Hexachloroplatinic acid

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:

4 September - 26 September 2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study conduced to GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2004

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Hexachloroplatinic acid (hydrate)

Cas Number:

26023-84-7

Molecular formula:

K2PtCl6

IUPAC Name:

Hexachloroplatinic acid (hydrate)

Details on test material:

- Name of test material (as cited in study report): Hexachloroplatinum(IV)-solution

- Substance type:
- Physical state: liquid
- Analytical purity:
- Impurities (identity and concentrations):
- Composition of test material, percentage of components: 25% Pt
- Isomers composition:
- Purity test date: 2003-08-08
- Lot/batch No.: 2700/76-03
- Expiration date of the lot/batch: 31 July 2004

- Stability under test conditions: not stated
- Storage condition of test material: room temperature; opaque plastic bottle
- Other:

Method

Target gene:

Histidine (S. typhimurium) and tryptophan (E.coli) loci

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:

S9 from male Sprague-Dawley rats given prior treatment with phenobarbital abd betanaphthoflavone

Test concentrations with justification for top dose:

Two main experiments were performed:

In experiment 1 (plate incorporation method) the test item was assayed in TA1535 at 2.5, 5.0, 10.0, 20.0, 40.0 and 80.0 ug/plate, and in TA1537, TA98, TA100 and WP2uvra at 1.25, 2.5, 5.0, 10.0, 20.0 and 40.0 ug/plate (without S9). In all five strains it was tested at 10.0, 20.0, 40.0, 80.0, 160.0 ug/plate (with S9); TA98 and TA100 were also tested at 320 ug/plate (with S9).

In experiment 2 (pre-incubation method) the test item was assayed in TA1535, TA98 and TA100 at 0.313, 0.625, 1.25, 2.5, 5.0 and 10.0 ug/plate (in the absence of S9); TA100 was also tested at 20.0 and 40.0 ug/plate. TA1537 was tested at 0.625, 1.25, 2.5, 5.0, 10.0, and 20.0 ug/plate (without S9).In the presence of S9, all four Salmonella strains were tested at 2.5, 5.0, 10.0, 20.0, 40.0 and 80.0 ug/plate; TA1537 and TA100 were also tested at 1.25 and 160 ug/plate, and TA98 additionally at 0.625 ug/plate (with S9). WP2uvra was not used in experiment 2.

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: sterile distilled water
- Justification for choice of solvent/vehicle: soluble at 50.0 mg/ml. Since 100 ul of test item soluition used in the preparation of each plate, this permitted a max. conc. of 5000 ug/plate in toxicity test.

Controls

Controls 1

Untreated negative controls:

yes

Remarks:

Dimethylsulphoxide (DMSO)

Negative solvent / vehicle controls:

yes

Remarks:

Sterile distilled water

Positive controls:

yes

Positive control substance:

methylmethanesulfonate

Controls 2

Positive controls:

yes

Positive control substance:

sodium azide

Controls 3

Positive controls:

yes

Positive control substance:

9-aminoacridine

Controls 4

Positive controls:

yes

Positive control substance:

2-nitrofluorene

Controls 5

Positive controls:

yes

Positive control substance:

other: 2-Aminoanthracene

Details on test system and experimental conditions:

Salmonella typhimurium strains TA1535, TA1537, TA100, TA98 and Escherichia coli WP2uvrA were used in experiment 1 (plate incorporation method) and all four S. typhimurium strains in experiment 2 (pre-incubation method), excluding E. Coli WP2uvrA. 3 replicate plates. Dose range finding study, and two main experiments (1 and 2) only.

Evaluation criteria:

For the test item to be considered mutagenic, two-fold (or more) increases in mean revertant numbers must be observed at two consecutive dose-levels or at the highest practicable dose-level only. In addition, there must be evidence of a dose-response relationship showing increasing numbers of mutant colonies with increasing dose-levels.

Number of cells evaluated per dose group not given in report.

Statistics:

Not reported

Results and discussion

Test results

Test results 1

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

positive

Remarks:

dose-related increases, at least two fold

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with

Genotoxicity:

ambiguous

Remarks:

dose-related increase in revertant numbers (experiments 1 & 2)

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 3

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with

Genotoxicity:

ambiguous

Remarks:

dose-related increase in revertant numbers (experiments 1 & 2)

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 4

Species / strain:

S. typhimurium TA 100

Metabolic activation:

without

Genotoxicity:

negative

Remarks:

experiments 1 & 2

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 5

Species / strain:

S. typhimurium TA 98

Metabolic activation:

without

Genotoxicity:

negative

Remarks:

experiments 1 & 2

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 6

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Remarks:

experiments 1 & 2

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 7

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Remarks:

experiments 1 & 2

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
positive

In an OECD Test Guideline 471 study, to GLP, hexachloroplatinum(IV) solution induced reverse mutations in Salmonella typhimurium strains TA98 and TA100 and in Escherichia coli WP2 uvrA under the experimental conditions.

Executive summary:

In an OECD Test Guideline 471 study, conducted according to GLP, hexachloroplatinum(IV) solution was assessed for its ability to induce gene mutations in strains of Salmonella typhimurium (TA1535, TA1537, TA98, TA100) and Escherichia coli (WP2 uvrA). The test was performed in two independent experiments, with dose levels determined following an initial toxicity test, both in the absence and presence of metabolic activation (S9) using liver fraction from rats pre-treated with phenobarbitone and beta-naphthoflavone.

 

In experiment 1, dose-related increases in revertant numbers, which were at least two-fold the control values, were observed in WP2 uvrA both in the absence and presence of S9. Dose-related increases in revertant numbers were also observed in TA98 and TA100 tester strains in the presence of S9.

 

In experiment 2, conducted using the four S. typhimurium strains, large dose-related increases in revertant numbers were observed at higher dose levels in TA98 in the presence of S9. Dose-related and reproducible increases in revertant numbers were also observed in TA100 tester strain in the presence of S9. Although these increases did not reach two-fold the control values they were considered clear evidence of a mutagenic effect.

 

It was concluded that hexachloroplatinum(IV) solution was mutagenic in S. typhimurium strains TA98 and TA100 and in E. coli WP2 uvrA under the experimental conditions.