1-ethylpyrrolidin-2-one

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in mammalian cells

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 476 (In Vitro Mammalian Cell Gene Mutation Test)

GLP compliance:

yes

Type of assay:

mammalian cell gene mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

1-ethylpyrrolidin-2-one

EC Number:

220-250-6

EC Name:

1-ethylpyrrolidin-2-one

Cas Number:

2687-91-4

Molecular formula:

C6H11NO

IUPAC Name:

1-ethylpyrrolidin-2-one

Details on test material:

- Name of test material (as cited in study report): N-Ethyl-2-pyrrolidone
- Analytical purity: 99.8 %
- Lot/batch No.: 29151288P0

Method

Species / strain

Species / strain / cell type:

Chinese hamster Ovary (CHO)

Metabolic activation:

with and without

Metabolic activation system:

S9-mix derived from the livers of rats

Test concentrations with justification for top dose:

Experiment 1:
without S9 mix (4-hour exposure period)
0; 125; 250; 500; 1 000; 1 130 µg/mL
with S9 mix (4-hour exposure period)
0; 125; 250; 500; 1 000; 1 130 µg/mL

Experiment 2:
without S9 mix (24-hour exposure period)
0; 125; 250; 500; 1 000; 1 130 µg/mL
with S9 mix (4-hour exposure period)
0; 400; 600; 800; 1 000; 1 130 µg/mL

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: culture medium (Ham`s F12)

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

other: ethyl methanesulfonate; methylcholanthrene

Details on test system and experimental conditions:

The assay was performed in two independent experiments, using identical procedures, both with and without rat liver microsomal activation.

Evaluation criteria:

A finding is assessed as positive if the following criteria are met:
Increase of the corrected mutation frequencies (MFcorr.) both above the concurrent negative control values and our historical negative control data range (see Appendix 5).
Evidence of reproducibility of any increase in mutant frequencies.
A statistically significant increase in mutant frequencies and the evidence of a dose-response relationship.
The test substance is considered non-mutagenic according to the following criteria:
The corrected mutation frequency (MFcorr.) in the dose groups is not statistically significant increased above the concurrent negative control and is within our historical negative control data range.

Statistics:

Due to the clearly negative findings, a statistical evaluation was not carried out.

Results and discussion

Test results

Species / strain:

Chinese hamster Ovary (CHO)

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Positive controls validity:

valid

Additional information on results:

According to the results of the present in vitro study, the test substance N-Ethyl-2-pyrrolidone did not lead to an increase in the number of mutant colonies either without S9 mix or after the addition of a metabolizing system in two experiments performed independently of each other. The mutant frequencies at any concentration were close to or within the range of that of the concurrent negative control values and within the range of our historical negative control data.
The mutation frequencies of the negative control groups were within our historical negative control data range including all vehicles used in our laboratory and, thus, fulfilled the acceptance criteria of this study.
The increase in the frequencies of mutant colonies induced by the positive control substances EMS and MCA clearly demonstrated the sensitivity of the test method and of the metabolic activity of the S9 mix employed. The values were within the range of the historical positive control data and, thus, fulfilled the acceptance criteria of this study.
Cytotoxicity: In both experiments in teh absence and the presence of S9 mix, no cytotoxicity indicated by reduced relative cloning efficiency of below 20 % relative survival was observed.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Exp.	Exposure period	Test groups	S9 mix	Prec.*	Genotoxicity** MFcorr. [per 10^6cells]	Cytotoxixity***
						CE1[%]	CE2[%]
1	4 hours	Negative control	-	-	3.97	100.0	100.0
		125 µg/ml	-	-	7.52	105.6	990.
		500 µg/ml	-	-	2.17	79.4	92.5
		500 µg/ml	-	-	4.61	72.1	92.5
		1000 µg/ml	-	-	0.71	90.9	95.2
		1130 µg/ml	-	-	2.20	83.1	90.9
		Positive control^1	-	-	62.43	80.7	92.2
2	24 hours	Negative control	-	-	0.56	100.0	100.0
		125 µg/ml	-	-	0.00	101.0	83.5
		500 µg/ml	-	-	2.23	84.7	94.0
		500 µg/ml	-	-	2.45	94.8	98.6
		1000 µg/ml	-	-	3.55	87.2	88.7
		1130 µg/ml	-	-	1.44	81.3	99.1
		Positive control^1	-	-	297.48	73.6	65.6
1	4 hours	Negative control	+	-	1.27	100.0	100.0
		125 µg/ml	+	-	3.60	101.2	95.3
		500 µg/ml	+	-	0.61	91.2	104.7
		500 µg/ml	+	-	1.64	81.5	97.8
		1000 µg/ml	+	-	2.46	90.8	102.5
		1130 µg/ml	+	-	0.88	92.3	103.6
		Positive control^2	+	-	44.37	88.6	100.3
2	4 hours	Negative control	+	-	1.02	100.0	100.0
		125 µg/ml	+	-	0.27	110.2	92.3
		500 µg/ml	+	-	0.00	113.2	93.0
		500 µg/ml	+	-	2.61	113.5	97.3
		1000 µg/ml	+	-	3.23	109.1	89.2
		1130 µg/ml	+	-	3.12	104.1	90.9
		Positive control^2	+	-	40.16	104.3	78.3

*Precipitation in culture medium at the end of exposure period

** Mutant frequency MF_corr.: number of mutant colonies oper 10⁶cells corrected with the CE2 value

*** Cloning efficiency related to the respective negative control

¹300 µg/ml                                            ²MCA 10 µg/ml

Applicant's summary and conclusion

Conclusions:

Thus, under the experimental conditions chosen here, the conclusion is drawn that N-Ethyl-2-pyrrolidone is not mutagenic under in vitro conditions in the HPRT locus assay using CHO cells in the absence and the presence of metabolic activation.