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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:
1978-05
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1978
Report Date:
1978

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
Only 4 strains tested.
GLP compliance:
no
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Substance type: organic
- Physical state: solid

Method

Target gene:
his locus
Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Metabolic activation system:
rat liver microsomes and co-factors
Test concentrations with justification for top dose:
1, 3, 9, 27, and 81 µg/0.1 mL
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: acetone- Justification for choice of solvent/vehicle: the test substance is insoluble in water
Controls
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: see below
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Preincubation period: none
- Exposure duration: 48 h

SELECTION AGENT (mutation assays): growth in absence of histidine

NUMBER OF CELLS EVALUATED:
In the experiments with and without the addition of microsomal activation mixture, three Petri dishes were prepared per strain and per group

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth

CONTROLS:
Positive control experiments were carried out simultaneously with the following substances:
1) for Strain TA 1535: N-methyl-N'- nitro-N-nitrosoguanidine, 3 and 5 µg/0.1 ml phosphate buffer
2) for Strain TA 1537: 9(5)aminoacridine hydrochloride monohydrate, 25, 50, and 100 µg/0.l ml DMSO
3) for Strain TA 98: daunoblastin, 2.5, 5, and 10 µg/0.l ml phosphate buffer
4) for Strain TA 100: 4-nitroquinoline-N-oxide, 0.0625, 0.125, and 0.25 µg/0.l ml phosphate buffer
The activation mixture was tested with Strain TA 1535 and cyclophosphamide 100 and 250 µg/0.1 ml phosphate buffer
Evaluation criteria:
The test substances was considered to be non-mutagenic if the colony count in relation to the negative control was not doubled at any concentration
Statistics:
arithmetic mean

Results and discussion

Test results
Species / strain:
other: S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
Positive controls validity:
valid

Any other information on results incl. tables

SUMMARY OF EXPERIMENTAL RESULT

TA 98 TA 100 TA 1535 TA 1537
Dose (µg/0.1 ml) -S9 +S9 -S9 +S9 -S9 +S9 -S9 +S9
solvent control 13 26 78 74 8 13 6 9
1 17 17 80 84 11 14 7 10
3 17 32 75 84 11 14 4 8
9 17 26 79 87 10 12 6 9
27 21 29 78 92 10 12 9 9
81 16 28 66 84 10 13 8 10
positive controls:
solvent control 25 74 14 11 5
concentration A 63 281 68 296 43
concentration B 211 398 1067 549 396
concentration C 229 707 - >1900
solvent control 19
concentration A 256
concentration B 478

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):negative with and without metabolic activationIn the experiments performed with and without microsomal activation, comparison of the number of histidine-prototrophic mutants in the controls and after treatment with test material revealed no marked differences.