Sodium hydrogen glutamate

Genetic toxicity: in vitro

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:

June 30 - December 6, 2006

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study has been performed according to OECD guidelines and according to GLP principles.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: Guidelines for Designation of Food Additives and for Revision of Standards for Use of Food Additives" (Japanese Ministry of Health and Welfare, Eika No. 29, March 22, 1996)

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: Guideline for Genotoxicity Tests on Drugs" (Pharmaceutical and Medical Safety Bureau, Japanese Ministry of Health and Welfare, Notification Iyakushin No. 1604, November 1, 1999)

Test guideline 3

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

Principles of method if other than guideline:

US Food and Drug Administration Redbook 2000: Toxicological Principles for the Safety of Food Ingredients IV.C.l.a. Bacterial Reverse Mutation Test"
(July 7, 2000). The study conduct also complied with OECD 471.

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Sodium hydrogen glutamate

EC Number:

205-538-1

EC Name:

Sodium hydrogen glutamate

Cas Number:

142-47-2

Molecular formula:

C5H8NNaO4

IUPAC Name:

sodium hydrogen 2-aminopentanedioate

Details on test material:

- Name of test material (as cited in study report): monosodium L-glutamate monohydrate produced by a new method
- Substance type: hydrated form
- Physical state: white powder
- Stability under test conditions: stable
- Storage condition of test material: At room temperature under shading from light and well-closed conditions

Method

Target gene:

Histidine gene in S. typhimurium
Tryptophan gene in E. coli

Species / strain

Species / strain 1

Species / strain / cell type:

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

Species / strain 2

Species / strain / cell type:

E. coli WP2 uvr A

Metabolic activation:

with and without

Metabolic activation system:

phenobarbital and 5,6-benzoflavone induced rat liver S9 mix

Test concentrations with justification for top dose:

Preliminary test: 1.50, 5.00, 15.0, 50.0, 150, 500, 1500 and 5000 μg/plate
First and second test: 313, 625, 1250, 2500 and 5000 μg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: water for injection lP
- Justification for choice of solvent/vehicle: test substance is soluble in water (solubility: 740 mg/mL, 25°C)

Controls

Controls 1

Untreated negative controls:

yes

Remarks:

water for injection lP

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

without S9 mix

Migrated to IUCLID6: 0.5 ug/plate in water for injection JP for TA1535

Controls 2

Positive control substance:

9-aminoacridine

Remarks:

without S9 mix

Migrated to IUCLID6: 80 ug/plate in DMSO for TA1537

Controls 3

Positive control substance:

other: 2-(2-Furyl)-3-(5-nitro-2-furyl) acrylamide 0.01 ug/plate in DMSO for TA100 and WP2uvrA and 0.1 ug/plate in DMSO for TA98

Remarks:

without S9 mix

Controls 4

Positive control substance:

benzo(a)pyrene

Remarks:

with S9 mix

Migrated to IUCLID6: 5 ug/plate in DMSO for TA1537, TA98 and TA100

Controls 5

Positive control substance:

other: 2-aminoanthracene 2 ug/plate in DMSO for TA1535 and 10 ug/plate for WP2uvrA

Remarks:

with S9 mix

Details on test system and experimental conditions:

METHOD OF APPLICATION: preincubation method;
DURATION
- Exposure duration: 48 h
NUMBER OF REPLICATIONS: doses of the test substance were tested single in each strain in the dose-finding test.
In the mutagenicity tests doses of the test substance were tested in triplicate in each strain. Two independent experiments were conducted.
DETERMINATION OF CYTOTOXICITY
- Method: the reduction of the bacterial background lawn, the increase in the size of the microcolonies and
the reduction of the revertant colonies
OTHER EXAMINATIONS:
- Other: precipitation of test substance

Evaluation criteria:

The results were judged to be positive, if the mean number of revertant colonies for each dose with the test article increased twice or more than
that in the negative control, and dose dependency or reproducibility were observed in the increase of revertant colonies, at least in one strain out
of the five strains used with or without S9 mix.

Results and discussion

Test results

Test results 1

Species / strain:

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

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

RANGE-FINDING/SCREENING STUDIES:
No toxicity and mutagenicity was observed up to concentrations of 5000 μg/plate
COMPARISON WITH HISTORICAL CONTROL DATA:
Positive results were confirmed in the positive control groups, and the mean number of revertants in the positive and negative controls was within the fluctuation range (mean ± 3 S.D.) of the historical control values. Thus, the effectiveness ofthis test system was confirmed.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative with and without metabolic activation

From these results, it is concluded that the test article, Monosodium L-glutamate monohydrate produced by a new method, has no mutagenic activity (negative) in this test system.