Methanaminium, N-[4-[[4-(dimethylamino)phenyl]phenylmethylene]-2,5-cyclohexadien-1-ylidene]-N-methyl-, ethanedioate

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro cytogenicity / chromosome aberration study in mammalian cells

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The experiment is scientifically acceptable, nevertheless details about the tested substance composition are missing. Read across from a similar substance which has the same main component and with a different counter ion that does not influence the characteristics related to the specific end-point.

Data source

Reference

Reference Type:

publication

Title:

Studies on the Clastogenic Effects of Biologic Stains and Dyes.

Author:

Au W. and Hsu T. C.

Year:

1979

Bibliographic source:

Environmental Mutagenesis 1: 27-35 (1979)

Materials and methods

Principles of method if other than guideline:

Chinese hamster ovary cell line (CHO) was used for the study. Exponentially growing cultures in 10 ml medium were treated with 20 µM of Malachite Green. Cultures treated with the same amount (0.1 ml) of water or ethanol were used as controls. All cultures were incubated for five hours after the introduction of the test chemical. All cultures were harvested for conventional cytogenetic preparations, stained with Giemsa, and coded.

GLP compliance:

no

Remarks:

pre GLP

Type of assay:

in vitro mammalian chromosome aberration test

Test material

Test material information

Constituent 1

Reference substance name:

Malachite Green

IUPAC Name:

Malachite Green

Method

Species / strain

Species / strain / cell type:

Chinese hamster Ovary (CHO)

Details on mammalian cell type (if applicable):

Chinese hamster ovary cell line (CHO) routinely maintained in the testing aboratory in McCoy 5a medium was used for the study.

Metabolic activation:

without

Test concentrations with justification for top dose:

20 µM/ml

Vehicle / solvent:

Vehicle/solvent used: water or ethanol

Controls

Negative solvent / vehicle controls:

yes

Remarks:

water or ethanol

Details on test system and experimental conditions:

METHOD OF APPLICATION: exponentially growing cultures in 10 ml medium were treated with chemical.

EXPOSURE DURATION: cultures were incubated for 5 hours after the introduction of the test chemical.

DETERMINATION OF CYTOTOXICITY: Colcemid (0.04 µg/ml final concentration) was added to each culture during the last hour of incubation and all cultures were harvested for conventional cytogenetic preparations, stained with Giemsa, and coded.

RECOGNITION OF CHROMOSOMAL ABERRATION: 50 well-spread metaphases were scored for chromosome aberration for each experimental point. The average number of breaks per metaphase was calculated and was used for comparing the clastogenic activities of different compounds.

Results and discussion

Test results

Species / strain:

Chinese hamster Ovary (CHO)

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Additional information on results:

Malchite Green did not show significant increase in induced chromosome damage.
Malachite Green number of breaks per metaphase: 0.26
Water number of breaks per metaphase (4 relicates): 0, 0.04, 0.12, 0.16
Ethanol number of breaks per metaphase (4 relicates): 0.04, 0.08, 0.16, 0.20

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 without metabolic activation

Malchite Green did not show significant increase in induced chromosome damage.

Executive summary:

We have surveyed the clastogenic potential of 12 different groups of stains and dyes totalling 48 compounds. We observed that 18 compounds induced significant increase in chromosome damage.

Chinese hamster ovary cell line (CHO) routinely maintained in the testing laboratory in McCoy 5a medium was used for the study. Exponentially growing cultures in 10 ml medium were treated with 20 µM of Malachite Green. Cultures treated with the same amount (0.1 ml) of water or ethanol were used as controls. All cultures were incubated for five hours after the introduction of the test chemical. Colcemid (0.04 p g / d final concentration) was added to each culture during the last hour of incubation and all cultures were harvested for conventional cytogenetic preparations, stained with Giemsa, and coded. 50 well-spread metaphases were scored for chromosome aberration for each experimental point. The average number of breaks per metaphase was calculated and was used for comparing the clastogenic activities of different compounds.

Malachite Green number of breaks per metaphase: 0.26

Water number of breaks per metaphase (4 relicates): 0, 0.04, 0.12, 0.16

Ethanol number of breaks per metaphase (4 relicates): 0.04, 0.08, 0.16, 0.20

Conclusion

Malchite Green did not show significant increase in induced chromosome damage.