Barium tartrate

Genetic toxicity: in vitro

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:

November 10, 2014 - November 24, 2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study has been performed according to OECD and/or EC guidelines and according to GLP principles.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

(1997)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)

Version / remarks:

(2008)

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Barium tartrate

EC Number:

227-615-9

EC Name:

Barium tartrate

Cas Number:

5908-81-6

Molecular formula:

C4H4O6Ba

IUPAC Name:

Barium L(+)-(2R,3R)-tartrate

Details on test material:

- Name of test material (as cited in study report): Barium tartrate
- Appearance: White powder

Method

Target gene:

- S. typhimurium: Histidine gene
- E. coli: Tryptophan gene

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Species / strain 2

Species / strain / cell type:

E. coli WP2 uvr A

Metabolic activation:

with and without

Metabolic activation system:

Rat liver S9-mix induced by Aroclor 1254

Test concentrations with justification for top dose:

Experiment 1
Preliminary test (without and with 5% (v/v) S9-mix):
TA100: 1.7, 5.4, 17, 52, 164, 512, 1600 and 5000 µg/plate
WP2uvrA: 1.7, 5.4, 17, 164, 512, 1600 and 5000 µg/plate
Main study: TA1535, TA1537 and TA98:
Without and with 5% (v/v) S9-mix: 52, 164, 512, 1600 and 5000 µg/plate
Experiment 2:
Without and with 10% (v/v) S9-mix: 492, 878, 1568, 2800 and 5000 µg/plate

Vehicle / solvent:

- Vehicle used: DMSO

Controls

Negative solvent / vehicle controls:

yes

Remarks:

(DMSO)

Positive controls:

yes

Positive control substance:

other: see section "Any other information on materials and methods incl. tables"

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Exposure duration: 48 hour

NUMBER OF REPLICATIONS:
- Doses of the test substance were tested in triplicate in each strain. Two independent experiments were conducted.

NUMBER OF CELLS EVALUATED: 10E8 cells per plate

DETERMINATION OF CYTOTOXICITY
- Method: The reduction of the bacterial background lawn, the increase in the size of the microcolonies and the reduction of the revertant colonies.

OTHER EXAMINATIONS:
- The presence of precipitation of the test compound on the plates was determined.

Evaluation criteria:

A test substance is considered negative (not mutagenic) in the test if:
a) The total number of revertants in tester strain TA100 is not greater than two (2) times the concurrent vehicle control, and the total number of revertants in tester strains TA1535, TA1537, TA98 or WP2uvrA is not greater than three (3) times the concurrent vehicle control.
b) The negative response should be reproducible in at least one independently repeated experiment.

A test substance is considered positive if:
a) The total number of revertants in the tester strain TA100 is greater than two (2) times the concurrent vehicle control, or the total number of revertants in tester strains TA1535, TA1537, TA98 or WP2uvrA is greater than three (3) times the concurrent vehicle control
b) In case a follow up experiment is performed when a positive response is observed in one of the tester strains, the positive response should be reproducible in at least one follow up experiment.

Results and discussion

Test results

Test results 1

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:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

valid

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation (dose range finding test): Precipitation of Barium tartrate on the plates was observed at the start and end of the incubation period at the concentration of 5000 μg/plate. With the exception of tester strain WP2uvrA in the absence of S9-mix, where no precipitate was observed at the end of the incubation period.
- Precipitation (first experiment): Precipitation of Barium tartrate on the plates was observed at the start of the incubation period at the concentration 5000 μg/plate and no precipitate was observed at the end of the incubation period.
- Precipitation (second experiment): Precipitation of Barium tartrate on the plates was observed at the start of the incubation period at concentrations of 2800 and 5000 μg/plate and no precipitate was observed at the end of the incubation period. With the exception of tester strain TA100 in the absence of S9-mix, where no precipitate was observed at the start and at the end of the incubation period.

RANGE-FINDING/SCREENING STUDIES:
- No toxicity or mutagenicity was observed up to and including the top dose of 5000 µg/plate

COMPARISON WITH HISTORICAL CONTROL DATA:
- The negative control values were within the laboratory historical control data ranges
- The strain-specific positive control values were within the laboratory historical control data ranges indicating that the test conditions were adequate and that the metabolic activation system functioned properly, except the response for TA1537 in the first experiment in the absence of S9-mix. The value (1080) was above the limit of the range (998). Since the value was more than 3 times greater than the concurrent solvent control values, this had no effect on the results of the study.

ADDITIONAL INFORMATION ON CYTOTOXICITY:
- No toxicity or mutagenicity was observed up to and including the top dose of 5000 µg/plate

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

The mutagenic activity of Barium tartrate was evaluated in accordance with OECD 471 (1997) and according to GLP principles. Based on the results of this study it is concluded that the substance is not mutagenic in the Salmonella typhimurium reverse mutation assay and in the Escherichia coli reverse mutation assay with and without metabolic activation.

Executive summary:

The mutagenic activity of Barium tartrate was evaluated in accordance with OECD 471 (1997) and according to GLP principles. The test was performed in two independent experiments, both in the absence and presence of S9-mix. The substance was tested up to and including 5000 µg/plate in all tester strains. Adequate solvent and positive controls were included. The substance did not induce a significant dose-related increase in the number of revertant (His+) colonies in each of the four S. typhimurium tester strains (TA1535, TA1537, TA98 and TA100) and in the number of revertant (Trp+) colonies in tester strain WP2uvrA, both in the absence and presence of S9-metabolic activation. These results were confirmed in independently repeated experiments. Based on the results of this study it is concluded that the substance is not mutagenic in the Salmonella typhimurium reverse mutation assay and in the Escherichia coli reverse mutation assay with and without metabolic activation.