Registration Dossier

Administrative data

Endpoint:
in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus
Remarks:
Type of genotoxicity: chromosome aberration
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2007-08-08 - 2008-04-03
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: non-GLP guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2008
Report Date:
2008

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
Deviations:
no
GLP compliance:
yes
Type of assay:
chromosome aberration assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): DCBS
- Substance type: organic
- Physical state: white powder

Test animals

Species:
mouse
Strain:
other: Kun-ming Mouse, SPF
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Age at study initiation: no data
- Weight at study initiation: 25—30g
- Assigned to test groups randomly: Yes
- Fasting period before study: no data
- Housing: Male and female mice were fed in separate cages (L46 X W31 xH20cm). The cages were changed twice each week.

- Diet (e.g. ad libitum):
Feed was offered freely throughout the study period.

- Water (e.g. ad libitum): Water was offered freely throughout the study period.
- Acclimation period: no data

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ±3 °C
- Humidity (%): 30—70 %
- Air changes (per hr): No data
- Photoperiod (hrs dark / hrs light): 12 hours light and 12 hours dark.

IN-LIFE DATES: From: To: no data

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
- Vehicle(s)/solvent(s) used: vegetable oil
- Justification for choice of solvent/vehicle: no data
- Concentration of test material in vehicle: 5000 mg, 2500mg, 1250 mg / 40 mL
- Amount of vehicle (if gavage or dermal): 40 mL
Details on exposure:
PREPARATION OF DOSING SOLUTIONS:
According to the doses design, 5000 mg, 2500 mg and 1250 mg of testing article were taken and then was-added with vegetable oil to 40 mL, misce bene for test.
The three doses of reagents, positive control (cyclophosphamide, 40mg/kg) and negative control (vegetable oil 20mL/kg) were administrated intragastrically respectively to the five groups, at a proportion of 0.4mL/20g weight. Animals from each group are sacrificed at 24, 36 and 48 hours after administration.
Duration of treatment / exposure:
24, 36 and 48 hours
Frequency of treatment:
gavage in one time
Post exposure period:
Animals from each group were sacrificed at 24, 36 and 48 hours after administration
Doses / concentrations
Remarks:
Doses / Concentrations:
5000 mg/kg, 2500mg/kg, 1250mg/kg
Basis:
nominal conc.
No. of animals per sex per dose:
15 male and 15 female
Control animals:
yes, concurrent vehicle
Positive control(s):
cyclophosphamide
- Justification for choice of positive control(s): no data
- Route of administration: gavage
- Doses / concentrations: 40mg/kg

Examinations

Tissues and cell types examined:
Bone marrow from femora
Details of tissue and slide preparation:
CRITERIA FOR DOSE SELECTION: no data

TREATMENT AND SAMPLING TIMES ( in addition to information in specific fields):
Bone marrow is removed from femora of all animals and then made into slides with calf serum.

DETAILS OF SLIDE PREPARATION:
The slide is prepared, fixed and stained with Giemsa

METHOD OF ANALYSIS:
Record the number of PCEs(polychromatic erytrocytes) which contain micronucleus of the 2000 PCEs per mouse. Calculate the permil of the cells containing micronucleus. Count the 200 PCE as well and the NCE, calculating the PCE/NCE ratio.
Evaluation criteria:
No data
Statistics:
Using chi-square criterion to analyze the micronucleus percent of each group with negative control group statistically

Results and discussion

Test results
Sex:
male/female
Genotoxicity:
negative
Toxicity:
no effects
Vehicle controls validity:
valid
Negative controls validity:
other: Negative control is the vehicle control
Positive controls validity:
valid
Additional information on results:
RESULTS OF RANGE-FINDING STUDY
- no preliminary test recorded

RESULTS OF DEFINITIVE STUDY
- the ratio of Micronucleus and PCE/ NCE of test group have no obvious difference comparing with negative control (vehicle control) group. And the positive control show obvious difference.
- The mouse weight change of the test group has no obvious differece comparing with negative control (vehicle control) group and positive control.

Applicant's summary and conclusion

Conclusions:
Interpretation of results: negative
No toxic effect of the test item was observed in the experimental conditions, therefore, the genetic toxicity of test item is considered to negative.