Registration Dossier

Toxicological information

Genetic toxicity: in vitro

Currently viewing:

Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1979
Report Date:
1979

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
tester strains which were able to detect crosslinking/oxidising agents were not used
GLP compliance:
no
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid

Method

Target gene:
his-
Species / strain
Species / strain / cell type:
other: S. typhimurium TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Metabolic activation system:
S-9 mix from Aroclor 1254 induced rat livers
Test concentrations with justification for top dose:
4, 20, 100, 500, 1000, 1500, 2000 and 2500 µg/plate
Vehicle / solvent:
Acetone
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: without S-9 mix: N-Methyl-N'-nitro-N-nitroso-guanidine for all strains; with S-9 mix: cyclophosphamide for TA 100; 2-aminoanthracene for TA 100, TA 98, TA 1537
Details on test system and experimental conditions:
METHOD OF APPLICATION: plate incorporation, two independent trials

NUMBER OF REPLICATIONS: 3
Evaluation criteria:
substances were considered as positive in the Ames test if following criteria are fulfilled:
- doubling the spontaneous mutation rate
- dose-effect-relationship observed
- reproducibility of the results

Results and discussion

Test results
Key result
Species / strain:
other: S. typhimurium TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
2000 µg/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid

Any other information on results incl. tables

Experiment 1

Dose (µg/plate)

Number of revertant colonies of 4 replicate plates with different strains of Salmonella typhimurium

TA98

TA100

TA1537

Results with S9

Aceton

47;30;30;26

141;136;136;125

10;7;11;5

4

34;24;26;42

143;146;147;141

6;11;8;7

20

33;26;24;31

119;135;118;129

10;6;10;13

100

n.d.;24;25;48

124;142;135;142

14;6;7;11

500

20;18;30;37

129;163;127;125

4;6;8;7

1000

1500

2000

2500

31;24;38;27

78;80;115;136

6;8;8;7

2-AA (10.0)

700;515;1035;520

1420;1460;1530;1550

78;78;98;68

Cyclopho. (500)

220;236;194;248

MNNG (5)

Results without S9

Aceton

21;28;35;30

109;96;115;108

10;8;6;2

4

26;n.d.;35;32

98;130;135;116

4;7;5;3

20

32;37;27;32

149;121;113;115

5;2;6;5

100

15;44;23;30

120;145;101;102

6;5;3;5

500

20;24;23;28

134;154;114;145

3;2;5;4

1000

1500

2000

2500

n.d.;17;15;18 (B)

108;98;102;113 (B)

4;n.d.;5;n.d.

MNNG (5)

2013;2100;1950;2250

13;18;17;19

B= reduced background growth

n.d.= not determined

 

Experiment 2

Dose (µg/plate)

Number of revertant colonies of 4 replicate plates with different strains of Salmonella typhimurium

TA98

TA100

TA1537

Results with S9

Aceton

32;27;22;27

114;103;79;95

5;6;8;4

4

20

100

24;24;26;21

112;91;83;103

9;10;6;5

500

25;21;29;26

102;90;93;118

6;7;4;8

1000

24;33;25;20

103;87;104;91

7;7;5;4

1500

28;13;22;18

81;90;91;86

7;10;6;10

2000

21;15;24;24

56;32;57;69 (B)

7;4;6;6

2500

7;18;19;17 (B)

64;44;66;76 (B)

4;6;5;3 (B)

2-AA (10.0)

559;537;498;315

856;1000;1044;929

75;70;61;60

Cyclopho. (500)

225;218;215;198

MNNG (5)

Results without S9

Aceton

20;54;35;30

149;144;165;155

3;6;6;3

4

20

100

61;n.d.;37;23

143;148;173;124

8;2;5;3

500

38;42;43;n.d.

136;156;120;144

4;5;3;2

1000

41;45;29;35

139;158;130;169

7;6;5;4

1500

42;51;34;n.d.

143;135;130;142

6;4;5;3

2000

35;52;n.d.21

130;n.d.;134;105

10;8;n.d.;5

2500

33;27;33;n.d.

56;96;124;85

n.d.;6;n.d.;9

MNNG (5)

1760;1600;1500;1760

2400;2560;220;2420

16;14;17;24

B= reduced background growth

n.d.= not determined

 

 

The test item was neither mutagenic in the Ames-test with metabolic activation by S-9 mix, nor without. The amount of revertants was in the range of the negative controls (differences not significant).

The test item demonstrated to be toxic for the Salmonella strains employed upon concentrations > 2000 µg/plate.

 Positive controls showed a distinct increase in revertants in all experimental approaches.

Applicant's summary and conclusion

Conclusions:
The test substance under the experimental conditions described was not mutagenic.
Executive summary:

A bacterial reverse mutation assay (plate incorporation, two independent trials) similar to OECD Guideline 471 was conducted. S. typhimurium TA 1537, TA 98 and TA 100 was exposed to test item concentrations of 4 - 2500 µg/plate. As vehicle acetone was used. In addition , negative controls, solvent controls and positive controls were performed (without S-9 mix: N-Methyl-N'-nitro-N-nitroso-guanidine for all strains; with S-9 mix: cyclophosphamide for TA 100; 2-aminoanthracene for TA 100, TA 98, TA 1537). Tester strains which were able to detect crosslinking/oxidising agents were not used. The test item was considered to be positive in the Ames test if the spontaneous mutation rate doubled, dose-effect-relationship was observed and if the results are reproducible. In result, the test item was neither mutagenic in the Ames-test with metabolic activation by S-9 mix, nor without. The amount of revertants was in the range of the negative controls (differences not significant). The test item demonstrated to be toxic for the Salmonella strains employed upon concentrations > 2000 µg/plate. Positive controls showed a distinct increase in revertants in all experimental approaches. In conclusion, these results indicate that the test substance under the experimental conditions described, was not mutagenic to Salmonella typhimurium strains TA 1537, TA 98 and TA 100 in the presence and absence of a metabolizing system.