7-benzamido-4-hydroxynaphthalene-2-sulphonic acid

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data is from peer reviewed publication

Data source

Reference

Reference Type:

publication

Title:

Salmonella Mutagenicity Tests: III. Results from the Testing of 255 Chemicals

Author:

Errol Zeiger, Beth Anderson, Steve Haworth, Timothy Lawlor, Kristien Mortelmans, and William Speck

Year:

1987

Bibliographic source:

Environmental Mutagenesis Volume 9, Supplement 9: 1-110, 1987

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Principles of method if other than guideline:

Bacterial reverse mutation assay was performed to evaluate the mutagenic nature of the test compound 1(2H)Phthalazinone

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

phthalazin-1(2H)-one

Cas Number:

119-39-1

Molecular formula:

C8H6N2O

IUPAC Name:

phthalazin-1(2H)-one

Details on test material:

- Name of test material: 1(2H)Phthalazinone
- IUPAC name: phthalazin-1(2H)-one
- Molecular formula: C8H6N2O
- Molecular weight: 146.1484 g/mol
- Substance type: Organic
- Physical state: No data
- Purity: No data
- Impurities (identity and concentrations): No data

Specific details on test material used for the study:

- Name of test material: 1(2H)Phthalazinone
- IUPAC name: phthalazin-1(2H)-one
- Molecular formula: C8H6N2O
- Molecular weight: 146.1484 g/mol
- Substance type: Organic
- Physical state: No data
- Purity: No data
- Impurities (identity and concentrations): No data

Method

Target gene:

Histidine

Species / strain

Species / strain / cell type:

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

Details on mammalian cell type (if applicable):

Not applicable

Additional strain / cell type characteristics:

not specified

Cytokinesis block (if used):

No data

Metabolic activation:

with and without

Metabolic activation system:

The S-9 fractions of Aroclor 1254-induced, male Sprague-Dawley rat and male Syrian hamster livers were prepared

Test concentrations with justification for top dose:

0, 100, 333, 1000, 3333 or 10000 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: The chemical was soluble and stable in DMSO

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

yes

Positive controls:

yes

Positive control substance:

9-aminoacridine

sodium azide

other: 2-Aminoanthracene (All strains; With S9)

Details on test system and experimental conditions:

METHOD OF APPLICATION: preincubation

DURATION
- Preincubation period: 20 mins
- Exposure duration: 48 hrs
- Expression time (cells in growth medium): 48 hrs
- Selection time (if incubation with a selection agent): No data available
- Fixation time (start of exposure up to fixation or harvest of cells): No data available

SELECTION AGENT (mutation assays): No data available
SPINDLE INHIBITOR (cytogenetic assays): No data available
STAIN (for cytogenetic assays): No data available

NUMBER OF REPLICATIONS: Triplicate

NUMBER OF CELLS EVALUATED: No data available

DETERMINATION OF CYTOTOXICITY
- Method: mitotic index; cloning efficiency; relative total growth; other: No data available

OTHER EXAMINATIONS:
- Determination of polyploidy: No data available
- Determination of endoreplication: No data available
- Other:

OTHER: No data available

Rationale for test conditions:

No data

Evaluation criteria:

An individual trial was judged mutagenic (+) if a dose-related increase over the corresponding solvent control was seen, and it was judged weakly mutagenic C+W) if a low-level dose response was seen. A trial was considered questionable (?) if a dose-related increase was judged insufficiently high to justify a call of "+W," if only a single dose was elevated over the control, or if a non-dose-related increase was seen.

The chemical was judged to be mutagenic (+), or weakly mutagenic (+W), if it produced a reproducible, dose-related increase in his+ revertants over the corresponding solvent controls in replicate trials.

It chemical was considered to be questionable (?) if a reproducible increase of his+ revertants did not meet the criteria for either a " + " or " + W," or if only single doses produced an increase in his+ revertants in repeat trials.

