Enzymatic hydrolysis products of Sargassum hemiphyllum, ext.

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

Year:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Enzymatic hydrolysis products of Sargassum hemiphyllum, Sargassum, Sargassaceae.

Molecular formula:

Not applicable (a generic molecular formula cannot be provided for this specific UVCB substance)

IUPAC Name:

Enzymatic hydrolysis products of Sargassum hemiphyllum, Sargassum, Sargassaceae.

Test material form:

solid: particulate/powder

Method

Species / strain

Species / strain / cell type:

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

Test concentrations with justification for top dose:

In phase A, Salmonella typhimurium TA100 was exposed to 5 different cocentrations of test substance (C1-C5), prepared with a 10 dilution factor, As cytotoxicity may vary in the presence of metabolic activation systems, the test was carried out in presence and in absence of S9 (-S9; +S9). The highest concentration (C1) was 5 mg/plate, the highest allowed in the test. The solution resulted dissolved.

In phase B, the 4 remaining bacteria strains were exposed to 5 different concentrations (C1-C5) of test substance prepared with a 10 dilution factor, in presence and in absence of a metabolic activation system (-S9; +S9). The concentrations were selected according to the preliminary cytotoxicity test. Since no cytotoxicity was observed at 5 mg.plate the highest concentration allowed in the assay, this solution was used as the first concentration (C1) to test in phase B (AMES test).

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

no

True negative controls:

no

Positive controls:

yes

Positive control substance:

4-nitroquinoline-N-oxide

9-aminoacridine

2-nitrofluorene

other: Sodium Azide; Nitrofurantoine; 4-Nitro-1,2-phenilendiammine

Results and discussion

Test results

Test results 1

Key result

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

not valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

not valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 3

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

not valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 4

Key result

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

not valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 5

Key result

Species / strain:

E. coli WP2 uvr A pKM 101

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

not valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Applicant's summary and conclusion

Conclusions:

Positive results from the bacterial reverse mutation test indicate that a substance induses point mutations by base substitutions or frameshifts in the genome of either Salminella typhimurium and.or Escherichia coli.
Negative results indicate that under the test conditions, the test substance is not mutagenic in the tested species.
On the basis of the results obtained, it can be concluded that, under the test conditions applied, the test item "Sargassum Extract powder" is considered not to be mutagenic.