3-(1H-benzimidazol-2-yl)-7-(diethylamino)-2-benzopyrone

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Coumarin 7 failed to induce gene mutation in the Salmonella typhimurium strains TA1538, TA98 and TA100 with and without metabolic activation. Thus, the given test material, Coumarin 7, is negative for gene mutation in vitro.

Link to relevant study records

Reference

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Data is from peer reviewed journal

Qualifier:

according to guideline

Guideline:

other: as per mentioned below

Principles of method if other than guideline:

Method as described by Ames et al 1975

GLP compliance:

not specified

Type of assay:

bacterial gene mutation assay

Target gene:

Histidine

Species / strain / cell type:

S. typhimurium, other: Salmonella typhimurium strains TA1538, TA98 and TA100

Details on mammalian cell type (if applicable):

Not applicable

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Metabolic activation system:

no data

Test concentrations with justification for top dose:

0.1 mg/plate and 1 mg/plate

Vehicle / solvent:

DMSO

Untreated negative controls:

not specified

Negative solvent / vehicle controls:

not specified

True negative controls:

not specified

Positive controls:

not specified

Positive control substance:

not specified

Remarks:

no data

Details on test system and experimental conditions:

Details on test system and conditions
METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Preincubation period:
- Exposure duration: 2 days
- Expression time (cells in growth medium): 2 days
- Selection time (if incubation with a selection agent): No data available
- Fixation time (start of exposure up to fixation or harvest of cells): No data available

SELECTION AGENT (mutation assays): No data available
SPINDLE INHIBITOR (cytogenetic assays): No data available
STAIN (for cytogenetic assays): No data available

NUMBER OF REPLICATIONS: duplicate

NUMBER OF CELLS EVALUATED: No data available

DETERMINATION OF CYTOTOXICITY
- Method: mitotic index; cloning efficiency; relative total growth; other: No data available

OTHER EXAMINATIONS: No data available
- Determination of polyploidy: No data available
- Determination of endoreplication: No data available
- Other: No data available

OTHER: No data available

Evaluation criteria:

A sample was judged mutagenic if it produced greater than twice the spontaneous background colonies at more than one dose or at the highest dose tested.

Statistics:

No data available

Species / strain:

S. typhimurium, other: Salmonella typhimurium strains TA1538, TA98 and TA100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

not specified

Untreated negative controls validity:

not specified

Positive controls validity:

not specified

Additional information on results:

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: Less soluble in DMSO

RANGE-FINDING/SCREENING STUDIES: Spot test was performed with and without activation using the Salmonella typhimurium strains TA1538, TA98 and TA100. The spot test results were inconclusive. The dyes were than screened at 0.1 mg/plate and 1 mg/plate.

COMPARISON WITH HISTORICAL CONTROL DATA: No data available

ADDITIONAL INFORMATION ON CYTOTOXICITY: No data available

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Conclusions:

Interpretation of results (migrated information):
negative with and without

The given test material does not induce gene toxicity in the Salmonella typhimurium strains TA1538, TA98 and TA100. Hence it is negative for gene mutation.

Executive summary:

Liquid-dye lasers are being used in a variety of applications because of their versatility. To date there is little information available on many such dyes since there has been minimal testing of their toxicity and mutagenicity. Because laser technology is an important part of a growing number of research and development procedures and the dyes are potentially genotoxic, special precautions and handling procedures may be required.

One of the families of dyes that are involved in the study is coumarins. Amongst the 12 coumarins studied, the test material Coumarin 7 is also studied for mutagenicity. Bacteria were grown overnight in Oxoid nutrient broth, then refrigerated at 4-5^OC for a few hours before use. 0.1 ml of bacterial culture was added to 2 ml of 45°C molten top agar containing 0.01 mg histidine HCI and 0.012 mg biotin/ml, followed by the test sample in ≤0.2 ml DMSO. Finally, 0.5 ml of sodium phosphate buffer, pH 7.4 (no activation), or 0.5 ml of Aroclor-induced rat S9 mixture was added, and the mixture was poured on minimal glucose agar plates. Histidine revertant colonies were counted on a Biotran II automated colony counter after a 2-day incubation at 37°C. A sample was judged mutagenic if it produced greater than twice the spontaneous background colonies at more than one dose or at the highest dose tested. To estimate mutagenic potency (revertant/µg) from linear dose-response curves, we used the method of Moore and Felton. All compounds were tested to a level at which they were toxic or to the limits of solubility. Duplicate plates were run on all tests except high-performance liquid chromatography (HPLC) fractions. All results were verified in repeat experiments. In the above mentioned study, coumarin 7, the test material failed to induce gene mutation in theSalmonella typhimuriumstrains TA1538, TA98 and TA100 with and without metabolic activation.

