Tetraammineplatinum (II) diacetate

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

In a well-conducted OECD Test Guideline 471 study, tetraammineplatinum(II) diacetate was mutagenic in Salmonella typhimurium strains TA98 and TA1537 and Escherichia coli strain WP2uvrA when tested at up to 5 mg/plate in the presence and absence of metabolic activation (Verspeek-Rip, 2004).

 

In an OECD Test Guideline 476 mouse lymphoma assay, tetraammineplatinum(II) hydrogen carbonate induced statistically significant and dose-related increases in the mutant frequency at the tk +/- locus in L5I78Y cells in the presence and absence of metabolic activation, and was considered to be mutagenic under the conditions of the test. However, it was suggested that the mutagenic response was possibly due, or partly due, to a reaction between the test material and the vehicle (DMSO) (Durward, 1998a). In a repeat of this assay, with water as the vehicle, tetraammineplatinum(II) hydrogen carbonate induced a statistically significant dose-related increase in the mutant frequency in L5178Y mouse lymphoma cells in the presence of metabolic activation (Durward, 1998b).

 

More recently, in an OECD Test Guideline 490 in vitro mammalian cell gene mutation assay, to GLP, tetraammine platinum dichloride induced mutations at the tk locus of L5178Y mouse lymphoma cells when tested at up to cytotoxic concentrations for 3 hours in the absence and presence of S9 and for 24 hours in the absence of S9 (Lloyd, 2017).

 

In an OECD Test Guideline 473 study, conducted to GLP, tetraammineplatinum(II) diacetate did not induce chromosome aberrations in Chinese hamster ovary cells in vitro, both in the absence and presence of metabolic activation (Ciliutti et al., 2007). As part of the same study, tetraammineplatinum(II) diacetate did not induce chromosome aberrations in Chinese hamster ovary cells in vitro, in the presence of metabolic activation (Ciliutti et al., 2008).

Link to relevant study records

Reference

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:

24 to 9 September 2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Guideline study, to GLP

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

substance was mixed with 3 ml surface agar, whereas the guideline recommends 2 ml

Qualifier:

according to guideline

Guideline:

EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Species / strain / cell type:

other: S. typhimurium TA98, TA100, TA1535, TA1537 and E. coli WP2uvrA

Metabolic activation:

with and without

Metabolic activation system:

Aroclor 1254-induced S9 microsomal fraction obtained from the livers of male Wistar rats

Test concentrations with justification for top dose:

In a dose-finding assay, concentrations of 3, 10, 33, 100, 333, 1000, 3330 and 5000 µg per plate were tested in triplicate on TA100 and WP2uvrA, with and without metabolic activation. Both the mutagenic and cytotoxic effects of the test material on these strains was analysed. As no cytotoxic potential was observed, subsequent mutagenicity testing on strains TA98, TA1535 and TA1537 used concentrations of 100, 333, 1000, 3330 and 5000 µg platinum(2+) tetraamimine (SP-4-1) diacetate per plate (with and without metabolic activation).

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: Milli-Q water

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

Milli-Q water

True negative controls:

no

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

Applied to S. typhimurium strain TA1535, without metabolic activation, only (at 5 µg per plate)

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

Milli-Q water

True negative controls:

no

Positive controls:

yes

Positive control substance:

9-aminoacridine

Remarks:

Applied to S. typhimurium strain TA1537, without metabolic activation, only (at 60 µg per plate) Migrated to IUCLID6: in Milli-Q water

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

Milli-Q water

True negative controls:

no

Positive controls:

yes

Positive control substance:

2-nitrofluorene

Remarks:

Applied to S. typhimurium strain TA98, without metabolic activation, only (at 10 µg per plate) Migrated to IUCLID6: in DMSO

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

Milli-Q water

True negative controls:

no

Positive controls:

yes

Positive control substance:

methylmethanesulfonate

Remarks:

Applied to S. typhimurium strain TA100, without metabolic activation, only (at 650 µg per plate) Migrated to IUCLID6: in DMSO

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

Milli-Q water

True negative controls:

no

Positive controls:

yes

Positive control substance:

4-nitroquinoline-N-oxide

Remarks:

