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Toxicological information

Genetic toxicity: in vitro

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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:
1993
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference
Reference Type:
publication
Title:
Photochemical decompositon of organic compounds in water after UV-irradiation: investigation of positive mutagenic effects
Author:
I. de Veer, H.-J. Moriske, H. Ridden
Year:
1994
Bibliographic source:
Toxicology Letters, 72 (1994), 113-119

Materials and methods

Test guidelineopen allclose all
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
not specified
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 479 (Genetic Toxicology: In Vitro Sister Chromatid Exchange Assay in Mammalian Cells)
Deviations:
not specified
GLP compliance:
not specified
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Target gene:
no data
Species / strainopen allclose all
Species / strain:
S. typhimurium TA 98
Additional strain characteristics:
not specified
Metabolic activation:
with and without
Species / strain:
S. typhimurium TA 100
Additional strain characteristics:
not specified
Metabolic activation:
with and without
Species / strain:
Chinese hamster lung fibroblasts (V79)
Additional strain characteristics:
not specified
Metabolic activation:
with and without
Test concentrations with justification for top dose:
2.00 mg/ml
Vehicle:
- Vehicle(s)/solvent(s) used: purified water (testing with UV-radiation), DMSO (test assays without UV-radiation)
Controls
Positive controls:
yes
Positive control substance:
sodium azide
benzo(a)pyrene
other: 2-nitrofluorene, 2-aminoanthracene, epichlorhydrine
Details on test system and conditions:
The test procedure of Maron and Ames was used and the mutagenicity factor for each sample was calculated by number of revertants of test substance/plate and number of spontaneous revertants/plate (rev./pl.).
For SCE-assay V79 Chinese hamster cells were grown in minimal essential medium (MEM) with Earle’s salts supplemented with 10% fetal calf serum and antibiotics. Cells were treated with the test substance for 2.5 h. Chromosome preparation and staining were performed according to standard protocols. Epichlorhydrine (1.0; 0.5; 0.25 mM) and benzo(a)pyrene (0.08; 0.04; 0.02 mM) were used as positive controls with and without metabolic activation. For each experimental data point 25 second division metaphases were scored and the mean values of SCEs per 22 chromosomes were evaluated.
In the case of testing with UV-irradiation the compounds were dissolved in 1000 ml purified water. The samples were irradiated either by low- or high-pressure vapor UV lamps with a fluence of 2500 J/m2. UV-irradiation doses up to 10 times the doses for physical disinfection were used. Dimethylsulfoxide (DMSO) was added as organic solvent to the irradiated samples. The water phase was extracted using evaporation equipment and the remaining DMSO-phase contained the organic components. Recovery rates above 90% for each compound were determined by HPLC. In parallel experiments the organic compounds were directly dissolved in DMSO for test assays without UV-irradiation. All samples were tested for mutagenicity both with Ames- and SCE-tests.

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium TA 98
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity:
no
Positive controls valid:
yes
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity:
no
Positive controls valid:
yes
Species / strain:
Chinese hamster lung fibroblasts (V79)
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity:
no
Positive controls valid:
yes

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

L-phenylalanine was examined in Ames-test (bacterial strains TA 98 and TA 100) and sister chromatid exchange (SCE)-test (V79 cells) before and after UV-irradiation. Based on results in Ames- and SCE-test a mutagenic activity was not obtained for all L-phenylalanine samples, neither before nor after UV-irradiation.