Mutagenicity assay in Salmonella for thirteen 2-substituted-1 H-phenanthro (9,10-d) imidazoles

Some 2-substituted-1 H-phenanthro [9,10-d] imidazole compounds synthesized as a predrugs were tested in mutagenicity assays in Salmonella strains TA97, TA98, and TA100 using a plate incorporation assay both with and without S9 mix. The 10 substances were mutagenic in TA97 and five of them were mutagenic only with metabolic activation, whereas one of them did not require the addition of S9. The eight substances were mutagenic in TA98 only with S9. For TA100, seven substances showed positive results both with and without S9, however another four required S9, whereas only one of them did not required metabolic activation. In summary, all of 13 substances derived from phenanthro [9,10-d] imidazole were found to be mutagenic for at least one or two of the three strains and their mutagenicity are discussed.     

Genotoxicity assessment through the Ames test of medicinal plants commonly used in Brazil

Ten medicinal herbs commonly used as popular medicine in Brazil—Bauhinia forficata L., Bauhinia variegata L., Cymbopogon citratus D.C. Stapf, Echinodorus macrophyllum (Kunth) Micheli, Hidrocotyle asiatica L, Matricaria chamomila L., Pfaffia iresinoides (Kunth) Sprengel, Plaffia paniculata (Martius) Kuntze, Phyllanthus tenellus Roxb, and Solidago microglossa D.C.—were tested for mutagenicity by the Ames test using Salmonella typhimurium TA 97a, TA 98, TA 100, and TA 104 strains, with and without metabolic activation. The genotoxicity assessment of these medicinal plants was performed in aqueous extracts 1:5. Seventy percent of these herbs presented mutagenic effects with at least one of the Ames strains used in this study. Bauhinia variegata L., E. macrophyllum K., and M. chamomilla L. showed no mutagenic activity. The mutagenic effects were detected mainly with the strains TA 98 related to frameshift mutations. The higher mutagenicity ratio was obtained with S. microglossa D.C. (known as arnica-do-Brazil) when TA 98 strain was used with metabolic activation (MR = 6.55) and with TA 97a strain with and without the addition of S9. Medicinal plants are now used by all the segments of the population, more intensively in the last years. These results indicate the need to establish rules to assess the safety of the use of medicinal herbs. © 1994 by John Wiley & Sons, Inc..     

Mutagenic activity of the feces of rats following oral administration of tartrazine

After oral administration of the azo dye tartrazine, bile and feces of treated rats were investigated for mutagenicity using the Ames test withSalmonella typhimurium strains TA 98 and TA 100 with and without metabolic activation. In the presence of S 9-mix fecal extracts developed a weak but reproducible dose-related response in strain TA 100. In bile no metabolites exerting mutagenic activity were found.     

Mutagenicity of Mouriri pusa Gardner and Mouriri elliptica Martius

Mouriri pusa Gardner and Mouriri elliptica Martius are fruit-bearing plants of the Melastomataceae family, popularly known in Brazil as puçá-preto or jaboticaba-do-cerrado, and they are used in folk medicine for the treatment of gastric ulcers. In this study, we employ the Ames test to assess the mutagenicity of compounds obtained from the leaves of these species. The methanol extract of the M. pusa was mutagenic to the Salmonella typhimurium strains TA98, TA97a and TA100, with or without metabolic activation. The methanol extract of M. elliptica induced mutagenic activity in TA98 when metabolized with S9 fraction and TA97a with and without S9, but with lower mutagenicity index (MI) and potencies values than those for M. pusa. Enriched fractions of flavonoids and tannins of M. pusa were also evaluated and they demonstrated positive mutagenicity. The highest values of MI and potency were obtained with the flavonoid fraction, which contains large amounts of quercetin, quercetin glycosides and myricetin. These compounds are probably related to the mutagenicity observed in the Ames test. The dichloromethane extract was not mutagenic in any of the test conditions employed.     

