N,N'-dithiodi-o-phenylenedibenzamide

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The test was based on OECD Guideline for Testing of Chemicals: (No. 474 Mammalian Erythrocyte Micronucleus Test, July 1997). This final report and the original raw data were reviewed for adherence to ISO/IEC17025: 2005 General Requirements for the competence of Testing Calibration Laboratories. OECD Guideline for Testing of Chemicals: (No. 474 Mammalian Erythrocyte Micronucleus Test, July 1997); State Environmental Protection Administration: The Guidelines for the Testing of Chemicals ; Ministry of Health, 2005: Technical standards for testing of chemicals.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

transgenic rodent mutagenicity assay

Test material

Test material information

Constituent 1

Reference substance name:

N,N'-dithiodi-o-phenylenedibenzamide

EC Number:

205-201-9

EC Name:

N,N'-dithiodi-o-phenylenedibenzamide

Cas Number:

135-57-9

Molecular formula:

C26H20N2O2S2

IUPAC Name:

N-{2-[(2-benzamidophenyl)disulfanyl]phenyl}benzamide

Test animals

Species:

mouse

Strain:

other: NIH

Sex:

male/female

Details on test animals or test system and environmental conditions:

Animals used: SPF NIH mice were provided by Guangdong Medical Laboratory Animal Center, certified animal No.: SCXK (guangdong) 2008-0002, 5 males and 5 females per group.

Environmental conditions
Test Room: In the Center
Animal house conditions: The test facility was an air-conditioned room with 12h artificial fluorescent light and 12h dark.
Temperature range: 20~25oC.
Humidity range: 40~70%.

Husbandry Practices
Caging: Stainless steel cages were used. Autoclaved clean dry corncob was used as the bedding material. Animals were housed in one group according to sex in cages.
Water bottle: Each cage was supplied with a polypropylene water bottle with a stainless steel nozzle.
Sanitation: Bedding material was changed daily.
Food and water: Standard pellet feed supplied by Guangdong Medical Laboratory Animal Center and ultra-pure filtered sterilized water were provided to the animals freely.
Frequency of providing feed and drinking water: Both drinking water and feed were provided ad libitum.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

material dissovled in distilled water.

Duration of treatment / exposure:

Date of testing: 30 June 2010 - 20 August 2010
108 days

Frequency of treatment:

doses administered at 210, 665, 2100 mg/kg at a volume of 10 ml/kg twice in 24 hours

Doses / concentrations

Doses / concentrations 1

Remarks:

Doses / Concentrations:
210 mg/kg
Basis:
actual ingested

Doses / concentrations 2

Remarks:

Doses / Concentrations:
665 mg/kg
Basis:
actual ingested

Doses / concentrations 3

Remarks:

Doses / Concentrations:
2100 mg/kg
Basis:
actual ingested

No. of animals per sex per dose:

5 males and 5 females

Control animals:

yes

Positive control(s):

Animals of positive control group were given 40mg/kg cyclophosphamide dissolved in normal saline, by intraperitoneal injection and the volume was 10ml/kg. Samples were collected once between 18 and 24 hours following the final treatment for the bone marrow.
Negative control group were given distilled water instead of tested compounds.

Examinations

Tissues and cell types examined:

Bone Marrow Tissue

Results and discussion

Test results

Sex:

male/female

Genotoxicity:

negative

Toxicity:

no effects

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

RESULTS

Toxicity signs: In the dose levels of 210, 665 and 2100 mg/kg, none of the animals displayed abnormalitied during the observation period.

Micronucleated immature erythrocytes: Compared with negative control group, the micronucleus rates and the micronucleus cell frequencies of the test substance group showed no obvious increase (P<0.05). On the other hand, the micronucleus rates and the micronucleus cell frequencies of positive group were higher than negative groups (P<0.01). The detailed data showed in table 1-6.

Proportion of immature erythrocytes among total erythrocytes: The proportion of immature among total erythrocytes of each group had no difference.

