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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:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The test was conducted according to the acknowledged method of Ames et al. (Proc. Nat. Acad. Sci. 70: 2281-2285 & 782-786, 1973 and Mutat. Res. 31: 347-364, 1975).

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1986

Materials and methods

Principles of method if other than guideline:
Method: other:
The test was conducted according to the acknowledged method of Ames et al. (Proc. Nat. Acad. Sci. 70: 2281-2285 & 782-786, 1973 and Mutat. Res. 31: 347-364, 1975).
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: crystalline
Details on test material:
Purity 99.7%

Method

Target gene:
Histidine
Species / strain
Species / strain / cell type:
other: Salmonella typhimurium: TA1535, TA1537, TA1538, TA98, TA100
Metabolic activation:
with and without
Metabolic activation system:
S9-Mix
Test concentrations with justification for top dose:
3.9, 7.8, 15.6, 31.2, 62.5, 125 µg/plate
Vehicle / solvent:
Water was used as solvent.
Controls
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Positive control substance:
other: Cyclophosphamide (250 µg/plate; TA 1535), Neutral red 25 µg/plate; TA 1537) and 2-Aminofluorene (50 µg/plate; TA 1538, TA 98 TA 100)
Details on test system and experimental conditions:
All strains had an rfa mutation (affecting membrane permeability). All strains had a uvrB deletion mutation (affecting DNA excision repair)
TA 98 and TA 100,had a plasmid pKM101 (enhancing the error-prone DNA repair system). TA 1535 and TA 100 detect base pair substitution mutations affecting the hisG46 allele. TA 1538 and TA 98 detect frameshift mutations affecting the hisD3052 allele.
Test substance was tested for mutagenicity in the reverse mutation assay on bacteria with and without metabolic activation (S9-mix prepared from the liver S9 fraction of Aroclor 1254-treated male Wistar rats). Replicate assays were conducted, each with 3 plates per test concentration.The plates were incubated at 37°C for two days; thereafter the number of revertant colonies per plate was determined by manual counting or by means of an automated colony counter. The results were expressed as means of the 3 plates.

Results and discussion

Test results
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
other: 125 µg/plate in presence of S9 and 62.5 µg/plate in absence of S9 mix.
Additional information on results:
Up to the maximum dose levels allowed by bacterial toxicity (i.e. 125 µg/plate in presence of S9 and 62.5 µg/plate in absence of S9), the numbers of revertants recorded were within the range of the negative control (distilled water); the increased numbers of revertants obtained within the positive controls confirmed the validity of the results of the present test.
Remarks on result:
other:
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

Table 1: Revertant colonies per plate in the a.first and b. second assay.

a.

Concentration [µg/plate)

Activation

Revertant colonies per plate (mean of 3 replicate plates)

TA 1535

TA 1537

TA 1538

TA 98

TA 100

Bronopol

125

+ S9

Cytotoxic

Cytotoxic

29 (reduced bacterial lawn)

Cytotoxic

Cytotoxic

- S9

Not tested

Not tested

Not tested

Not tested

Not tested

62.5

+ S9

16 (reduced bacterial lawn)

11 (reduced bacterial lawn)

28 (reduced bacterial lawn)

33 (reduced bacterial lawn)

164 (reduced bacterial lawn)

- S9

Cytotoxic

Cytotoxic

16 (reduced bacterial lawn)

Cytotoxic

Cytotoxic

31.2

+ S9

20 (reduced bacterial lawn)

9

29

39 (reduced bacterial lawn)

192

- S9

14 (reduced bacterial lawn)

8 (reduced bacterial lawn)

20 (reduced bacterial lawn)

24 (reduced bacterial lawn)

183 (reduced bacterial lawn)

15.6

+ S9

20

11

27

35

173

- S9

17 (reduced bacterial lawn)

12 (reduced bacterial lawn)

22

30

172

7.8

+ S9

21

12

28

37

163

- S9

18

12

19

29

174

3.9

+ S9

Not tested

Not tested

Not tested

Not tested

Not tested

- S9

17

11

22

29

159

Cyclophos.

250

+ S9

>500

Not tested

Not tested

Not tested

Not tested

- S9

105

Not tested

Not tested

Not tested

Not tested

Neutral Red

25

+ S9

Not tested

>500

Not tested

Not tested

Not tested

- S9

Not tested

25

Not tested

Not tested

Not tested

2-Aminofl.

50

+ S9

Not tested

Not tested

> 2000

> 2000

> 1000

- S9

Not tested

Not tested

192

212

178

Dist. water

+ S9

21

11

26

37

169

- S9

18

12

20

31

158

b.

Concentration [µg/plate)

Activation

Revertant colonies per plate (mean of 3 replicate plates)

TA 1535

TA 1537

TA 1538

TA 98

TA 100

Bronopol

125

+ S9

Cytotoxic

Cytotoxic

20 (reduced bacterial lawn)

Cytotoxic

Cytotoxic

- S9

Not tested

Not tested

Not tested

Not tested

Not tested

62.5

+ S9

20 (reduced bacterial lawn)

11 (reduced bacterial lawn)

28 (reduced bacterial lawn)

38 (reduced bacterial lawn)

171 (reduced bacterial lawn)

- S9

Cytotoxic

Cytotoxic

Cytotoxic

Cytotoxic

Cytotoxic

31.2

+ S9

24 (reduced bacterial lawn)

8

29

37 (reduced bacterial lawn)

167

- S9

14 (reduced bacterial lawn)

Cytotoxic

26 (reduced bacterial lawn)

28 (reduced bacterial lawn)

136 (reduced bacterial lawn)

15.6

+ S9

23

10

29

34

184

- S9

23 reduced bacterial lawn)

12 (reduced bacterial lawn)

24

25 (reduced bacterial lawn)

161 (reduced bacterial lawn)

7.8

+ S9

23

9

29

35

157

- S9

20

11

24

28

159

3.9

+ S9

Not tested

Not tested

Not tested

Not tested

Not tested

- S9

21

10

22

26

132

Cyclophos.

250

+ S9

>500

Not tested

Not tested

Not tested

Not tested

- S9

156

Not tested

Not tested

Not tested

Not tested

Neutral Red

25

+ S9

Not tested

>500

Not tested

Not tested

Not tested

- S9

Not tested

19

Not tested

Not tested

Not tested

2-Aminofl.

50

+ S9

Not tested

Not tested

> 2000

> 2000

> 1000

- S9

Not tested

Not tested

198

179

204

Dist. water

+ S9

23

11

29

35

168

- S9

20

10

24

27

134

Applicant's summary and conclusion