Mutagenicity of environmental samples from an industrialized area of the Rio de la Plata Estuary using the salmonella/microsomal assay

Mutagenic characterization was applied to study the environmental compartments of a heavily industrialized area. Polycyclic aromatic hydrocarbons have been previously detected in the environmental samples of different compartments. Salmonella typhimurium strains TA98 and TA100 were used for screening the mutagenic activity of airborne particulate matter, sediments, surface waters, and industrial wastewaters. The tests were performed with and without S9 metabolic activation. Results of the tests showed mutagenicity in those assays with metabolic activation. Sampling points with higher activity reached a value of 25,258/44,106 His+ rev/g in airborne particulate matter samples and 8,549,500/5466 His+ rev/L water samples, for strains TA98 and TA100, respectively, and 15,128 His+ rev/g in sediment samples for TA98. Apparently, a strong mutagenicity in water and sediment samples is associated with sectors near point sources of pollution. © 1996 by John Wiley & Sons, Inc.     

Monitoring sãto paulo state rivers in brazil for mutagenic activity using the ames test

Organic extracts of raw water from 11 water courses of São Paulo State, Brazil, were collected during one year bimonthly and tested for mutagenicity using the Ames test, with strains TA98 and TA100 of Salmonella typhimurium with and without metabolic activation. The samples were extracted with XAD₂ resin and eluted with methanol and methylene chloride. From the 75 samples analyzed, 14 showed positive responses and 8 were considered marginal, making up 29% of mutagenic samples. The percentage of mutagenic samples in October (spring) was 9%, increasing to 64% in February (summer), and decreased to 9% again in August (winter). Paraiba do Sul river showed the higher percentage of mutagenic samples (67%) and Capivari river the highest mutagenic sample (1787 and 3265 revertants per liter for TA98 without and with S9, respectively). The amplitude of the mutagenic response was 39–3265 revertants per liter for TA98 and 83–467 for TA100. The mutagenic samples showed direct and indirect mutagens, and TA98 detected the majority of responses, indicating prevalence of frameshift mutagens in these samples. © 1993 John Wiley & Sons, Inc.     

Mutagenicity and toxicity studies of p-phenylenediamine and its derivatives

The mutagenicity of p-phenylenediamine and its derivatives was tested using Ames Salmonella strains TA98 and TA100. p-Phenylenediamine was weakly mutagenic to TA98 with metabolic activation. 2-Nitro-p-phenylenediamine was directly mutagenic to both strains, while 2-methyl-p-phenylenediamine required S9 mix. All the test compounds induced a dose-related increase in chromosomal aberrations m Chinese hamster ovary (CHO) cells in the absence of the S9 mix. The mutagenicity and toxicity of these compounds did not correlate with their oxidation potentials, or any other tested physicochemical properties including the energy difference between the lowest unoccupied and the highest occupied molecular orbital, ionization potential, and dipole moment.     

Screening of tabacco smoke constituents for mutagenicity using the Ames' test

To clarify the mutagenic activity of individual smoke components, 239 compounds, representative of the gaseous and semivolatile phases of tobacco smoke, were assayed for mutagenicity towards 4 histidine-requiring mutants of Salmonella typhimurium (TA 98, TA 100, TA 1535 and TA 1537). All compounds were tested qualitatively both with and without metabolic activation using a liver fraction (S-9) from Aroclor 1254 or methylcholanthrene induced rats. Without S-9, only 2,3-dimethylindole and 2,3,5-trimethylindole showed mutagenic activity that was not enhanced by hte metabolic activation system. 2,6-Diaminotoluene and coronene, which like the above compounds are not documented carcinogens were found to be mutagenic for strain TA 98 with S-9. Mutagenic activity was also observed for the previously known mutagens benz[a]pyrene, chrysene, benz[a]-anthracene, perylene and β-naphthylamine, on exposure to strains TA 98 and/or TA 100 with S-9.     

