2-methoxy-5-nitroanilinium chloride

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

data is from peer reviewed journals

Data source

Reference

Reference Type:

publication

Title:

Local Lymph Node Data for the Evaluation of Skin Sensitization Alternatives: A Second Compilation

Author:

Petra S. Kern, G. Frank Gerberick, Cindy A. Ryan, Ian Kimber, Aynur Aptula, and David A. Basketter

Year:

2010

Bibliographic source:

Dermatitis, Vol 21, No 1 (January/February), 2010: pp 8–32

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Principles of method if other than guideline:

To evaluate the potential of 4-Amino-3-nitrophenol for inducing allergic contact dermatitis

GLP compliance:

not specified

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

4-amino-3-nitrophenol

EC Number:

210-236-8

EC Name:

4-amino-3-nitrophenol

Cas Number:

610-81-1

Molecular formula:

C6H6N2O3

IUPAC Name:

1-Hydroxy-3-nitro-4-aminophenol

Test material form:

solid

Details on test material:

Name of the test chemical:4-Amino-3-nitrophenol
Molecular Weight: 154.124 g/mol
Molecular Formula: C6H6N2O3
Substance Type: Organic
Physical State: Solid

Specific details on test material used for the study:

Name of the test chemical:4-Amino-3-nitrophenol
Molecular Weight: 154.124 g/mol
Molecular Formula: C6H6N2O3
Substance Type: Organic
Physical State: Solid

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Age at study initiation: 7-12 weeks

Study design: in vivo (LLNA)

Vehicle:

acetone/olive oil (4:1 v/v)

Concentration:

25 µL

No. of animals per dose:

groups of female mice (number not specified)

Details on study design:

ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: LLNA
- Criteria used to consider a positive response:
A substance was classified as a skin sensitizer if it induced a threefold or greater increase in local lymph node proliferative activity at one or more test concentrations when compared with concurrent vehicle-treated controls (SI≥3). Dose response data were used to measure the relative skin sensitization potency of all of the chemicals that were positive. When the LLNA dose-response curve included concentrations that induced at least one SI greater than 3 and one SI less than 3, EC3 values were calculated by linear interpolation. For chemicals that induced an SI greater than or equal to 3 at all concentrations tested, an EC3 value was extrapolated from the two lowest doses used. For this extrapolation method to work, a dose response should be evident. The relative sensitizing potencies of the chemical allergens were categorized via a recently proposed arbitrary classification scheme.

TREATMENT PREPARATION AND ADMINISTRATION: groups of CBA female mice (7–12 weeks of age) were exposed topically on the dorsum of both ears to 25 µL of test material or to an equal volume of the relevant vehicle alone. Treatment was performed daily for 3 consecutive days. Five days after the initiation of exposure, all mice were injected via the tail vein with 250 µL of phosphate buffered saline (PBS) containing 20 µCi of tritiated thymidine. Mice were sacrificed 5 hours later, and the draining auricular lymph nodes were excised and pooled for each experimental group or each individual animal. The incorporation of tritiated thymidine measured by beta scintillation counting was reported in disintegrations per minute (dpm). A stimulation index (SI) was calculated for each chemical-treated group as the ratio of the dpm of the treated group (or mean dpm when individual animals were assessed) to the dpm or mean dpm of the concurrent vehicle control group.

Positive control substance(s):

not specified

Results and discussion

In vivo (LLNA)

Results

Parameter:

EC3

Value:

0.2

Test group / Remarks:

test group

Remarks on result:

other: Strong sensitizer

Cellular proliferation data / Observations:

The relative potency index of 4-Amino-3-nitrophenol was calculated to be 0.2

Any other information on results incl. tables

Table: Chemical Structures, Molecular Weights, LLNA Data, Potency Categorizations, and Reaction Mechanistic Domains

CAS

Name of the test chemical

Vehicle

LLNA%

LLNA%

LLNA%

LLNA%

LLNA%

LLNA SI

LLNA SI

LLNA SI

LLNA SI

LLNA SI

LLNA EC3

Relative Potency

Reaction mechanism domain

610-81-1

4-Amino-3-nitrophenol

AOO

0.05

0.1

0.5

1.0

2.5

1.7

1.8

6.9

8.9

27.7

0.2

Strong

Pro/Pro-MA

AOO- Acetone and olive oil(4:1); LLNA – Local lymph node assay (LLNA% = weight per volume concentration), Pro/Pre – Not direct-acting electrophiles but able to be converted to electrophiles by well-established transformations (abiotic or metabolic), MA –Michaels acceptor

Applicant's summary and conclusion

Interpretation of results:

other: Strong Sensitizer

Conclusions:

The relative potency index of 4-Amino-3-nitrophenol was calculated to be 0.2.
Based on the relative potency index, 4-Amino-3-nitrophenol was considered to be a strong sensitizer.

Executive summary:

The dermal sensitization potential of 4-Amino-3-nitrophenol was evaluated in a mouse local lymphnode assay(LLNA). The study was performed as per OECD 429 Guidelines. Groups of female CBA mice (7-12 weeks of age) were exposed topically on the dorsum of both ears to 25µl of the test material or to an equal volume of relevant vehicle only. Treatment was performed daily for 3 consecutive days.Five days after the initiation of exposure, all mice were injected via the tail vein with 250 µL of phosphate buffered saline (PBS) containing 20 µCi of tritiated thymidine. Mice were sacrificed 5 hours later, and the draining auricular lymph nodes were excised and pooled for each experimental group or each individual animal. The incorporation of tritiated thymidine measured by beta scintillation counting was reported in disintegrations per minute (dpm). A stimulation index (SI) was calculated for each chemical-treated group as the ratio of the dpm of the treated group (or mean dpm when individual animals were assessed) to the dpm or mean dpm of the concurrent vehicle control group.The approach to estimation of the relative skin sensitization potential was based on the mathematical estimation of the concentration of chemical necessary to obtain a threshold positive response (SI = 3); this is termed as the EC3 value.A substance was classified as a skin sensitizer if it induced a threefold or greater increase in local lymph node proliferative activity at one or more test concentrations when compared with concurrent vehicle-treated controls (SI≥3).

 

The relative potency index of 4-Amino-3-nitrophenol was calculated to be 0.2.

Based on the relative potency index, 4-Amino-3-nitrophenol was considered to be a strong sensitizer.