Applied to E. coli strain WP2uvrA, without metabolic activation, only (at 10 µg per plate) Migrated to IUCLID6: in DMSO

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

Milli-Q water

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene in DMSO

Remarks:

Applied to all strains (1 µg per plate for S. typhimurium strains TA98, TA100 and TA1535; 2.5 µg per plate for S. typhimurium strain TA1537; 10 µg per plate for E. coli strain WP2uvrA), with metabolic activation

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Preincubation period: n/a
- Exposure duration: 48 h
- Fixation time (start of exposure up to fixation or harvest of cells): n/a

SELECTION AGENT (mutation assays): no data

NUMBER OF REPLICATIONS: triplicate

NUMBER OF CELLS EVALUATED: no data

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth

OTHER EXAMINATIONS:
- Determination of polyploidy: not relevant
- Determination of endoreplication: not relevant
- Other: no data

Evaluation criteria:

A test substance is considered positive (mutagenic) in the test if it induced at least a 2-fold, dose related increase in the number of revertants with respect to the number induced by the solvent control in any of the tester strains, either with or without metabolic activation. Any mean plate count of less than 20 is considered to be not biologically relevent. A test substance is considered to be negative (not mutagenic) if the total number of revertants in any tested strain at any concentration is not greater than two times the solvent control value, with or without metabolic activation. These results should be reproducible in at least one independently repeated experiment.

Statistics:

No formal hypothesis testing was performed.

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

without

Genotoxicity:

positive

Remarks:

platinum (2+) tetraamimine (SP-4-1) diacetate induced up to a 13-fold dose-related increase in the number of revertant colonies compared to the solvent control

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with

Genotoxicity:

positive

Remarks:

platinum (2+) tetraamimine (SP-4-1) diacetate induced up to a 18-fold dose-related increase in the number of revertant colonies compared to the solvent control

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 98

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with

Genotoxicity:

positive

Remarks:

platinum (2+) tetraamimine (SP-4-1) diacetate induced up to a 2.3-fold dose-related increase in the number of revertant colonies compared to the solvent control

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

without

Genotoxicity:

positive

Remarks:

platinum (2+) tetraamimine (SP-4-1) diacetate induced up to a 3.2-fold dose-related increase in the number of revertant colonies compared to the solvent control

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with

Genotoxicity:

positive

Remarks:

platinum (2+) tetraamimine (SP-4-1) diacetate induced up to a 6-fold dose-related increase in the number of revertant colonies compared to the solvent control

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Species / strain:

other: S. typhimurium TA100 and TA1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Effects of pH: no data
- Effects of osmolality: no data
- Evaporation from medium: no data
- Water solubility: no data
- Precipitation: platinum (2+) tetraamimine (SP-4-1) diacetate did not precipitate in top agar, or on plates at the start and end of the incubation period

RANGE-FINDING/SCREENING STUDIES: platinum (2+) tetraamimine (SP-4-1) diacetate caused no cytotoxicity in S. typhimurium strain TA100 or E. coli strain WP2uvrA when tested at up to 5 mg per plate

COMPARISON WITH HISTORICAL CONTROL DATA: laboratory background historical ranges were presented for negative (number of spontaneous revertants per plate) and positive control data for each of the tested strains. Experimental control results were compared to these values.

ADDITIONAL INFORMATION ON CYTOTOXICITY: no data

Conclusions:

In a GLP study performed according to OECD Test Guideline 471, tetraammineplatinum diacetate was mutagenic in Salmonella typhimurium strains TA98 and TA1537 and Escherichia coli strain WP2uvrA when tested aat up to 5 mg/plate in the presence and absence of metabolic activation.

Executive summary:

The genotoxic potential of tetraammineplatinum diacetate was analysed in a bacterial reverse mutation (Ames) assay, conducted according to OECD Test Guideline 471 and to GLP. A dose range finding test was performed using Salmonella typhimurium strain TA100 and Escherichia coli strain WP2uvrA. Triplicate cell cultures were exposed to tetraammineplatinum diacetate at up to 5000 µg/plate, both in the presence and absence of metabolic activation by rat liver fraction S9 (alongside appropriate vehicle and positive controls). These cultures were then inspected for signs of cytotoxicity and for the presence of revertant colonies. Since no cytotoxicity was observed, in the main experiment triplicate cultures of S. typhimurium strains TA98, TA1535 and TA1537 were exposed to the test material at concentrations of 100, 330, 1000, 3330 and 5000 µg/plate, both in the presence and absence of metabolic activation by S9 (alongside appropriate vehicle and positive controls), and were incubated for 48 hours at 37 °C before being inspected for signs of cytotoxicity and for the presence of revertant colonies.