In vitro mutagenicity of rubber chemicals and their nitrosation products

14 chemicals employed in rubber manufacture were assayed in the Salmonella reversion test with the strains TA98 and TA100. Mixed diaryl-p-phenylenediamines were weakly mutagenic in TA98 after metabolic activation; poly-p-dinitrosobenzene was active in TA98 without as well as with S9. After in vitro reaction with nitrite at low pH, mixed diaryl-p-phenylenediamines became directly mutagenic in both strains, whereas poly-p-dinitrosobenzene retained its activity unchanged. Furthermore, 4 of the remaining chemicals acquired mutagenic characteristics: in the presence of S9, N,N'-dimethylpentyl-p-phenylenediamine reverted TA98 and hexamethylenetetramine reverted both TA98 and TA100; N-isopropyl-N'-phenyl-p-phenylenediamine was mutagenic in TA98 with and without S9; N-nitrosodiphenylamine was active in both strains without S9 and weakly mutagenic in TA98 after metabolic conversion.     

Mutagenicity and cytotoxicity of N-methyl-2-pyrrolidinone and 4-(methylamino)butanoic acid in the Salmonella/microsome assay

The industrial solvent N-methyl-2-pyrrolidinone (NMP) and its hydrolysis product, 4-(methylamino)butanoic acid (N-MeGABA), were examined for mutagenicity and cytotoxicity in the Ames Salmonella/microsome assay. In order to detect a broad range of possible mutagenic endpoints, the following strains were used in the assay: base-pair substitution strains TA100, TA102 and TA104; frameshift strains TA97 and TA98; and repair proficient strains TA2638, UTH8413 and UTH8414. In the standard plate incorporation assay, six log-linear doses of each compound were tested; doses ranged from 0.01 to 1000 mumol/plate for NMP, and 0.01 to 316 mumol/plate for N-MeGABA. Neither compound was detectably mutagenic when tested in the presence and absence of metabolic activation by Aroclor-induced rat liver S9. NMP did show significant responses with strains TA102 and TA104 that were less than two-fold over background, but no clear dose-response relationships were evident. A preincubation modification of the assay was also performed, using strains TA98 and TA104. Mutagenic activity was not observed for NMP, while N-MeGABA showed significant responses with TA104 but dose-related mutagenicity was not established. Preincubation testing revealed both NMP and N-MeGABA to be cytotoxic to the test population of Salmonella at the highest treatment doses.     

Mutagen formation in the reaction of maillard browning products, 2-acetylpyrrole and its analogues, with nitrite

Three 2-substituted pyrroles (2-acetylpyrrole, pyrrole-2-carboxaldehyde and pyrrole-2-carboxylic acid), which are products of the Maillard browning reaction, were reacted with nitrite in buffer solution (pH 3) at 50°C for 24 hr. The reaction mixtures were extracted with methylene chloride and the extracts were tested for mutagenicity using Salmonella typhimurium strains TA97, TA98, TA100, TA102 and TA104, with and without S-9 metabolic activation. The methylene chloride extract of the 2-acetylpyrrole-nitrite reaction mixture showed strong mutagenicity to all the tester strains, both in the presence and absence of S-9 mix. The reaction product of pyrrole-2-carboxaldehyde with nitrite only gave a weak mutagenic response with strain TA100, while the pyrrole-2-carboxylic acid-nitrite reaction product did not produce a mutagenic response in any of the tester strains. Two mutagenically active fractions, separated by thin-layer chromatography, were found in the reaction of 2-acetylpyrrole with nitrite. The formation of mutagenic products in the latter reaction was found to vary with reaction pH, time and temperature, with nitrite level and with 2-acetylpyrrole concentration.     

