Azelaic acid

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:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Well documented study, comparable to guideline and acceptable for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1982

Report date:

1982

Materials and methods

Test guideline

Qualifier:

equivalent or similar 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:

Azelaic acid

EC Number:

204-669-1

EC Name:

Azelaic acid

Cas Number:

123-99-9

Molecular formula:

C9H16O4

IUPAC Name:

azelaic acid

Details on test material:

- Name of test material (as cited in study report): ZK 62.498 (azelaic acid)
- Physical state: solid
- Lot/batch No.: ZK 62.498
- Stability under test conditions: Suspensions of the test material between 1 and 125 mg/ml are stable for 72 hrs.
- Storage condition of test material: room temperature

Method

Target gene:

HIS

Species / strain

Species / strain 1

Species / strain / cell type:

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

Species / strain 2

Species / strain / cell type:

S. typhimurium TA 1538

Metabolic activation:

with and without

Metabolic activation system:

S9-Mix

Test concentrations with justification for top dose:

0.01 to 10 mg per plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: [vehicle: NaCl 0.9 g, Myrj 53 0.085 g ad 100 ml bidistilled water]
- Justification for choice of solvent/vehicle: This vehicle was a suitable vehicle for the Ames test

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

yes

Positive controls:

yes

Positive control substance:

2-nitrofluorene

benzo(a)pyrene

cyclophosphamide

other: anthracen-2-amine, 1-methyl-3-nitro-1-nitrosoguanidine

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)

The mutagenicity tests were carried out by adding 0.1 ml of the bacteriasuspension, 0.1 ml of the test material and 0.5 ml of 0.1M phosphate buffer pH 7.4 or S 9 mix to a sterile tube containing 2 ml of molten soft agar with minimal amounts of histidine and biotine. The contents of the tubes were mixed thoroughly and poured onto histidine free minimal medium plates (Vogel-Bonner agar). All plates were prepared in triplicate within about 1 h, allowed to solidify and incubated at 37°c for approx. 72 hours.

Controls
0.1 ml of the solvents were plated as negative controls. For checking the activity of the metabolizing system and the mutability of the bacteria three reference mutagens were tested for each strain. Their mutagenic effect occurred either directly (2-NF, MNNG) or after metabolic activation (2-AA, BP, CP).

Sterility controls were performed additionally.
Aliquots of a 10-6 dilution of the overnight culture were spread onto complete agar to measure the viability and cell density of each culture.

Evaluation criteria:

The plates were scored for the number of mutant colonies with an automated colony counter (Biotran II, Model C 111, New Brunswick
Scientific Co., Edison, N.J.). The arithmetic means of the number of mutant colonies of the 3 parallel plates in the negative control group were compared with those of the compound groups. A positive response was considered if at least 5 mg/plate or up to a toxic dose had been tested (or the compound formed precipitates in the agar) and if the number of induced revertants compared to the spontaneous was higher than 2-fold (TA 1535, 100, 1538, 98) or 3-fold (TA 1537). Also a dose dependent increase in the number of revertants was considered to indicate a mutagenic effect.
A toxic effect of the substance on the background lawn of nonrevertant bacteria and precipitates in the agar were examined
stereomicroscopically.

Statistics:

N/A

Results and discussion

Test results

Test results 1

Species / strain:

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

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

Growth inhibition of the background lawn could be observed at 10 mg/plate (TA 1535, TA 98)and at 5 and 10 mg/plate with TA 1537.

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 1538

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

Growth inhibition of the background lawn could be observed at 10 mg/plate (TA 1535, TA 98)and at 5 and 10 mg/plate with TA 1537.

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

The highest observed increase of induced revertants compared to the spontaneous number in the control in any of the experiments was 1.76 and thus lower than the required 2-fold increase for a positive result.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.