Silver

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in mammalian cells

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

no data avaialble

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: well documented publication, methods described in detail and results presented adequately

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Effect of silver compounds on in vitro cultured mammalian cells. II.study of gentoxicity and the effect of diamminesilver tetraborate on macromolecular synthesis of V79cells

Author:

Dusinska, M., Slamenova, D.

Year:

1990

Bibliographic source:

Biologia 45, 211-218

Reference 2

Reference Type:

publication

Title:

Occurrence of induced 6-thioguanine-resistant colonies in synchronized V79 cells after treatment with ftorafur. Effects of the S9 fraction.

Author:

Slamenová, D.; et al.

Year:

1984

Bibliographic source:

Neoplasma 31, 339-346

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

In the present study the effect of diammine silver tetraborate (DSTB) on V79 hamster cells were reported.

GLP compliance:

no

Type of assay:

mammalian cell gene mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

diammine silver tetraborate

IUPAC Name:

diammine silver tetraborate

Details on test material:

- Test substance: Diamminesilver tetraborate (silver salt)
- Molecular formular: [Ag(NH3)2] [B4O5(OH)4]
- Physical state: solid
- Producer: Slovakofarma, Hlohovec, Czechoslovakia
No further details are given.

Method

Target gene:

hprt locus

Species / strain

Species / strain / cell type:

Chinese hamster lung fibroblasts (V79)

Details on mammalian cell type (if applicable):

Diploid V79 hamster cells were used.
- Type and identity of media: Eagle's minimum essential medium (MEM)
Cells were incubated for 24 hours.

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with and without

Metabolic activation system:

S9-mix

Test concentrations with justification for top dose:

- without metabolic activation: 0.2, 0.5, 1.0 and 2.0 µg/mL;
- with metabolic activation: 0.2, 0.5, 1.0 and 2.0 µg/mL.

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: phosphate buffered saline (PBS): The concentration of the stock solution was 63 mg/mL in water. The substance was diluted in PBS.
- Justification for choice of solvent/vehicle: no data

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

V79 cells kept for 60 minutes in PBS with or without S9-mix were used as controls.

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 3,4-benzo(a)pyrene; 10 µg/mL (dissolved in PBS, treated for 120 minutes)

Remarks:

with and without metabolic activation

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium

DURATION
- Exposure duration: 60 minutes in PBS
- Expression time (cells in growth medium): 8 days
- Selection time (if incubation with a selection agent):10 days; The colonies were stained and evaluated on day 10 after plating.

SELECTION AGENT (mutation assays): 6-thioguanine (6-TGr; 5 µg/mL)
STAIN (for cytogenetic assays): methylene blue

NUMBER OF REPLICATIONS: three separate experiments per concentration


NUMBER OF CELLS EVALUATED: At each concentration of DSTB and 3,4-benzo(a)pyrene 2.5 x 10^6 cells were evaluated for mutants.
EVALUATION: The number of 6-TGr mutations per 1x10^5 viable cells was scored.

DETERMINATION OF CYTOTOXICITY
- Method: colony forming ability:
Treated cells and control cells were wahed, trypsinised and plated in Petri dishes for estimation of cytotoxicity. The colonies were stained and evaluated on day 7 after plating.

OTHER: The assay for detection of 6-TGr mutations was performed as described previously by Slamenová et al. 1984.

Evaluation criteria:

no data

Statistics:

no data

Results and discussion

Test results

Test results 1

Species / strain:

Chinese hamster lung fibroblasts (V79)

Metabolic activation:

without

Genotoxicity:

negative

Remarks:

The test item induced no gene mutation.

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

A cytotoxic effect of about 27-91% was observed at concentrations of 0.2 to 2.0 µg/mL (for details see table in the technical dossier).

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 2

Species / strain:

Chinese hamster lung fibroblasts (V79)

Metabolic activation:

with

Genotoxicity:

negative

Remarks:

The test item induced no gene mutation.

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

A cytotoxic effect of about 17-29% was observed at concentrations of 0.2 to 2.0 µg/mL (for details see table in the technical dossier).

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

No further details are given.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

Test for mutagenicity showed that the test item, diamminesilver tetraborate, did not induce gene mutation in hamster cells.