Detection of genotoxicity and mutagenicity of chlorthiophos using micronucleus,chromosome aberration,sister chromatid exchange,and Ames tests

Potential mutagenic and genotoxic effects of Chlorthiophos, an organophosphate pesticide, were evaluated using four standard assays. Five different concentrations of the pesticide were tested by an Ames test using Salmonella typhimurium strains TA97, TA98, TA100, and TA102, with and without S9 metabolic activation. No concentrations of Chlorthiophos showed mutagenic activity on the TA97, TA100, and TA102 strains, with and without S9 fraction, but were all mutagenic to the TA98 strain without S9. Sister chromatid exchange (SCE), chromosome aberration (CA), and micronucleus (MN) tests were used to investigate the genotoxic effects of Chlorthiophos in human peripheral lymphocytes treated with 25, 50, 100, and 200 µg/mL concentrations of Chlorthiophos for 24 and 48 h. The nuclear division index (NDI), replication index (RI), and mitotic index (MI) were also calculated to determine the cytotoxicity of Chlorthiophos. No increase in SCE frequency was seen for any treatment period or concentration, but Chlorthiophos at 200 µg/mL increased the frequency of CAs. Increases in MN formation were only observed at Chlorthiophos concentrations of 200 µg/mL following 24 and 48 h treatments. Chlorthiophos treatment reduced the MI and NDI significantly, but had no effect on the RI. © 2014 Wiley Periodicals, Inc. Environ Toxicol 30: 937–945, 2015.     

Antioxidant,mutagenic and antimutagenic activities of an aqueous extract of Limoniastrum guyonianum gall

Abstract

An aqueous extract of Limoniastrum guyonianum gall (G extract) was tested on Salmonella typhimurium to assess its mutagenic and antimutagenic effects. This extract showed no mutagenicity when tested with S. typhimurium strain TA104 either with or without exogenous metabolic activation mixture (S9), whereas our findings revealed that the aqueous gall extract induced a mutagenic effect in S. typhimurium TA1538 when tested in the presence, as well as in the absence, of S9 activation mixture at the concentration of 500?µg/mL. Thus, the same concentration produced a mutagenic effect, when incubated with S. typhimurium TA100 in the presence of metabolic activation mixture. In contrast, our results showed a weak antimutagenic potential of the same extract against sodium azide in the presence of S. typhimurium TA100 and S. typhimurium TA1538 without metabolic activation (S9), whereas, in the presence of S. typhimurium TA104, we obtained a significant inhibition percentage (76.39%) toward 3.25?µg/plate of methylmethanesulfonate. Antimutagenicity against aflatoxin B1, 4-nitro-o-phenylene-diamine and 2-aminoanthracène was significant, with an inhibition percentage of, respectively, 70.63, 99.3 and 63.37% in the presence of, respectively, S. typhimurium TA100, S. typhimurium TA1538 and S. typhimurium TA104 strains at a concentration of 250?µg/plate after metabolic activation (S9). Antioxidant capacity of the tested extract was evaluated using the enzymatic (xanthine/xanthine oxidase assay) and the nonenzymatic (2,2-diphenyl-1-picrylhydrazyl) system. G extract exhibited high antioxidant activity.     

茜素型蒽醌基因突变风险评价

目的 使用毒性预测软件及细菌回复突变（Ames）试验评价茜素型蒽醌的基因突变风险。方法 通过毒性软件Toxtree、Derek Nexus和Sarah Nexus对茜素型蒽醌：茜草素、异茜草素、甲基异茜草素、甲基异茜草素-1-甲醚、茜素-1-甲醚、羟基茜草素、光泽汀进行致突变风险预测;每个受试物设置5个给药浓度,分别在有或无S9代谢活化条件下,使用5种鼠伤寒沙门氏菌TA97、TA100、TA102、TA1535和TA1537开展基于6孔板培养的Ames试验,判断该类化合物苯环上不同取代基对致突变性的影响。结果 软件基于蒽醌环的存在预测该类化合物均具有致突变风险。在非S9代谢活化下,异茜草素和羟基茜草素可导致TA1537回复突变菌落数增加;光泽汀可诱导TA97、TA100和TA1537回复突变菌落数增加。在S9代谢活化下,异茜草素可导致TA97、TA100和TA1537回复突变菌落数增加;羟基茜草素可导致TA1537回复突变菌落数增加;光泽汀可导致TA97、TA100和TA1537回复突变菌落数增加;甲基异茜草素可导致TA97、TA100、TA102和TA1537回复突变菌落数大幅增加;甲基异茜草素-1-甲醚可导致TA100回复突变菌落数增加。结论 茜素型蒽醌受试物在有或无S9代谢条件下表现出不同程度、不同菌株的回复突变,开展相关研究评价其毒性风险对该类化合物合理监管具有重要价值。     

