(2E)-2-methyl-3-phenylacrylaldehyde

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1998

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

Comparable to OECD Guideline 471. Deficiencies were: Salmonella strains TA1535 and TA98 not tested (guideline recommends testing both); TA1537, TA97 and TA97a not tested (guideline recommends testing at least one of these)

Data source

Reference

Reference Type:

publication

Title:

The effectiveness of Salmonella strains TA100, TA102 and TA104 for detecting mutagenicity of some aldehydes and peroxides

Author:

Diilon, D., Combes, R., and Zeiger, E.

Year:

1998

Bibliographic source:

Mutagenesis vol.13 no.1 pp.19-26, 1998

Materials and methods

Test guideline

Qualifier:

equivalent or similar to

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

guideline also recommends testing TA1535, TA98 and at least one of TA1537, TA97 and TA97a; 2-aminoanthracene not recommended as sole indicator of S-9 activity

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Reference

Name:

Unnamed

Type:

Constituent

Test material form:

liquid

Specific details on test material used for the study:

Test material is described using the generic CAS 101-39-3, however the name is given as α-Methyl-trans-cinnamaldehyde (sourced from Aldrich).

Method

Species / strain

Species / strain / cell type:

S. typhimurium, other: TA100, TA102, TA104

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Metabolic activation system:

Aroclor 1254-induced rat and mouse liver fractions (S9)

Test concentrations with justification for top dose:

No metabolic activation: 10 to 1000 μg/plate (TA 100 and TA102); 100 to 10,000 μg/plate (TA104)
With metabolic activation (mouse S9): 10 to 10,000 μg/plate (TA100); 100 to 10,000 μg/plate (TA102); 10 to 1000 μg/plate (TA104)
With metabolic activation (rat S9): 10 to 1000 μg/plate (TA100 and TA104); 10 to 10,000 μg/plate (TA102)

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: no data
- Justification for choice of solvent/vehicle: no data

Controls

Controls 1

Untreated negative controls:

yes

Remarks:

dose of 0 μg/plate tested [no further details given]

Positive controls:

yes

Remarks:

with S9 (all strains)

Positive control substance:

other: 2-aminoanthracene

Controls 2

Untreated negative controls:

yes

Remarks:

dose of 0 μg/plate tested [no further details given]

Positive controls:

yes

Remarks:

without S9 (TA100)

Positive control substance:

other: methylmethanesulphonate

Controls 3

Untreated negative controls:

yes

Remarks:

dose of 0 μg/plate tested [no further details given]

Positive controls:

yes

Remarks:

without S9 (TA102)

Positive control substance:

mitomycin C

Controls 4

Untreated negative controls:

yes

Remarks:

dose of 0 μg/plate tested [no further details given]

Positive controls:

yes

Remarks:

without S9 (TA104)

Positive control substance:

other: formaldehyde or crotonaldehyde

Details on test system and experimental conditions:

METHOD OF APPLICATION: preincubation

DURATION
- Preincubation period: performed to the protocol of Maron and Ames (1983) [20 min at 37 °C or 30 min at 30 °C]
- Exposure duration: performed to the protocol of Maron and Ames (1983) [48 h]

NUMBER OF REPLICATIONS: 3 plates/dose

DETERMINATION OF CYTOTOXICITY
- Method: other: thinning of the background lawn and/or a reduction in the number of colonies on the plates

Evaluation criteria:

Responses were judged mutagenic (+) when there was a reproducible, dose-related response and weakly mutagenic (+w) when reproducible low-level increases were obtained or when both positive and equivocal responses were seen in repeat trials. Responses were judged equivocal (?) when the increases in revertants were not reproducible or were seen only at a single dose.

Statistics:

The significance of mean revertant counts at individual dose levels was assessed using Dunnett’s t-test and dose-response effects were analyzed by two methods, Wahrendorf ranking and linear regression (Mahon et al., 1989). The latter was used to obtain slope of the responses and both methods were only applied in the absence of a decline in revertant count at high dose levels. These analyses were used for guidance, but did not dictate the summary responses.

Results and discussion

Test results

Key result

Species / strain:

S. typhimurium, other: TA 100, TA102, TA104

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: highest dose (1000 or 10,000 μg/plate, depending on strain) apparently "limited by toxicity"

Vehicle controls validity:

not specified

Untreated negative controls validity:

not specified

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Effects of pH: no data available
- Effects of osmolality: no data available
- Evaporation from medium: no data available
- Water solubility: no data available
- Precipitation: no data available
- Other confounding effects: no data available

RANGE-FINDING/SCREENING STUDIES: no data available

COMPARISON WITH HISTORICAL CONTROL DATA: no data available

ADDITIONAL INFORMATION ON CYTOTOXICITY: no data available

OTHER: Test compound produced "inconsistent equivocal responses" in TA100 with mouse and rat S9, but was not considered mutagenic

Any other information on results incl. tables

Table 1. Mutagenicity of α-Methyl-trans-cinnamaldehyde
α-Methyl-trans-cinnamaldehyde		TA100	TA102	TA104
	-S9	-	-	-
	+S9	-	-	-

- non-mutagenic

Applicant's summary and conclusion

Conclusions:

Interpretation of results: negative

In a limited Ames test, similar to that recommended by OECD Guideline 471, α-methyl-trans-cinnamaldehyde showed no consistent evidence of mutagenic activity in three strains of Salmonella typhimurium, with or without S9.

Executive summary:

A publication briefly describes a bacterial reverse mutagenicity (Ames) assay, in a preincubation test conducted using a protocol similar to OECD Guideline 471.

Salmonella typhimurium strains TA100, TA102 and TA104 were tested with α-methyl-trans-cinnamaldehyde at up to 1,000 or 10,000 μg/plate (depending on strain, and apparently "limited by toxicity") in the presence or absence of a rat or mouse liver metabolic activation fraction (S9). Known mutagens were also tested as positive controls. Three plates were prepared for each concentration and incubated, after which the number of revertant colonies per plate was counted.

No reproducible, dose-related mutagenic response was observed. Under the conditions of this assay (which did not test the guideline recommended set of five S. typhimurium strains), α-methyl-trans-cinnamaldehyde showed no convincing evidence of mutagenic activity in S. typhimurium, with or without S9.