1-phenylazo-2-naphthol

Genetic toxicity: in vivo

Administrative data

Endpoint:

genetic toxicity in vivo

Remarks:

Type of genotoxicity: genome mutation

Type of information:

experimental study

Adequacy of study:

key study

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:

Repeated-dose liver and gastrointestinal tract micronucleus assays with CI Solvent Yellow 14 (Sudan I) using young adult rats

Author:

Shoji Matsumura, Naohiro Ikeda, Shuichi Hamada, Wakako Ohyama, Yumi Wako, Kazufumi Kawasako, Toshio Kasamatsu, Naohiro Nishiyama

Year:

2015

Bibliographic source:

Mutation Research 780-781 (2015) 76–80

Materials and methods

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

Bone marrow MN micronucleus (MN) assay was performed to determine the mutagenic nature of Solvent yellow 14

GLP compliance:

not specified

Type of assay:

other: Bone marrow MN micronucleus (MN) assay

Test material

Test material information

Constituent 1

Reference substance name:

1-phenylazo-2-naphthol

EC Number:

212-668-2

EC Name:

1-phenylazo-2-naphthol

Cas Number:

842-07-9

Molecular formula:

C16H12N2O

IUPAC Name:

1-[(E)-2-phenyldiazen-1-yl]naphthalen-2-ol

Test material form:

solid: crystalline

Details on test material:

- Name of test material (as cited in study report): Solvent yellow 14
- Molecular formula (if other than submission substance): C16H12N2O
- Molecular weight (if other than submission substance): 248.28
- InChl (if other than submission substance):1S/C16H12N2O/c19-15-11-10-12-6-4-5-9-14(12)16(15)18-17-13-7-2-1-3-8-13/h1-11,19H/b18-17+
- Substance type: Organic
- Physical state: Solid
- Analytical purity: >95%
- Impurities (identity and concentrations): No data

Specific details on test material used for the study:

- Name of test material: Solvent yellow 14
- Molecular formula: C16H12N2O
- Molecular weight: 248.284 g/mol
- Substance type: Organic
- Physical state: Solid
- Purity: >95%
- Impurities (identity and concentrations): No data available

Test animals

Species:

rat

Strain:

Crj: CD(SD)

Details on species / strain selection:

No data

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Japan Inc. (Yokohama,Japan)
- Age at study initiation: 6 weeks old
- Weight at study initiation: No data available
- Assigned to test groups randomly: No data available
- Fasting period before study: No data available
- Housing: The animals were housed in an air-conditioned room
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: No data available

ENVIRONMENTAL CONDITIONS
- Temperature (°C): No data available
- Humidity (%): No data available
- Air changes (per hr): No data available
- Photoperiod (hrs dark / hrs light): 12 h light/dark cycle

IN-LIFE DATES: From: To: No data available

Administration / exposure

Route of administration:

oral: unspecified

Vehicle:

- Vehicle(s)/solvent(s) used: yes- methyl cellulose
- Justification for choice of solvent/vehicle: No data available
- Concentration of test material in vehicle: 0, 150, 300, and 600 mg/kg/day
- Amount of vehicle (if gavage or dermal): No data available
- Type and concentration of dispersant aid (if powder): No data available
- Lot/batch no. (if required): No data available
- Purity: No data available

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: Sudan I was suspended in 0.5% (w/v) Methyl Cellulose Solution (Wako Pure Chemical Industries, Ltd., Osaka, Japan) each day before dosing to guve a dose range of 0, 150, 300 or 600 mg/Kg/day

DIET PREPARATION
- Rate of preparation of diet (frequency): No data available
- Mixing appropriate amounts with (Type of food): No data available
- Storage temperature of food: No data available

Duration of treatment / exposure:

14 days

Frequency of treatment:

Daily

Post exposure period:

No data available

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 150, 300, and 600 mg/kg/day

No. of animals per sex per dose:

Total: 20
0 mg/Kg/day: 5 male rats
150 mg/Kg/day: 5 male rats
300 mg/Kg/day: 5 male rats
600 mg/Kg/day: 5 male rats

Control animals:

yes, concurrent vehicle

Positive control(s):

No data available

Examinations

Tissues and cell types examined:

Micronucleated Bone marrow cells

Details of tissue and slide preparation:

CRITERIA FOR DOSE SELECTION: Dose range finding study was conducted, The animals were dosed once daily for 7 days with 75, 150, 300, and 600 mg/kg/day of Sudan I and were monitored for clinical signs and body weight changes. A decrease in body weight was observed in the 600 mg/kg/day group compared with the vehicle control group, but no lethality or decrease in motor activity was observed. Based on these observations, the highest dose was set as 600 mg/kg/day and set the lower doses with the common ratio of two (300 and 150 mg/kg/day).

