Registration Dossier

Administrative data

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

2-Methyl-3-phenyl-2-propenal showed no convincing evidence of mutagenic potential in good-quality Ames bacterial tests involving seven strains of Salmonella typhimurium and one Escherichia coli strain, with and without added activation (S9). A SOS chromotest with E. coli was also negative.


Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (negative)

Genetic toxicity in vivo

Description of key information

No in vivo cytogenetic or gene mutation studies in mammalian cells are available for 2-methyl-3-phenyl-2-propenal. However, an in vivo bone marrow micronucleus test in mice and a gene mutation test in Drosophila melanogaster found no evidence of genotoxic activity. Overall, the available data indicate that 2-methyl-3-phenyl-2-propenal does not possess genotoxic potential.

Link to relevant study records
Reference
Endpoint:
in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus
Remarks:
Type of genotoxicity: chromosome aberration
Type of information:
experimental study
Adequacy of study:
key study
Study period:
no data available
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions
Remarks:
Comparable to OECD Guideline 474. Deficiencies were: only four animals tested per dose; bone marrow taken only once, six hours after final treatment; only 1000 erythrocytes scored per animal
Reference:
Composition 0
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
Deviations:
yes
Remarks:
4 animals/dose (guideline recommends ≥ 5/sex/dose); bone marrow taken once, 6 h after final treatment (guideline recommends taking twice, 18-24 and 36-48 h after final treatment); 1000 erythrocytes scored (guideline recommends ≥ 2000)
GLP compliance:
not specified
Type of assay:
micronucleus assay
Test material information:
Composition 1
Specific details on test material used for the study:
Source: ICN-K &K (Plainview, NY, USA)
Species:
mouse
Strain:
NMRI
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: lvanovas GmbH (Kisslegg)
- Age at study initiation: 10 to 14 weeks
- Weight at study initiation: no data available
- Assigned to test groups randomly: no data available
- Fasting period before study: no data available
- Housing: no data available
- Diet (e.g. ad libitum): standard chow (Altromin) ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: no data available

ENVIRONMENTAL CONDITIONS
- Temperature (°C): no data available
- Humidity (%): no data available
- Air changes (per hr): no data available
- Photoperiod (hrs dark / hrs light): no data available

IN-LIFE DATES: no data available
Route of administration:
intraperitoneal
Vehicle:
- Vehicle(s)/solvent(s) used: olive oil
- Justification for choice of solvent/vehicle: no data available
- Concentration of test material in vehicle: no data available
- Purity: no data available
Details on exposure:
intraperitoneal injections
Duration of treatment / exposure:
single injections at 0 and 24 h
Frequency of treatment:
once daily, for 2 days
Post exposure period:
6 hours
Remarks:
Doses / Concentrations:
438, 292 or 146 mg/kg bw/day
Basis:
no data
No. of animals per sex per dose:
probably 2 [4 animals/dose tested]
Control animals:
other: yes: concurrent negative controls (possibly given vehicle or no treatment)
Positive control(s):
no data
- Justification for choice of positive control(s): no data available
- Route of administration: no data available
- Doses / concentrations: no data available
Tissues and cell types examined:
bone marrow micronucleated polychromatic erythrocytes
Details of tissue and slide preparation:
CRITERIA FOR DOSE SELECTION: no data available

TREATMENT AND SAMPLING TIMES (in addition to information in specific fields): treatment at 0 and 24 hours, sampling at 30 hours

DETAILS OF SLIDE PREPARATION: stained with May-Gruenwald and Giemsa stains. 1000 polychromatic erythrocytes analysed for each animal on coded slides.

METHOD OF ANALYSIS: no data available
Evaluation criteria:
no data available
Statistics:
no data available
Key result
Sex:
male/female
Genotoxicity:
negative
Toxicity:
not specified
Vehicle controls valid:
other: possibly negative control
Negative controls valid:
yes
Positive controls valid:
not specified
Additional information on results:
RESULTS OF RANGE-FINDING STUDY
- Dose range: no data available
- Solubility: no data available
- Clinical signs of toxicity in test animals: no data available
- Evidence of cytotoxicity in tissue analyzed: no data available
- Rationale for exposure: no data available
- Harvest times: no data available
- High dose with and without activation: no data available

RESULTS OF DEFINITIVE STUDY
- Induction of micronuclei (for Micronucleus assay): no data available
- Ratio of PCE/NCE (for Micronucleus assay): 1.7, 2.0 and 2.2 per thousand (for animals given 438, 292 and 146 mg/kg bw/day respectively). 2.0 per thousand for negative control.
- Appropriateness of dose levels and route: no data available
- Statistical evaluation: no data available
Conclusions:
Interpretation of results: negative
In an in vivo bone marrow micronucleus test, similar to that recommended by OECD Guideline 474, no consistent evidence of mutagenic activity was observed in mice following intraperitoneal injections of α-methylcinnamaldehyde at up to 438 mg/kg bw/day for 2 days.
Executive summary:

A publication briefly describes an in vivo micronucleus test carried out on groups of mice, conducted using a protocol similar to OECD Guideline 474.

