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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:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
The test parameters documented do not totally comply with the specific testing guideline, but they are sufficient to accept the data. The test was conducted according to internationally accepted testing guidelines. Details about the read across approach are reported in the summary.

Data source

Reference
Reference Type:
publication
Title:
Safety Evaluation of a Lipase Expressed in Aspergillus oryzae.
Author:
Greenough R.J., Perry C.J. and Stavnsbjerg M.
Year:
1996
Bibliographic source:
Fd Chem. Toxic. Vol. 34, No. 2, pp. 161-166, 1996

Materials and methods

Principles of method if other than guideline:
The test substance was examined for mutagenic activity using Salmonella typhimurium strains TA1535, TA100, TA1537 and TA98 and Escherichia coli WP2uvrA, both in presence and in absence if metabolic activation. Bacteria were exposed to five doses of test material in a phosphate buffered nutrient broth for 3 hr.
GLP compliance:
not specified
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2
Metabolic activation:
with and without
Metabolic activation system:
a liver preparation from male rats pretreated with Aroclor 1254 and cofactors required for mixed function oxidase activity (S-9 mix)
Test concentrations with justification for top dose:
Bacteria were exposed to five doses of test material from 0.1 to 10 mg/ml incubation mixture at half-log intervals.
Details on test system and experimental conditions:
Lipase activity was removed from the test material by ultrafiltration before testing because of its destructive action on the metabolic activation system (S-9) and the bacterial cell wall.
A liquid culture assay was used.
Bacteria were exposed to five doses of test material in a phosphate buffered nutrient broth for 3 hr.
After incubation the test substance was removed by centrifugation before plating.
The numbers of revertants to prototrophy and viable cells were estimated.

The sensitivity of the individual bacterial strains was confirmed by notable increases in the number of revertant colonies induced in similar liquid conditions by diagnostic mutagens.

Results and discussion

Test results
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:
not specified
Additional information on results:
No dose-related increases in revertants to phototrophy were obtained in any of the tests performed; all results were confirmed in an independent experiment and it was concluded that there were no indications of mutagenic activity in the presence or absence of metabolic activation.
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

No indications of mutagenic activity in the presence or absence of metabolic activation.
Executive summary:

The test substance was examined for mutagenic activity using Salmonella typhimurium strains TA1535, TA100, TA1537 and TA98 and Escherichia coli WP2uvrA. The test substance activity was removed from the test material by ultrafiltration before testing because of its destructive action on the metabolic activation system (S-9) and the bacterial cell wall. A liquid culture assay was used.

Bacteria were exposed to five doses of test material in a phosphate buffered nutrient broth for 3 hr. After incubation the test substance was removed by centrifugation before plating. The numbers of revertants to prototrophy and viable cells were estimated.

The sensitivity of the individual bacterial strains was confirmed by notable increases in the number of revertant colonies induced in similar liquid conditions by diagnostic mutagens.

No dose-related increases in revertants to phototrophy were obtained in any of the tests performed; all results were confirmed in an independent experiment and it was concluded that there were no indications of mutagenic activity in the presence or absence of metabolic activation.

Conclusion

No indications of mutagenic activity in the presence or absence of metabolic activation.