicity of benzo[a]pyrene and tert‐butyl hydroperoxide in Salmonella strains suggests inhibition of CYP1A activity by cacao Products may prevent DNA damage by reducing metabolic activation of carcinogens.
Abstract: Polyphenols have been shown to have potent antioxidant activity, and therefore, food containing polyphenols is expected to contribute to the prevention of cancer. However, food contains not only polyphenols but also various other constituents. We used the Ames test to investigate the effects of crude extracts of whole cacao products, which are known to be rich in polyphenols, on the mutagenicity of benzo[a]pyrene (B[a]P) in Salmonella typhimurium strain TA 98 and tert-butyl hydroperoxide (t-BuOOH) in S. typhimurium strain TA 102. B[a]P induces mutagenicity by metabolic activation and t-BuOOH induces it by generation of free radicals. While white chocolate did not modulate the numbers of revertant colonies produced by B[a]P treatment, milk chocolate and cacao powder extracts did. On the other hand, surprisingly, none of the cacao products tested affected the number of revertant colonies when t-BuOOH was used as the mutagen. At maximum concentration (13.25 mg cacao powder/ml), the crude cacao powder extract reduced ethoxyresorufin O-deethylase activity to 17.4% of the control, suggesting that whole cacao products inhibit cytochrome P450 (CYP) 1A activity. In conclusion, inhibition of CYP1A activity by cacao products may prevent DNA damage by reducing metabolic activation of carcinogens.
TL;DR: The tests confirmed the non-mutagenic but reasonably antimutagenic activities of the two plant extracts, supporting their current use as safe dietary supplements and cosmetics.
Abstract: Pueraria mirifica is a Thai phytoestrogen-rich herb traditionally used for the treatment of menopausal symptoms. Pueraria lobata is also a phytoestrogen-rich herb traditionally used in Japan, Korea and China for the treatment of hypertension and alcoholism. We evaluated the mutagenic and antimutagenic activity of the two plant extracts using the Ames test preincubation method plus or minus the rat liver mixture S9 for metabolic activation using Salmonella typhimurium strains TA98 and TA100 as indicator strains. The cytotoxicity of the two extracts to the two S. typhimurium indicators was evaluated before the mutagenic and antimutagenic tests. Both extracts at a final concentration of 2.5, 5, 10, or 20 mg/plate exhibited only mild cytotoxic effects. The plant extracts at the concentrations of 2.5, 5 and 10 mg/plate in the presence and absence of the S9 mixture were negative in the mutagenic Ames test. In contrast, both extracts were positive in the antimutagenic Ames test towards either one or both of the tested mutagens 2-(2-furyl)-3-(5-nitro-2-furyl)-acrylamide and benzo(a)pyrene. The absence of mutagenic and the presence of anti-mutagenic activities of the two plant extracts were confirmed in rec-assays and further supported by a micronucleus test where both plant extracts at doses up to 300 mg/kg body weight (equivalent to 16 g/kg body weight plant tuberous powder) failed to exhibit significant micronucleus formation in rats. The tests confirmed the non-mutagenic but reasonably antimutagenic activities of the two plant extracts, supporting their current use as safe dietary supplements and cosmetics.
TL;DR: In this paper, the authors examined the mutagenic and antimutagenic activities of the DMSO extracts from the oat, buckwheat and wheat bran, which are good sources of polyphenols with antioxidant and anticarcinogenic properties.
TL;DR: Controlling of bromide and DOC concentrations is an effective method of reducing potential by-product formation and eliminating mutagenicity problems associated with groundwater ozonation.
Abstract: Brominated organic and inorganic by-products are generated during ozonation of groundwater containing high bromide concentrations. This study measured concentrations of bromate, bromoform, bromoacetic acids, bromoacetonitriles, bromoacetone, 2,4-dibromophenol and aldehyde generated by ozonation. The potential mutagenicity of ozonated waters was assessed using the Ames and Microtox tests. Test results for the 18 ozonated groundwater samples demonstrate that bromate formation is associated with high pH, bromide and alkalinity content, low levels of dissolved organic carbon (DOC) and ammonia, and low alkalinity. Brominated organic by-products were correlated with high bromide ion and natural organic matter content, and low ammonia concentrations. The Ames test results demonstrate that all extracts from ozonated water have mutagenic activity; however, the 18 raw groundwater samples had no mutagenicity. The Microtox test results also show that the ozonated water samples were highly toxic. Generally, both bromide and DOC content promoted the formation of ozonation by-products and mutagenicity. Controlling of bromide and DOC concentrations is an effective method of reducing potential by-product formation and eliminating mutagenicity problems associated with groundwater ozonation.