Significant cytotoxicity was not observed for any of the tested strains, at any of the tested concentrations. Significant, dose-related increases in the number of observed revertant colonies were seen for S. typhimurium strains TA98 (up to 2.3 -fold in the presence of S9) and TA1537 (up to 13 -fold and 18 -fold in the absence and presence of S9 respectively), and E. coli strain WP2uvrA (up to 3.2 -fold and 6 -fold in the absence and presence of S9 respectively). No significant, dose-related increases were seen in S. typhimurium strain TA98 in the absence of S9, or in TA100 and TA1535 (both in the absence and presence of S9). Under the conditions of this assay, tetraammineplatinum diacetate showed mutagenic potential.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (positive)

Genetic toxicity in vivo

Description of key information

The in vivo genotoxicity of tetraammineplatinum dichloride, as evaluated by its ability to induce micronuclei in polychromatic erythrocytes and to cause DNA damage, was assessed in a study following OECD 474 and 489 and according to GLP. Male Wistar rats (5/group) were given gavage doses of 250, 500 or 1000 mg/kg bw/day of the test item on three consecutive days. Comet analyses were conducted on preparations of liver, glandular stomach, duodenum and kidney tissues.

There was no evidence of an increase in the incidence of micronucleated polychromatic erythrocytes. There was no increase in % tail intensity in the liver, glandular stomach or duodenum. 

There was a statistically significant and dose-related increase (p < 0.001) in DNA damage seen in the analysis of the kidney tissue. The tail intensity in animals dosed with 500 mg/kg bw/day was 14.56%, and in animals receiving 1000 mg/kg bw/day was 12.59%. However, these tail intensity values fell within the 95% confidence limits of the historical control data (upper limit 25.55%). Histopathological examination of the tissues did not reveal evidence of toxicity. As such, this finding was considered to be equivocal evidence of a genotoxic effect (Eurlings, 2020).

Link to relevant study records

Reference

Reference 1

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26 Feb 2020 - 30 Apr 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

Version / remarks:

29 July 2016

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

mammalian erythrocyte micronucleus test

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Lot/batch number of test material: 9005305492.
- Expiration date of the lot/batch: 07 January 2021.
- Purity test date: CoA issued 26 November 2019.

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: In refrigerator (2 - 8 °C)

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: None.
- Final preparation of a solid: Test item was suspended in corn oil.

FORM AS APPLIED IN THE TEST (if different from that of starting material) : Suspension.

Species:

rat

Strain:

Wistar

Details on species / strain selection:

The Wistar Han rat was the species and strain of choice because it is a readily available rodent which is commonly used for genotoxicity testing, with documented susceptibility to a wide range of toxic items. Moreover, historical control background data has been generated with this strain.

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, Sulzfeld, Germany.
- Age at study initiation: 6 weeks.
- Weight at study initiation: 138 ± 8.4 g (Mean body weight ± SD).
- Assigned to test groups randomly: Yes.
- Fasting period before study: No.
- Housing: Up to 5 animals of the same sex and in the same dosing group were housed together.
- Diet: Commercial pellets ad libitum, except during designated procedures.
- Water: Tap water, ad libitum.
- Acclimation period: At least 6 days.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18 to 24°C.
- Humidity (%): 40 to 70%.
- Air changes (per hr): ≥ 10.
- Photoperiod: 12 hrs light/12 hrs dark, except during designated procedures.

IN-LIFE DATES:
From: Not specified.
To: 09 Apr 2020.

Route of administration:

oral: gavage

Vehicle:

- Vehicle(s)/solvent(s) used: corn oil.
- Source of vehicle: Fagron Farmaceuticals, Capelle a/d IJssel, the Netherlands.

