Disodium 2-(2,4,5,7-tetraiodo-6-oxido-3-oxoxanthen-9-yl)benzoate

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian cell study: DNA damage and/or repair

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 reviwed journal

Data source

Reference

Reference Type:

publication

Title:

Testing of 24 Food, Drug, Cosmetic, and Fabric Dyes in the In Vitro and the In Vivo/ In Vitro Rat Hepatocyte Primary Culture/ DNA Repair Assays

Author:

Douglas Kornbrust and Thomas Barfknecht

Year:

1985

Bibliographic source:

Environmental Mutagenesis 7:101-120 (1985)

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: in vivo rat hepatocyte primary culture/DNA repair (HPC/DR) assay

Principles of method if other than guideline:

The test chemical was tested for the in vivo rat hepatocyte primary culture/DNA repair (HPC/DR) assay.

GLP compliance:

not specified

Type of assay:

other: In Vivo/ In Vitro Rat Hepatocyte Primary Culture/ DNA Repair Assays

Test material

Test material information

Constituent 1

Reference substance name:

Disodium 2-(2,4,5,7-tetraiodo-6-oxido-3-oxoxanthen-9-yl)benzoate

EC Number:

240-474-8

EC Name:

Disodium 2-(2,4,5,7-tetraiodo-6-oxido-3-oxoxanthen-9-yl)benzoate

Cas Number:

16423-68-0

Molecular formula:

C20H8I4O5.2Na

IUPAC Name:

disodium 2-(2,4,5,7-tetraiodo-6-oxido-3-oxoxanthen-9-yl)benzoate

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material (as cited in study report): Erythrosine
- Molecular formula (if other than submission substance): C20-H6-I4-Na2-O5
- Molecular weight (if other than submission substance): 879.86
- InChl Key (if other than submission substance): RAGZEDHHTPQLAI-UHFFFAOYSA-L
-Substance type- Organic
- Physical state: Solid (powder)
-Purity: 93 % dye
- Impurities (identity and concentrations): 7%

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories, Inc., Kingston, NY
- Age at study initiation: No data available
- Weight at study initiation: 200-300 g
- Assigned to test groups randomly: [no/yes, under following basis: ] No data available
- Fasting period before study: No data available
- Housing: The animals were housed in humidity- and temperature-controlled rooms.

- Diet (e.g. ad libitum): Diet (ad libitum)
- Water (e.g. ad libitum): Water (ad libitum)
- Acclimation period: No data available

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

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

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

- Vehicle(s)/solvent(s) used: aqueous solutions or corn oil suspensions (for the non-water-soluble dyes)

Duration of treatment / exposure:

2 hour and 15 hour time point

Frequency of treatment:

Onces daily

Post exposure period:

No data available

Doses / concentrations

Remarks:

Doses / Concentrations:
200 mg/kg
Basis:
no data

No. of animals per sex per dose:

six to eight rats

Control animals:

yes, concurrent vehicle

Positive control(s):

o-aminoazotoluene

Examinations

Tissues and cell types examined:

Rat hepatocytes

Details of tissue and slide preparation:

OTHER: Six to eight rats were perfused on a given day (ie, experiment), including one control (ie, usually corn oil-treated) from which hepatocytes were obtained for in vitro assays. One or more known positive chemicals (usually SY3) were tested .DNA repair was quantified by the autoradiographic determination of incorporated [3H]-thymidine, similar to the method of Williams [1977] and Bermudez et al [1979], as detailed in Kornbrust and Barfknecht [1984a,b]. Net nuclear grains (NNG) were determined by counting the number of grains in each nuclei and subtracting the average number of grains present in three equal-size adjacent cytoplasmic areas. A strict procedure for random selection of cells was used [Mirsalis and Butterworth,1980]. The average NNG for 60 cells (±SD) as well as the percentage of cells with 25 NNG was determined for the test chemical. single dose was given that was equal to approximately 50% of the single dose LD50 (derived from reference toxicity data) or 500 mg/k body weight, whichever was smaller.
 

