Registration Dossier

Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
August 09, 2017 - August 17, 2017
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2017

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Qualifier:
according to guideline
Guideline:
EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)
GLP compliance:
yes (incl. QA statement)
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
α-methyl-1H-imidazole-1-ethanol
EC Number:
253-668-2
EC Name:
α-methyl-1H-imidazole-1-ethanol
Cas Number:
37788-55-9
Molecular formula:
C6H10N2O
IUPAC Name:
1-(1H-imidazol-1-yl)propan-2-ol
Test material form:
liquid

Method

Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 97
Species / strain / cell type:
S. typhimurium TA 98
Species / strain / cell type:
S. typhimurium TA 100
Species / strain / cell type:
S. typhimurium TA 102
Species / strain / cell type:
S. typhimurium TA 1535
Metabolic activation:
with and without
Test concentrations with justification for top dose:
In the first experiment, the test item (dissolved in DMSO) was tested up to concentrations of 5 µL/plate in the absence and presence of S9-mix in the strains TA97a, TA98, TA100, TA102 and TA1535 using the plate incorporation method. Based on the first experiment, the test item was tested up to concentrations of 5 μL/plate in the absence and presence of S9-mix in all bacteria strains using the pre-incubation method.
Vehicle / solvent:
solvent used: DMSO
Controls
Untreated negative controls:
yes
Remarks:
water and DMSO
Negative solvent / vehicle controls:
yes
Remarks:
water and DMSO
True negative controls:
yes
Remarks:
water and DMSO
Positive controls:
yes
Positive control substance:
sodium azide
benzo(a)pyrene
other: 4-Nitro-1,2-phenylene diamine; 2-Amino-anthracene
Details on test system and experimental conditions:
All Salmonella typhimurium strains were obtained from TRINOVA BioChem GmbH (batch: TA97a: 4997D, TA98: 5011D, TA100: 4996D, TA102: 4982D, TA1535: 5012D) and were stored as lyophilizates in the refrigerator at 2-8 °C.
The lyophilizates were used to prepare permanent cultures which were filled into vials and stored at < - 75 °C.
Evaluation criteria:
A substance is considered to have mutagenic potential, if a reproducible increase of re-vertant colonies per plate exceeding an increase factor of 2 in at least one strain can be observed. A concentration-related increase over the range tested is also taken as a sign of mutagenic activity.

Results and discussion

Test resultsopen allclose all
Key result
Species / strain:
S. typhimurium TA 97
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not specified
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 98
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not specified
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not specified
Vehicle controls validity:
valid
Untreated negative 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:
not specified
Vehicle controls validity:
valid
Untreated negative 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:
not specified
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
Two test were conducted using the plate incorporation method in the first test and the pre-incubation method in the second test. In both test the maximum doese tested was 5 µL/plate for all strains. Nearly all determined values for the spontaneous revertants of the negative controls were in the normal range of the test laboratory. All positive controls (diagnostic mutagens) showed mu-tagenic effects with and without metabolic activation and nearly all were within the histori-cal control data ranges.

Any other information on results incl. tables

Table 1: Mean Revertants First Experiment

Strain  TA97a  TA100  TA98  TA98  TA100  TA100  TA102  TA102  TA1535  TA1535 
Induction  -S9  +S9  -S9  +S9  -S9  +S9  -S9  +S9  -S9  +S9 
Demin. water  Mean  83  69  52  50  82  102  356  345  24  22 
sd  6.7  5.0  5.2  10.7  20.6  18.5  62.9  72.6  8.0  7.5 
DMSO  Mean  85  78  43  39  110  101  257  324  21  21 
sd  5.6  13.6  5.5  11.9  6.0  21.2  26.6  20.8  0.6  5.3 
Positive Controls*  Mean  343  657  560  487  404  1001  689  1083  265  132 
sd  35.9  24.1  146.0  123.3  17.4  0.0  60.2  400.0  59.5  15.2 
f(I)  4.04  8.42  13.02  12.49  4.93  9.91  2.68  3.34  11.04  6.29 
5 μL/plate  Mean  83  83  40  40  84  115  411  425  23  24 
sd  15.3  2.0  10.1  13.2  2.0  28.7  44.1  62.0  2.6  1.2 
f(I)  0.98  1.06  0.93  1.03  0.76  1.14  1.60  1.31  1.10  1.14 
1.5 μL/plate  Mean  84  76  51  34  94  130  343  417  25  24 
sd  7.6  14.5  3.0  0.6  14.0  15.0  23.4  26.6  4.7  4.0 
f(I)  0.99  0.97  1.19  0.87  0.85  1.29  1.33  1.29  1.19  1.14 
0.5 μL/plate  Mean  62  77  34  38  119  122  361  313  19  19 
sd  8.6  10.1  5.3  4.5  5.8  3.5  81.2  35.9  1.0  3.6 
f(I)  0.73  0.99  0.79  0.97  1.08  1.21  1.40  0.97  0.90  0.90 
0.15 μL/plate  Mean  79  82  37  43  108  117  303  285  21  24 
sd  23.1  11.0  2.5  4.5  30.0  19.6  53.3  36.1  2.0  0.6 
f(I)  0.93  1.05  0.86  1.10  0.98  1.16  1.18  0.88  1.00  1.14 
0.5 μL/plate  Mean  88  94  50  38  112  126  331  327  20  21 
sd  6.1  22.0  2.5  1.2  36.2  3.5  89.9  56.6  1.0  3.5 
f(I)  1.04  1.21  1.16  0.97  1.02  1.25  1.29  1.01  0.95  1.00 

