Genotoxicity assessment of new synthesized acridine derivative--3,6-diamino-10-methyl-9,10-dihydroacridine.

A new synthesized acridine derivative, 3,6-diamino-10-methyl-9, 10-dihydroacridine (AcrH), was tested for in vitro reverse mutations with Salmonella TA strains, chromosome aberrations and sister chromatid exchanges (SCE) in human lymphocytes, and for in vivo chromosome aberrations in bone marrow of mice. Using the classic plate incorporation method, mutagenicity of AcrH in bacterial cells (TA97a, TA98, TA100 and TA102) was observed in the experiments performed with, and without, rat liver S9 metabolic activation. The reverse mutation assay showed no difference in mutagenic activity between AcrH and acriflavine (Acr(+)) in the test with TA97. The results of in vitro chromosome aberrations assay revealed potential clastogenicity. The test using macroculture of human lymphocytes induced mainly chromatid gaps. The experiments with human lymphocytes revealed SCE-inducing effect of AcrH and Acr(+). In an in vivo study, AcrH given intraperitoneally to Balb/c mice did not cause any significant increase in the percentage of cells with aberrations compared to the negative control.

Mutagenic activity of 3,6-diamino-10-methyl-9,10-dihydroacridine in Salmonella typhimurium cells.

Mutagenic evaluation of 3,6-diamino-10-methyl-9,10-dihydroacridine (AcrH), a new synthesized acridine derivative was undertaken using short-term in vitro test. The mutagenic potential of AcrH was evident from the reverse mutation induced in the presence and absence of S9-mix of Salmonella typhimurium TA97a, TA98, TA100 and TA102 cells. The levels of the mutagenic activity of AcrH in TA97a are comparable with that of acriflavine.

Genotoxicity evaluation of tetramethylbenzenes.

The three tetramethyl isomers of benzene (prenitene, 1,2,3,4-; izodurene, 1,2,3,5-; and durene, 1,2,4,5-tetramethylben- zene) were studied using in vitro mutagenicity and in vivo genotoxicity tests. Potency of mutate induction by these solvents was evaluated in Salmonella typhimurium cells with, and without S9-mix made from Aroclor 1254-induced rat liver S9. The potency of induction of micronuclei (MN) and sister chromatid exchanges (SCEs) by solvents was evaluated in bone marrow of mice. Izodurene displayed mutagenic potency in strains TA97a, TA98 and TA100 only in the absence of the S9-mix. In MN tests, all three tetramethylbenzenes demonstrated no clastogenic activity on the bone marrow cells. All the tested solvents were active as genotoxic compounds in the SCE tests, demonstrating a dose-response relationships.

Genotoxicity of Farbasol and its component: 4-ethyltoluene.

A combination of assays for gene mutations in Salmonella typhimurium TA97a, TA98, TA100 and TA102 strains with and without rat liver activation, and for micronucleus and sister chromatid exchange (SCE) in bone marrow cells of Imp:Balb/c mice was used to provide data on the mutagenic and genotoxic properties of the mixture of aromatic solvents, known under the trade name of Farbasol. In addition, 4-ethyltoluene (the main ethylmethylbenzenic component of Farbasol) was also tested for muta- and genotoxicity. The results revealed that neither Farbasol nor 4-ethyltoluene induced an increased reverse mutation in bacterial cells or the formation of micronucleated polychromatic erythrocytes in bone marrow. However, those compounds were found to be active as sister chromatid exchange (SCE) agents.

Genotoxicity evaluation of trimethylbenzenes.

The three trimethyl isomers of benzene (hemimellitene, 1,2,3-TMB; pseudocumene, 1,2,4-TMB and mesitylene, 1,3,5-TMB) were investigated for different genotoxicity endpoints: in vitro, in the Ames test with Salmonella typhimurium TA97a, TA98, TA100 and TA102 strains in the presence and absence of rat liver S9 metabolic activation; in vivo, in the micronucleus and sister chromatid exchange (SCE) tests with bone marrow cells of Imp:Balb/c mice. Only the isomer of benzene with the methyl-group at position 1, 2, 3 was found to have mutagenic effect on S. typhimurium cells. Increase in bacterial reversions was observed in four conventional strains used in this study, but most clearly in TA97a. The mutagenic responses of 1,2,3-TMB with the SalmonellaL tester strains were observed in the experiments performed in the absence of enzymatic activation. None of the compounds had an influence on the frequency of micronucleated polychromatic erythrocytes in bone marrow cells of mice. However, all the three compounds were observed to have a cytogenetic potential of increasing the SCE level in these cells. Significant responses in SCE induction, compared with the level of those changes in corresponding solvent-administered controls, were obtained at three test doses of 1,2,3-TMB (730, 1470, 2200 mg/kg) and 1,2,4-TMB (900, 1800, 2700 mg/kg) and at two doses of 1,3,5-TMB (1800, 2700 mg/kg). These data provided a limited evidence for the genotoxic activity of 1,2,3-TMB and inadequate evidence for genotoxic activity of 1,2,4-TMB and 1,3,5-TMB.

