2'-acetonaphthone

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro cytogenicity / chromosome aberration study in mammalian cells

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data is from J-check

Data source

Reference

Reference Type:

review article or handbook

Title:

In vitro mammalian chromosome aberration test for CAS no 2173-57-1

Author:

National Institute of Technology and Evaluation

Year:

2017

Bibliographic source:

Japan Chemicals Collaborative Knowledge Database, 2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)

Principles of method if other than guideline:

In vitro mammalian chromosome aberration test was performed to determine the mutagenic nature of 2-(2-methylpropoxy)naphthalene

GLP compliance:

not specified

Type of assay:

other: In vitro mammalian chromosome aberration test

Test material

Test material information

Constituent 1

Reference substance name:

Isobutyl 2-naphthyl ether

EC Number:

218-529-2

EC Name:

Isobutyl 2-naphthyl ether

Cas Number:

2173-57-1

Molecular formula:

C14H16O

IUPAC Name:

2-isobutoxynaphthalene

Details on test material:

- Name of test material: 2-(2-Methylpropoxy)Naphthalene
- Molecular formula: C14H16O
- Molecular weight: 200.279 g/mol
- Substance type: Organic
- Physical state: No data
- Purity: No data
- Impurities (identity and concentrations): No data

Specific details on test material used for the study:

- Name of test material: 2-(2-Methylpropoxy)Naphthalene
- Molecular formula: C14H16O
- Molecular weight: 200.279 g/mol
- Substance type: Organic
- Physical state: No data
- Purity: No data
- Impurities (identity and concentrations): No data

Method

Target gene:

No data

Species / strain

Species / strain 1

Species / strain / cell type:

mammalian cell line, other: Chinese hamster lung (CHL/IU) cells

Remarks:

Short term treatment

Details on mammalian cell type (if applicable):

No data

Additional strain / cell type characteristics:

not specified

Species / strain 2

Species / strain / cell type:

mammalian cell line, other: Chinese hamster lung (CHL/IU) cells

Remarks:

Continuous treatmnet

Details on mammalian cell type (if applicable):

No data

Additional strain / cell type characteristics:

not specified

Cytokinesis block (if used):

No data

Metabolic activation:

with and without

Metabolic activation system:

No data

Test concentrations with justification for top dose:

Continuous treatment: 0, 61.4, 76.8, 96.0 and 120 µg/mL
Short term treatment: 0, 76.8, 96.0 and 120 µg/mL without S9 mix and at 0, 16.1, 20.1 and 25.2 µg/mL with S9 mix

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: The test chemical was soluble in DMSO

Controls

Untreated negative controls:

not specified

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

cyclophosphamide

mitomycin C

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium

DURATION
- Preincubation period: 3 days
- Exposure duration:
Short term treatment: 6 hrs
Continuous treatment: 24 hrs
- Expression time (cells in growth medium):
Short term treatment: 6 hrs
Continuous treatment: 24 hrs
- Selection time (if incubation with a selection agent): No data
- Fixation time (start of exposure up to fixation or harvest of cells): No data

SELECTION AGENT (mutation assays): No data
SPINDLE INHIBITOR (cytogenetic assays): No data
STAIN (for cytogenetic assays): No data

NUMBER OF REPLICATIONS: No data

NUMBER OF CELLS EVALUATED: 200 metaphase cells/dose (100/plate) for structural aberrations (i.e. gap, ctb, csb, cte, cse and other abnormalities) and for polyploid

DETERMINATION OF CYTOTOXICITY
- Method: mitotic index; cloning efficiency; relative total growth; other: yes, cytotoxicity was measured as inhibition of cell growth

OTHER EXAMINATIONS:
- Determination of polyploidy: Yes
- Determination of endoreplication: No data
- Other: No data

OTHER: No data

Rationale for test conditions:

No data

Evaluation criteria:

The final result of each test was decided for structural aberrations or polyploid cells, separately as follows:negative (-): if the frequency of aberrant cells was less than 5%,inconclusive (±): in greater than 5% but less than 10%,and positive (+): if 10% or more.

