Ephedrine

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP compliant guideline study, available as unpublished report, restriction in design (only one positive control used to test efficacy of the S9-mix), but adequate for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2000

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

, only one positive control used to test efficacy of the S9-mix

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)

Deviations:

yes

Remarks:

, only one positive control used to test efficacy of the S9-mix

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

[R-(R*,S*)]-α-(1-aminoethyl)benzyl alcohol

EC Number:

207-755-7

EC Name:

[R-(R*,S*)]-α-(1-aminoethyl)benzyl alcohol

Cas Number:

492-41-1

IUPAC Name:

2-amino-1-phenylpropan-1-ol

Details on test material:

- Name of test material (as cited in study report): (-)-Norephedrin S krist.
- Appearance, consistency: white crystals
- Storage: Room temperature (protected from light)

Method

Target gene:

- S. typhimurium: His-locus
- E. coli: Trp-locus

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Additional strain / cell type characteristics:

not applicable

Species / strain 2

Species / strain / cell type:

E. coli WP2 uvr A

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with and without

Metabolic activation system:

Aroclor 1254-induced rat liver S9 mix

Test concentrations with justification for top dose:

- Experiment 1 and 2: 20, 100, 500, 2500, 5000 µg/plate
- Experment 3: 4, 20, 100, 500, 1000 µg/plate

Vehicle / solvent:

- Vehicle/solvent used: water
- Justification for choice of solvent/vehicle: due to the good solubility of the test substance in water, water was selected

Controls

Controls 1

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Remarks:

TA: 2.5 µg/plate, E.coli: 60 µg/plate

Positive control substance:

other: 2-aminoanthracene

Remarks:

All strains with metabolic activation

Controls 2

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Remarks:

5 µg/plate

Positive control substance:

other: N-methyl-N'-nitro-N-nitrosoguanidine

Remarks:

TA 1535, TA 100; without metabolic activation

Controls 3

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Remarks:

100 µg/plate

Positive control substance:

9-aminoacridine

Remarks:

TA 1537; without metabolic activation

Controls 4

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Remarks:

5 µg/plate

Positive control substance:

4-nitroquinoline-N-oxide

Remarks:

E.coli WP2 uvrA; without metabolic activation

Controls 5

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 4-nitro-o-phenylendiamine

Remarks:

TA 98; without metabolic activation

Details on test system and experimental conditions:

EXPERIMENT 1
- METHOD OF APPLICATION: in agar (plate incorporation)
- DURATION: Exposure duration: 48 - 72 h
- NUMBER OF REPLICATIONS: 3 test plates per dose or per control
- DETERMINATION OF CYTOTOXICITY: Toxicity detected by a: decrease in the number of revertants, clearing or diminution of the background lawn (= reduced his- or trp- background growth), reduction in the titer

EXPERIMENT 2 and 3
- METHOD OF APPLICATION: preincubation
- DURATION: Preincubation period: 20 min; Exposure duration: 48 - 72 h
- NUMBER OF REPLICATIONS: 3 test plates per dose or per control
- DETERMINATION OF CYTOTOXICITY: Toxicity detected by a: decrease in the number of revertants, clearing or diminution of the background lawn (= reduced his- or trp- background growth), reduction in the titer

Evaluation criteria:

- The test chemical is considered positive in this assays if the following criteria are met: A dose-related and reproducible increase in the number of revertant colonies, i.e. about doubling of the spontaneous mutation rate in at least one tester strain either without S-9 mix or after adding a metabolizing system.
- A test substance is generally considered nonmutagenic in this test if: The number of revertants for all tester strains were within the historical negative control range under all experimental conditions in two experiments carried out independently of each other.

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: no test substance precipitation was found

ADDITIONAL INFORMATION ON CYTOTOXICITY:
- Standard plate test: A slight increase in the number of revertants and/or a slight reduction in the titer was occasionally observerd in the standard plate test depending on the strain and test conditions at doses ≥2500 µg/plate.
- Preincubation test: In the preincubation assay bacteriotoxicity (reduced background growth, decrease in the number of revertant, slight reduction in the titer) was observed depending on the strain and test conditions from about 2500 µg/plate onward.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

It is concluded that there is no evidence of induction of gene mutations by the test substance and its metabolites in the strains of S. typhimurium and E. coli used.

Executive summary:

In a GLP compliant mutagenicity test, performed according to OECD guideline 471, 4 Salmonella typhimurium strains (TA 1535, TA 1537, TA 98, and TA 100) and one E. Coli strain (WP2 uvrA) were used to test the mutagenic potential of the test substance both with and without metabolic activation. Three experiments were performed. In the first experiment: a standard plate test strains were exposed to 0, 20, 100, 500, 2500, and 5000 µg/plate. The second and third experiment were preincubation tests. In the second test strains were exposed to 0, 20, 100, 500, 2500, and 5000 µg/plate and in the third test strains were exposed to 0, 4, 20, 100, 500 and 1000 µg/plate. No precipitation of the test substance was found. A bacteriotoxic effect was observed under all test conditions at concentrations ≥2500 µg/plate. An increased in the number of his+ or trp+ revertants was not observed in the standard plate test or in the preincubation test either without S9 mix or after the addition of a metabolizing system. It was therefore concluded that the test substance is not mutagenic under these experimental conditions.