Multi constituent substance

Genetic toxicity: in vitro

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: Study performed according to OECD guideline 471 in compliance to GLP.

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

Reference 2

Reference Type:

other: Published secondary source

Title:

Unnamed

Year:

2014

Report date:

2014

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Multi constituent substance

EC Number:

916-604-0

IUPAC Name:

Multi constituent substance

Details on test material:

Test substance : Basic Brown 17 (COLIPA number B007)
Batch number : 64960101
Methylsulphate anion : 11.6%
Chloride ion : 3.3%
Water : 6.5%
Basic Red 118 : 4.5%
Purity : 94.2% (HPLC)

Method

Species / strain

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with and without

Metabolic activation system:

rat liver

Test concentrations with justification for top dose:

Experiment I : 3, 10, 33, 100, 333, 1000, 2500, 5000 ug/plate without and with metabolic activation

Vehicle / solvent:

Deionised water

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

not specified

Details on test system and experimental conditions:

Treatment
Experiment I : Direct plate incorporation with 48 hours incubation without and with metabolic activation.
Test concentrations were based on the level of toxicity in a preliminary toxicity test with strains TA98 and TA100 both in the absence and presence of metabolic activation. Toxicity was evaluated for 8 concentrations up to the prescribed maximum concentration of 5000 ug/plate on the basis of a reduction in the number of spontaneous revertant colonies and/or clearing of the bacterial background lawn. Since in the pre-experiment evaluable plates were obtained for five concentrations or more in the strains used the pre-experiment is reported as part of the main experiment (I).

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium, other: TA100, TA102, TA1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium, other: TA98, TA1537

Metabolic activation:

with and without

Genotoxicity:

positive

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

Test item treatment resulted in a biologically relevant and dose dependent increase in the number of revertant colonies in strains TA98 and TA1537. At the two highest concentrations the number of revertant colonies was reduced due to overlapping toxic effects.

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):
positive

Under the experimental conditions employed the test item (Basic Brown 17) was mutagenic in this bacterial gene mutation test.

Executive summary:

The study was performed to investigate the potential of Basic Brown 17 to induce gene mutations according to the plate incorporation test using the Salmonella typhimurium strains TA1535, TA1537, TA98, TA100 and TA102. The assay was performed 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/main experiment I : 3, 10, 33, 100, 333, 1000, 2500, 5000 ug/plate. The plates incubated with the test item showed reduced background growth in nearly all strains used at higher concentrations with and without metabolic activation. Toxic effects, evident as a reduction in the number of revertants, occurred in all strains, except in strain TA1535 with and without metabolic activation. Substantial and dose dependent increases in revertant colony numbers were observed following treatment with Basic Brown 17 in strains TA1537 and TA98 in the presence and absence of metabolic activation. Appropriate reference mutagens were used as positive controls and showed a distinct increase of induced revertant colonies. Under the experimental conditions employed, the test item did induce gene mutations by frameshifts in the genome of strains TA1537 and TA98 in the presence and absence of metabolic activation. Basic Brown 17 is considered to be mutagenic in this Salmonella typhimurium reverse mutation assay.