2,3,4-trihydroxybenzophenone

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / bone marrow chromosome aberration

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14 Dec 1987 - 06 Jan 1988

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

(2 sampling times instead of the recommended 3; 50 metaphases counted while 200 is recommended; the cell cycle length not given; 500 cells scored for MI while 1000 is recommended; no cytotoxicity observed in bone marrow based on MI)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1988

Report date:

1988

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 475 (Mammalian Bone Marrow Chromosome Aberration Test)

Version / remarks:

adopted Jul 2016

Deviations:

yes

Remarks:

(2 sampling times instead of the recommended 3; 50 metaphases counted while 200 is recommended; the cell cycle length not given; 500 cells scored for MI while 1000 is recommended; no cytotoxicity observed in bone marrow based on MI)

GLP compliance:

yes

Type of assay:

mammalian bone marrow chromosome aberration test

Test material

Test material information

Constituent 1

Reference substance name:

2,3,4-trihydroxybenzophenone

EC Number:

214-540-1

EC Name:

2,3,4-trihydroxybenzophenone

Cas Number:

1143-72-2

Molecular formula:

C13H10O4

IUPAC Name:

4-benzoylbenzene-1,2,3-triol

Test material form:

solid

Test animals

Species:

hamster, Chinese

Strain:

other: Chinese hamster inbred strain

Details on species / strain selection:

The Chinese hamster is an animal which has been used for many years as suitable experimental animal in cytogenetic investigations. This species, although little used in other aspects of toxicology, has a karyotype with 22 chromosomes all of which are easily identified. This offers the opportunity to reduce observer errors and the time required for the cytogenetic analysis.

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: LMP stock
- Age at study initiation: Minimum 10 weeks
- Weight at study initiation: Approximately 25 g
- Fasting period before study: Yes, animals received no food approximately 18 h beore treatmen with the test substance.
- Housing: The animals were individually housed in Makrolon Type I cages with wire mesh top (EBECO, Castrop-Rauxel, Germany) on granulated soft wood bedding (Altromin, Lage/Lippe, Germany).
- Diet: Pelleted standard diet (Altromin, Lage/Lippe, Germany)
- Water: Tap water, ad libitum
- Acclimation period: Minimum 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 ± 3
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

- Vehicle(s)/solvent(s) used: Methocel MC
- Justification for choice of solvent/vehicle: The vehicle was chosen to its relative nontoxicity for the animals.
- Amount of vehicle: 20 mL/kg bw

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: On the day of the experiment, the test substance was suspended in 0.5 % Methocel solution. All animals received a single standard dose volume adjusted to the body weight orally.

Duration of treatment / exposure:

not applicable

Frequency of treatment:

single treatment

Post exposure period:

24 and 48 h after treatment

Doses / concentrations

Dose / conc.:

4 000 mg/kg bw/day (nominal)

No. of animals per sex per dose:

6

Control animals:

yes, concurrent vehicle

Positive control(s):

cyclophosphamide
- Route of administration: oral
- Doses / concentrations: 30 mg/kg bw in physiological saline

Examinations

Tissues and cell types examined:

Tissue: bone marrow
Cell type: bone marrow cells

Details of tissue and slide preparation:

CRITERIA FOR DOSE SELECTION: A range finding study was performed to find the maximum tolerated dose of the test substance based on mortality. In the first pre-experiment 2 males and 2 females were treated with 5000 mg/kg bw. In the second pre-experiment 10 males were exposed to 5000 mg/kg bw and in the third pre-experiment 2 males and 2 females received 4000 mg/kg bw.

DETAILS OF SLIDE PREPARATION: Following treatment and prior to sample collection, animals were injected intraperitoneally with 2 mg/mL Colcemid®, and samples were collected 2.5 hours thereafter. Cells were harvested from the bone marrow, swollen, fixed and stained, and analysed for chromosomal aberrations.

METHOD OF ANALYSIS: At least 50 well spread metaphases were analysed per animal by use of NIKON microscopes with 100x oil immersion objectives and were scored for structural chromosome aberrations (gaps, breaks, fragments, deletions, exchanges and chromosomal disintegrations).

Evaluation criteria:

The test article is classified as mutagenic if it induces a significantly increased aberration rate with at least one of the concentrations tested as compared with the negative control.
This can be confirmed by means of the nonparametric Mann-Whitney test. A test article which produces no significant positive response at any test point is regarded as non-mutagenic in this assay.

Statistics:

Statistical analysis was not performed due to the obtained results.

Results and discussion

Test results

Key result

Sex:

male/female

Genotoxicity:

negative

Toxicity:

no effects

Vehicle controls validity:

valid

Negative controls validity:

not applicable

Positive controls validity:

valid

Additional information on results:

RESULTS OF RANGE-FINDING STUDY
- Dose range: 4000 and 5000 mg/kg bw
- Solubility: Suspension in 0.5% Methocel solution
- Clinical signs of toxicity in test animals: Reduction of spontaneous activity, apathy and abdominal position were observed in both dose groups. 1/2 males of the first pre-experiment and 5/10 males of the second pre-experiment died at 5000 mg/kg bw. None of the exposed animals died at 4000 mg/kg bw.

Any other information on results incl. tables

Table 1: Summary of results

Dose (mg/kg bw)	Postexposure period [h]	Number of cells scored	Aberrant cells incl. gaps (%)	Aberrant cells excl. gaps (%)	Mitotic index (%)
4000	24	500	0.6	0.0	5.50
4000	48	500	2.2	0.4	6.51
Negative control	24	500	2.4	1.2	5.60
Positive control	24	500	13.4	9.8	5.28