Duration of treatment / exposure:

Three consecutive days.

Frequency of treatment:

Daily.

Post exposure period:

Tissue samples taken 3 - 4 hours after administration of final dose.

Dose / conc.:

250 mg/kg bw/day (actual dose received)

Dose / conc.:

500 mg/kg bw/day (actual dose received)

Dose / conc.:

1 000 mg/kg bw/day (actual dose received)

Remarks:

Maximum tolerable dose. Mortality and severe toxicity were observed at doses of 1500 and 2000 mg/kg bw/day in a preliminary dose range finding study.

No. of animals per sex per dose:

5

Control animals:

yes, concurrent vehicle

Positive control(s):

Cyclophosphamide.
- Route of administration: Gavage.
- Doses / concentrations: A single dose of 19 mg/kg bw, dissolved in physiological saline.

Tissues and cell types examined:

Bone marrow from the femur.

Details of tissue and slide preparation:

The femurs were flushed with foetal calf serum and the cell suspension centrifuged. The supernatant was removed and a drop of the remaining cell suspension was spread across a clean slide and fixed with methanol. The slides were automatically stained with Giemsa using the Wright Stain Procedure.

Evaluation criteria:

The test item was considered positive if all of the following criteria were met:
a) at least one treatment group showed a statistically significant increase in frequency of micronucleated polychromatic erythrocytes.
b) the increase was dose related.
c) the results were outside the 95% confidence limits of the historical control data.

If none of the above criteria were met, the test item was considered negative.

The incidence of micronuclei was assessed in at least 4000 polychromatic erythrocytes per animal.

Key result

Sex:

male

Genotoxicity:

negative

Toxicity:

no effects

Vehicle controls validity:

valid

Positive controls validity:

valid

Additional information on results:

Platinum was quantifiable in plasma samples from high-dose (1000 mg/kg/day) satellite animals 1, 3, 6 and 12 hours after completing the second day of treatment. Moreover, platinum was quantifiable in plasma samples from all high-dose animals taken at necropsy approximately 3-4 hours after the third dose. Therefore it was confirmed that the animals were exposed to the test item. No test item was detected in the animals dosed with vehicle.
No statistically significant increase in the frequency of micronucleated polychromatic erythrocytes was observed. A slight increase was seen in all treatment groups that was within the 95% limits of the historical control data.

Treated animals showed no decrease in the PCE:NCE ratio, indicating a lack of toxicity to the bone marrow.

Conclusions:

Tetraammineplatinum dichloride did not induce an increase in micronucleated polychromatic erythrocytes in rats administered up to 1000 mg/kg bw/day by gavage on three consecutive days.

Executive summary:

The in vivo clastogenicity of tetraammineplatinum dichloride, as evaluated by its ability to induce micronuclei in polychromatic erythrocytes, was assessed in a study following OECD 474 and according to GLP. Male Wistar rats (5/group) were given gavage doses of 250, 500 or 1000 mg/kg bw/day of the test item on three consecutive days, or a vehicle control. The concurrent positive control group received a single dose of cyclophosphamide. Bone marrow was harvested from the femurs and assessed for micronuclei.

There was a slight but not statistically significant increase in micronucleated polychromatic erythrocytes in all treatment groups, but the incidences fell within the 95% limits of the historical control data. On that basis, tetraammineplatinum dichloride was concluded to be non-genotoxic under the conditions of this assay.

Reference 2

Endpoint:

in vivo mammalian cell study: DNA damage and/or repair

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26 Feb 2020 - 30 Apr 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

OECD Guideline 489 (In vivo Mammalian Alkaline Comet Assay)

Version / remarks:

29 July 2016.

Deviations:

yes

Remarks:

Only 3 or 4 animals were used for the isolation of the stomach in the control, low- and high-dose groups due to a technical error. All other values were within the historical controls and the results were clearly negative, so this did not impact the study

GLP compliance:

yes (incl. QA statement)

Type of assay:

mammalian comet assay

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Lot/batch number of test material:
9005305492.
- Expiration date of the lot/batch: 07 January 2021.
- Purity test date: CoA issued 26 November 2019.