Mutagenic and genotoxic activity detected by the Ames, micronucleus and SCE tests under the influence of samples of dyes manufactured in Poland.

In this study, we evaluated the mutagenic and genotoxic potential of commercial samples of chemicals manufactured by Polish dyestuff industry for their ability to mutate Salmonella typhimurium strains (TA97a, TA98, TA100 and TA102), and to induce formation of micronuclei (MN) and sister chromatid exchanges (SCE) in mice bone marrow cells. This study involved five dyes selected from a list of colorants, considered to be representative of those which were most extensively used in the trade. According to criteria listed by IARC (1984), the results obtained in this work and earlier tests of Basic Blue 26, 44045 and Direct Red 83, 29225 provided no evidence of genetic activity (all 3 tests were negative); for Acid Violet 49, 42640 and Disperse Blue 37, the evidence of genetic activity was inadequate (1 test was positive) and the tests for Acid Black 194 provided limited evidence of genetic activity (2 positive tests).

Comparison of the mutagenicity of chemical agents released during coke production.

Benzene- and acetone-extracted samples of airborne particulate matter collected in two coke plants were analysed for their content of genotoxic agents (coal tar pitch volatiles (CTPVs), polycyclic aromatic hydrocarbons (PAHs): benzo/a/pyrene, pyrene, dibenzo/a,h/anthracene, anthracene and fluoranthene) following the identification and quantification of the compounds as well as the evaluation of their mutagenic activity using in vitro reverse mutation assay. Results of determinations at the top section of coke batteries were compared. Mean concentrations of total dust, CTPVs and B/a/P were as follows: 2.06 mg/m3, 0.63 micrograms/m3 in plant A, and 2.77 mg/m3, 0.89 mg/m3 and 0.35 micrograms/m3 in plant B, respectively. All the extracts of particulate matter samples increased the induction of bacterial mutation in both +S9 and -S9 tests. The exposures to mutagenic airborne particulate matter were in the range of 98-683 rev./m3 (-S9): 714-2214 rev./m3 (+S9) in plant A, and 21-496 rev./m3 (-S9); 68-850 rev./m3 (+S9) in plant B. The correlation between mutagenic potential and concentrations of tested agents was insignificant. The coke oven emission seemed to be higher in plant A with side charging of coal.

Non-mutagenicity of thiadiazole-1,3,4 derivatives in Salmonella typhimurium strains.

The Ames mutagenicity assay with Salmonella typhimurium strains (TA97a, TA98, TA100 and TA102) was used to investigate the ability of five dyes (thiadiazole-1,3,4 derivatives) to induce point mutations. The results did not reveal any mutagenic effects of the tested dyes on the S. typhimurium strains. No mutagenic activity was observed in the experimental series with and without exogenous activation.

Genotoxicity assessment of Rokanol B2 and Rokamid R1.

Two surface-active compounds, Rokanol B2 and Rokamid R1, were examined with three types of screening tests: 1. standard Ames test in vitro using S. typhimurium TA97a, TA98, TA100 and TA102 strains; 2. micronucleus test in vivo; 3. sister chromatid exchange (SCE) on bone marrow cells of Balb C mice. Negative results of the testing, in terms of the effects of activity of both the technical preparations on S. typhimurium cells and bone marrow of Balb C mice, were found for both tested chemicals.

Genotoxicity assessment of sulfosuccinate IO-5, Rokamid MRZ 17, Rokacet RZG7P2 and Roksol TL-7 using bacteria and bone marrow rodent cells.

