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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1983-07-06 to 1983-08-17
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1983
Report date:
1983

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Version / remarks:
adopted 1983
Deviations:
yes
Remarks:
The highest dose tested was 10,000 µg/plate and, thus, exceeding the maximum test concentration of 5,000 µg/plate as recommended by the Guideline.
Qualifier:
according to guideline
Guideline:
EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)
Deviations:
yes
Remarks:
The highest dose tested was 10,000 µg/plate and, thus, exceeding the maximum test concentration of 5,000 µg/plate as recommended by the Guideline.
GLP compliance:
yes (incl. QA statement)
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
1,3-dihydroxyacetone
EC Number:
202-494-5
EC Name:
1,3-dihydroxyacetone
Cas Number:
96-26-4
Molecular formula:
C3H6O3
IUPAC Name:
1,3-dihydroxyacetone
Details on test material:
Purity: 99.0 %

Method

Target gene:
His Operon
Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 98
Details on mammalian cell type (if applicable):
his D 3052, uvrB, rfa + R-factor (pKM101)
Species / strain / cell type:
S. typhimurium TA 100
Details on mammalian cell type (if applicable):
his G 46, uvrB, rfa + R-factor (pKM101)
Species / strain / cell type:
S. typhimurium TA 102
Details on mammalian cell type (if applicable):
his G428, rfa + R-factor (pKM101)
Species / strain / cell type:
S. typhimurium TA 1535
Details on mammalian cell type (if applicable):
his G 46, uvrB, rfa
Species / strain / cell type:
S. typhimurium TA 1537
Details on mammalian cell type (if applicable):
his C 3076, uvrB, rfa
Metabolic activation:
with and without
Metabolic activation system:
10% rat liver homogenate (S9 mix) with standard co-factors with metabolic activation (Aroclor)
Test concentrations with justification for top dose:
1st and 2nd test: 50, 250, 1250, 2500, 5000, and 10000 µg/plate
Vehicle / solvent:
DMSO
Controlsopen allclose all
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
benzo(a)pyrene
other: 2-Aminoanthracene
Remarks:
with S9
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
9-aminoacridine
2-nitrofluorene
N-ethyl-N-nitro-N-nitrosoguanidine
methylmethanesulfonate
mitomycin C
other: N-Methyl-N-nitro-N-nitrososguanidine
Details on test system and experimental conditions:
NUMBER OF REPLICATIONS:
- Number of cultures per concentration: 4 plates per test concentrations, 8 (2x 4) plates per solvent control
- Number of independent experiments: 2

METHOD OF TREATMENT/ EXPOSURE:
- Test substance added in agar (plate incorporation)
Evaluation criteria:
No evaluation criteria are provided in the original report. For the reevaluation of the results of this study the following criteria are taken into account:
A test material was to be defined as positive or mutagenic in this assay if
- a biologically relevant increase in the mean number of revertants above a threshold of 2-fold (TA 98, TA 100, TA 102) or 3-fold (TA 1535, TA 1537) as compared to the concurrent negative controls is observed.
- an increase exceeding the threshold at only one concentration is considered as biologically meaning ful if reproduced in a second independent experiment
- a concentration-dependent increase is considered biologically meaningful if the threshold is exceeded at more than one concentration
Statistics:
no

Results and discussion

Test resultsopen allclose all
Key result
Species / strain:
S. typhimurium TA 98
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with and without
Genotoxicity:
positive
Remarks:
at concentrations larger than 2500 µg/plate
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 102
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 1535
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 1537
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Positive controls validity:
valid

Any other information on results incl. tables

The test material was examined for mutagenic activity in two series of in vitro microbial assays employing Salmonella typhimurium indicator organisms. The substance was tested with and without the presence of a metabolic activation system, i.e. liver microsomal enzyme preparations from Aroclor-induced rats.

The test material was tested over a series of concentrations. The choice of the concentration range was mainly influenced by the endeavor to achieve a toxic effect in the highest concentration. Such a toxic effect is generally considered important in this test system. This effect was not obtained in the present trials: No toxicity and no precipitation were observed up to the highest dose tested at both experiments.

During the routinely conducted microscopic examination of the plates no toxic effect was detected. The dose range employed for the evaluation of this compound was from 50 to 10000µg per plate, i.e. the highest dose exceeded the maximum test material concentration as recommended by the OECD guideline.

The results of the tests conducted on the test material in the absence and presence of a metabolic system were negative for Salmonella typh. TA 98, TA 102, TA 1535, and TA 1537. The repeat tests were also negative.

With the tester strains Salmonella typhimurium TA 100 the observed increase in the number of revertant colonies was interpreted as a positive result.

The validity of the mutation assay can be assessed by the results obtained for the positive and negative controls. The negative control mutant frequencies were all in the normal range, and the positive control compounds yielded normal mutant frequencies that were greatly in excess of the background.

Applicant's summary and conclusion

Conclusions:
Based on the results of this study, the test material is considered to be weakly positive in this bacterial reverse mutation assay.
Executive summary:

The investigations were performed using Salmonella typhimurium TA 100, TA 102, TA 98, TA 1535 and TA 1537 as tester strains. The mutagenic potential was examined in the plate incorporation test with and without addition of a liver postmitochondrial fraction as the in vitro metabolizing system (S-9; male rats, induced with Aroclor 1254).

Concentrations: 50, 250, 1250, 2500, 5000, and 10000 µg/plate.

2-Aminoanthracene, 9-aminoacridine, benzo(a)pyrene, daunomycin, 1-ethyl-2-nitro-3-nitrosoguanidine, methyl methanesulfonate, N-methyl-N-nitro-N-nitro­soguanidine, mitomycin c, and 2-nitrofluorene served as positive controls for testing the bacteria and the induced S-9 preparation.

With and without addition of S-9 as the metabolizing system, the test material did show mutagenic activity with Salmonella typhimurium TA 100 in the concentration range used. With Salmonella typhimurium TA 98, TA 102, TA 1535 and TA 1537 no mutagnic activity was found. With Salmonella typhimurium TA 100 the number of revertant colonies was increased 2.4 - 3.8 -fold. The maximum concentration level in this study exceeded the highest test concentration as recommended by the current OECD-Guideline for this system. Toxicity and precipitation was not observed up to the highest dose tested.

The substances used as positive controls showed normal reversion properties of all strains and good metabolic activity of the S-9 mix used.