1,3,6-Naphthalenetrisulfonic acid, 7-[2-[2-[(aminocarbonyl)amino]-4-[[4-chloro-6-[[4-[[2-(sulfooxy)ethyl]sulfonyl]phenyl]amino]-1,3,5-triazin-2-yl]amino]phenyl]diazenyl]-, sodium salt

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus

Type of information:

experimental study

Adequacy of study:

key study

Study period:

10 April 2002 to 30 April 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2003

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EU Method B.12 (Mutagenicity - In Vivo Mammalian Erythrocyte Micronucleus Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.5395 (In Vivo Mammalian Cytogenetics Tests: Erythrocyte Micronucleus Assay)

Deviations:

no

GLP compliance:

yes

Type of assay:

micronucleus assay

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

454-280-8

EC Name:

-

Cas Number:

184889-95-0

Molecular formula:

Hill formula: C28H19ClN9Na3O12S4 CAS formula: C28H22ClN9O12S4.3Na

IUPAC Name:

Trisodium 7-((2-((aminocarbonylamino)-4-(4-chloro-6-((3-ethe nylsulfonyl)phenyl)amino)-1,3,5-triazine-2-yl)amino)phenyl)a zo-1,3,6-naphthalenetrisulfonate

Test material form:

solid: particulate/powder

Details on test material:

Test item: Structural Analogue 01

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

Species of animals: rat
Strain of animals: Hsd:Sprague Dawley
Origin (supplier) of animals: Harlan Winkelmann GmbH Gartenstrasse 27, 33178 Borchen
Animal identification: fur marking with KMn04 and cage numbering
Body weight at start of study: male animals
mean = 189.8 g (= 100 %)
min = 178 g (-6.2%)
max = 202 g (+6.4%)
n = 15
female animals
mean = 152.7 g (= 100 %)
min = 148 g (-3.1%)
max = 162 g (+6.1%)
n = 15
Age at start of study: male animals approximately 6 weeks, female animals approximately 6 weeks
Randomisation procedure: Randomisation schemes 2003.0198 and 2003.0199
Animal maintenance: five animals per cage in transparent macrolon cages (type IV) on soft wood granulate in an air-conditioned room (room number 011)
Room temperature: 22 °C ± 3 °C (except short lasting deviations due to disturbances of air condition)
Relative humidity: 50 % ± 20 % (except short lasting deviations due to disturbances of air condition)
Lighting times: 12 hours light / dark cycle
Acclimatisation: 5 days under study conditions
Food: rat/mice diet ssniff® R/M-H (V 1534), ad libitum ssniff® GmbH, Postbox 2039, 59480 Soest
Water:tap water in plastic bottles, ad libitum

Administration / exposure

Route of administration:

oral: unspecified

Vehicle:

- Vehicle(s)/solvent(s) used:Deionised water
- Justification for choice of solvent/vehicle: Historical use within the laboratory.
- Concentration of test material in vehicle: 200 mg/ml

Details on exposure:

Frequency of administrations: two doses separated by an interval of 24 hours (except positive control with only one dose).

Duration of treatment / exposure:

24 hours

Frequency of treatment:

Two doses

Post exposure period:

No post exposure period

Doses / concentrations

Dose / conc.:

2 000 mg/kg bw/day (actual dose received)

No. of animals per sex per dose:

Group Dose Concentration Volume No. of animals Animal No. Killing time
(mg/kg bwt.) (mg/ml) (ml/kg bwt.) and sex (hours p.a.)
1 0 0 10 5 males 1 – 5 24
5 females 6 -10
2 2000 200 10 5 males 11 – 15 24
5 females 16 – 20
3* 40 4.0 10 5 males 21 – 25 24
5 females 26 – 30

* = positive control: Endoxan® (batch no. 9M642A) containing cyclophosphamide, dissolved in distilled water
Hours p.a. = hours after administration

Control animals:

yes, concurrent vehicle

Positive control(s):

Name: cyclophosphamide
Synonyms: Endoxan®
CAS-Register number: 6055-19-2
Batch number: 2K645B
Certificate of analysis: certified by the supplier, Quality Control, Dr. Hofmann dated 10-Dec-2002

Examinations

Tissues and cell types examined:

chromosomal damage (clastogenicity) in a rat bone marrow

Details of tissue and slide preparation:

PREPARATION AND STAINING

Extraction of the bone marrow
Animals were killed by carbon dioxide asphyxiation 24 hours after second dosing. One femoral bone was removed and the bone freed of muscle tissue. The proximal end of the femoral bone was opened, the bone marrow flushed into a centrifuge tube containing about 3 ml of fetal bovine serum and a suspension was prepared. The mixture was then centrifuged for 5 minutes at approx. 1200 rpm, after which almost all the supernatant was discarded. One drop of the thoroughly mixed sediment was smeared onto a cleaned slide, identified by project code and animal number and air-dried for about 12 hours.

Subsequently the slides were stained as follows:
Staining procedure
5 minutes in methanol
5 minutes in May-Grunwald's solution
brief rinsing twice in distilled water
10 minutes staining in 1 part Giemsa solution to 6 parts buffer solution, pH 7.2 (Weise)
rinsing in distilled water drying
coating with Entellan®

Evaluation criteria:

SCORING AND EVALUATION OF DATA

Scoring
2000 polychromatic erythrocytes were counted for each animal. The number of cells with micro-nuclei was recorded, not the number of individual micronuclei. In addition, the ratio of polychro-matic erythrocytes to 200 normochromatic erythrocytes was determined. Main parameter for the statistical analysis, i.e. validity assessment of the study and mutagenicity of the test substance, was the proportion of polychromatic erythrocytes with micronuclei out of the 2000 counted erythrocytes. All bone marrow smears for evaluation were coded to ensure that the group from which they were taken remained unknown to the investigator.

