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Toxicological information

Genetic toxicity: in vivo

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Administrative data

Endpoint:
in vivo mammalian cell study: DNA damage and/or repair
Remarks:
Type of genotoxicity: DNA damage and/or repair
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2000
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Non GLP, no guideline mentioned but equivalent to guideline study, animal experimental study, minor restrictions in design and/or reporting but otherwise adequate for assessment.

Data source

Reference
Reference Type:
publication
Title:
Lack of effect of furfural on DNA unscheduled DNA synthesis in the in vivo rat and mouse hepatocyte DNA repair assays and in precision-cut human liver slices.
Author:
Lake BG, Edwards AJ, Price RJ, Phillips BJ, Renwick AB, Beamond JA, Adams TB
Year:
2001
Bibliographic source:
Food and Chemical Toxicology 39, 999-1011.

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 486 (Unscheduled DNA Synthesis (UDS) Test with Mammalian Liver Cells in vivo)
GLP compliance:
not specified
Type of assay:
unscheduled DNA synthesis

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Furfural
- Supplier: International Flavors and Fragrance (IFF), Union Beach, NJ, USA
- code: IFF Product Code 06239
- Analytical purity: ≥98.0%

Test animals

Species:
rat
Strain:
Fischer 344
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Harlan Olac (Bicester, Oxon, UK)
- Housing: polypropylene cages with stainless steel grid tops and floors
- Diet: R and M No.1 Laboratory animal diet (Special Diets Services, Witham, Essex, UK) ad libitum
- Water: Water ad libitum
- Acclimation period: at least 7 days

ENVIRONMENTAL CONDITIONS
- Temperature: 22±2°C
- Humidity: 47-64%
- Air changes (per hr): no data
- Photoperiod: 12 hrs dark / 12hrs light

IN LIFE DATES: Not reported

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
corn oil (10 mL/kg body weight)
Details on exposure:
oral gavage
10 mL/kg bodyweight
Duration of treatment / exposure:
once
Frequency of treatment:
once
Post exposure period:
2-4 hours
12-16 hours
Doses / concentrations
Remarks:
Doses / Concentrations:
5-50 mg/kg bw
Basis:
actual ingested
No. of animals per sex per dose:
2, 4, or 6 rats per group
Control animals:
yes, concurrent vehicle
other: negative control (distilled water)
Positive control(s):
2-AAF (2-Acetylaminofluorene) 50 mg/kg body weight
DMN (Dimethylnitrosamine) 20 mg/kg body weight

Examinations

Tissues and cell types examined:
Hepatocytes
Details of tissue and slide preparation:
Isolation of hepatocytes after treatment by a collagenase perfusion technique. Viability was determined by tryptan blue exclusion.
5 cultures are prepared from one liver (2 used for USD).
Slides were prepared and stained.
Quantitative assessment of silver grains in the nuclei and cytoplasm was performed. The grains were counted for entire nucleus area and from 3 equal sized adjacent areas of cytoplasm. The net grain count was determined for each hepatocyte nucleus. 2 slides per animal were examined, 50 hepatocytes per slide. Examination was performed blind. The population average of net grains was calculated for each slide and the percentage of hepatocyte nuclei undergoing DNA repair with both >5 and >10 net grains were calculated. The proportion of nuclei undergoing replicative DNA synthesis was measured by counting at least 250 cells in random fields on each slide.
Evaluation criteria:
The population average of net grains was calculated for each slide and the percentage of hepatocyte nuclei undergoing DNA repair with both >5 and >10 net grains were calculated. The proportion of nuclei undergoing replicative DNA synthesis was measured by counting at least 250 cells in random fields on each slide.
Statistics:
Nested analysis of variance. Dose response relationships assessed by fitting linear and quadratic polynomials. Assumptions of normality and homogeneity of variance tested using normality plots and Bartlett's test for homogeneity. A t-test was used to compare negative control against known genotoxins. All tests were 2-sided at 5% level of significance, except for Bartlett's test at 1%. Fischer's Exact test used to compare % hepatocyte nuclei with >5 and >10 net grains.

Results and discussion

Test results
Sex:
male
Genotoxicity:
negative
Toxicity:
no effects
Vehicle controls validity:
valid
Negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
Furfural did not produce any statistically significant increase or any dose-related effects on UDS in rat hepatocytes, whereas UDS was markedly induced by the positive controls under these conditions, i.e. 2-4 h after dosing these species with 20 mg/kg dimethylnitrosamine and 12-16 h after treatment with 50 mg/kg 2-acetylaminofluorene.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information): negative
In an in vivo UDS test in rat, furfural did not produce any statistically significant increase or any dose-related effects on UDS in rat hepatocytes.
Executive summary:

In an in vivo UDS test, furfural was dosed by gavage at levels of 0, 5, 16.7 and 50 mg/kg bw to male F344 rats. Preliminary toxicity studies had established the top dose of 50 mg/kg in the rat as the maximum tolerated doses for this species. Hepatocytes were isolated by liver perfusion either 2-4 or 12-16 h after treatment, cultured in medium containing [3H]thymidine for 4 h and assessed for UDS by grain counting of auto radiographs.

 

Furfural did not produce any statistically significant increase or any dose-related effects on UDS in rat hepatocytes, whereas UDS was markedly induced by three positive controls under these conditions, i.e. 2-4 h after dosing these species with 20 mg/kg dimethylnitrosamine and 12-16 h after treatment with 50 mg/kg 2-acetylaminofluorene.