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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Remarks:
Type of genotoxicity: gene mutation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1984
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
Test method is based on Japanese Labor Safety & Hygiene Law and Judgement method is based on the draft on the guidance of toxicity studies of drugs animal experiment guidance concerning with Safety of drugs by Walfare Ministry Scientific Finance in 1981.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1984
Report Date:
1984

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
JAPAN: Guidelines for Screening Mutagenicity Testing Of Chemicals
Deviations:
yes
Remarks:
species/strain: S.typhimurium (TA 1535, TA1537, TA98 and TA 100)
Principles of method if other than guideline:
Method: other: In accordance with the Labour Safety & Hygien Law Excusion Criterion.
GLP compliance:
no
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
purity: 99.5%

Method

Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Additional strain / cell type characteristics:
other:
Species / strain / cell type:
E. coli WP2 uvr A
Metabolic activation:
with and without
Metabolic activation system:
S-9 was purchased from Oriental Yeast Co.,Ltd.
Test concentrations with justification for top dose:
10 micro gram /plate: where antibacterial activity were shown
Vehicle / solvent:
DMSO
Controls
Negative solvent / vehicle controls:
yes
Remarks:
DMSO
Positive controls:
yes
Positive control substance:
2-nitrofluorene
Remarks:
Migrated to IUCLID6: N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG), 2-nitrofluorene (2-NF), 9-aminoacridine hydrochloride (ACR), 2-aminoanthracene (2-AA)
Details on test system and experimental conditions:
IUCLID4 Type: Ames test
Evaluation criteria:
Labor Safety & Hygiene Law Excusion Criterion
Statistics:
Guideline of toxicity studies of drugs by Welfare Ministry Scientific Finance in 1981

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
other: 10 micro gram/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
E. coli WP2 uvr A
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
other: 10 micro gram/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
TEST-SPECIFIC CONFOUNDING FACTORS
- Effects of pH:
- Effects of osmolality:
- Evaporation from medium:
- Water solubility: insoluble
- Precipitation:
- Other confounding effects:


RANGE-FINDING/SCREENING STUDIES: Since antibacterial activity was observed at 5,000 ug/disc, the maximum concentration in execution ceiterion, maximum concentration for the present test was set at 10 ug/Plate at which the test material was slightly antibacterial.


COMPARISON WITH HISTORICAL CONTROL DATA:


ADDITIONAL INFORMATION ON CYTOTOXICITY:
Remarks on result:
other: other:
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

Results of the bacterial reversion test (+S9)

concentration: 0.01, 0.05, 0.1, 0.5, 1,5, 10 ug/plate

Species DMSO Substance Positive control

----------------------------------------------------------

TA100: 181 -151 134 492

TA1535: 16 -19 17 198

WP2uvrA: 19 -28 20 209

TA98: 21 -26 25 387

TA1537: 8 -11 9 228

TA1538: 21 -28 24 239

----------------------------------------------------------

Results of the bacterial reversion test (-S9)

concentration: 0.01, 0.05, 0.1, 0.5, 1,5, 10 ug/plate

Species DMSO Substance Positive control

----------------------------------------------------------

TA100 103 -121 111 438

TA1535 17 -24 17 253

WP2uvrA 17 -22 19 228

TA98 15 -21 17 263

TA1537 6 -10 8 229

TA1538 14 -24 20 225

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Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

This substance was judged to be not mutagenic on the basis of the creteria in the guideline of toxicity studies of drugs (drft)
Executive summary:

In a reverse gene mutation assay in bacteria, strains TA100, TA1535, TA98, TA1537, TA1538 of S. typhimurium and E.coli WP2uvrA were exposed to PMI (provided by NIPPON SHOKUBAI on 1984.02.22) include DMSO at concentrations of 0, 0.01, 0.05, 0.1, 0.5, 1, 5, 10 μg/plate in the presence and absence of mammalian metabolic activation. 

  Since PMI showed antibacterial action at the concentration level of 5,000 ug/plate, the maximum concentration in the present test was set at 10 ug/plate at which this substance was slightly antibacterial.

The positive controls induced the appropriate responses in the corresponding strains.  There was no evidence of induced mutant colonies over background.

Genetic toxicity data (Amest and Chromosome aberration) show negative with the test sample provided by NIPPON SHOKUBAI.

Genetic toxicity data (Amest and Chromosome aberration) show positive with the test sample provided by Daihachi Chemical.

The submitter considered that this diffence on result may cause due to the difference smallamount of impurity between two samples

Based on REACH Guidance R.7a Table R.7.7-1, appropriate in vivo mutagenicity studies shall be considered in case of another submitter whose purity is different from above 2 samples..

However, the positive result is considered as equivocal due to these positive findings generated only at highly toxic/cytotoxic concentrations. (REACH Guidance R.7a R.7.4.1)

So, Based on the weight of evidence, the mutagenicity of this substance is considered as negative in vitro.

 

This study is classified as acceptable.  This study is equivalent to the requirement for JAPAN: Guidelines for Screening Mutagenicity Testing (bacterial reverse gene mutation) of Chemicals.