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material:
In refrigerator (2 - 8 °C)

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing:
None.
- Final preparation of a solid: Test item was suspended in corn oil.

FORM AS APPLIED IN THE TEST (if different from that of starting material)
: Suspension.

Species:

rat

Strain:

Wistar

Details on species / strain selection:

The Wistar Han rat was the species and strain of choice because it is a readily available rodent which is commonly used for genotoxicity testing, with documented susceptibility to a wide range of toxic items. Moreover, historical control background data has been generated with this strain.

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, Sulzfeld, Germany.
- Age at study initiation: 6 weeks.
- Weight at study initiation: 138 ± 8.4 g (Mean body weight ± SD).
- Assigned to test groups randomly: Yes.
- Fasting period before study: No.
- Housing: Up to 5 animals of the same sex and in the same dosing group were housed together.
- Diet: Commercial pellets ad libitum, except during designated procedures.
- Water: Tap water, ad libitum.
- Acclimation period: At least 6 days.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18 to 24°C.
- Humidity (%): 40 to 70%.
- Air changes (per hr): ≥ 10.
- Photoperiod: 12 hrs light/12 hrs dark, except during designated procedures.

IN-LIFE DATES:
From: Not specified.
To: 09 Apr 2020.

Route of administration:

oral: gavage

Vehicle:

- Vehicle(s)/solvent(s) used: corn oil.
- Justification for choice of solvent/vehicle: corn oil is a widely used standard vehicle for in vivo animal experiments.
- Concentration of test material in vehicle: 27.1, 54.1 or 108 mg/g (corresponding to nominal concentrations of 25, 50 and 100 mg/mL)
- Amount of vehicle (if gavage or dermal): 10 mL/kg bw
- Stability of test item in vehicle: homogeneity of test item suspended in vehicle demonstrated for 4 hours (sufficient for the dosing of all test animals), after which unused test item formulations were discarded.

Duration of treatment / exposure:

Three consecutive days.

Frequency of treatment:

Daily.

Post exposure period:

Tissue samples taken 3 - 4 hours after administration of final dose.

Dose / conc.:

250 mg/kg bw/day (actual dose received)

Dose / conc.:

500 mg/kg bw/day (actual dose received)

Dose / conc.:

1 000 mg/kg bw/day (actual dose received)

Remarks:

Maximum tolerable dose. Mortality and severe toxicity were observed at doses of 1500 and 2000 mg/kg bw/day in a preliminary dose range finding study.

No. of animals per sex per dose:

5

Control animals:

yes, concurrent vehicle

Positive control(s):

Ethyl methanesulphonate.
- Route of administration: Gavage.
- Doses / concentrations: 200 mg/kg bw, dissolved in physiological saline, administered twice.

Tissues and cell types examined:

Cells were isolated from the liver, glandular stomach, duodenum and kidney.

Details of tissue and slide preparation:

Minced liver or kidney tissue was added to collagenase and dissolved in HBSS (saline). This suspension was shaken and centrifuged. The cell pellet was resuspended in HBSS and kept on ice prior to preparation of the slides.

Tissue from the glandular stomach and duodenum was stored on ice in "mincing buffer incomplete" (HBSS + EDTA). The surface epithelium of both the glandular stomach and duodenum was discarded as it contains a high proportion of apoptotic cells which distort the comet analysis. The cells, suspended in the buffer, were filtered though a 100 µm cell strainer and stored on ice prior to preparation of the slides.

Low melting point agarose was added to the cell suspensions and layered on a comet slide, which was then incubated for 10 - 35 minutes in the refrigerator.

Slides were kept overnight in the refrigerator, immersed in pre-chilled lysis solution. After rinsing, the slides were placed in freshly-prepared alkaline solution; electrophoresis was performed for 20 minutes (stomach and duodenum) or 30 minutes (liver and kidney). Following another rinse, the slides were immersed in absolute ethanol and allowed to dry, before staining with SYBR Gold fluorescent dye.

Evaluation criteria:

A test item was considered positive if all of the following criteria were met:
a) at least one treatment group demonstrated a statistically significant increase in % tail intensity vs. control.
b) the increase was dose-related.
c) any of the results were outside the 95% confidence limits of the historical control data.

