Registration Dossier

Toxicological information

Genetic toxicity: in vitro

Currently viewing:

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:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study and GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2008
Report Date:
2008

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
GRO 266
SAT 080010
Batch No.: Gro-Rn-9810-003

Method

Species / strain
Species / strain / cell type:
other: Salmonella typhimurium: TA 1535, TA 1537, TA 98, TA 100 and TA 102
Additional strain / cell type characteristics:
other: not applicable
Metabolic activation:
with and without
Metabolic activation system:
rat liver S9 induced
Test concentrations with justification for top dose:
Experiment I: 3, 10, 33, 100, 333, 1000, 2500 and 5000 µg/plate
Experiment II: 33, 100, 333, 1000, 2500 and 5000 µg/plate
Vehicle / solvent:
DMSO
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: see remarks
Remarks:
-S9: Sodium Azide, 4-NOPD, MMS; +S-9: 12-Aminoanthracene, 2-AA
Details on test system and experimental conditions:
Method of application: in medium; in agar (plate incorporation); preincubation; suspension

Number of replications: 3 plates
Evaluation criteria:
A test item is considered as a mutagen if a biologically relevant increase in the number of revertants exceeding the treshold of twice (strains TA 98, TA 100 and TA 102) or thrice (strains TA 1535 and TA 1537) the colony count of the corresponding solvent control is observed.
A dose dependent increase is considered biologically relevent if the treshold is exceed at more than one concentration.
An increase exceeding the treshold at only one concentration is judged as biologically relevant if reproduced in an independent second
experiment.
A dose dependent increase in the number of revertant colonies below the treshold is regarded as an indication of a mutagenic potential if reproduced in an independent second experiment. Howewer, whenever the colony counts remain within the historical range of negative and solvent
controls such an increase is not considered biologically relevant.
Statistics:
According to the OECD guideline 471, a statistical analysis of the data is not mandatory.

Results and discussion

Test results
Species / strain:
S. typhimurium, other: TA 1535, TA 1537, TA 98, TA 100, TA 102
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
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

In conclusion, It can be stated that during the described mutagenicity test and under the experimental conditions reported, the test item did not
induce gene mutatuions by base pair changes or frameshift in the genome of the strains used.
Therefore, GRO 266 is consideed to be non-mutagenic in this Salmonella typhimurium reverse mutation assay.
Executive summary:

This study was performed to investigate the potential of GRO 266 to induce gene mutations according to the plate incorporation test (experiment I) and the pre-incubation test (experiment II) using the Salmonella typhimurium strains TA 1535, TA 1537, TA 98, TA 100, TA 102.

The assay was performed in two independent experiments both with and without liver microsomal activation. Each concentration, including the controls, was tested in triplicate. The test item was tested at the following concentrations:

Pre-Experiment/Experiment I: 3, 10, 33, 100, 333, 1000, 2500 and 5000 µg/plate

Experiment II: 33, 100, 333, 1000, 2500 and 5000 µg/plate

The plates incubated with the test item showed normal backround growth up to 5000 µg/plate with and without S9 mix in all strains used.

No toxic effects, evident as a reduction in the number of revertants (below the indication factor of 0.5), occured in the test groups with and without metabolic activation.

No substantial increase in relevant colony numbers of any of the five tester strains was observed following treatment with GRO 266 at any dose level, neither in the presence nor absence of metabolic activation (S9 mix). There was also no tendency of higher mutation rates with increasing concentrations in the range below the generally acknowledged border of biological relevance.

Appropriate reference mutagens were used as positive controls and showed a distinct increase of induced revertant colonies.