2',3,4',5,7-pentahydroxyflavone

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)

GLP compliance:

yes (incl. QA statement)

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

2',3,4',5,7-pentahydroxyflavone

EC Number:

207-542-9

EC Name:

2',3,4',5,7-pentahydroxyflavone

Cas Number:

480-16-0

Molecular formula:

C15H10O7

IUPAC Name:

2',3,4',5,7-pentahydroxyflavone

Constituent 2

Reference substance name:

Morin

IUPAC Name:

Morin

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Study design: in vivo (LLNA)

Vehicle:

dimethylformamide

Concentration:

max. 5 % (w/v)

No. of animals per dose:

4

Results and discussion

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Remarks on result:

other: concentration 5 %: 1.2 concentration 2.5 %: 1.4 concentration 1 %: 0.8 concentration 0.5 %: 0.7

Results 2

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: concentration 5 %: 1845.9 DPM/Mouse concentration 2.5 %: 2065.6 DPM/Mouse concentration 1 %: 1184.9 DPM/Mouse concentration 0.5 %: 1097.6 DPM/Mouse

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Remarks:

Migrated information

Conclusions:

Morin is not skin sensitising

Executive summary:

The aim of this study was to evaluate the skin sensitization potential of Morin following dermal exposure in the Local Lymph Node Assay. The maximum attainable concentration (based on solubility) was 5 % (w/v) in N,N-Dimethylformamide (DMF). Based on results of the preliminary irritation/toxicity test Morin was tested in the LLNA at concentrations of 5 %, 2.5 %, 1 % and 0.5 % (w/v) as formulations in the selected vehicle of DMF. Appropriate positive control (α-Hexylcinnamaldehyde, HCA), furthermore two negative control groups dosed with the vehicles of the test and positive control groups (DMF or AOO), respectively, were employed. The positive control item (25 % (w/v) HCA in Acetone: Olive oil 4:1 (v/v) mixture, AOO) induced significant stimulation over the relevant control (SI = 21.8) thus confirming the validity of the assay. No mortality was observed during the main test. No significant, treatment related effect on body weights or any other sign of systemic toxicity were observed in any treatment group. No signs of irritation or any other local effect were observed at the treatment site (ears) in any treatment group. No significantly increased lymphoproliferation (indicated by an SI ≥ 3) compared to the relevant control (DMF) was noted for Morin at the tested concentrations. The observed stimulation index values were 1.2, 1.4, 0.8 and 0.7 at test item concentrations of 5 %, 2.5 %, 1 % and 0.5 % (w/v), respectively. No significant dose-response relationship was observed (p = 0.29, r value = 0.71; linear regression using the SI values). According to evaluation criteria of the relevant guidelines, since no SI ≥ 3 was observed up to the maximum feasible concentration of 5 % (w/v, based on solubility in an appropriate vehicle) and the lack of a significant dose-related response are considered evidence that Morin is not a skin sensitizer. In conclusion, under the conditions of the present assay, Morin tested at the maximum feasible concentration of 5 % (based on solubility) and at concentrations of 2.5 %, 1 % and 0.5 % (w/v) as formulations in a suitable vehicle (DMF) was shown to have no skin sensitization potential in the Local Lymph Node Assay.