Any other information on results incl. tables

Micronucleus rates and Proportion of immature among total erythrocytes

    Table 1

Group (mg/kg)	Number of animal	Number of cells analysed	Number of micronucleated immature erythrocytes	Proportion of micronucleated immature erythrocytes (‰)	Number of micronucleated immature erythrocytes (x±s)	Proportion of immature among total erythrocytes
						P
Negative control group	10	20000	3	0.3	0.3±0.67
210	10	20000	8	0.8	0.8±0.82	0.353
665	10	20000	10	1.0	1.0±1.15	0.684
2100	10	20000	10	1.0	1.0±1.25	0.143
Positive group	10	20000	352	17.6**	35.2±19.50	0.353

           ** Compared with negative control group,P<0.01

 

 

 

 

 

 

 

The detailed data of each animal ( negative control group )

Table 2  

Gender	No. of animal	Number of cells analysed	Number of micronucleated immature erythrocytes	Proportion of micronucleated immature erythrocytes (‰)	Proportion of immature erythrocytes among total erythrocytes (%)
♀	4	2000	0	0	52.0
♀	17	2000	0	0	67.0
♀	18	2000	2	1	56.0
♀	23	2000	0	0	54.8
♀	28	2000	0	0	70.0
♂	1	2000	1	0.5	64.0
♂	19	2000	0	0	69.0
♂	20	2000	0	0	50.0
♂	26	2000	0	0	76.0
♂	28	2000	0	0	64.0

 

 

 

 

 

 

The detailed data of each animal (210mg/kg )

Table 3

Gender	No. of animal（动物号）	Number of cells analysed	Number of micronucleated immature erythrocytes	Proportion of micronucleated immature erythrocytes (‰)	Proportion of immature erythrocytes among total erythrocytes(%)
♀	8	2000	0	0	81.0
♀	14	2000	0	0	57.0
♀	24	2000	0	0	54.0
♀	25	2000	2	1	69.0
♀	26	2000	0	0	51.5
♂	7	2000	2	1	70.0
♂	8	2000	2	1	60.5
♂	18	2000	0	0	71.0
♂	23	2000	1	0.5	71.9
♂	24	2000	1	0.5	69.5

 

 

 

 

 

The detailed data of each animal (665mg/kg )

Table 4

Gender	No. of animal	Number of cells analysed	Number of micronucleated immature erythrocytes	Proportion of micronucleated immature erythrocytes (‰)	Proportion of immature erythrocytes among total erythrocytes(%)
♀	6	2000	0	0	51.0
♀	16	2000	0	0	61.5
♀	12	2000	0	0	66.5
♀	13	2000	3	1.5	60.0
♀	57	2000	0	0	68.0
♂	3	2000	1	0.5	53.0
♂	4	2000	2	1	71.0
♂	12	2000	2	1	84.0
♂	15	2000	0	0	70.0
♂	16	2000	2	1	59.5

 

 

 

 

 

The detailed data of each animal (2100mg/kg )

Table 5

Gender	No. of animal	Number of cells analysed	Number of micronucleated immature erythrocytes	Proportion of micronucleated immature erythrocytes (‰)	Proportion of immature erythrocytes among total erythrocytes (%)
♀	1	2000	0	0	70.0
♀	9	2000	3	1.5	75.6
♀	10	2000	0	0	73.0
♀	19	2000	3	1.5	75.6
♀	20	2000	2	1	62.0
♂	5	2000	0	0	49.5
♂	6	2000	1	0.5	73.0
♂	10	2000	1	0.5	81.0
♂	13	2000	0	0	62.5
♂	17	2000	0	0	67.5

 

 

 

 

 

The detailed data of each animal (positive group )

Table 6

Gender	No. of animal	Number of cells analysed	Number of micronucleated immature erythrocytes	Proportion of micronucleated immature erythrocytes (‰)	Proportion of immature erythrocytes among total erythrocytes(%)
♀	3	2000	56	28	58.0
♀	5	2000	65	32.5	62.0
♀	7	2000	44	22	63.5
♀	15	2000	29	14.5	60.3
♀	27	2000	27	13.5	60.0
♂	2	2000	8	4	45.0
♂	9	2000	11	5.5	50.5
♂	14	2000	50	25	79.5
♂	25	2000	18	9	32.5
♂	27	2000	44	22	65.0

 

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): negative
Pepton 22 has been show to be not mutagenic