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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
data from handbook or collection of data
Justification for type of information:
Data is from peer reviewed journals

Data source

Reference
Reference Type:
publication
Title:
Mutagenicity testing of the test chemical and its various derivatives
Author:
Minako Nagao et.al
Year:
1977
Bibliographic source:
Mutation Research, 1977

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
other: as mentioned below
Principles of method if other than guideline:
Bacterial reverse mutation assay was performed to evaluate the toxic nature of the test chemical on Salmonella typhimurium TA98 and TA100 strains.
GLP compliance:
not specified
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
4,7-dichloroquinoline
EC Number:
201-714-7
EC Name:
4,7-dichloroquinoline
Cas Number:
86-98-6
Molecular formula:
C9H5Cl2N
IUPAC Name:
4,7-dichloroquinoline
Test material form:
solid: particulate/powder
Details on test material:
- Name of test material: 4,7 Dichloroquinoline
- IUPAC name: 4, 7 Dichloroquinoline
- Molecular formula: C9H5Cl2N
- Molecular weight: 198.051 g/mole
- Smiles : c12c(cc(Cl)cc2)nccc1Cl
- Inchl: 1S/C9H5Cl2N/c10-6-1-2-7-8(11)3-4-12-9(7)5-6/h1-5H
- Substance type: Organic
- Physical state: Solid powder (pale cream)
- Purity: 99.4%(by GC)

Method

Target gene:
Histidine
Species / strain
Species / strain / cell type:
other: Salmonella typhimurium TA100 and TA 98
Details on mammalian cell type (if applicable):
Not applicable
Additional strain / cell type characteristics:
other: Base-pair-change mutant and frameshift mutant. Both strains have the R-factor of pKM101 as a plasmid
Cytokinesis block (if used):
No data
Metabolic activation:
with and without
Metabolic activation system:
Type and composition of metabolic activation system: The S-9 fraction was prepared aseptically by centrifugation of the liver homogenate (25% in 0.15 M KCl) at 9000 g for 10 min as described by Ames et al.
- source of S9 : Male Sprague-Dawley rats weighing 100-120 g were injected intraperitoneally with polychlorinated biphenyl (Kanechlor 500) at a dose of 50 mg/100 g body weight, five days before they were killed
- concentration or volume of S9 mix and S9 in the final culture medium : S-9 mix contained 50 µmol of sodium phosphate buffer (pH 7.4), 4 µmol of MgCl2, 16.5 µmol of KCI, 2.5µmol of glucose-6-phosphate, 2 µmol of NADH, 2 µmol of NADPH, 2.5 µmol of ATP and 150µmol of S-9 fraction in a total volume of 0.5 ml.
Test concentrations with justification for top dose:
0, 0.5 or 1.0 µmoles/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: The test chemical was stable and soluble in DMSO.
Controls
Untreated negative controls:
not specified
Negative solvent / vehicle controls:
yes
Remarks:
DMSO
True negative controls:
not specified
Positive controls:
not specified
Positive control substance:
not specified
Details on test system and experimental conditions:
NUMBER OF REPLICATIONS:
- Number of cultures per concentration (single, duplicate, triplicate) : no data available
- Number of independent experiments : no data available

METHOD OF TREATMENT/ EXPOSURE:
- Cell density at seeding (if applicable):
- Test substance added in medium; in agar (plate incorporation); preincubation; in suspension; as impregnation on paper disk : pre-incubation

TREATMENT AND HARVEST SCHEDULE
- Preincubation period, if applicable: 20 minutes
- Exposure duration/duration of treatment: 2 days
- Harvest time after the end of treatment (sampling/recovery times):
Rationale for test conditions:
No data
Evaluation criteria:
After 2-day incubation, colonies of histidine prototroph were counted as revertants.
Statistics:
No data

Results and discussion

Test resultsopen allclose all
Species / strain:
other: Salmonella typhimurium TA100 and TA 98
Metabolic activation:
with
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not specified
Vehicle controls validity:
valid
Untreated negative controls validity:
not specified
True negative controls validity:
not specified
Positive controls validity:
not specified
Species / strain:
other: S. typhimurium TA 100, S. typhimurium TA 98
Metabolic activation:
without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not specified
Vehicle controls validity:
valid
Untreated negative controls validity:
not specified
True negative controls validity:
not specified
Positive controls validity:
not specified
Additional information on results:
Ames test: The test chemical was weakly mutagenic to both strains with S-9 mix and non mutagenic to both strains in the absence of S9 mix. Though there was weak mutagenic activity in the presence of S9 mix but dose dependent decrease in number of revertants was observed. Hence, we consider the test chemical can be considered to be non-mutagenic both in the presence and absence of S9 mix to S.Typhimurium TA 98 and TA 100 strains.
Remarks on result:
other: non-mutagenic

Applicant's summary and conclusion

Conclusions:
The test chemical was weakly mutagenic to both strains with S-9 mix and non mutagenic to both strains in the absence of S9 mix. Though there was weak mutagenic activity in the presence of S9 mix but dose dependent decrease in number of revertants was observed. Hence, the test chemical can be considered to be non-mutagenic both in the presence and absence of S9 mix to S.Typhimurium TA 98 and TA 100 strains.
Executive summary:

In vitro genetic toxicity study was performed to determine the mutagenic nature of the test chemical. Strains TA100 and TA98 of Salmonella typhimirium were used as the tester strains. Assay was carried out as described by Ames et al. with some modifications. The test chemical was freshly dissolved in 100 µl of DMSO were pre-incubated at 37°C for 20 min with 0.5 ml of S-9 mix or 0.5 ml of 0.1 M sodium phosphate buffer (pH 7.4) and 0.1 ml of bacterial culture. Two ml of molten soft agar at 45°C were added, and the resulting mixture was poured over 25 ml of minimal-glucose agar containing 0.1 µmol of L-histidine and 0.1 µmol of biotin. After 2-day incubation, colonies of histidine prototroph were counted as revertants. The test chemical was weakly mutagenic to both strains with S-9 mix and non mutagenic to both strains in the absence of S9 mix. Though there was weak mutagenic activity in the presence of S9 mix but dose dependent decrease in number of revertants was observed. Hence, the test chemical can be considered to be non-mutagenic both in the presence and absence of S9 mix to S.Typhimurium TA 98 and TA 100 strains.