TREATMENT AND SAMPLING TIMES ( in addition to information in specific fields): No data available

DETAILS OF SLIDE PREPARATION: smear preparations were made from the bone marroe cells and then stained with an AO solution and covered with a cover slip.

METHOD OF ANALYSIS: The specimens were observed under a fluorescent microscope with B-excitation (Blue light excitation), and the number of micronucleated immature erythrocytes (MNIMEs) per 2000 immature erythrocytes (IMEs) was counted for each animal.

OTHER: No data available

Evaluation criteria:

Micronucleated Bone marrow cells were observed

Statistics:

Differences in the incidences of MNHEPs between the test and the vehicle control groups were analyzed using the conditional binomial test reported by Kastenbaum and Bowman at the upper-tailed significance levels of 5% and 1%. The exception was that a Chi-squared test
was performed to analyze differences in the incidences of micronucleated immature erythrocytes (MNIMEs) between the test groups and the vehicle-treated control group.

The data were also statistically analyzed by a multiple comparison test according to the requirements of the organizing committee. Specifically, the homogeneity of the variance was examined using Bartlett’s test. When a homogeneous variance was demonstrated, one-way analysis of variance was applied. In cases of heterogeneous variance, the Kruskal–Wallis test was applied. When a statistically significant difference was demonstrated between groups, the difference was assessed by Dunnett’s test or a Dunnett-type multiple comparison test.

Results and discussion

Test results

Sex:

male

Genotoxicity:

positive

Toxicity:

not specified

Vehicle controls validity:

valid

Negative controls validity:

not specified

Positive controls validity:

not specified

Additional information on results:

RESULTS OF RANGE-FINDING STUDY
- Dose range: 75, 150, 300, and 600 mg/kg/day
- Solubility: No data available
- Clinical signs of toxicity in test animals: A decrease in body weight was observed in the 600 mg/Kg/bw dose level - Evidence of cytotoxicity in tissue analyzed: No data available
- Rationale for exposure: No data available
- Harvest times: No data available
- High dose with and without activation: No data available
- Other:No data available

RESULTS OF DEFINITIVE STUDY
- Types of structural aberrations for significant dose levels (for Cytogenetic or SCE assay): No data available
- Induction of micronuclei (for Micronucleus assay): No data available
- Ratio of PCE/NCE (for Micronucleus assay): No data available
- Appropriateness of dose levels and route: No data available
- Statistical evaluation: No data available

Any other information on results incl. tables

Results of the Bone marrow MN assay with Sudan:

 

Sudan I (mg/kg/day)	No. of animals	MNIMEs (%) individual data (mean±SD)
0	5	0.60, 0.65, 0.75, 0.25, 0.50 (0.55±0.19)
150	5	0.75, 1.25, 1.75, 1.10, 1.25 (1.22±0.35*)
300	5	0.65, 1.30, 2.00, 3.25, 1.65 (1.77±0.96*)
600	5	1.80, 2.40, 3.25, 1.75, 2.70 (2.38±0.63*)

* p < 0.01, Chi-squared test.

Applicant's summary and conclusion

Conclusions:

There was statistically significant increase in the incidences of MNIMEs observed with the repeated administration of 1-phenylazo-2-naphthol (Sudan I). Therefore in vivo genetic toxicity of 1-phenylazo-2-naphthol (Sudan I) is positive.

Executive summary:

The in vivo Geno toxicity of 1-phenylazo-2-naphthol (Sudan I) was examined using repeated-doseBone marrowmicronucleus (MN) assays in young adult maleCrl: CD (SD)rats.

They performed a dose range finding study. The animals were dosed once daily for 7 days with 75, 150, 300, and 600 mg/kg/day of Sudan I and were monitored for clinical signs and body weight changes. A decrease in body weight was observed in the 600 mg/kg/day group compared with the vehicle control group, but no lethality or decrease in motor activity was observed. Based on these observations, we determined the highest dose as 600 mg/kg/day and set the lower doses with the common ratio of two (300 and 150 mg/kg/day). BM cells were collected from the femurs. Immediately prior to microscopic observation, smear preparations were made with each sample and then stained with an AO solution and covered with a cover slip. The specimens were observed under a fluorescent microscope with B-excitation (Blue light excitation), and the number of micronucleated immature erythrocytes (MNIMEs) per 2000 immature erythrocytes (IMEs) was counted for each animal.

There was statistically significant increase in the incidences of MNIMEs observed with the repeated administration of Sudan I. Therefore in vivo genetic toxicity of 1-phenylazo-2-naphthol (Sudan I) is positive.