Sodium 3-[[3-methoxy-4-[(4-methoxyphenyl)azo]phenyl]azo]benzenesulphonate

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Experiment start date - 16 October 1984; Experiment completion date - 12 November 1984; Study completion date - 29 November 1984.

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1984

Report date:

1984

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

GLP compliance:

no

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Sodium 3-[[3-methoxy-4-[(4-methoxyphenyl)azo]phenyl]azo]benzenesulphonate

EC Number:

264-129-6

EC Name:

Sodium 3-[[3-methoxy-4-[(4-methoxyphenyl)azo]phenyl]azo]benzenesulphonate

Cas Number:

63405-85-6

Molecular formula:

C20H18N4O5S.Na

IUPAC Name:

sodium 3-({3-methoxy-4-[(4-methoxyphenyl)diazenyl]phenyl}diazenyl)benzenesulfonate

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

None

Specific details on test material used for the study:

Name: FAT 20004/G
Purity: 98.4 %
Batch no: DM 4694/13/1

Method

Target gene:

Histidine gene

Species / strain

Species / strain / cell type:

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

Details on mammalian cell type (if applicable):

The bacteria on which the tests were performed were the following histidine-auxotrophic strains of Salmonella typhimurium: TA 98, TA 100, TA 102, TA 1535 and TA 1537 (origin: Prof.B. Ames, Berkeley, U.S.A.).

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Metabolic activation system:

S9 mix

Test concentrations with justification for top dose:

With and without metabolic activation: 20, 78, 313, 1250 and 5000 µg/0.1 ml.

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO

Controls

Controls 1

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: daunorubicin- HCl

Remarks:

for TA 98 without -S9

Controls 2

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

4-nitroquinoline-N-oxide

Remarks:

for TA 100 without -S9

Controls 3

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

mitomycin C

Remarks:

for TA 102: without -S9

Controls 4

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

for TA 1535 without -S9

Controls 5

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: aminoacridine hydrochloride monohydrate

Remarks:

TA 1537 without -S9

Controls 6

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene

Remarks:

strains TA 98, TA 100, TA 1537, TA 102 with activation mixture

Controls 7

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

cyclophosphamide

Remarks:

with strain TA 1535 with activation mixture

Results and discussion

Test results

Species / strain:

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

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

In the experiments performed without and with microsomal activation none of the tested concentrations of FAT 20004/G led to an increase in the incidence of histidine-prototrophic mutants in comparison with the controls. After exposure to FAT 20004/G at the highest concentration in the experiments without and with microsomal activation, the number of histidine-prototrophic mutants was reduced, as a result of the inhibitory effect of the substance on the growth of the bacteria.

Any other information on results incl. tables

SALMONELLA/MAMMALIAN-MICROSOME MUTAGENICITY TEST EXPERIMENTS WITHOUT MICROSOMAL ACTIVATION NUMBER OF BACK-MUTANT COLONIES PER PLATE (ARITHMETIC MEAN)

Strain	TA 98	TA 100	TA 102	TA 1535	TA 1537
Control	25	160	285	12	4
20 µg/0.1 ml	23	200	299	9	7
78 µg/0.1 ml	25	181	285	11	6
313 µg/0.1 ml	21	168	301	11	6
1250 µg/0.1 ml	18	164	288	6	7
5000 µg/0.1 ml	14	45	166	8	4
Positive control (Vehicle)	26	168	269	13	9
Positive control (Concentration 1)	309	916	916	790	43
Positive control (Concentration 2)	576	1464	2431	1236	835

 

 SALMONELLA/MAMMALIAN-MICROSOME MUTAGENICITY TEST EXPERIMENTS WITH MICROSOMAL ACTIVATION NUMBER OF BACK-MUTANT COLONIES PER PLATE (ARITHMETIC MEAN)

Strain	TA 98	TA 100	TA 102	TA 1535	TA 1537
Control	53	162	406	12	13
20 µg/0.1 ml	66	162	380	12	8
78 µg/0.1 ml	53	155	407	12	9
313 µg/0.1 ml	54	167	393	13	9
1250 µg/0.1 ml	47	154	416	9	8
5000 µg/0.1 ml	36	81	216	13	6
Positive control (Vehicle)	43	143	345	9	7
Positive control (Concentration 1)	1657	2041	1188	602	249

  

SALMONELLA/MAMMALIAN-MICROSOME MUTAGENICITY TEST EXPERIMENTS WITHOUT MICROSOMAL ACTIVATION NUMBER OF BACK-MUTANT COLONIES PER PLATE (ARITHMETIC MEAN)

Strain	TA 98	TA 100	TA 102	TA 1535	TA 1537
Control	28	131	328	18	7
20 µg/0.1 ml	28	138	291	14	8
78 µg/0.1 ml	26	143	310	18	11
313 µg/0.1 ml	29	165	324	15	8
1250 µg/0.1 ml	27	131	298	14	8
5000 µg/0.1 ml	16	52	140	10	7
Positive control (Vehicle)	26	129	305	16	9
Positive control (Concentration 1)	572	775	1008	582	66
Positive control (Concentration 2)	856	1275	1368	813	982

 

 SALMONELLA/MAMMALIAN-MICROSOME MUTAGENICITY TEST EXPERIMENTS WITH MICROSOMAL ACTIVATION NUMBER OF BACK-MUTANT COLONIES PER PLATE (ARITHMETIC MEAN)

Strain	TA 98	TA 100	TA 102	TA 1535	TA 1537
Control	52	141	326	17	19
20 µg/0.1 ml	46	132	309	17	24
78 µg/0.1 ml	60	126	353	13	21
313 µg/0.1 ml	70	123	350	11	25
1250 µg/0.1 ml	55	136	486	12	17
5000 µg/0.1 ml	24	67	133	4	5
Positive control (Vehicle)	50	119	278	22	14
Positive control (Concentration 1)	1853	1600	1296	614	106

 

Applicant's summary and conclusion

Conclusions:

No evidence of the induction of point mutations by FAT 20004/G or by the metabolites of the substance formed as a result of microsomal activation was detectable in the strains of S. typhimurium used in these experiments.

Executive summary:

FAT 20004/G was tested for mutagenic effects on histidine-auxotrophic mutants of Salmonella typhimurium. This study was conducted according to method equivalent or similar to OECD test guideline 471. The investigations were performed on strains TA 98, TA 100, TA 102, TA 1535 and TA 1537 with the following concentrations of the trial substance without and with microsomal activation: 20, 78, 313, 1250 and 5000 µg/0.1 ml. In order to confirm the results, the experiments were repeated. These tests permit the detection of point mutations in bacteria induced by chemical substances. Any mutagenic effects of the substances are demonstrable on comparison of the number of bacteria in the treated and control cultures that have undergone back-mutation to histidine-prototrophism. To ensure that mutagenic effects of metabolites of the test substances formed in mammals would also be detected, experiments were performed in which the cultures were additionally treated with an activation mixture (rat liver microsomes and co-factors). In the experiments performed without and with microsomal activation, treatment of the cultures with the various concentrations of FAT 20004/G did not increase the incidence of back-mutant colonies by comparison with the negative control. Owing to a growth-inhibiting effect of the substance a reduction in the colony count was observed at the highest concentration. No evidence of the induction of point mutations by FAT 20004/G or by the metabolites of the substance formed as a result of microsomal activation was detectable in the strains of S. typhimurium used in these experiments.