Evaluation criteria:

Average net nuclear grain counts of 5 or greater were assumed to constitute a positive response, since these differed from the control net nuclear counts by greater than 2 SD. Net nuclear grain counts below zero were considered negative responses.

For those dyes that produced responses between zero and 5 average net nuclear grains, it was generally not possible to demonstrate a statistically significant difference from the control value within a given experiment. Therefore, these responses were judged to be equivocal, unless, in addition to an average net nuclear grain count between zero and 5, at least 25% of the cells examined contained ≥ 5 net nuclear grains, in which case the response was considered weakly positive.

Concentrations of the dyes that produced approximately 90% or greater detachment of the hepatocytes from the coverslips (as assessed visually by comparing to control slides) were assumed to be toxic and were not counted.

Statistics:

Average net nuclear grains was reported as Mean ± standard deviation

Results and discussion

Test results

Sex:

male

Genotoxicity:

negative

Toxicity:

no effects

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: non mutagenic

Additional information on results:

RESULTS OF RANGE-FINDING STUDY
- Dose range:
- Solubility:
- Clinical signs of toxicity in test animals:
- Evidence of cytotoxicity in tissue analysed:
- Rationale for exposure:
- Harvest times:
- High dose with and without activation:
- Other:

RESULTS OF DEFINITIVE STUDY : The test chemical was negative i.e gave no induction of DNA repair when tested at 200 mg/plate in Wistar rats
- Types of structural aberrations for significant dose levels (for Cytogenetic or SCE assay):
- Induction of micronuclei (for Micronucleus assay):
- Ratio of PCE/NCE (for Micronucleus assay):
- Appropriateness of dose levels and route:
- Statistical evaluation:

Any other information on results incl. tables

Responses Produced by Various Dyes in the In Vivo/In Vitro HPC/DR Assay

Dye	Dose	Time PTP^a (hr)	Avg. NNG^b	Percent cells<5 NNG	Res- ponse
Acid red 51	200	2 15	-1.0 (± 3.3) -1.1 (± 3.1)	5 5	N
^aTime that dye was administered prior to start of liver perfusion and isolation of hepatocytes. ^bAverage net nuclear grains (as defined in the Methods section); mean + standard deviation from 60 cells. ^CPercent of cells with > S net nuclear grains. ^dP. positive; WP, weak positive; E, equivocal; N, negative (as per the criteria defined in the Methods section).

Applicant's summary and conclusion

Conclusions:

The test chemical was negative i.e gave no induction of DNA repair when tested at 200 mg/plate in Wistar rats.

Executive summary:

In vivo HPC/DR genetic toxicity in vivo assay was performed for the test chemical by study on hepatocytes isolated from rat. Six to eight rats were perfused on a given day (ie, experiment), including one control (ie, usually corn oil-treated) from which hepatocytes were obtained for in vivo assays. One or more known positive chemicals (usually SY3) were tested .DNA repair was quantified by the autoradiographic determination of incorporated [3H]-thymidine, similar to the method of Williams [1977] and Bermudez et al [1979], as detailed in Kornbrust and Barfknecht [1984a,b]. Net nuclear grains (NNG) were determined by counting the number of grains in each nuclei and subtracting the average number of grains present in three equal-size adjacent cytoplasmic areas. A strict procedure for random selection of cells was used [Mirsalis and Butterworth,1980]. The average NNG for 60 cells (±SD) as well as the percentage of cells with 25 NNG was determined for the test chemical. single dose was given that was equal to approximately. Average net nuclear grain counts of 5 or greater were assumed to constitute a positive response, since these differed from the control net nuclear counts by greater than 2 SD. The NNG count for the test chemical was less than 5 and the test chemical was negative i.e gave no induction of DNA repair when tested at 200 mg/plate in Wistar rats.