If none of the above criteria were met, the test item was considered negative. If the data precluded making a conclusion of clearly positive or negative, the result was concluded as equivocal.

Key result

Sex:

male

Genotoxicity:

ambiguous

Remarks:

Kidney: Statistically significant and dose-related (p < 0.001 for the trend) increase in tail intensity, but the mean % tail intensity within the 95% limits of the historical control data. See table below

Toxicity:

no effects

Vehicle controls validity:

valid

Positive controls validity:

valid

Sex:

male

Genotoxicity:

negative

Remarks:

Liver: no statistically significant increase in % tail intensity.

Toxicity:

not examined

Vehicle controls validity:

valid

Positive controls validity:

valid

Sex:

male

Genotoxicity:

negative

Remarks:

Glandular stomach: no statistically significant increase in % tail intensity.

Toxicity:

not examined

Vehicle controls validity:

valid

Positive controls validity:

valid

Sex:

male

Genotoxicity:

negative

Remarks:

Duodenum: no statistically significant increase in % tail intensity.

Toxicity:

not examined

Vehicle controls validity:

valid

Positive controls validity:

valid

Additional information on results:

See tables 5 (negative control) and 6 (positive control), below, for historical control data.

Platinum was quantifiable in plasma samples from high-dose (1000 mg/kg/day) satellite animals 1, 3, 6 and 12 hours after completing the second day of treatment. Moreover, platinum was quantifiable in plasma samples from all high-dose animals taken at necropsy approximately 3-4 hours after the third dose. Therefore it was confirmed that the animals were exposed to the test item. No test item was detected in the animals dosed with vehicle.

Table 1: Comet results (% tail intensity) for kidney.

Dose	% Tail Intensity	S.D.
0 mg/kg bw/day (vehicle control)	3.52%	± 0.72%
250 mg/kg bw/day	7.56%	± 3.00%
500 mg/kg bw/day	14.56%	± 4.58%
1000 mg/kg bw/day	12.59%	± 6.09%
EMS (positive control)	79.86%	± 4.58%

 

Table 2: Comet results (% tail intensity) for liver.

Dose	% Tail Intensity	S.D.
0 mg/kg bw/day (vehicle control)	2.23%	± 0.43%
250 mg/kg bw/day	1.80%	± 0.44%
500 mg/kg bw/day	1.73%	± 0.25%
1000 mg/kg bw/day	1.80%	± 0.52%
EMS (positive control)	81.47%	± 1.67%

 

Table 3: Comet results (% tail intensity) for glandular stomach.

Dose	% Tail Intensity	S.D.
0 mg/kg bw/day (vehicle control)	3.14%	± 0.85%
250 mg/kg bw/day	4.44%	± 1.39%
500 mg/kg bw/day	4.37%	± 0.90%
1000 mg/kg bw/day	4.15%	± 0.35%
EMS (positive control)	52.70%	± 7.21%

 

Table 4: Comet results (% tail intensity) for duodenum.

Dose	% Tail Intensity	S.D.
0 mg/kg bw/day (vehicle control)	2.18%	± 0.28%
250 mg/kg bw/day	2.63%	± 0.85%
500 mg/kg bw/day	2.86%	± 0.93%
1000 mg/kg bw/day	2.47%	± 0.51%
EMS (positive control)	34.29%	± 4.51%

 

Table 5: Historical data Comet assay Negative control

	Liver Tail Intensity (%) Males and Females	Duodenum Tail Intensity (%) Males and Females	Stomach Tail Intensity (%) Males and Females	Kidney Tail Intensity (%) Males and Females
Mean	1.96	3.06	2.45	12.10
SD	0.92	1.52	1.39	8.46
n	85	45	60	30
Lower control limit (95% control limits)	0.27	-0.86	-1.07	-1.35
Upper control limit (95% control limits)	3.65	6.97	5.96	25.55

SD = Standard deviation

n = Number of observations

Kidney: Historical control data from experiments performed in Feb 2012 – July 2019

Liver, Stomach, Duodenum: Historical control data from experiments performed in Jan 2018 – July 2019

 

Table 6: Historical data Comet assay Positive control (200 mg/kg bw EMS orally dosed for two consecutive days)