Statistics:

Mean and Standard error of mean (SEM)

Results and discussion

Test results

Species / strain:

S. typhimurium, other: TA98, TA100, TA1535, and TA1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Effects of pH: No data available
- Effects of osmolality: No data available
- Evaporation from medium: No data available
- Water solubility: No data available
- Precipitation: No data available
- Other confounding effects: No data available

RANGE-FINDING/SCREENING STUDIES: The chemical was tested initially in a toxicity assay to determine the appropriate dose range. The toxicity assay was performed by using TA100 or the system developed by Waleh et al. Toxic concentrations were those at which a decrease in the number of his+ colonies was seen or at which there was a clearing in the density of the background lawn

COMPARISON WITH HISTORICAL CONTROL DATA: No data available

ADDITIONAL INFORMATION ON CYTOTOXICITY: No data available

Any other information on results incl. tables

Table: Mutagenicity of 1(2H)Phthalazinone

Dose (µg/plate)	TA100
	-S9		10% HLI		10% RLI
	Mean	SEM	Mean	SEM	Mean	SEM
0	123	11.1	130	1.2	120	9.8
100	111	11.6	119	9.4	134	6.7
333	122	12.0	127	3.7	131	6.0
1000	103	3.3	127	3.7	120	1.7
3333	94	8.2	108	6.4	5.2
10000	52	5.2	62	5.6	63	3.7
Positive control	1050	27.4	936	31.0	953	64.5

 

Dose (µg/plate)	TA1535
	-S9		10% HLI		10% RLI
	Mean	SEM	Mean	SEM	Mean	SEM
0	24	2.2	9	1.3	11	1.5
100	26	0.6	9	2.3	8	1.3
333	24	1.2	7	0.9	11	1.7
1000	21	2.9	8	1.3	8	1.5
3333	23	4.2	6	2.3	11	1.2
10000	15	2.2	6	0.9	9	1.0
Positive control	766	44.5	47	5.0	49	2.7

 

Dose (µg/plate)	TA1537
	-S9		10% HLI		10% RLI
	Mean	SEM	Mean	SEM	Mean	SEM
0	3	0.3	8	2.7	5	3.0
100	7	2.3	5	1.9	6	2.4
333	7	1.8	4	0.6	7	1.9
1000	5	0.3	6	1.0	7	2.5
3333	5	0.9	7	2.0	5	1.2
10000	3	0.7	6	0.9	4	0.7
Positive control	297	15.6	71	9.6	72	7.2

 

Dose (µg/plate)	TA98
	-S9		10% HLI		10% RLI
	Mean	SEM	Mean	SEM	Mean	SEM
0	14	2.0	24	0.3	14	1.3
100	14	0.6	22	2.6	23	7.2
333	16	3.9	25	0.9	18	3.8
1000	15	1.0	15	3.8	15	0.6
3333	16	2.6	20	1.9	17	3.3
10000	9	1.7	12	0.6	10	0.6
Positive control	1223	56.9	859	12.9	811	26.5

Applicant's summary and conclusion

Conclusions:

1(2H)Phthalazinone did not induce a reproducible, dose-related increase in his+ revertants over the corresponding solvent in the S. typhimurium tester strains TA1535, TA1537, TA98 and TA100 in the presence and absence of S9 metabolic activation system and hence is negative for mutation in vitro.

Executive summary:

Salmonella/microsome test in the absence of exogenous metabolic activation and in the presence of liver S-9 from Aroclor-induced male Sprague-Dawley rats and Syrian hamsters was performed to evaluate the mutagenic nature of the test compound 1(2H)Phthalazinone usingS. typhimuriumtester strains TA1535, TA97, TA98 and TA100. The study was performed as per the preincubation assay and the preincubation time was 20 mins and the plates were incubated for 48 hrs.

 

The test compound was dissolved in DMSO and was used at a dosage level of 0, 100, 333, 1000, 3333 or 10000 µg/plate in the preincubation assay of 48 hrs. Concurrent solvent and positive control chemicals were included in the study.

 

1(2H)Phthalazinone did not induce a reproducible, dose-related increase in his⁺revertants over the corresponding solventin theS. typhimuriumtester strains TA1535, TA1537, TA98 and TA100 in the presence and absence of S9 metabolic activation system and hence is negative for mutation in vitro.