Criteria for assay validity
An one-sided Wilcoxon-Test was performed to check the validity of the study. The study was considered as valid if the proportion of polychromatic erythrocytes with micronuclei in the positive control was significantly higher than in the negative control (p<0.05).

Data analysis
Assuming the study is valid based on a monotone-dose-relationship, one-sided Wilcoxon tests were performed initially comparing control values with those of the highest dose group. A significance level of 5% is adopted for all tests.

CRITERIA FOR A POSITIVE RESPONSE
Both biological and statistical significances were considered together for evaluation purposes.
A substance is considered as positive if there is a significant or dose-related increase in the number of micronucleated polychromatic erythrocytes compared with the concurrent negative control group. A test substance producing no significant or dose-related increase in the number of micronucleated polychromatic erythrocytes is considered as non-clastogenic in this system.

Statistics:

As detailed above under "Evaluation Criteria".

Results and discussion

Test results

Sex:

male/female

Genotoxicity:

negative

Toxicity:

no effects

Vehicle controls validity:

valid

Positive controls validity:

valid

Additional information on results:

Rats were treated twice at an interval of 24 hours with 2000 mg/kg body weight to study the induction of micronuclei in bone marrow cells.

All animals survived after treatment. No signs of toxicity were observed in the main study.

The dissection of the animals revealed no test substance related macroscopic findings.
The bone marrow smears were examined for the occurrence of micronuclei in red blood cells.

A very slight increase of micronucleated polychromatic erythrocytes (mean value) was observed in the animals treated with 2000 mg/kg of the test compound. However, the incidence of micronucleated polychromatic erythrocytes in this dose group was within the historical range of the negative control groups (mean of micronucleated polychromatic erythrocytes per 2000 cells: 1.7-4.9). Moreover, the increase was not statistically significant. It was therefore considered as incidental finding without biological relevance.

The ratio of polychromatic erythrocytes to total erythrocytes remained essentially unaffected by the test compound and differed less than 20% from the control values.

Cyclophosphamide (Endoxan®) induced a marked and statistically significant increase in the number of polychromatic erythrocytes with micronuclei, thus indicating the sensitivity of the test system.

Any other information on results incl. tables

SUMMARY TABLES AND STATISTICS

 

Sex	Dose mg/kg b.w.	Killing time	Number of animals	Poly / animal counted	Poly/Ery   Mean	Poly/Ery SD Mean	Poly with MN   Mean	Poly with MN [%] Mean	Poly with MN SD Mean
Male	0 – Control	24 h	5	2000	0.48	0.08	2.4	0.12	0.08
Male	2000	24 h	5	2000	0.48	0.04	2.6	0.18	0.04
Male	40 – Endoxan	24 h	5	2000	0.43	0.05	28.2*	1.41	0.70
Female	0 – Control	24 h	5	2000	0.50	0.04	2.4	0.12	0.08
Female	2000	24 h	5	2000	0.47	0.04	3.4	0.17	0.10
Female	40 – Endoxan	24 h	5	2000	0.40	0.05	18.8*	0.94	0.24

 

Sex	Dose mg/kg b.w.	Killing time	Number of animals	Poly / animal counted	Poly/Ery   Mean	Poly/Ery SD Mean	Poly with MN   Mean	Poly with MN [%] Mean	Poly with MN SD Mean	Mut. I.
Pooled	0 – Control	24 h	10	2000	0.49	0.06	2.40	0.1	0.07	1.0
Pooled	2000	24 h	10	2000	0.48	0.04	3.50	0.2	0.07	1.5
Pooled	40 – Endoxan	24 h	10	2000	0.42	0.05	23.5*	1.2	0.55	9.8

 

Mut. I. = Mutagenic Index

Control = Vehicle (deionised water)

* = Significantly different from control (p < 0.05)

 

A cross comparison of individual data and pooled data may show discrepancies since the values are rounded.

Applicant's summary and conclusion

Conclusions:

The results lead to the conclusion that the test item did not cause a substantial increase in micronucleated polychromatic erythrocytes and is not clastogenic in the micronucleus test in vivo under the conditions described in this report.

Executive summary:

The test compound was suspended in deionised water and was given twice at an interval of 24 hours as oral doses of 2000 mg per kg body weight to male and female rats (Hsd:Sprague Dawley), based on the results of a previous dose range finding assay. Endoxan® was used as positive control substance and was administered once orally at a dose of 40 mg per kg body weight.

The number of polychromatic erythrocytes containing micronuclei in all dose groups was not significantly increased compared with the control. The ratio of polychromatic erythrocytes to total erythrocytes in both male and female animals remained unaffected by the treatment with the test item and differed less than 20% from the control value.

Endoxan® induced a marked statistically significant increase in the number of polychromatic cells with micronuclei, indicating the sensitivity of the test system. The ratio of polychromatic erythrocytes to total erythrocytes was not changed to a significant extent.

Under the conditions of the present study the results indicate that the test item is not clastogenic in the micronucleus test in vivo.