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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:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Data generated according to international accepted valid testing method.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1988
Report Date:
1988

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Qualifier:
according to
Guideline:
OECD Guideline 472 (Genetic Toxicology: Escherichia coli, Reverse Mutation Assay)
GLP compliance:
yes
Remarks:
Pharma Research Toxicology and Pathology, Hoechst AG, Frankfurt, Germany
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material: Glyoxylic acid
- Physical state: liquid
- Lot/batch No.: R 200.306
- Storage condition of test material: dark at 4 °C

Method

Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium, other: S. typhimurium TA 1535, TA 1537, TA 1538, TA 98 and TA 100
Additional strain / cell type characteristics:
not applicable
Species / strain / cell type:
E. coli WP2 uvr A
Additional strain / cell type characteristics:
not applicable
Metabolic activation:
with and without
Metabolic activation system:
microsomal enzyme systems (S-9 fraction) from Aroclor 1254-induced male Sprague-Dawley rat liver
Test concentrations with justification for top dose:
0, 4, 20, 100, 500, 2500, 5000 or 10000 µg/plate
Vehicle / solvent:
- Vehicle/solvent used: water bidest.
Controlsopen allclose all
Untreated negative controls:
yes
Remarks:
sterility control
Negative solvent / vehicle controls:
yes
Remarks:
solvent (background) control
True negative controls:
no
Remarks:
with and without S-9 mix , in TA 1535, TA 1537, TA 1538, TA 98 and TA 100
Positive control substance:
other: 2-aminoanthracene
Remarks:
with S9-mix in all strains tested
Positive controls:
yes
Positive control substance:
benzo(a)pyrene
Remarks:
with S9-mix in all strains tested
Positive controls:
yes
Positive control substance:
other: N-methyl-N-nitrosoguanidine
Remarks:
without S9-mix in WP2uvrA
Positive controls:
yes
Positive control substance:
2-nitrofluorene
Remarks:
without S9-mix in TA 98, TA 1538
Positive controls:
yes
Positive control substance:
9-aminoacridine
Remarks:
without S9-mix in TA 1537
Positive controls:
yes
Positive control substance:
sodium azide
Remarks:
without S9-mix in TA 100, TA 1535
Details on test system and experimental conditions:
METHOD OF APPLICATION:
- in agar (plate incorporation)

DURATION
- Expression time (cells in growth medium): 48-72 hours


SELECTION AGENT :
- minimal amino acid solution 0.05 mM histidine + 0.05 mM biotin (for E.coli histidine was replaced by 0.5 mM tryptophan)

DETERMINATION OF CYTOTOXICITY
- Method: colonies (his+ revertants) were counted





Results and discussion

Test resultsopen allclose all
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
2500 µg/plate and higher concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
E. coli WP2 uvr A
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
2500 µg/plate and higher concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
Control plates without mutagen showed that the number of spontaneous revertant colonies was similar to that described in the literature. All the positive control compounds gave the expected increase in the number of revertant colonies.

Toxicity: The test compound proved to be toxic to most of the bacterial strains at 2500 µg/plate.
5000 µg/plate was chosen as top dose level for the mutagenicity study.

Mutagenicity: In the absence of the metabolic activation system the test compound did not show a dose dependent increase in the number of revertants in any of the bacterial strains. Also in the presence of a metabolic activation system, treatment of the cells with Glyoxylic acid did not result in relevant increases in the number of revertant colonies.
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
Executive summary:

In a reverse gene mutation assay (Müller W, 1988) in bacteria strains TA 1535, TA 1537, TA 1538, TA 98 and TA 100 of S. typhimurium and WP2 uvrA of E. Coli were exposed to Glyoxylic Acid at concentrations of 0, 4, 20, 100, 500, 2500, 5000 or 10000 µg/plate (3 plates/dose) in the presence and absence of mammalian metabolic activation applying the standard plate method. Cytotoxicity was observed at 2500 µg/plate and higher doses. The positive controls induced the appropriate responses in the corresponding strains. There was no evidence of induced mutant colonies over background.

This study is classified as acceptable and satisfies the requirement for test guideline OECD 471 for in vitro mutagenicity (bacterial reverse gene mutation) data.