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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:
18 March 1987 to 3 April 1987
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP compliant, guideline study, available as unpublished report, no restrictions, fully adequate for assessment
Cross-reference
Reason / purpose:
reference to same study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1987
Report Date:
1987

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
A minimum of 5 strains were not tested. The test did not include S typhimurium TA102 or E.coli.
Principles of method if other than guideline:
not applicable
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Target gene:
not applicable
Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Metabolic activation system:
Aroclor 1254 induced rat liver S9
Test concentrations with justification for top dose:
0.08, 0.31, 1.2, 4.9, 19.5, 78.1, 312.5, 1250, 5000 µg/0.1 mL (toxicity test)
20, 78, 313, 1250 and 5000 µg/0.1 mL (mutagenicity test). Analytical purity: 98.3%
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: acetone, the vehicle was chosen due to its solvent properties and low toxicity to the bacteria.
Controlsopen allclose all
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Positive control substance:
other: daunorubicin-HCl
Remarks:
TA98, 5 and 10 µg/0.1 mL, without S9
Positive control substance:
4-nitroquinoline-N-oxide
Remarks:
TA100, 0.125 and 0.25 µg/0.1 mL, without S9
Positive control substance:
sodium azide
Remarks:
TA1535, 2.5 and 5 µg/0.1 mL, without S9
Positive control substance:
other: 9(5)aminoacridine hydrochloride monohydrate
Remarks:
TA1537, 50 and 100 µg/0.1 mL, without S9
Positive control substance:
other: 2-aminoanthracene
Remarks:
TA98, TA100 and TA1537, 5 µg/0.1 mL, with S9
Positive control substance:
cyclophosphamide
Remarks:
TA1535, 250 µg/0.1 mL, with S9
Details on test system and experimental conditions:
METHOD OF APPLICATION: in medium; in agar (plate incorporation)
- Each plate contained approximately 20 mL mimimum agar plus salts and glucose; 0.1 mL of a solution of the test substance or vehicle and 0.1 mL of bacterial culture in 2.0 mL of soft agar.
- The soft agar composed of 100 mL 0.6% agar with 0.6% NaCl and 10 mL of a solution of 0.5 mM 1-histidine and 0.5 mM +biotin.
- With metabolic activation, 0.5 mL S9 was also added.

DURATION
- Incubation: 48 hrs at 37±1.5°C in darkness

NUMBER OF REPLICATIONS: 3
Evaluation criteria:
The test substance is considered positive if one or more of the following conditions are met:
- at least a reproducible doubling of the mean number of revertants per plate above that of the negative control at any concentration level for one or more of the following strains: TA98, TA1535 and TA1537
- a reproducible increase of the mean number of revertants per plate for any concentration above that of the negative control by at least a factor of 1.5 for strain TA100.
- a concentration-related effect should be demonstrable
Statistics:
not applicable

Results and discussion

Test results
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Positive controls validity:
valid

Any other information on results incl. tables

Due to a growth-inhibiting effect of the test substance in the repeat experiments with and without S9, the number of back-mutant colonies was reduced with strain TA1537 at the upper concentrations.

At 1250 and 5000 µg/0.1 mL the test substance precipitated in soft agar.

Table 1: Test 1 without S9

 

TA98

TA100

TA1535

TA1537

Control

29

95

12

6

20 µg/0.1 mL

34

98

12

6

78 µg/0.1 mL

20

88

10

7

313 µg/0.1 mL

16

110

10

11

1250 µg/0.1 mL

25

103

10

5

5000 µg/0.1 mL

17

97

11

5

Table 2: Test 1 with S9

 

TA98

TA100

TA1535

TA1537

Control

41

131

18

17

20 µg/0.1 mL

44

131

14

26

78 µg/0.1 mL

43

128

15

14

313 µg/0.1 mL

41

129

17

15

1250 µg/0.1 mL

45

131

13

16

5000 µg/0.1 mL

41

126

17

13

Table 3: Test 2 without S9

 

TA98

TA100

TA1535

TA1537

Control

27

129

10

7

20 µg/0.1 mL

27

122

15

5

78 µg/0.1 mL

24

114

16

6

313 µg/0.1 mL

27

94

16

7

1250 µg/0.1 mL

22

88

14

3

5000 µg/0.1 mL

17

80

12

2

Table 4: Test 2 with S9

 

TA98

TA100

TA1535

TA1537

Control

34

129

14

13

20 µg/0.1 mL

32

131

12

10

78 µg/0.1 mL

36

158

23

10

313 µg/0.1 mL

40

147

14

8

1250 µg/0.1 mL

43

159

15

12

5000 µg/0.1 mL

45

126

9

6

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative with metabolic activation
negative without metabolic activation

There was no evidence of the induction of point mutations by CGA154281 technical, with or without S9 mix in the strains of S.typhimurium used in these experiments.
Executive summary:

In a bacterial mutagenicity study using S.typhimurium strains TA98, TA100, TA135 and TA1537 with 20, 78, 313, 1250 and 5000 µg CGA154281/0.1 mL, with and without S9 microsomal activation, there was no evidence of the induction of point mutations.