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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Remarks:
Type of genotoxicity: gene mutation
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: The test procedure cannot be subsumed under a testing guideline, nevertheless are well documented and scientifically acceptable. The test was not performed on GLP. The OECD recommended combination of strains was tested.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1980
Report Date:
1980

Materials and methods

Principles of method if other than guideline:
The test was to be carried out for the purpose of checking the back mutation from Histidine requisite to non-requisite in Salmonella Tryphimurium and back mutation from Tryptophane requisite to non-requisite in Caliform Bacilli.
GLP compliance:
not specified
Type of assay:
bacterial gene mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Additional strain / cell type characteristics:
other: Histidine requisite strain.
Species / strain / cell type:
S. typhimurium TA 1538
Additional strain / cell type characteristics:
other: Histidine requisite strain.
Species / strain / cell type:
E. coli WP2 uvr A
Additional strain / cell type characteristics:
other: Tryptophane requisite strain.
Metabolic activation:
with and without
Metabolic activation system:
S-9 additive
Test concentrations with justification for top dose:
5000, 1000, 500, 100, 50 and 10 µg/plate.
Controls
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Positive control substance:
9-aminoacridine
2-nitrofluorene
N-ethyl-N-nitro-N-nitrosoguanidine
other: AF2, 4-nitro-o-phenylenediamine and 2-aminoanthracene.
Remarks:
- S9: TA98, TA 100 and WP2 uvrA AF2; TA 1537 9-AC, TA 1538 4-NOPD; TA 1535 ENNG. + S9: 2-AA all strains
Details on test system and experimental conditions:
PREPARATION OF SPECIMEN BACILLI
The specimen bacilli solution was made by supplementing 0.5 % NaCl, inoculating specimen bacilli into L-form test tube which contains nutrient broth (Difco), and cultivating them with two-way 16 hour shaking at the temperature of 37 °C.

TEST OPERATION
Plate Incorporation Method.
In the small tube, the specimen bacill solution 0.1 ml , specimen solution 0. 1 ml and phosphate-buffered solution 0.5 ml (S-mixed solution) 0.5ml for the metabolic activation test) were well mixed with 2 ml top agar and the mixture was put on the base agar plate to harden it.
The culture was to be made for 48 hours at 37 °C, and the generating mutation colony was counted.

REAGENTS
1) Top Agar
2) S-9 mixed solution
3) base agar







Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium TA 1538
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Positive controls validity:
valid
Additional information on results:
All six strains (Salmonella Typhinurium TA 1535, TA 100, TA 1537, TA 1538, TA 98; "Escherichia coll WP2 uvrA with the dose of 10 - 5000 µg both in the Direct and the Metabolic Activation Tests, remarkable increase in the mutation colony was not admitted.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative with and without metabolic activation

The test item is not judged to possess mutationality concerning the testings conducted with it.
Executive summary:

Method

The test item was evaluated for mutagenic potential in assays for gene mutation, without and with metabolic activation, in five tester strains of Salmonella thimurium and Escherichia coli WP2 avr A at the concentration of 5,000, 1,000, 500, 100, 50 and 10 µg/plate.

The test was to be carried out for the purpose of checking the back mutation from Histidine requisite to non-requisite in Salmonella Tryphimurium and back mutation from Tryptophane requisite to non-requisite in Caliform Bacilli.

Results

In all the strains tested (Salmonella Typhinurium TA 1535, TA 100, TA 1537, TA 1538, TA 98; Escherichia coll WP2 uv rA) with the dose of 10 - 5000 µg both in the Direct and the Metabolic Activation Tests, remarkable increase in the mutation colony was not admitted.

Conclusion

The test item is not judged to possess mutationality concerning the testings conducted with it.