Reaction mass of stigmast-5-en-3-β-ol and stigmasta-5,22-dien-3-β-ol and (24R)-ergost-5-en-3β-ol

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Report date:

2022

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Reaction mass of (24R)-ergost-5-en-3β-ol and stigmast-5-en-3-β-ol and stigmasta-5,22-dien-3-β-ol

EC Number:

904-790-6

Molecular formula:

C28H48O; C29H50O; C29H48O

IUPAC Name:

Reaction mass of (24R)-ergost-5-en-3β-ol and stigmast-5-en-3-β-ol and stigmasta-5,22-dien-3-β-ol

Method

Target gene:

histidine

Species / strain

Species / strain 1

Species / strain / cell type:

E. coli WP2 uvr A

Species / strain 2

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Metabolic activation:

with and without

Metabolic activation system:

liver S9 fraction from rats pre-treated with phenobarbital and 5,6-benzoflavone.

Test concentrations with justification for top dose:

The test item MIXTURE OF PHYTOSTEROLS was assayed in the toxicity test at a maximum
concentration of 5000 µg/plate and at four lower concentrations spaced at approximately
half-log intervals: 1580, 500, 158 and 50.0 µg/plate. Precipitation of the test item, from
severe to slight, which did not interfere with the scoring, was observed at higher dose
levels both in the absence and presence of S9 metabolic activation. No toxicity or relevant
increases in revertant numbers were observed with any tester strain, at any dose level, in
the absence or presence of S9 metabolism.
On the basis of solubility results obtained in the preliminary toxicity test, in Main Assay I,
using the plate incorporation method, the test item was assayed with all tester strains at
the following dose levels: 1500, 750, 375, 188 and 93.8 µg/plate

Vehicle / solvent:

acetone

Results and discussion

Test results

Species / strain:

other: all treated strains

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Additional information on results:

No toxicity was observed at any dose level with any tester strain, in the absence or presence
of S9 metabolic activation.
As no relevant increase in revertant numbers was observed at any concentration tested, a
pre-incubation step was included for all treatments of Main Assay II. Due to the acetone
toxicity, the volume of vehicle or test item solution used in the preparation of each plate
was reduced to 20 µL, hence the test item was assayed at the maximum concentration of
1000 µg/plate and at five lower dose levels spaced by a factor of two: 500, 250, 125, 62.5 and
31.3 µg/plate.
Precipitation of the test item, from moderate to slight, which did not interfere with the
scoring, was observed at higher dose levels both in the absence and presence of S9 metabolic
activation. No toxicity or relevant increase in the number of revertant colonies was observed
in the pre-incubation assay, at any dose level, with any tester strain/treatment condition
combinations.
The test item did not induce two-fold increases in the number of revertant colonies in the
plate incorporation or pre-incubation assay, at any dose level, in any tester strain, in the
absence or presence of S9 metabolism.

Applicant's summary and conclusion

Conclusions:

The test item MIXTURE OF PHYTOSTEROLS does not induce reverse mutation in Salmonella typhimurium or Escherichia coli in the absence or presence of S9 metabolism, under the reported experimental conditions.