Evaluation of the mutagenic activity of phenolics from the bark of Yucca schidigera Roezl

The mutagenic activity of yuccaols A, B, and C, trans-resveratrol and trans - 3.3',5.5'-tetrahydroxy -4'-methoxystilbene was tested by the Ames method with Salmonella typhimurium strains TA97, TA98, TA100, TA102 in the absence and presence of metabolic activation (S9 fraction). These phenolic compounds have been isolated and identified from the hark of Yucca schidigera. All of them were found to be non-toxic and non-mutagenic for testing doses in any of the S. typhimurium strains.     

Mutagenicity evaluation of riot control agent o-chlorobenzylidene malononitrile (CS) in the Ames Salmonella/microsome test.

o-Chlorobenzylidene malononitrile (CS), a riot control agent, was evaluated for its possible mutagenic activity in the Ames Salmonella/mammalian microsome mutagenicity test. Five histidine-deficient (His-) mutant tester strains of Salmonella typhimurium--TA97a, TA98, TA100, TA102 and TA104--were used. The liquid preincubation procedure was used with metabolic activation (presence of S9 mixture) and without metabolic activation (absence of S9 mixture). For the experiments with metabolic activation, three different concentrations of S9 fraction (supernatant of Aroclor 1254-induced rat liver homogenate at 9000 g)--5%, 15% and 30% in S9 mixture--were used. Along with mutagenic activity, CS was also evaluated for cytotoxic activity in all the five tester strains of Salmonella typhimurium, both in the presence and absence of S9 mixture. The mutagenic and cytotoxic activities of CS were assessed by counting the His+ revertant colonies and by counting the microcolonies (His-, auxotrophs in the background lawn), respectively, and the respective mean values were compared with the relative negative (solvent) control. A dose range of 12.5-800 micrograms plate-1 for CS did not induce a mutagenic response either in the presence or absence of S9 mix. No change in the negative mutagenic response of CS has been observed even in the presence of an elevated level of S9 fraction in the S9 mix. A dose of 200 micrograms plate-1 for CS was found to be cytotoxic by decreasing the surviving cells as well as His+ revertant colonies; however, the effect was reduced in the presence of an elevated level of S9 fraction in the S9 mix.     

Mutagenic activity promoted by amentoflavone and methanolic extract of Byrsonima crassa Niedenzu

Byrsonima crassa is a plant pertaining to the Brazilian central savannah-like belt of vegetation and popularly used for the treatment of gastric dysfunctions and diarrhoea. The methanol extract contains catechin, tannins, terpenes and flavonoids; both mutagenic potential and antioxidant properties have been ascribed to flavonoids. The mutagenicity of some flavonoids is believed to be associated with the formation of reactive oxygen species and seems to depend on the number and position of hydroxyl groups. In the present study the mutagenic activity of the methanol, chloroform and 80% aqueous methanol extracts, as well as acetate and aqueous sub-fractions, of this medicinal plant were evaluated by Salmonella typhimurium assay, using strains TA100, TA98, TA102 and TA97a, and in mouse reticulocytes. The results showed mutagenic activity of the methanolic extract in the TA98 strain without S9, but no mutagenicity to mouse cells in any of the extracts. The acetate fraction showed strong signs of mutagenicity without S9, suggesting that in this enriched fraction were concentrated the compounds that induced mutagenic activity. The aqueous fraction showed no mutagenic activity. The TLC and HSCCC analyses of the acetate fraction with some standard compounds permitted the isolation of the quercetin-3-O-beta-D-galactopyranoside, quercetin-3-O-alpha-L-arabinopyranoside, amentoflavone, methyl gallate and (+)-catechin, of which only the amentoflavone exhibited positive mutagenicity to TA98 (+S9, -S9).     

