Registration Dossier

Administrative data

Endpoint:
in vivo mammalian cell study: DNA damage and/or repair
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
1991
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference
Reference Type:
publication
Title:
Evaluation of DNA-binding activity of hydroxyanthraquinones occuring in Rubia tinctorum L
Author:
B. Poginsky et al.
Year:
1991
Bibliographic source:
Carcinogenesis vol. 12 no. 7, pp. 1265 - 1271
Report Date:
1991

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Principle of test: In the present study they have investigated by 32P-postlabelling the possible binding to DNA of test substance in vivo, following oral administration of the test substance in mice.
GLP compliance:
no
Type of assay:
other: DNA-binding activity: 32P-postlabelling assay (detection of covalent binding of chemical carcinogens to DNA in animals and humans)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder

Test animals

Species:
mouse
Strain:
other: Parkers
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: National Institute for Medical Research, Mill Hill, London
- Age at study initiation: 4-6 weeks
- Weight at study initiation: n.a.
- Fasting period before study: deprived of food each evening, the compounds was administered the following morning
- Housing: n.a.
- Diet (e.g. ad libitum): ad libitum for the rest of the day
- Water (e.g. ad libitum): ad libitum
- Acclimation period: n.a.

Administration / exposure

Route of administration:
oral: feed
Vehicle:
- Concentration of test material : 10mg

Details on exposure:
DIET PREPARATION
- Rate of preparation of diet (frequency):1/day
- Mixing appropriate amounts with (Type of food): cheese spread (1g)
- Storage temperature of food: n.a.
Duration of treatment / exposure:
4 days
Frequency of treatment:
1/day
Post exposure period:
4 hours after the last administration the mice were killed
Doses / concentrations
Dose / conc.:
10 other: mg/day
No. of animals per sex per dose:
2 animals per group, one dose
Control animals:
yes, concurrent vehicle
Positive control(s):
none

Examinations

Tissues and cell types examined:
Liver, kidney, duodenum and colon were removed and stored at -70°C until DNA isolation

Results and discussion

Test results
Key result
Sex:
male
Genotoxicity:
negative
Toxicity:
not specified
Vehicle controls valid:
yes
Additional information on results:
The 32P-postlabelling analysis of hepatic DNA from mice treated with the test item does not show evidence of radioactive spot other than those seen in control DNA.
The kidney DNA from mice treated with the test substance showed a similar pattern to that of the control group.

Applicant's summary and conclusion

Conclusions:
The test substance does not form DNA adducts in mice liver, kidney, duodenum and colon.
Executive summary:

In the present study, they have investigated by32P-postlabelling the possible binding to DNA of 1,2 -dihydroantraquinone in vivo, following the treatment of males Parkes mice, 4 -6 weeks old. The32P-postlabelling assay is a method to detect covalent binding of chemical carcinogens to DNA in animals and humans.

Duplicate group of two animals/group were deprived of food each evening and the compounds (10mg/d) were administered mixed with cheese spread (1g) the following morning. Thereafter, the mice received standard lab diet ad libitum for the rest of the day. The mice were treated for 4 days; the controls received cheese spread only. Four hours after the last administration, the mice were killed. Liver, kidney, duodenum and colon were removed and store at -70°C until DNA isolation.

The thawed tissues sample were homogenized and the DNA were isolated and labelled by32-P-postlabelling. The DNA adducts were measured by chromatography. The presence of radiolabelled adducts on the chromatograms was detected by autoradiography. The levels of adducts in DNA samples were determined from the amount of radioactivity present in the adduct spot, measured by Cerenkov counting32P-ATP used in the labelling reaction.

In conclusion, the32P-postlabelling of DNA from mice treated with the test substance did not give rise of DNA adducts in mice liver, kidney, duodenum and colon.