Thus the given test material, Coumarin 7, is negative for gene mutation in vitro.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Additional information

Additional information from genetic toxicity in vitro:

Gene mutation in vitro:

Data from peer reviewed publications for the target chemical and data from read across (RA CAS no 91 -44 -1) have been used to determine the mutagenic nature of the test chemical Coumarin 7 (CAS no 27425 -55 -4). The summary is mentioned below:

Liquid-dye lasers are being used in a variety of applications because of their versatility. To date there is little information available on many such dyes since there has been minimal testing of their toxicity and mutagenicity. Because laser technology is an important part of a growing number of research and development procedures and the dyes are potentially genotoxic, special precautions and handling procedures may be required.

One of the families of dyes that are involved in the study is coumarins. Amongst the 12 coumarins studied, the test material Coumarin 7 is also studied for mutagenicity (Weubbles et al, 1985). Bacteria were grown overnight in Oxoid nutrient broth, then refrigerated at 4-5^OC for a few hours before use. 0.1 ml of bacterial culture was added to 2 ml of 45°C molten top agar containing 0.01 mg histidine HCI and 0.012 mg biotin/ml, followed by the test sample in ≤0.2 ml DMSO. Finally, 0.5 ml of sodium phosphate buffer, pH 7.4 (no activation), or 0.5 ml of Aroclor-induced rat S9 mixture was added, and the mixture was poured on minimal glucose agar plates. Histidine revertant colonies were counted on a Biotran II automated colony counter after a 2-day incubation at 37°C. A sample was judged mutagenic if it produced greater than twice the spontaneous background colonies at more than one dose or at the highest dose tested. To estimate mutagenic potency (revertant/µg) from linear dose-response curves, we used the method of Moore and Felton. All compounds were tested to a level at which they were toxic or to the limits of solubility. Duplicate plates were run on all tests except high-performance liquid chromatography (HPLC) fractions. All results were verified in repeat experiments. In the above mentioned study, coumarin 7, the test material failed to induce gene mutation in the Salmonella typhimurium strains TA1538, TA98 and TA100 with and without metabolic activation. Thus the given test material, Coumarin 7, is negative for gene mutation in vitro.

The Salmonella/mammalian microsome test was performed (Haworth et al, 1983) to determine the mutagenic nature of the test compound 7-Diethylamino-4-methyl coumarin in vitro. Preincubation assay was performed using Salmonella typhimurium TA100, TA1535, TA1537, TA98 with and without S9 metabolic activation system.To select the dose range for the mutagenesis assay, the test chemicals were checked for toxicity to TA100 up to a concentration of 10 mg/plate or the limit of solubility, both in the presence and absence of S-9 mix. The doses thus selected were 0, 100, 333, 1000, 3333, 5450 µg/plate. Appropriate positive controls were also incorporated. The test compound 7-Diethylamino-4-methyl coumarin is not mutagenic to Salmonella typhimurium TA100, TA1535, TA1537, TA98 in the preincubation assay performed with and without S9 metabolic activation system.preincubation assay performed with and without S9 metabolic activation system.

Gene mutation study was performed by Wuebbles, 1985 to evaluate the mutagenic nature of the test compound Coumarin 30 (RA CAS no 41044 -12 -6) using Salmonella typhimurium strain TA1538, TA98 and TA100 with and without S9 metabolic activation system. Bacteria were grown overnight in Oxoid nutrient broth, then refrigerated at 4-5^OC for a few hours before use. 0.1 ml of bacterial culture was added to 2 ml of 45°C molten top agar containing 0.01 mg histidine HCI and 0.012 mg biotin/ml, followed by the test sample in ≤0.2 ml DMSO. Finally, 0.5 ml of sodium phosphate buffer, pH 7.4 (no activation), or 0.5 ml of Aroclor-induced rat S9 mixture was added, and the mixture was poured on minimal glucose agar plates. Histidine revertant colonies were counted on a Biotran II automated colony counter after a 2-day incubation at 37°C. A sample was judged mutagenic if it produced greater than twice the spontaneous background colonies at more than one dose or at the highest dose tested. In the above mentioned study, coumarin 30, the test material failed to induce gene mutation in theSalmonella typhimuriumstrains TA1538, TA98 and TA100 with and without metabolic activation.

Hence the given test material, Coumarin 30, is not likely to be a gene mutant in vitro.

Based on the data presented, the test material Coumarin 7 (CAS no 27425 -55 -4) is not likely to be mutagenic in vitro.

Justification for selection of genetic toxicity endpoint
Data is from K2 peer reviewed publication

Justification for classification or non-classification

Based on the key study and its supporting data presented, the test material Coumarin 7 (CAS no 27425 -55 -4) is not likely to be mutagenic in vitro.