Statistics:

No data

Results and discussion

Test results

Test results 1

Species / strain:

mammalian cell line, other: Chinese hamster lung (CHL/IU) cells

Remarks:

Short term treatment

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

cytotoxicity (more than 50% inhibition of cell growth) was shown at 120 µg/mL and above under the absence of metabolic activation and at 25.2 µg/mL and above under the presence of metabolic activation.

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

Positive controls validity:

valid

Test results 2

Species / strain:

mammalian cell line, other: Chinese hamster lung (CHL/IU) cells

Remarks:

Long term treatment

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

cytotoxicity (more than 50% inhibition of cell growth) was shown at 120 µg/mL and above under the absence of metabolic activation and at 25.2 µg/mL and above under the presence of metabolic activation.

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

Positive controls validity:

valid

Additional information on results:

No data

Remarks on result:

other: No mutagenic potential

Any other information on results incl. tables

Table: Historical control data

Historical control values of structural aberrations
Group	Test system	N	Incidence of structural aberration (%) [Mean±SD]	Range
				Lower	Upper
Negative control	Short term treatment (-S9)	157	0.6±0.8	0.0	2.9*
	Short term treatment (+S9)	166	0.4±0.6	0.0	2.3*
	Continuous treatment (24 hrs)	135	0.6±0.7	0.0	2.8*
Positive control	Short term treatment (-S9)	157	39.0±9.7	10.0	68.2*
	Short term treatment (+S9)	164	29.2±10.5	10.0	60.8*
	Continuous treatment (24 hrs)	133	30.3±8.2	10.0	54.9*

 

Historical control values of polyploidy cells
Group	Test system	N	Incidence of structural aberration (%) [Mean±SD]	Range
				Lower	Upper
Negative control	Short term treatment (-S9)	157	0.3±0.5	0.0	1.9*
	Short term treatment (+S9)	166	0.2±0.5	0.0	1.7*
	Continuous treatment (24 hrs)	135	0.4±0.7	0.0	2.4*

 

* The range is calculated by Mean±3 X SD

 

Table: Results of growth inhibition test (Short term treatment)

Compound	Dose (µg/mL)	Relative cell growth (%)		Mean
		-S9	+S9	-S9	+S9
DMSO	0	100.0	100.0	100.0	100.0
		100.0	100.0
2- Napthylisobutyl ether	15.6	100.0	103.9	100.5	101.0
		100.8	98.0
	31.3	91.1	31.4	86.5	21.7
		97.2	20.4
	62.6	89.7	22.9	86.5	21.7
		83.3	20.4
	125	28.3	15.9	22.7	16.0
		17.1	16.0
	250d	7.5	6.6	6.3	10.1
		5.1	13.6
	501d	6.0	6.1	6.7	6.1
		7.3	6.1
	1002d	12.9	11.1	12.5	11.0
		12.0	10.8
	2003d	6.6	10.7	5.5	9.2
		4.4	7.6

