Saccharides from Saccharomyces Cerevisiae

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

January February 1997

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Report date:

1997

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

not specified

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 472 (Genetic Toxicology: Escherichia coli, Reverse Mutation Assay)

Deviations:

not specified

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Saccharides from Saccharomyces Cerevisiae

EC Number:

946-843-6

IUPAC Name:

Saccharides from Saccharomyces Cerevisiae

Test material form:

liquid

Details on test material:

yellow liquid

Method

Target gene:

Histidine

Species / strain

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2

Details on mammalian cell type (if applicable):

Not applicable

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with and without

Metabolic activation system:

10% S9 : S9-mix from the livers of male Sprague Dawley rats

Test concentrations with justification for top dose:

5000, 1580, 500, 158 and 50 µg/plate. Precipitation of the test product was noted at the highest-dose level.
No evidence of toxicity was observed at any dose-level tested with any tester strain, in the absence or presence of S9 metabolism. On the basis of these results, the same concentration of 5000 µg/plate was selected for the main assay

Vehicle / solvent:

DMSO

Controls

Controls 1

Untreated negative controls:

yes

Remarks:

untreated and solvent vehicle controls

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

9-aminoacridine

2-nitrofluorene

sodium azide

methylmethanesulfonate

Remarks:

without S9

Controls 2

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene

Remarks:

with S9

Details on test system and experimental conditions:

SOURCE OF TEST SYSTEM
- Bacteria used in the test was obtained from University of California (USA) and Life Science Research, Occold, Suffolk, UK
METHOD OF APPLICATION: in agar (plate incorporation); preincubation
DURATION
- Preincubation period: 37 °C for 20 minutes
- Exposure duration: Plates were incubated at 37 ± 1 °C for 72 h

Evaluation criteria:

For a test product considered mutagenic, two fold (or more) increases in mean revertant number must be observed at two consecutive dose-levels or at the highest practicle dose level only. In addition, there must be evidence of a dose-response relationship showing increasing number of mutant colonies with increasing dose-level. The effect must be reproducted in an independant experiment. The sterility of the S9 system and the test product solutions was confirmed by rhe absence of colonies on additional agar plates spread separately with these solutions. Marked increases in revertant numbers were obtained in these tests following treatment with the positive controls, indicating that the assay system was responded correctly

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 3

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 4

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 5

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

not specified

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Applicant's summary and conclusion

Conclusions:

Two experiment were performed, one using a plate incorporation method, the other using the pre-incubation method. The test product was assayed at a maximum dose level of 5000µg/plate and four lower doser-levels, separately by to fold dilutions: 2500, 1250, 625 and 313 µg/plate.
The test product did not induce two fold increases in the number of revertant colonies in the plate incorporation or pre-incubation method, at any dose-level, in any tester strain, in the absence or presence of S9 dependent metabolism.
The test item is not mutagenic toward Salmonella typhimurium and Escherichia Coli under the reported conditions.

Executive summary:

In a reverse gene mutation assay in bacteria, performed according to the OECD Guideline 471 and 472 and in compliance with GLP, strains of Salmonella typhimurium (TA1535, TA1537, TA98, TA100 and E.Coli WP2) were exposed to test item.

Two experiment were performed, one using a plate incorporation method, the other using the pre-incubation method. The test product was assayed at a maximum dose level of 5000µg/plate and four lower doser-levels, separately by to fold dilutions: 2500, 1250, 625 and 313 µg/plate.

The test product did not induce two fold increases in the number of revertant colonies in the plate incorporation or pre-incubation method, at any dose-level, in any tester strain, in the absence or presence of S9 dependent metabolism.

The test item is not mutagenic toward Salmonella typhimurium and Escherichia Coli under the reported conditions.