	Liver Tail Intensity (%) Males and Females	Duodenum Tail Intensity (%) Males and Females	Stomach Tail Intensity (%) Males and Females	Kidney Tail Intensity (%) Males and Females
Mean	89.53	41.17	55.16	84.92
SD	6.89	14.03	14.23	13.82
n	80	44	59	30
Lower control limit (95% control limits)	79.70	20.78	34.74	72.81
Upper control limit (95% control limits)	99.36	61.56	78.58	97.03

SD = Standard deviation

n = Number of observations

Kidney: Historical control data from experiments performed in Feb 2012 – July 2019

Liver, Stomach, Duodenum: Historical control data from experiments performed in Jan 2018 – July 2019

Conclusions:

When tested in the comet assay, tetraammineplatinum dichloride did not induce an increase in DNA damage in the liver, glandular stomach or duodenum of rats administered up to 1000 mg/kg bw/day by gavage on three consecutive days. A statistically significant and dose-related (p < 0.001 for the trend) increase in DNA damage was seen in kidney cells, but the mean % tail intensity fell within the 95% limits of the historical control data. As such, this finding was considered to be equivocal evidence of a genotoxic effect.

Executive summary:

The potential for tetraammineplatinum dichloride to cause DNA damage was evaluated in a study following OECD 489 and according to GLP. Male Wistar rats (5/group) were given gavage doses of 250, 500 or 1000 mg/kg bw/day of the test item on three consecutive days, or a vehicle control. The concurrent positive control group received two doses of EMS (200 mg/kg bw/day). Comet analyses were conducted on preparations of liver, glandular stomach, duodenum and kidney tissues.

There was no increase in % tail intensity in the liver, glandular stomach or duodenum, indicating that the test item is not genotoxic to these tissues.

There was a statistically significant and dose-related increase (p < 0.001) in DNA damage seen in the analysis of the kidney tissue. The tail intensity in animals dosed with 500 mg/kg bw/day was 14.56%, and in animals receiving 1000 mg/kg bw/day was 12.59%. However, these tail intensity values fell within the 95% confidence limits of the historical control data (upper limit 25.55%). As such, this finding was considered to be equivocal evidence of a genotoxic effect. No toxicity was observed in histopathological examination of the kidney tissues, indicating that this can be excluded as an indirect cause of the reported DNA damage.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Mode of Action Analysis / Human Relevance Framework

No data identified.

Additional information

Only certain in vitro and no in vivo genotoxicity data were identified for tetraammineplatinum(II) diacetate. However, a number of genotoxicity studies (both in vitro and in vivo) were identified for tetraammineplatinum(II) dichloride and hydrogen carbonate. Tetraammineplatinum dichloride and hydrogen carbonate are considered to fall within the scope of the read-across category "tetraammineplatinum(II) salts". See section 13 in IUCLID for full read-across justification report.

 

The in vivo genotoxicity of tetraammineplatinum dichloride, as evaluated by its ability to induce micronuclei in polychromatic erythrocytes and to cause DNA damage, was assessed in a study following OECD 474 and 489 and according to GLP. Male Wistar rats (5/group) were given gavage doses of 250, 500 or 1000 mg/kg bw/day of the test item on three consecutive days. Comet analyses were conducted on preparations of liver, glandular stomach, duodenum and kidney tissues.

There was no evidence of an increase in the incidence of micronucleated polychromatic erythrocytes. There was no increase in % tail intensity in the liver, glandular stomach or duodenum. 

There was a statistically significant and dose-related increase (p < 0.001) in DNA damage seen in the analysis of the kidney tissue. The tail intensity in animals dosed with 500 mg/kg bw/day was 14.56%, and in animals receiving 1000 mg/kg bw/day was 12.59%. However, these tail intensity values fell within the 95% confidence limits of the historical control data (upper limit 25.55%). Histopathological examination of the tissues did not reveal evidence of toxicity. As such, this finding was considered to be equivocal evidence of a genotoxic effect (Eurlings, 2020).

Justification for classification or non-classification

Based on the existing data set, tetraammineplatinum(II) diacetate does not currently meet the criteria for classification as a germ cell mutagen under EU CLP criteria (EC 1272/2008).