Fatty acids, C18-unsatd., dimers, ethoxylated

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vitro

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

04 Dec 2012 - 05 Feb 2013

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Performed according to GLP but no OECD guideline available yet.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Materials and methods

Principles of method if other than guideline:

In-vitro system for activation of antioxidant-response-element dependent genes in keratinocytes. The endpoint measurement is the up-regulation of the luciferase activity after 48 hours incubation with test substance. This up-regulation is an indicator for the activation of the Keap1/Nrf2/ARE signaling pathway.
Bauch C, Kolle SN, Ramirez T, Eltze T, Fabian E, Mehling A, Teubner W, van Ravenzwaay B, Landsiedel R, (2012), Putting the parts together: Combining in vitro methods to test for skin sensitizing potentials, Regul Toxicol Pharmacol, 63(3):489-504.

GLP compliance:

yes (incl. QA statement)

Remarks:

BASF SE, Experimental Toxicology and Ecology, Ludwigshafen, Germany

Type of study:

other: part of combined in vitro sensization battery

Test material

Test material information

Constituent 1

Reference substance name:

Fatty acids, C18-unsatd., dimers, ethoxylated

EC Number:

614-587-1

Cas Number:

68551-92-8

Molecular formula:

Unspecified

IUPAC Name:

Fatty acids, C18-unsatd., dimers, ethoxylated

Details on test material:

- Name of test material (as cited in study report): Fatty acids, C18-unsatd., dimers, ethoxylated (NIO AD1)
- Analytical purity: ~ 94%
- Lot/batch No.: 0007876143

In vivo test system

Test animals

Species:

other: keratinocyte cell line

Study design: in vivo (non-LLNA)

Positive control substance(s):

yes

Remarks:

Ethylene glycol dimethacrylate (EGDMA 18 µg/mL)

Results and discussion

Positive control results:

The positive control EGDMA activated the luciferase reporter 4.7a and 5.24 fold in 2 independent experiments.

Any other information on results incl. tables

Table 1: Summary of LuSens Results

	2^ndexperiment		3^rdexperiment
Concentration [µg/mL]	Fold induction	Rel. viability	Fold induction	Rel. viability
VC	1.00	100.0	1.0	100.0
558*	n.d.	n.d.	1.42	80.
670*	n.d.	n.d.	1.14	76.2
804*	1.65	71.2	1.21	76.4
965*	1.67	69.7	1.29	83.1
1157*	1.43	66.5	1.22	84.9
1389*	1.36	69.8	1.01	87.6
1667*	1.06	70.5	n.d.	n.d.
2000*	0.87	79.5	n.d.	n.d.
EGDMA	4.71	87.6	5.24	103.5
LA	1.10	96.8	0.74	105.8

* Precipitation of test substance after 48 h incubation

n.d. = not determined

EGDMA = Ethylene glycol dimethacrylate (EGDMA 18 μg/mL)

LA = DL-Lactic acid (LA 450 µg/mL)

Applicant's summary and conclusion

Conclusions:

Based on the observed results it was concluded that Fatty acids, C18-unsatd., dimers, ethoxylated (NIO AD1) does not induce luciferase activity in LuSens cells under the test conditions chosen.

Executive summary:

The keratinocyte activating potential of test substance Fatty acids, C18-unsatd., dimers, ethoxylated (NIO AD1) was evaluated in the LuSens assay. For this purpose the test substance was incubated with a luciferase reporter cell line (LuSens cells) for ca. 48 hours at 37°C and ARE-dependent luciferase activity was measured in a luminometer. The test substance was soluble in 1% DMSO at a concentration of 2000 μg/mL. In order to determine the concentrations suitable for the main experiment a pre-test (experimental conduct in accordance with GLP but without a GLP status) was performed. Cells were exposed to 9 concentrations of the test substance (0.5 μg/mL up to 2000 μg/mL) and cytotoxicity was determined thereafter by MTT assay. No decrease in cell viability below 70% was observed. In the main test, test substance was used at eight final concentrations. After 48 hour exposure luciferase activity was measured in a luminometer. The test substance was concluded to exhibit a keratinocyte activating potential when the luciferase activity exceeded 1.5 fold induction with respect to the vehicle control and at concentrations that did not reduce a viability below 70%. In parallel a MTT assay was performed to assess cytotoxicity of the test substance. The LuSens showed the following results: The test substance was soluble in DMSO. The dilutions of the test substance were solutions in DMSO and suspensions in culture medium at a concentration of 558 μg/mL onward. However, after 48 hours precipitates were noticed in the samples. In summary, after 48 hours of exposure to test substance Fatty acids, C18-unsatd., dimers, ethoxylated (NIO AD1) luciferase activity in LuSens cells was was not induced at concentration affording at least 70% viability. From this it has to be concluded that Fatty acids, C18-unsatd., dimers, ethoxylated (NIO AD1) does not have a keratinocyte activating potential.