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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:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report date:
2018

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EPA OPPTS 870.5100 - Bacterial Reverse Mutation Test (August 1998)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
Vanadate(1-), oxo[phosphato(3-)-.kappa.O]-, hydrogen, hydrate (2:1)
EC Number:
618-920-1
Cas Number:
93280-40-1
Molecular formula:
H2 O .2 H .2 O5 P V
IUPAC Name:
Vanadate(1-), oxo[phosphato(3-)-.kappa.O]-, hydrogen, hydrate (2:1)
Test material form:
solid: particulate/powder

Method

Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Details on mammalian cell type (if applicable):
CELLS USED
- Source of cells: The Salmonella strains TA 1535, TA 100, TA 1537 and the Escherichia coli strain were obtained from Moltox Molecular Toxicology, Inc.; Boone, NC 28607; USA on 02 Dec 2014. The Salmonella strain TA 98 was obtained from Moltox Molecular Toxicology on 07 Jan 2015.
Species / strain / cell type:
E. coli WP2 uvr A
Details on mammalian cell type (if applicable):
The Escherichia coli strain were obtained from Moltox Molecular Toxicology, Inc.; Boone, NC 28607; USA on 02 Dec 2014.
Metabolic activation:
with and without
Metabolic activation system:
S9 fraction (rat liver)
Test concentrations with justification for top dose:
First experiment (standard plate test): 0; 33; 100; 333; 1000; 2500 and 5000 μg/plate
Second experiment (standard plate test): 0; 0.33; 1; 3.3; 10; 33 and 100 μg/plate (without S9 mix), 0; 1; 3.3; 10; 33; 100 and 333 μg/plate (with S9 mix) - Bacteriotoxicity was observed in the standard plate test, therefore the doses were adjusted.
Third experiment (Preincubation): 0; 0.33; 1; 3.3; 10; 33 and 100 μg/plate (TA strains without S9 mix), 0; 1; 3.3; 10; 33; 100 and 333 μg/plate (TA strains with S9 mix), 0; 33; 100; 333; 1000; 2500 and 5000 μg/plate (E. coli) - No mutagenicity was observed in the standard plate test. Due to
toxicity, the doses were adjusted in the preincubation test.
Fourth experiment (Preincubation): 0; 1; 3.3; 10; 33; 100 and 333 μg/plate (TA 100) - No mutagenicity was observed in the preincubation test. However, the expected toxicity was not observed with the strain TA 100 without S9 mix and this experimental part was repeated with higher doses.
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: water
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Positive control substance:
4-nitroquinoline-N-oxide
9-aminoacridine
other: N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), 4-nitro-o-phenylenediamine (NOPD), 2-Aminoanthracene (2-AA)
Details on test system and experimental conditions:
STANDARD PLATE TEST

The experimental procedure of the standard plate test (plate incorporation method) was based on the method of Ames et al. (1, 2).
- Salmonella typhimurium
Test tubes containing 2-mL portions of soft agar (overlay agar), which consists of 100 mL agar (0.8% [w/v] agar + 0.6% [w/v] NaCl) and 10 mL amino acid solution (minimal amino acid solution for the determination of mutants: 0.5 mM histidine + 0.5 mM biotin) were kept
in a water bath at about 42 - 45°C, and the remaining components were added in the following order:
0.1 mL test solution or vehicle (negative control)
0.1 mL fresh bacterial culture
0.5 mL S9 mix (with metabolic activation)
or
0.5 mL phosphate buffer (without metabolic activation)
After mixing, the samples were poured onto Minimal glucose agar plates (Moltox Molecular Toxicology, Inc.; Boone, NC 28607; USA) within approx. 30 seconds.
After incubation at 37°C for 48 – 72 hours in the dark, the bacterial colonies (his+ revertants) were counted. The colonies were counted using the Sorcerer Image Analysis System with the software program Ames Study Manager (Perceptive Instruments Ltd., Haverhill, UK). Colonies were counted manually, if precipitation of the test substance hinders the counting using the Image Analysis System.

- Escherichia coli
Test tubes containing 2-mL portions of soft agar (overlay agar), which consists of 100 mL agar (0.8% [w/v] agar + 0.6% [w/v] NaCl) and 10 mL amino acid solution (minimal amino acid solution for the determination of mutants: 0.5 mM tryptophan) were kept in a water bath at about 42 - 45°C, and the remaining components were added in the following order:
0.1 mL test solution or vehicle (negative control)
0.1 mL fresh bacterial culture
0.5 mL S9 mix (with metabolic activation)
or
0.5 mL phosphate buffer (without metabolic activation)
After mixing, the samples were poured onto Minimal glucose agar plates (Moltox Molecular Toxicology, Inc.; Boone, NC 28607; USA) within approx. 30 seconds.
After incubation at 37°C for 48 – 72 hours in the dark, the bacterial colonies (trp+ revertants) were counted. The colonies were counted using the Sorcerer Image Analysis System with the software program Ames Study Manager (Perceptive Instruments Ltd., Haverhill, UK). Colonies were counted manually, if precipitation of the test substance hinders the counting using the Image Analysis System.

PREINCUBATION TEST:
The experimental procedure was based on the method described by Yahagi et al. (7) and Matsushima et al. (8).
0.1 mL test solution or vehicle, 0.1 mL bacterial suspension and 0.5 mL S9 mix (with metabolic activation) or phosphate buffer (without metabolic activation) were incubated at 37°C for the duration of about 20 minutes using a shaker. Subsequently, 2 mL of soft agar was added and, after mixing, the samples were poured onto the agar plates within approx. 30 seconds.
After incubation at 37°C for 48 – 72 hours in the dark, the bacterial colonies were counted. The colonies were counted using the Sorcerer Image Analysis System with the software program Ames Study Manager (Perceptive Instruments Ltd., Haverhill, UK). Colonies were counted manually, if precipitation of the test substance hindered the counting using the Image Analysis System.

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium TA 1535
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
from 100 ug/plate onward
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 1537
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
from 33 ug/plate onward
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 98
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
from 33 ug/plate onward
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
from 333 ug/plate onward
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:
no cytotoxicity, but tested up to precipitating concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
Precipitation of the test substance was found from about 333 μg/plate onward in the standard plate test and from about 1000 μg/plate onward in the preincubation test both with and without S9 mix.

A strong bacteriotoxic effect was observed depending on the strain and test conditions from about 33 μg/plate onward.

A relevant increase in the number of his+ or trp+ revertants (factor ≥ 2: TA 100, TA 98 and E.coli WP2 uvrA or factor ≥ 3: TA 1535 and TA 1537) was not observed in the standard plate test or in the preincubation test without S9 mix or after the addition of a metabolizing system.

Applicant's summary and conclusion

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