2,4,7,9-tetramethyldec-5-yne-4,7-diol

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:

1999

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: according to EC Directive 92/69/EEC and Regulation EC/440/2008 guideline methods under GLP conditions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1999

Report date:

1999

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)

GLP compliance:

yes

Type of assay:

in vitro mammalian chromosome aberration test

Test material

Test material information

Constituent 1

Reference substance name:

2,4,7,9-tetramethyldec-5-yne-4,7-diol

EC Number:

204-809-1

EC Name:

2,4,7,9-tetramethyldec-5-yne-4,7-diol

Cas Number:

126-86-3

Molecular formula:

C14 H26 O2

IUPAC Name:

2,4,7,9-tetramethyldec-5-yne-4,7-diol

Details on test material:

Lot# 23058
Purity: 98,7 %

Method

Species / strain

Species / strain / cell type:

Chinese hamster Ovary (CHO)

Metabolic activation:

with and without

Test concentrations with justification for top dose:

19.5, 39.1, 78.1-78.3, 156.3, 312.5, 1250, and 3500 ug/ml

Vehicle / solvent:

DMSO

Results and discussion

Test results

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: 312.5

Remarks on result:

other: other: CHO Cells

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

RS-Freetext:
In the cytotoxicity experiment, all of the cultures from the
top two dose levels exhibited a significant decrease in
confluency (0 to 25 percent) and therefore were not
harvested. For cultures exposed to the test article for 3 hr
in the presence or absence of MA, no significant reduction
in mitotic index was observed at dose levels of 312.5 ug/mL
and below. Cultures exposed for 21 hr to the test article at
312.5 ug/mL showed a significant reduction in mitotic index.
In the initial chromosome aberration experiment,
cytotoxicity was evident in cultures exposed to 312.5 ug/mL
under both MA conditions, so the cells were not harvested
for evaluation.

In both the initial chromosome aberration experiment and in
the replicate experiment, there was no statistically
significant increase in the number of cells with structural
aberrations at the three dose levels scored in both MA
conditions (39.1, 78.1, and 156.3 ug/mL).  The mitotic index
was comparable to that for the control and no increases in
polyploidy were observed in the presence or absence of MA.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

This study was performed to evaluate the ability of 2,4,7,9-tetramethyl-5-decyne-4,7-diol to induce chromosome aberrations in Chinese hamster ovary (CHO) cells in the presence and absence of rat S-9 metabolic activation (MA).

In the cytotoxicity assay, CHO cells were exposed to 2,4,7,9-tetramethyl-5-decyne-4,7-diol at concentrations of 19.5, 78.3, 312.5, 1250, and 3500 ug/ul in both the absence and presence of MA. A high dose of 3500 ug/ul was used based on the limit of solubility of the test article in dimethylsulfoxide (DMSO). Cells were exposed to the test article in the absence of MA for 3 and 21 hr and in the presence of MA for 3 hr. At 21 hr after exposure initiation, cells were harvested and evaluated. All of the cultures from the top two dose levels exhibited a significant decrease in confluency (0 to 25 percent) and therefore were not harvested. For cultures exposed to the test article for 3 hr in the presence or absence of MA, no significant reduction in mitotic index was observed at dose levels of 312.5 ug/ul and below. Cultures exposed for 21 hr to the test article at 312.5 ug/ul showed a significant reduction in mitotic index.

Based on the cytotoxicity results, the initial chromosome aberration study was performed by exposing CHO cells for 3 hr to 2,4,7,9-tetramethyl-5-decyne-4,7-diol at concentrations of 19.5, 39.1, 78.1, 156.3, and 312.5 ug/ul in both the absence and presence of MA. At 21 hr after initiation of exposure, cells were harvested and evaluated. Cytotoxicity was evident in cultures exposed to 312.5 ug/ul under both MA conditions, so the cells were not harvested for evaluation. In cultures at the three dose levels scored in both MA conditions (39.1, 78.1, and 156.3 ug/ul), there was no statistically significant increase in the number of cells with structural aberrations and the mitotic index was comparable to that for the control. No increases in polyploidy were observed in the presence or absence of MA.

The dose levels for the replicate experiment were based on the results of the cytotoxicity experiment (-MA) and the initial experiment (+MA) which indicated cytotoxicity and a significant reduction in confluency at the 312.5 ug/ul dose level. The replicate experiment was performed by exposing CHO cells for 21 hr to the test article at concentrations of 9.8, 19.5, 39.1, 78.1, and 156.3 ug/ul in the absence of MA and for 3 hr at concentrations of 19.5, 39.1, 78.1, and 156.3 ug/ul in the presence of MA. At 21 hr after initiation of exposure, cells were harvested and evaluated. At the three dose levels scored in both MA conditions (39.1, 78.1, and 156.3 ug/ul), there was no statistically significant increase in the number of cells with structural aberrations and the mitotic index was comparable to that for the control. No increases in polyploidy were observed in the presence or absence of MA.

Executive summary:

This study was performed to evaluate the ability of 2,4,7,9-tetramethyl-5-decyne-4,7-diol to induce chromosome aberrations in Chinese hamster ovary (CHO) cells in the presence and absence of rat S-9 metabolic activation (MA). In the cytotoxicity assay, CHO cells were exposed to 2,4,7,9-tetramethyl-5-decyne-4,7-diol at concentrations of 19.5, 78.3, 312.5, 1250, and 3500 ug/ul in both the absence and presence of MA. A high dose of 3500 ug/ul was used based on the limit of solubility of the test article in dimethylsulfoxide (DMSO). Cells were exposed to the test article in the absence of MA for 3 and 21 hr and in the presence of MA for 3 hr. At 21 hr after exposure initiation, cells were harvested and evaluated. All of the cultures from the top two dose levels exhibited a significant decrease in confluency (0 to 25 percent) and therefore were not harvested. For cultures exposed to the test article for 3 hr in the presence or absence of MA, no significant reduction in mitotic index was observed at dose levels of 312.5 ug/ul and below. Cultures exposed for 21 hr to the test article at 312.5 ug/ul showed a significant reduction in mitotic index. Based on the cytotoxicity results, the initial chromosome aberration study was performed by exposing CHO cells for 3 hr to 2,4,7,9-tetramethyl-5-decyne-4,7-diol at concentrations of 19.5, 39.1, 78.1, 156.3, and 312.5 ug/ul in both the absence and presence of MA. At 21 hr after initiation of exposure, cells were harvested and evaluated. Cytotoxicity was evident in cultures exposed to 312.5 ug/ul under both MA conditions, so the cells were not harvested for evaluation. In cultures at the three dose levels scored in both MA conditions (39.1, 78.1, and 156.3 ug/ul), there was no statistically significant increase in the number of cells with structural aberrations and the mitotic index was comparable to that for the control. No increases in polyploidy were observed in the presence or absence of MA. The dose levels for the replicate experiment were based on the results of the cytotoxicity experiment (-MA) and the initial experiment (+MA) which indicated cytotoxicity and a significant reduction in confluency at the 312.5 ug/ul dose level. The replicate experiment was performed by exposing CHO cells for 21 hr to the test article at concentrations of 9.8, 19.5, 39.1, 78.1, and 156.3 ug/ul in the absence of MA and for 3 hr at concentrations of 19.5, 39.1, 78.1, and 156.3 ug/ul in the presence of MA. At 21 hr after initiation of exposure, cells were harvested and evaluated. At the three dose levels scored in both MA conditions (39.1, 78.1, and 156.3 ug/ul), there was no statistically significant increase in the number of cells with structural aberrations and the mitotic index was comparable to that for the control. No increases in polyploidy were observed in the presence or absence of MA.