Groups of four mice were given two intraperitoneal injections (at 0 and 24 hours) of α-methylcinnamaldehyde at 146, 292 or 438 mg/kg bw/day. Six hours after the final injection, mice were killed, and bone-marrow smears were prepared. Following fixation and staining, 1000 polychromatic erythrocytes were analysed from each animal, and the number of micronucleated polychromatic erythrocytes was recorded.

Treatment with α-methylcinnamaldehyde did not significantly induce increased numbers of micronuclei. Under the conditions of this assay, no convincing evidence of mutagenic activity was demonstrated for α-methylcinnamaldehyde.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (negative)

Additional information

In good-quality studies, 2-methyl-3-phenyl-2-propenal exhibited no mutagenic activity, either in the presence or absence of rat, mouse or hamster liver metabolic activating fractions (S9), in six strains of Salmonella typhimurium (TA98, TA102, TA104, TA1535, TA1537 and TA1538) (Dillon et al. 1992a,b, 1998; Kato et al. 1989; Mortelmans et al. 1986; NTP, 1988; Wild et al. 1983). [Note: TA104 and TA1538 are additional to the current OECD Guideline’s recommended set of five tester strains.] For S. typhimurium strain TA100, results for mutagenicity have generally been negative (Kato et al. 1989; Mortelmans et al. 1986; Neudecker et al. 1983; Wild et al. 1983), but some weak/equivocal responses have been reported for this strain in the presence of metabolic activation (Dillon et al. 1992a,b; Dillon et al. 1998; NTP, 1988). In addition, mutagenic activity was not seen in Escherichia coli strain WP2uvrA/pKM101, with and without S9 (Kato et al. 1989) or in the SOS chromotest withE. coliPQ37 (Eder et al. 1993).

 

No in vitro cytogenetic or micronucleus studies in mammalian cells are available on 2‑methyl-3-phenyl-2-propenal. However, in accordance with column 2 of REACH Annex VIII, these studies do not usually need to be conducted if adequate data from an in vivo cytogenicity test are available. In this instance, a bone marrow micronucleus test has been conducted. No evidence of chromosome damage (as measured by increases in the incidence of micronuclei) was observed in the bone marrow of groups of four mice given intraperitoneal injections of 0, 146, 292 or 438 mg/kg bw on two occasions, one day apart (Wild et al. 1983).

 

As a negative result for genotoxicity was observed in the Ames and in vivo micronucleus test, an in vitro gene mutation study in mammalian cells is required according to REACH Annex VIII. No such study is currently available. However, no evidence of heritable gene mutations was observed in the offspring of fruit flies (Drosophila melanogaster) fed 2-methyl-3-phenyl-2-propenal for 3 days (Wild et al. 1993). [The relevance of these findings to an understanding of mutagenic potential in mammalian systems is not fully established.]

 

In its evaluation of cinnamyl alcohol and related compounds (including 2-methyl-3-phenyl-2-propenal), JECFA noted a lack of direct mutagenic or genotoxic activity of 2-methyl-3-phenyl-2-propenal and considered estimated daily intake from its use as a food additive to be of no safety concern in Europe and the US (JECFA, 2001). Similarly, 2-methyl-3-phenyl-2-propenal is generally recognised as safe (GRAS) by the US Expert Panel of the Flavor and Extract Manufacturers Association (FEMA) (Adams et al. 2004).

 

Overall, the available data indicate that 2-methyl-3-phenyl-2-propenal does not possess genotoxic potential.

 

References (not contained elsewhere in this IUCLID dossier)

Adams TB et al. (2004). The FEMA GRAS assessment of cinnamyl derivatives used as flavour ingredients. Fd Chem. Toxicol. 42, 157-185.

Dillon DM et al. (1992a). Detection of mutagenicity in Salmonella of some aldehydes and peroxides. Environ. Mol. Mutagen. 19, 15.

Dillon DM et al. (1992b). Optimal conditions for detecting bacterial mutagenicity of some aldehydes and peroxides. Mutat. Res. 271, 184.

Eder E et al. (1993). The possible role of α,β-unsaturated carbonyl compounds in mutagenesis and carcinogenesis. Tox. Lett. 67, 87-103.

JECFA (2001). Joint FAO/WHO Expert Committee on Food Additives. Safety evaluation of certain food additives and contaminants. WHO Fd. Add. Ser. 46.

Kato F et al. (1989). Mutagenicity of aldehydes and diketones. Mutat. Res. 216, 366. [Abstract only.]

Neudecker T et al. (1983). Effect of methyl and halogen substitutions in theαC position on the mutagenicity of cinnamaldehyde. Mutat. Res. 110, 1-8.

NTP (1988). National Toxicology Program. Alpha-Methyl cinnamaldehyde. Salmonella (981636).

Justification for classification or non-classification

2-Methyl-3-phenyl-2-propenal showed no convincing evidence of mutagenic potential in good-quality Ames bacterial tests involving seven strains of Salmonella typhimurium and one Escherichia coli strain, with and without added activation (S9).

A SOS chromotest with E. coli was also negative. An in vivo bone marrow micronucleus test in mice and a gene mutation test in Drosophila melanogaster found no evidence of genotoxic activity.

Overall, according to the classification and labelling of the EC commission, 2-methyl-3-phenyl-2-propenal is not classified as a mutagen.