Di(tetraethylammonium)hexahydroxoplatinate(IV)

Genetic toxicity: in vivo

Administrative data

Endpoint:

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

Type of information:

experimental study

Adequacy of study:

key study

Study period:

11 Feb 2020 - 29 Jun 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Report date:

2020

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 489 (In vivo Mammalian Alkaline Comet Assay)

Version / remarks:

29 July 2016.

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

mammalian comet assay

Test material

Test material information

Constituent 1

Reference substance name:

Dihydrogen hexahydroxyplatinate, compound with 2-aminoethanol (1:2)

EC Number:

268-717-3

EC Name:

Dihydrogen hexahydroxyplatinate, compound with 2-aminoethanol (1:2)

Cas Number:

68133-90-4

Molecular formula:

C2H7NO.1/2H6O6Pt.H

IUPAC Name:

dihydrogen hexahydroxyplatinate(2-) - 2-aminoethanol (1:2)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Lot/batch number of test material:
19267COLPT.
- Expiration date of the lot/batch: 01 October 2021.
- Purity test date: CoA issued 17 December 2019.

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: At room temperature.

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.

Test animals

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: 171 ± 8.7 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): 19 to 25°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: 12 Mar 2020.

Administration / exposure

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.

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

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

Doses / concentrations 2

Dose / conc.:

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

Doses / concentrations 3

Dose / conc.:

2 000 mg/kg bw/day (actual dose received)

Remarks:

No treatment-related toxicity or mortality were seen in a preliminary dose range finding study in which three male and three female rats received three consecutive daily doses of 2000 mg/kg bw

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.

Examinations

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 13 - 39 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, and direct or indirect evidence supportive of exposure of, or toxicity to, the target tissues was demonstrated, the test item was considered negative. If the data precluded making a conclusion of clearly positive or negative, the result was concluded as equivocal.

Results and discussion

Test results

Test results 1

Key result

Sex:

male

Genotoxicity:

negative

Remarks:

Kidney: no statistically significant increase in % tail intensity.

Toxicity:

no effects

Vehicle controls validity:

valid

Positive controls validity:

valid

Test results 2

Key result

Sex:

male

Genotoxicity:

negative

Remarks:

Liver: no statistically significant increase in % tail intensity.

Toxicity:

not examined

Vehicle controls validity:

valid

Positive controls validity:

valid

Test results 3

Key result

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

Test results 4

Key result

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:

Platinum was quantifiable in plasma samples from high-dose (2000 mg/kg bw/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 target tissues were exposed to the test item. No test item was detected in the animals dosed with vehicle.

Any other information on results incl. tables

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

Applicant's summary and conclusion

Conclusions:

When tested in the comet assay, dihydrogen hexahydroxyplatinate, compound with 2-aminoethanol, did not induce an increase in DNA damage in the liver, kidney, glandular stomach or duodenum of rats administered up to 2000 mg/kg bw/day by gavage on three consecutive days. As such, this compound was considered to negative under the conditions of this assay.

Executive summary:

The potential for dihydrogen hexahydroxyplatinate, compound with 2-aminoethanol, 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 500, 1000 or 2000 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, kidney, glandular stomach or duodenum, indicating that the test item is not genotoxic to these tissues.