Mutagenic activity of the condensates from thermal decomposition of different polyamides]

The mutagenic activity of the condensates from oxydative pyrolysis of various polyamides at 500, 800 and 1,000 degrees C has been searched for by AMES preincubation test in strains TA 98 and TA 100 with or without metabolic activation by an Aroclor 1254 induced rat liver microsomal S9mix fraction. All condensates are mutagenic in the presence of this fraction and most of them are far less or not mutagenic in the absence of S9mix. Strain TA 98 is more sensitive than strain TA 100 for detecting the mutagenic activity of these condensates. So, they mainly contain indirect mutagenic substances responsible for frameshift mutation. In all cases, mutagenic activity is maximum at 800 degrees C. This observation should draw the attention upon the genotoxic (carcinogenic) long term risk induced by thermal decomposition of plastics and then upon the necessary protection of firemen and others in charge of domestic or hospital solid waste incineration.     

Ames mutagenicity tests of products from a heated potato-starch system

A charred sample was prepared from potato starch heated with ammonium carbonate at 600°C in a flask under a nitrogen stream. The water produced was collected and extracted with methylene chloride. The basic fraction obtained from the extract exhibited strong mutagenicity in Ames assays using Salmonella typhimurium strains TA98 or TA100 with metabolic activation (rat-liver S-9 mix). The basic fraction was further fractionated by silica gel column chromatography and subsequently by Scphadex column chromatography. Some of the resulting fractions exhibited strong mutagenic activities in S. typhimurium strain TA98 with S-9 mix.     

Antimutagenic and anticlastogenic effects of Turkish Black Tea on TA98 and TA100 strains of Salmonella typhimurium (in vitro) and mice (in vivo)

Context: Black tea has been reported to have significant antimutagenic and anticarcinogenic properties associated with its polyphenols theaflavins (TF) and thearubigins (TR). Similarly, Turkish black tea (TBT) also contains a considerable amount of TF and TR.

Objective: This study investigated the mutagenic, antimutagenic and anticlastogenic properties of TBT.

Materials and methods: The mutagenic and antimutagenic effects of TBT (10 to 40000?μg/plate) were investigated in vitro on Salmonella strains TA98 and TA100 with and without S9 fraction. Anticlastogenic effect was studied at concentrations of 300–1200?mg/kg TBT extract by chromosomal aberrations (CA) assay from bone marrow of mice.

Results: The results of this study did not reveal any mutagenic properties of TBT. On the contrary, TBT extract exhibited antimutagenic activity at >1000?μg/plate concentrations in TA98 strain with and without S9 activation (40% inhibition with S9 and 27% without S9). In TA100 strain, the antimutagenic activity was observed at?>20,000?μg/plate TBT extracts without S9 activation (28% inhibition) and at >1000?μg/plate with S9 activation (59% inhibition). A significant decrease in the percentage of aberrant cells (12.33%?±?1.27) was observed in dimethylbenz(a)anthracene (DMBA) plus highest concentration (1200?mg/kg) of TBT extract-treated group when compared to only DMBA-treated group (17.00%?±?2.28).

Discussion and conclusion: Results indicated that TBT can be considered as genotoxically safe, because it did not exert any mutagenic and clastogenic effects. As a result, TBT exhibited antimutagenic effects more apparently after metabolic activation in bacterial test system and had an anticlastogenic effect in mice.