d: visible precipitation was noted

Table 2. Chromosome aberration test
[Short-term treatment : -S9]
Compound Dose	Time of exposure	Relative cell growth	No. of cells analyzed	No. of cells with structural aberrations						No. of cells with aberrations	No. of cells analyzed for polyploid	No. of polyploid cells
(μg/mL)	(h)	(%)		gap	ctb	cte	csb	cse	oth	-gap(%)		(%)
DMSO a) 0	6	100	200	0	1	0	0	0	0	1 ( 0.5)	200	0 ( 0.0)
2-Naphthylisobutyl ether
76.8	6	77.2	200	0	0	0	0	0	0	0 ( 0.0)	200	0 ( 0.0)
96	6	53.5	200	0	2	1	0	0	0	3 ( 1.5)	200	0 ( 0.0)
120	6	24.1	200	0	2	4	0	0	0	5 ( 2.5)	200	1 ( 0.5)
150	6	11	NA
MMC b) 0.1	6	85.6	200	2	30	69	0	1	0	88 (44.0)	200	0 ( 0.0)
Abbreviation: ctb; chromatid break, cte: chromatid exchange, csb: chromosome break, cse: chromosome exchange, oth: others
gap: total No. of cells with aberrations except gap
NA：Not analyzed
a): Negative control (Dimethyl sulfoxide, 10 μL/mL)
b): Positive control:Mitomycin C
[Short-term treatment : +S9]
Compound Dose	Time of exposure	Relative cell growth	No. of cells analyzed	No. of cells with structural aberrations						No. of cells with aberrations	No. of cells analyzed for polyploid	No. of polyploid cells
(μg/mL)	(h)	(%)		gap	ctb	cte	csb	cse	oth	-gap(%)		(%)
DMSO a) 0	6	100	200	0	0	0	0	0	0	0 ( 0.0)	200	1 ( 0.5)
2-Naphthylisobutyl ether
16.1	6	64.3	200	0	0	0	0	0	0	0 ( 0.0)	200	1 ( 0.5)
20.1	6	56.2	200	0	0	0	0	0	0	0 ( 0.0)	200	0 ( 0.0)
25.2	6	40.2	200	0	1	2	0	0	0	3 ( 1.5)	200	2 ( 1.0)
31.5	6	14.6	NA
CP b) 12.5	6	88	200	3	8	28	0	0	0	34 (17.0)	200	0 ( 0.0)
Abbreviation: ctb; chromatid break, cte: chromatid exchange, csb: chromosome break, cse: chromosome exchange, oth: others
gap: total No. of cells with aberrations except gap
NA：Not analyzed
a): Negative control (Dimethyl sulfoxide, 10 μL/mL)
b): Positive control: Cyclophosphamide
[Continuous treatment : 24 h]
Compound Dose	Time of exposure	Relative cell growth	No. of cells analyzed	No. of cells with structural aberrations						No. of cells with aberrations	No. of cells analyzed for polyploid	No. of polyploid cells
(μg/mL)	(h)	(%)		gap	ctb	cte	csb	cse	oth	-gap(%)		(%)
DMSO a) 0	24	100	200	1	1	0	0	0	0	1 ( 0.5)	200	1 ( 0.5)
2-Naphthylisobutyl ether
61.4	24	72.5	200	0	2	0	0	0	0	2 ( 1.0)	200	0 ( 0.0)
76.8	24	83	200	1	1	0	0	0	0	1 ( 0.5)	200	0 ( 0.0)
96	24	66.5	200	1	2	0	0	0	0	2 ( 1.0)	200	0 ( 0.0)
120	24	40.3	182	2	3	1	0	0	0	4 ( 2.2)	200	0 ( 0.0)
150	24	26.3	Toxic
MMC b) 0.05	24	123.1	200	5	33	68	0	0	0	84 (42.0)	200	1 ( 0.5)
Abbreviation: ctb; chromatid break, cte: chromatid exchange, csb: chromosome break, cse: chromosome exchange, oth: others
gap: total No. of cells with aberrations except gap
a): Negative control (Dimethyl sulfoxide, 10 μL/mL)
b): Positive control: Mitomycin C

Applicant's summary and conclusion

Conclusions:

2-(2-Methylpropoxy)Naphthalene did not induce chromosome aberration in Chinese hamster lung (CHL/IU) cells in the short term treatment (with and without) and continuous treatment (without) and hence it is not likely to classify as a gene mutant in vitro.

Executive summary:

In vitro mammalian chromosome aberration test was performed to determine the mutagenic nature of the test chemical using Chinese hamster lung cells (CHL/IU). The test chemical was dissolved in DMSO and used at dose levels of 0, 76.8, 96.0 and 120µg/mL without S9 mix and at 0, 16.1, 20.1 and 25.2µg/mL with S9 mix for the short-term treatment, and at 0, 61.4, 76.8, 96.0 and 120µg/mL for continuous treatment. In either test condition, no increase in structural aberrations or polyploidy was observed, although cytotoxicity (more than 50% inhibition of cell growth) was shown at 120µg/mL and above under the absence of metabolic activation and at 25.2µg/mL and above under the presence of metabolic activation. The positive controls were effective for induction of chromosome aberrations. The test chemical did not induce chromosome aberration in Chinese hamster lung (CHL/IU) cells in the short term treatment (with and without) and continuous treatment (without) and hence it is not likely to classify as a gene mutant in vitro.