IPDA-BADGE-BUMGE

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:

26-Jun-2012 to 06-Oct-2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

in vitro mammalian chromosome aberration test

Test material

Test material information

Constituent 1

Details on test material:

- Name of test material (as cited in study report): 4,4’-Isopropylidenediphenol, oligomeric reaction products with 1-chloro-2,3-epoxypropane, reaction products with butan-1-ol and 3-aminomethyl-3,5,5-trimethylcyclohexylamine
- Substance type: Clear colourless viscous liquid
- Physical state: Liquid
- Storage condition of test material: At room temperature in the dark

Method

Species / strain

Species / strain / cell type:

lymphocytes: Cultured peripheral human lymphocytes

Details on mammalian cell type (if applicable):

- Type and identity of media:
Blood samples
Blood samples were collected by venapuncture using the Venoject multiple sample blood collecting system with a suitable size sterile vessel containing sodium heparin. Immediately after blood collection lymphocyte cultures were started.
- Culture medium
Culture medium consisted of RPMI 1640 medium, supplemented with 20% (v/v) heat-inactivated (56°C; 30 min) foetal calf serum, L-glutamine (2 mM), penicillin/streptomycin (50 U/mL and 50 µg/mL respectively) and 30 U/mL heparin.
- Lymphocyte cultures
Whole blood (0.4 mL) treated with heparin was added to 5 mL or 4.8 mL culture medium (in the absence and presence of S9-mix, respectively). Per culture 0.1 ml (9 mg/mL) phytohaemagglutinin was added.
- Properly maintained: yes
- Periodically checked for Mycoplasma contamination: not applicable, immediately after blood collection lymphocyte cultures were started.
- Periodically checked for karyotype stability: yes
- Periodically "cleansed" against high spontaneous background: not applicable, immediately after blood collection lymphocyte cultures were started.

Metabolic activation:

with and without

Metabolic activation system:

Rat liver S9-mix induced by a combination of phenobarbital and ß-naphthoflavone.

Test concentrations with justification for top dose:

Dose range finding test:
Without and with S9-mix, 3hr exposure; 24 hr fixation: 3, 10, 33, 100 and 333 µg/mL
Without S9-mix, 24/48hr exposure; 24/48 hr fixation: 3, 10, 33, 100, 333, 1000 and 3330 µg/mL

First cytogenetic test:
Without S9-mix, 3 h exposure time, 24 h fixation time: 70, 100 and 125 µg/mL
With S9-mix, 3 h exposure, 24 h fixation time: 100, 125 and 150 µg/mL
Second cytogenetic test:
Without S9-mix, 24 hr exposure; 24 hr fixation: 1, 20 and 40 µg/mL
Without S9-mix, 48 hr exposure; 48 hr fixation: 1, 20 and 60 µg mL
With S9-mix, 3 hr exposure; 48 hr fixation: 3, 125 and 150 µg/mL

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: Test compound was soluble in DMSO and DMSO has been accepted and approved by authorities and international guidelines

Controls

Controls 1

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

mitomycin C

Remarks:

without S9 Migrated to IUCLID6: in Hank's Balanced Salt Solution: 0.5 µg/mL for a 3 h exposure period, 0.2 µg/mL for a 24 h exposure period and 0.1 µg/mL for a 48 h exposure period

Controls 2

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

cyclophosphamide

Remarks:

with S9 Migrated to IUCLID6: in Hank's Balanced Salt Solution: 10 µg/mL

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium

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

SPINDLE INHIBITOR (cytogenetic assays): colchicine
STAIN (for cytogenetic assays): Giemsa

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, one-sided, p < 0.05) increase in the number of cells with chromosome aberrations.
b) A statistically significant and biologically relevant 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, one-sided, 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, gaps included or excluded) for each exposure group outside the laboratory historical control data range was compared to that of the solvent control using Chi-square statistics.

Results and discussion

Test results

Test results 1

Species / strain:

lymphocytes: peripheral human lymphocytes

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

other: peripheral human lymphocytes

Metabolic activation:

with

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Effects of pH: No
- Effects of osmolality: No

- Precipitation: Precipitation in the exposure medium was observed at dose levels of 150 µg/ml and above

RANGE-FINDING/SCREENING STUDIES:
- Toxicity was observed at dose levels of 100µg/ml and above in the absence of S9, 3 hr treatment/24 hr fixation; at dose levels of 33 and 100 µg/ml and above in the absence of S9 for the continuous treatment of 24 and 48 hr , respectively and at the dose level of 333 µg/ml in the presence of S9, 3 hours treatment, 24 hours fixation

COMPARISON WITH HISTORICAL CONTROL DATA:
- The number of cells with chromosome aberrations found in the solvent and positive control cultures was within the laboratory historical control data range. Positive control chemicals, mitomycin C and cyclophosphamide induced appropriate responses.

ADDITIONAL INFORMATION ON CYTOTOXICITY:
- Appropriate toxicity was reached at the dose levels selected for scoring.

Any other information on results incl. tables

Although in the second cytogenetic assay in the presence of S9-mix an increase above the historical control data range was observed (gaps excluded), this increase was just above the historical control data range (11 cells with aberrations) and not statistically significant. Therefore this increase was considered not biologically relevant.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

It is concluded that that 4,4’-Isopropylidenediphenol, oligomeric reaction products with 1-chloro-2,3-epoxypropane, reaction products with butan-1-ol and 3-aminomethyl-3,5,5-trimethylcyclohexylamine is not clastogenic in human lymphocytes under the experimental conditions described in the report.

Executive summary:

 

The number of cells with chromosome aberrations found in the solvent control cultures was within the laboratory historical control data range. Positive control chemicals, mitomycin C and cyclophosphamide, both produced a statistically significant increase in the incidence of cells with chromosome aberrations, indicating that the test conditions were adequate and that the metabolic activation system (S9-mix) functioned properly.

 

4,4’-Isopropylidenediphenol, oligomeric reaction products with 1-chloro-2,3-epoxypropane, reaction products with butan-1-ol and 3-aminomethyl-3,5,5-trimethylcyclohexylamine did not induce a statistically significant or biologically relevant increase in the number of cells with chromosome aberrations in the absence and presence of S9-mix, in either of the two independently repeated experiments.

No effects of 4,4’-Isopropylidenediphenol, oligomeric reaction products with 1-chloro-2,3-epoxypropane, reaction products with butan-1-ol and 3-aminomethyl-3,5,5-trimethylcyclohexylamine on the number of polyploid cells and cells with endoreduplicated chromosomes were observed both in the absence and presence of S9-mix. Therefore it can be concluded that the test substance does not disturb mitotic processes and cell cycle progression and does not induce numerical chromosome aberrations under the experimental conditions described in the report.