[4-[α-[4-(dimethylamino)phenyl]benzylidene]cyclohexa-2,5-dien-1-ylidene]dimethylammonium acetate

Genetic toxicity: in vitro

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:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Not GLP study no international guideline used. Read across from a similar substance which has the same main component and with a different counter ion that doesn't influence the characteristics related to the specific end-point

Data source

Reference

Reference Type:

publication

Title:

Mutagenicity of Malachite Green and Leucomalachite Green in in vitro Tests

Author:

Fessard V., Godard T., Huet S., Mourot A., Poul J.M.

Year:

1999

Bibliographic source:

Journal of Applied Toxicology; J. Appl. Toxicol. 19, 421-430 (1990)

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Malachite Green Oxalate

IUPAC Name:

Malachite Green Oxalate

Details on test material:

- Name of test material: Malachite Green Oxalate
- Free active substance: 70.8%

Method

Species / strain

Species / strain 1

Species / strain / cell type:

other: S. typhimurium TA 97a

Additional strain / cell type characteristics:

not specified

Species / strain 2

Species / strain / cell type:

S. typhimurium TA 98

Additional strain / cell type characteristics:

not specified

Species / strain 3

Species / strain / cell type:

S. typhimurium TA 100

Additional strain / cell type characteristics:

not specified

Species / strain 4

Species / strain / cell type:

S. typhimurium TA 102

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Metabolic activation system:

S9

Test concentrations with justification for top dose:

Test substance:
0.01 , 0.05, 0.1 , 0.5 , 1.0 , 5.0 , 10.0 µg per plate
Malachite green was tested at concentrations ranging from 0.01 to 10 µg per plate and dose ranges were selected from preliminary results on cytotoxicity.

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO 100 µL/plate

Controls

Controls 1

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene (2 µg per plate)

Remarks:

with metabolic activation

Controls 2

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

4-nitroquinoline-N-oxide

Remarks:

without metabolic activation; only in strain TA97, TA98 and TA100

Migrated to IUCLID6: (0.5 µg per plate)

Controls 3

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

mitomycin C

Remarks:

without metabolic activation; only strain TA102

Migrated to IUCLID6: (0.5 µg per plate)

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar
NUMBER OF REPLICATIONS: 3; two independent assays

OTHER:
Salmonella typhimurium strains TA97a, TA98, TA100 and TA102, obtained from B. N. Ames, were maintained from stocks stored at -75°C as described by Maron and Ames

Results and discussion

Test results

Test results 1

Species / strain:

other: S. typhimurium TA 97a

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 TA 98

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 3

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

for doses in the range of 0.1-5 µg/plate the viability of bacteria was 48-71% of the control values

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 4

Species / strain:

S. typhimurium TA 102

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

Additional information on results:

RANGE-FINDING/SCREENING STUDIES:
In a preliminary assay, concentrations of MG higher than 10 µg per plate were found to be highly toxic to Salmonella strain TA100

Any other information on results incl. tables

In a preliminary assay, concentrations of MG higher than 10 µg per plate were found to be highly toxic to Salmonella strain TA100. For doses in the range 0.1–5 µg per plate, the viability of bacteria was 48–71% of the control values, with a significant dose–effect relationship for doses at or higher than 0.5 µg per plate . The results of the mutagenicity studies with MG confirming its cytotoxicity at higher concentrations. In the presence of metabolic activation, however, the toxicity of MG to bacteria was slightly decreased. The compound was found to be highly toxic to bacteria

(TA100 strain) for doses higher than 5 µg per plate. In the present study, however, it was not possible to increase the tested concentrations

above 10 µg per plate without inducing bacterial mortality and precluding the scoring of revertants.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

The results of the mutagenicity studies with MG confirming its cytotoxicity at higher concentrations. Malachite green had no mutagenic activity in any bacterial strains, with and without metabolic activation, for doses at or lower than 10 µg per plate.

Executive summary:

The genotoxic potential of the fungicide malachite green (MG) was assessed in bacteria and mammalian cells using the standard Salmonella typhimurium/Ames and CHO/HGPRT tests. MG was found to be extremely cytotoxic to bacteria. MG don't have any mutagenic activity, in any bacterial strains, in the presence or absence of metabolic activation for doses up to 10 µg per plate.