2-isobutyl-4-vinyl-1,3-dioxolane

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vitro

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

from 2017-04-25 to 2017-07-12

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 442D (In Vitro Skin Sensitisation: ARE-Nrf2 Luciferase Test Method)

Version / remarks:

2015-02-04

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

activation of keratinocytes

Justification for non-LLNA method:

Replacement method for animals testing.

Test material

Test material information

Constituent 1

Reference substance name:

2-isobutyl-4-vinyl-1,3-dioxolane

EC Number:

815-031-2

Cas Number:

1411949-02-4

Molecular formula:

C9H19O2

IUPAC Name:

2-isobutyl-4-vinyl-1,3-dioxolane

Test material form:

liquid

In vitro test system

Details on the study design:

Skin sensitisation (In vitro test system) - Details on study design: The in vitro KeratinoSens™ assay enables detection of the sensitising potential of a test item by addressing the second molecular key event of the adverse outcome pathway (AOP), namely activation of keratinocytes, by quantifying the luciferase activity in the transgenic cell line KeratinoSens™. The luciferase activity, assessed by luminescence measurement, compared to the respective solvent controls is used to support discrimination between skin sensitisers and non-sensitisers.

Results and discussion

Positive control results:

Experiment 1: 32 µM, 1.91 (SD 0.45) fold induction; 64 µM, 3.26 (SD 0.79) fold Induction
Experiment 2: 32 µM, 1.76 (SD 0.21) fold induction; 64 µM, 2.81 (SD 0.64) fold Induction

In vitro / in chemico

Results

Results 1

Key result

Run / experiment:

other: test substance concentration 2000 µM

Parameter:

other: max. Luciferase activity induction (Imax)

Value:

1.24

Vehicle controls validity:

valid

Negative controls validity:

not examined

Positive controls validity:

valid

Results 2

Key result

Run / experiment:

other: test substance concentration 2000 µM

Parameter:

other: Cell viability (%)

Value:

86.3

Vehicle controls validity:

valid

Negative controls validity:

not examined

Positive controls validity:

valid

Results 3

Key result

Run / experiment:

other: test substance concentration 2000 µM

Parameter:

other: EC 1.5

Vehicle controls validity:

valid

Negative controls validity:

not examined

Positive controls validity:

valid

Remarks on result:

not determinable

Other effects / acceptance of results:

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for solvent control: Yes
- Acceptance criteria met for positive control: Yes
- Acceptance criteria met for variability between replicate measurements: Yes

Any other information on results incl. tables

Induction of Luciferase Activity - Overall Induction:

	Concentration [µM]	Fold Induction
		Experiment 1	Experiment 2	Mean	SD
Solvent Control	-	1.00	1.00	1.00	0.00
Positive Control	4.00	1.10	1.10	1.10	0.00
	8.00	1.15	1.34	1.24	0.13
	16.00	1.39	1.35	1.37	0.03
	32.00	1.61	1.91	1.76	0.21
	64.00	2.36	3.26	2.81	0.64
Test Substance	0.98	1.06	0.91	0.99	0.11
	1.95	1.01	1.10	1.06	0.07
	3.91	0.97	1.04	1.00	0.05
	7.81	1.03	1.08	1.06	0.04
	15.63	1.03	0.80	0.91	0.17
	31.25	1.06	0.91	0.98	0.11
	62.50	0.93	0.87	0.90	0.05
	125.00	1.14	0.88	1.01	0.19
	250.00	1.11	0.98	1.05	0.10
	500.00	1.10	0.97	1.03	0.09
	1000.00	1.17	0.96	1.06	0.15
	2000.00	1.24	1.07	1.15	0.12

Acceptance Criteria:

Criterion	Range	Experiment 1	Pass/Fail	Experiment2	Pass/Fail
CV Solvent Control	< 20 %	7.0	Pass	17.8	Pass
No. of positive control concentration steps with significant luciferase activity induction > 1.5	≥1	2.0	Pass	2.0	Pass
EC1.5 PC	7 < x < 34 µM	23.95	Pass	20.35	Pass
Induction PC at 64 µM	2.99 < x < 8.00	2.36	Pass	3.26	Pass

Applicant's summary and conclusion

Interpretation of results:

other: Under the condition of this study the test substance did not induce the luciferase activity and is threrefore considered as non sensitiser.

Remarks:

The data generated with this method may be not sufficient to conclude on the absence of skin sensitisation potential of chemicals and should be considered in the context of integrated approach such as IATA.

Conclusions:

In an in vitro ARE-Nrf2 Luciferase assay (KeratinoSens™) according to OECD Guideline 442D, the test substance did not induce luciferase activity and no EC1.5 could be determined and is threrefore considered as non sensitiser.

Executive summary:

In the present study, the skin sensitising properties of 2-isobutyl-4-vinyl-1,3-dioxolane were determined in an in vitro ARE-Nrf2 Luciferase assay (KeratinoSens™) according to OECD Guideline 442D.

Based on a molecular weight of 156.22 g/mol a stock solution of 200 mM was prepared in water. Based on the stock solution a set of eleven master solutions in 100 % solvent was prepared by serial dilution using a constant dilution factor of 1:2. These master solutions were diluted 1:100 in cell culture medium. The following concentration range was tested in the assay: 2000, 1000, 500, 250, 125, 62.5, 31.25, 15.63, 7.81, 3.91, 1.95, 0.98 µM.

Cells were incubated with the test item for 48 h at 37 °C. After exposure cells were lysed and luciferase activity was assessed by luminescence measurement. In the first experiment, a max luciferase activity (Imax) induction of 1.24 was determined at a test item concentration of 2000 µM. The corresponding cell viability was 86.3 %. No significant luciferase induction >1.5 was found in the tested concentration range. Therefore, no EC1.5 value could be calculated. Furthermore, no cytotoxic effect was observed. In the second experiment, a max luciferase activity (Imax) induction of 1.1 was determined at a test item concentration of 1.95 µM. The corresponding cell viability was 119.5 %. No significant luciferase induction >1.5 was found in the tested concentration range. Therefore, no EC1.5 value could be calculated. Within the second experiment a cytotoxic effect was observed starting from 125 µM onward. No dose response for luciferase activity induction was observed for each individual run as well as for an overall luciferase activity induction. Under the condition of this study the test substance is therefore considered as non sensitiser.