f(I) = increase factor

* Different positive controls were used

Table 2: Mean Revertants Second Experiment

Strain  TA97a  TA97a  TA98  TA98  TA100  TA100  TA102  TA102  TA1535  TA1535 
Induction  -S9  +S9  -S9  +S9  -S9  +S9  -S9  +S9  -S9  +S9 
Demin. water  Mean  80  117  38  37  97  101  292  303  16  17 
sd  16.9  6.1  3.5  8.9  23.5  21.9  40.6  66.5  3.5  8.9 
DMSO  Mean  93  123  45  40  95  93  311  337  15  20 
sd  12.2  3.1  9.3  7.0  26.0  18.1  19.7  73.8  4.7  8.3 
Positive Controls*  Mean  656  607  477  421  413  531  1301  684  331  92 
sd  228.7  70.5  80.1  12.2  44.1  163.2  112.1  4.0  76.4  14.4 
f(I)  7.05  4.93  10.60  10.53  4.26  5.71  4.18  2.03  20.69  4.60 
5 μL/plate  Mean  105  115  30  35  108  122  323  277  22  20 
sd  11.5  6.1  8.7  2.5  15.1  4.0  54.3  46.7  3.2  4.9 
f(I)  1.13  0.93  0.67  0.88  1.14  1.31  1.04  0.82  1.47  1.00 
2.5 μL/plate  Mean  145  117  36  36  95  99  317  356  22  18 
sd  34.5  26.6  2.6  4.0  9.5  16.2  23.1  86.5  2.9  1.5 
f(I)  1.56  0.95  0.80  0.90  1.00  1.06  1.02  1.06  1.47  0.90 
1.25 μL/plate  Mean  144  126  35  30  98  84  248  311  19  22 
sd  20.0  7.2  9.2  11.5  15.6  3.5  28.0  46.7  4.5  3.2 
f(I)  1.55  1.02  0.78  0.75  1.03  0.90  0.80  0.92  1.27  1.10 
0.63 μL/plate  Mean  111  96  41  36  91  96  263  287  18  21 
sd  2.6  20.9  6.7  11.2  14.5  15.9  37.2  36.3  3.5  3.6 
f(I)  1.19  0.78  0.91  0.90  0.96  1.03  0.85  0.85  1.20  1.05 
0.31 μL/plate  Mean  88  114  33  36  85  103  275  265  15  21 
sd  7.8  20.2  5.7  11.6  3.1  14.2  86.2  89.6  4.5  3.0 
f(I)  0.95  0.93  0.73  0.90  0.89  1.11  0.88  0.79  1.00  1.05 
0.16 μL/plate  Mean  96  76  30  28  80  102  311  261  20  15 
sd  10.0  11.1  3.8  4.7  1.2  12.8  61.1  28.1  2.3  2.3 
f(I)  1.03  0.62  0.67  0.70  0.84  1.10  1.00  0.77  1.33  0.75 

f(I) = increase factor

* Different positive controls were used

Applicant's summary and conclusion

Conclusions:
No significant increase of the number of revertant colonies in the treatments with and with-out metabolic activation could be observed. No concentration-related increase over the tested range was found. Based on the results of this study it is concluded that N-(2-hydroxypropyl)imidazole is not mutagenic in the Salmonella typhimurium strains TA97a, TA98, TA100, TA102 and TA1535 in the absence and presence of metabolic activation under the experimental conditions in this study.