Kombucha

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)

Justification for type of information:

Please refer to the Read-across Justification provided in IUCLID section 13

Data source

Reference

Title:

Unnamed

Year:

2002

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Principles of method if other than guideline:

This test was conducted to satisfy, in part, the requirements of the International Organization for Standardization (ISO) 10993, Part 3: Test for Genotoxicity, Carcinogenicity and Reproductive Toxicity.

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Fermentation product of sucrose and Theaceae Camellia Camellia sinensis leaves with a variable symbiosis of bacteria and yeast, of including bacteria of Acetoacteraceæ Acetobacter and Gluconobacter genus, and yeasts of Saccharomycetaceae family

Molecular formula:

Not applicable

IUPAC Name:

Fermentation product of sucrose and Theaceae Camellia Camellia sinensis leaves with a variable symbiosis of bacteria and yeast, of including bacteria of Acetoacteraceæ Acetobacter and Gluconobacter genus, and yeasts of Saccharomycetaceae family

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:

valid

Untreated negative controls validity:

not examined

True negative controls validity:

not examined

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:

valid

Untreated negative controls validity:

not examined

True negative controls validity:

not examined

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:

valid

Untreated negative controls validity:

not examined

True negative controls validity:

not examined

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:

valid

Untreated negative controls validity:

not examined

True negative controls validity:

not examined

Positive controls validity:

valid

Test results 5

Key result

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

True negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

Salmonella typhimurium strains TA98, TA100, TA1535 and TA1537, and Escherichia coli strain WP2uvrA exhibited genetic characteristics pertaining to this assay. No significant inhibition was observed.

In no case there a 2-fold or greater increase in the number of revertants of tester strains TA98, TA100, TA1535 and TA1537, and WP2uvrA in the presence of a DMSO test article solution. Each positive control mean exhibited at least a 3-fold increase over the respective mean of the S. typhimurium tester strain employed and at least 2-fold increase over th respective mean of the E. coli tester strain.

Applicant's summary and conclusion

Conclusions:

Under the conditions of this assay, the product KOM 02180 was considered to be non-mutagenic to Salmonella typhimurium strains TA 98, TA100, TA1535 and TA1537, and to Escherichia coli strain WP2uvrA.

Executive summary:

A Salmonella typhimurium and Escherichia coli reverse mutation standard plate incorporation study was conducted to evaluate whether a the test article KOM 02180 (undiluted application), would cause mutagenic changes in the average number of the revertants for histidine-dependent Salmonella typhimurium strains TA98, TA100, TA1535 and TA1537, and in tryptophan-dependent Escherichia coli strain WP2uvrA in the presence and absence of S9 metabolic activation.

The test article solution was found to be non-inhibitory to growth of tester strains TA98, TA100, TA1535, TA1537, and WP2uvrA. Separate tubes containing 2 ml of molten top agar supplemented with histidine-biotin solution for the S. typhimurium strains and with tryptophan for E.coli strain were inoculated with 0.1 ml of culture for each of five tester strains, and 0.1 ml of the test article solution. A 0.5 ml aliquot of sterile Water for Injection (SWI) or S9 homogenate, simulating metabolic activation, was added when necessary.

The mixture was poured across triplicate Minimal E plates. Parallel testing was also conducted with a negative control and five positive controls. The mean number of revertants of the triplicate test plates was compared to the mean number of revertants of the triplicate negative control plates for each of the five tester strains employed. The means obtained for the positive controls were used as points of reference.

Under the conditions of this assay, the product KOM 02180 was considered to be non-mutagenic to Salmonella typhimurium strains TA 98, TA100, TA1535 and TA1537, and to Escherichia coli strain WP2uvrA.