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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:
15-20 March 2000
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: According to GLP and OECD 471, with one exception: negative test result not confirmed in an independent repeat test. Test performed with a surrogate which has a comparable composition.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2000
Report Date:
2000

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
negative test result not confirmed in an independent repeat test
Principles of method if other than guideline:
The test was performed using the plate incorporation assay.
GLP compliance:
yes (incl. certificate)
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): Gistex Standard Powder AGGL
- Molecular formula (if other than submission substance): no data
- Molecular weight (if other than submission substance): no data
- Smiles notation (if other than submission substance): no data
- InChl (if other than submission substance): no data
- Structural formula attached as image file (if other than submission substance): no data
- Substance type: powder
- Physical state: solid
- Analytical purity: no data
- Impurities (identity and concentrations): no data
- Composition of test material, percentage of components: no data
- Isomers composition: no data
- Purity test date: no data
- Lot/batch No.: PHS2 A04
- Expiration date of the lot/batch: 4 August 2000
- Radiochemical purity (if radiolabelling): not relevant
- Specific activity (if radiolabelling): not relevant
- Locations of the label (if radiolabelling): not relevant
- Expiration date of radiochemical substance (if radiolabelling): not relevant
- Stability under test conditions: no data
- Storage condition of test material:
- Other:

Method

Target gene:
Reversion from his- to his+

Species / strain
Species / strain / cell type:
other: TA-1535, TA-1537, TA-1538, TA-98, TA-100 & E. coli WP2 uvrA
Metabolic activation:
with and without
Metabolic activation system:
S9 mix from livers of Aroclor 1254 induced male rats
Test concentrations with justification for top dose:
62, 185, 556, 1667 and 5000 µg/plate (with and without S9)
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: water
- Justification for choice of solvent/vehicle: the test substance was soluble in water up to the highest test concentration
Controls
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: without S9: sodium azide (TA-1535, TA-100), 2-nitrofluorene (TA-98), 9-aminoacridine (TA-1537), N-ethyl-N-nitrosourea (WP2 uvrA); with S9: 2-aminoanthracene (all strains except TA 1537), benzo(a)pyrene (TA1537)
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation)
DURATION
- Exposure duration: 72 hours
NUMBER OF REPLICATIONS: 3 plates per strain per concentration (with S9 and without S9)
DETERMINATION OF CYTOTOXICITY
- Method: reduction in number of revertant colonies and/or clearing of background lawn of bacterial growth
Evaluation criteria:
The assay was considered valid if the mean colony counts of the control are within acceptable ranges and if the results of the positive control meet the criteria for a positive response.
A response was considered positive if the mean number of revertant colonies on the test plates is increased two-fold or more compared to that on the negative control plates.
A test substance was considered to be mutagenic if a concentration related increase or if a reproducible positive response is observed.
Statistics:
None.

Results and discussion

Test results
Species / strain:
other: all tested strains
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
not specified
Positive controls validity:
valid
Additional information on results:
TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: none observed
- Other confounding effects: none
RANGE-FINDING/SCREENING STUDIES: not relevant

COMPARISON WITH HISTORICAL CONTROL DATA: the mean colony counts of the controls were within acceptable ranges and the results of the positive control met the criteria for a positive response.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

The results are summarised in the table below, which shows the mean number of revertants of 3 plates.

dose

TA1535

TA1537

TA98

TA100

E. coli

(ug/plate)

-S9

+S9

-S9

+S9

-S9

+S9

-S9

+S9

-S9

+S9

0

14

18

7

14

29

40

162

145

31

34

62

15

13

9

19

29

40

128

136

25

34

185

12

14

7

12

26

37

122

132

22

30

556

11

11

10

17

35

57

133

132

22

35

1667

22

21

12

17

33

51

145

179

26

31

5000

24

19

6

17

35

55

146

194

25

30

pos cont.

1068

294

907

226

1113

608

1004

1464

274

1073

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

In an Ames test (plate incorporation assay) according to OECD 471, the test substance was negative in all 5 tester strains in the presence and absence of metabolic activation (S9 mix from livers of Aroclor 1254 induced rats). The negative result was not confirmed in an independent repeat test.