Disodium 1,5-dihydroxypentane-1,5-disulphonate

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vitro

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 19 SEP 2017 to 21 DEC 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2018

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

other: "LuSens Test" on the basis of OECD Guideline 442D

Version / remarks:

The LuSens test is an ARE Reporter Gene Assay that was developed by the BASF SE (Ludwigshafen, Germany) and is only based on the OECD 442D Guideline.

Deviations:

no

Remarks:

Principles of method if other than guideline:

The deviations from the OECD 442D are given below:
1. For the test the LuSens cell line was used. This cell line was developed by the BASF SE.
2. In order to determine the concentration range applicable for experiment I and II a Cytotoxicity Range Finder Test (CRFT) was performed. This test was performed in accordance to the protocol of the BASF SE.
3. The dilution factor in the experiments is 1.2fold.
4. The controls are tested at only one concentration.
5. As positive control EGDMA (Ethylene glycol dimethylacrylate) was used.
6. During the experimental performance the luciferase induction is measured at a second 96-well plate in accordance to the protocol of the BASF SE.
7. Regarding the acceptance criteria, the positive control must induce a luciferase induction of a minimum of 2.5fold in comparison to the solvent control. In addition the viability must be ≥ 70 %. The negative control must induce a luciferase induction of <1.5 fold and a viability of ≥ 70 %. Regarding the test item, a minimum of 3 test item concentrations has to be analysable (viability: ≥ 70 %).

Prior to routine use, the validity of the LuSens test at LAUS GmbH was demonstrated in a proficiency study. In this study, 22 proficiency chemicals (indicated by the OECD 442D guideline as well as the OECD PERFORMANCE STANDARDS FOR ASSESSMENT OF PROPOSED SIMILAR OR MODIFIED IN VITRO SKIN SENSITISATION ARE-NRF2 LUCIFERASE TEST METHODS) were tested. As prescribed by the guidelines, more than 80 % (96 %) of the results were correctly categorized. Therefore, the proficiency of the LuSens test was demonstrated. For this reason, all deviations of the LuSens test in comparison to the OECD 442D are declared as uncritical. The end result is not affected by those changes.

For the positive control p-Phenylenediamine no historical data are available. The deviation is considered as uncritical since the solvent controls prescribed by the OECD 442 D and the protocol of the BASF SE are not soluble in aquatic solvents at the required concentration. p-Phenylenediamine is also one of the proficiency chemicals and therefore accepted as a skin sensitizer according to the OECD. Furthermore the positive result of the substance in this study demonstrates the sensitivity and validity of the study.

GLP compliance:

yes (incl. QA statement)

Type of study:

activation of keratinocytes

Test material

Test material information

Constituent 1

Reference substance name:

Disodium 1,5-dihydroxypentane-1,5-disulphonate

Cas Number:

7420-89-5

Molecular formula:

C5H10Na2O8S2

IUPAC Name:

Disodium 1,5-dihydroxypentane-1,5-disulphonate

impurity 1

Reference substance name:

Sodium sulfate

Cas Number:

7757-82-6

IUPAC Name:

Sodium sulfate

impurity 2

Reference substance name:

Sodium hydrogen sulfite

Cas Number:

7631-90-5

IUPAC Name:

Sodium hydrogen sulfite

In vitro test system

Details on the study design:

The LuSens cell line was specially designed for this test system by the BASF SE (Ludwigshafen, Germany). It employs the use of a reporter gene for luciferase placed under the control of the antioxidant response element (ARE) and hence monitors Nrf-2 transcription factor activity. For designing this cell line, a human keratinocyte cell line (provided by RWTH, Aachen, Germany) was transfected with the pGL4.20 [luc2/Puro] vector (Promega, Germany) carrying the regulatory antioxidant response element (ARE) upstream of the luciferase gene (Luc2, Promega, Germany) at the Institute of Anatomy and Cell Biology of the RWTH, Aachen (laboratory of PD Dr. Wruck).

Results and discussion

Positive control results:

p-Phenylenediamine (80 µM) was used as positive control. The viability was above 70 % and a distinct increase in luciferase induction above 2.5 fold in comparison to the solvent control was detected.

In vitro / in chemico

Results

Run / experiment:

other: 2 independent experiments. The exposure time was 48 h. Test item concentrations showed a viability ≥ 70 % and be evaluated for luciferase induction: Experiment I: 135 µM up to 694 µM Experiment II: 135 µM up to 402 µM

Parameter:

other: Viability (%)

Value:

70

Negative controls validity:

valid

Remarks:

DL-lactic acid (5000 µM) was used as negative control. The viability was above 70 %

Positive controls validity:

valid

Remarks:

p-Phenylenediamine (80 µM) was used as positive control. The viability was above 70 %

Applicant's summary and conclusion

Conclusions:

In conclusion, it can be stated that under the experimental conditions of this study, the test item, Glutardialdehyde bis-Sodiumbisulfite, was positive in the LuSens assay and is therefore considered to have the potential to activate the Nrf2 transcription factor (sensitizing potential).