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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
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Comparable to guideline study with acceptable restrictions. Restriction: only 2 strains of S. typhimurium used.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1991
Report Date:
1991

Materials and methods

Principles of method if other than guideline:
Reverse mutation according to Ames, B. N. et al., Proc. Nat. Acad. Sci. USA, 70, 2281-2285 (1973). Modification described by Rannug et al., Chem. Biol. Interaction, 12, 151-263 (1976) and Lutz et al., Mut. Res., 93, 305-315 (1982)
GLP compliance:
no
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): 3-Methyl-2-butenal, CAS: 107-86-8
- Analytical purity: 98%
- Lot/batch No.: B 2240/12.04.88
- Storage condition of test material: room temperature

Method

Target gene:
Salmonella/Mammalian-Microsomes
Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 98
Species / strain / cell type:
S. typhimurium TA 100
Metabolic activation:
with and without
Metabolic activation system:
liver S9 Aroclor 1254-induced
Test concentrations with justification for top dose:
20, 100, 500, 2000, 2500, 3000, 4000, 5000, 6000 ug/plate
Vehicle / solvent:
water
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: with S-9: 2-aminoanthracene (2-AA) (DMSO) for TA 100 and TA 98; without S-9: N-methyl-N*-nitro-N-nitrosoguanidine (MNNG) (DMSO) for the strain TA 100 4-nitro-o-phenylendiamine (NPD) (DMSO) for the strain TA 98
Evaluation criteria:
In general, a substance to be characterized as positive in the Ames test has to fulfill the following requirements:
- doubling of the spontaneous mutation rate (control)
- dose-response relationship
- reproducibility of the results
Statistics:
none

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium TA 98
Metabolic activation:
with and without
Genotoxicity:
positive
Cytotoxicity / choice of top concentrations:
other: 1000-3000 µg/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with and without
Genotoxicity:
positive
Cytotoxicity / choice of top concentrations:
other: 1000-3000 µg/plate
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
Positive controls validity:
valid
Additional information on results:
Results without S9-mix: TA 100 was weakly positive (2.1-2.5-fold) in the 1st experiment at 2500-5000 ug/plate and more positive in subsequent experiments from 100-500 ug/plate (factor 1.7-4.6) with a maximum at 1000-3000 ug/plate (factor 6.0-8.1). TA 98 showed a slight increase (factor 2.1) at 2500 µg/plate which was not concentration dependent.
Results with S9-mix: With TA 100 increased revertant numbers were seen at very high concentrations in the first experiment (1.6-fold at 5000 ug/plate) and in the second experiment (2.5-fold at 2000 ug/plate). In the third experiment mutagenicity was seen at lower concentrations (2.4-2.7-fold at 100-500 ug/plate). TA 98 showed no increased number of revertants. Cytotoxicity was observed only in the 2nd and 3rd experiment using TA 100 from 1000-3000 ug/plate.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

TA 100

Dose (mg/plate)

S9-mix

mean

SD

S9-mix

mean

SD

negative ctrl

- S9

106

8

+S9

124

8

20

98

9

108

14

100

100

7

96

12

500

123

14

90

16

2500

219

28

122

28

5000

265

44

199

60

positive ctrl (2-AA)

n.d.

n.d.

851

497

positive ctrl (MNNG)

670

3

n.d.

n.d.

positive ctrl (CA)

265

17

n.d.

n.d.

positive ctrl (MVK)

261

19

n.d.

n.d.


TA 98

Dose (mg/plate)

S9-mix

mean

SD

S9-mix

mean

SD

negative ctrl

- S9

40

3

+S9

37

6

20

37

7

32

2

100

33

3

39

5

500

34

3

34

6

2500

84

8

31

2

5000

49

9

29

2

positive ctrl (NPD)

581

104

n.d.

n.d.

positive ctrl (2-AA)

n.d.

n.d.

2113

110

Test 2:

TA 100

Dose (mg/plate)

S9-mix

mean

SD

S9-mix

mean

SD

negative ctrl

- S9

126

7

+S9

139

12

2000

1013

26

349

59

3000

865

22

-

-

4000

300

8

-

-

5000

-

-

0

0

6000

0

0

0

0

positive ctrl (2-AA)

n.d.

n.d.

2313

244

positive ctrl (MNNG)

2927

64

n.d.

n.d.

positive ctrl (CA)

1317

51

n.d.

n.d.

positive ctrl (MVK)

544

31

n.d.

n.d.


TA 98

Dose (mg/plate)

S9-mix

mean

SD

S9-mix

mean

SD

negative ctrl

- S9

125

11

+S9

115

17

100

208

14

279

60

500

579

37

309

38

1000

743

91

76

45

2000

331

20

37

9

3000

234

78

28

5

positive ctrl (2-AA)

n.d.

n.d.

1643

199

positive ctrl (MNNG)

1527

119

n.d.

n.d.

positive ctrl (CA)

779

31

n.d.

n.d.

positive ctrl (MVK)

489

34

n.d.

n.d.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
positive

Positive results of the study are ambiguous since the
effects were not coherent between the three experiments and the dose-relationship was not clear.