Registration Dossier

Toxicological information

Genetic toxicity: in vitro

Currently viewing:

Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
other: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
weight of evidence
Study period:
1984
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Remarks:
Reliability of the original study was established to be R2: purity below 80 %; strains tested may not detect certain oxidising mutagens, cross-linking agents and hydrazines. Justification for read-across is detailed at section 13.
Justification for type of information:
Justification for read-across is detailed at section 13.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1984
Report Date:
1984

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Target gene:
his
Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Species / strain / cell type:
S. typhimurium TA 1538
Metabolic activation:
with and without
Metabolic activation system:
S9-mix
Test concentrations with justification for top dose:
experiment 1: 100, 500, 2500, 5000 μg/plate.
experiment 2: 500, 2500, 5000, 7500 μg/plate.
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: DMSO
Controlsopen allclose all
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene; 2.5 µg dissolved in DMSO
Remarks:
With metabolic activation
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
9-aminoacridine
N-ethyl-N-nitro-N-nitrosoguanidine
other: 4-nitro-o-phenylenediamide
Remarks:
Without metabolic activation
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar, plate incorporation.
- Duration: 48 h at 37 °C

NUMBER OF REPLICATIONS: 3 test plates per dose or per control.

DETERMINATION OF CYTOTOXICITY: relative total growth.
Evaluation criteria:
In general, a substance to be characterized as positive in the Ames test has to fulfill the following requirements:
- doubling of the spontaneous mutation rate (control),
- dose-response relationship,
- reproducibility of the results.

Results and discussion

Test resultsopen allclose all
Species / strain:
other: TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Genotoxicity:
positive
Remarks:
From 500 µg onwards
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 1538
Metabolic activation:
with and without
Genotoxicity:
positive
Remarks:
From 5000 µg onward.
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Positive controls validity:
valid

Any other information on results incl. tables

Dose µg/plate metabolic activation TA98   TA100   TA1535   TA1537   TA1538
1st exp(a) 2nd exp(b)   1st exp(a) 2nd exp(b)   1st exp(a) 2nd exp(b)   1st exp(a) 2nd exp(b)   1st exp(a) 2nd exp(b)
Mean SD Mean SD   Mean SD Mean SD   Mean SD Mean SD   Mean SD Mean SD   Mean SD Mean SD
0 + 44,5 7,7 47,0 8,5   109,0 2,6 107,5 9,2   17,8 3,8 17,5 0,7   9,5 0,6 7,5 0,7   24,8 1,7 31,5 2,1
20 + 48,3 7,4       119,3 10,3       14,8 6,8       9,5 1,3       28,3 2,2    
100 + 46,8 5,9 46,0 0,0   117,3 5,3 114,5 6,4   14,0 1,6 15,5 4,9   7,5 2,4 11,5 2,1   24,3 3,8 25,0 (c)
500 + 53,0 3,6 44,0 8,5   146,0 15,4 148,5 17,7   14,0 2,4 15,0 7,1   7,0 2,2 8,5 0,7   24,8 6,2 22,0 4,2
2500 + 46,8 7,1 46,0 1,4   254,0 19,9 238,0 7,1   15,5 3,3 21,0 4,2   26,5 7,3 36,5 7,8   20,3 3,0 23,0 9,9
5000 + 45,0 4,1 42,5 4,9   354,3 28,7 306,0 12,7   18,5 3,1 32,5 6,4   45,0 5,5 58,0 11,3   18,3 2,9 27,5 12,0
7500 +     64,0 17,0       378,5 34,6       28,5 3,5       69,0 19,8       27,5 0,7
10 µg 2-Aminoanthracene + 1625,0 132,3 1725,0 134,4   2187,5 165,2 2450,0 141,4   300,8 57,5 394,5 29,0   291,3 18,2 240,0 15,6   1622,5 84,2 1420,0 84,9
                                                   
0 - 29,3 4,9 24,5 0,7   99,5 15,5 106,5 10,6   15,3 2,1 16,0 1,4   8,8 2,6 6,5 0,7   13,3 2,6 11,5 0,7
20 - 30,7 5,8       100,0 15,6       13,3 1,3       7,0 1,8       11,3 2,5    
100 - 31,5 5,9 29,5 2,1   102,8 4,9 106,5 2,1   15,3 3,4 16,5 3,5   7,5 2,5 7,0 1,4   12,5 1,0 13,5 2,1
500 - 43,0 12,9 39,5 9,2   134,0 11,2 153,5 33,2   17,0 3,9 20,0 2,8   13,0 4,2 11,0 2,8   11,3 2,2 17,0 2,8
2500 - 70,0 8,3 78,0 5,7   289,8 30,4 318,5 85,6   21,3 0,5 19,5 2,1   38,0 7,5 33,0 5,7   15,0 2,2 27,5 7,8
5000 - 78,3 16,2 86,5 4,9   415,5 60,7 411,0 62,2   23,5 5,4 32,0 (c)   55,8 8,7 63,5 9,2   15,0 2,2 27,5 7,8
7500       95,5 9,2       571,5 94,0       41,0 8,5       80,0 8,5   26,3 5,6 37,5 0,7
5 µg MNNG -           1875,0 199,4 1845,0 21,2   1317,5 357,6 1595,0 176,8                 58,0 1,4
10 µg 4-Nitro-o-phenylendiamin - 623,5 67,7 907,0 258,8                                 358,5 146,8 642,0 70,7
100 µg 9-amninoacridine -                               698,3 50,3 787,5 7,8          

Applicant's summary and conclusion

Conclusions:
Positive induction of mutation frequence.
Executive summary:

The test was performed according to OECD 471 on five strains of S. typhimurium (TA1535; TA1537; TA98; TA100 and TA1538). A deviation from the guideline was present, since the E.coli strains or the S.typhimurium TA102, as recommended, were not evaluated. These strains should be used in order to evaluate certain oxidising mutagen, cross-linking agents and hydrazines.

The test substance showed a strain-dependent weak to moderate mutagenic effect without metabolic activation from 2500 μg/plate onward. In presence of metabolic activation no mutagenic effect was observed for TA1535, TA1538 and TA98 and a weak mutagenic effect for TA100 and TA1537 (> 2500 μg/plate). With metabolic activation, no or only weak mutagenic activity was determined.