Magnesium potassium titanium oxide

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro cytogenicity / chromosome aberration study in mammalian cells

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

experimental study

Adequacy of study:

key study

Study period:

13 December 2000-01 March 2001

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study has been performed according to OECD and EC guidelines and according to GLP principles.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2001

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)

Version / remarks:

(1997)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.10 (Mutagenicity - In Vitro Mammalian Chromosome Aberration Test)

Version / remarks:

(2000)

GLP compliance:

yes

Type of assay:

in vitro mammalian chromosome aberration test

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

436-900-9

EC Name:

-

Cas Number:

39290-90-9

Molecular formula:

Hill Empirical formula: K(0.2-0.7) Mg(0.4) Ti(1.6) O(3.7-3.95) CAS Empirical formula: K(0.2-0.7) Mg(0.4) Ti(1.6) O(3.7-3.95)

IUPAC Name:

Magnesium Potassium Titanium Oxide

Details on test material:

Batch: 0G99
White powder
Expiry date: 21 August 2001
Specific gravity: 3.38
Test substance storage: At room temperature in the dark

Method

Species / strain

Species / strain / cell type:

mammalian cell line, other: Cultured peripheral human lymphocytes

Metabolic activation:

with and without

Metabolic activation system:

S9 liver homogenate of rat treated with Aroclor 1254

Test concentrations with justification for top dose:

DOSE RANGE FINDING: 1-3-10-33-100 µg/ml (with and without S9-mix)
FIRST AND SECOND CYTOGENETIC ASSAY: 10-33-100 µg/ml (with and without S9-mix)

Vehicle / solvent:

Dimethyl sulfoxide. TERRACESS P was suspended in dimethyl sulfoxide and treated with ultrasonic waves to obtain a homogeneous suspension. The final concentration of the solvent in the culture medium amounted 1.0 % (v/v).

Controls

Controls 1

Untreated negative controls:

yes

Remarks:

Dimethyl sulfoxide

Positive controls:

yes

Positive control substance:

mitomycin C

Remarks:

without S9 mix

Migrated to IUCLID6: in HBSS without calcium and magnesium: 0.5 µg/ml ( 3 h exposure); 0.2 µg/ml ( 24 h exposure); 0.1 µg/ml ( 48 h exposure)

Controls 2

Positive control substance:

cyclophosphamide

Remarks:

with S9 mix

Migrated to IUCLID6: in HBSS without calcium and magnesium. 15 µg/ml ( 3 h exposure, 24 h fixation)

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium

DURATION
- Preincubation period: 48h
- Exposure duration: 3h (with and without S9 mix), 24 h or 48 h (without S9 mix)
- Fixation time (start of exposure up to fixation or harvest of cells): 24 h or 48 h
First test: 24h (3h exposure) with and without S9-mix.
Second test: 24h (24h exposure) and 48h (48 h exposure) without S9-mix. 48h (3h exposure) with S9-mix.

SPINDLE INHIBITOR (cytogenetic assays): colchicine

NUMBER OF REPLICATIONS: duplicates in two independent experiments

NUMBER OF CELLS EVALUATED: 100 metaphase chromosome spreads per culture

DETERMINATION OF CYTOTOXICITY
- Method: mitotic index of each culture was determined by counting the number of metaphases per 1000 cells.

OTHER EXAMINATIONS:
- Determination of polyploidy: yes
- Determination of endoreplication: yes

Evaluation criteria:

A test substance was considered positive (clastogenic) in the chromosome aberration test if:
a) it induced a dose-related statistically significant (Chi-square test, P < 0.05) increase in the number of cells with chromosome aberrations.
b) a statistically significant increase in the frequencies of the number of cells with chromosome aberrations was observed in the absence of a clear dose-response relationship.

A test substance was considered negative (not clastogenic) in the chromosome aberration test if none of the tested concentrations induced a statistically significant (Chi-square test, P < 0.05) increase in the number of cells with chromosome aberrations.

Statistics:

The incidence of aberrant cells (cells with one or more chromosome aberrations, inclusive or exclusive gaps) for each exposure group was compared to that of the solvent control using Chi-square statistics.

Results and discussion

Test results

Test results 1

Species / strain:

lymphocytes: human peripheral

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Test results 2

Species / strain:

lymphocytes: human peripheral

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Remarks:

precipitation at 100 ug/l

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: at doses of 100 µg/ml

RANGE-FINDING/SCREENING STUDIES: no effects observed

Remarks on result:

other: other: dose range finding test

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Both in the absence and presence of S9-mix TERRACESS P did not induce a statistically or biologically significant increase in the number of cells with chromosome aberrations in two independently repeated experiments.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative with metabolic activation
negative without metabolic activation

TERRACESS P is not clastogenic in human lymphocytes with and without S9 mix tested, in the concentration range 10 up to and including 100 µg/plate.