Three short-term tests were used for evaluation of the genotoxic activity of four surface active agents. These were: Ames, Salmonella reversion assay using 4 tester strains (TA97a, TA98, TA100 and TA102), the micronucleus test int the bone marrow of Balb C mice and in vivo sister chromatid exchange (SCE) analysis in SFIS or Balb C mice. The frequency of micronucleated PCEs did not exceed the control values in mice of both sexes after intraperitoneal administration of all four compounds. Three preparations--Sulfosuccinate IO-5, Rokamid MRZ 17 and Rokacet RZG7P2 produced a negative response in Salmonella strains gene mutation assay and SCE induction test in mouse bone marrow cells. The Roksol TL-7 induced frameshift and base-pair substitution mutations in Salmonella tester strains both with and without S9 (prepared from the liver of rats which had been pretreated with Aroclor 1254). Evidently positive results (more than a twofold increase in the number of revertants per plate) were observed in tester strain S. typhimurium TA97a (with and without S9 metabolic activation) and S. typhimurium TA100 (with S9 metabolic activation) at a dose of 0.2 microliter Roksol TL-7 per plate. Roksol TL-7 caused slight increase in the SCE level in mouse bone marrow cells. A significant increase in SCE frequency was observed at doses of 50, 75 and 100 mg/kg.

Mutagenicity of airborne particulates in the rubber industry.

The aim of this work was to evaluate the mutagenic activity of airborne particulate matter in the rubber industry. Air was sucked through Whatman glass-fibre filters with Staplex pumps and adsorbed substances and fume particles were extracted with acetone or toluene for 2 h in a ultrasonic cleaner. After separation of the insoluble solid phase by filtration, solvent was evaporated at a temperature of 70 degrees C in an argon atmosphere. The residue was stored at -20 degrees C. Mutagenicity was determined by the Salmonella plate incorporation assay with the tester strain TA98 and activity is related either to the weight of aerosol (rev mg-1) or to the volume of atmospheric sample (rev m-3). The fumes emitted from the tyre tread line, calender feeding, and tyre vulcanizing processes, showed the highest mutagenic activity (55-211 rev mg-1, + S9). At these and at other workplaces (extruder mill, carbon black station, mixer loading), mutagenic activity related to the volume of air was in the range of 22-158 rev m-3, + S9. The results indicate the need to reduce and monitor mutagenic contamination in order to increase the safety of work in the rubber industry.

Exposure to mutagenic chemicals in foundry and urban environments.

The study was aimed at the estimation of occupational exposure to mutagenic substances in a piston-ring foundry. The following samples were examined: solid phase of aerosol from the foundry and from different places of urban environment together with the foundry workers' urine collected during the 8-hour shift. The mutagenic substances were extracted from the collected material with acetone or concentrated with XAD-2 resin. The mutagenic property was estimated with the Ames' test using S. typhimurium strain TA98 without and with S9 fraction. The highest mutagenic activity was found at the following work-posts: caster, moulder, steerer of an induction furnace, and smelter and in the office rooms and in the flat occupied by heavy smokers. The mutagenic activity of aerosol at some other productive workposts in the foundry was similar to the mutagenic activity of aerosol in the office and flat rooms occupied by nonsmokers or in the street in Lodz. The mutagenic activity of urine from foundry workers was not correlated with the level of the occupational inhalation exposure to the mutagenic substances, however, the mutagenic activity of urine from smoking workers was about 10-20 times higher than from nonsmokers.

[Methods used in evaluating mutagenic and genotoxic properties of chemical compounds. II. The Ames test (an abridged version)]. / Metodyki stosowane do oceny wlasciwosci mutagennych i genotoksycznych zwiazków chemicznych. Czesc II. Plytkowy test Amesa (wersja skrócona).

The paper presents in vitro the technique developed by Ames et al (1.5), applied in screening tests for evaluations of mutagenic effects of chemical substances. As the experimental model in the test use histidine-dependent bacterial cells of Salmonella typhimurium series TA strains. Chemical substances biotransformation is carried out in the presence of microsomal activating system (fraction S9), mostly obtained from rat's liver. Mutagenic activity of chemical substances is measured by an induction of his- mutation reversion in S. typhimurium strains, expressed as number His+ of revertant colonies, as compared to number His+ of spontaneous revertant colonies of a given strain on Petri dishes containing minimal glucose agar after 48-72 hr incubation at 37 degrees C.